Incisura tangent method to determine the transsyndesmotic axis for syndesmotic fixation.

BACKGROUND: Clamping along the transsyndesmotic (TS) axis decreases the risk of malreduction when reducing syndesmotic diastasis. We aimed to measure the difference between the TS axis and the axis determined by the newly proposed fluoroscopic incisura tangent (IT) method. The measurements were compared to those between the TS axis and those based on the center-center (CC) and talar dome lateral (TL) methods. METHODS: We analyzed computed tomographic images of 43 normal ankles. The IT view was simulated using a digitally reconstructed radiograph, in which the anterior and posterior fibular incisura tubercles overlapped on the internally rotated anteroposterior view. The interaxis angle between the TS and the axes determined by the IT method was measured on the axial computed tomographic image corresponding to the radiographic image. The same procedure was repeated using the CC and TL methods. The measured values were compared between the three methods using a one-factor analysis of variance. Furthermore, the measurements of the anteverted and retroverted incisurae were compared for each fluoroscopic method. RESULTS: The mean interaxis angles between the TS were - 0.5 degrees, 6.3 degrees, and - 1.8 degrees for the IT, CC, and TL methods, respectively, with a significantly larger value for the CC method than for the IT and TL methods (P < .001). No significant difference was found in the interaxis angle in the anteverted (-0.1 degrees) and retroverted (-1.0 degrees) incisurae when using the IT method (P = .15). The angles in the retroverted incisurae were larger than those of the anteverted incisurae for the CC and TL methods. CONCLUSION: The fluoroscopic IT method accurately estimated the TS axis. The interaxis angles were consistent, regardless of the incisura anatomy. The fluoroscopic method can be used to clamp and fix the syndesmosis along the TS axis. LEVEL OF EVIDENCE: Ⅳ.

Investigating the Potential of Multilineage Differentiating Stress-Enduring Cells for Osteochondral Healing.

OBJECTIVE: Multilineage differentiating stress-enduring (Muse) cells, a pluripotent stem cell subset of mesenchymal stem cells (MSCs), have shown promise for various tissue repairs due to their stress tolerance and multipotent capabilities. We aimed to investigate the differentiation potential in vitro, the dynamics in vivo, and the reparative contribution of Muse cells to osteochondral lesions. DESIGN: Labeled MSCs were cultured and sorted into Muse and non-Muse (MSCs without Muse cells) groups. These cells were then formed into spheroids, and chondrogenic differentiation was assessed in vitro. Twenty-one immunocompromised mice were used as the in vivo models of osteochondral lesions. Live imaging, macroscopic evaluation, and histological and immunohistochemical analyses were conducted at the 4- and 8-week time points. RESULTS: Muse cell spheroids were formed, which were larger and stained more intensely with toluidine blue than non-Muse spheroids, indicating better chondrogenic differentiation. Live imaging confirmed luminescence in all 4-week model knees, but only in a few knees at 8 weeks, suggesting cell persistence. Macroscopically and histologically, no significant differences were observed between the Muse and non-Muse groups at 4 and 8 weeks; however, both groups showed better cartilage repair than that of the vehicle group at 8 weeks. No collagen type II generation was observed in the repaired tissues. CONCLUSION: The implantation of the spheroids of Muse and non-Muse cells resulted in better healing of osteochondral lesions than that of the controls, and Muse cells had a higher chondrogenic differentiation potential in vitro than non-Muse cells.

Number of intra-operative cyclic knee motion required to achieve stable graft tension in anterior cruciate ligament reconstruction; a prospective clinical study.

