Conversion Hip Arthroplasty Using Standard and Long Stems after Failed Internal Fixation of Intertrochanteric Fractures

Objective Failed internal fixation of intertrochanteric fractures (FIF-ITF) is often treated by conversion hip arthroplasty (CHA). This study aimed to evaluate the results and complications of using standard and long femoral stems in this operation. Methods This retrospective, multi-center study enrolled 31 total hip arthroplasty (THA) and 23 hemiarthroplasties (HA) cases (30 women, 24 men; mean age 76 years) after FIF-ITF between 2012 and 2019, divided into two groups: standard stem group (n = 20) and long stem group (n = 34). The initial internal fixation includes 38 cases of proximal femoral nail anti-rotation (PFNA), eight cases of the dynamic hip screw (DHS), and eight cases of locking proximal femoral plate (LPFP). The indications for CHA included 38 cases of failure of fixation, seven cases of nonunion, and nine cases of avascular necrosis or posttraumatic osteoarthritis. Perioperative data and complications related to fracture and operation were collected, and preoperative and postoperative clinical and radiological data were analyzed. Clinical outcomes were assessed using Harris hip score (HHS) and 36-item Short Form survey (SF-36: including physical function (PF) score and body pain (BP) score). Statistical analyses were performed using the chi-square or Fisher's exact test, and the 2-sample t-test or Wilcoxon rank sum test. Results At an average of 5.6 years with a minimum of 2 years follow-up. A significant overall surgeon-related complication rate was detected (27.8% [15/54]), five cases had an intraoperative femur fracture, one case had a late periprosthetic femoral fracture, two cases had a stem penetration, one case had a cement leakage, and two patients had an early postoperative dislocation, one infection and three cases of stem loosening or subsidence. Long stems had an increased risk of complication (13/34) compared to standard stems (2/20) (P = 0.031). The operation time and blood loss in the long stem group were higher than those in the standard stem group (P = 0.002; 0.017). HHS and SF-36 significantly improved in both groups from preoperative to the final follow-up and did not present significant differences at the final follow-up (P > 0.05). Conclusion CHA following FIF-ITF showed a successful mid-term clinical result, long stem arthroplasty should be approached with caution for the risks of higher complication rate, especially intraoperative femoral fractures.

Automated summary

Conversion hip arthroplasty showed successful mid-term clinical results in cases of failed internal fixation of intertrochanteric fractures. However, long stem arthroplasty carries a greater risk of complications, particularly intraoperative femur fractures.