Percutaneous drilling for painful bipartite patella.

This study aimed to investigate the post-operative outcome of 14 patients 16 knees that were treated operatively with percutaneous drilling (D), screw fixation (S), and lateral retinacular release (LRR) for painful bipartite patella. All patients were male athletes, and were observed for a mean of 25.6 months. The average age of the patients was 14.9 years. The separated form of the bipartite fragment was classified as type II in 3 patients 4 knees, and type III in 12 patients 12 knees according to the Saupe classification. Growth plate was persistent in 11 patients 13 knees. D was performed in 8 patients 8 knees. D + S in 2 patients 3 knees, D + LRR in 3 patients 4 knees, and D + S + LRR in 1 patient 1 knee. Complete bony union of the separated fragment and the patella at final follow up was observed in 5 knees (31.3%), incomplete in 10 knees (61.5%), and non-union in 1 knee (6.3%). The bony union rate was not associated with surgical procedures and the presence of growth plate. Ten patients (71.4%) had returned to full sporting activities; especially all patients (4 patients 5 knees) who were treated with LRR had their pain relieved and returned to their original sporting activities. On the other hand, osteosynthesis such as D and S did not provide good clinical results. We suggest that lateral retinacular tension might influence patellofemoral pain of the bipartite patella and LRR is an effective procedure for painful bipartite patella without mal-alignment and patellar instability. [ABSTRACT FROM AUTHOR]