Incidence and factors associated with squeaking in alumina-on-alumina THA.

BACKGROUND: The alumina-on-alumina bearing surface, which has a high wear resistance and a good biocompatibility, is widely used in THA but recently has been associated with squeaking. While various authors have reported factors associated with squeaking, they remain poorly understood.

QUESTIONS/PURPOSES: To contribute to the debate on squeaking we therefore asked the following questions: (1) What is the incidence of squeaking in alumina-on-alumina THA? (2) What factors are associated with squeaking in alumina bearings in our practice?

METHODS: We retrospectively reviewed 168 patients (173 hips) who had primary alumina-on-alumina THAs. The mean age of the patients was 53 years (range, 18 to 81 years). Minimum followup was 5.6 years (average, 7.3 years; range, 5.6-9.4 years). All patients were evaluated clinically and radiographically with attention to periprosthetic osteolysis, squeaking, and ceramic fracture. When the patient reported squeaking, we determined the onset, reproducibility, and activities associated with the squeaking. We recorded patient (gender, age, height, weight, and body mass index) and surgical factors (abduction angle of cup, size and length of ceramic head component, and diameter of cup in the implant).

RESULTS: Eight of the 168 patients (5%) had squeaking hips. Squeaking was more common in males and in those with large ceramic heads. There were no complications or revisions in the squeaking group. One ceramic liner fracture was associated with trochanteric nonunion.

CONCLUSIONS: When recommending alumina-on-alumina bearing surfaces to patients they should be clearly informed of the possibility of squeaking. Patients with risk factors for squeaking should be followed at regular intervals.