Peripheral nerve injuries, such as axonal injury of the superior gluteal nerve, are rare but debilitating complications that can occur after hip arthroplasty. This case report describes the use of adipose-derived mesenchymal stem cells (MSCs) to treat an axonal injury of the superior gluteal nerve in a 71-year-old patient. After conventional rehabilitation failed, MSC infiltration was chosen and performed with ultrasound (US) guidance. Two months later, the patient showed normalization of electromyography (EMG), indicating full nerve recovery, along with significant improvement in neuropathic pain. The patient also demonstrated a 55% increase in maximum torque and a 9% increase in power during right hip extension in isokinetic evaluation, resulting in improvement of muscle strength and functionality. This case highlights the potential of MSCs in promoting nerve regeneration, suggesting that this approach may accelerate nerve recovery and improve short-term clinical outcomes. Although the results are promising, further studies are needed to confirm the efficacy and safety of this treatment in a larger population. This integrated model of cell therapy and physical rehabilitation represents a significant advance in recovering from complex nerve injuries.