Trochleoplasty in major trochlear dysplasia: current concepts.

Philippe Beaufils,Sven Scheffler,Mathieu Thaunat,Mike Carmont,Nicolas Pujol,Roberto Rossi

doi:10.1186/1758-2555-4-7

Abstract

Trochleoplasty is the theoretical solution to persistent symptoms (pain and/or instability) related to trochlear dysplasia where there is not only a trochlear flatness but also a trochlear prominence. The threshold of prominence indicating surgical intervention has as yet not been determined. A bump of 5 mm is generally accepted as the inferior limit. Given the interventional nature of this demanding procedure, it should be proposed in selected cases after considerable discussion with the patient. Trochleoplasty is indicated as a primary procedure for major trochlear dysplasia with a prominence > 5 mm. Stabilization is obtained in most of the cases with the risk of residual mild anterior knee pain. It is also indicated as a salvage procedure when a previous surgery failed. Despite the reputation of the procedure, the published results are encouraging in terms of prevention of re-dislocation, satisfaction index, and radiological outcomes. Post-operative stiffness is the main complication, which may require manipulation under anaesthesia or arthroscopic arthrolysis. There are few other complications reported and to date secondary necrosis of the trochlea has not been reported. Technically speaking, the deepening trochleoplasty is a difficult procedure without reliable landmarks. We propose a recession wedge trochleoplasty which is an easier procedure. It is never undertaken as an isolated procedure, but always in conjunction with other realignment procedures of the extensor apparatus according to the "a la carte" surgery concept.

Highlights

The importance of a dysplastic trochlea as a component of patellar instability has been recognized for many years
Trochleoplasty can be proposed as a primary procedure for primary trochlea dysplasia or as a salvage procedure [13] in case of failure after previous patellar alignment surgery, principally Anterior Tibial Tubercle Transfer (ATTT)
Recession trochleoplasty has several advantages: diminishing the trochlear bump improves patellar tracking, reduces lateral subluxation and decreases patellofemoral constraint by increasing the angle between the quadriceps muscle force and the patellar tendon force. This has become our preferred technique and we have reported the outcome of 24 cases of recession trochleoplasty performed between 2004 and 2009 [14]

Summary

Introduction

The importance of a dysplastic trochlea as a component of patellar instability (especially recurrent dislocation or habitual dislocation) has been recognized for many years. In our experience the restoration of the trochlea groove by trochleoplasty prevents future patellar dislocation and is effective in reducing anterior knee pain. Elevation of the lateral trochlear facet was first described by Albee [3] in 1915, followed by deepening trochleoplasty [2,4,5,6,7,8,9,10,11,12] which tries to create a new sulcus by removing subchondral bone.

Results

Conclusion