# Proximal fragment perfusion following hip arthroplasty with subtrochanteric shortening osteotomy in cases with severe developmental dysplasia of the hip

## TL;DR

This study examines blood flow changes in the hip area after surgery for severe hip dysplasia and finds that healing rates remain high.

## Contribution

The study provides new insights into blood flow and healing outcomes after subtrochanteric shortening osteotomy in severe developmental dysplasia of the hip.

## Key findings

- High union rates (96.2% after one year) were observed in patients undergoing subtrochanteric shortening osteotomy.
- Blood flow in the proximal femoral segment was not significantly reduced following the surgery.
- Tracer uptake ratios between the operated and contralateral sides showed no significant differences.

## Abstract

The changes in proximal femoral blood flow occurring after reconstructive surgery for Crowe types III–IV developmental dysplasia of the hip (DDH) and their impact on healing remain unclear. In the present study, blood flow around the osteotomy site is evaluated with particular focus on the proximal segment in patients who underwent subtrochanteric shortening osteotomy and hip arthroplasty. To this end, single-photon emission computed tomography (SPECT/CT) scans were conducted to evaluate changes in proximal blood flow and to assess the impact on union rates and potential complications.

A retrospective analysis was conducted of 26 hips from a total of 20 patients with Crowe types III or IV DDH who underwent hip arthroplasty with subtrochanteric shortening osteotomy between July 2017 and September 2022. Planar, whole-body, and SPECT/CT images were reviewed by two nuclear medicine physicians, and the tracer uptake between the greater and lesser trochanters was assessed visually and quantitatively.

Assessed in the study were 26 hips of 20 patients (mean age 51.5 ± 8.8 years; 80.8% female) with a mean follow-up of 20.1 ± 10.1 months. Of the total, 14 hips were right-sided and 12 were left-sided; five and 21 were Crowe types III and IV, respectively. The union was timely (≤6 months) in 16 hips (61.5%), delayed in nine hips (34.6%), and nonunion in one hip (3.8%). After one year, 25 hips (96.2%) had achieved union. The mean femoral shortening was 3.8 ± 1.2 cm. SPECT/CT analysis revealed a mean SUVmean of 3.5 ± 1.2 on the operated side versus 3.3 ± 1.2 on the contralateral side (p = 0.350). The tracer uptake ratios for greater trochanter/sacrum and greater trochanter/distal femur were similar between sides (p = 0.425 and 0.674, respectively).

In patients with Crowe types III–IV DDH undergoing total hip arthroplasty, shortening osteotomies and soft tissue releases do not appear to significantly reduce vascularity or perfusion of the proximal osteotomy fragment. In our cohort, high union rates were observed.