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Purpose: This study aimed to evaluate the association between the progression of medial joint space (MJS) narrowing, medial meniscus extrusion (MME) and clinical scores and the tibial tunnel position in pullout repairs for medial meniscus posterior root tears (MMPRTs). Methods: This retrospective study examined 54 patients. Changes in MJS (ΔMJS), MME (ΔMME) and clinical scores and their relationship with the tibial tunnel position were evaluated using correlation coefficients. The distance from the anatomical to technical attachment position in the tibial tunnel position was measured in the anterior and medial directions, and the direct distance was measured using the Pythagorean theorem. Results: The mean ΔMJS and ΔMME were 0.6 ± 0.8 and 1.3 ± 1.3 mm, respectively, and the mean anterior, medial and direct distances were 1.4 ± 2.3, 2.2 ± 1.7 and 3.4 ± 1.7 mm, respectively. ΔMJS had a significant positive correlation with the medial (r = 0.580, p < 0.001) and direct (r = 0.559, p < 0.001) distances, while ΔMME had a significant positive correlation with direct distance (r = 0.295, p = 0.030). Several clinical scores were significantly negatively correlated with these distances. Conclusion: In transtibial pullout repair for MMPRTs, accurate tibial tunnel position delayed the progression of MJS narrowing and MME, leading to improved clinical outcomes. The progression of MJS narrowing was associated with the mediolateral direction of the tibial tunnel position, while the clinical scores were associated with the anteroposterior direction of the tibial tunnel position. These findings indicate the need to orient the tip of the guide in a more posterolateral direction when creating the tibial tunnel. Level of Evidence: Level IV. [ABSTRACT FROM AUTHOR]

Background: Paired related-homeobox 1 (PRRX1) is a transcription factor in the regulation of developmental morphogenetic processes. There is growing evidence that PRRX1 is highly expressed in certain cancers and is critically involved in human survival prognosis. However, the molecular mechanism of PRRX1 in cancer malignancy remains to be elucidated. Methods: PRRX1 expression in human Malignant peripheral nerve sheath tumours (MPNSTs) samples was detected immunohistochemically to evaluate survival prognosis. MPNST models with PRRX1 gene knockdown or overexpression were constructed in vitro and the phenotype of MPNST cells was evaluated. Bioinformatics analysis combined with co-immunoprecipitation, mass spectrometry, RNA-seq and structural prediction were used to identify proteins interacting with PRRX1. Results: High expression of PRRX1 was associated with a poor prognosis for MPNST. PRRX1 knockdown suppressed the tumorigenic potential. PRRX1 overexpressed in MPNSTs directly interacts with topoisomerase 2 A (TOP2A) to cooperatively promote epithelial-mesenchymal transition and increase expression of tumour malignancy-related gene sets including mTORC1, KRAS and SRC signalling pathways. Etoposide, a TOP2A inhibitor used in the treatment of MPNST, may exhibit one of its anticancer effects by inhibiting the PRRX1–TOP2A interaction. Conclusion: Targeting the PRRX1–TOP2A interaction in malignant tumours with high PRRX1 expression might provide a novel tumour-selective therapeutic strategy. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to evaluate the longitudinal changes in medial meniscus extrusion (MME) and clinical scores at multiple time points up to 3 years after pullout repair for medial meniscus posterior root tears (MMPRTs). Methods: This retrospective case series study included 64 patients who underwent pullout repair for MMPRTs and four MRI evaluations (preoperatively and at 3 months, 1 year, and 3 years postoperatively). MME was measured during the same time points. Clinical scores were assessed four times: preoperatively and at 1, 2, and 3 years postoperatively. Additionally, a multivariate analysis was performed on the change in MME (ΔMME) from the preoperative measurement point to 3 years postoperatively. Results: The ΔMME per month from the preoperative measurement point to 3 months postoperatively, from 3 months to 1 year postoperatively, and from 1 to 3 years postoperatively were 0.30, 0.05, and 0.01 mm/month, respectively. All clinical scores significantly improved 3 years postoperatively (p < 0.001). In a multiple regression analysis for ΔMME from the preoperative measurement point to 3 years postoperatively, sex significantly affected the outcome (p = 0.039). Conclusion: Following pullout repair for MMPRTs with well-aligned lower extremities, although MME progression could not be entirely prevented, the rate of progression decreased over time, and clinical scores improved. In particular, MME progressed markedly during the first 3 months postoperatively. Additionally, sex had a significant influence on MME progression, suggesting that males may be able to expand the indications of pullout repair for MMPRTs. [ABSTRACT FROM AUTHOR]

Background: Although bone and soft tissue sarcoma is recognized as a rare cancer that originates throughout the body, few comprehensive reports regarding it have been published in Japan. Patients and methods: Bone and soft tissue sarcomas were tabulated from the Cancer Registries at eight university hospitals in the Chugoku–Shikoku region. Prognostic factors in cases were extracted in a single facility and have been analyzed. Results: From 2016 to 2019, 3.4 patients with bone and soft tissue sarcomas per a general population of 100,000 were treated at eight university hospitals. The number of patients who underwent multidisciplinary treatment involving collaboration among multiple clinical departments has been increasing recently. In the analysis carried out at a single institute (Ehime University Hospital), a total of 127 patients (male/female: 54/73) with an average age of 67.0 y (median 69.5) were treated for four years, with a 5-year survival rate of 55.0%. In the analysis of prognostic factors by multivariate, disease stage and its relative treatment, renal function (creatinine), and a patient's ability of self-judgment, and a patient's mobility and physical capability were associated with patient prognosis regarding bone and soft tissue sarcomas. Interestingly, age did not affect the patient's prognosis (> 70 vs ≦ 70). Conclusions: Physical and social factors may affect the prognosis of patients with bone and soft tissue sarcomas, especially those living in non-urban areas. [ABSTRACT FROM AUTHOR]

