The Lyon's sulcus-deepening trochleoplasty in previous unsuccessful patellofemoral surgery

Trochleoplasty is a relatively rare operation with few published results and it remains a technically demanding procedure which requires careful patient selection. The ideal candidate for surgery remains to be elucidated, and some authors consider it as a good revision option in cases of previous unsuccessful operations for persisting patellar dislocation with underlying trochlear dysplasia. The purpose of this study is to record the results from the application of sulcus-deepening trochleoplasty in patients with trochlear dysplasia and previous unsuccessful surgery for patellar dislocation. Twenty-two patients (24 knees) were operated upon during the period 9/1993-9/2006; they had undergone surgery for patellofemoral instability and had persistent patellar dislocation, and were followed-up for a mean of 66 months (24-191). Trochleoplasty was performed in all patients using the same technique and rehabilitation protocol. Additional soft-tissue and bony operations were performed in every case. Of all cases, 29.1 % had type B and 70.9 % had type D trochlear dysplasia. After trochleoplasty, no patient had a patellar re-dislocation up to the last follow-up. Pain decreased in 72 % and the apprehension sign was negative in 75 % of the cases (p < 0.01). Sulcus angle decreased from 153A degrees A +/- 14A degrees to 141A degrees A +/- 10A degrees (p < 0.01), TT-TG distance decreased from 16 A +/- 6 mm to 12 A +/- 2 mm (p < 0.001), and patellar tilt decreased from 31A degrees A +/- 14A degrees to 11A degrees A +/- 8A degrees (p < 0.0001). Mean pre-operative Kujala score was 44 (25-73) and at the latest follow-up it increased to 81 (53-100), (p < 0.001). At the time of final follow-up, there was no case of patellofemoral arthritis. Trochlear dysplasia is a key factor in the treatment of recurrent patellar dislocation and its correction could be included in the surgical options. Sulcus-deepening trochleoplasty is an acceptable revision option for the surgical treatment of patients with persisting patellar dislocation and high-grade trochlear dysplasia.