BackgroundThere are ongoing doubts about the effects of the commonly used anterolateral approach (ALA) and posterolateral approach (PLA) for bipolar hemiarthroplasty (BHA) on hip muscle strength after surgery. In this study, it was aimed to evaluate the isokinetic performance of the operated and non-operated hips in patients with femoral neck fractures who underwent BHA with PLA or ALA and to compare the isokinetic performance of the hips and functional results between the two approaches. Materials and methodsForty-one patients who underwent unilateral BHA with PLA or ALA for femoral neck fracture between February 2019 and December 2020 were enrolled. The isokinetic performance of the flexor, extensor, and abductor muscles of the operated and non-operated hips were evaluated by measuring peak torque, total work, and average power. Functional status was assessed using Harris Hip Score and Short Form 36. ResultsThe patients were divided into two groups; those operated with PLA (n=22) and with ALA (n=19). The groups had similar demographic and clinical characteristics. All isokinetic parameters of the operated hips did not differ between the groups (all p>0.05). In both groups, all isokinetic parameters were significantly lower in the operated hips than in the non-operated hips. ConclusionAlthough there are debates about potential extensor muscle injury with PLA and potential abductor muscle injury with ALA, this study showed that functional results and the isokinetic performance of both approaches were not different.