Purpose: This retrospective study aimed to investigate the relationship between intercondylar notch width (ICNW), osteophyte width (OW), and the healing of medial meniscus posterior root tears (MMPRTs) following arthroscopic pullout repair. Methods: The study included 155 patients diagnosed with MMPRTs who underwent transtibial pullout repair. Meniscal healing status was evaluated on second‐look arthroscopy using a previously reported meniscus healing score. Patients were divided into two groups based on this score: the high healing score (group HH, healing score ≥ 8 points) and suboptimal healing score (group SO, healing score ≤ 6 points) groups. Computed tomography scans were performed on patients 1 week postsurgery. ICNW and OW widths were measured and relatively evaluated based on their ratio to the intercondylar distance (ICD), represented as the ICNW/ICD ratio (%) and OW/ICD ratio (%), respectively. Patient‐reported outcomes were assessed preoperatively and on second‐look arthroscopy using the Knee injury and Osteoarthritis Outcome Score (KOOS) and visual analogue scale (VAS). Results: There were no significant demographic differences between the SO and HH group (n = 35 and 120 patients, respectively). Regarding radiographic measurements, significant differences were observed in the ICNW/ICD ratio (group SO, 24.2%; group HH, 25.2%; p = 0.024), OW (group SO, 2.6 mm; group HH, 2.0 mm; p < 0.001), and OW/ICD ratio (group SO, 3.5%; group HH, 2.7%; p < 0.001). Both groups had similar preoperative clinical scores, but postoperative clinical scores, including KOOS‐activities of daily living (group SO, 83.4; group HH, 88.7; p = 0.035) and VAS (group SO, 19.1; group HH, 11.3; p = 0.005), were significantly better in group HH. Conclusion: The study suggests that ICNW and OW may play a crucial role in MMPRT healing following arthroscopic pullout repair, as evidenced by the worse clinical outcomes associated with a narrower ICNW and wider OW. These findings highlight the potential significance of ICNW and OW assessments when evaluating meniscal repair indications. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Purpose: This study investigated the impact of weight change on the success of transtibial pullout repair for medial meniscus (MM) posterior root tears (MMPRTs). Methods: The study included 129 patients diagnosed with MMPRTs who had undergone transtibial pullout repair. The patients were screened between July 2018 and November 2021. Patient‐reported outcomes were assessed preoperatively and at 12 months postoperatively using the Knee injury and Osteoarthritis Outcome Score (KOOS). MM extrusion (MME) and ΔMME (postoperative MME – preoperative MME) were calculated preoperatively and at 12 months postoperatively using magnetic resonance imaging. Results: Patients were divided into weight loss (body mass index [BMI] decrease of at least 0.5 kg/m2 after primary repair; n = 63) and weight gain (BMI increase of at least 0.5 kg/m2; n = 66) groups. Both groups had similar demographic variables and preoperative clinical scores; patient‐reported outcomes significantly improved postoperatively. The weight loss group had significantly greater improvement in KOOS–quality of life (weight loss, 29.4 ± 23.7; weight gain, 23.9 ± 27.6; p = 0.034), lower postoperative MME (weight loss, 3.9 ± 1.7 mm; weight gain, 4.2 ± 1.2 mm; p = 0.043) and lower ΔMME (weight loss, 0.8 ± 0.8 mm; weight gain, 1.2 ± 0.9 mm; p = 0.002) than the weight gain group. Total arthroscopic healing scores (weight loss, 7.6 ± 1.0; weight gain, 7.2 ± 1.5; p = 0.048) and associated subscales, including anteroposterior bridging tissue width (weight loss, 4.0 ± 0.0; weight gain, 3.8 ± 0.7; p = 0.004) and MM posterior root stability (weight loss, 2.6 ± 0.7; weight gain, 2.4 ± 0.7; p = 0.041), significantly differed between the groups. Conclusions: Weight loss was associated with better meniscal healing and less MME progression after MMPRT repair, highlighting the significance of weight management in individuals undergoing meniscal surgery. These findings provide valuable insights into the clinical significance of weight loss in the success of transtibial pullout repair for MMPRTs. Level of Evidence: Level III. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to compare medial meniscus extrusion (MME) in patients with partial medial meniscus posterior root tears (MMPRTs) through magnetic resonance imaging (MRI) conducted at two-time points and to determine whether patient characteristics or MME measurements differ in patients who respond to nonoperative treatment compared with those who require surgical treatment. Methods: Thirty-seven patients with partial MMPRTs underwent two MRI scans during nonoperative management or before pull-out repair. Among these, 17 patients received nonoperative management, and 20 underwent pull-out repair. Partial MMPRTs were diagnosed based on the MRI findings. MME measurements were performed on both MRI scans. Statistical and receiver operating curve (ROC) analyses were performed. Results: The duration between the two MRI scans was significantly shorter in the pull-out repair group than in the nonoperative management group. The increase in MME (ΔMME) on MRI scans was significantly greater in the pull-out repair group than in the nonoperative management group. Linear regression analysis revealed a weak correlation between the MRI interval and ΔMME in the nonoperative management group and a moderate correlation in the pull-out repair group. In the ROC construction, the cut-off value for ΔMME that requires surgical intervention was 0.41 mm, with a sensitivity and specificity of 85.0% and 52.9%, respectively. Conclusion: Patients with partial MMPRTs requiring surgical treatment had greater MME progression in a shorter time and a time-dependent increase in MME. Therefore, a ΔMME of ≥ 0.41 mm may be useful in deciding surgical intervention based on MRI retests. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: Untreated or overlooked medial meniscus posterior root tears (MMPRTs) induce sequential knee joint degradation. We evaluated epidemiological features of acute MMPRT for its early detection and accurate diagnosis. Methods: Among 330 MMPRT patients from 2018 to 2020, those who underwent arthroscopic pullout repairs were enrolled. Patients who underwent non-operative treatment or knee arthroplasty, those with a cruciate ligament-deficient knee or advanced osteoarthritis of the knee, and those with insufficient data were excluded. Finally, we retrospectively evaluated data from 234 MMPRTs (female: 79.9%, complete tears: 92.7%, mean age: 65 years). Welch's t-test and Chi-squared test were used for pairwise comparisons. Spearman's rank correlation analysis was performed between age at surgery and body mass index (BMI). Multivariable logistic regression analysis with stepwise backward elimination was applied to the values as risk factors for painful popping events. Results: In both sexes, there were significant differences in height, weight, and BMI. In all patients, there was a significant negative correlation between BMI and age (ρ = − 0.36, p < 0.001). The BMI cutoff value of 27.7 kg/m2 had a 79.2% sensitivity and a 76.9% specificity for detecting MMPRT patients aged < 50 years. A painful popping event was confirmed in 187 knees (79.9%), and the frequency was significantly reduced in partial tears as compared to complete tears (odds ratio: 0.080, p < 0.001). Conclusion: Higher BMI was associated with a significantly younger age of MMPRT onset. Partial MMPRTs had a low frequency of painful popping events (43.8%). [ABSTRACT FROM AUTHOR]

Purpose: Transtibial pullout repair improves the clinical outcomes of medial meniscus (MM) posterior root tears (PRTs); however, reducing MM extrusion remains challenging. Thus, the purpose of this study was to examine the role of additional posterior anchoring (PA) during pullout repair in reducing the severity of MM extrusion compared to pullout repair alone. Methods: Patients who underwent pullout repair with two-cinch stitches (TCS) only or TCS combined with PA (TCS-PA)—deployment of an additional suture anchor in the posteromedial corner of MM—were included retrospectively. MM medial and posterior extrusion (MMME and MMPE), MM extrusion and remaining volume (MMEV and MMRV), and corresponding ratios were evaluated pre-operatively and three months post-operatively using a three-dimensional meniscal model at 10° and 90° of knee flexion and compared within and between groups. Results: A total of 15 and 16 patients treated with TCS and TCS-PA, respectively, were enrolled. At 90° knee flexion, both techniques significantly reduced MMPE (TCS: 4.2 ± 0.7 mm to 3.5 ± 0.6 mm, p < 0.05; TCS-PA: 3.7 ± 0.8 mm to 2.8 ± 0.7 mm, p < 0.05) at three months post-operatively. TCS-PA reduced MMPE more significantly than TCS alone (p < 0.05). Only TCS-PA significantly improved the MMEV and MMRV ratios (39.6 ± 8.9% to 28.1 ± 6.0%, p < 0.05 and 60.4 ± 8.9% to 71.9 ± 6.0%, p < 0.05, respectively). Significance was not found in all other comparisons. Conclusions: Both techniques improved MMPE at knee flexion at the three month follow-up, with TCS-PA providing significantly superior results. Our findings support the evidence that the application of PA may be an effective surgical option for alleviating persistent MMPE. [ABSTRACT FROM AUTHOR]

Purpose: The extent to which arthropathic changes progress after medial meniscus posterior root tear (MMPRT) repair remains controversial. This retrospective study assessed medial joint space (MJS) narrowing progression after pullout repair for MMPRT and identified the correlating factors. Methods: We included 56 patients who underwent pullout repair for MMPRT. The MJS of the bilateral knees was assessed with radiography using the fixed-flexion view. A second-look arthroscopy was performed one year post-operatively for all patients. The baseline characteristics, clinical scores, Kellgren–Lawrence (KL) grade, and medial meniscus extrusion (MME) were identified. Statistical comparisons and correlation analyses were conducted. Results: The MJS narrowing width was significantly larger in MMPRT knees than in contralateral knees (0.51 ± 0.85 mm vs. 0.09 ± 0.49 mm, p < 0.001). KL grade progression was observed in 23.2% (13/56) of patients. There was a significant difference between pre- and post-operative MME values, indicating MME progression (p < 0.001). Each clinical score showed significant improvement one year post-operatively (p < 0.001). Positive correlations were found between MJS narrowing and pre-operative MJS (coefficient = 0.510, p < 0.001), rate of change in MJS (coefficient = 0.929, p < 0.001), and increase in MME (ΔMME) (coefficient = 0.506, p < 0.001). Conclusion: Knees that underwent pullout repair for MMPRT showed progression of MJS narrowing by 0.51 mm at one year post-operatively, although clinical scores markedly improved. Correlating factors for MJS narrowing were pre-operative MJS, rate of change in MJS, and ΔMME. Preventing MME progression is essential for preventing arthropathic changes. [ABSTRACT FROM AUTHOR]

