Search

Background: Pes planovalgus (PV) deformity accounts for lever arm dysfunction and compromises gait in patients with cerebral palsy (CP). However, the association between ankle power generation and radiographic indices is not yet understood. We aimed to investigate the association between ankle power and radiographic indices during gait in patients with CP concomitant with PV deformity., Methods: Patients older than 14 years with ambulatory CP and PV deformity were included. All the patients underwent 3-dimensional gait analysis and weight-bearing foot radiography. Gait data were collected, including foot progression angle, tibial rotation, hip rotation, and ankle power generation. Radiographic measurements included anteroposterior (AP) talo-first metatarsal angle, lateral talo-first metatarsal angle, and hindfoot angle. A linear mixed-effects model was performed to identify significant radiographic indices associated with ankle power generation., Results: Thirty-one limbs from 15 patients with spastic diplegia and 6 with spastic hemiplegia were included. Statistical analysis demonstrated that ankle power generation was significantly correlated with the CP type ( P =0.0068) and AP talo-1 st metatarsal angle ( P =0.0230)., Conclusion: Ankle power generation was significantly associated with the AP talo-first metatarsal angle. Surgeons might need to pay attention to correcting forefoot abduction to restore ankle power when planning surgeries for pes PV deformities in patients with CP., Level of Evidence: Prognostic Level III., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

We aimed to investigate the progression of patella alta (PA) in patients with cerebral palsy (CP) using the Koshino-Sugimoto (KS) index and assess associated risk factors. Participants in our retrospective study met the following inclusion criteria: patients with CP who visited our institute from May 2003 to December 2019, were ≤18 years of age, were followed up for >2 years and had at least two lateral knee radiographs. KS indices of both knee radiographs were measured for each patient. A linear mixed model was implemented. Our participants included 222 CP patients. KS index values were measured via 652 knee radiographs. Reference values of the KS index for those between 4 and 18 years of age were determined according to Gross Motor Function Classification System (GMFCS) levels. In all GMFCS levels, the KS index decreased with patients' ages (P < 0.0001). In groups where the KS index increased, GMFCS levels IV (P = 0.0045) and V (P = 0.0040) were statistically significant. Change in the KS index values indicates that PA improves as patients age within all GMFCS levels. However, in patients with GMFCS levels of IV and V, progressive PA is expected., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Backgroud: Single-event multilevel surgery (SEMLS) and hip reconstructive surgery (HRS) often cause intraoperative bleeding, consequently increasing the probability of transfusion and postoperative laboratory changes. Therefore, it is important to assess risk factors to predict the amount of blood loss. This study aimed to evaluate blood loss, its influencing factors, and the related laboratory changes during SEMLS and HRS in patients with cerebral palsy (CP)., Methods: We retrospectively examined consecutive CP patients who underwent SEMLS and HRS. Surrogate markers of blood loss, including preoperative and postoperative hemoglobin (Hb), hematocrit, and changes in Hb concentration, were assessed. Albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and creatine levels were also analyzed for related laboratory changes. Risk factors were analyzed using multiple regression and logistic regression models., Results: The overall cohort comprised 1,188 patients. Of them, 1,007 and 181 underwent SEMLS and HRS, respectively. Furthermore, 72 of 181 patients underwent a concomitant Dega osteotomy. The regression model showed that low preoperative Hb concentration ( p < 0.001), high albumin level ( p = 0.007), low body mass index (BMI) ( p = 0.002), and bilateral HRS ( p < 0.001) were significant risk factors of postoperative anemia. Valproate medication was associated with Hb drop, and the risk factors for Hb level < 8 g/dL on postoperative day 2 were bilateral HRS and Dega osteotomy in the HRS subgroup. In total, 21.6% had elevated AST levels on postoperative day 2, and bilateral HRS ( p < 0.001), Gross Motor Function Classification System (GMFCS) level V ( p = 0.041), Dega osteotomy ( p < 0.001), and high preoperative AST level ( p < 0.001) increased the risk of AST elevation., Conclusions: We have summarized the estimated blood loss and related laboratory changes after SEMLS and HRS in patients with CP and identified the risk factors. Clinical guidelines should be accordingly developed to include assessment of these risk factors and their impact in the outcomes of CP patients undergoing SEMLS and HRS., Competing Interests: CONFLICT OF INTEREST: No potential conflict of interest relevant to this article was reported., (Copyright © 2021 by The Korean Orthopaedic Association.)

Background: Gait deviation and associated torsional problems are common in patients with cerebral palsy (CP). Although femoral anteversion in CP has been extensively reviewed in previous studies, only a few studies have focused on tibial torsion. Therefore, this study aimed to evaluate tibial torsion in patients with CP and investigate the affecting factors., Methods: Consecutive patients with cerebral palsy who underwent 3-dimensional computed tomography for the assessment of rotational profiles were reviewed. Femoral anteversion and tibial torsion were measured, and the demographic characteristics of the patients were recorded. A linear mixed model was implemented to overcome the retrospective nature of the study., Results: After the implementation of inclusion and exclusion criteria, 472 patients were enrolled for this study. With age, external tibial torsion increased, while femoral anteversion decreased. The factors affecting external tibial torsion were increased femoral anteversion (p = 0.0057), increased age (p < 0.0001), higher Gross Motor Function Classification System (GMFCS) level (p < 0.0001), and involved/uninvolved limbs of hemiplegia (p = 0.0471/p = 0.0047)., Conclusions: Older age, GMFCS level IV/V, hemiplegia, and increased femoral anteversion were the independent risk factors of increased external tibial torsion; therefore, performing an imaging study is recommended for assessing the extent of tibial torsion in patients with such characteristics., (© 2021. The Author(s).)

Aims: Hip displacement, common in patients with cerebral palsy (CP), causes pain and hinders adequate care. Hip reconstructive surgery (HRS) is performed to treat hip displacement; however, only a few studies have quantitatively assessed femoral head sphericity after HRS. The aim of this study was to quantitatively assess improvement in hip sphericity after HRS in patients with CP., Methods: We retrospectively analyzed hip radiographs of patients who had undergone HRS because of CP-associated hip displacement. The pre- and postoperative migration percentage (MP), femoral neck-shaft angle (NSA), and sphericity, as determined by the Mose hip ratio (MHR), age at surgery, Gross Motor Function Classification System level, surgical history including Dega pelvic osteotomy, and triradiate cartilage status were studied. Regression analyses using linear mixed model were performed to identify factors affecting hip sphericity improvement., Results: A total of 108 patients were enrolled. The mean preoperative MP was 58.3% (SD 31.7%), which improved to 9.1% (SD 15.6%) at the last follow-up. NSA and MHR improved from 156.5° (SD 11.5°) and 82.3% (SD 8.6%) to 126.0° (SD 18.5°) and 89.1% (SD 9.0%), respectively. Factors affecting the postoperative MHR were preoperative MP (p = 0.005), immediate postoperative MP (p = 0.032), and history of Dega osteotomy (p = 0.046)., Conclusion: We found that hip sphericity improves with HRS. Preoperative MP, reduction quality, and acetabular coverage influence femoral head remodelling. We recommend that surgeons should consider intervention early before hip displacement progresses and that during HRS, definite reduction and coverage of the femoral head should be obtained. Cite this article: Bone Joint J 2021;103-B(1):198-203.

Background: Pathologic gait is common in patients with cerebral palsy (CP). Single-event multilevel surgery (SEMLS) is a combination of surgical procedures to improve pathologic gait in patients with CP. However, the effect of each procedure is difficult to predict. The gait deviation index (GDI) is useful in comparing pre- and postoperative improvement., Research Question: In this study, we evaluated the degree of GDI improvement in patients with CP and analyzed factors related to surgical outcomes., Methods: We screened patients seen between May 2003 and December 2019 via a clinical data warehouse to identify those with CP who had been followed up for >1 year and who had undergone SEMLS. The inclusion criteria were (1) CP patients with GMFCS levels I, II and III, (2) patients who underwent SEMLS, (3) and patients who underwent 3D gait analyses preoperatively and at least 1 year postoperatively. A linear mixed model was used to model GDI improvement, assess effects of covariates, and examine factors that contributed to improvement., Results: Overall, 544 patients were included. The average improvement in overall GDI was 8.9 ± 12.3, 9.6 ± 12.0, and 6.4 ± 8.6 in Gross Motor Function Classification System (GMFCS) levels I, II, and III, respectively. In GMFCS level II patients, GDI improvement decreased by 0.26 points with a 1-year delay in surgery (p = 0.0022). Within each group of GMFCS levels, femoral derotation osteotomy (FDO) was a significant factor in GDI improvement in GMFCS levels I and II. Rectus femoris transfer (RFT) and supracondylar extension osteotomy (SCO) were significant factors in GMFCS level II. No single procedure was shown to affect improvement in GMFCS level III., Significance: Postoperative GDI improved in all levels of GMFCS. Particular procedures especially affected postoperative improvement in GDI in levels I and II. Our data do not mean to set an indication for particular procedures; however, in GMFCS levels I, II patients, particular procedures, such as FDO, yielded a greater GDI improvement in our data set., Competing Interests: Declaration of Competing Interest The authors have nothing to declare., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Analyzing radiographic changes of pes planovalgus(PV) deformity of cerebral palsy(CP) patients according to age and influencing factors., Methods: CP patients with PV deformity younger than 18 years old who had undergone more than a year of follow-up with at least two standing foot radiographs were included. Anteroposterior and lateral talo-first metatarsal(talo-1stMT), talo-second metatarsal(talo-2ndMT), and hallux valgus(HV) angles were measured on the radiographs. The rate of progression was adjusted by multiple factors using the linear mixed model, with the Gross Motor Function Classification System(GMFCS) level as the fixed effect and age and each subject as random effects., Results: Overall, 194 patients were enrolled in this study, and 1272 standing foot radiographs were evaluated. The AP talo-2 nd MT angle progressed by 0.59° (p < 0.0001) and 0.64° (p = 0.0007) in GMFCS level II and III patients, respectively; however, there was no significant change in GMFCS level I patients (p = 0.3269). HV was significantly affected by age in all three GMFCS groups; it increased by 0.48° (p < 0.0001), 0.66° (p < 0.0001), and 1.19° (p < 0.0001) for levels I, II, and III, respectively. The lateral talo-1stMT angle showed improvements in GMFCS level I and II patients (0.43°, p < 0.0001, and 0.61°, p < 0.0001, respectively). In GMFCS level III patients, there was no significant improvement in the lateral talo-1 st MT angle (p = 0.0535)., Conclusions: The GMFCS level was the single most important factor influencing the progression of radiographic indices in PV deformity in CP. The AP talo-1 st MT and talo-2ndMT angles progressed in patients with GMFCS levels II and III. Physicians should take this result into consideration when planning the timing of the surgery., Level of Evidence: Prognostic Level IV.

