Pseudotumor formation and serum ions after large head metal-on-metal stemmed total hip replacement. Risk factors, time course and revisions in 706 hips.
Arch Orthop Trauma Surg
; 135(3): 417-25, 2015 Mar.
Article
in En
| MEDLINE
| ID: mdl-25663048
ABSTRACT
INTRODUCTION:
The incidence and natural course of pseudotumors in metal-on-metal total hip arthroplasties is largely unknown. The objective of this study was to identify the true incidence and risk factors of pseudotumor formation in large head metal-on-metal total hip arthroplasties. MATERIALS ANDMETHODS:
Incidence, time course and risk factors for pseudotumor formation were analysed after large femoral head MoM-THA. We defined a pseudotumor as a (semi-)solid or cystic peri-prosthetic soft-tissue mass with a diameter ≥2 cm that could not be attributed to infection, malignancy, bursa or scar tissue. All patients treated in our clinic with MoM-THA's were contacted. CT scan, metal ions and X-rays were obtained. Symptoms were recorded.RESULTS:
After median follow-up of 3 years, 706 hips were screened in 626 patients. There were 228 pseudotumors (32.3 %) in 219 patients (35.0 %). Pseudotumor formation significantly increased after prolonged follow-up. Seventy-six hips (10.8 %) were revised in 73 patients (11.7 %), independent risk factors were identified. Best cutoff point for cobalt and chromium was 4 µg/l (68 and 77 nmol/l).CONCLUSIONS:
This study confirms a high incidence of pseudotumors, dramatically increasing after prolonged follow-up. Risk factors for pseudotumors are of limited importance. Pain was the strongest predictor for pseudotumor presence; cobalt chromium and swelling were considered poor predictors. Cross-sectional imaging is the main screening tool during follow-up.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Arthroplasty, Replacement, Hip
/
Metal-on-Metal Joint Prostheses
/
Granuloma, Plasma Cell
/
Hip Prosthesis
Type of study:
Etiology_studies
/
Incidence_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Language:
En
Journal:
Arch Orthop Trauma Surg
Year:
2015
Document type:
Article