Journal of Pediatric Orthopaedics - 2026-07-14 - Journal Article
Total Hip Arthroplasty in Patients With Open Triradiate Cartilage: 10-Year Follow-Up of an Expanded Cohort.
Selemon NA, Reuter ZC, Varas-Rodríguez E, Sierra RJ, Trousdale RT, Grigoriou E
Topics
Key Takeaway
THA in skeletally immature patients with open triradiate cartilage yields 92% implant survivorship and mean Harris Hip Score of 92 at mean 10-year follow-up.
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Summary
This study examined radiographic and functional outcomes of THA performed in patients with open triradiate cartilage (modified Oxford bone age scores 1–2) at a single institution from 2000–2024. Primary indications were AVN (67%), secondary arthritis (25%), and neoplasia (8%). At final follow-up, 92% of implants demonstrated stable osseointegration, all patients ambulated independently, mean HHS was 92, and two acetabular components required revision for aseptic loosening.
Key Limitation
Single-institution retrospective design with only 24 hips across a 24-year span limits statistical power to detect risk factors for the two acetabular revisions observed.
Original Abstract
INTRODUCTION
Total hip arthroplasty (THA) in patients with open triradiate cartilage remains controversial, with an open triradiate cartilage considered a challenge for acetabular component fixation. We previously reported excellent 5-year functional outcomes and implant survivorship in a series of patients undergoing THA with open triradiate cartilage. The current study expands this cohort to 10-year radiographic and functional outcomes.
METHODS
Our institutional Total Joint Registry was queried to identify 24 patients who underwent THA with an open triradiate cartilage between the years 2000 and 2024. Skeletal maturity was assessed utilizing the modified Oxford bone age, with only triradiate scores of 1 and 2 included. Demographic, implant, and radiographic data were collected. Functional outcomes were assessed through the Harris Hip score (HHS).
RESULTS
The previously analyzed cohort (11 patients, 12 THAs) had a mean age of 13 years, and a mean follow-up of 10 years (range: 5 to 15). The overall expanded cohort (24 THAs) had a mean age of 14 years, with a mean follow-up of 6 years (range: 1 to 15) and a mean modified Oxford bone age was 22. The most common indications for THA were avascular necrosis ( 67%), secondary arthritis (25%), and neoplasia (8%). Preoperatively, 54% of patients utilized gait aids; at final follow-up, all patients reported independent ambulation with a mean HHS of 92. Radiographically, 92% of implants showed stable osseointegration at the latest follow-up. Two patients required acetabular component revisions for aseptic loosening, one of whom required rerevision for instability.
CONCLUSION
The present study expands on the largest series in the literature of THA in patients with open triradiate cartilage. Our results demonstrate excellent functional outcomes, 92% implant survivorship, and low complication rates at long-term 10-year follow-up. These findings suggest THA is safe and durable in patients with open triradiate cartilage without the need to delay arthroplasty for closure of the triradiate cartilage.
LEVEL OF EVIDENCE
Level III.