Two-Part Intertrochanteric Femur Fractures with Bisection of the Lesser Trochanter: An Irreducible Fracture Pattern

Abstract

Objective: To introduce the clinical features of and surgical techniques for a rare type of irreducible pertrochanteric femur fracture pattern with bisection of the lesser trochanter. Methods: From January 2017 to December 2019, 357 patients with per/intertrochanteric femur fractures underwent surgery by closed reduction and internal fixation, of whom 12 patients were identified with rare preoperative imaging features, the lesser trochanter was almost equally bisected. The main fracture pathoanatomy of these cases included: The anterior fracture line passed along the intertrochanteric line to the medial lesser trochanter and bisected it into 2 equal parts from mid-level of the lesser trochanteric protrusion. The proximal part of the lesser trochanter connected to the head-neck fragment and attached by the psoas major tendon, while the distal part of the lesser trochanter connected to the femoral shaft and attached by the tendon of the iliac muscle. These fractures were irreducible by a closed maneuver and were reduced with limited assistance by some devices, and short intramedullary nails were used for fixation of these fractures. Results: All patients were followed up for an average of 14.2 ± 2.1 months. Clinical fracture union occurred at an average of 10.8 ± 1.5 weeks, while radiographic union occurred at an average of 12.7 ± 1.2 weeks. No cut out of the helical blade was visible on radiographs. The average Parker-Palmer score was 6.9 ± 1.3 (range, 5-9) at the last follow up, including 8 cases rated as excellent, 2 as good and 2 as fair. Conclusion: Two-part pertrochanteric femur fractures with bisection of the lesser trochanter have an irreducible fracture pattern with cortical locking and soft tissue incarceration. Soft tissue release and short cephalomedullary nail fixation for this fracture pattern provide stable fixation and allow early exercise. This treatment appears to have excellent outcomes in the short and medium terms.