Hip resurfacing using a modified lateral approach with limited splitting of the gluteus medius muscle results in significant impairment of hip abductor strength

Background: A lateral, transgluteal approach for hip resurfacing carries the risk of approach-related weakening of the hip abductors due to unsuccessful re-adaptation of the gluteal muscles to the greater trochanter or to injury to the inferior nerve branch of the superior gluteal nerve.

Objective: We investigated whether hip resurfacing using a soft tissue-sparing, modified transgluteal approach with limited cranial splitting of the gluteus medius muscle reduces hip abductor strength and the risk of approach-related injury to the superior gluteal nerve.

Methods: Thirty-one patients (14 female, 17 male; mean age 53.5 ± 5.2 years) underwent hip resurfacing using a modified transgluteal approach with limited cranial splitting of the gluteus medius muscle. Nerve conduction signals were measured by surface electromyography (EMG), hip abductor strength by isokinetic testing a mean 36.2 months (± 11 mos) after surgery. The unoperated side was used as control.

Results: Surface EMG disclosed no neural lesions of the inferior branch of the superior gluteal nerve. Isokinetics revealed a significant reduction in muscle strength on the operated versus the contralateral side.

Conclusions: Even a limited incision of the gluteus medius muscle resulted in significant impairment of hip abductor strength 2.5 years after surgery.