# Survivorship and risk factors for revision after total hip arthroplasty in patients 30 years and younger: a cohort study from the German arthroplasty register

## TL;DR

This study examines hip replacement outcomes in patients under 30, finding a 4.6% revision rate and identifying pediatric hip disease as a key risk factor.

## Contribution

The study provides new insights into THA survivorship and revision risk factors in patients aged 30 or younger using a national registry.

## Key findings

- The cumulative revision rate at 8 years was 4.6% (CI 2.8–7.3) for uncemented THA in young patients.
- Pediatric hip disease, including Perthes and pelvic osteotomy, significantly increased revision risk.
- Infection was the most frequent cause of revision, accounting for 0.7% of cases.

## Abstract

Total hip arthroplasty (THA) in young patients is rare but increasingly performed. We aimed to analyze implant survivorship and risk factors for revision in patients aged 30 years or less after THA based on the German Arthroplasty Registry (EPRD).

Kaplan–Meier survival analysis and Cox proportional hazard models were used to analyze the EPRD dataset from 2013 to 2023 for factors associated with increased risk of revision. The primary outcome was first revision operation.

1,622 primary THAs in 1,452 patients were analyzed. The mean age was 26 years (range 11–30), 908 (56%) of whom were male. The most frequent diagnosis was secondary osteoarthritis (1,146, 72%), followed by osteonecrosis (357, 22%), and hip dysplasia (53, 3.2%). Of all THAs, 1,601 (99%) were uncemented, and 1,574 (97%) received ceramic heads. The average follow-up period was 3.7 years (range 0–10.6). 47 hips were revised with a cumulative revision rate (CRR) at 8 years of 4.6% (95% confidence interval [CI] 2.8–7.3). The most frequent revision cause was infection in 11 cases (0.7%). Increased revision risk was associated with pediatric hip disease for those with prior surgery for Perthes, HR 4.3 (CI 1.9–9.6), pelvic osteotomy HR 2.8 (CI 1.1–7.5), and a primary diagnosis of hip dysplasia, HR 3.4 (CI 1.3–8.5).

Uncemented THA in young patients demonstrated a revision rate of 4.6% (CI 2.8–7.3), which we believe is a satisfactory mid-term survival. Patients with pediatric hip disease present the highest risk of revision.