BACKGROUND: Applying pretension by cyclic knee motion immediately before graft fixation in anterior cruciate ligament (ACL) reconstruction surgery decreases graft elongation during the postoperative course. However, the expected change in graft tension caused by cyclic knee motion remains unclear. We measured graft tension changes caused by cyclic knee motion during double-bundle ACL reconstruction. METHODS: We included 39 patients undergoing primary anatomical double-bundle ACL reconstruction with autologous hamstrings as graft sources, at multiple centers between February 2021 and August 2022. After securing the anteromedial (AM) and posterolateral (PL) bundle grafts to the femoral cortex, they were initially tensioned to 40 N per bundle. After 10 cycles of knee extension and flexion motion, ranging from 0 to 90-110°, tension was re-measured and re-tensioned to 40 N if the graft tension had decreased. This was repeated thrice for 10 cycles on each graft. Every 10 cycles, we recorded graft tension changes (ΔGT) and compared the mean ΔGT in the AM and PL bundles. Furthermore, we assessed relationships between total ΔGT in each bundle, age, sex, and graft diameter. RESULTS: Twenty-five women and 14 men with a mean age of 27.4 ± 12.4 years were included. The mean ΔGT in AM and PL bundles after every 10 cycles were 6.6 ± 3.7 N, 3.0 ± 2.3 N, 1.4 ± 1.5 N, and 9.9 ± 3.8 N, 4.9 ± 2.6 N, and 2.5 ± 1.9 N, respectively. There were significant differences in ΔGT in both bundles after every 10 cycles (p < 0.01). ΔGT in the AM bundle was significantly lower than in the PM bundle at the same number of cycles (p < 0.01). No correlation was observed between ΔGT in either bundle and age, sex, or graft diameter. CONCLUSIONS: The initially applied graft tension decreased by intra-operative cyclic knee movement, and the changes in graft tension decreased after retention and repeated cycles. Three sets of 10 cycles knee motion may avoid initial tension loss of the hamstring autograft in the early phase after double-bundle ACL reconstruction.

Lateral meniscal injury without medial meniscal injury indicates the existence of the Segond fracture in ACL-deficient knees.

Background/Objective: The purpose of this study was to find factors indicating the occurrence of the Segond fracture, a specific type of anterolateral ligament injury. Methods: From January 2015 to December 2017, we retrospectively reviewed the medical records of patients diagnosed with acute anterior cruciate ligament (ACL) injury who underwent reconstruction within 90 days of injury. Diagnosis of the Segond fracture was determined either by magnetic resonance imaging or plain radiographs. Factors examined were: age at surgery, sex, body mass index (kg/m2), status of menisci, and activities led to ACL injury. After univariate screening, multivariate logistic regression analyses were performed. Patients were divided into four groups based on the presence of lateral meniscal (LM) and/or medial meniscal (MM) injuries and compared with respect to the occurrence of Segond fractures. Results: A total of 375 patients were included (163 males, 212 females), with mean age 25.8 years old. Among them, 22 of 375 (5.9 %) had a Segond fracture. We identified injured lateral menisci (adjusted odds ratio (aOR), 3.029; 95 % Confidence Interval (CI), 1.206-7.609; P = 0.018), intact medial menisci (aOR, 0.229; 95 % CI, 0.065-0.810; P = 0.022), and higher body mass index (aOR, 1.102; 95 % CI, 1.008-1.205; P = 0.034) as factors indicative of the occurrence of Segond fracture. LM injury without MM injury suggested the existence of a Segond fracture. Conclusion: LM injury without a MM injury indicated the occurrence of a Segond fracture. Higher body mass index also increased the risk for Segond fracture occurrence.

Variability in sonographic anterior drawer test measurements of the ankle: Experienced versus beginner examiners.

