# Treatment of hip instability after total hip replacement with pelvic osteotomy using a modified Stoppa approach

## TL;DR

This paper presents a case study of a patient with recurrent hip dislocation after total hip replacement, successfully treated with pelvic osteotomy using a modified Stoppa approach without component revision.

## Contribution

The novel use of pelvic osteotomy via a modified Stoppa approach to treat hip instability without revising implant components is highlighted.

## Key findings

- Pelvic osteotomy successfully reduced acetabular inclination in a patient with recurrent hip dislocation.
- The patient showed significant clinical improvement with no dislocation recurrence at two years.
- Component revision was avoided, preserving bone stock and avoiding complications from cup extraction.

## Abstract

Hip dislocation remains a significant complication following total hip arthroplasty, even though its incidence has decreased. While closed reduction is typically performed for early dislocations, delayed or chronic dislocations often necessitate acetabular or femoral component revision.

This document describes the treatment of hip dislocation in a 56-year-old patient through pelvic osteotomy without component revision. An acetabular component malposition was identified, exhibiting an 80-degree inclination and 20-degree cup anteversion. Owing to limited bone stock, a modified Stoppa approach was used for pelvic osteotomy to reduce acetabular inclination. The patient displayed remarkable clinical improvement, achieving a Harris Hip Score of 85 at the two-year check-up with no signs of dislocation.

Recurrent hip dislocation is difficult to manage. It frequently necessitates component revision, presenting a challenge due to issues with cup extraction and limited bone stock. Preoperative detection of loosened components is crucial. If it goes undetected, the extraction process can result in bone loss, potentially leading to pelvic insufficiency.

Successful revisions of hip arthroplasties can be achieved with geometric modifications to the pelvis.

•Despite numerous technological advances, hip dislocation remains an essential sequela of THA.•The most challenging aspect of surgical treatment is removing the acetabular cup or femoral stem.•The patient presented to us due to a fourth hip dislocation that had occurred one month previously•We assessed our patient with insufficient acetabular walls and whether ring and cage reconstruction would be needed.•Pelvic osteotomy serves as a geometrical alteration for restoring normal biomechanics without component loosening.

Despite numerous technological advances, hip dislocation remains an essential sequela of THA.

The most challenging aspect of surgical treatment is removing the acetabular cup or femoral stem.

The patient presented to us due to a fourth hip dislocation that had occurred one month previously

We assessed our patient with insufficient acetabular walls and whether ring and cage reconstruction would be needed.

Pelvic osteotomy serves as a geometrical alteration for restoring normal biomechanics without component loosening.