Background: Arthroscopic ankle arthrodesis (AAA) has risks of complications, such as delayed union and non-union. The number and direction of the inserted screws have been reported as important factors affecting the time to union of AAA. However, the ratio of inter-screw distance (ISD) to tibial width (TW) in different planes has not been investigated. Therefore, we aimed to explore the effect of this ratio on bone union following AAA. Methods: We retrospectively enrolled 63 patients (64 ankles) undergoing AAA from 2013 to 2019. Then, their age, body mass index (BMI), sex, diabetes mellitus (DM) status, Takakura–Tanaka classification, number of screws and radiographic parameters were analysed. Results: The patients had a mean age of 70.3 (range, 45–91) years. Bone fusion was achieved in 57 ankles (89%) in a mean period of 3.3 (range, 2–6) postoperative months. There were four cases of delayed union and three of non-union. No significant differences in age, BMI, sex, DM, Takakura–Tanaka classification, and number of screws could be detected between the groups. However, the sagittal ISD/TW ratio was significantly larger in the union group than in the delayed/non-union group with a cut-off value of 57.0%. Conclusion: Larger sagittal ISD/TW ratios result in reduced post-AAA delayed union or non-union. The surgeon should be aware that the anterior and posterior screw widths should be approximately 60% or more of the anteroposterior width of the tibia. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to compare the clinical outcomes of different subtypes of type 2 medial meniscus posterior root tears following transtibial pullout repair. Methods: In total, 147 patients (mean age: 66.2 ± 8.3 years) who were diagnosed with type 2 medial meniscus posterior root tears and underwent transtibial pullout repair were included. Patients were divided into 2A (n = 31), 2B (n = 90), and 2C (n = 26) groups according to tear type. Clinical outcomes were assessed pre-operatively and at second-look arthroscopy using the Knee injury and Osteoarthritis Outcome Score. The meniscal healing status was evaluated at second-look arthroscopy. Medial meniscus extrusion was calculated using magnetic resonance imaging pre-operatively and at second-look arthroscopy. Results: No significant differences in pre-operative or post-operative clinical scores were observed between each subtype, although clinical scores improved post-operatively for each subtype. Significant differences were noted in the anteroposterior width of the bridging tissues at second-look arthroscopy (2A, 7.1 ± 1.2; 2B, 6.2 ± 1.7; and 2C, 6.2 ± 1.7 mm; p = 0.045); type 2A tears were the widest. There was a significant difference in post-operative medial meniscus extrusion (2A, 3.2 ± 0.9; 2B, 4.0 ± 1.2; and 2C, 4.0 ± 1.4 mm; p = 0.004) and its progression (2A, 0.7 ± 0.6; 2B, 1.2 ± 0.8; and 2C, 1.2 ± 0.8 mm; p = 0.008), and type 2A tears were the shortest. Conclusion: Although there was no significant difference in the post-operative clinical scores among different type 2 tears in the short term, type 2A tears showed better healing and medial meniscus extrusion progression prevention, thus indicating the usefulness of classifying tear type in estimating post-operative outcomes. Level of Evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: Medial meniscus (MM) posterior root tears (PRTs) lead to abnormal kinematic changes in the knee and may induce pathological external rotation of the tibia during knee flexion. This study aimed to investigate changes in the length and inclination of the anterior cruciate ligament (ACL) after MM posterior root repair using magnetic resonance imaging (MRI). Methods: This retrospective study included 44 patients who underwent MM posterior root repair between 2016 and 2019. Clinical outcomes were evaluated before and after surgery. MRI examinations were performed at 10°/90° of knee flexion preoperatively and 3 months postoperatively. The ACL length, proximal angle, and distal angle were determined using the sagittal view. MM extrusion and ACL inclination angle were determined using the coronal view. Results: Clinical outcomes significantly improved 1 year after surgery. The postoperative ACL length (29.7 ± 2.4 mm) and proximal angle (47.0 ± 7.4°) at 90° of knee flexion decreased relative to the preoperative values (31.5 ± 2.3 mm and 51.8 ± 8.7°, P < 0.01). The postoperative ACL inclination (64.9 ± 5.6°) at 10° of knee flexion decreased relative to the preoperative value (69.7 ± 5.6°, P < 0.01). Conclusion: Pathologically-stretched linear ACL at 90° of knee flexion and a steep ACL inclination at 10° of knee flexion could be reduced after MM posterior root repair. This suggests that pullout repair could restore MM function as a secondary stabilizer, thereby preventing meniscal and cartilage degeneration. [ABSTRACT FROM AUTHOR]

Introduction: The cumulated ambulation score (CAS) has been developed as an index for evaluating mobility in the early postoperative period. This study aimed to estimate the association between CAS and independent ambulation after surgery for proximal femur fractures. Materials and methods: This retrospective cohort study included 223 elderly patients who underwent surgery for proximal femur fractures and had independent ambulation before the injury. Multivariable logistic regression analyses with cognitive impairment, pre-injury Barthel index, and CAS as the test variables were used to predict independent ambulation at 2 weeks (model 1) and 3 months (model 2) postoperatively. We established scoring systems based on the modeling results. Results: The number of patients with independent ambulation at 2 weeks and 3 months postoperatively was 115 and 169, respectively. Univariate analysis showed that the CAS was significantly associated with independent ambulation at 2 weeks and 3 months postoperatively. Multivariable analysis showed that models 1 and 2 had good predictive accuracies, with areas under the receiver-operating characteristic curve of 0.855 and 0.868, respectively. Among the explanatory variables, only the CAS in model 2 was not significantly associated with the postoperative ambulatory ability. Scoring systems for both models 1 and 2 also had good predictive accuracies, with cut-off scores of 3.5 for model 1 and 9.5 for model 2. Conclusions: The CAS predicted independent ambulation at 2 weeks postoperatively; however, this relationship was limited at 3 months postoperatively. Therefore, the CAS may help estimate independent ambulation at discharge from an acute-care hospital. [ABSTRACT FROM AUTHOR]

Purpose: We propose coronal shear fracture of the femoral neck (CSFF) as a new type of fracture that differs from a basicervical fracture. This study aimed to present the incidence of CSFF and compare its clinical characteristics and outcomes with those of basicervical fractures. Methods: In this multicenter retrospective cohort study, 2207 patients with hip fractures were identified using computed tomography (CT), 17 and 27 patients were diagnosed with CSFF (CSFF group) and basicervical fractures (basicervical fracture group), respectively. The primary outcome was reoperation, while the secondary outcomes were postoperative radiographic findings, ambulatory ability, and 1-year mortality rate. These outcomes were compared between the two groups. We also conducted diagnostic reliability tests for these fractures using the Cohen's kappa coefficient. Results: The incidence of CSFF and basicervical fractures in the 2207 patients were 0.77% and 1.22%, respectively. The inter-and intra-observer agreements for the diagnosis were almost perfect. The comorbidity score was significantly higher in the CSFF group than in the basicervical fracture group. No reoperations occurred in both groups. There were no significant intergroup differences in the postoperative radiographic findings. The 1-year mortality rate was higher in the CSFF group than in the basicervical fracture group (38.5% vs. 5.3%; odds ratio: 11.9, 95% CI: 1.2–118.5; p = 0.025). Conclusion: This study presents the definition and incidence of CSFF with a high diagnostic reliability. Patients with CSFF had similar reoperation rate postoperative radiographic outcomes to basicervical fractures, while 1-year mortality rate was high. [ABSTRACT FROM AUTHOR]

Purpose: Medial meniscus posterior root tears (MMPRTs) occur most frequently in middle-aged and older adults. However, this serious condition can also occur in younger patients. The purpose of this study was to compare anterior cruciate ligament (ACL) degeneration and sagittal medial tibial slope in young adults with and without MMPRT. Methods: Eighteen healthy volunteers, 18 young patients (20–49 years of age), and 30 middle-aged and older patients (50–70 years of age) with MMPRT repair were included in the study. Sex, body mass index (BMI), femorotibial angle, ACL degeneration, and medial tibial slope angle were compared among the groups. ACL degeneration and medial tibial slope angle were assessed using magnetic resonance imaging. Results: In the healthy volunteer group, the young patient group, and the older patient group, the medial tibial slopes were 3.5° ± 1.4°, 6.1° ± 2.7°, and 7.2° ± 1.9°, respectively, and the ACL degeneration rates were 5.6%, 38.9%, and 43.3%, respectively. Young patients with MMPRT had significantly steeper medial tibial slopes and ACL degeneration compared to those of the healthy volunteers (P < 0.05). The parameters of young patients were similar to those of older patients with MMPRT. In the multivariate logistic regression analysis, BMI, medial tibial slope, and ACL degeneration were significantly associated with MMPRT in young patients. Conclusion: BMI, steep medial tibial slope, and ACL degeneration contribute to MMPRT development in younger patients. Level of evidence: Level III. [ABSTRACT FROM AUTHOR]