BACKGROUND: This study aimed to clarify the variability in the measurements of stress sonography of the ankle and determine the effects of examiner experience on the measurements. METHODS: Twenty examiners (10 experienced and 10 beginners) were included in the study. Each examiner performed stress ultrasonography on a patient with a chronic anterior talofibular ligament injury and a patient with an intact ligament using the reverse anterior drawer method. Changes in ligament length before versus after stress were determined. The same 20 examiners performed ultrasonography on two other patients with an injured or intact ATFL using the anterior drawer method. The length change values and variance were compared between the groups using t-tests and F-tests. RESULTS: Using the reverse anterior drawer method, the change in the anterior talofibular ligament length was 3.3 mm (range, 2.2-4.8 mm) in the experienced group and 2.7 mm (0.0-4.1 mm) in the beginner group for the ligament injured patient. The length changes for the patient with intact anterior talofibular ligament were 0.5 mm (0.1-0.9 mm) and 0.4 mm (-0.1-1.5 mm) in the experienced and beginner groups, respectively. There were no significant intergroup differences in measurement amount (P = 0.37) or variance (P = 0.72). Similarly, using the anterior drawer method, no significant differences between the groups were found in measurement amount or variance. CONCLUSION: The quantitative evaluation of stress sonography of the ankle was variable regardless of examiner experience or stress method, particularly in patients with an anterior talofibular ligament injury. The amount of variability appeared to be unacceptably large for clinical application. Our study results highlight the need for technical standardization.

Exocrine Pancreatic Insufficiency Possibly Related to Atypical Chronic Graft-versus-Host Disease.

We report the case of a 66-year-old woman who presented with diarrhea and weight loss approximately 14 months after unrelated allogeneic bone marrow transplantation for acute myeloid leukemia. Her early post-transplant course was notable for mild acute skin graft-versus-host disease (GVHD) and biopsy-proven upper gastrointestinal (GI) acute GVHD, both of which resolved with treatment. She then developed weight loss and diarrhea treated with prednisolone for what was thought to be GI late acute GVHD. However, her diarrhea and weight loss persisted. Colonoscopy showed a grossly intact mucosa, and stool studies only confirmed steatorrhea. However, an atrophic pancreas was found on an abdominal computed tomography (CT) scan. Exocrine pancreatic enzymes, such as lipase and pancreatic amylase, were markedly decreased, yet pancreatic endocrine function remained intact. The patient's diarrhea and weight loss improved upon treatment with pancrelipase. Therefore, we suggest that her exocrine pancreatic insufficiency was likely partly caused by atypical chronic GVHD.

Internet search analysis on the treatment of rheumatoid arthritis: What do people ask and read online?

OBJECTIVES: This study aimed to characterize the content of frequently asked questions about the treatment of rheumatoid arthritis (RA) on the internet in Japan and to evaluate the quality of websites related to the questions. METHODS: We searched terms on the treatment of RA on Google and extracted frequently asked questions generated by the Google "people also ask" function. The website that answered each question was also obtained. We categorized the questions based on the content. The quality of the websites was evaluated using the brief DISCERN, Journal of American Medical Association benchmark criteria, and Clear Communication Index. RESULTS: Our search yielded 83 questions and the corresponding websites. The most frequently asked questions were regarding the timeline of treatment (n = 17, 23%) and those on the timeline of the clinical course (n = 13, 16%). The median score of brief DISCERN was 11 points, with only 7 (8%) websites having sufficient quality. Websites having sufficient quality based on the Journal of American Medical Association benchmark criteria and Clear Communication Index were absent. CONCLUSIONS: The questions were most frequently related to the timeline of treatment and clinical course. Physicians should provide such information to patients with RA in the counseling and education materials.

Differential Associations of Sports Participation With Self-Rated Health and Depressive Symptoms Among Japanese Adolescents.