Background: Precise measuring and monitoring of physical activity (PA) in patients with cerebral palsy (CP) are critical for assessing their PA participation and its potential health benefits. Accelerometer-based assessment of PA has been considered valid, reliable, and practical in children with CP. Therefore, we investigated the correlation between accelerometer- and questionnaire-based assessment of PA in CP patients., Methods: Nineteen patients with CP who were classified as Gross Motor Function Classification System level I-III and 84 normally developed participants were included in the study. Study participants wore an accelerometer for seven days, after which they visited the hospital and completed the International Physical Activity Questionnaire (IPAQ). CP patients and their caregivers completed the Pediatric Outcomes Data Collection Instrument (PODCI) and the Caregiver Priorities and Child Health Index of Life with Disabilities, respectively. The concurrent validity of the questionnaires was assessed., Results: In the accelerometer-based assessment, time spent in PA was significantly shorter at every intensity level in CP patients than in normally developed participants. However, PA assessed by the IPAQ was significantly higher in patients with CP, indicating that they tend to exaggerate their participation in PA. On the correlation of the assessment by the accelerometer and by the PODCI, transfer/basic mobility, sports/physical function, and happiness increased significantly as the number of steps taken and the distance travelled increased., Conclusions: In patients with CP, happiness and quality of life are associated with higher levels of PA. Thus, programs for patients with CP should focus on improving their PA., Competing Interests: CONFLICT OF INTEREST: No potential conflict of interest relevant to this article was reported., (Copyright © 2020 by The Korean Orthopaedic Association.)

Background: Some patients with cerebral palsy (CP) exhibit excessive knee flexion at initial contact followed by knee hyperextension (KE) in mid-stance., Research Question: This study investigated the change in sagittal kinematics after distal hamstring lengthening (DHL) and triceps surae lengthening procedures in CP patients with KE, and compared it to those without KE. In addition, the risk factors for the worsening of postoperative KE were analyzed., Methods: Consecutive 312 patients (596 limbs) with CP who underwent DHL and triceps surae lengthening were included. All patients underwent preoperative and 1-year postoperative three-dimensional gait analysis. Patients' limbs were divided into the KE and knee flexion (KF) groups, according to preoperative minimum knee flexion in stance. KE was defined as minimum knee flexion in stance less than 0°., Results: The KE and KF groups included 130 and 466 limbs, respectively. Knee and ankle sagittal kinematics significantly improved after surgery in both groups. Minimum knee flexion in stance significantly increased from -6.6˚ to 0.5˚ in the KE group, but decreased from 14.6˚ to 7.8˚ in the KF group. Among the KE group, minimum knee flexion in stance improved in 103 limbs (79.2 %), but worsened in 27 limbs (20.8 %). Degree of preoperative KE was the only factor significantly associated with postoperative worsening of KE (p=0.002). The cutoff value for the worsening of KE was -5.8˚ of preoperative minimum knee flexion in stance., Significance: This study demonstrated that the sagittal kinematics of the knee and ankle joints improved after DHL and triceps surae lengthening procedures in CP patients with and without KE. Preoperative degree of KE was a risk factor for the worsening of KE after surgery. Therefore, careful selection for indication of DHL is required to prevent postoperative KE due to overlengthening of the hamstrings, particularly in patients with severe preoperative KE., Competing Interests: Declaration of Competing Interest There were no conflicts of interest in the preparation of this study., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: Gait disturbances, including flexed knee gait, stiff knee gait, and tip-toeing gait, are common in patients with cerebral palsy (CP). There has been no reports regarding kinematic changes in the transverse plane after soft tissue surgeries, such as distal hamstring lengthening (DHL), rectus femoris transfer (RFT), and tendo-Achilles lengthening (TAL). This study aimed to evaluate changes in the transverse plane after soft tissue surgery in patients with CP by assessing the effects of the DHL, RFT, and TAL., Methods: The study enrolled 156 consecutive patients (mean age, 8.4 years; range, 4.4 to 20.9), representing 213 operated limbs, who underwent soft tissue surgery including DHL with semitendinosus transfer, RFT, and TAL. All patients were assessed by preoperative and 1-year postoperative three-dimensional gait analysis. Changes in transverse plane kinematics after soft tissue surgery and affecting factors were analyzed., Results: Sagittal kinematics including knee flexion at initial contact, ankle dorsiflexion at initial contact, and mean ankle dorsiflexion in the stance phase were significantly improved after single event multilevel surgery (all p < 0.001). Transverse kinematics, including mean tibial rotation and foot progression angle, were significantly improved to a more external angle after soft tissue surgeries (- 2.9°, p = 0.004 and - 9.5°, p < 0.001). The mean hip rotation was significantly improved to a more external angle by RFT (- 4.7°, p = 0.010) and the foot progression angle was significantly improved to a more external angle by TAL (- 3.9°, p = 0.028)., Conclusions: This study found that the transverse kinematics were improved to a more external angle after soft tissue surgery in patients with CP. Therefore, clinicians should consider that soft tissue surgery can affect the transverse plane kinematics in patients with CP. To confirm our findings, further research regarding the natural history of femoral and tibial torsion in children with CP is needed.

Background: Dega pelvic osteotomy is commonly performed procedure in patients with cerebral palsy (CP) undergoing hip reconstructive surgery for hip displacement. However, there has been no study investigating the outcomes after Dega pelvic osteotomy using allograft in patients with CP. This study investigated the outcomes of Dega pelvic osteotomy using iliac crest allograft in CP with hip displacement and the factors affecting allograft incorporation., Methods: This study included 110 patients (150 hips; mean age 8y7mo; 68 males, 42 females) who underwent hip reconstructive surgeries including Dega pelvic osteotomy using iliac crest allograft. To evaluate the time of allograft incorporation, Goldberg score was evaluated according to the follow-up period on all postoperative hip radiographs. The acetabular index, migration percentage, and neck-shaft angle were also measured on the preoperative and postoperative follow-up radiographs., Results: The mean estimated time for allograft incorporation (Goldberg score ≥ 6) was 1.1 years postoperatively. All hips showed radiographic union at the final follow-up and there was no case of graft-related complications. Patients with Gross Motor Function Classification System (GMFCS) level V had 6.9 times higher risk of radiographic delayed union than those with GMFCS level III and IV. Acetabular index did not increase during the follow-up period (p = 0.316)., Conclusions: Dega pelvic osteotomy using iliac crest allograft was effective in correcting acetabular dysplasia, without graft-related complications in patients with CP. Furthermore, the correction of acetabular dysplasia remained stable during the follow-up period.

The present study aimed to evaluate bone mineral density (BMD) in children and adolescents with cerebral palsy (CP) and to critically analyze the effects of a variety of factors, particularly the Gross Motor Function Classification System (GMFCS) level, the Caregiver Priorities and Child Health Index of Life with Disabilities questionnaire, and the Pediatric Outcomes Data Collection Instrument (PODCI), on BMD. Fifty patients with CP who underwent dual-energy X-ray absorptiometry were included. Collected data included the extent of involvement, muscle tone, demographic data, factors determined through chart review, and laboratory results. Factors associated with BMD in this group were analyzed by performing multiple regression analysis. The mean Z-scores in male and female patients were -3.252 ± 1.822 and -3.789 ± 1.764, respectively, in the proximal part of the femur and -2.219 ± 1.323 and -2.451 ± 1.434, respectively, in the lumbar spine. In multiple regression analysis, the GMFCS level and the average frequency of missed school in the PODCI were significant factors associated with both femur and lumbar spine BMD. Both the GMFCS level and school attendance were independently associated with BMD and should be considered for the prevention and management of osteoporosis in patients with CP., (Copyright © 2016. Published by Elsevier Inc.)

