Does tenodesis of tensor fascia latae with hip abductors after proximal femoral resection and modular endoprosthetic reconstruction lead to functional improvements?

Abstract

Trendelenburg gait is a common consequence of proximal femoral oncologic resection. To mitigate limping, tensor fascia latae (TFL) tenodesis is employed by suturing the muscle to the abductor mechanism, repaired to the trochanteric portion of the endoprosthesis. Objective functional evaluation of this technique has not been conducted. This study aimed to determine (1) whether the procedure induces tensor fascia latae hypertrophy, (2) its impact on functional outcomes and (3) its effect on gait patterns. Sixteen patients who underwent proximal femoral resection and modular endoprosthesis reconstruction were assessed via computed tomography scans at least 1 year post-operatively for TFL and hip abductor hypertrophy and fatty infiltration. Patients were separated into two groups based on the presence or absence of TFL hypertrophy. Patient-related outcomes were evaluated with questionnaires, and a subset of seven patients underwent hip abductor strength measurement and gait analysis to assess objective function. Gait analysis included kinematics as well as electromyography. At 1 year, half of the cohort demonstrated TFL hypertrophy. A trend towards improved functional scores was observed in the hypertrophy group. Hip kinematics indicated a greater adduction (max of 7.2 ± 4.1° vs. 2.8 ± 2.6°, 88% difference) in the hypertrophy group, resulting in an increased pelvic drop during single-limb support (5.2 ± 3.1° in the hypertrophy group and 3.4 ± 3.7° in the no hypertrophy group, 42% difference). Gluteus medius activation tended to be slightly greater during the stance phase for the no hypertrophy group, while the TFL was most activated in the hypertrophy group in the same period. The TFL tenodesis led to satisfactory functional outcomes for patients with proximal femoral reconstruction, whether they developed hypertrophy or not. TFL hypertrophy was not associated with a more favourable gait pattern, despite positive self-evaluated function. Level IV.