Archives of Orthopaedic and Trauma Surgery - 2026-03-14 - Journal Article
Revision rate of large head diameter metal-on-metal total hip arthroplasty: long-term results.
Wakabayashi H, Tone S, Naito Y, Sudo A, Hasegawa M
Topics
Key Takeaway
Large-head MoM THA using the Cormet prosthesis yielded a 25% revision rate and 38% pseudotumor prevalence at minimum 10-year follow-up.
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Summary
This study evaluated long-term outcomes of 92 hips implanted with the Cormet large-head MoM acetabular prosthesis, assessing pseudotumor formation, osteolysis, loosening, and revision rates. MRI detected pseudotumors in 38% of hips at a mean of 5.0 years; cup-side osteolysis occurred in 10.8% and loosening in 6.5%. Twenty-three hips (25%) required revision to metal-on-polyethylene at a mean of 6.3 years, with cup failure rates highest in revised patients versus those with pseudotumors alone or no pseudotumors.
Key Limitation
Single-implant, single-center retrospective design with no ion level data (cobalt/chromium) reported, preventing correlation between metal ion burden and pseudotumor formation or revision risk.
Original Abstract
BACKGROUND
To assess the long-term outcomes (minimum 10 years) of total hip arthroplasty (THA) using a large head diameter metal-on-metal (MoM) acetabular prosthesis.
METHODS
In total, 108 primary THAs (98 patients) were performed using a Cormet MoM acetabular prosthesis. Clinical hip function, radiographic evaluation and revision rate were evaluated.
RESULTS
Of the 98 patients, 15 (16 hips) followed up for < 10 years were excluded. Among the remaining 92 hips (83 patients), 35 (38.0%) had pseudotumors (PTs) detected by MRI at an average of 5.0 years after the initial THA. On radiographic evaluation, osteolysis (OL) was noted in 10 hips (10.8%) on the cup side and six hips (6.5%) on the stem side. Loosening was observed in six hips (6.5%) on the cup side, whereas no loosening was noted on the stem side. Twenty-three hips (22 patients) were switched to metal-on-polyethylene articulation between 1.2 and 14.7 years (mean: 6.3 years) postoperatively due to pain, swelling, infection, and/or implant failure. In this analysis, cup failure (OL, loosening, or both) was the highest in patients with revision surgery compared to those with PTs but not revision surgery and those without PTs.
CONCLUSIONS
The prevalence of PTs was 38.0%, and that of revision surgery was 25%. Some cases required revisions even after 10 years following surgery. We advise against its continued use and recommend regular clinical surveillance, such as MRI, to detect adverse reactions to metal debris and periprosthetic joint infection early.