Background: Femoral derotation osteotomy (FDO) is generally reported to be excellent for correcting the hip rotation and foot progression angles in children with cerebral palsy (CP). However, it is unclear how long the favorable outcomes are maintained., Research Question: This study was performed to evaluate the long-term outcomes at more than 10 years after FDO in children with CP., Methods: FDO, as part of single event multilevel surgery to improve gait function, was performed at the intertrochanteric level with the patient in the prone position. The goal of the index surgery was femoral anteversion of 15°, measured using a modified trochanteric prominence angle test intraoperatively. All patients underwent three-dimensional gait analysis preoperatively and at 1 year and over 10 years postoperatively., Results: Thirty-four ambulatory patients (53 hips) with CP undergoing FDO were included. The mean age at surgery was 7.8 years (SD = 3.0 years) and mean follow-up duration was 12.9 years (SD = 2.7 years). The mean hip rotation decreased significantly from 9.6° preoperatively to 3.1° at 1 year postoperatively (p = 0.004), and decreased significantly to -5.9° at the final follow-up (p < 0.001). The mean foot progression in stance decreased from 7.9° preoperatively to -7.4° at 1 year postoperatively (p < 0.001), and was maintained at -10.9° at the final follow-up. The GDI significantly improved from 68.2 preoperatively to 83.4 1 year postoperatively (p < 0.001), and was maintained at 82.3 at the final follow-up. No patients underwent revision surgery due to recurrence of rotation deformity., Significance: Proximal FDO performed in the prone position provides favorable long-term outcomes at more than 10 years postoperatively, without recurrence of rotation deformity. To avoid under-correction or recurrence due to insufficient derotation, surgeons should consider not only dynamic gait analysis findings but also the measurement of anatomic femoral anteversion during intraoperative derotation., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Calcaneal lengthening (CL) is one of the treatment options for planovalgus deformity in patients with cerebral palsy (CP). However, its indication still needs to be clarified according to the functional status of CP. The aim of this study was to investigate the radiographic outcome after CL in patients with CP and to evaluate the risk factors causing undercorrection of planovalgus deformities. We included consecutive patients with CP who underwent CL for planovalgus deformity, were followed for more than 2 years, and had preoperative and postoperative weight-bearing anteroposterior (AP) and lateral foot radiographs. Six radiographic indices were used to assess the radiographic outcome. The patient age, sex, and Gross Motor Function Classification System (GMFCS) level were evaluated as possible risk factors, and we controlled for the interaction of potentially confounding variables using multivariate analysis. A total of 44 (77 feet) patients were included in this study. The mean age of the patients at the time of surgery was 10.5±4.0 years and the mean follow-up was 5.1±2.2 years. Patients with GMFCS III/IV achieved less correction than those with GMFCS I/II in the AP talus-first metatarsal angle (P=0.001), lateral talocalcaneal angle (P=0.028), and the lateral talus-first metatarsal angle (P<0.001). The rate of undercorrection in the GMFCS III/IV group was 1.6 times higher than that in the GMFCS I/II group in the AP talus-first metatarsal angle (odds ratios: 1.6; 95% confidence interval: 1.2-2.0; P<0.001) and 1.6 times higher in the lateral talus-first metatarsal angle (odds ratios: 1.6; 95% confidence interval: 1.3-1.9; P<0.001). In GMFCS I/II patients with CP, we found CL to be an effective procedure for the correction of planovalgus foot deformities. However, in GMFCS III/IV patients with planovalgus deformities, CL appears to be insufficient on the basis of the high rate of undercorrection in these patients. For patients with GMFCS level III/IV, additional or alternative procedures should be considered to correct the deformity and maintain the correction achieved., Level of Evidence: Level III, therapeutic study.

Background: Concurrent prophylactic femoral varization osteotomy (FVO) for stable hips has been performed in patients with cerebral palsy (CP) undergoing hip reconstructive surgery for the contralateral displaced hip. However, there is currently a lack of studies investigating the outcome after the prophylactic FVO in stable hip. This study investigated the outcomes after FVO in stable hips with CP and influencing factors. In addition, this study compared the outcomes with those after hip reconstructive surgery in the contralateral displaced hip., Methods: This study included 119 CP patients with 224 hips (80 stable, 144 displaced) undergoing hip reconstructive surgery including FVO. Migration percentage (MP), neck-shaft angle (NSA), and head-shaft angle (HSA) were measured through preoperative and follow-up hip radiographs. All hips were divided into the stable (MP ≤ 33%) and displaced hip groups (MP > 33%) according to the preoperative radiographs, and the annual changes in the radiographic indices after FVO were analyzed., Results: In stable hip group, MP did not significantly increase over time (p = 0.057) after prophylactic FVO. In displaced hip group, MP significantly increased over time (1.6%/year, p < 0.001). MP was significantly decreased in cases of concomitant Dega pelvic osteotomy in both stable (14.5%, p < 0.001) and displaced hips (18.9%, p < 0.001)., Conclusions: Prophylactic FVO in the stable hip in patients with CP showed good surgical outcomes, without a risk of hip displacement throughout the follow-up duration, while hip reconstructive surgery in the displaced hip was associated with a risk of increased hip displacement.

Background: Simultaneous motion of the knee and ankle joints is required for many activities including gait. We aimed to evaluate the influence of surgery involving tendons around the knee on ankle motion during gait in the sagittal plane in cerebral palsy patients., Methods: We included data from 55 limbs in 34 patients with spastic cerebral palsy. Patients were followed up after undergoing only distal hamstring lengthening with or without additional rectus femoris transfer. The patients' mean age at the time of knee surgery was 11.2 ± 4.7 years, and the mean follow-up duration was 2.2 ± 1.5 years (range, 0.9-6.0 years). Pre- and postoperative kinematic variables that were extracted from three-dimensional gait analyses were then compared to assess changes in ankle motion after knee surgery. Outcome measures included ankle dorsiflexion at initial contact, peak ankle dorsiflexion during stance, peak ankle dorsiflexion during swing, and dynamic range of motion of the ankle. Various sagittal plane knee kinematics were also measured and used to predict ankle kinematics. A linear mixed model was constructed to estimate changes in ankle motion after adjusting for multiple factors., Results: Improvement in total range of motion of the knee resulted in improved motion of the ankle joint. We estimated that after knee surgery, ankle dorsiflexion at initial contact, peak ankle dorsiflexion during stance, peak ankle dorsiflexion during swing, and dynamic range of motion of the ankle decreased, respectively, by 0.4° (p = 0.016), 0.6° (p < 0.001), 0.2° (p = 0.038), and 0.5° (p = 0.006) per degree increase in total range of motion of the knee after either knee surgery. Furthermore, dynamic range of motion of the ankle increased by 0.4° per degree increase in postoperative peak knee flexion during swing., Conclusions: Improvement in total knee range of motion was found to be correlated with improvement in ankle kinematics after surgery involving tendons around the knee. As motion of the knee and ankle joints is cross-linked, surgeons should be aware of potential changes in the ankle joint after knee surgery.

Objective: To assess differences in body composition according to gross motor function in children with cerebral palsy (CP) compared with healthy controls., Design: Retrospective case-control study., Setting: Tertiary referral center for CP., Participants: Participants (N=146) comprised consecutive patients with CP (n=100; mean age, 11.5±4.2y) who were admitted for orthopedic surgery between May 2014 and March 2016 and typically developing children (TDC, n=46; control group)., Interventions: Not applicable., Main Outcome Measures: Bioelectrical impedance analysis (BIA) was used to assess body composition, including body fat, soft lean mass (SLM), fat-free mass (FFM), skeletal muscle mass (SMM), body cell mass (BCM), bone mineral content (BMC), and basal metabolic rate. Body composition measures were compared according to Gross Motor Function Classification System (GMFCS) level, as well as between children with CP and TDC., Results: Children with CP with GMFCS levels IV and V had a lower height, weight, and body mass index than those with GMFCS levels I to III. Children with CP with GMFCS levels IV and V had a significantly lower SLM, SLM index, FFM, FFM index, SMM, SMM index, BCM, BCM index, BMC, and BMC index than those with GMFCS levels I to III and TDC. GMFCS level significantly affected SLM and BMC., Conclusions: Body composition analysis using BIA showed that nonambulatory children with CP had significantly lower FFM, SLM, SMM, BCM, and BMC than ambulatory children with CP and TDC. However, further study is required to allow the use of BIA as a valid nutritional assessment tool in patients with CP., (Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Background: Although several studies have investigated the outcomes after distal hamstring lengthening (DHL), no study has undertaken an approach that included all or most of the important factors that could influence the results. This study was performed to evaluate the outcomes after DHL and analyze the factors that influence the improvement and serial change in knee motion after surgery in patients with cerebral palsy (CP), using a linear mixed model (LMM)., Methods: The study included 314 ambulatory CP patients (594 limbs) with spsastic diplegia who were followed up after undergoing DHL as part of a single-event multilevel surgery and who underwent preoperative and postoperative 3-dimensional (3D) gait analyses. Relevant kinematic values, including knee flexion at initial contact, minimum knee flexion in the stance phase, knee range of motion (ROM), mean pelvic tilt and gait deviation index (GDI) score, were the outcome measures. Changes in knee motion and the GDI score were adjusted for multiple factors, such as sex, the Gross Motor Function Classification System (GMFCS) level, and concomitant surgeries as fixed effects, and follow-up duration, laterality, and each subject as random effects, using a LMM., Results: We found significant improvements in knee flexion at initial contact, minimum knee flexion in the stance phase, knee ROM, and GDI score 2 years after DHL. In patients with GMFCS level I and II, improvement in all sagittal knee kinematics was maintained during follow-up. In addition, GDI score, which represents overall gait pathology, consistently improved throughout the follow-up duration (1.2 per year, p = 0.008)., Conclusion: Medial hamstring lengthening with semitendinosus transfer, as a part of a SEMLS, was effective procedure in treating flexed knee gait with regard to sagittal knee kinematics and GDI score in spastic CP with flexed knee gait.

