Primary versus conversion hemiarthroplasty after failed internal fixation for intertrochanteric fractures: a multicenter retrospective study

Conversion hemiarthroplasty (CHA) following failed internal fixation of intertrochanteric fractures is a technically demanding procedure, yet direct comparisons with primary hemiarthroplasty (PHA) are scarce. This study compared the perioperative characteristics, postoperative complications, survival outcomes, and mid-term clinical outcomes between patients undergoing PHA and those requiring CHA. This multicenter retrospective study included 147 patients who underwent hemiarthroplasty for intertrochanteric fractures at three tertiary hospitals between March 2009 and September 2025, including 42 who underwent PHA and 105 who underwent CHA after failed internal fixation. Perioperative characteristics, postoperative complications, 1-year mortality, and postoperative pain and hip function were compared between groups. Implant-related variables, including femoral stem type, fixation method, and greater trochanter reconstruction, were also evaluated. Kaplan-Meier analysis and multivariable Cox regression were performed to assess survival outcomes and factors associated with complication-free survival. Baseline characteristics were broadly comparable between the groups. Compared with PHA, CHA was associated with significantly longer operative time, greater intraoperative blood loss, longer hospital stay, higher postoperative VAS scores, and lower postoperative HHS values at the 24-month follow-up (all P < 0.0001). The overall postoperative complication rate was also significantly higher in the CHA group. By contrast, intraoperative transfusion, limb-length discrepancy, and 1-year mortality were numerically more frequent in the CHA group, but these differences were not statistically significant. CHA more often required long stems, cemented femoral components, and plate-and-screw fixation of the greater trochanter. Kaplan-Meier analysis showed significantly worse overall survival and complication-free survival in the CHA group, whereas multivariable Cox regression identified a higher age-adjusted Charlson Comorbidity Index as an independent predictor of poorer complication-free survival. Conversion hemiarthroplasty following failed internal fixation of intertrochanteric fractures involved greater operative complexity and resulted in worse postoperative pain and function than primary hemiarthroplasty. The postoperative course was also less favorable. In addition, overall survival and complication-free survival differed significantly between the groups.