Hydroxyapatite coating of an acetabular prosthesis. Effect on stability

Area of Science:

• Orthopedic surgery
• Biomaterials science
• Radiology

Background:

• Total hip replacement (THR) is a common procedure for hip osteoarthritis.
• Acetabular component fixation is crucial for long-term implant survival.
• Hydroxyapatite (HA) coating is used to improve bone integration and implant stability.

Purpose of the Study:

• To evaluate the radiological and clinical outcomes of HA-coated versus uncoated press-fit acetabular components at 2-3 years post-THR.
• To assess the effect of HA coating on component migration, radiolucent lines, and clinical results.

Main Methods:

• Prospective study comparing two groups of patients undergoing primary THR.
• Group 1: 69 patients with HA-coated SLF acetabular components.
• Group 2: 40 patients with uncoated SLF acetabular components.
• Assessment of component stability via proximal migration and angle of inclination measurements.
• Radiographic analysis for radiolucent lines (RLLs).

Main Results:

• No significant difference in clinical outcomes or mean proximal linear wear between groups.
• Fewer radiolucent lines (RLLs) observed in the HA-coated group.
• HA-coated cups showed a trend towards reduced proximal migration (0.06 mm/year vs 0.20 mm/year).
• Significant reduction in rotational migration (0.08°/year vs 0.44°/year, p=0.023) and change in inclination angle in the HA-coated group.

Conclusions:

• Partial HA coating enhances the stability of press-fit acetabular components.
• HA coating reduces radiolucent lines and rotational migration.
• HA coating does not appear to affect clinical outcomes or polyethylene wear rates in the short term.