Search

Determining the presence and severity of knee osteoarthritis (OA) is a valuable application of inertial measurement units (IMUs) in the remote monitoring of patients. This study aimed to employ the Fourier representation of IMU signals to differentiate between individuals with and without knee OA. We included 27 patients with unilateral knee osteoarthritis (15 females) and 18 healthy controls (11 females). Gait acceleration signals were recorded during overground walking. We obtained the frequency features of the signals using the Fourier transform. The logistic LASSO regression was employed on the frequency domain features as well as the participant's age, sex, and BMI to distinguish between the acceleration data from individuals with and without knee OA. The model's accuracy was estimated by 10-fold cross-validation. The frequency contents of the signals were different between the two groups. The average accuracy of the classification model using the frequency features was 0.91 ± 0.01. The distribution of the selected features in the final model differed between patients with different severity of knee OA. In this study, we demonstrated that using logistic LASSO regression on the Fourier representation of acceleration signals can accurately determine the presence of knee OA. Determining the presence and severity of knee osteoarthritis (OA) is a valuable application of inertial measurement units (IMUs) in the remote monitoring of patients. This study aimed to employ the Fourier representation of IMU signals to differentiate between individuals with and without knee OA. We included 27 patients with unilateral knee osteoarthritis (15 females) and 18 healthy controls (11 females). Gait acceleration signals were recorded during overground walking. We obtained the frequency features of the signals using the Fourier transform. The logistic LASSO regression was employed on the frequency domain features as well as the participant’s age, sex, and BMI to distinguish between the acceleration data from individuals with and without knee OA. The model’s accuracy was estimated by 10-fold cross-validation. The frequency contents of the signals were different between the two groups. The average accuracy of the classification model using the frequency features was 0.91 ± 0.01. The distribution of the selected features in the final model differed between patients with different severity of knee OA. In this study, we demonstrated that using logistic LASSO regression on the Fourier representation of acceleration signals can accurately determine the presence of knee OA.

Background and purpose - Since the introduction of intramedullary bone transport nails only very few cases have been reported in the literature. Thus we evaluated the results and complications in a single institution retrospective cohort.Patients and methods - 15 (median age 40 years (18-70), 8 males) consecutive patients, were included and the electronic patient records and radiographs were reviewed. Complications were severity graded and categorized as device or non-device related.Results - The segmental bone loss was due to non-union site in 8 femurs and 4 tibias, or traumatic bone loss in 2 femurs and 1 tibia. The segmental bone defect was a median of 3 cm (0.5-10). 9 of 10 femoral cases and 4 of 5 tibial cases healed with the bone transport nail. All 15 patients had a healed docking site and regenerate at the end of treatment after a median of 13 months (6-38). 24 complications (15 device related and 9 non-device related) occurred in 11/15 patients with a minimum follow-up of 6 months after nail removal. The number of unplanned surgeries due to device related complications was: 0 in 9 patients, 1 in 3 patients, 2 in 1 patient, 3 in 2 patients.Interpretation - Segmental bone defects can heal with a bone transport nail. However, the number of complications was high and 15 out of 24 complications were devicerelated. Optimizing nail design is therefore needed to reduce complications in intramedullary bone transport.

Background and purpose — Pelvic radiographs are traditionally used for assessing femoral head migration in residual acetabular dysplasia (RAD). Knowledge of the heightened importance of cartilaginous structures in this condition has led to increased use of MRI in assessing both osseous and cartilaginous structures of the pediatric hip. Therefore, we assessed the relationship between migration percentages (MP) found on MRI and conventional radiographs. Second, we analyzed the reliability of MP in MRI and radiographs. Patients and methods — We retrospectively identified 16 patients (mean age 5 years [2–8], 14 girls), examined for RAD during a period of 2½ years. 4 raters performed blinded repeated measurements of osseous migration percentage (MP) and cartilaginous migration percentage (CMP) in MRI and radiographs. Pelvic rotation and tilt indices were measured in radiographs. Bland–Altman (B–A) plots and intraclass correlation coefficients (ICC) were calculated for agreement and reliability. Results — B–A plots for MPR and MPMRI produced a mean difference of 6.4 with limits of agreement –11 to 24, with higher disagreements at low average MP values. Mean MPR differed from mean MPMRI (17% versus 23%, p < 0.001). MPR had the best interrater reliability with an ICC of 0.92 (0.86–0.96), compared with MPMRI and CMP with ICC values of 0.61 (0.45–0.70) and 0.52 (0.26–0.69), respectively. Intrarater reliability for MPR, MPMRI and CMP all had ICC values above 0.75 and did not differ statistically significantly. Differences inMPMRI and MPR showed no correlation to pelvic rotation index, pelvic tilt index, or interval between radiograph and MRI exams. Interpretation — Pelvic radiographs underestimated MP when compared with pelvic MRI. We propose CMP as a new imaging measurement, and conclude that it has good intrarater reliability but moderate interrater reliability. Measurement of MP in radiographs and MRI had mediocre to excellent reliability.

