Functional recovery after muscle sparing total hip arthroplasty in comparison to classic lateral approach - A three years follow-up study

Background: The muscle sparing total hip arthroplasty had generated a distinguishable interest, in both the patients and the surgeons, but its benefits are still often questioned. The main idea of this study was to compare the functional clinical outcome of the patients operated by the anterolateral approach with a muscle-sparing technique (modified Watson-Jones approach), and the patients operated by modified direct lateral approach without the muscle-sparing technique (Bauer/Hardinge approach).

Methods: The patients (N = 130) were divided into two groups: 68 in a standard method group (STAND) and 62 patients in a muscle sparing surgery group (MSS). The hip flexibility, mobility, the strength of the hip abduction, the pain scale, Harris hip scores, the duration of the hospital stay and the overall satisfaction were measured seven days, three months, one year and three years (in 80 patients) after the surgery. There were no differences in any of the parameters between the groups prior to the procedure.

Results: The statistically significant differences in first three follow-ups (up to one year) were determined between the groups in passive and active hip flexion ability but the hip abduction strength, which is a crucial parameter for functional recovery, and 50 m walk test remained better in MSS group even after three years. Patients, who underwent MSS suffered also less pain, stayed in hospital shorter and were more satisfied with the operation outcome.

Conclusions: The functional recovery in patients treated with muscle sparing method was faster than in patients operated with conventional lateral approach. Based on the results, we could recommend anterolateral muscle sparing approach for a total hip replacement for its faster and fuller functional recovery.