Aim: Acetabular dysplasia is the one of main causes of hip displacement in patients with cerebral palsy (CP). Although several studies have shown a relationship between hip displacement and acetabular dysplasia, relatively few have evaluated the association between quantitative acetabular dysplasia and related factors, such as Gross Motor Function Classification System (GMFCS) level., Method: We performed a morphometric analysis of the acetabulum in patients with CP using multiplanar reformation of computed tomography data. The three directional acetabular indices (anterosuperior, superolateral, and posterosuperior) were used to evaluate acetabular dysplasia. Consequently, linear mixed-effects models were used to adjust for related factors such as age, sex, GMFCS level, and migration percentage., Results: A total of 176 patients (mean age 9y 5mo, range 2y 4mo-19y 6mo; 104 males, 72 females) with CP and 55 typically developing individuals (mean age 13y 6mo, range 2y 5mo-19y 10mo; 37 males, 18 females) in a comparison group were enrolled in this study. Statistical modelling showed that all three directional acetabular indices independently increased with GMFCS level (p<0.001) and migration percentage (p<0.001)., Interpretation: Acetabular dysplasia was independently affected by both the amount of hip displacement and the GMFCS level. Thus, physicians should consider not only the migration percentage but also three-dimensional evaluation in patients at high GMFCS levels., (© 2017 Mac Keith Press.)

Aim: We aimed to evaluate the bone mineral density of the hip joint in patients with cerebral palsy (CP)., Method: Patients with CP younger than 18 years who underwent three-dimensional hip examination by computed tomography were analysed. Bone attenuation of the acetabulum and femur was measured as Hounsfield units (HU), and was adjusted for affecting factors such as hip instability and Gross Motor Function Classification System (GMFCS)., Results: One hundred and twenty-six patients with CP and 86 typically developing participants were included. The average bone attenuation was significantly lower in those with CP than in the comparison group (acetabulum: 70.8HU, 95% confidence interval [95% CI] 59.9-81.8; femur: 82.2HU, 95% CI 70.4-95.8). Compared with GMFCS levels I to III, bone attenuation was significantly lower for GMFCS levels IV (acetabulum: 30.9HU, 95% CI 15.7-46.2; femur: 39.7HU, 95% CI 19.9-59.5) and V (acetabulum: 51.7HU, 95% CI 35.9-67.5; femur: 72.5HU, 95% CI 51.9-93.0). The average bone attenuation decreased when the migration percentage was over 37% (acetabulum: 11.6HU, 95% CI 1.4-24.6; femur: 26.8HU, 95% CI 9.9-43.6)., Interpretation: Bone attenuation of the acetabulum and femur was significantly affected both by GMFCS level and by severity of hip instability., (© 2016 Mac Keith Press.)

Progression of hip displacement is common in patients with cerebral palsy (CP). We aimed to investigate the rate of progression of hip displacement in patients with CP by assessing changes in radiographic indices according to Gross Motor Function Classification System (GMFCS) level during hip surveillance. We analyzed the medical records of patients with CP aged < 20 years who underwent at least 6 months interval of serial hip radiographs before any surgical hip intervention, including reconstructive surgery. After panel consensus and reliability testing, radiographic measurements of migration percentage (MP), neck-shaft angle (NSA), acetabular index (AI), and pelvic obliquity (PO) were obtained during hip surveillance. For each GMFCS level, annual changes in radiographic indices were analyzed and adjusted for affecting factors, such as sex, laterality, and type of CP. A total of 197 patients were included in this study, and 1,097 radiographs were evaluated. GMFCS classifications were as follows: 100 patients were level I-III, 48 were level IV, and 49 were level V. MP increased significantly over the duration of hip surveillance in patients with GMFCS levels I-III, IV, and V by 0.3%/year (P < 0.001), 1.9%/year (P < 0.001), and 6.2%/year (P < 0.001), respectively. In patients with GMFCS level IV, NSA increased significantly by 3.4°/year (P < 0.001). Our results suggest that periodic monitoring and radiographic hip surveillance is warranted for patients with CP, especially those with GMFCS level IV or V. Furthermore, physicians can predict and inform parents or caregivers regarding the progression of hip displacement in patients with CP.

Purpose: We estimated the annual changes in radiographic indices of the spine in cerebral palsy (CP) patients and analyzed the factors that influence its progression rate., Methods: We included CP patients who had undergone whole-spine radiography more than twice and were followed for at least 1 year. The scoliosis Cobb angle, coronal balance, apical vertebral translation, apical rotation, and pelvic obliquity were measured on anteroposterior (AP) radiographs; thoracic kyphosis and lumbar lordosis angles, and sagittal balance was measured on lateral radiographs; and migration percentage was measured on AP hip radiographs to determine hip instability. For each gross motor function classification system (GMFCS) level, the Cobb angles, apical vertebral translation, coronal and sagittal balance, and pelvic obliquity were adjusted by multiple factors with a linear mixed model., Results: A total of 184 patients (774 radiographs) were included in this study. There was no significant annual change in scoliosis Cobb, thoracic kyphosis, and lumbar lordosis angles in the GMFCS level I-II and III groups. In the GMFCS level IV-V group, there was an annual increase of 3.4° in the scoliosis Cobb angle (p = 0.020). The thoracic kyphosis angle increased by 2.2° (p = 0.018) annually in the GMFCS level IV-V group. Apical vertebral translation increased by 5.4 mm (p = 0.029) annually in the GMFCS level IV-V group. Progression of coronal and sagittal balance and pelvic obliquity with aging were not statistically significant. Sex, hip instability, hip surgery, and triradiate cartilage did not affect the progression of scoliosis and the balance of the spine and pelvis., Conclusions: The scoliosis Cobb angle, thoracic kyphosis angle, and apical vertebral translation in the GMFCS level IV-V CP patients progressed with age. These findings can predict radiographic progression of scoliosis in CP patients.

This study investigated the radiologic results of a stepwise surgical approach to equinocavovarus in 24 patients with cerebral palsy and determined the extent to which each procedure affected radiographic parameters using a linear mixed model. The anteroposterior talus-first metatarsal and anteroposterior talonavicular coverage angles were improved. The calcaneal pitch angle, tibiocalcaneal angle, lateral talus-first metatarsal angle, and naviculocuboid overlap were also improved. The Dwyer sliding osteotomy affected the tibiocalcaneal angle, whereas first metatarsal dorsal wedge osteotomy improved the calcaneal pitch angle and lateral first metatarsal angle. The stepwise surgical approach is effective for correction of equinocavovarus in cerebral palsy patients.

Purpose: This study investigated the correlation between isometric muscle strength, gross motor function, and gait parameters in patients with spastic cerebral palsy and to find which muscle groups play an important role for gait pattern in a flexed knee gait., Materials and Methods: Twenty-four ambulatory patients (mean age, 10.0 years) with spastic cerebral palsy who were scheduled for single event multilevel surgery, including distal hamstring lengthening, were included. Preoperatively, peak isometric muscle strength was measured for the hip flexor, hip extensor, knee flexor, and knee extensor muscle groups using a handheld dynamometer, and three-dimensional (3D) gait analysis and gross motor function measure (GMFM) scoring were also performed. Correlations between peak isometric strength and GMFM, gait kinematics, and gait kinetics were analyzed., Results: Peak isometric muscle strength of all muscle groups was not related to the GMFM score and the gross motor function classification system level. Peak isometric strength of the hip extensor and knee extensor was significantly correlated with the mean pelvic tilt (r=-0.588, p=0.003 and r=-0.436, p=0.033) and maximum pelvic obliquity (r=-0.450, p=0.031 and r=-0.419, p=0.041). There were significant correlations between peak isometric strength of the knee extensor and peak knee extensor moment in early stance (r=0.467, p=0.021) and in terminal stance (r=0.416, p=0.043)., Conclusion: There is no correlation between muscle strength and gross motor function. However, this study showed that muscle strength, especially of the extensor muscle group of the hip and knee joints, might play a critical role in gait by stabilizing pelvic motion and decreasing energy consumption in a flexed knee gait.

Aim: The aim of this study was to clarify the method of the Duncan-Ely test and to estimate its interobserver reliability and validity by comparing it with three-dimensional gait analysis (3DGA)., Method: This study included 36 consecutive ambulatory patients with cerebral palsy (CP) who underwent preoperative 3DGA. The Duncan-Ely test was performed during three different velocities (slow, gravity, and fast). The interobserver reliability was assessed by three examiners. The results of the test were compared with kinematic variables derived from the gait analysis to assess the sensitivity and specificity of the test. The cut-off value was determined at the point of trade-off between the highest sensitivity and specificity., Results: The intraclass correlation coefficient measuring interobserver reliability of the Duncan-Ely test was greatest during fast velocity (0.819). The sensitivity and specificity of the test during gravity velocity for knee range of motion total were 63.0% and 100% respectively, with a cut-off value of 78.3°. The sensitivity and specificity of the test during fast velocity for knee range of motion total were 66.7% and 100% respectively, with a cut-off value of 65°., Interpretation: The Duncan-Ely test shows excellent reliability in fast knee-flexion velocity, and good sensitivity and specificity compared with 3DGA during physical examination as a preoperative assessment of rectus femoris spasticity in patients with CP., (© 2015 Mac Keith Press.)

