ABSTRACT
Purpose: To assess the postoperative timeline for the return to activities of daily living (ADLs) in pediatric patients after arthroscopic drilling of a stable osteochondritis dissecans (OCD) lesion of the knee and to determine the rate of and risk factors for complications after the procedure. Methods: In a retrospective chart review, data from all patients aged 18 years or younger who underwent arthroscopic drilling for a stable OCD lesion of either femoral condyle from May 2009 through July 2017 were collected. Demographic data, lesion characteristics, operative data, postoperative course, radiographic outcomes, and complications were recorded. Statistical analysis was performed to determine the risk factors for reoperations. Results: A total of 139 knees in 131 patients were evaluated, with a mean age of 12.7 years, of which 102 (73%) were male knees. The average follow-up period was 17.8 ± 13.2 months after surgery. All patients regained full extension and flexion within 5° of the contralateral knee at a mean of 12.9 ± 3.2 weeks postoperatively, with 95% having returned fully to ADLs by the 3-month postoperative visit. No cases of infection, stiffness, arthrofibrosis, or other procedure-related complications were recorded. A total of 133 knees (95.7%) showed healing on radiographs, whereas 6 knees (4.3%) underwent additional surgical procedures, all of which were performed for treatment failure related to nonhealing lesions (including loose body removal, chondroplasty, and repeated drilling). Lesion size was the only significant risk factor for reoperation (P = .02). Conclusions: Our findings suggest that arthroscopic drilling for stable, intact OCD lesions in the pediatric knee is a safe procedure with reliable outcomes and return to ADLs and a minimal risk of complications. Most patients return to their preoperative daily activity level with a full range of motion of the knee by 3 months after surgery. Complications, including reoperations, are related to the progression of the OCD lesion rather than to the surgical procedure. Each 1-cm2 increase in lesion size increases the likelihood of reoperation by 2.93 times. Level of Evidence: Level IV, therapeutic case series.
ABSTRACT
BACKGROUND: Identifying risk factors for recurrent patellar dislocation after a primary dislocation may help guide initial treatment. Magnetic resonance imaging (MRI) measurements relating the alignment of the extensor mechanism to trochlear morphology have been shown to distinguish patients with dislocations from controls, but their usefulness in predicting the risk of a second dislocation is not known. PURPOSE: To identify the association of novel MRI measures of patellar containment with recurrent instability in pediatric patients presenting with a first-time patellar dislocation. STUDY DESIGN: Cohort study (Prognosis); Level of evidence, 3. METHODS: The study was conducted at a tertiary care children's hospital (2005-2014) on patients (age, 8-19 years) with a first-time patellar dislocation. MRI measurements were made by 2 independent raters. Interobserver reliability was assessed for all measurements via an intraclass correlation coefficient (ICC). Only measurements with an ICC >0.8 were included. Univariable and multivariable logistic regression analyses were used to evaluate variables associated with recurrence. RESULTS: A total of 165 patients with a median age of 14 years and a slight (57.6%) female predominance was identified. The median follow-up length of the whole cohort was 12.2 months (interquartile range, 1.6-37.1 months). Subsequent instability was documented in 98 patients (59.4%). MRI measurements with excellent correlation (ICC > 0.8) were the tibial tubercle to trochlear groove distance (TT-TG), the tangential axial width of the patella, the tangential axial trochlear width, the axial width of the patellar tendon beyond the lateral trochlear ridge (LTR), and the tibial tubercle to LTR distance. In univariate analysis, all mentioned MRI measurements had significant association with recurrent instability. However, after both backward and forward stepwise regression analyses, the tibial tubercle to LTR distance was the only independent predictor of recurrent instability (P = .003 in both). Patients with a tibial tubercle to LTR distance value greater than -1 mm had a significantly higher rate of recurrent patellar dislocation (72%). CONCLUSION: Of numerous axial view MRI parameters, only the tibial tubercle to LTR distance demonstrated a statistically significant association with recurrent patellar instability upon multivariable logistic regression analysis during short-term follow-up of a pediatric population presenting with initial lateral patellar dislocation. Interobserver correlation of the tibial tubercle to LTR distance was good (ICC > 0.8) and similar to that of TT-TG.