Soft-tissue sarcoma is a rare cancer that accounts for approximately 1% of all malignant tumors. Although they occur in various age groups, soft-tissue sarcomas account for 8% of all malignant tumors developing in adolescents and young adults, suggesting that they are not rare in this age group. This study aimed to evaluate the clinical and pathological characteristics of soft-tissue sarcoma in adolescents and young adults. According to the Bone and Soft-Tissue Tumor Registry in Japan, myxoid liposarcoma is the most common type of soft-tissue sarcoma found in adolescents and young adults; alveolar soft part sarcoma, extraskeletal Ewing sarcoma, epithelioid sarcoma, clear cell sarcoma and synovial sarcoma occur predominantly in this age group among soft-tissue sarcomas. The analysis based on this registry demonstrated that age was not a prognostic factor for poor survival of soft-tissue sarcoma, although the prognosis in adolescents and young adults was better than that in older patients in the US and Scandinavia. Adolescent and young adult patients with soft-tissue sarcoma have age-specific problems, and a multidisciplinary approach to physical, psychological, and social issues is necessary to improve the management of these young patients both during and after treatment. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to evaluate changes in the cleft width, defined as the distance between the lateral edge of the medial tibial plateau and that of the medial meniscus (MM) posterior root, using open magnetic resonance imaging (MRI) in patients with MM posterior root tear (MMPRT). Methods: This study included 25 patients (20 women and 5 men; mean age: 65.2 years) who were diagnosed with MMPRT and underwent pullout repair. Upon coronal imaging, the cleft width was evaluated at the 10° and 90° flexed knee positions. The difference in the cleft width (defined as the cleft width at 90° minus the cleft width at 10°) was also calculated. Upon sagittal imaging, the MM posterior extrusion (MMPE) at 90° was also evaluated. Separate univariate linear regression models were used to determine the association between the time from injury to MRI and radiographic measurements. Results: The mean cleft width at 10° and 90° was 4.9 ± 2.6 mm and 7.4 ± 3.7 mm, respectively; the mean difference in cleft width was 2.5 ± 1.5 mm, and the mean MMPE at 90° was 3.7 ± 1.3 mm. There was a significant difference in cleft width at 10° and 90° (p < 0.001). The time from injury to MRI was significantly associated with the cleft width at 10° (R = 0.42; p = 0.023), cleft width at 90° (R = 0.59; p = 0.002), the difference in the cleft width (R = 0.62; p = 0.008), and MMPE at 90° (R = 0.53; p = 0.008). Conclusion: This study demonstrates that the cleft width is significantly larger during knee flexion than during knee extension. Increased cleft width during knee flexion ("graben" sign) may help diagnose MMPRT, especially in cases where the cleft sign is unclear during knee extension. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: Transtibial pullout repairs using two simple stitches (TSS) and a combination of TSS with posteromedial pullout repair (TSS + PMP) using an all-inside meniscal repair device have been reported previously for the treatment of medial meniscus (MM) posterior root tears. This study aimed to investigate the postoperative clinical outcomes of these techniques including MM extrusion (MME). Methods: Fifty-two patients who underwent transtibial pullout repair were investigated and divided into TSS (n = 27) and TSS + PMP (n = 25) groups. The clinical outcomes were assessed using the Lysholm knee score and Knee Injury and Osteoarthritis Outcome Score 1 year postoperatively and compared between two groups. MME was measured using magnetic resonance imaging at 1 year postoperatively and compared between two groups. Results: A significant improvement in each clinical score was observed in both groups, and no significant difference was seen in clinical outcomes. Moreover, no significant difference in postoperative MME was observed in both groups (TSS and TSS + PMP: 3.5 mm and 3.8 mm, respectively). Though no significant progression of MME was observed in TSS group, a significant progression of it was observed in TSS + PMP group postoperatively. Conclusions: This study demonstrated that both techniques improved clinical outcomes in the short-term postoperative period. However, MME was progressed significantly in TSS + PMP group 1 year postoperatively, which indicated that PMP might not be a useful additional procedure for reducing the postoperative MME. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to determine the efficacy and safety of cement augmentation for internally fixed trochanteric fractures through a systematic review and meta-analysis of randomized controlled trials (RCTs). Methods: We searched the MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov databases to identify RCTs, published until July 2020 that examined the effects of cement augmentation of internal fixation of trochanteric fractures. The primary outcomes were reoperation and Parker Mobility Score, whereas the secondary outcomes were 1-year mortality rate, EuroQol 5 Dimension, fixation failures, and adverse events. We conducted meta-analyses of the outcome measures using the random-effects models. We evaluated the certainty of evidence based on the Cochrane risk-of-bias tool and the Grading of Recommendations, Assessment, Development, and Evaluation approach. Results: We included three RCTs (326 participants). No significant effect was observed in favor of cement augmentation on all these outcomes. The certainty of evidence for fixation failures was very low and that for the other outcomes was low. The overall risk of bias for each outcome was high or of some concern in all included studies. Conclusions: The effect of cement augmentation of internal fixation of trochanteric fractures was uncertain for the clinical outcomes due to the low certainty of evidence. Further RCTs with a low risk of selection bias may present convincing conclusions on the efficacy and safety of cement augmentation. Level of evidence: Level 1 [ABSTRACT FROM AUTHOR]

Purpose: Postoperative radiographs are routinely used to assess fracture reduction following intramedullary nail fixation for pertrochanteric fractures, even though computed tomography (CT) is a superior modality. We aimed to determine the association between reduction quality assessed by CT and rates of reoperation and to evaluate the association of reoperation and reduction quality according to the assessment modality (plain radiographs vs. CT). Methods: A retrospective analysis of 299 consecutive patients treated with intramedullary nail fixation for pertrochanteric fractures was conducted. Fracture reduction measured by postoperative radiographs and CT was categorized as anatomical type, extramedullary type, or intramedullary type. Postoperative data for analysis included reduction status, tip-apex distance (TAD), screw position in the femoral head, sliding distance, and conditions associated with reoperation. Results: Of the 299 patients included with a mean age of 83.1 ± 8.2 years, there were six patients who required reoperation (2.0%). According to the CT assessments, there were 42 intramedullary reductions (14.0%). Patients with a non-intramedullary reduction based on postoperative CT images were significantly more likely to have proper placement of the screw, a reduced TAD, a reduced sliding distance, and a lower reoperation rate than those with an intramedullary reduction (P < 0.05). The reduction quality assessed by postoperative CT was significantly associated with reoperation (95% CI, 1.45–29.31). Conclusions: Intramedullary reduction assessed by CT was associated with reoperation. The reduction quality based on CT findings was more predictive for reoperation than that from plain radiographs. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate the influence of tibial rotation on the postoperative healing status of the medial meniscus (MM) following pullout repair of the MM posterior root tear (MMPRT). Methods: Ninety-one patients (68 women and 23 men; mean age 63.3 ± 8.8 years) who had undergone transtibial pullout repair of MMPRT were enrolled in the study. The tibial external rotation angle (ERA) in each patient was measured postoperatively using computed tomography in the extended knee position. The meniscal healing status following transtibial pullout repair was assessed by second-look arthroscopy (mean postoperative period 12 months) using a previously published scoring system (range 0–10). The association between the ERA and the meniscal healing score was investigated using univariate linear regression models. The ERA cut-off for improved meniscal healing score (≥ 7) was determined using receiver-operating characteristic analysis. Results: The ERA and the meniscal healing score were significantly associated, confirming that increased ERAs were correlated with worse meniscal healing status (R = − 0.28; P < 0.001). The optimum ERA cut-off value was 0.5°, with a sensitivity of 68% and a specificity of 63%. The mean meniscal healing scores were 7.3 and 6.2 among patients with ERAs < 0.5° and those with ERAs ≥ 0.5°, respectively (P < 0.001). Conclusion: This study demonstrated that the ERA was significantly correlated with the postoperative meniscal healing status. Postoperative tibial rotation could be one of the factors affecting postoperative outcomes of pullout repair of MMPRT. Controlling the tibial rotation may possibly improve meniscal healing. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Backgrounds: Medial meniscus (MM) posterior root tear (PRT) results in joint overloading and degenerative changes in the knee, and pullout repair is recommended to prevent subsequent osteoarthritis. Diagnosing MMPRT is sometimes difficult, especially in the case of an incomplete tear. A posterior shiny-corner lesion (PSCL) is reported to be useful for diagnosis, although the association between MMPRT and PSCL is unknown. This study aimed to investigate the properties of PSCL, such as the location, volume, and duration from injury to the time of MRI (duration). We hypothesized that PSCL is observed in the early phase after the MMPRT onset. Methods: T2-weighted fat-suppression magnetic resonance imaging (MRI) was obtained from 55 patients with MMPRT preoperatively. The prevalence of the PSCL; giraffe neck, cleft, and ghost signs; severe MM extrusion (> 3 mm); and the PSCL volume were evaluated. The PSCL lesion elliptical volume (mm3) was calculated by measuring the anteroposterior, transverse, and craniocaudal dimensions. Results: PSCL was observed in 34 (62%) cases. The mean volume of the PSCL was 102.0 mm3. A significantly shorter duration was observed in the PSCL-positive group (5.6 weeks) than that in the PSCL-negative group (40.9 weeks, P < 0.01), although no significant correlation was observed between the PSCL volume and duration. The sensitivity for the MMPRT was 90.5% when the cut-off duration value was 3 weeks and 81.8% when the cut-off value was 8 weeks. Conclusions: MRI examination may detect PSCL if it is performed early following MMPRT onset. Detecting PSCL may be useful in diagnosing MMPRT with high sensitivity. [ABSTRACT FROM AUTHOR]

Objective: It has been reported that levels of soluble CD30 in serum and joint fluid are significantly elevated in patients with rheumatoid arthritis (RA). This study aimed to investigate whether CD30 could be a therapeutic target for RA. Methods: The expression and localization of CD30 were examined by immunohistochemical and double immunofluorescence staining on synovial tissue samples obtained from patients with RA or osteoarthritis (OA) during surgery. Changes in CD30 expression of fibroblast-like synoviocytes (FLS) from RA patients with or without TNFα and IL-1β stimulation were examined by the polymerase chain reaction (PCR) and flow cytometry. Collagen antibody-induced arthritis (CAIA) was created in DBA/1 mice, and the therapeutic effect of brentuximab vedotin (BV) was examined by clinical score, histological findings and measurement of serum levels of SAA, IL-6, and TNFα. Results: CD30 expression was significantly higher in samples from patients with RA than from those with OA. Double immunofluorescence showed a low rate of co-localization of CD30 with CD20 or CD90, but a high rate of co-localization of CD30 and CD138. CD30 mRNA expression was upregulated 11.7-fold in FLS following stimulation by inflammatory cytokines. The clinical scores of CAIA mice were significantly lower following both BV treatments, however, the histological scores of CAIA mice were significantly lower only following treatment with high dose BV (70 mg/kg). Conclusions: CD30 was expressed on immunocompetent cells in synovial tissue from RA patients and in cytokine-stimulated FLS in vitro. High dose BV (70 mg/kg) showed significant therapeutic effects in ameliorating inflammation and joint destruction in CAIA mice, but low dose BV (30 mg/kg) was insufficient. [ABSTRACT FROM AUTHOR]