INTRODUCTION: We aimed to evaluate the associations of sports participation with self-rated health and depressive symptoms in a nationally representative sample of Japanese adolescents. METHODS: A questionnaire survey was conducted with 1,658 adolescents aged between 12 and 21 years. Sports participation levels were divided into high-frequency, moderate-frequency, low-frequency, and no-participation groups. Self-rated health was evaluated using a four-grade scale. Depressive symptoms were assessed using the Japanese version of the Patient Health Questionnaire-8. Other lifestyle behaviors were also surveyed. The associations of sports participation with self-rated health and depressive symptoms were examined using multiple logistic regression analysis. RESULTS: The participants in the high- (odds ratio (OR), 0.45) and moderate-frequency (OR, 0.46) groups were less likely to self-report poor health than those in the non-participation group. By contrast, a U-shaped association was found between sports participation and depression, in which the participants in the moderate-frequency group (OR, 0.52) were less likely to have depressive symptoms. The OR for the high- (0.89) and low-frequency (0.91) groups were not significant. Furthermore, eating regular breakfasts, six or more days/week, and having shorter screen times of less than two hours/day were negatively associated with poor self-reported health and depressive symptoms. CONCLUSION: Moderate- to high-frequency sports activities are associated with a reduced risk of poor self-rated health among Japanese adolescents. However, only moderate-frequency activities were associated with a reduced risk of depression. Participation in optimal sports activities may effectively lower the risk of poor health in adolescents.

Validity of the Center-Center Method for the Syndesmotic Fixation Axis Compared to the Transsyndesmotic Axis.

BACKGROUND: Placement of clamp forceps along the transsyndesmotic (TS) axis reduces the risk of iatrogenic syndesmotic malreduction during ankle fracture surgery with tibiofibular diastasis. This study aimed to measure the difference between the TS axis and the axis determined by an intraoperative fluoroscopic technique using the center-center (CC) method. We also compared the values obtained when the CC method was performed at different heights from the tibial plafond. METHODS: We evaluated the computed tomography scans of 150 patients with normal syndesmosis. The CC method was simulated using digitally reconstructed radiographs. The TS and CC axes were projected onto an axial computed tomographic image linked to digitally reconstructed radiography. The angle between the two axes (interaxis angle) and the distance between the intersection of these axes and the medial tibial cortex (interaxis distance) were measured. The procedures were performed 0, 10, and 20 mm proximal to the tibial plafond, and the measurements were compared among the different heights using a 1-way repeated-measures analysis of variance. RESULTS: The TS axis was found to be externally rotated to the CC axis, with an interaxis angle of 8.5 degrees (SD, 6.8 degrees). The interaxis angle increased from 1.9 degrees at a height of 0 mm to a greater angle at higher heights (P < .001). The overall interaxis distance was 7.7 (SD, 6.3) mm, increasing from 2.0 mm at a height of 0 mm to a greater distance at higher heights (P < .001). CONCLUSION: The TS axis was externally rotated relative to the CC axis, and the difference between the 2 axes was greater when the CC method was performed on the higher heights from the tibial plafond. To clamp the syndesmosis along the TS axis, the CC method should be applied close to the ankle joint. LEVEL OF EVIDENCE: Level IV, case series.

Readability and quality of online patient resources regarding knee osteoarthritis and lumbar spinal stenosis in Japan.

BACKGROUND: This study aimed to quantify the readability and quality of online patient resources on knee osteoarthritis and lumbar spinal stenosis in Japan. METHODS: Three search engines (Google, Yahoo, and Bing) were searched for the terms knee osteoarthritis and lumbar spinal stenosis. The first 30 websites of each search were screened. Duplicate websites and those unrelated to the searched diseases were excluded. The remaining 125 websites (62 on knee osteoarthritis, 63 on lumbar spinal stenosis) were analyzed. The text readability was assessed using two web-based programs (Obi-3 and Readability Research Lab) and lexical density. Website quality was evaluated using the DISCERN score, Clear Communication Index, and Journal of American Medical Association benchmark criteria. RESULTS: Readability scores were high, indicating that the texts were difficult to understand. Only 24 (19%) and six (5%) websites were classified as average difficulty readability according to Obi-3 and Readability Research Lab, respectively. The overall quality of information was low, with only four (3%) being rated as having sufficient quality based on the Clear Communication Index and Journal of American Medical Association benchmark criteria. None of the websites satisfied the DISCERN quality criteria. CONCLUSIONS: Patient information on Japanese websites regarding knee osteoarthritis and lumbar spinal stenosis were difficult to understand. Moreover, the quality of the websites was insufficient. Orthopaedic surgeons should contribute to the creation of high-quality easy-to-read websites to facilitate patient-physician communication.

