- Design
- Retrospective consecutive single-surgeon case series, competing-risks analysis
- Population
- 75 hips in 63 patients with acetabular dysplasia, operated 1984–1987
- Primary outcome
- Survivorship free from conversion to total hip arthroplasty
- Effect
- 27% (95% CI 12–39%) at 40 years; Tönnis grade HR 2.3, positive impingement test HR 3.9
The first 75 hips (63 patients) treated with periacetabular osteotomy for acetabular dysplasia, operated on by the procedure's originator in Bern between 1984 and 1987, have now been followed for 40 years. Median age at surgery was 26 and most patients were women.
Survivorship free from conversion to total hip replacement was 27% (95% CI 12–39%) at 40 years. Hip scores rose in the first decade and stayed above preoperative levels in surviving hips. A higher Tönnis osteoarthritis grade before surgery (HR 2.3 per grade) and a positive anterior impingement test (HR 3.9) were associated with conversion. Age above about 28 also separated worse outcomes, though age tracked with joint degeneration.
This is a small single-surgeon case series from the learning curve of the operation, and only 11 hips had full follow-up. Modern technique and selection should do better. The message for selection still holds: the state of the joint before surgery matters most.
- Grade osteoarthritis on preoperative radiographs; each Tönnis grade was associated with higher conversion risk.
- Examine for anterior impingement before offering osteotomy; a positive test was linked to conversion.
- Counsel young patients that osteotomy can delay hip replacement by decades, not always prevent it.
- Weigh joint condition over age alone when selecting patients.
Why it matters
It gives young patients with dysplasia a real long-term number for what joint preservation can achieve.
Don't overread it
A small early-era single-surgeon series — modern outcomes are likely better.
The statistics, in plain English
A 27% survivorship with an interval of 12–39% is imprecise because so few hips remain. The hazard ratios are associations from a small cohort and should not be read as precise risk scores.
Read the rest in the app
You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.
Scan to keep reading on your phone. No account needed to start.
Tomorrow morning, before your first patient
One edition a day for orthopaedics, written by the desk, every claim tied to its paper. Six minutes.
Get the app — free