Hydroxyapatite-coated RM cup in primary hip arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Medical Device Engineering

Background:

• Total hip arthroplasty (THA) is a common procedure for hip osteoarthritis.
• The long-term success of THA depends on the durability of acetabular components.
• Hydroxyapatite coating aims to improve bone integration and implant longevity.

Purpose of the Study:

• To evaluate the long-term clinical and radiological outcomes of hydroxyapatite-coated Robert Mathys (RM) acetabular cups in primary THA.
• To determine the survival rate and identify potential failure modes of this specific implant design.

Main Methods:

• Retrospective review of 113 patients (127 hips) who underwent primary THA with RM cups.
• Mean follow-up of 9.4 years.
• Analysis of radiological findings (radiolucency, migration) and clinical outcomes, including revisions.

Main Results:

• A 10-year survival rate of 97.9% was predicted using the life table method.
• Only three acetabular components required revision (two for loosening, one for erosion).
• No cases of cup migration or dislocation were observed; no radiolucency was noted in the remaining cups.

Conclusions:

• Hydroxyapatite-coated RM acetabular cups demonstrate excellent long-term survivorship and a low revision rate in primary THA.
• The implant design appears to promote stable fixation and minimize adverse radiological findings.
• These findings support the use of this implant in total hip replacement procedures.