Referential values for lower limb flexibility in healthy children and adolescents in Japan: A five-year cross-sectional study.

BACKGROUND: Lower limb flexibility (LLF) is an essential motor function. However, assessing LLF during adolescence is difficult because of the influence of marked physical changes. We, therefore, assessed LLF and investigated the relationship between LLF and sex and age in healthy children and adolescents. METHODS: We conducted a five-year cross-sectional study with students aged 8-14 years at a single school in Japan. We evaluated the heel-buttock distance (HBD), straight leg raising angle (SLRA), and dorsiflexion angle of the ankle joint (DFA) at the beginning of each year. We conducted a comparative analysis on the performance of the HBD, SLRA, and DFA techniques, stratified by both sex and age. The statistical significance of observed differences was assessed through the application of Mann-Whitney U and Kruskal-Wallis tests. Furthermore, we analyzed the effects of sex, age, height, and weight on LLF using a multivariable linear regression model. RESULTS: Of the 4221 initial study participants, 3370 were analyzed. Mean HBD, SLRA, and DFA values were 1.6 cm, 77.0°, and 15.7°, respectively. Girls showed significantly higher HBD and lower SLRA and DFA values than boys and 14-year-olds (p < 0.01). Median HBD value for girls was 0 cm, whereas for boys, it exceeded 0 cm after age 13. The median SLRA value for girls was 80-85°, while for boys, it was 70-75°. The median DFA value for girls was 15-19°, and for boys, it was 12-15°. A multivariable linear regression model indicated that boys had significantly greater tightness than girls (p < 0.01). CONCLUSIONS: The reference values of HBD, SLRA, and DFA differed according to age and sex. Furthermore, we showed that sex differences were significantly associated with LLF. Data in this study provide the reference value for assessing LLF in children and adolescents.

Classification From Positive and Biased Negative Data With Skewed Labeled Posterior Probability.

The binary classification problem has a situation where only biased data are observed in one of the classes. In this letter, we propose a new method to approach the positive and biased negative (PbN) classification problem, which is a weakly supervised learning method to learn a binary classifier from positive data and negative data with biased observations. We incorporate a method to correct the negative influence due to a skewed confidence, which is represented by the posterior probability that the observed data are positive. This reduces the distortion of the posterior probability that the data are labeled, which is necessary for the empirical risk minimization of the PbN classification problem. We verified the effectiveness of the proposed method by synthetic and benchmark data experiments.

Peroneus brevis tear caused by an impingement between hypertrophied peroneal tubercle and lateral malleolus.

We report a 15-year-old female patient who sustained peroneus brevis injury caused by an impingement between the hypertrophied peroneal tubercle and lateral malleolus. The patient had pain for 3 years in the lateral side of her left ankle with unsuccessful conservative treatment. The oblique sagittal images of 3-dimensional magnetic resonance imaging and ultrasonography were useful in depicting the peroneus brevis injury and identifying the location of impingement between the hypertrophied peroneal tubercle and the tip of the lateral malleolus. The flatfoot deformity of the patient further aggravated the impingement. The patient was treated surgically, with excision of the enlarged tubercle and tendon repair. The ankle pain resolved 12 months postoperatively. Although rare, clinicians should recognize this condition as the cause of lateral ankle pain.

Foot morphology and correlation with lower extremity pain in Japanese children: A cross-sectional study of the foot posture Index-6.

