Introduction Hip resurfacing (HR) is intended to preserve the femoral bone stock during primary arthroplasty. On the other hand, little has been reported regarding the intraoperative need of bone reconstruction for extended acetabular defects during hip resurfacing revision. Thus, the aim of the presented study was to identify whether there is an increased need for acetabular bone reconstruction in HR revision surgery.Materials and methodsWe analyzed the data of 38 patients who underwent 39 conversions from a HR to a total hip arthroplasty (THA). Acetabular bone defects and the respective revision technique were compared against a temporary cohort of patients undergoing revision surgery of a conventional THA.ResultsIn 29 HR patients revision required either autogenous or allogenous impaction bone grafting to adequately manage acetabular host bone degradation. In 10 cases additional implantation of a reinforcement device was necessary. Compared to the THA cohort revision of failed HR is associated with a significantly increased risk of higher grade bone defects (Paprosky classification) and extended acetabular reconstruction (p < 0.05).ConclusionsThis study provides evidence that revision of failed HR devices is associated with an increased risk for extensive acetabular defects. Furthermore, the preoperative radiographic assessment of HR devices often underestimates the intraoperative acetabular defect. Surgeons should be aware of this fact not to technically underestimate HR revision procedures.