Development of a Retractor Holding Device to Reduce the Manpower in Total Hip Arthroplasty through Direct Anterior Approach

Direct anterior approach (DAA) for total hip arthroplasty (THA) is a minimally invasive technique. In this approach, two assistants are necessary. We developed a retractor holding device called “Spider arm” to replace an assistant in the contra-lateral side. In this study, we investigated the usefulness of Spider arm in THA through direct anterior approach. 20 hips were operated without Spider arm and 21 hips were operated with Spider arm. The surgery time and the blood loss were compared. The cup position and leg length discrepancy were measured on radiography. There was no statistical significance between two groups in all parameters. No clinical complications were reported. With Spider arm, DAA-THA could be performed by two surgeons without deterioration of the surgery time and blood loss. The accuracy of cup position and leg length discrepancy was not affected. Spider arm can contribute to reducing the manpower in DAA-THA.