BACKGROUND: Abnormal foot morphology in children and adolescents is a possible risk factor for lower extremity pain. Foot posture index-6 (FPI-6) is a valid and reliable tool to assess foot morphology. However, the normative data on the age distribution for FPI-6 in Asian children and adolescents are still minimal. Further, the correlation of FPI-6 with lower extremity pain is poorly understood. We aimed to investigate the normative distribution for FPI-6 and the relationship between FPI-6 scores and knee and heel pain in Japanese children. METHODS: We included 2569 Japanese children, aged 9-15 years, at a single school from 2016 to 2018. We summarized the age distribution of children and their mean bilateral FPI-6 scores. Additionally, we assessed the tenderness at the apophysis or tendon insertions at the knee and heel. We performed a cross-sectional analysis to investigate the correlations between FPI-6 scores and sex, age, and knee and heel pain for the data obtained each year. RESULTS: The mean FPI-6 score was 3.1 ± 2.4, 3.4 ± 2.0, and 3.2 ± 1.9 for the left foot and 3.0 ± 2.4, 3.2 ± 1.9, and 3.1 ± 1.9 for the right foot in 2016, 2017, and 2018, respectively. Boys tended to have higher scores than girls, and the FPI-6 score of the left foot was significantly higher than that of the right foot (p < 0.05). There was no correlation between FPI-6 scores and knee and heel pain. CONCLUSION: Children and adolescents between 9 and 15 years of age have neutral to slightly pronated foot morphology and an average FPI-6 score of 3.0-3.4. In addition, there was no relationship between foot morphology and knee and heel pain. This normative distribution for FPI-6 in Japanese children could serve as a reference value for future research and clinical evaluation.

The influence of COVID-19 pandemic on the incidence of knee pain and physical activity level in children and adolescents in Japan: A prospective observation study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has had a profound impact on children's lifestyles. Some studies have reported psychological changes in children after the pandemic, but information on musculoskeletal problems is scarce. This study aimed to investigate the incidence of knee pain and changes in physical activity after the spread of COVID-19 among elementary and junior high school students in Japan. METHODS: Knee pain and amount of physical activity were recorded on a monthly basis between August 2019 and February 2021 in children aged 8-14 years using a self-administered questionnaire. The amount of physical activity was scored using the Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS). The period until February 2020 was defined as "Before pandemic," and the period from March 2020 was defined as "After pandemic." The incidences of knee pain and HSS Pedi-FABS scores before and after the COVID-19 pandemic were compared. Additionally, we compared the prevalence of knee pain and HSS Pedi-FABS scores according to sex and age. RESULTS: We enrolled 886 and 881 participants before and after the pandemic, respectively. The prevalence of knee pain among the participants before and after the pandemic was 6.7% and 7.9%, respectively (p = 0.032). The mean HSS Pedi-FABS scores before and after the pandemic were 14.8 and 14.5, respectively (p = 0.005). Participants aged 14 years had a significantly lower incidence of knee pain (p = 0.013) and significantly higher HSS Pedi-FABS scores (p < 0.001) after the spread of COVID-19. CONCLUSIONS: In elementary and junior high school students, increase in the incidence of knee pain and decrease in the amount of physical activity after the spread of COVID-19 were observed.

Nuclear receptor subfamily 1 group D member 1 in the pathology of obesity-induced osteoarthritis progression.

Mechanical overload and chemical factors are both related to obesity-induced progression of knee osteoarthritis. The circadian rhythm is related to the development of metabolic syndrome and the progression of osteoarthritis, and the core clock genes nuclear receptor subfamily 1 group D member 1 (NR1D1) and brain and muscle arnt-like protein 1 (BMAL1) are dysregulated in cartilage from patients with osteoarthritis. Here, we focused on NR1D1 and investigated osteoarthritis-related changes and gene expression in a mouse model of diet-induced obesity. A high-fat diet was provided to C57BL6/J mice, and changes in body weight, blood lipids, and gene expression were investigated. Destabilization of the medial meniscus or sham surgery was performed on mice fed a high-fat diet or normal diet, and histological osteoarthritis-related changes and NR1D1 expression were investigated. The effects of the NR1D1 agonist SR9009 were also assessed. Mice fed a high-fat diet developed significant obesity and dyslipidemia. Nr1d1 and Bmal1 gene expression levels decreased in the liver and knee joints. Moreover, increased osteoarthritis progression and decreased NR1D1 protein expression were observed in high-fat diet-fed mice after surgical osteoarthritis induction. SR9009 decreased the progression of obesity, dyslipidemia, and osteoarthritis. Overall, obesity and dyslipidemia induced by the high-fat diet led to osteoarthritis progression and decreased NR1D1 expression. Thus, NR1D1 may play an important role in obesity-induced osteoarthritis.

