The relationship of the MPFL femoral attachment footprint to the femoral physis in the skeletally immature patient is not well understood, and access to pediatric cadaveric tissue is very limited. This small series demonstrates that there is considerable variation in the relationship between the MPFL and distal femoral physis. This anatomic information may guide MPFL reconstruction technique in young patients and reduce the risk of iatrogenic physeal arrest on the femur.

Background:The frequency of osteochondritis dissecans (OCD), a disorder of the subchondral bone and articular cartilage, is not well described.Purpose:To assess the frequency of pediatric OCD lesions that progress to surgery based on sex, joint involvement, and age.Study Design:Descriptive epidemiology study.Methods:A retrospective chart review (2007-2011) was performed on OCD. Inclusion criteria included OCD of any joint and patients aged 2 to 19 years. Exclusion criteria included traumatic osteochondral fractures or coexistence of non-OCD intra-articular lesions. Differences in progression toward surgery were compared between age groups, sex, and joint location. Logistical regression analysis was performed by sex, age, and ethnicity.Results:Overall, 317 patients with a total of 334 OCD lesions were found. The majority of lesions (61.7%) were in the knee, with ankle, elbow, shoulder, and foot lesions representing 25.4%, 12.0%, 0.6%, and 0.3% of all lesions, respectively. The majority of joints needing surgery were in the knee (58.5%), with ankle and elbow lesions representing 22.9% and 18.6% of surgeries performed, respectively. The percentage of all OCD lesions progressing to surgery was 35.3%; surgical progression for knee, ankle, and elbow joints was 33.5%, 31.8%, and 55.0%, respectively. Logistic regression analysis found no statistically significant different risk of progressing to surgery for OCD of the knee, elbow, and ankle between sexes. Patients aged 12 to 19 years had a 7.4-times greater risk of progression to surgery for knee OCD lesions than 6- to 11-year-olds. Patients aged 12 to 19 years were 8.2 times more likely to progress to surgery for all OCD lesions than patients aged 6 to 11 years. Progression to surgery of ankle OCD did not significantly differ based on location. Three of 4 trochlear lesions progressed to surgery, along with 1 of 1 tibial, 1 of 3 patellar, 40.3% of lateral femoral condylar, and 28.2% of medial femoral condylar lesions.Conclusion:In this large cohort study of pediatric OCD patients, 35% progressed to surgery. Progression to surgery did not differ significantly between sexes with OCD of any joint. Progression to surgery for OCD of the knee, elbow, and ankle strongly correlated with patient age at the time of diagnosis.Clinical Relevance:The knowledge of likelihood of progression to surgery of OCD by location, sex, and age is useful in counseling patients and in planning treatment. This study confirms a worse prognosis in the nonoperative treatment of older patients with OCD.

Background: The clinical and radiographic features of iatrogenic hip instability following hip arthroscopy have been described. However, the prevalence of presenting symptoms and associated imaging findings in patients with hip instability has not been reported. Purpose: To detail the prevalence of clinical and magnetic resonance arthrogram (MRA) findings in a cohort of patients with isolated hip instability and to determine midterm patient-reported outcomes in this patient population. Study Design: Case series; Level of evidence, 4. Methods: We retrospectively reviewed patients from 2014 to 2016 who underwent an isolated capsular repair in the revision hip arthroscopy setting. Patients were excluded if they underwent any concomitant procedures, such as labral repair, reconstruction, femoral osteoplasty, or any other related procedure. Several clinical data points were reviewed, including painful activities, mechanical symptoms, subjective instability, Beighton scores, axial distraction testing (pain, toggle, and apprehension), and distractibility under anesthesia. Patient-reported outcomes—including modified Harris Hip Score, Hip Outcome Score–Sports Subscale, Patient-Reported Outcome Measurement Information System (PROMIS) Physical Function Computer Adaptive Test, and a return patient hip questionnaire—were collected pre- and postoperatively. Pre-revision radiographs were obtained, and lateral center-edge angle and alpha angle were measured on anteroposterior and frog-leg lateral views, respectively. Pre-revision MRAs were reviewed and evaluated for capsular changes. Capsular changes were defined as follows: 0, normal; 1, capsular redundancy; 2, focal capsular rent; and 3, gross extravasation of fluid from the capsule. Results: A total of 31 patients met inclusion criteria (5 male, 26 female; 14 right and 17 left hips). The mean age of patients was 36 years (range, 20-58 years). Overall, 27 (87%) reported hip pain with activities of daily living, and 31 (100%) experienced pain with sports or exercise. In addition, 24 (77%) had at least 1 positive finding on axial distraction testing. All patients had evidence of capsular changes on review of pre-revision MRAs. Out of 31 patients, 23 (74%) were available for follow-up at a minimum of 3.3 years and a mean ± SD of 4.6 ± 0.8 years. On average, modified Harris Hip Score improved by 20.3, Hip Outcome Score–Sports Subscale by 25.1, and PROMIS Physical Function Computer Adaptive Test by 6.4. Additionally, 20 (87%) patients reported improved or much improved physical ability, and 18 (78%) reported improved or much improved pain. Conclusion: The current study suggests that patients with hip instability demonstrate high rates of pain with activities of daily living and exercise, positive findings on axial distraction testing, and evidence of capsular changes on magnetic resonance imaging. Furthermore, these patients improve with revision surgery for capsular repair at midterm follow-up.

This information shows anatomic variation of the MPFL origin with age, with older specimens having a footprint that was more proximal and anterior than younger specimens. Customization of the surgical technique might be considered based on patient age.

Background:Osteochondritis dissecans (OCD) of the elbow is a disorder of subchondral bone and articular cartilage, of which the incidence among children is not clearly known.Purpose:To assess the demographics and epidemiology of OCD of the elbow among children.Study Design:Cross-sectional study; Level of evidence, 3.Methods:A retrospective chart review of an integrated health system for the years 2007 through 2011 was performed for patients with elbow OCD aged 2 to 19 years. Lesion location, laterality, and all patient demographics were recorded. OCD incidence was determined for the group as a whole as well as by sex and age group (2-5, 6-11, 12-19 years). Patient differences based on age, sex, and ethnicity were analyzed, and multivariable logistic regression models were used to assess the risk of elbow OCD by group.Results:A total of 37 patients with 40 OCD lesions fit the inclusion criteria. No lesion was found among 2- to 5-year-olds. A majority of lesions (n = 39, 97.5%) were in the capitellum, and 1 (2.5%) was in the trochlea. Twenty-five patients (67.6%) had right-sided lesions; 9 (24.3%), left-sided; and 3 (8.1%), bilateral. The incidence of elbow OCD for patients aged 6 to 19 years was 2.2 per 100,000 overall and 3.8 and 0.6 per 100,000 for males and females, respectively. The majority of OCD cases were seen in those aged 12 to 19 years, with an incidence of 3.4 per 100,000 versus 0.38 among 6- to 11-year-olds. Multivariable logistic regression analysis revealed a 21.7-times increased odds ratio of elbow OCD among patients aged 12 to 19 years versus 6 to 11 years, and males had a 6.8-times greater odds ratio of elbow OCD than females (P < .0001 for both). Based on race and ethnicity, non-Hispanic whites had the highest incidence of elbow OCD as compared with all other ethnic groups.Conclusion:In this population-based cohort study of pediatric elbow OCD, males had almost 7 times the risk of elbow OCD as compared with females, and 12- to 19-year-olds had nearly 22 times the risk of elbow OCD versus 6- to 11-year-olds. In keeping with many prior studies, the majority of patients had right-sided lesions.