The Role of Targeted Rehabilitation in Enhancing Recovery After Total Hip Arthroplasty with Anterior Minimally Invasive Surgery Approach: A Retrospective Pilot Study

Background: Hip osteoarthritis is a highly prevalent degenerative condition and a leading indication for total hip arthroplasty (THA). As anterior approaches have gained popularity, optimizing postoperative rehabilitation according to the muscles involved in recovery has become increasingly relevant. However, evidence regarding muscle-specific rehabilitation following the Anterior Minimally Invasive Surgery (AMIS) approach remains limited. Objectives: This study aimed to evaluate whether rehabilitation protocols specifically targeting the hip flexors or abductors could improve postoperative functional recovery compared with standard rehabilitation following AMIS THA. Methods: This retrospective single-center study included 29 patients aged 50–80 years with BMI < 30 kg/m2 undergoing unilateral THA through the AMIS approach. The cohort included 14 men and 15 women. Patients were non-randomly allocated according to clinical and organizational factors to standard rehabilitation (ST; n = 10), a hip flexor-focused protocol (SP1; n = 10), or a hip abductor-focused protocol (SP2; n = 9). Postoperative recovery was evaluated using clinical, functional, and patient-reported outcome measures. Rehabilitation was supervised by physiotherapists. Outcomes included goniometric hip range of motion, dynamometer-measured hip flexor and abductor strength, Timed Up and Go (TUG), Visual Analogue Scale (VAS), Harris Hip Score (HHS), Hip Disability and Osteoarthritis Outcome Score (HOOS), and SF-12. Longitudinal outcomes were analyzed using two-factor models assessing time, rehabilitation group, and their interaction, with post hoc comparisons where appropriate. Statistical significance was set at p < 0.05. Results: Of the 29 initially enrolled patients, 26 completed the study assessments and were included in the final analysis (ST, n = 9; SP1, n = 10; SP2, n = 7). Significant improvements over time were observed for hip flexion and internal rotation ROM, abductor strength, TUG, VAS, HOOS, and HHS. No consistent superiority of either targeted protocol over standard rehabilitation was identified. Postoperative improvements in hip range of motion, muscle strength, mobility, pain, and functional performance were observed over time across the study cohort. Although no protocol demonstrated statistically significant superiority in range of motion or functional outcomes, all three groups showed postoperative improvement over time following AMIS THA. Conclusions: All rehabilitation groups improved during postoperative recovery, but neither the flexor- nor abductor-focused protocol demonstrated superiority over standard rehabilitation. Given the small sample size and non-randomized design, these findings are preliminary and hypothesis-generating and require confirmation in adequately powered randomized studies. Because the targeted protocols also involved a greater overall number of prescribed exercises, the present design cannot distinguish the effects of muscle-specific targeting from those of greater exercise exposure.