Risk factors for the occurrence and protraction of patellar and patellar tendon pain in children and adolescents: a prospective cohort study of 3 years.

BACKGROUND: Patellar and patellar tendon pain is a common limitation to children's participation in social and physical activities. Some factors have been implicated in the occurrence and protraction of knee pain, but the causal relationship is unknown. The purpose of this study was to investigate whether participants' physical characteristics and activity level are risk factors for the occurrence and protraction of patellar and patellar tendon pain in children and adolescents. METHODS: A three-year prospective cohort study was conducted with healthy students who were aged 8-14 years old, in Japan. Height, weight, heel-buttock distance, straight leg raising angle, and dorsiflexion angle of the ankle joint were collected as individual physical factors at the beginning of each year. The presence of self-reported patellar and patellar tendon pain and the Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS) was collected every month. Protraction was defined as either (1) pain lasting for more than three continuous months or (2) recurrent pain after more than three months of complete recovery. Participants who did not have any pain at the beginning of the observation period were included in the analysis. We analyzed the odds ratio (OR) of pain occurrence within a year of registration and protraction throughout the study period for all physical factors and HSS Pedi-FABS. RESULTS: We included 1133 participants in the analysis and 252 participants developed knee pain within a year. 34.8% of participants with pain experienced protraction during the follow-up period. A high HSS Pedi-FABS significantly predicted knee pain occurrence (OR 1.03, 95% confidence interval [CI] 1.01-1.05) and protraction (OR 1.03, 95% CI 1.00-1.05). In addition, younger children and girls were at a significantly higher risk of patellar and patellar tendon pain protraction (age, OR 0.81, 95% CI, 0.73-0.90; sex, OR 1.69, 95% CI, 1.09-2.64). Other physical factors did not significantly predict the occurrence or protraction of knee pain. CONCLUSIONS: This study showed that a greater physical activity level was a risk factor for the occurrence and protraction of patellar and patellar tendon pain in childhood. In addition, younger age and female sex predicted higher risk of protraction of pain.

Comparison of joint awareness after medial unicompartmental knee arthroplasty and high tibial osteotomy: a retrospective multicenter study.

INTRODUCTION: Unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO) are established treatments for medial compartment osteoarthritis (OA) or osteonecrosis (ON) of the knee joint, and the predominance of either procedure is inconclusive. We compared the awareness of the knee after UKA and HTO using the Forgotten joint score-12 (FJS). MATERIALS AND METHODS: This was a retrospective, multicenter study. Ninety-six knees of 90 patients who received UKA or HTO and were followed-up for at least 1 year were analyzed. Postoperative FJS was compared between the two groups and evaluated for the effect of patient-related factors and clinical outcomes. Multiple linear regression analysis was performed to predict FJS. RESULTS: There was no significant difference in the FJS between the UKA and HTO groups (p = 0.24). FJS did not correlate with any of the patient-related factors. There was a correlation between the FJS and each item of the Knee Injury and Osteoarthritis Outcome Scores (KOOS) and Lysholm Knee Scoring Scale (LKS). In multiple linear regression analysis, lower BMI, the diagnosis of OA Kellgren-Lawrence (KL) grade ≥ 3, and ON were significant predictors of better FJS. In both groups, FJS was correlated with each item of the KOOS and LKS. Internal consistency in terms of Cronbach's alpha was excellent. CONCLUSIONS: There was no significant difference in FJS between patients who underwent UKA and HTO. Lower BMI, the diagnosis of OA KL grade ≥ 3, and ON were significant predictors of better FJS.