Ismailidis P, Kvarda P, Vach W, et al. - This study was undertaken to investigate and evaluate hip abductor muscle strength deficits after total hip arthroplasty (THA) and to ascertain relationships with external factors. For inclusion, studies reporting on hip abductor muscle strength before and/or after THA conducted for osteoarthritis or atraumatic osteonecrosis of the hip were recognized. Researchers carried out to search Embase, Medline, and the Cochrane Central Register of Controlled Trials. They compared muscle strength on the affected side with the healthy contralateral side or to control individuals. A modified Newcastle-Ottawa Scale was applied to assess study quality. The research enrolled 19 studies including a total of 875 individuals. The data exhibited that during 24 months, hip abductor muscle strength deficits may gradually improve after THA possibly without complete recovery. Because high-quality evidence is largely missing, a cautious interpretation of these findings is warranted.