Multiple sclerosis (MS) is a chronic degenerative disease of the central nervous system (CNS) characterized by demyelination and axonal degeneration in the brain and spinal cord, which are caused by an immune-mediated inflammatory process. These changes lead to motor dysfunction, including muscle spasticity and impaired coordination [1,2]. Furthermore, motor deficits can complicate postoperative rehabilitation and affect the outcomes of different surgical procedures. Femoral neck fractures, often the result of falls and/or trauma, are common in patients with MS, particularly those with severe neurological impairment [[3], [4], [5], [6]–7]. The treatment of displaced femoral neck fractures typically includes either total hip arthroplasty (THA) or hemiarthroplasty, both of which aim to restore hip function, ambulatory function, and alleviate pain [[8], [9], [10], [11], [12], [13], [14]–15]. Indications for each mostly depend on patient comorbidities and the presence of ambulatory status and cognitive functioning. It is unclear whether these procedures are associated with different rates of implant complications, including hip dislocations, aseptic loosening, periprosthetic joint infections (PJIs), and the need for revision surgery in non-demented patients with concomitant MS and femoral neck fractures.

The goal of THA is to restore joint function and alleviate pain while providing long-term stability [16,17]. In contrast, hemiarthroplasty involves only replacing the femoral head with a prosthetic component, leaving the native acetabulum and labrum intact. Hemiarthroplasty is considered a less invasive option, with shorter operative times and potentially lower complication rates, particularly in older or frailer patients [18,19].

Given the unique challenges presented by MS patients devoid of cognitive deficits, including increased muscle tone and spasticity, it is important to evaluate whether THA or hemiarthroplasty is more prone to complications in this patient population. This study aimed to compare the demographics of patients who underwent THA versus hemiarthroplasty and evaluate the incidence and odds of implant-related complications and revision surgery between patients with MS undergoing THA and those undergoing hemiarthroplasty for femoral neck fractures.