Related Experiment Video
Updated: May 23, 2026
07:43
In Vivo Quantification of Hip Arthrokinematics during Dynamic Weight-bearing Activities using Dual Fluoroscopy
Published on: July 2, 2021
Do joint registries report true rates of hip dislocation?
Peter A Devane1, Philip J Wraighte, David C G Ong
1Department of Orthopaedic Surgery, Wellington Regional Hospital, Riddiford Street, Newtown, Wellington 6021, New Zealand. peterdevane@yahoo.co.nz
Clinical Orthopaedics and Related Research
|March 28, 2012
Summary
The true dislocation rate after primary total hip arthroplasty (THA) is higher than reported by the National Joint Registry (NJR). All dislocations, including closed reductions, must be documented for accurate THA outcome comparisons.
Area of Science:
- Orthopedic surgery
- Arthroplasty research
- Complication surveillance
Background:
- Total hip arthroplasty (THA) dislocation remains a significant complication.
- The New Zealand National Joint Registry (NJR) underreports dislocations, as only revisions are recorded.
- Closed reductions are not captured in current NJR data.
Purpose of the Study:
- To compare the actual dislocation rate for primary THA in Wellington with NJR-reported rates.
- To highlight the discrepancy in recorded versus true dislocation incidence.
- To advocate for comprehensive dislocation data in joint registries.
Main Methods:
- Retrospective review of 570 primary THA patients in the Wellington region (2008-2009).
- Minimum 2-year follow-up.
- Comparison of hospital database records with NZ NJR data.
Main Results:
- The NJR-reported dislocation rate (revision-based) was 1.05%.
- The hospital database identified an additional 8 dislocations treated with closed reduction.
- The true dislocation rate, including closed reductions, was 2.46%.
Conclusions:
- A significant underestimation of primary THA dislocation rates exists in the NZ NJR.
- Comprehensive documentation of all dislocations is crucial for accurate outcome assessment.
- Improved NJR data collection will facilitate better inter-center comparisons and research.
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