PURPOSE: To translate and cross-culturally adapt the Challenge, and investigate the reliability and minimal detectable change (MDC) of the Danish Challenge in children with cerebral palsy (CP).MATERIALS AND METHODS: A Danish version of the Challenge was created through a standardized translation process. Four physiotherapists evaluated face validity. Independently ambulatory children with CP were tested. Live performance rating was conducted by assessors independently scoring the Challenge. Video-rating was undertaken for a subset of assessments. Same day assessment test-retest reliability was estimated. The Challenge's Best Score Total was of primary interest.RESULTS: Forty-five children (5-18 years: mean 10 years 9 months; 19 girls) in Gross Motor Function Classification System levels I and II were tested. Inter-rater reliability was excellent for live assessments (n = 45) ICC = 0.998 (95% CI 0.998-0.999) and video assessments (n = 15) ICC = 0.991 (95% CI 0.963-0.997) and intra-rater reliability was excellent for live versus video-recorded assessments (n = 10) ICC = 0.977 (95% CI 0.895-0.994). Test-retest reliability (n = 22) was excellent with ICC = 0.991 (95% CI 0.979-0.996) and minimal detectable change (MDC90) of 4.7 points.CONCLUSIONS: The Danish Challenge showed excellent reliability in this testing context when physiotherapists scored from live- or video-recorded assessments. The Challenge's ability to detect 4.7 points change seems a clinically realistic target for progress. Clinical trial registration: This trial has been approved by the Data Protection Agency, Central Region Denmark, Ref nr.: 615216, Case nr.: 1-16-02-46-16. Registration date: 01-01-2016.Implications for rehabilitationThe Challenge remained reliable and maintained a promising minimal detectable change of less than five points after translation and cultural adaptation.The Danish version of the Challenge 20-item version can be used to measure advanced motor skill performance in children with cerebral palsy, GMFCS level I and GMFCS level II.Challenge live scoring is as reliable as the more time-consuming video-recorded scoring, meaning that physiotherapists can choose the method that fits best with their clinical context and preference.

Aims Limb-lengthening nails have largely replaced external fixation in limb-lengthening and reconstructive surgery. However, the adverse events and high prevalence of radiological changes recently noted with the STRYDE lengthening nail have raised concerns about the use of internal lengthening nails. The aim of this study was to compare the prevalence of radiological bone abnormalities between STRYDE, PRECICE, and FITBONE nails prior to nail removal. Methods This was a retrospective case series from three centres. Patients were included if they had either of the three limb-lengthening nails (STYDE, PRECICE, or FITBONE) removed. Standard orthogonal radiographs immediately prior to nail removal were examined for bone abnormalities at the junction of the telescoping nail parts. Results In total, 306 patients (168 male, 138 female) had 366 limb-lengthening nails removed. The mean time from nail insertion to radiological evaluation was 434 days (36 to 3,015). Overall, 77% of STRYDE nails (20/26) had bone abnormalities at the interface compared with only 2% of FITBONE (4/242) and 1% of PRECICE nails (1/98; p < 0.001). Focal osteolysis in conjunction with periosteal reaction at the telescoping interface was only observed in STRYDE nails. Conclusion Bone abnormalities at the interface of telescoping nail parts were seen in the majority of STRYDE nails, but only very rarely with FITBONE or PRECICE nails. We conclude that the low prevalence of radiological changes at the junctional interface of 242 FITBONE and 98 PRECICE nails at the time of nail removal does not warrant clinical concerns. Cite this article: Bone Joint J 2021;103-B(11):1731–1735.

RigidTack™ is a newly developed implant for total temporary epiphyseodesis. The implant combines the technical advantages of the traditionally used rigid Blount-staples and the newer flexible eight-plates™. Thus, the implant is rigid like the Blount-staples, which may be a biomechanical advantage in temporary epiphyseodesis, and has an easy and guided implantation technique like the eight-plate™. As in eight-plates™, supposedly only two RigidTacks™ are sufficient for temporary epiphyseodesis compared to six Blount-staples in traditional treatment. The goal of this study was to compare Blount-staples and RigidTacks™ in regard to the total potential of growth arrest, the occurrence of postoperative implant-associated complications, secondary angular deformities, and central joint deformations. Twelve pigs were allocated in two groups (n = 6) for treatment of the proximal tibia. Total temporary epiphysiodesis was performed with either four Blount-staples or two RigidTacks™. Magnetic resonance imaging (MRI)-scans were performed before and 14 weeks after surgery, and the amount and distribution of growth arrest were evaluated by measuring the interphyseal distance in nine defined zones. Total temporary epiphysiodesis with two RigidTacks™ resulted in a similar amount of growth arrest as that of four Blount-staples. No significant coronal or sagittal angular deformities or joint deformities were observed in either group; however, one secondary loosening of a Blount-staple occurred. The study concluded that Blount-staples and RigidTacks™ are adequate implants for total temporary epiphysiodesis. Whether or not the precise implant-placement through the guided implantation technique of RigidTacks™ and a reduced number of implants indeed lead to a reduction of secondary angular deformities has to be investigated in further clinical trials. © 2019 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals, Inc. on behalf of Orthopaedic Research Society. J Orthop Res 38:946-953, 2020.

