Case Report: Trans-Articular External Skeletal Fixation of the Hip for a Highly Comminuted Juxta-Articular Fracture of the Proximal Femur Caused by Gunshot Injury in a Cat.

Hyun-Jung Han,Kyeongpung Lee,Hun-Young Yoon

doi:10.3389/fvets.2021.652847

Abstract

This report describes a novel surgical technique for trans-articular external skeletal fixation (TA-ESF) of the hip to stabilize a rare, highly comminuted juxta-articular fracture of the proximal femoral segment involving the metaphysis and diaphysis in a cat. A 2-year-old, castrated male, Korean shorthair cat was admitted for a left femoral fracture caused by gunshot injury. Radiographs and computed tomography (CT) scans revealed a highly comminuted proximal femoral diaphyseal fracture that involved the femoral neck and the greater trochanter. The left femoral head was intact on CT. Under fluoroscopic guidance, an intramedullary Steinmann pin was placed to align the femur, and five positive-profile, end-threaded pins were placed in the left hemipelvis and distal femur. A triangulated frame of connecting bars was constructed using Steinmann pins and epoxy resin for TA-ESF. This secured the pins placed in the pelvis and femur as well as the intramedullary pin, providing proximal femoral stabilization by trans-articular fixation of the hip. The cat began placing weight on the left pelvic limb 4 days postoperatively, and progressively obtained near-normal limb function by day 112. The TA-ESF was partially dismantled to a linear tie-in construct on day 64 and was completely removed on day 161. Final radiographs on day 161 revealed lack of bone healing in the proximal segment, especially femoral head and neck, despite functional recovery of the injured leg. At one year postoperatively, the cat had normal limb function without any noticeable complications. On follow-up 29 months after surgery, the owner reported that the cat had normal limb function without any noticeable complications. Despite insufficient bone healing in the cat, TA-ESF of the hip allowed for satisfactory functional recovery of this challenging juxta-articular fracture of the proximal femur, which was not amenable to stabilization with a traditional non-load-sharing fixation system.

Highlights

Surgical stabilization of highly comminuted fractures of the proximal or distal juxta-articular bones has rarely been reported in veterinary literature
Since the trans-articular fixation using external skeletal fixation (ESF) preserves the joint during the procedure [4,5,6,7,8], it is valuable for temporary immobilization of the associated joint without the articular invasion
Despite the lack of fracture healing, TAESF provided a satisfactory clinical outcome, including successful biological osteosynthesis and functional recovery of a comminuted fracture of the proximal femur caused by gunshot injury in this cat

Summary

INTRODUCTION

Surgical stabilization of highly comminuted fractures of the proximal or distal juxta-articular bones has rarely been reported in veterinary literature. The day after surgery, the cat would not place weight on the left pelvic limb, which was very painful, and could not tolerate palpation of the left femur (Supplementary Video 1). By postoperative day 32, the cat had progressed to weightbearing lameness It still had a distinct head nod and mild pain on palpation of the left femur. The first and third connecting rods were cut near the area of linkage using a saw and pin cutter, while avoiding impairment of the remaining linear tie-in frame (Figure 4B) This disassembly re-established motion in the left coxofemoral joint. The cat showed more pain immediately after disassembly than before disassembly of the frame It still placed weight on the left pelvic limb with notable lameness and a distinct head nod (Supplementary Video 2). The owner reported that the cat represented normal gait without any noticeable pain and lameness (Supplementary Video 5)

DISCUSSION

Findings

CONCLUDING REMARKS

ETHICS STATEMENT