Purpose
To compare outcomes between mature and skeletally immature patients status-post open reduction and internal fixation (ORIF) of loose osteochondritis dissecans (OCD) fragments of the trochlea.
Methods
A retrospective chart review of grade IV OCD fixation surgeries performed by the senior author between 2010 and 2021 was completed identifying 134 patients. When screened for fixation type, grade, and location, 12 patients were identified who underwent ORIF of a loose trochlear defect. Patient demographics, history, imaging findings, surgical factors, fixation failure, and skeletal maturity were all collected and compared. Of the 12 patients identified, 10 (6 skeletally immature, 4 mature) were able to be contacted for telephone follow-up and KOOS and Marx scores. Comparative statistics were calculated using a Fischer’s exact and T-tests at p=0.05.
Results
12 patients (12 knees) were identified. 7 skeletally immature (SI) on radiographic findings and 5 skeletally mature (SM) knees were included for analysis with average follow-up of 77.5 months (range, 7.5 – 145). Long term success rates, based on reoperation of the index knee, showed no difference between skeletally immature and mature groups, 85.7% vs 80% (p=0.530), respectively. Average trochlear OCD lesion size was 2.97 cm2 (±1.05) in mature patients and 3.37 cm2 (±1.54) in skeletally immature patients. In patients available for telephone follow-up, there appears to be no significant difference in follow-up KOOS scores between skeletally immature and mature patients, 93.3±7.4 vs 80.5±18.8 (p=0.271), respectively. Breakdown of KOOS sub scores are depicted in Table 1 below. Further similarities can be appreciated in Marx activity scores between the same groups, 10.2±4.6 vs 8.0±7.5 (p=0.631).
Conclusion
ORIF of a loose trochlear OCD lesion yields favorable outcomes with low failure rate. Based on skeletal maturity, no difference in success rates or outcomes was appreciated in patients who had underwent ORIF of loose trochlear OCD fragments. Regardless of skeletal maturity, ORIF of loose trochlear OCD lesions may be an effective treatment for fragments amenable to fixation.