Audit-induced change reduces complications of the Ganz trochanteric flip approach

INTRODUCTION

The Ganz trochanteric flip approach aims to avoid the potential risk of avascular necrosis in hip conserving surgery and may reduce the risk of femoral neck fractures, neck thinning and femoral head implant migration in hip resurfacing. Our initial audit revealed the complications of non-union and trochanteric screw irritation to be associated with this approach. We, therefore, modified our selection criteria and re-audited our results.

SUBJECTS AND METHODS

The initial audit (IA) ran between January 2003 and November 2007 after which an age limit of 50 years was recommended. The re-audit (RA) ran between November 2007 and December 2008 where one of the senior authors stopped using the approach in the over 50 year age group whilst the other senior author continued on selected patients over 50 years.

RESULTS

There were 545 hips in the IA and 152 hips in the RA group. The incidence of non-union decreased in the RA after the change of selection criteria (6.2% [IA] vs 1.3% [RA]). In both audit groups, the incidence of non-union increased with age, and in the RA no non-unions were observed under the age of 50 years. The incidence of screw irritation and the necessity for removal remained relatively unchanged (20.7% [IA] vs 28.3% [RA]) with a combined incidence of 22.4%.

CONCLUSIONS

The trochanteric flip approach to the hip can be used safely with an acceptable complication rate in young adult impingement and resurfacing surgery. Caution must, however, be exercised in patients over 50 years of age as they have a higher incidence of trochanteric non-union. In addition, all patients should be consented for the possibility of screw removal as a second procedure.