Cementless uncoated polyethylene acetabular components in total hip replacement. Review of five- to 10-year results

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Medical Device Research

Background:

• Total hip replacement (THR) is a common procedure for hip osteoarthritis.
• Cementless acetabular components are widely used, but long-term outcomes require evaluation.
• High-density polyethylene (HDPE) is a common bearing material, but concerns exist regarding wear debris.

Purpose of the Study:

• To evaluate the long-term results of cementless, non-coated HDPE acetabular components combined with cemented Müller stems in THR.
• To identify factors associated with component loosening and failure.
• To inform future implant design and surgical recommendations.

Main Methods:

• Retrospective review of 545 consecutive total hip replacements.
• Follow-up at 5-10 years with 421 patients (445 hips) assessed via questionnaire, clinical examination, and radiography.
• Statistical analysis to correlate patient demographics, implant characteristics, and outcomes.

Main Results:

• 86% of reviewed hips had good or excellent results at 5-10 years.
• High rates of radiological loosening of the acetabular component were observed after year six, and clinical loosening after year eight.
• Loosening was more frequent in women, younger patients, and with smaller acetabular sizes. Calcar resorption was linked to acetabular loosening.

Conclusions:

• The observed loosening is likely due to polyethylene debris causing a foreign body reaction and bone erosion.
• Direct bone-polyethylene contact should be avoided in acetabular component design.
• The use of this specific prosthesis has been discontinued due to these findings, advocating for coated components or alternative materials.