A Comparison of the Effectiveness of Different Fixation Strategies in Pediatric and Adolescent Subtrochanteric Femur Fractures

INTRODUCTION: Subtrochanteric femur fractures account for 4% to 10% of all pediatric femur fractures. In adults, managing these fractures can be challenging due to loss of reduction and nonunion. Limited data exist on pediatric outcomes related to implant selection. This study evaluates the radiographic and functional outcomes of subtrochanteric femoral fracture fixation strategies. METHODS: Patients ≤18 years old treated operatively for subtrochanteric femoral fractures, defined as fracture lines starting ≤10% of the femoral length distal to the lesser trochanter, between 2015 and 2023, were included. Medical records provided demographics, fracture characteristics, management, radiographic measurements, and outcomes. Radiographic healing was defined as bridging callus formation in 3 of 4 cortices. Angulation and displacement were measured at presentation and at follow-up visits. Complications, including painful hardware and malalignment (>10 degrees angulation in AP or lateral planes), were noted. Patient-Reported Outcomes Measurement Information System (PROMIS) scores were collected. RESULTS: We included 31 operatively managed subtrochanteric femur fractures with a median follow-up of 13.0 months (range: 0.6 to 127.0). Flexible nails were used in 48% of cases, rigid nails in 32%, and plating in 19%. Average ages were 6, 13, and 9 years, respectively (P10 degrees was most common in the flexible nail group (P=0.046). Radiographic healing was not different across treatment methods. After 4 weeks postoperatively, PROMIS pain and mobility scores were similar across treatment groups (P>0.05). At 3 months postoperatively, malalignment >10 degrees was present in 31% of flexible nail cases, 33% of plate cases, and 0% of rigid nail cases (P=0.25). CONCLUSIONS: Rigid nails, flexible nails, and plate fixation all result in radiographic healing and functional improvement in pediatric subtrochanteric femur fractures. Although flexible nails are associated with higher malalignment rates at 6 weeks, these rates were comparable across treatment groups by 3 months. Flexible nails remain a viable option in this population. Ultimately, the fixation strategy should be guided by patient-related factors rather than the subtrochanteric pattern alone. LEVEL OF EVIDENCE: Level III-therapeutic studies; investigating the results of treatment.