Complete Joint Capsule-Preserving Posterior Approach in Hemiarthroplasty for Femoral Neck Fractures: A Technical Note and Learning Curve Analysis of Trainee Surgeons

<b>Introduction:</b> The posterior approach is widely used in hemiarthroplasty for femoral neck fractures. However, it has a high dislocation rate. In hemiarthroplasty, the joint capsule is commonly incised. This study aimed to identify a posterior surgical technique that completely preserves the joint capsule without incision and the use of special devices to remove the head, perform a trial, and place an implant. Further, the learning curves (LCs) of trainee surgeons and the associated complications of the posterior approach were evaluated via a retrospective case series. <b>Materials and Methods:</b> The LCs of trainee surgeons for surgical duration and volume of intraoperative blood loss in 60 cases were examined. The surgical procedures were conducted by three trainee surgeons for femoral neck fractures at a single institution between September 2018 and June 2021. Each surgeon consecutively performed 20 surgical procedures. Each surgeon's cases were divided into four groups, with 15 cases each: 1-5, group A; 6-10, group B; 11-15, group C; and 16-20, group D. Then, these cases were analyzed. Surgery-related complications, such as dislocation, femoral fractures, paralysis, and infection were investigated. <b>Results:</b> The four groups significantly differed in terms of the median operative duration (<i>P</i> = 0.017). In particular, there was a significant difference between groups A and C (<i>P</i> = 0.007) and between groups A and D (<i>P</i> = 0.006). There was an LC for the surgical duration. In 10 cases, the surgical duration was shorter. However, there was no significant difference in the volume of intraoperative blood loss among the four groups. None of the patients presented with dislocation or major complications. <b>Discussion and Conclusions:</b> An LC was observed for the surgical duration in 10 cases among the trainee surgeons. Moreover, the volume of intraoperative blood loss did not significantly increase during the LC period.