Background: Recurrence of equinus deformity after surgery is common in patients with cerebral palsy. This retrospective study was undertaken to estimate the recurrence rate of the equinus deformity after tendo-Achilles lengthening (TAL) in patients with cerebral palsy and to investigate the risk factors associated with the recurrence., Methods: Two-hundred forty three ambulatory patients with cerebral palsy, who underwent TAL for equinus foot deformity since 1995, and had undergone a preoperative and postoperative 3-dimensional gait analysis, were included. Cox proportional hazards model was used to determine the significant contributing factor for the recurrence of equinus foot deformity., Results: The mean patient age at surgery was 7.8±2.7 years and the mean follow-up duration was 8.1±3.4 years. Equinus deformity recurred in 22 of the 243 patients (9.1%) and the Kaplan-Meier survival estimate was shown to be 89.4% at 10 years not needing repeat surgery. According to the multivariate analysis using the Cox proportional hazard model, preoperative ankle dorsiflexion at initial contact (P=0.016) was the only significant factor for recurrence of equinus deformity after surgery. Age at surgery and the type of limb involvement were not associated with the recurrence (P=0.433 and 0.269). The cutoff values of preoperative gait kinematics between the nonrecurrence and recurrence groups were -19 degrees of ankle dorsiflexion at initial contact (P=0.018)., Conclusions: This study showed that the severity of preoperative equinus deformity was a risk factor associated with recurrence after TAL in patients with cerebral palsy. Therefore, surgeons should consider the recurrence and later revision surgery for the patients with severe equinus foot deformity., Level of Evidence: Therapeutic level III.

Because complications are more common in patients with cerebral palsy (CP), surgeons and anesthesiologists must be aware of perioperative morbidity and be prepared to recognize and treat perioperative complications. This study aimed to determine the incidence of and risk factors for perioperative complications of orthopedic surgery on the lower extremities in patients with CP. We reviewed the medical records of consecutive CP patients undergoing orthopedic surgery. Medical history, anesthesia emergence time, intraoperative body temperature, heart rate, blood pressure, immediate postoperative complications, Gross Motor Function Classification System (GMFCS) level, Cormack-Lehane classification, and American Society of Anesthesiologists physical status classification were analyzed. A total of 868 patients was included. Mean age at first surgery was 11.8 (7.6) yr. The incidences of intraoperative hypothermia, absolute hypotension, and absolute bradycardia were 26.2%, 4.4%, and 20.0%, respectively. Twenty (2.3%) patients had major complications, and 35 (4.0%) patients had minor complications postoperatively. The incidences of intraoperative hypothermia, absolute hypotension, and major postoperative complications were significantly higher in patients at GMFCS levels IV and V compared with patients at GMFCS levels I to III (P<0.001). History of pneumonia was associated with intraoperative absolute hypotension and major postoperative complications (P<0.001). These results revealed that GMFCS level, patient age, hip reconstructive surgery, and history of pneumonia are associated with adverse effects on intraoperative body temperature, the cardiovascular system, and immediate postoperative complications.

Purpose: The aim of this study was to translate and transculturally adapt the Caregiver Priorities & Child Health Index of Life with Disabilities (CPCHILD) questionnaire into Korean language, and to test the reliability and validity, including the internal consistency, known-group validity and factor analysis of the Korean version of the CPCHILD., Methods: A Korean version of CPCHILD was produced according to internationally accepted guidelines. For validity testing, 194 consecutive parents or caregivers of children with cerebral palsy (CP) were recruited and completed the questionnaire. Internal consistency, test-retest reliability, and known-groups validity were evaluated and factor analysis was performed to validate the Korean version of the CPCHILD., Results: In terms of internal consistency, a Cronbach's alpha was above 0.90 in all domains of the CPCHILD (range 0.921 to 0.966), except the 5th domain (0.628). In terms of known-groups validity, the total score of the CPCHILD was significantly different according to the Gross Motor Function Classification System (GMFCS) level (p < 0.001). Intra-class correlation coefficient spanned from 0.517 to 0.801. Factor analysis showed that the five-factor solution of the CPCHILD explained 76.7% of the variance with 59.0, 6.5, 5.1, 4.2 and 3.2% of variance by each components number., Conclusions: The Korean version of CPCHILD was found to be a reliable and valid questionnaire of caregivers' perspectives on the health-related quality of life in severely affected children with CP. However, the Korean version of CPCHILD contains some redundant items, and factor analysis suggested a five-domain questionnaire. Implication for Rehabilitation The Korean version of CPCHILD is a reliable, internally consistent, valid instrument for assessing the health-related quality of life in severely affected children with CP from the perspective of caregivers. After the transcultural adaptation and validation of the Korean CPCHILD, it can be reliably used in clinical and research settings to evaluate the health-related quality of life in Korean patients with CP.

Background: The aim of this study was to identify the risk factors for anterior knee pain in patients with cerebral palsy., Methods: This prospective study investigated the risk factors for anterior knee pain in 127 ambulatory patients with spastic cerebral palsy in terms of walking pain, resting pain, and provocative pain. Demographic data analysis and physical examination for measuring the knee flexion contracture and unilateral and bilateral popliteal angles were performed. Patellar height was measured on radiographs, and patella alta was identified. The risk factors for anterior knee pain were analyzed using multivariate analysis with a generalized estimating equation., Results: Seventy-seven patients were found to have patella alta based on the radiographic measurements (60.6%). Overall, sixteen patients (12.6%) had either unilateral or bilateral anterior knee pain. Of these, 6 patients showed a visual analogue scale (VAS) ≤ 3, 9 patients showed 3 < VAS ≤ 7, and one patient showed a VAS > 7. Age was found to be a significant risk factor for walking pain and resting pain with odds ratios (ORs) of 1.08 (95% confidence interval [CI], 1.02 to 1.14) and 1.09 (95% CI, 1.03 to 1.15), respectively. In the multivariate analysis, knee flexion contracture was a significant protective factor with an OR of 0.92 (95% CI, 0.85 to 0.98)., Conclusions: Approximately 12.6% of ambulatory patients with spastic cerebral palsy were found to have anterior knee pain in our hospital-based cohort study. Age was found to be a significant risk factor for anterior knee pain while walking and resting.

Background: Hip instability can cause major problems in children with cerebral palsy, although good outcomes of hip reconstructive surgery for hip instability have been reported. In the present study, we investigated the recurrence of hip instability after reconstructive surgery and the factors influencing this recurrence in patients with cerebral palsy., Methods: We examined consecutive patients with hip instability related to cerebral palsy who had undergone hip reconstructive surgery including femoral varus derotational osteotomy. The neck-shaft angle, head-shaft angle, and migration percentage were measured at each postoperative follow-up evaluation. For each Gross Motor Function Classification System (GMFCS) level, annual changes in radiographic indices were adjusted for multiple factors with use of a linear mixed model, with sex as the fixed effect and laterality and each subject as the random effects., Results: A total of 144 hips (seventy-six patients) were included in this study, and 845 radiographs were evaluated. The GMFCS level was II or III for twelve patients, IV for thirty, and V for thirty-four. The neck-shaft angle showed no significant change in the patients with GMFCS level II or III (p = 0.425), IV (p = 0.106), or V (p = 0.972). The head-shaft angle showed a significant change in those with GMFCS level IV (p = 0.008) but not in those with level II or III (p = 0.201) or V (p = 0.591). The migration percentage did not change significantly in patients with GMFCS level II or III (p = 0.742), but it increased significantly by 2.0% per year (p < 0.001) in patients with GMFCS level IV and by 3.5% per year (p = 0.003) in those with level V., Conclusions: Periodic monitoring and follow-up for the recurrence of hip instability is important in patients with cerebral palsy and a GMFCS level of IV or V., (Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: Although several studies have reported on the outcomes of rectus femoris transfer (RFT), few have investigated the multiple factors that could affect the results. Therefore, we evaluated the outcomes of RFT and analyzed factors that influence improvement and annual change in knee motion after surgery in patients with cerebral palsy (CP)., Methods: We reviewed ambulatory patients with CP who were followed up after they had undergone RFT as part of a single-event multilevel surgery (SEMLS) and who had undergone preoperative and postoperative three-dimensional (3D) gait analysis between January 1995 and December 2012. Relevant kinematic values, including peak knee flexion, knee range of motion, and timing of peak knee flexion in the swing phase and gait deviation index (GDI) score, were the outcome measures. Improvements in rate of angle and GDI score were adjusted by multiple factors such as sex, Gross Motor Function Classification System (GMFCS) level, anatomic type of CP, and concomitant surgeries as the fixed effects, and follow-up duration, laterality, and each subject as the random effects, all of which was performed using a linear mixed model., Results: A total of 290 patients (487 limbs) and 612 3D gait analysis (2-4 per patient) results were finally included in this study. At 2 years after RFT, estimated mean peak knee flexion (1.2°, p=0.005), estimated mean knee range of motion (10.7°, p<0.001), and estimated mean GDI score (7.3, p<0.001) increased significantly. Peak knee flexion in the swing phase occurred 5.4% earlier after surgery compared with that at baseline (p<0.001). In serial postoperative gait analyses, peak knee flexion in the swing phase occurred 0.8% earlier per year in patients with GMFCS level I or II (p=0.021)., Conclusions: RFT as part of a SEMLS was effective in treating stiff knee gait. In serial postoperative gait analyses, patients with GMFCS level I or II showed better prognosis than those with level III with regard to timing of peak knee flexion in the swing phase., Level of Evidence: Prognostic level IV., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: The efficacy of using botulinum toxin A injections in cerebral palsy (CP) is controversial. The financial conflict of interest related to medical research can affect the conclusion of an evidence-based review. This study was performed to determine as to what proportion of studies on botulinum toxin A injections in patients with CP was sponsored by the industry and whether the assessments of botulinum toxin injection in CP were associated with industry support., Methods: Studies were identified with a search of the PubMed database (January 1991 to November 2011). All prospective, comparative, English language studies on the use of botulinum toxin A injections in patients with CP were included. A total of 374 articles were screened, 128 potentially eligible full articles were retrieved, and 66 studies met our inclusion criteria. The funding sources of the articles were reviewed, and qualitative conclusions regarding the effect of botulinum toxin A injection were classified as being either favorable, neutral, or unfavorable., Results: Of 66 eligible articles, 28 were funded by the industry, and 25 were not. The other 13 studies did not include information on the funding source. A significant association was observed between the funding source and qualitative conclusions (P=0.042). Fifteen (53.6%) of the 28 industry-sponsored studies had favorable conclusions, whereas only 5 (20%) of the 25 non-industry-sponsored studies had favorable conclusions., Conclusions: About half of studies on the effect of botulinum toxin A in CP were sponsored by the industry. This systematic review revealed that the qualitative conclusions in those studies are more favorable to the use of the botulinum toxin A than the non-industry-sponsored studies. Clinicians should be aware of an industry-related conflict of interest regarding reports on the efficacy of botulinum toxin A injections in patients with CP., Level of Evidence: Level II-therapeutic study.

