Predictive value of preoperative gluteus and iliacus muscle volumes for patient-reported outcomes following total hip replacement: a three-dimensional volumetric analysis.

Abstract

Introduction: This study aimed to investigate the relationship between hip muscle mass and patient-reported outcomes (PROs) after total hip arthroplasty (THA) surgery for hip disease using 3D volumetric measurements of the gluteus muscle group and iliac muscle.

Materials and methods: Between January 2020 and December 2021, 85 patients who had undergone unilateral THA for osteoarthritis or osteonecrosis of the femoral head were enrolled. Using a 3D modeler program, automatically generated 3D reconstructed images of the hip muscles were obtained, and volumetric measurements were performed. Both unadjusted and height (m²)-adjusted muscle volumes of the gluteus maximus (unadjusted volume: GmaxV; adjusted volume: GmaxI), gluteus medius (unadjusted volume: GmedV; adjusted volume: GmedI), gluteus minimus (unadjusted volume: GminV; adjusted volume: GminI), and iliacus (unadjusted volume: IliacV; adjusted volume: IliacI) muscles were measured on the affected side and both sides. Pearson correlation analysis between muscle volumes and postoperative 12-month PROs were performed.

Results: The preoperative Gmax volume on the affected side was significantly associated with post-operative PROs, especially mHHS (GmaxV: p = 0.026; GmaxI: p = 0.005) and UCLA scores (GmaxV: p = 0.006; GmaxI: p = 0.002). For measurements on both sides, Gmed volume was the sole index showing a significant correlation with postoperative UCLA scores (GmedV: p = 0.023; GmedI: p = 0.043).

Conclusions: The current study suggests that preoperative gluteus muscle volume may have predictive value for postoperative PROs of hip disease patients who have undergone THA surgery.