Purpose: The volume of medial meniscus (MM) extrusion at 10° and 90° knee flexions using three-dimensional (3D) magnetic resonance imaging (MRI) and assessed relevant clinical outcomes at 1-year follow-up were evaluated. Methods: Twenty-four patients who underwent MM posterior root repair were retrospectively reviewed. At 10° and 90° knee flexions, the meniscal extrusion distance and volume were measured using 3D meniscus models constructed by SYNAPSE VINCENT®. The correlation between Knee Injury and Osteoarthritis Outcome Score, Lysholm, International Knee Documentation Committee scores, Tegner activity, and pain visual analog scales and changes in MM extrusion were assessed. Results: No significant differences in the MM medial extrusion were observed between 10° and 90° knee flexions postoperatively. MM posterior extrusion (MMPE) decreased significantly at 10° and 90° knee flexions postoperatively. At 90° knee flexion, the meniscus volume at the intra-tibial surface increased at 3 and 12 months postoperatively. The MM extrusion volume increased slightly at 10° knee flexion; however, the volume decreased significantly at 90° knee flexion postoperatively. The change in MMPE significantly correlated with clinical scores. All 12-month clinical scores were significantly improved compared to preoperative scores. Conclusions: The progression of meniscus posterior extrusion and reduction of its volume at 90° knee flexion can be suppressed by MM posterior root repair. Postoperative clinical scores correlated with reductions of the posterior extrusion. Regarding clinical relevance, the dynamic stability of the meniscus can be maintained by MM posterior root repair, which is an effective therapeutic method for improving its clinical status. Level of evidence: Level IV. [ABSTRACT FROM AUTHOR]

Purpose: A medial meniscus posterior root tear results in the loss of meniscal circumferential hoop stress and causes a pathological posteromedial extrusion of the medial meniscus. Although creating a tibial tunnel in the anatomic place improves postoperative medial meniscus posterior extrusion, no studies have evaluated the relationship between tibial tunnel position and clinical outcomes. This study aimed to evaluate how tibial tunnel positioning of medial meniscus posterior root pullout repair affects meniscal healing status and clinical outcomes. Methods: Sixty-two patients with 64 medial meniscus posterior root tears (mean age 62.8 ± 7.9 years) who had undergone pullout repairs and second-look arthroscopies were included. All 62 patients were Lachman test negative. Three-dimensional computed tomography images of the tibial surface were evaluated using a rectangular measurement grid to assess the tibial tunnel centre and medial meniscus posterior root attachment centre. Spearman's rank correlation analysis was undertaken to determine displacement distance from the medial meniscus posterior root attachment centre to the tibial tunnel centre and a meniscal healing score, as well as clinical outcomes at 1 year post-repair. Results: Tibial tunnel centres were located more anteriorly and medially than the medial meniscus posterior root attachment centre (mean distance 5.0 ± 2.2 mm). The mean meniscal healing score was 6.7 ± 1.8 of 10 possible points. The 1-year postoperative clinical scores showed significant improvement compared with preoperative scores for all the items. There was a significant negative correlation in the absolute distance between the medial meniscus posterior root attachment centre and the tibial tunnel centre with the meniscal healing score (ρ = − 0.39, p = 0.002). Furthermore, there were significant positive correlations between the distance between the medial meniscus posterior root attachment centre and the tibial tunnel centre in the mediolateral direction and patient-based clinical outcomes (ρ = 0.25–0.43, p < 0.05). Conclusion: Accurate placement of a tibial tunnel, especially in the mediolateral direction, significantly improved meniscal healing and clinical outcomes at 1 year following medial meniscus posterior root repair. Surgeons should create a medial meniscus posterior root tibial tunnel at the anatomic attachment with particular attention to the mediolateral position. Level of evidence: Level IV. [ABSTRACT FROM AUTHOR]

Purpose: To assess the effects of transtibial pullout repair for medial meniscus posterior root tears (MMPRTs) among patients with early osteoarthritis of the knee as measured by the meniscus healing score and to determine whether the meniscus healing score correlates with the International Cartilage Repair Society (ICRS) grade progression. Methods: Forty-seven patients with mild osteoarthritic knees (Kellgren–Lawrence grade ≤ 2 and varus alignment < 5°) who underwent transtibial pullout repair less than 3 months after MMPRT onset were assessed. The association between meniscus healing scores at 1 year postoperatively and cartilage damage of the medial compartment (medial femoral condyle [MFC] and medial tibial plateau [MTP]) were evaluated. The MFC was divided into six zones (A to F) and the MTP into two zones (G and H). The mean ICRS grade for each zone was compared between the primary surgery and second-look arthroscopy. The correlation between cartilage damage and meniscus healing status at the time of second-look arthroscopy in each zone was analysed. Results: The mean time interval from injury to surgery was 63 days, and all clinical scores showed significant improvement. There were no significant differences in the extent of cartilage damage in areas B, C, E, or F (n.s.) for MFC or in areas G and H (n.s.) for MTP. The meniscus healing score and cartilage damage were correlated in the loading areas (B, C, E, and H; − 0.53, − 0.45, − 0.33, and − 0.38, respectively; p < 0.05). Conclusion: Transtibial pullout repair of MMPRTs among patients with mild osteoarthritic knees improved the clinical outcomes and showed a negative correlation between high meniscus healing scores and ICRS grades in the medial compartment loading area. This study suggests that early surgery should be undertaken for patients with mild osteoarthritic knee who develop MMPRTs. Level of evidence: Level IV. [ABSTRACT FROM AUTHOR]

Background: Osteosarcoma (OS) is a malignant bone tumor primarily affecting children and adolescents. The prognosis of chemotherapy-refractory OS patients is poor. We developed a tumor suppressor p53–expressing oncolytic adenovirus (OBP-702) that exhibits antitumor effects against human OS cells. Here, we demonstrate the chemosensitizing effect of OBP-702 in human OS cells. Materials and methods: The in vitro and in vivo antitumor activities of doxorubicin (DOX) and OBP-702 were assessed using parental and DOX-resistant OS cells (U2OS, MNNG/HOS) and a DOX-resistant MNNG/HOS xenograft tumor model. Results: DOX-resistant OS cells exhibited high multidrug resistant 1 (MDR1) expression, which was suppressed by OBP-702 or MDR1 siRNA, resulting in enhanced DOX-induced apoptosis. Compared to monotherapy, OBP-702 and DOX combination therapy significantly suppressed tumor growth in the DOX-resistant MNNG/HOS xenograft tumor model. Conclusion: Our results suggest that MDR1 is an attractive therapeutic target for chemoresistant OS. Tumor-specific virotherapy is thus a promising strategy for reversing chemoresistance in OS patients via suppression of MDR1 expression. [ABSTRACT FROM AUTHOR]

Purpose: Medial meniscus posterior root tears (MMPRTs) can cause severe medial extrusion of the medial meniscus (MMME) and the progression of knee degenerative changes, inducing a high signal intensity of the meniscus on magnetic resonance imaging (MRI). Although MMME and intrameniscal signal intensity (IMSI) reportedly decreased within 3 months after MMPRT repair, no previous studies have reported these changes after a 1-year follow-up. This study aimed to investigate the 1-year postoperative changes in MMME and IMSI on MRI after using different suture techniques. Methods: Overall, 33 patients with MMPRT were evaluated, 22 underwent FasT-Fix-dependent modified Mason–Allen suture (F-MMA) repair, and 11 underwent two simple stitches (TSS) repair. MRI examinations were performed preoperatively and 1 year postoperatively. MMME and IMSI were determined using MRI. Results: A significant decrease in postoperative MMME was observed in the TSS group (4.1 ± 1.0) relative to that in the F-MMA group (5.1 ± 1.4, P = 0.03). A significant decrease in postoperative IMSI (0.75 ± 0.14) was observed relative to preoperative IMSI in the TSS group (P < 0.01), whereas postoperative IMSI (0.94 ± 0.25) was similar to preoperative IMSI in the F-MMA group (P = 0.06). Furthermore, a significant decrease in postoperative IMSI was observed in the TSS group relative to that in the F-MMA group (P < 0.01). Conclusions: The most important finding of this study is that TSS repair yielded a greater decrease in MMME and IMSI than F-MMA repair in patients with MMPRT. These results suggest that TSS repair is more useful for restoring loading stress to the posterior horn of the medial meniscus. [ABSTRACT FROM AUTHOR]

Background: A prospective cohort study was conducted to determine the incidence and risk factors of symptomatic venous thromboembolism (sVTE) during the perioperative period in patients with malignant bone and soft tissue tumors. Methods: Patients with newly diagnosed primary malignant bone and soft tissue tumors for whom definitive surgery was planned were consecutively registered among 27 tertiary hospitals specializing in musculoskeletal oncology. Clinicopathological information on each patient was collected prospectively, and careful follow-up was conducted for 6 months after surgery. The study endpoint was the occurrence of sVTE, including deep vein thrombosis (DVT) and pulmonary embolism (PE). Results: Eleven of 929 patients developed sVTE, including 8 patients with DVT, 2 with PE, and 1 with both, making the incidence of sVTE 1.18%. The median time until the development of sVTE after tumor resection was 11 days, ranging from − 7 to 95 days. Multiple logistic regression analyses revealed that ischemic heart disease as a comorbidity, maximum tumor diameter exceeding 8 cm, and elevated preoperative platelet count were independent risk factors for sVTE. Conclusions: The incidence of sVTE in this series of patients with bone and soft tissue sarcomas was 1.18%, which was relatively lower than in previous retrospective studies. We identified the risk factors for sVTE specific to patients with malignant bone and soft tissue tumors, and these included ischemic heart disease, tumor size, and elevation of the preoperative platelet count. [ABSTRACT FROM AUTHOR]