Background: The relationship between torsional bony deformities and rotational gait parameters has not been sufficiently investigated. This study was to investigate the degree of contribution of torsional bony deformities to rotational gait parameters in patients with diplegic cerebral palsy (CP)., Methods: Thirty three legs from 33 consecutive ambulatory patients (average age 9.5 years, SD 6.9 years; 20 males and 13 females) with diplegic CP who underwent preoperative three dimensional gait analysis, foot radiographs, and computed tomography (CT) were included. Adjusted foot progression angle (FPA) was retrieved from gait analysis by correcting pelvic rotation from conventional FPA, which represented the rotational gait deviation of the lower extremity from the tip of the femoral head to the foot. Correlations between rotational gait parameters (FPA, adjusted FPA, average pelvic rotation, average hip rotation, and average knee rotation) and radiologic measurements (acetabular version, femoral anteversion, knee torsion, tibial torsion, and anteroposteriortalo-first metatarsal angle) were analyzed. Multiple regression analysis was performed to identify significant contributing radiographic measurements to adjusted FPA., Results: Adjusted FPA was significantly correlated with FPA (r=0.837, p<0.001), contralateral FPA (r=0.492, p=0.004), pelvic rotation during gait (r=-0.489, p=0.004), knee rotation during gait (r=0.376, p=0.031), and femoral anteversion (r=0.350, p=0.046). In multiple regression analysis, femoral anteversion (p=0.026) and tibial torsion (p=0.034) were found to be the significant contributing structural deformities to the adjusted FPA (R2=0.247)., Conclusions: Femoral anteversion and tibial torsion were found to be the significant structural deformities that could affect adjusted FPA in patients with diplegic CP. Femoral anteversion and tibial torsion could explain only 24.7% of adjusted FPA.

Background: Calcaneal lengthening has been used to correct planovalgus foot deformities in patients with cerebral palsy (CP)., Questions/purposes: This study was performed to investigate the amount of correction that can be achieved after calcaneal lengthening for the treatment of a planovalgus deformity in patients with CP and to provide cutoff values based on the preoperative radiographic measurements that suggest additional procedures to achieve satisfactory correction., Methods: Seventy-five consecutive patients with CP who underwent calcaneal lengthening for planovalgus deformity were included. Radiographic indices were measured on preoperative and latest followup weightbearing foot radiographs. The cutoff values of the preoperative radiographic measurements between the corrected and undercorrected groups were analyzed. The cutoff values are the reference values that can judge the possibilities of sufficient correction of a planovalgus deformity by calcaneal lengthening., Results: The mean age of the patients at the time of surgery was 11.0 ± 5.2 years and the minimum followup was 1.0 years (mean, 3.1 ± 2.2 years; range, 1.0-8.4 years). AP talus-first metatarsal angle, calcaneal pitch angle, talocalcaneal angle, lateral talus-first metatarsal angle, and naviculocuboid overlap showed major improvements after calcaneal lengthening. The cutoff values of preoperative measurements between the corrected and undercorrected groups were 23° AP talus-first metatarsal angle, 36° lateral talus-first metatarsal angle, and 72% naviculocuboid overlap., Conclusions: Calcaneal lengthening with concomitant peroneus brevis lengthening is an effective procedure for correcting a planovalgus foot deformity in patients with CP. However, for patients with greater than 23° AP talus-first metatarsal angle, 36° lateral talus-first metatarsal angle, and 72% naviculocuboid overlap, additional procedures for medial stabilization, such as tibialis posterior tendon reefing and talonavicular arthrodesis, should be considered as a result of the possibility of undercorrection with calcaneal lengthening alone.

The aim of this retrospective study was to determine the short-term effects of proximal femoral derotation osteotomy (FDO) on gait in 53 ambulatory patients with spastic diplegia controlling all confounding procedures. All patients showed a jump gait pattern and had undergone bilateral rectus femoris transfer, distal hamstring lengthening, and tendo-Achilles lengthening as a single-event multilevel surgery. Of these, additional bilateral proximal FDOs were included in 25 patients, defined as the FDO group; the other 28 patients were defined as the no-FDO group. Kinematic variables, such as pelvic tilt, minimal hip flexion in stance, hip rotation, and foot progression angle, were compared between the two groups at postoperative 1 year. Hip extension, hip rotation, and hip adduction improved significantly after surgery in the FDO group (P<0.001, P=0.004, P=0.028), but not in the no-FDO group. Foot progression angle improved in both groups, but the degree of improvement was significantly greater in the FDO group (P=0.004). In conclusion, FDO improved hip rotation, hip adduction, and hip extension as well as foot progression angle in the ambulatory patients with spastic diplegia showing a jump gait.

Distal hamstring lengthening (DHL) is a commonly performed procedure in flexed knee gait. However, the necessity of this procedure has been challenged due to the concerns on adverse effects in long-term follow-up. This retrospective study was undertaken to investigate the long-term outcome of single event multilevel surgery (SEMLS), including bilateral DHL, in ambulatory patients with cerebral palsy using 3D gait analysis. Twenty-nine ambulatory patients with spastic diplegic cerebral palsy who had undergone SEMLS including bilateral DHL were included. 3D gait analysis was performed preoperatively, 1 year postoperatively and over 10 years postoperatively. Preoperative temporal parameters, kinematics and GDI were compared with values obtained 1 and 10 year follow-up visits. The mean age of patients at time of first surgery was 8.3 years (range, 5.4-16.3 years), and mean time from first surgery to last 3D gait analysis was 11.8 years (range, 10.0-13.3 years). Mean pelvic tilt was not changed significantly after SEMLS including DHL. Mean knee flexion at initial contact decreased from 31.1° preoperatively to 26.0° at 1 year postoperatively (p=0.065), and then decreased significantly to 23.6° at 10 years postoperatively (p=0.038) versus the preoperative value. Mean GDI score significantly improved from 69.4 preoperatively to 77.9 at 1 year postoperatively (p=0.003) and continuously improved to 82.2 at 10 years postoperatively (p=0.017). Single event multilevel surgery including DHL provides a favorable outcome 10 years postoperatively in patients with spastic diplegic cerebral palsy., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Background: Previous studies have shown that hamstring lengths are often not short in patients with cerebral palsy, which raises concerns over the benefits of distal hamstring lengthening in patients with crouch gait. In this study, the authors measured lengths of hamstrings and psoas muscles in normal subjects mimicking crouch gait and compared these with lengths in cerebral palsy patients with crouch gait., Methods: Thirty-six patients with cerebral palsy and crouch gait were included in this study, and in addition, 36 age- and sex-matched normal controls were recruited. Hamstring and psoas muscle lengths in patients were evaluated using gait analysis and interactive musculoskeletal modeling software. Muscle lengths were also measured in the normal control group during normal gait and while mimicking crouch gait, and these were compared with those of cerebral palsy patient with crouch gait., Results: No significant differences were observed between maximum hamstring (p=0.810) and maximum psoas (p=0.456) lengths of patients and controls mimicking crouch gait. However, patients showed significantly shorter excursions of hamstring (p=0.022) and psoas (p=0.036) muscles than controls, whereas no significant excursion differences were observed between controls during normal gait and mimicking crouch gait., Conclusions: Normal controls mimicking crouch gait and cerebral palsy patients with crouch gait demonstrate similar muscle length patterns. However, mimicked crouch gait did not reproduce the excursion pattern shown by patients with crouch gait, which suggests that reduced hamstring and psoas excursion is an innate characteristic of pathologic crouch gait.

