[Morphological characteristics and reduction techniques of sagittal beak-like deformity of head-neck fragment in femoral intertrochanteric fractures].

Objective: To summarize the morphological characteristics of sagittal beak-like deformity of head-neck fragment in femoral intertrochanteric fractures and to investigate the technical skills in fracture reduction. Methods: A clinical data of 31 patients with femoral intertrochanteric fractures between May 2021 and April 2023 was retrospectively analyzed. The fractures had sagittal beak-like deformity of head-neck fragment in all patients. There were 13 males and 18 females, with an average age of 76.2 years (range, 68-83 years). The time from injury to operation was 36-76 hours (mean, 51.2 hours). Fractures were classified as type A1.2 in 10 cases, type A1.3 in 11 cases, type A2.2 in 6 cases, and type A2.3 in 4 cases according to the AO/Orthopaedic Trauma Association (AO/OTA)-2018 classification; and as type A1.3 in 10 cases, type A2.1 in 11 cases, type A2.2 in 6 cases, type A2.3 in 2 cases, and type A2.4 in 2 cases according to a novel comprehensive classification for femoral intertrochanteric fractures proposed by the "Elderly Hip Fracture" Research Group of the Reparative and Reconstructive Surgery Committee of the Chinese Rehabilitation Medical Association. Based on preoperative X-ray films, CT scan and three-dimensional reconstruction, the fractures were classified into two types: type 1 (14 cases), with uncomplicated fracture morphology, severe bone interlocking and (or) soft tissue incarceration; type 2 (17 cases), with severe fracture crushing, obvious dissociation between bone blocks, and severe soft tissue hinge destruction. After the failure of the closed reduction, all patients underwent fracture reduction assisted with instrument via anterior minimal incision and proximal femoral nail antirotation nails internal fixation. The operation time, intraoperative fluoroscopy, intraoperative visible blood loss, length of hospital stay, and incidence of complications were recorded. The fracture reduction quality and stability score were assessed at immediate after operation under fluoroscopy. The fracture healing was evaluated and healing time was recorded by X-ray films. The pain visual analogue scale (VAS) score was performed at 48 hours after operation and Parker-Palmer activity score at 3 months after operation for function evaluation. Results: The operation time was 39-58 minutes (mean, 46.3 minutes); fluoroscopy was performed 13-38 times (mean, 23.5 times) during operation; the intraoperative visible blood loss was 45-90 mL (mean, 65.3 mL). The fracture reduction quality and stability score were rated as good in 29 cases and acceptable in 2 cases. The pain VAS score was 2-6 (mean, 3.1) at 48 hours after operation. Eleven patients developed deep vein thrombosis of the lower limbs after operation. Patients were hospitalized for 6-10 days (mean, 7.3 days). All patients were followed up 5-8 months (mean, 6.5 months). All fractures healed at 3.5-8.0 months after operation (mean, 4.5 months). Parker-Palmer activity score at 3 months after operation was 9 in 28 cases and 6 in 3 cases. Conclusion: The femoral intertrochanteric fracture with sagittal beak-like deformity of head-neck fragment is difficult to manually reduce. The pin combined with cannulated screw insertion to the neck cortex can hold the fragment and assist fracture reduction, which is a simple and effective technique.