Introduction: Radiation-induced pathological fractures show high nonunion and infection rates. Successful treatment of postoperative infections of these fractures without limb amputation is extremely rare.Methods: We report two cases of postoperative infection of pathological femoral fracture after radiation therapy for soft tissue tumors. Considering the poor condition of the irradiated site, a two-staged operation was selected to create the optimal situation for bone union. The treatment involved the Masquelet technique, latissimus dorsi (LD) flap, and a free vascularized fibula graft (FVFG). In the first stage, we drastically resected the necrotic bone and the surrounding infected tissue and placed antibiotic polymethylmethacrylate space on the bone gap according to the Masquelet technique. Next, we used an Ilizarov external fixator as a temporizing stabilizer and performed the LD flap. Six weeks later, in the second stage, we changed the external fixation to plate fixation; packed the artificial bone (β-TCP) and autograft bone to the induced membrane; and performed FVFG on the other side of the plate. As postoperative therapy, toe touch was allowed immediately, and partial weight bearing was started 2 months after second surgery.Results: Both patients achieved bone union and were able to walk without postoperative complications. At the 2-year follow-up, there was no recurrence of infection.Conclusion: Our treatment is effective for controlling postoperative infection of radiation-induced pathological fracture. [ABSTRACT FROM AUTHOR]

Immune checkpoint inhibitors including anti-programmed cell death 1 (PD-1) antibody have recently improved clinical outcome in certain cancer patients; however, osteosarcoma (OS) patients are refractory to PD-1 blockade. Oncolytic virotherapy has emerged as novel immunogenic therapy to augment antitumor immune response. We developed a telomerase-specific replication-competent oncolytic adenovirus OBP-502 that induces lytic cell death via binding to integrins. In this study, we assessed the combined effect of PD-1 blockade and OBP-502 in OS cells. The expression of coxsackie and adenovirus receptor (CAR), integrins αvβ3 and αvβ5, and programmed cell death ligand 1 (PD-L1) was analyzed in two murine OS cells (K7M2, NHOS). The cytopathic activity of OBP-502 in both cells was analyzed using the XTT assay. OBP-502-induced immunogenic cell death was assessed by analyzing the level of extracellular ATP and high-mobility group box protein B1 (HMGB1). Subcutaneous tumor models for K7M2 and NHOS cells were used to evaluate the antitumor effect and number of tumor-infiltrating CD8+ cells in combination therapy. K7M2 and NHOS cells showed high expression of integrins αvβ3 and αvβ5, but not CAR. OBP-502 significantly suppressed the viability of both cells, in which PD-L1 expression and the release of ATP and HMGB1 were significantly increased. Intratumoral injection of OBP-502 significantly augmented the efficacy of PD-1 blockade on subcutaneous K2M2 and NHOS tumor models via enhancement of tumor-infiltrating CD8+ T cells. Our results suggest that telomerase-specific oncolytic virotherapy is a promising antitumor strategy to promote the efficacy of PD-1 blockade in OS. [ABSTRACT FROM AUTHOR]

Purpose: Contralateral medial meniscus posterior root tear (MMPRT) can sometimes occur after primary surgeries for MMPRT and lead to unsatisfactory outcomes. The incidence rate and risk factors for contralateral MMPRT have not been well investigated, despite their clinical importance. Therefore, the incidence and predictors of bilateral MMPRT were aimed to be evaluated. Methods: Fourteen patients with bilateral MMPRT (group B) and 169 patients with unilateral MMPRT (group U) were enrolled in this study. Sex, age, body mass index, time between injury and surgery, and medial tibial slope angle (MTSA) were compared between the groups. MTSA was measured using lateral radiographs. Results: The incidence rate of bilateral MMPRT was 6.2% among all patients with MMPRTs. Multivariate logistic regression analysis showed that a prolonged time between injury and surgery (odds ratio [OR], 1.0; 95% confidence interval [CI] 1.00–1.01; P < 0.05) and steeper MTSA (OR, 1.85; 95% CI 1.21–2.64; P < 0.01) were significantly associated with the development of bilateral MMPRT. Receiver operating characteristic curve analysis showed that MTSA > 10.0° was associated with bilateral MMPRT, with a sensitivity of 93% and specificity of 69%. Conclusion: A longer time between injury and surgery and steeper MTSA were risk factors for the development of bilateral MMPRT. Surgeons need to pay close attention to the contralateral knee in addition to the primary injured knees when treating knees with steep MTSA. Besides, early meniscal repair of primary MMPRT would be important to prevent the events of contralateral MMPRT. Level of evidence: III. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate the influence of tibial tunnel position in pullout repair for a medial meniscus (MM) posterior root tear (MMPRT) on postoperative MM extrusion. Methods: Thirty patients (median age 63 years, range 35–72 years) who underwent transtibial pullout repairs for MMPRTs were included. Three-dimensional computed tomography images of the tibial surface were evaluated using a rectangular measurement grid for assessment of tibial tunnel position and MM posterior root attachment. Preoperative and postoperative MM medial extrusion (MMME) and posterior extrusion (MMPE) at 10° and 90° knee flexion were measured using open magnetic resonance imaging. Results: Tibial tunnel centers were located more anteriorly and more medially than the anatomic center (median distance 5.8 mm, range 0–9.3 mm). The postoperative MMPE at 90° knee flexion was significantly reduced after pullout repair, although there was no significant reduction in MMME or MMPE at 10° knee flexion after surgery. In the correlation analysis of the displacement between the anatomic center to the tibial tunnel center and improvements in MMME, and MMPE at 10° and 90° knee flexion, there was a significant positive correlation between percentage distance and improvement of MMPE at 90° knee flexion. Conclusion: This study demonstrated that the nearer the tibial tunnel position to the anatomic attachment of the MM posterior root, the more effective the reduction in MMPE at 90° knee flexion. Our results emphasize that an anatomic tibial tunnel should be created in the MM posterior root to improve the postoperative MMPE and protect the articular cartilage in a knee flexion position. Placement of an anatomic tibial tunnel significantly improves the MMPE at 90° of knee flexion after MM posterior root pullout repair. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Deep tendon reflexes are one of the main components of the clinical nervous system examinations. These assessments are inexpensive and quick. However, evaluation can be subjective and qualitative. This study aimed to objectively evaluate hyperreflexia of the patellar tendon reflex using portable mechanomyography (MMG) and electromyography (EMG) devices. This study included 10 preoperative patients (20 legs) who had a pathology that could cause bilateral patellar tendon hyperreflexia and 12 healthy volunteers (24 legs) with no prior history of neurological disorders. We attached MMG/EMG sensors onto the quadriceps and tapped the patellar tendon with maximal and constant force. Our results showed a significantly high amplitude of the root mean square (RMS) and low frequency of the mean power frequency (MPF) in the rectus femoris, vastus medialis, and vastus lateralis muscles in both EMG and MMG with both maximal and constant force. Especially in the patients with cervical and thoracic myelopathy, the receiver operating characteristic (ROC) curve for diagnosing hyperreflexia of the patellar tendon showed a moderate to very high area under the curve for all EMG–RMS, EMG–MPF, MMG–RMS, and MMG–MPF values. The use of EMG and MMG for objectively quantifying the patellar tendon reflex is simple and desirable for future clinical applications and could help diagnose neurological disorders. [ABSTRACT FROM AUTHOR]

Purpose: Bone morphological factors are important for menisci. Their association with medial meniscus posterior root tears, however, has not yet been studied. This study aimed to compare sagittal medial tibial slope and medial tibial plateau depth between knees with and without medial meniscus posterior root tears. Methods: Nine healthy volunteers, 24 patients who underwent anterior cruciate ligament reconstruction, and 36 patients who underwent medial meniscus posterior root pullout repair were included. Magnetic resonance imaging examinations were performed in the 10°-knee-flexed position. The medial tibial slope and medial tibial plateau depth were compared among the groups. Results: In healthy volunteers, the anterior cruciate ligament reconstruction group, and the medial meniscus posterior root tear group, the medial tibial slopes were 3.5° ± 1.4°, 4.0° ± 1.9°, and 7.2° ± 1.9°, respectively, and the medial tibial plateau depths were 2.1 ± 0.7 mm, 2.2 ± 0.6 mm, and 1.2 ± 0.5 mm, respectively. Patients with medial meniscus posterior root tears had a significantly steep medial tibial slope and shallow medial tibial plateau concavity compared to those of healthy volunteers (P < 0.01) and the anterior cruciate ligament group (P < 0.01). In the multivariate logistic regression analysis, body mass index, medial tibial slope, and medial tibial plateau depth were significantly associated with medial meniscus posterior root tears. Conclusions: A steep posterior slope and a shallow concave shape of the medial tibial plateau are risk factors for medial meniscus posterior root tear. Level of evidence: Level III: Case–control study. [ABSTRACT FROM AUTHOR]

