Purpose: To characterize muscle recovery following total hip arthroplasty (THA) combining genetic adaptations in the affected leg with objective function and body composition assessment. Methods: Preoperatively and at six weeks postoperatively, objective function was assessed by: maximal voluntary contraction of the operated leg quadriceps (MVCOLQ) in Newtons (N), 30 s chair sit-to-stand (ST), and six-minute walk test (6MWT), with lean mass of the operated leg estimated by dual energy X-ray absorptiometry (DEXA). Genetic adaptations were assessed from vastus lateralis (VL) biopsies by quantitative polymerase chain reaction (qPCR) analysis of markers of hypertrophy (FOS, calpain2 (CAPN2)), atrophy (20 s proteasome alpha subunit 7 (PSMA7), cathepsin L2 (CTSL2), inflammation (Tumour necrosis factor alpha (TNF-α), Interleukin-6 (IL-6)) and lipid metabolism (lipoprotein lipase, LPL and peroxisome proliferated activated receptor gamma (PPARAG). Results: 14 patients were recruited. At six weeks, no significant differences, relative to preoperative values, were noted in either objective function or leg lean mass. Markers for hypertrophy were increased (FOS +1463%, p = 0.016), with atrophy (PSMA7 -44.8%, p = 0.016; CTSL2 -42.5%, p = 0.050), inflammation (TNF -29.6%, p = 0.023) and lipid metabolism markers showing a decreasing trend (LPL -42.45%, p = 0.016). Conclusion: The initial post-THA intramuscular environment appears supportive of anabolism. However, this is not reflected in objective function or lean mass measures at six weeks, suggesting longer duration may be required for physiological adaptation to occur.