Knee osteochondral fractures in skeletally immature patients: French multicenter study

Femoral or patellar osteochondral fractures complicating patellar dislocation are more frequently observed in adolescents than in adults. These incidental lesions of vulnerable joint cartilage are often neglected in the initial phase, which is regrettable given their good capacity for healing after repositioning. The objective of this study was to investigate the characteristics and analyze the results of repositioning these fractures in skeletally immature patients.

This retrospective multicenter study grouped 14 patients and knees (seven females). The mean age at the time of the accident was 12.9 years (range, 11.2-14.9 years) for the girls and 14 years (range, 12.2-15 years) for the boys. These fractures involved the lateral condyle in nine cases and the patella in five cases. The injury mechanism was secondary to demonstrated patellar dislocation (n=9) or a direct impact (n=4). In nine cases out of 14, a leisure sports accident was the cause. The injury was treated a mean 5.2 days (range, 0-20 days) after the accident. All of the detached fragments were repositioned surgically with screw fixation (n=5), resorbable pins (n=5), or pull-out suture (n=4). Biological glue was added for six patients. Patellar stabilization was associated during the same procedure in two cases.

No postoperative complications were observed. The results at the mean follow-up of 30 months (range, 15-89 months) showed no revision for failure, with all of the fractures demonstrating union at the final examination. The mean IKDC 2000 subjective score was 88±6 (range, 79-98) out of 100 points. The subjective satisfaction level was very satisfied in two cases and satisfied in the 12 others. The final IKDC score was A for eight patients, B for five patients, and C for one patient. Three patients underwent secondary patellar stabilization surgery.

Better knowledge of this fracture and attentive reading of the radiographic images of a knee with hemarthrosis should result in more frequent diagnosis of this condition and adapted treatment. Unexplained hemarthrosis in a context of trochlear dysplasia should be considered to be associated with an OCF until proof of the contrary. A fragment released in a weightbearing zone should ideally be repositioned within 10 days but remains possible at 2 months. It regularly provides bone union and good results in children.