Recession wedge trochleoplasty as an additional procedure in the surgical treatment of patellar instability with major trochlear dysplasia: early results.

INTRODUCTION

The importance of a dysplastic trochlea as a component of patellar instability has long been recognized. An original trochleoplasty technique consisting in retro-trochlear recession wedge osteotomy was described by Goutallier et al. The aim is not to fashion a groove but to reduce the bump without modifying patellofemoral congruence.

PATIENTS AND METHODS

This retrospective study reports the operative technique and short-term outcomes of a consecutive case series of 17 patients (19 knees) who underwent recession wedge trochleoplasty for patellofemoral instability associated with severe trochlear dysplasia. Other contributing factors of patellar instability were also corrected as part of the surgical procedure: tibial tuberosity transfer (n=18), MPFL reconstruction (n=8).

RESULTS

Minimum follow-up was 12 months (mean, 34 months; range, 12 to 71 months). The trochlear prominence was reduced from a mean 4.8mm (range, 0 to 8mm) to -0.8mm (range, -8 to 6mm). Patellar tilt was reduced from a mean 14° (range, 6° to 26°) to 6° (range, -1° to 24°). Two cases showed recurrent patellofemoral instability. Mean Kujala, KOOS and IKDC score were respectively 80 (± 17), 70 (± 18) and 67 (± 17) at last follow-up. Three patients required further operations, apart from removal of metal screws: arthroscopic arthrolysis for stiffness (n=1), revision for tibial tuberosity non-union (n=1), and supratrochlear exostosectomy (n=1).

DISCUSSION

Recession wedge trochleoplasty is a feasible additional procedure addressing bony trochlear abnormality in the surgical treatment of patellar instability. Our attitude is to perform it never in isolation but associated to realignment of the extensor apparatus according to the à la carte surgery concept. It seems to be effective in preventing future patellar dislocation and reducing anterior knee pain in case of painful patellofemoral instability with a major dysplastic trochlea, or in revision cases when other realignment procedures have failed.