Unidirectional porous hydroxyapatite (UDPHAp) was developed as an excellent scaffold with unidirectional pores oriented in the horizontal direction with interpore connections. The purpose of this study was to assess radiographic changes and clinical outcomes and complications following UDPHAp implantation to treat benign bone tumors. We retrospectively analyzed 44 patients treated with intralesional resection and UDPHAp implantation for benign bone tumors between 2010 and 2015. Clinical and radiographic findings were evaluated postoperatively at regular follow-up visits. The mean follow-up was 49 months. Radiographic changes were classified into five stages based on bone formation in the implanted UDPHAp according to Tamai's classification. All patients showed excellent bone formation inside and around implanted UDPHAp. Absorption of UDPHAp and bone marrow cavity remodeling was identified in 20 patients at a mean of 17 months postoperatively, and was significantly more common in young patients. Preoperative cortical thinning was completely regenerated in 26 of 31 patients on average 10 months after surgery. There were no cases of delayed wound healing, postoperative infection, or allergic reaction related to implanted UDPHAp. UDPHAp is a useful bone-filling substitute for treating benign bone tumor, and the use of this material has a low complication rate. [ABSTRACT FROM AUTHOR]

Purpose: Transtibial repair of a medial meniscus posterior root tear (MMPRT) can improve clinical outcomes, although meniscal extrusion remains. However, few studies have investigated the volume of meniscal extrusion. This study aimed to evaluate the effect of transtibial repair in reducing the volume using three-dimensional (3D) magnetic resonance imaging, at 10° and 90° knee flexion. Methods: Twenty patients with MMPRTs and 16 volunteers with normal knees participated. The 3D models of meniscus were constructed using SYNAPSE VINCENT®. The meniscal extrusion and its volume were measured at 10° and 90° knee flexion. Differences between the pre- and postoperative examinations were assessed using the Wilcoxon signed-rank test. The postoperative parameters were compared to those in patients with normal knees. Results: There were no significant pre- and postoperative differences in any parameter at 10° knee flexion. At 90° knee flexion, the posterior extrusion and its meniscal volume were decreased significantly after transtibial repair (p < 0.05), even though these parameters were larger than in the normal knees. On the other hand, intra-articular meniscal volume calculated by the extrusion volume was increased to the level of the normal knee. Conclusions: This study demonstrated that transtibial repairs improved the intra-articular/intra-tibial surface volume of the medial meniscus by reducing the posteromedial extrusion during knee flexion. This 3D analysis is clinically relevant in evaluating that, while transtibial root repair has a limited ability to reduce meniscal extrusion, it can restore the functional volume of the medial meniscus which contributes to the shock absorber postoperatively. Level of evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: To investigate changes in meniscal extrusion during knee flexion before and after pullout fixation for medial meniscus posterior root tear (MMPRT) and determine whether these changes correlate with articular cartilage degeneration and short-term clinical outcomes.Methods: Twenty-two patients (mean age 58.4 ± 8.2 years) diagnosed with type II MMPRT underwent open magnetic resonance imaging preoperatively, 3 months after transtibial fixation and at 12 months after surgery, when second-look arthroscopy was also performed. The medial meniscus medial extrusion (MMME) and the medial meniscus posterior extrusion (MMPE) were measured at knee 10° and 90° flexion at which medial meniscus (MM) posterior translation was also calculated. Articular cartilage degeneration was assessed using International Cartilage Research Society grade at primary surgery and second-look arthroscopy. Clinical evaluations included Knee Injury and Osteoarthritis Outcome Score, International Knee Documentation Committee subjective knee evaluation form, Lysholm score, Tegner activity level scale, and pain visual analogue scale.Results: MMPE at 10° knee flexion was higher 12 months postoperatively than preoperatively (4.8 ± 1.5 vs. 3.5 ± 1.2, p = 0.01). MMPE at 90° knee flexion and MM posterior translation were smaller 12 months postoperatively than preoperatively (3.5 ± 1.1 vs. 4.6 ± 1.3, 7.2 ± 1.7 vs. 8.9 ± 2.0, p < 0.01). Articular cartilage degeneration of medial femoral condyle correlated with MMME in knee extension (r = 0.5, p = 0.04). All clinical scores significantly improved 12 months postoperatively. However, correlations of all clinical scores against decreased MMPE and increased MMME were not detected.Conclusions: MMPRT transtibial fixation suppressed the progression of MMPE and cartilage degeneration and progressed MMME minimally in knee flexion position at 1 year. However, in the knee extension position, MMME progressed and correlated with cartilage degeneration of medial femoral condyle. MMPRT transtibial fixation contributes to the dynamic stability of the MM in the knee flexion position.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to clarify the advantages of three-dimensional (3D) magnetic resonance imaging (MRI) over two-dimensional (2D) MRI in measuring the size of the medial meniscus (MM) and to analyse the volumes of MM and the extruded meniscus in patients with MM posterior root tear (MMPRT), at 10° and 90° knee flexion.Methods: This study included 17 patients with MMPRTs and 15 volunteers with uninjured knees. The MMs were manually segmented for 3D reconstruction; thereafter, the extruded part separated from the tibial edge was determined. The length, width, height, and extrusion of MM were measured by the 2D and 3D methods, and compared. The MM volume, extruded meniscus volume, and their ratio were also calculated using 3D analysis software in the two groups.Results: The estimated length and posterior height of MM were larger with 3D MRI than with 2D MRI measurements. The MM volume was significantly greater in MMPRT knees than in normal knees, with increasing MM height. In MMPRT knees, the mean volume of the extruded meniscus and its ratio significantly increased by 304 mm3 (p = 0.02) and 9.1% (p < 0.01), respectively, during knee flexion.Conclusions: This study demonstrated that 3D MRI could estimate the precise MM size and that MMPRT caused swelling of the meniscus due to the increased thickness in the posteromedial part. The clinical significance of this study lies in its 3D evaluation of MM volume, which should help the surgeon understand the biomechanical failure of MM function and improve MMPRT repair technique.Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

Objectives: To identify the diagnostic performance of magnetic resonance imaging (MRI) in the knee-flexed position for the detection of meniscal ramp lesions in patients with anterior cruciate ligament tears. Materials and methods: Forty-three patients (mean age 24.5 ± 9.5 years; 21 males, 22 females) with an arthroscopically proven anterior cruciate ligament tear were included in this retrospective study. The presence of the following two important features on MRI was recorded: irregularity of the medial meniscus at the posterior margin, and complete fluid filling between the posterior horn of the medial meniscus and the capsule margin. Findings obtained in arthroscopy served as the reference standard. The diagnostic sensitivity, specificity, and inter-observer agreement were calculated. Results: Sixteen ramp lesions were noted on arthroscopy (37.2%). With an irregularity of the medial meniscus at the posterior margin on MRI, the sensitivity and specificity were 87.5 and 59.3% at 10° knee flexion and 93.8 and 85.2% at 90° flexion, respectively. The complete fluid filling sign on MRI showed sensitivity and specificity of 31.3 and 100% at 10° knee flexion and 87.5 and 100% at 90° flexion, respectively. The concordance between the two observers for the two MRI features was very good (k = 0.70–0.88). Conclusion: MRI with the knee in the flexed position improves the diagnostic performance of the detection of meniscal ramp lesions compared with MRI with the knee in the extended position. [ABSTRACT FROM AUTHOR]

Background: Two types of repair techniques, FasT-Fix modified Mason–Allen (F-MMA) and two simple stitches (TSS), for the treatment of a medial meniscus posterior root tear (MMPRT) were previously reported. However, whether these techniques could prevent postoperative medial meniscus extrusion (MME) progression is unknown. This study investigated and compared postoperative MME of the two repair techniques. Methods: Forty-seven knees that had undergone pullout repair for MMPRT were retrospectively reviewed. These knees were divided into two groups as follows: In 26 knees, MMPRT was treated using the F-MMA technique and fixed with the knee flexed at 45° and 20 N of tension [F-MMA (45°–20 N) group], and in 21 knees, MMPRT was treated using the TSS technique and fixed with the knee flexed at 20° and 30 N of tension [TSS (20°–30 N) group]. The medial meniscus body width (MMBW), absolute MME (aMME), and relative MME (rMME = absolute MME/MMBW) were measured and compared using magnetic resonance imaging 3 months postoperatively. The Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales for clinical outcomes were compared between the two groups at 6 months postoperatively. Results: At 3 months postoperatively, the aMME and rMME significantly decreased in the TSS (20°–30 N) compared to the F-MMA (45°–20 N) group. The TSS (20°–30 N) group had better KOOS subscale scores than the F-MMA (45°–20 N) group at 6 months postoperatively. Conclusions: The TSS technique with appropriate tibial fixation can decrease MME soon after surgery. This may prevent osteoarthritis progression and improve clinical outcomes. [ABSTRACT FROM AUTHOR]

