Hydroxyapatite-coated hip prostheses. Early results from an international study

Area of Science:

• Orthopedic Surgery
• Biomaterials Science
• Biomedical Engineering

Background:

• Total hip arthroplasty (THA) aims to restore function and alleviate pain.
• Hydroxyapatite (HA) coatings enhance bone integration of implants.
• Optimizing stress transfer in the proximal femur is crucial for long-term implant success.

Purpose of the Study:

• To evaluate the clinical and radiographic outcomes of a novel hydroxyapatite-coated hip prosthesis.
• To assess the implant's ability to promote proximal femoral stress transfer.
• To investigate bone remodeling and implant integration over a 2-year follow-up period.

Main Methods:

• A prospective study involving 222 patients undergoing primary THA.
• Utilized a roughened titanium alloy femoral component with proximal HA coating.
• Employed a proximal press-fit technique with distal femoral over-reaming.
• Clinical assessment using Merle D'Aubigné scores and radiographic evaluation.

Main Results:

• Excellent clinical outcomes with high Merle D'Aubigné scores at 6 months and 2 years.
• Complete acetabular and proximal femoral osseointegration without loosening.
• Observed bone densification at the coated-uncoated transition zone (54%) and distal reactive lines (52%).
• Minimal thigh pain (3.6%) reported at 2 years.

Conclusions:

• The hydroxyapatite-coated hip prosthesis demonstrates excellent clinical performance and radiographic evidence of osseointegration.
• The implant design effectively facilitates proximal femoral stress transfer, potentially improving long-term implant survival.
• Further research may explore long-term bone adaptation and the implications of observed distal reactive lines.