To translate and cross-culturally adapt theA Danish version of theForty-five children (5-18 years: mean 10 years 9 months; 19 girls) in Gross Motor Function Classification System levels I and II were tested. Inter-rater reliability was excellent for live assessments (The Danish

Introduction: Ludloff’s procedure for open reduction of congenital dislocation of the hip (CDH) is recommended for its minimal tissue damage, but is criticised for the risk of late avascular necrosis (AVN) of the femoral head. The aim of present study was primarily to assess the risk of late AVN of the femoral head and secondly the range of motion (ROM) of the hip and the quality of life in children following Ludloff’s procedure. Methods and materials: 13 hips in 11 children after Ludloff’s procedure due to CDH were included retrospectively from 1997 to 2005 at Aarhus University Hospital. Radiographs were evaluated for the presence of AVN of the femoral head and classified according to the Bucholz and Ogden classification, with type 2-4 having clinical relevance. A clinical examination included range of motion (ROM) and leg length discrepancy (LLD) measurements. The HAGOS hip questionnaire evaluated activity, participation and quality of life. Results: No severe type 3-4 AVN was observed. 2 type 2 and 5 type 1 were observed. AVN was observed in 7 of the 13 operated hips (54%). An 8.6° difference in flexion for unilaterally treated hips was observed (pConclusions: Only minor AVN of clinical importance was seen after Ludloff’s procedure.

Background and aims This prospective study aimed to assess pressure pain thresholds (PPTs) by pressure algometry and the correlation to postoperative pain in children undergoing orthopaedic surgery. We hypothesized, that the PPTs would decline immediately after elective orthopaedic surgery and return to baseline values at follow-up. Methods Thirty children aged 6–16 years were included. PPTs and intensity of pain (Numerical Rating Scale, NRS) were assessed 3–6 weeks before surgery (baseline), 1–2 h before surgery (Day 0), the first postoperative day (Day 1) and 6–12 weeks after surgery (Follow-up). Results A significant difference of PPTs between the four assessments was seen using the Friedman test for detecting differences across multiple tests and Wilcoxon signed-rank test with a Bonferroni adjustment. The changes in PPTs between baseline (PPTcrus = 248 kPa, PPTthenar = 195 kPa) and day 1 (PPTcrus = 146 kPa, PPTthenar = 161 kPa) showed a decline of PPTs as hypothesized (Zcrus = 2.373, p = 0.018; Zthenar = 0.55, p = 0.581). More surprisingly, a significant decrease in PPTs between baseline and day 0, just before surgery (PPTcrus = 171 kPa, PPTthenar = 179 kPa), was also measured (Zcrus = 2.475, p = 0.013; Zthenar = 2.414, p = 0.016). PPTs were positively correlated to higher age, weight and height; but not to NRS or opioid equivalent use. Conclusions Children undergoing orthopaedic surgery demonstrate significant changes in PPTs over time. The PPTs decrease significantly between baseline and day 0, further decreases the first day postoperatively and returns to baseline values at follow-up. This suggests that other factors than surgery modulate the threshold for pain. Implications Awareness of pressure pain thresholds may help identify children with affected pain perception and hence improve future pain management in children undergoing orthopaedic surgery. Factors as for example anticipatory anxiety, psychological habitus, expected pain, catastrophizing, distraction, physical activity, patient education and preoperative pain medication might play a role in the perception of pain and need further investigation.

Background and purpose - Current selective screening algorithms for developmental dysplasia of the hip (DDH) are insufficient. Universal screening programs have been proposed but so far have been deemed too expensive and time consuming. The pubo-femoral distance may solve this problem as a quick, low-cost, highly sensitive, and specific sonographic measurement for DDH, but this has only been validated in the supine position. Therefore we validated pubo-femoral distance (PFD) in the lateral position as an indicator for instability of the hip. Methods - All participants had undergone ultrasonographic diagnostics using the modified Graf technique. In addition, PFD measurements in lateral position were performed. Results were compared between 25 infants who had been treated for DDH because of dysplastic appearance on ultrasound combined with clinical instability and a control group consisting of 100 untreated infants screened for DDH. Sensitivity, specificity, and cut-off points were determined using Receiver operating characteristics (ROC) analysis. Results - We found a mean PFD of 6.8 mm (6.2-7.4) in the treated group with a control group PFD of 3.4 mm (3.3-3.6) (p < 0.005). A PFD value above a threshold of 4.4 mm yielded a sensitivity of 100% and a specificity of 93% for detecting unstable DDH. Interpretation - PFD measured in lateral position was statistically significantly increased in hips of children treated for DDH with Denis Browne hip brace compared with healthy children with unaffected stable hips. Furthermore, the PFD measurement had a high level of sensitivity and specificity at a cut-off value of 4.4 mm. A cut-off value of 6.00 mm has previously been reported as the gold standard in supine position. We suggest that 4.4 mm is used in lateral position.