This study was carried out to determine parenting stress levels in the parents of children with cerebral palsy (CP) and to examine the factors that contribute to the parenting stress score. Parenting stress levels were assessed in 101 parents of children with CP (mean age 8.8 years, SD 2.1) using the parenting stress index (PSI). The extent of involvement, gross motor function classification system, and pediatric outcomes data collection instrument were collected for patients' information. The responding parent, parents' age, percentage of involvement in the parenting role, employment, socioeconomic status, educational level, other children, and age were obtained for parents' information. Normative percentile scores were calculated for each subscale, each domain, and the total PSI score. Multiple regression analysis was carried out to determine the significant factors contributing to the PSI score. The mean total PSI score was 97.7 (SD 4.6). The global function score of pediatric outcomes data collection instrument (P=0.004) and ambulatory states (gross motor function classification system, P=0.002) were found to be the significant factors contributing to the total PSI score, where parents of children with a more favorable function showed a higher PSI score. Parents of children with CP showed a high level of parenting stress. Clinicians should keep in mind that psychological support and intervention might be needed for parents of children with CP.

Background: The pediatric outcomes data collection instrument (PODCI) was originally developed to carry out a functional assessment of children and adolescents (including patients with cerebral palsy), focusing on musculoskeletal health. Validated questionnaires are important for assessing the functional outcome of cerebral palsy, and are meant to have unidimensionality, proper item gap, no ceiling and floor effects, and no item redundancy. The advances in health measurements have led to the application of Rasch analysis to assess questionnaires. This study evaluated PODCI in patients with cerebral palsy using Rasch analyses., Methods: The study included a total of 720 patients with gross motor function classification system level I to III, 192 with unilateral involvement and 528 with bilateral involvement. Rasch analysis was performed to obtain information on (1) the information weight fit statistic to assess the unidimensionality and redundancy of the items in each domain; (2) average item calibration to detect the item separation; and (3) item map to evaluate the ceiling and floor effects., Results: The PODCI worked best in the sports/physical function domain. In information weight fit statistics, there were 4 items violating unidimensionality, which included "putting on his/her coat" in transfer/basic mobility and "getting together and do things with friends" in sports/physical function. There were 4 items with item redundancy. Inadequate item separation was observed in the transfer/basic mobility domain. A ceiling effect was found in all domains, except for the sports/physical function., Conclusions: The sports/physical function domain in PODCI generally satisfies the requirements of Rasch item response theory and is an appropriate measure of the function in cerebral palsy. Although some individual items do not fit well, the PODCI can be improved by eliminating the redundant items and by adding more difficult tasks to fill in the gaps., Level of Evidence: Level II.

Aim: This study was undertaken to determine the need for concurrent prophylactic femoral varization osteotomy (FVO) of contralateral stable hips at the time of hip reconstructive surgery on unstable hips in non-ambulant individuals with cerebral palsy (Gross Motor Function Classification System levels IV and V)., Method: A decision analysis model was constructed that included (1) the probability of unstable hips during observation of the contralateral stable hips, (2) unstable hip rate (subluxation or dislocation rate) after prophylactic FVO or after delayed reconstructive surgery (including FVO) for unstable hips, and (3) complication rates after concurrent prophylactic FVO or after hip reconstructive surgery. The final outcome score was based on pain utility measures. The probabilities of all cases and the utility score were obtained by literature review., Results: The decision model favoured concurrent prophylactic FVO for the contralateral stable hips over observation (pain utility measure scores 0.814 vs 0.781). In a one-way sensitivity analysis, the decision model favoured concurrent prophylactic FVO when the unstable hip rate of contralateral stable hips during observation was 27% or over. Concurrent prophylactic surgery also demonstrated higher utility scores than observation when the unstable hip rate after FVO was between 0% and 29%., Interpretation: The decision analysis model demonstrated that concurrent prophylactic FVO for a contralateral stable hip in individuals with cerebral palsy undergoing hip reconstructive surgery was beneficial from a medical perspective, which was based on current evidence., (© The Authors. Developmental Medicine & Child Neurology © 2012 Mac Keith Press.)

Purpose: To investigate the prevalence and clinical features of ocular abnormalities in patients with cerebral palsy (CP) and the association with gross motor function., Methods: A complete ophthalmologic examination was performed in 88 consecutive patients with CP before and during orthopedic surgery in a tertiary hospital from July 2008 to March 2010. The prevalence and clinical features of ocular abnormalities and the association with gross motor function state were investigated., Results: Seventy-eight patients (89%) had ocular abnormalities. Refractive errors were found in 53 patients (60%). Strabismus including exotropia (50%), esotropia (9%), and hypertropia (9.1%) was found in 52 patients (59%). Posterior segment abnormalities were found in 19 patients (22%), cornea and lens abnormalities in 8 patients (9%), and epiblepharon in 5 patients (6%). Among 57 patients whose visual acuity could be measured, best-corrected visual acuity of the better eye was ≤ 20/40 in 18 patients (32%) and ≤ 20/200 in 3 patients (5%). Objective vision-impairing ocular abnormalities and vertical strabismus were significantly associated with poor gross motor function before orthopedic surgery., Conclusions: Ocular abnormalities were present in the majority of CP patients and patients with poor gross motor function were more likely to be afflicted with vision-impairing ocular abnormalities. Ophthalmologic evaluation is deemed necessary in CP patients, especially in those with poor motor function.

Background: There is a worldwide tendency of an increasing prevalence of obesity. Therefore, this study aimed at determining whether such a trend exists among cerebral palsy (CP) patients. We also tried to compare this trend with the trend in the general population. We also discuss the importance of obesity trends in CP patients., Methods: This retrospective study was performed on 766 ambulatory patients who were diagnosed with CP since 1996 in our institution. The associations among the prevalence of obesity and the body mass index, age, gender, the type of CP, the gross motor function classification system and the time of survey were investigated., Results: The overall prevalence of obesity was 5.7%, and the overall prevalence of obesity together with being overweight was 14.6% for the ambulatory patients with CP. The prevalence of obesity and of obesity together with being overweight did not show a statistically significant temporal increase. On the other hand, age and gender were found to affect the body mass index of the ambulatory CP patients (p < 0.001 and 0.003, respectively)., Conclusions: The extent of obesity and being overweight in the ambulatory patients with CP in this study was far less than that reported in the United States (US). In addition, it appears that the differences of the prevalence of obesity in children and adolescents between those with and without CP are disappearing in the US, whereas the differences of the prevalence of obesity in children and adolescents between those with and without CP seem to be becoming more obvious in Korea. Accordingly, care should be taken when adopting the data originating from the US because this data might be affected by the greater prevalence of obesity and the generally higher body mass indices of the US.

Objectives: This study examined the prevalence of cerebral palsy (CP) in South Korea, and the attributable lifetime medical cost according to physiological types and extent of involvement., Methods: The number of medical service use and medical cost of CP were obtained from the national health insurance review and assessment (HIRA) service. The prevalence was calculated from the number of five-year-old patients who used medical services between 2004 and 2008. The lifetime medical cost of CP was calculated from the data and discount rate of 3%., Results: The prevalence of CP in South Korea was 2.6 per 1000 children. The attributable lifetime medical cost of CP in South Korea was calculated to be 26,383 US dollars, which is 1.8 times the basic lifetime medical cost of the general population (14,579 US dollars). Spastic CP showed the highest attributable medical cost, followed by dyskinetic and ataxic CP. Spastic diplegia showed 1.4 times of the attributable lifetime medical cost of spastic hemiplegia., Conclusions: The prevalence of CP in South Korea is comparable to that in other countries. CP is a disease with wide range of clinical features, and the medical cost according to the physiological types and extent of involvement should be considered., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Background: Psoas contracture is known to cause abnormal hip motion in patients with cerebral palsy. The authors investigated the clinical relevance of hip kinematic and kinetic parameters, and 3D modeled psoas length in terms of discriminant validity, convergent validity, and responsiveness., Methods: Twenty-four patients with cerebral palsy (mean age 6.9 years) and 28 normal children (mean age 7.6 years) were included. Kinematic and kinetic data were obtained by three dimensional gait analysis, and psoas lengths were determined using a musculoskeletal modeling technique. Validity of the hip parameters were evaluated., Results: In discriminant validity, maximum psoas length (effect size r = 0.740), maximum pelvic tilt (0.710), maximum hip flexion in late swing (0.728), maximum hip extension in stance (0.743), and hip flexor index (0.792) showed favorable discriminant ability between the normal controls and the patients. In convergent validity, maximum psoas length was not significantly correlated with maximum hip extension in stance in control group whereas it was correlated with maximum hip extension in stance (r = -0.933, p < 0.001) in the patients group. In responsiveness, maximum pelvic tilt (p = 0.008), maximum hip extension in stance (p = 0.001), maximum psoas length (p < 0.001), and hip flexor index (p < 0.001) showed significant improvement post-operatively., Conclusions: Maximum pelvic tilt, maximum psoas length, hip flexor index, and maximum hip extension in stance were found to be clinically relevant parameters in evaluating hip flexor contracture.