Infiltrative tumor growth into adjacent soft tissues is a major cause of the frequent recurrence and tumor-related death of myxofibrosarcoma (MFS), but no useful biomarkers reflecting tumor burden and infiltrative growth are available. While emerging evidence suggests a diagnostic and functional role of extracellular/circulating microRNA (miRNA) in various malignant diseases, their significance in MFS patients remains unknown. Global miRNA profiling identified four upregulated miRNAs in MFS patient sera and culture media of MFS cells. Among these, serum miR-1260b level was significantly upregulated in patient serum discriminating from healthy individuals and closely correlated with clinical status and tumor dynamics in MFS-bearing mice. In addition, high miR-1260b expression in serum was correlated with radiological tail-like patterns, characteristic of the infiltrative MFS. The extracellular miR-1260b was embedded in tumor-derived extracellular vesicles (EVs) and promoted cellular invasion of MFS through the downregulation of PCDH9 in the adjacent normal fibroblasts. Collectively, circulating miR-1260b expression may represent a novel diagnostic target for tumor monitoring of this highly aggressive sarcoma. Moreover, EV-miR-1260b could act as a transfer messenger to adjacent cells and mediate the infiltrative growth of MFS, providing new insights into the mechanism of infiltrative nature via crosstalk between tumor cells and their microenvironment. [ABSTRACT FROM AUTHOR]

Purpose: In total knee arthroplasty (TKA), it is important to obtain an appropriate flexion-extension gap. The extension gap is expanded by posteromedial vertical capsulotomy (PMVC). This study aimed to evaluate the increase in the extension gap by PMVC using a navigation system.Methods: In posterior stabilized (PS)-type TKA, PMVC was performed in 37 knees. The medial extension gap at 0° and flexion gap at 90° flexion of the knee joint using the navigation system before and after PMVC were measured.Results: The extension gap before the PMVC was 5.3 ± 2.9 mm. After PMVC, the extension gap had significantly increased to 8.0 ± 2.8 mm (p < 0.001). In addition, the flexion gap was 8.1 ± 2.7 mm before the PMVC, but it was 8.7 ± 2.8 mm after the PMVC, and the flexion gap was not enlarged (n.s.).Conclusion: In PS-type TKA, it is possible to obtain selective expansion of about 2.7 mm of the extension gap by PMVC. Therefore, gap balance can be acquired by soft-tissue treatment while preserving the bone. The PMVC was a useful method for acquiring gap balance and preserving the bone stock.Level Of Evidence: IV. [ABSTRACT FROM AUTHOR]

Background: Postoperative thrombosis of the external iliac artery (EIA) following open reduction and internal fixation for acetabular fracture is extremely rare.Purpose: To report a patient with EIA thrombosis following open reduction and internal fixation using the modified ilioinguinal approach for acetabular fractures.Study Design: This is a case report of a 69-year-old male with a left acetabular fracture who was treated surgically.Methods: A 69-year-old male presented with left hip pain after a 1.5-m fall. Radiographs revealed left acetabular anterior wall and posterior hemitransverse fractures with dome impaction. Computed tomography (CT) showed atherosclerotic changes in many arteries. Open reduction and internal fixation were performed using the modified ilioinguinal approach. Adhesion around the external iliac vessels was severe, and the external iliac vein (EIV) ruptured during exposure. After EIV repair, anatomical reduction was achieved and the fracture was fixed using a reconstruction plate. Nine hours after surgery, the left lower limb showed acute ischemic symptoms. Contrast-enhanced CT indicated complete occlusion of the left EIA. The patient was immediately taken for a thrombectomy via EIA cut-down using a Fogarty catheter. Postoperatively, he had palpable dorsalis pedis and posterior tibial pulses; however, post-reperfusion compartment syndrome developed. Fasciotomy of the left leg was performed.Results: At the 2-year and 4-month follow-up, he was pain-free in his hip and leg. Although he was walking with a cane, activity was limited due to a mild foot drop.Conclusions: It is very important for surgeons to consider EIA thrombosis as a potential complication following open reduction and internal fixation. In this case, EIA thrombosis could be explained by preoperative atherosclerotic changes and intraoperative vascular handling procedures. Preoperative screening and management, and meticulous surgical procedures are necessary for patients with a high risk of thrombosis. [ABSTRACT FROM AUTHOR]

The prone position is usually not selected for pulmonary resection. The intraoperative body position is an important issue in surgery for non-small cell lung cancer invading the spine because the standard intraoperative body position for a vertebrectomy is a prone position, while that for a pulmonary resection is a lateral decubitus position. Intraoperative changes in body position can cause several complications. Using an O-arm with a navigation system, a partial vertebrectomy was completed with the patient in a prone position thanks to the recognition of accurate surgical margins in the vertebral body; then, without changing the patient's body position, a lobectomy with systemic lymph node dissection was performed via a posterior approach. Especially for procedures requiring a wide resection of the chest wall, a prone position can be selected for a lobectomy with systemic lymph node dissection via a posterior approach without any significant difficulties. [ABSTRACT FROM AUTHOR]

Background: To reveal trends in bone microarchitectural parameters with increasing spatial resolution on ultra-high-resolution computed tomography (UHRCT) in vivo and to compare its performance with that of conventional-resolution CT (CRCT) and micro-CT ex vivo. Methods: We retrospectively assessed 5 tiger vertebrae ex vivo and 16 human tibiae in vivo. Seven-pattern and four-pattern resolution imaging were performed on tiger vertebra using CRCT, UHRCT, and micro-CT, and on human tibiae using UHRCT. We measured six microarchitectural parameters: volumetric bone mineral density (vBMD), trabecular bone volume fraction (bone volume/total volume, BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular separation (Tb.Sp), and connectivity density (ConnD). Comparisons between different imaging resolutions were performed using Tukey or Dunnett T3 test. Results: The vBMD, BV/TV, Tb.N, and ConnD parameters showed an increasing trend, while Tb.Sp showed a decreasing trend both ex vivo and in vivo. Ex vivo, UHRCT at the two highest resolutions (1024- and 2048-matrix imaging with 0.25-mm slice thickness) and CRCT showed significant differences (p ≤ 0.047) in vBMD (51.4 mg/cm3 and 63.5 mg/cm3versus 20.8 mg/cm3), BV/TV (26.5% and 29.5% versus 13.8 %), Tb.N (1.3 l/mm and 1.48 l/mm versus 0.47 l/mm), and ConnD (0.52 l/mm3 and 0.74 l/mm3versus 0.02 l/mm3, respectively). In vivo, the 512- and 1024-matrix imaging with 0.25-mm slice thickness showed significant differences in Tb.N (0.38 l/mm versus 0.67 l/mm, respectively) and ConnD (0.06 l/mm3versus 0.22 l/mm3, respectively). Conclusions: We observed characteristic trends in microarchitectural parameters and demonstrated the potential utility of applying UHRCT for microarchitectural analysis. [ABSTRACT FROM AUTHOR]

Introduction: The effect of tranexamic acid (TXA) on the incidence of venous thromboembolic events (VTEs) in total knee arthroplasty (TKA) as assessed by contrast-enhanced computed tomography (CT) is unclear. Thus, we investigated the efficacy and safety profiles of TXA administration during TKA. We hypothesised that intra-articular 1 g TXA administration would have a sufficient effect on the reduction of blood loss and transfusion rates without increasing VTE risk. Materials and methods: We retrospectively analysed 86 patients who underwent primary TKA from January 2014 to September 2017. The study comprised control (n = 45) and TXA (n = 41) groups. All patients underwent navigation-assisted TKA via the medial parapatellar approach. In those who received TXA, 1 g of intra-articular TXA was injected via a drain immediately following wound closure. The drain was clamped for 2 h and then reopened. Contrast-enhanced CT was performed 5–6 days after surgery to detect deep venous thrombosis (DVT) and pulmonary embolism (PE). Blood loss was calculated using the haemoglobin balance method. Results: The mean postoperative volume of blood loss was 900 ± 296 mL vs 1216 ± 445 mL in the TXA vs control group (p < 0.01). Allogeneic blood transfusion was required for 0 (0%) vs 6 (13.3%) patients in the TXA vs control group (p = 0.013). There were no significant inter-group differences regarding DVT and PE incidence (p > 0.05). No case of symptomatic PE occurred. Conclusions: This study demonstrated that intra-articular 1 g TXA administration during TKA is safe and effective for reducing blood loss and blood transfusion without increasing VTE risk. [ABSTRACT FROM AUTHOR]

The medial meniscus (MM) posterior root has important functions in preventing an excessive loading stress during knee motion and degeneration of the articular cartilage. Although the transtibial pullout repair has become the gold standard for MM posterior root tears (MMPRTs), MM extrusion remains. In addition, during knee extension to deep flexion, the MM posterior segment in the MMPRT knee has been shown to translate toward the posteromedial direction, causing a notable MM posterior extrusion. Thus, the reduction in the MM posteromedial extrusion is one of the important postoperative outcomes to restore the meniscal function and eventually prevent the progression of knee osteoarthritis. The present technical note describes an arthroscopic technique addition to the pullout repair, in which an all-inside suture is inserted into the posteromedial part of the MM to reduce the MM posteromedial extrusion. [ABSTRACT FROM AUTHOR]