# Avascular Necrosis of the Femoral Head Following Sliding Hip Screw Fixation in the Context of Recent Contralateral Vascular Surgery: A Report of a Rare Case

## TL;DR

A rare case of avascular necrosis of the femoral head occurred after hip screw fixation and contralateral vascular surgery, highlighting a possible new clinical association.

## Contribution

This report identifies a rare association between contralateral vascular surgery and avascular necrosis following hip screw fixation.

## Key findings

- Avascular necrosis occurred in a femoral head previously stabilized with a sliding hip screw.
- The patient had recently undergone contralateral femoro-popliteal bypass surgery.
- Histopathology confirmed extensive bone marrow necrosis consistent with AVN.

## Abstract

Avascular necrosis (AVN) of the femoral head is a rare complication following extracapsular hip fracture fixation with a sliding hip screw (SHS). The femoral head is primarily supplied by the medial femoral circumflex artery, and this circulation is typically preserved in intertrochanteric fractures, explaining why AVN is rarely observed in this setting. AVN is more often associated with trauma or systemic risk factors such as corticosteroid use or chronic alcohol abuse. We report a rare case of AVN in a previously healed intertrochanteric fracture treated with SHS, occurring after contralateral femoro-popliteal bypass surgery. A woman in her sixth decade presented with acute right hip pain one year after SHS fixation for an intertrochanteric femoral fracture. She had recently undergone contralateral femoro-popliteal bypass. Radiographs demonstrated femoral head collapse with screw penetration into the acetabulum, confirmed by CT. The patient underwent SHS removal and hybrid total hip arthroplasty. Histopathology revealed extensive coagulative necrosis of bone marrow with saponification and fibrosis, consistent with AVN. This case highlights a potential association between major vascular surgery and contralateral femoral head AVN after SHS fixation. Clinicians should maintain a high index of suspicion when new-onset hip pain develops following vascular procedures, as early recognition may offer an opportunity for joint-preserving management before irreversible collapse occurs.