Background: this study was undertaken to determine the validity and reliability of the physical examination tests commonly used to measure hip flexion contracture in patients with cerebral palsy who are able to walk., Methods: thirty-six consecutive patients (twenty-two male and fourteen female patients), with a mean age (and standard deviation) of 9.8 ± 3.9 years, who had cerebral palsy (level I, II, or III on the Gross Motor Function Classification System) and thirty-seven children without cerebral palsy (nineteen male and eighteen female subjects), with a mean age of 10.0 ± 3.0 years, were enrolled prospectively for this study. Hip flexion contracture was determined by three physical examination tests: the Thomas test, the prone hip extension test (the Staheli test), and the hamstring shift test. Three-dimensional gait analysis was performed in all subjects. The interobserver reliabilities of the three physical examination tests were determined with use of three observers. Convergent validity was assessed by evaluating the relationships between the findings on physical examination and kinematic and kinetic gait variables (maximum hip extension during stance and hip flexor index) and three-dimensional modeled psoas lengths., Results: the Thomas test showed the highest intraclass correlation coefficient (0.501 in patients and 0.207 in controls) and the smallest mean absolute difference (5.8° in patients and 1.2° in controls). The Staheli test was found to be the most valid method in the patient group (r = 0.568 with hip flexor index), whereas the Thomas test was the most valid in the control group (r = 0.526 with maximum hip extension in stance, and r = 0.532 with the hip flexor index). The hamstring shift test had the lowest intraclass correlation coefficient and the lowest convergent validity., Conclusions: while the Thomas test showed the highest intraclass correlation coefficient and the smallest mean absolute difference, the Staheli test was the most valid method for detecting hip flexion contractures in patients with cerebral palsy. Although the Staheli test cannot be used for intraoperative assessment, we recommend that this test be included in preoperative physical examinations to determine the role of a hip flexion contracture in the abnormal gait of patients with cerebral palsy.

Background: Translation and transcultural adaptation of the Pediatric Outcomes Data Collection Instrument (PODCI) into Korean language was performed, and the validity was tested., Methods: Korean version of PODCI was produced according to internationally accepted guideline, which included preparation, forward translation, reconciliation, back translation, review of back translation and harmonization, cognitive debriefing and review, and proof reading process. Eighty-two child controls (aged 5 to 10 y), 92 adolescent controls (aged 10 to 18 y), and 30 children with cerebral palsy (aged 5 to 10 y) undergoing single event multilevel surgery were included, and their parents also participated. Each subscale of Korean PODCI was tested in terms of internal consistency (Cronbach α), discriminant validity (difference of parental responses between child control and children with cerebral palsy), convergent validity (correlation between self-response and parental response in adolescent control), and responsiveness (postoperative changes of parental responses in children with cerebral palsy)., Results: All subscales except pain/comfort showed sufficient internal consistencies (Cronbach α > 0.7). Upper extremity/physical function, transfer/basic mobility, sports/physical functioning, and global functioning subscales showed significant discriminant validity (P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively). Correlation between self-response and parental response in adolescent controls were significant in all subscales, being highest in transfer/basic mobility subscale (r = 0.952, P < 0.001) and lowest in happiness subscale (r = 0.548, P < 0.001). Responsiveness was significant in transfer/basic mobility (P < 0.001), sports/physical functioning (P=0.001), and global functioning (P = 0.006) subscales after single event multilevel surgery., Conclusions: Korean version of PODCI showed relevant internal consistency, discriminant validity, convergent validity, and responsiveness except for pain/comfort and happiness subscales. Care need to be taken when evaluating subjective measures, such as pain/comfort and happiness subscales., Level of Evidence: Diagnostic level I.

Background: Proximal femoral deformity related to physis has not been studied in patients with cerebral palsy (CP). This study was performed to investigate the clinical relevance of neck shaft angle (NSA), head shaft angle (HSA), and proximal femoral epiphyseal shape in patients with CP, which represent the deformities of metaphysis, physis, and epiphysis, respectively., Methods: Three hundred eighty-four patients with CP (mean age 9.1 y, 249 males and 135 females) were included. Extent of involvement and functional states [Gross Motor Function Classification System (GMFCS) level] were obtained. Radiographic measurements including NSA, HSA, and qualitative shape of the proximal femoral epiphysis were evaluated and analyzed according to extent of involvement and GMFCS level. Reliability and correlation with each measurement were assessed. Multiple regression test was performed to examine the significant contributing factors to migration percentage (MP) that represents hip instability., Results: NSA showed excellent interobserver reliability with intraclass correlation coefficients of 0.976. Correlation with the MP was higher in the NSA (r=0.419, P<0.001) than in the HSA (r=0.256, P<0.001). NSA, HSA, and MP tended to increase with increasing GMFCS level, and proportion of valgus deformed proximal femoral epiphysis also increased with increasing GMFCS level, which means valgus deformity and unstable hips in the less favorable functional states. Multiple regression analysis revealed NSA, GMFCS level, and shape of the proximal femoral epiphysis to be significant factors affecting MP., Conclusions: NSA appeared to be more clinically relevant than HSA in evaluating proximal femoral deformity in patients with CP. Shape of proximal femoral epiphysis is believed to have clinical implications in terms of hip instability., Level of Evidence: Diagnostic level II.

Background: This study was performed to identify the issues of concern of parents of patients with cerebral palsy before single event multilevel surgery (SEMS)., Methods: The parental concerns of 64 patients [34 males, 30 females, mean age 15 y and 5 mo (SD 8 y and 10 mo)] with cerebral palsy were obtained using a questionnaire preoperatively. The issues of parental concern were evaluated using 59 items specifically designed for this study. The individual items were scored using a 5-point Likert scale (1 to 5)., Results: The top 5 issues of concern were as follows: postoperative rehabilitation, duration of rehabilitation, immediate postoperative pain, general anesthesia, and medical cost. Sporting activities and poor compliance to wearing orthosis were included in the top 5 issues of parental concern in patients with unilateral involvement. The overall parental concern in patients with unilateral involvement was lower than that in bilateral involvement (P=0.054). Parents of younger patients showed significantly higher concern score than those of older patients (P=0.020). There was no significant difference in the overall concern score between the parents of patients scheduled for bony procedures and those of patients scheduled for soft tissue procedures (P=0.298). Multiple regression analysis revealed the patient's age (P=0.018) and responding parent (father vs. mother, P=0.025) to be the factors that significantly affected the overall concern score (adjusted R(2)=0.281)., Conclusions: An understanding of the issues of concern will enhance communication between physicians and parents, which would assist in preoperative discussion., Level of Evidence: Diagnostic level II.

Background: This study was performed to determine changes in Pediatric Outcomes Data Collection Instrument (PODCI) scores after single-event multilevel surgery (SEMS), and to evaluate the relationship between the improvements of PODCI scores and parental satisfaction after SEMS., Methods: Demographic data, preoperative and postoperative PODCI, functional assessment questionnaire (FAQ) walking scales, and self-reported parental satisfaction with SEMS were obtained from 61 parents of ambulatory patients with cerebral palsy [40 male, 21 female, mean age 10 y 2 mo (SD 3 y 8 mo), mean follow-up 2 y 2 mo]. Postoperative improvements in each subscale of PODCI and FAQ were analyzed, and multiple regression analysis was performed to identify the factors that contributed significantly to postoperative parental satisfaction. Rasch analysis was performed for the PODCI subscale that was clinically relevant., Results: FAQ, transfers/basic mobility, sports/physical activity, and global function subscales of PODCI significantly improved after SEMS. Age, gross motor function classification system level, and the amount of improvement in sports/physical activity subscale were found to affect parental satisfaction to SEMS significantly. However, the subscale showed insufficient item responses, and ceiling and floor effects., Conclusions: Although changes in sports/physical activity subscale were relatively small, they were found to affect parental satisfaction with SEMS significantly. These indicate that clinicians and researchers should pay attention to sports and physical activities in patients with cerebral palsy., Level of Evidence: Diagnostic level I.

Background: Increased femoral anteversion and coxa valga are common in patients with cerebral palsy. The purpose of the present study was to determine the validity and reliability of the methods that are commonly used to measure the proximal femoral geometry in patients with cerebral palsy., Methods: Thirty-six consecutive patients (mean age, eleven years; range, five to twenty years) with cerebral palsy were enrolled in the present study. The validity and the interobserver reliability of the physical examinations performed by three examiners were determined by comparing the results of a trochanteric prominence angle test, hip internal rotation measurements, and hip external rotation measurements (all with the patient in the prone position) with the amount of femoral anteversion on two-dimensional computed tomography. Validity and intraobserver and interobserver reliability were assessed by comparing the neck-shaft angle on the anteroposterior internal rotation radiograph of the hips with that on the multiplanar reformatted computed tomographic image., Results: The trochanteric prominence angle test showed excellent concurrent validity (R = 0.862, p < 0.001) and reliability (intraclass correlation coefficient, 0.809). Hip internal rotation also showed good concurrent validity (R = 0.787, p < 0.001) and excellent reliability (intraclass correlation coefficient, 0.889), whereas hip external rotation appeared to be unsuitable for predicting femoral anteversion. The neck-shaft angle on the anteroposterior internal rotation radiograph of the hips showed excellent concurrent validity (R = 0.892, p < 0.001) and reliability (intraclass correlation coefficient, 0.912)., Conclusions: A physical examination for determining femoral anteversion and the neck-shaft angle as measured on the internal rotation radiograph of the hips appear to be clinically relevant methods for evaluating the proximal femoral geometry and version in patients with cerebral palsy. Computed tomographic examination can probably be replaced by physical examination and an anteroposterior internal rotation radiograph of the hips for patients with stable hips who are able to walk.