Atypical femoral fractures (AFFs) are low-energy femoral fractures with characteristic radiological features and a suspected relation to treatment with bisphosphonate (BP) or denosumab. In osteogenesis imperfecta (OI), BP is currently the drug of choice when medical treatment is indicated. Due to bone deformities, the radiologic appearance of femoral fractures may be different in patients with OI and patients with osteoporosis. We investigated the prevalence and appearance of femoral fractures in a cohort of adult patients with confirmed OI (55 patients, age range 19-69 years, 26 women (47%) and 35 patients (64%) had received BP treatment), who attended the outpatient clinic at Aarhus University Hospital. The fractures were evaluated according to major and minor AFF criteria. In our OI cohort, we found that eight out of 55 patients had suffered a femoral fracture in adult year: five women and three men, aged 25 to 54 years. One patient had OI type I, two had OI type III, four had OI type IV, and one had OI type V. All fractures were associated with no or minimal trauma. Four patients had fractures that fulfilled the criteria of AFFs. Two of the four patients had received long-term BP treatment prior to the fracture and three patients had severe deformities of the femur. Femoral fractures in OI imitate AFFs. This suggests that bone deformity, collagen deficiencies, and alterations in mineralization of bone may cause femoral fractures that imitate AFFs even in the absence of antiresorptive treatment. Bone deformities should be monitored as part of the management of adult patients with OI. Continuous dull or aching pain in the groin or thigh should lead to radiographic examination. The radiologic appearance of femoral fractures may be different in patients with osteogenesis imperfecta (OI) and patients with osteoporosis, thus imitate atypical femoral fractures (AFF). We found that bone deformity, collagen deficiencies, and alterations in bone mineralization may cause femoral fractures that imitate AFFs even in the absence of antiresorptive treatment.

Background and purpose — The stem on the tibial component of total knee arthroplasty provides mechanical resistance to lift-off, shear forces, and torque. We compared tibial components with finned stems (FS) and I-beam block stems (IS) to assess differences in implant migration. Patients and methods — In a patient-blinded RCT, 54 patients/knees (15 men) with knee osteoarthritis at a mean age of 77 years (70–90) were randomly allocated to receive tibial components with either a FS (n = 27) or an IS (n = 27). Through 5 to 7 years’ follow-up, implant migration was measured with RSA, periprosthetic bone mineral density (BMD) was measured with DXA, and surgeons reported American Knee Society Score (AKSS). Results — At minimum 5 years’ follow-up, maximum total point motion (MTPM) was higher (p = 0.04) for IS (1.48 mm, 95% CI 0.81–2.16) than for FS (0.85 mm, CI 0.38–1.32) tibial components. Likewise, total rotation (TR) was higher (p = 0.03) for IS (1.51˚, CI 0.78–2.24) than for FS (0.81˚, CI 0.36–1.27). Tibial components with IS externally rotated 0.50° (CI –0.06 to 1.06) while FS internally rotated 0.09° (CI –0.20 to 0.38) (p = 0.03). Periprosthetic bone stress-shielding was higher (p < 0.01) up to 2 years’ follow-up for IS compared with FS in the regions medial to the stem (–13% vs. –2%) and posterior to the stem (–13% vs. –2%). Below the stem bone loss was also higher (p = 0.01) for IS compared with FS (–6% vs. +1%) up to 1-year follow-up. Knee score improved similarly in both groups up to 5 years’ follow-up. Interpretation — Periprosthetic bone stress-shielding medial and posterior to the stem until 2 years, and tibial component migration at 5 years, was less for a finned compared with an I-shaped block stem design. Trial registration:ClinicalTrials.gov identifier: NCT00175136.

Genu valgus is a condition characterised by a lateral shift of the knee's mechanical axis. The deformity can be characterised using clinical examinations and long hip-knee-ankle (HKA) angles, but it is unclear how these investigations correlate with each other. Our aim was to examine the correlation between clinical and radiographic measurements of the lower extremities in children.A total of 49 children between 5.9 and 16.7 years of age who had been referred with genu valgum deformity were included. They all had their intermalleolar (IM) distance measured and a standardised anterior-posterior radiograph of the lower extremities taken. IM distance was adjusted for the mean tibial and femoral length to adjust for differences in leg length. We calculated the Spearman's rank correlation coefficient to study the reliability between radiographs and clinical examinations.We found no correlation between clinical IM distance and the HKA angles. Spearman's rho for comparison between adjusted clinical IM distance measurements and HKA angles on radiographs was found to be 0.36.We found a poor correlation between clinical examinations and HKA angles as data were corrected for leg length. More studies are needed to provide clear recommendations for following children with malalignment.none.The study was registered with the Danish Data Protection Agency.

BACKGROUND: Congenital muscular torticollis (CMT) is seen in childhood and presents within months after birth. The etiology remains unknown; however, medical textbooks suggest trauma at birth as a main reason. The aim of this study was to systematically describe obstetric and perinatal outcomes in a population of children with a confirmed congenital muscular torticollis diagnosis.MATERIALS AND METHODS: Children with a validated diagnosis of congenital muscular torticollis born at Aarhus University Hospital from 2000 to 2014 were included in the study. Information on perinatal, intrapartum and neonatal characteristics were obtained from databases and from medical records, and systematically described.RESULTS: In this study, there were no differences in birth characteristics in children with left- and right-sided torticollis, between boys and girls or between the conservatively treated and the children who needed surgery. Most of the children with congenital muscular torticollis in this study were delivered at term without signs of birth complications or trauma. None experienced moderate or severe asphyxia.CONCLUSIONS: The results of the present study suggests that complicated birth or birth trauma may not be the main cause of congenital muscular torticollis and point towards intrauterine and prenatal reasons for its development. LEVEL OF EVIDENCE ACCORDING TO OCEBM LEVELS OF EVIDENCE WORKING GROUP: 3.

