Abstract
BACKGROUND: There is no consensus of whether to use a short or long intramedullary nail (IMN) in the treatment of trochanteric and subtrochanteric fractures. METHODS: In this retrospective cohort study, we analyzed 17,606 trochanteric and subtrochanteric fractures treated with an IMN registered in the Norwegian Hip Fracture Register from 2008 to 2022. The primary outcome was overall 1-year reoperation risk, and secondary outcomes were reoperation risk for specific causes and 1-year mortality for short IMNs (SIMNs) and long IMNs (LIMNs) and to compare 1-year reoperation risk for short and long versions of the 2 most used brands (Gamma3 and TRIGEN INTERTAN). Cox regression analyses adjusted for age, sex, and ASA class and instrument variable (IV) analyses with operation year and hospital as instrument were performed to calculate hazard rate ratios (HRRs). RESULTS: LIMNs had a statistically significant higher reoperation risk than SIMNs in A1 fractures in the IV analysis. No other statistically significant differences in overall 1-year reoperation risk or 1-year mortality between SIMNs and LIMNs were found for any of the fracture types. Infection was a more frequent cause of reoperation after LIMNs (HRR, 2.82 [95% confidence interval [CI], 1.53-5.20]) while peri-implant fractures were less common for LIMNs (HRR, 0.38 [95% CI, 0.20-0.75]) compared with SIMNs. No statistically significant differences were found in reoperation risk between short and long Gamma3 nails or TRIGEN INTERTAN nails. CONCLUSION: SIMNs performed equal or better than LIMNs for all types of trochanteric and subtrochanteric fractures. LEVEL OF EVIDENCE: Therapeutic Level III. See instructions for Authors for a complete description of levels of evidence.