Retrograde Nailing for Extremely Proximal Fractures of the Femoral Shaft.

OBJECTIVES: To report the results of retrograde intramedullary nailing (RIMN) for the treatment of extremely proximal femur fractures. DESIGN: Retrospective cohort study. SETTING: Level I trauma center. PATIENTS/PARTICIPANTS: 63 patients with femoral shaft fractures involving the anatomic region within 10 centimeters of the inferior border of the lesser trochanter, which were treated with retrograde intramedullary nailing. INTERVENTION: Retrograde intramedullary femoral nail. MAIN OUTCOME MEASUREMENTS: Time to union, nonunion, malunion, and unplanned reoperation. RESULTS: Between 2009 and 2020, 63 fractures were followed up to fracture union, reoperation, or a minimum of 1 year clinically. The mean follow-up was 32 months, and 48 (76%) of the patients were followed up beyond 1 year clinically. The mean patient age was 34 years (range 18-84 years), and the mean BMI was 27 (range 14-45) kg/m 2 . Forty (64%) patients were polytraumatized. Clinical and radiographic union was achieved in 59 (94%) fractures after index operation at a mean time to union of 22 weeks (range 9-51 weeks). Delayed union requiring nail dynamization occurred in 1 (2%) instance. Malreduction was noted in 1 (2%) patient with a 12-degree flexion deformity that resulted in nonunion. In total, there were 3 (5%) nonunions requiring revision surgery, 1 treated with retrograde exchange nailing and 2 revised to cephalomedullary nails; all were united after revision. CONCLUSIONS: Retrograde intramedullary nailing can be an effective treatment strategy for extremely proximal femur fractures when necessary. Our series demonstrated a high rate of union and a low rate of malalignment and complications. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.