BACKGROUND AND PURPOSE: Current techniques for epiphysiodesis involve opening of cortical windows; use of staples, screws, and tension devices; and fusion with curettes or drills. Complications may have serious consequences. There is a need for a more reliable, precise, and less traumatic procedure that overcomes the known complications from existing techniques. We analyzed a new epiphysiodesis technique using radio-frequency ablation (RFA) in a porcine model.METHODS: Six 35-kg and two 25-kg immature pigs were used. 1 hind leg of each animal was randomly selected and the proximal tibia growth plate was ablated laterally and medially. The contralateral leg was used as a control. MR images were obtained immediately after the ablation and 12 weeks later for 6 animals, and 24 weeks later for the other 2 animals. CT was done for the 2 animals that were followed for 24 weeks for proof of bone bridges.RESULTS: Both tibias were equal in length initially. At the 12-week follow-up, there was an average leg length discrepancy of 3.9 mm (95% CI: 3.0-4.8), and at 24 weeks the difference was 8.4 mm and 7.5 mm. No damage to the adjacent tissue was found. Bone bridges and physeal closure were found after 24 weeks. The pigs showed no discomfort after the intervention.INTERPRETATION: We found RFA to be feasible for epiphysiodesis in a pig model. The method is minimally invasive and recovery may be quick compared to conventional methods. We recommend that the method should be tested in larger-scale safety studies before clinical application.

BACKGROUND: Several treatments have been described for leg length discrepancy. Epiphysiodesis is the most commonly used because of its effectiveness. Thermal epiphysiodesis using radiofrequency ablation (RFA) alters the growth plate morphology without damaging the adjacent articular cartilage; it is a minimally invasive method that has shown excellent results in animal models. This study describes the macro and micro morphology after the procedure.MATERIALS AND METHODS: Epiphysiodesis using RFA was performed in vivo for 8 min (92-98 °C) at two ablation sites (medial and lateral) in one randomly-selected tibia in eight growing pigs. The contralateral tibia was used as control. After 12 weeks, the pigs were killed and the tibiae harvested. The specimens were studied macroscopically and histology samples were obtained. Physeal morphology, thickness and characteristics were then described.RESULTS: Macroscopically, the articular cartilage was normal in all the treated tibiae. Microscopically, the physis was detected as a discontinuous line on the treated tibiae while it was continuous in all controls. In the control specimens, the mean thickness of the physis was 625 µm (606-639, SD = 14). All the physeal layers were organized. In the ablated specimens, disorganized layers in a heterogeneous line were observed. Bone bridges were identified at the ablation sites. The central part of the physis looked normal. Next to the bone bridge, the physis was thicker and presented fibrosis. The mean thickness was 820 µm (628-949, SD = 130). No abnormalities in the articular cartilage were observed.CONCLUSIONS: Thermal epiphysiodesis with RFA disrupts the physeal morphology and causes the formation of bone bridges at the ablation sites. This procedure does not damage the adjacent articular cartilage. The damaged tissue, next to the bone bridges, is characterized by disorganization and fibrosis.

Background Seated postural stability can be measured using Tekscan, CONFORMat. Standing postural stability has gained great clinical and, research value by use of different force platforms with mostly good reliability. No reliability testing or biologic variation assessment has been documented regarding seated balance. This study determines the reliability of the parameters of seated balance in healthy children using the Tekscan CONFORMat equipment. Methods Sixty-six healthy children completed six measurements of seating position the first three with the child seated in a relaxed normal back position and the next three with the child seated in a complete up-right back position. The SAM software calculated five default parameters of balance (area, distance, variability, antero-posterior (AP) excursion and left–right excursion). Results Reliability parameters were assessed by one-way analysis of variance intra-class correlation (ICC) proving excellent reliability for relaxed and up-right back position with respect to distance (0.75/0.84) and good reliability with respect to variability (0.61/0.62) and area (0.61/0.60). AP excursion (0.41/0.59) and left–right excursion (0.54/0.24) showed fair to poor reliability. Conclusion In conclusion, two of the five default parameters of balance used in the Tekscan CONFORMat system are direction-independent parameters and have been found reproducible for measuring seated balance in children. This study can be used as reference for comparisons of seated balance in children with affected seated postural control and for evaluating a clinical treatment effect.

