Abductor mechanism tears in primary total hip arthroplasty

Introduction

Tears of the abductor mechanism of the hip are well recognized, but poorly understood. Little is known of the effect of demographics and pathology on prevalence of abductor mechanism tears or the impact on clinical outcome.

Methods

This prospective study analysed the effect of age, gender, medical co-morbidity and social deprivation on prevalence of abductor mechanism tears of the hip in 835 consecutive patients undergoing total hip arthroplasty (THA) between 2003 and 2011. Effect on clinical outcome relating to presence of abductor mechanism tear was analysed in a subset at pre-op and at 1 year post-operation using the Oxford hip score (OHS).

Results

The prevalence of abductor mechanism tears was 25.4 % (n = 212). Female patients (p < 0.001), older patients (p = 0.001) and those of lower socioeconomic status (p < 0.001) were significantly more likely to have a pre-operative abductor mechanism tear. In older socially deprived females the predicted rate of tear is 70.9 %. The aetiology of the hip disease (p = 0.593) or presence of any specific co-morbidity (p = 0.085–0.929) had no significant effect on the prevalence of abductor mechanism tears. In patients with protrusion or dysplasia there was an increased prevalence of tears (p = 0.002). There was no significant difference in pre-operative (p = 0.775) or post-operative (p = 0.604) OHSs regardless of the tears when the tears were recognized and treated at the time of THA.

Conclusions

Tears are increasingly prevalent in women of advancing years and lower socioeconomic status which should be considered when planning operative approach in this demographic. When recognised and repaired there is no difference in the clinical outcome for those with abductor mechanism tears of the hip.