Femur Fractures Distal to Long and Short Cephalomedullary Nails: A Comparative Multicenter Study.

Introduction: Cephalomedullary nails (CMNs) are commonly used to treat intertrochanteric hip fractures. Subsequent fractures distal to an existing CMN are a challenging complication with patterns and management that vary based on nail length. Whether short or long CMNs allow for less complicated surgical revision or better postoperative outcomes is unknown. The aim of this study was to compare the treatment strategies and outcomes of fractures distal to short versus long CMNs.

Methods: This multicenter retrospective study identified 58 patients who underwent surgical management of a fracture distal to a short CMN (n = 30) or long CMN (n = 28) following low-energy trauma between 2005 and 2022. Demographics, injury characteristics, and perioperative outcomes were compared between the cohorts. Multivariable linear regression was used to compare outcomes of exchange CMN versus open reduction and internal fixation (ORIF).

Results: Most fractures below short CMNs were managed with exchange CMN or a nail-plate combination (58%), whereas most fractures below long CMNs were treated with ORIF (89%). No differences were found between short and long CMN revision surgery in terms of surgical time, estimated blood loss, use of fluoroscopy, transfusion, length of stay, or postoperative complications. Compared with ORIF, exchange CMN was associated with similar odds of needing a transfusion and experiencing a postoperative complication but a greater likelihood of being permitted to bear weight as tolerated after surgery (odds ratio 43.1; 95% confidence interval 4.1 to 457.6) and being discharged home (odds ratio 27.3; 95% confidence interval 2.0 to 367.6).

Discussion: This is the largest series of fractures distal to a CMN to date. Surgical morbidity, surgical time, and use of fluoroscopy were similar in patients with short and long CMNs. Although managing these injuries with exchange CMN was associated with comparable morbidity to ORIF, a notable functional advantage was observed with exchange CMN by facilitating earlier full weight-bearing and discharge home.