Aims To compare the structural durability of hydroxyapatite-tricalcium phosphate (HATCP) to autologous iliac crest bone graft in calcaneal lengthening osteotomy (CLO) for pes planovalgus in childhood. Patients and Methods We present the interim results of ten patients (HATCP, n = 6 and autograft, n = 5) with a mean age of 11.5 years (8.2 to 14.2) from a randomised controlled non-inferiority trial with six months follow-up. The primary outcome was the stability of the osteotomy as measured by radiostereometric analysis. A non-inferiority margin of ≤ 2 mm osteotomy compression was set. Results At six months the data showed that the osteotomy had been compressed by a mean 1.97 mm (99.8% confidence interval -1.65 to 5.60) more in the HATCP group than in the autograft group. Migration of the CLO grafted with HATCP stabilised at six months rather than at six weeks with autograft. Conclusion This is the first randomised trial to compare the efficacy of HATCP graft with autograft in terms of stability of CLO in children. Because of problems with the HATCP the trial was stopped. We do not recommend HATCP graft in its current structure for use in unfixed CLOs. Cite this article: Bone Joint J 2016;98-B:1554–62.

Background and purpose - Treatment of postoperative pain in children with cerebral palsy (CP) is a major challenge. We investigated the effect of epidural analgesia, high-volume local infiltration analgesia (LIA), and an approximated placebo control on early postoperative pain in children with CP who were undergoing unilateral hip reconstruction. Patients and methods - Between 2009 and 2014, we included 18 children with CP. The first part of the study was a randomized double-blind trial with allocation to either LIA or placebo for postoperative pain management, in addition to intravenous or oral analgesia. In the second part of the study, the children were consecutively included for postoperative pain management with epidural analgesia in addition to intravenous or oral analgesia. The primary outcome was postoperative pain 4 h postoperatively using 2 pain assessment tools (r-FLACC and VAS-OBS) ranging from 0 to 10. The secondary outcome was opioid consumption over the 21-h study period. Results - The mean level of pain 4 h postoperatively was lower in the epidural group (r-FLACC: 0.7; VAS-OBS: 0.6) than in both the LIA group (r-FLACC: 4.8, p = 0.01; VAS-OBS: 5.2, p = 0.02) and the placebo group (r-FLACC: 5.2, p = 0.01; VAS-OBS: 6.5, p

Background and purpose Lasting stability of cementless implants depends on osseointegration into the implant surface, and long-term implant fixation can be predicted using radiostereometric analysis (RSA) with short-term follow-up. We hypothesized that there would be improved fixation of high-porosity trabecular metal (TM) tibial components compared to low-porosity titanium pegged porous fiber-metal (Ti) polyethylene metal backings. Methods In a prospective, parallel-group, randomized unblinded clinical trial, we compared cementless tibial components in patients aged 70 years and younger with osteoarthritis. The pre-study sample size calculation was 22 patients per group. 25 TM tibial components were fixed press-fit by 2 hexagonal pegs (TM group) and 25 Ti tibial components were fixed press-fit and by 4 supplemental screws (Ti group). Stereo radiographs for evaluation of absolute component migration (primary effect size) and single-direction absolute component migration (secondary effect size) were obtained within the first postoperative week and at 6 weeks, 6 months, 1 year, and 2 years. American Knee Society score was used for clinical assessment preoperatively, and at 1 and 2 years. Results There were no intraoperative complications, and no postoperative infections or revisions. All patients had improved function and regained full extension. All tibial components migrated initially. Most migration of the TM components (n = 24) occurred within the first 3 months after surgery whereas migration of the Ti components (n = 22) appeared to stabilize first after 1 year. The TM components migrated less than the Ti components at 1 year (p = 0.01) and 2 years (p = 0.004). Interpretation We conclude that the mechanical fixation of TM tibial components is superior to that of screw-fixed Ti tibial components. We expect long-term implant survival to be better with the TM tibial component.

Udgivelsesdato: 2009-Oct Ceramic femoral heads were developed to reduce the wear of conventional ultrahigh-molecular-weight polyethylene (UHMWPE) bearing surfaces in THA. We compared the wear rates of PE acetabular components bearing against femoral heads of zirconia (Zr) or cobalt-chromium (CoCr) in young patients. One surgeon inserted CoCr femoral heads in all 33 patients (33 hips) having THA for primary osteoarthritis from 1996 to 1997 and then Zr femoral heads in all 34 patients (36 hips) from 1998 to 1999. The mean age of the entire cohort was 52.5 years (range, 29-64 years). The shells were solid and hydroxyapatite (HA) -coated, liners were argon-sterilized UHMWPE, and head size was 28 mm. The minimum clinical followup was 56 months (mean, 65 months; range, 56-77 months); minimum 5-year radiographs were available for 62 of the 68 patients. Wear analysis of digitized anteroposterior (AP) radiographs was performed with a computerized method. Demographic data were comparable in the two groups. Mean femoral head penetration rate was similar in the two types of heads (CoCr: 0.25 mm/year; range, 0.21-0.33 mm/year; Zr: 0.23 mm/year; range, 0.20-0.29 mm/year), as was mean linear wear (CoCr: 1.22 mm; range, 0.28-3.78 mm; Zr: 1.11 mm; range, 0.15-2.05 mm). There were no revisions. These data support skepticism regarding the clinical wear advantage of Zr compared with CoCr femoral heads. The explanation for the clinical similarity of wear, despite the theoretical advantages of ceramic heads, needs further investigation. Level of Evidence: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Implant stability is crucial for implant survival. A new surgical technique, compaction, has increased in vitro implant stability and in vivo fixation of nonweightbearing implants. However, the in vivo effects of compaction on weightbearing implants are unknown. As implants inserted clinically are weightbearing, the effects of compaction on weightbearing implants were examined. The hypothesis was that compaction would increase implant fixation compared with conventional drilling. Porous-coated titanium implants were inserted bilaterally into the weightbearing portion of the femoral condyles of dogs. In each dog, one knee had the implant cavity prepared with drilling, and the other knee was prepared with compaction. Eight dogs were euthanized after 2 weeks, and eight dogs were euthanized after 4 weeks. Femoral condyles from an additional eight dogs represented Time 0. Compacted specimens had higher bone-implant contact and periimplant bone density at 0 and 2 weeks, but not at 4 weeks. A biphasic response of compaction was found with a pushout test, as compaction increased ultimate shear strength and energy absorption at 0 and 4 weeks, but not at 2 weeks. This biphasic response indicates that compaction enhances implant fixation by mechanical and biological mechanisms. Therefore, compaction might have potential value in total joint replacement in the future.

Slipped capital femoral epiphysis (SCFE) is a relatively rare growth disturbance in the proximal femoral growth plate. It results in posterior displacement of the femoral head. Symptoms are an intermittent hip, knee or groin pain, which is exacerbated by sports, giving restricted hip motion, and sometimes a limping gait with out-toeing. SCFE is typically seen in overweight boys, but may also occur in normal-weight teenage girls. Early image diagnostic assessment of both hips is crucial, since slip severity and consequently the risk of disabling complications are strongly correlated to late diagnosis.

The tension band plating technique for hemiepiphysiodesis is new and advocated because it is believed to reduce the risk of premature closure of the growth plate compared to stapling. The benefit of the tension band plating technique has not yet been proven in experimental or randomized clinical studies. Ten weeks old domestic pigs in two randomized, paired studies were used. Right proximal tibia was randomized to medial epiphysiodesis by either stapling or tension band plating. Left side received the opposite treatment. Study A (n = 10): 9 weeks treatment. Study B (n = 8): implant removal after 9 weeks of treatment and 5 weeks of housing. Fractions of the chondrocyte layers were determined using quantitative histomorphometry. Mean heights of the growth plates were measured. No significant changes were observed between histomorphometric parameters in neither study A or B. Areas with disorganized cartilage tissue were abundant in 13/16 samples from study B and observed after both treatment with tension band plating and staples. Chondrocyte zone fractions did not differ between tension band plating and staple treatment in this randomized, paired animal study. The growth plate responded to release of hemiepiphysiodesis with abundant disorganized cartilage tissue in both groups. The histological response to hemiepiphysiodesis by tension band plating and staples appear to be similar. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 574–579, 2013

Hydroxyapatite (HA) coating of implant surfaces is believed to improve longevity of uncemented total hip arthroplasty (THA). However; it is speculated that HA particles may cause third body wear of the polyethylene (PE) liner with subsequent osteolysis and aseptic loosening of implants. We performed a retrospective comparison of two patient populations with cementless Mallory-Head acetabular components. The patients were identified in the Danish hip arthroplasty Registry (DHR); 77 patients had HA-coated cups and 73 patients had non-HA coated cups. Anteroposterior (AP) radiographs were analysed for PE wear, osteolysis was quantified and survival of the acetabular components was compared. The mean follow-up was 11 years. There were no cup revisions in the HA group and 7 cup revisions in the non-HA group (p After 11.1 years of follow-up non-HA coated cups had a higher revision rate. Increased PE wear with HA-coated cups did not have a negative influence on the revision rate, but may result in a need for revision surgery over time.

Udgivelsesdato: 2009-Nov Hydroxyapatite (HA) particles have long been suspected to disintegrate from implant surfaces, become entrapped in joint spaces of orthopaedic bearing couples, and start a cascade leading to progressive polyethylene (PE) wear, increased osteolysis, and aseptic loosening. We compared cup revision at 15 years' followup in a randomized group of patients with 26 cementless THA components with titanium (Ti) versus first-generation HA coating. We also assessed radiographic PE wear and osteolysis to the 12-year followup or end point revision at a minimum of 5 years (mean, 10.9 years; range, 5-12.6 years). Two Ti-coated cups (17%) and eight HA-coated cups (57%) were revised at 15 years' followup. Femoral head penetration rate was 0.46 mm/year (standard deviation, 0.26) with the HA-coated cups (n = 12) and 0.38 mm/year (standard deviation, 0.14) with the Ti-coated cups (n = 10); we observed a wide variance of linear wear with the HA-coated cups. We also observed a positive association between high wear rate and revision, and between a high volume of osteolysis and revision. Our findings suggest inferior survival of medium-thickness spray-dried HA-coated cups with individual cases of excessive PE wear and premature cup failure. These findings apply to first-generation modular cups and may not apply to other cup designs and new HA-coating technologies. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

The effect of bone compaction vs conventional drilling on the fixation of hydroxyapatite-coated implants was examined in a weight-bearing canine model. In each dog, one knee joint had the implant cavity prepared with drilling, the other with compaction. Eight dogs were euthanized after 2 weeks and 8 dogs after 4 weeks. Femoral condyles from additional 7 dogs represented time 0. Compacted specimens had significantly higher bone implant contact and energy absorption at time 0. Compaction significantly increased ultimate shear strength at 0 and 2 weeks. There was no significant difference in implant fixation after 4 weeks. The results of this study suggest that compaction may be beneficial in optimizing the crucial initial implant stability, even when hydroxyapatite-coated implants with osteoconductive properties are inserted in vivo.

A new bone preparation technique, compaction, has increased fixation of implants inserted with exact-fit or press-fit to bone. Furthermore, a demonstrated spring-back effect of compacted bone might be of potential value in reducing the initial gaps that often exist between clinical inserted implants and bone. However, it is unknown whether the compression and breakage of trabeculae during the compaction procedure results in impaired gap-healing of compacted bone. Therefore, we compared compaction with conventional drilling in a canine gap model. Grit-blasted titanium implants (diameter 6 mm) were bilaterally inserted into cavities initially expanded to 8 mm diameters in the proximal humeri. Each dog served as its own control; thus, one humerus had the implant cavity prepared with compaction, the other with drilling. Eight dogs were euthanized after 2 weeks, and 7 dogs after 4 weeks. Humeri from additional 7 dogs represented time 0. At time 0 a spring-back effect of compacted bone was demonstrated as cavities, initially expanded to 8 mm by compaction, were reduced to a median cavity diameter of 6.6 mm. In contrast, cavities initially expanded to 8 mm by drilling, had a median cavity diameter of 8.0 mm at time 0. Compaction significantly increased all push-out parameters at 2 weeks. Compaction significantly increased peri-implant bone density at 0 and 2 weeks, and bone implant contact at 2 and 4 weeks. The faster mechanical and histological fixation with compaction indicates that the beneficial effect of reduced gap size, as compacted bone springs back, is not eliminated by an impaired gap-healing of compacted bone.

Background: The Danish selective screening programme for developmental dysplasia of the hip (DDH) is based on clinical examinations and screening for risk factors of all newborns. Studies have shown a low positive predictive value (PPV) of clinical hip examinations performed by a heterogenic group of screeners in the United Kingdom. As no true definition of DDH exists, the PPV is difficult to assess.Aim: To establish the positive predictive value (PPV) of clinical hip examinations performed by referrers in the Danish screening programme for Developmental Dysplasia of the Hip (DDH) utilising three definitions of true positive DDH diagnosis.Materials and Methods: We retrospectively identified 290 children (169 female) referred during a four-year period to the orthopaedic outpatient clinic at our institution with a positive clinical hip examination. We calculated PPV for clinical hip examinations across three definitions of a true positive clinical hip examination for all referrers and subgroups consisting of general practitioners, midwives and paediatricians. The PPV for clinical hip examinations was calculated for paediatric orthopaedic surgeons, who were blinded to the results of ultrasound examination, using one of the three definitions.Results: PPV of clinical hip examinations for all referrers were 5.4%, 3.6% and 1.8% with the definition of a true positive DDH diagnosis defined as clinical instability found by orthopaedic surgeon, ultrasound classification = Graf IIc or both definitions combined, respectively. PPV of clinical hip examinations performed by orthopaedic surgeons was 33.3% with a true positive clinical examination defined as an ultrasound classification = Graf IIc.Interpretation / Conclusion: In this first review of results from the Danish screening programme for DDH, we conclude that the positive predictive value of clinical hip examinations made by referrers in the Danish screening programme for DDH is low. As clinical examinations are a critical part of the selective screening for DDH, this study demonstrates a need for focused training of screeners in clinical hip examinations to improve the screening of DDH in Denmark.

INTRODUCTION: The aim of this study was to review risk factors used in the current Danish screening programme for developmental dysplasia of the hip (DDH) and the self-reported recognition of these risk factors among midwives, general practitioners (GP) and GPs in training. METHODS: A survey of regional DDH referral guidelines was conducted through online regional guideline databases. Furthermore, risk factors used as referral criteria for DDH were compared across regions. Using an online survey, we asked midwives, GPs and GPs in training to identify which of six risk factors for DDH were currently featured as referral criteria for specialised DDH examination in the referral guidelines of their employment region. Answers were compared with the DDH referral guidelines of the responders' employment region. RESULTS: We collected 178 survey responses and 11 local and regional DDH referral guidelines. Six risk factors were identified from referral guidelines (breech presentation, oligohydramnios, family history of DDH, clubfeet, twins and premature birth). Overall, correct answer percentages for currently used risk factors for DDH as specified in the corresponding regional guidelines were: 96% (breech presentation), 90% (family history of DDH), 66% (twins), 63% (premature birth), 34% (clubfeet) and 29% (oligohydramnios). CONCLUSIONS: This study found variation in the referral criteria among Danish regional DDH referral guidelines and an overall high level of recognition for two out of six referral criteria but a low level of recognition for the remaining four. FUNDING: The authors received no financial support for the research conducted in preparation of this article. TRIAL REGISTRATION: not relevant.