Alumina-on-HXLPE THA bearings show good long-term wear results

Alumina-on-HXLPE bearings and alumina-on-alumina bearings in cementless THA were compared.

Issue: July 2014

Researchers performed cementless total hip arthroplasty with two types of bearing and compared the wear performance at a mean follow-up of about 12 years for alumina-on-highly-crosslinked polyethylene bearings and alumina-on-alumina ceramic bearings used in 100 patients.

“Under the condition and duration of this study and in this specific group of young and active [patients], contemporary alumina-on-highly crosslinked polyethylene bearings had excellent clinical and radiographical outcomes with no osteolysis. Longer follow-up is needed to evaluate how this procedure performs over a longer duration,” Young-Hoo Kim, MD, of Seoul, said at the American Academy of Orthopaedic Surgeons Annual Meeting.

One treatment on each hip

Kim and colleagues compared the results in 100 patients (200 hips) who underwent bilateral simultaneous sequential cementless total hip arthroplasty (THA) with an alumina-on-alumina ceramic bearing in one hip and an alumina-on-highly-crosslinked polyethylene bearing in the other hip. They compared the clinical and radiographic results, as well as the osteolysis prevalence in these young and active patients, he said.

Young-Hoo Kim

The mean follow-up for the comparison was 12.4 years (with a range of 11 years to 13 years). The patients had a mean age of 45.3 years at surgery. Kim and colleagues included 66 men and 34 women in the study.

Clinical and radiographic follow-up assessments were done at 3 months, 1 year and annually thereafter, Kim said.

“At clinical follow-up, including Harris Hip Score, WOMAC and UCLA activity score, and radiographic follow-up confirmed our findings,” he said.

The Harris Hip Score, WOMAC score and UCLA activity score did not show significant differences between the hips treated with the two types of bearings preoperatively, nor were there significant differences in these outcome measures at the time of final follow-up. Radiographic findings were also not significantly different between the two groups of bearing, according to Kim.

“No hips in either group displayed osteolysis. The Kaplan-Meier survivorship with revision as the end point at 12.4 years was 100% (95% confidence interval [CI], 94% to 100%) for the femoral component in both groups and 99% (95% confidence interval [CI], 93% to 100%) for the acetabular component,” Kim and colleagues wrote in the abstract.

Future of treatment

However, in a few of the hips that received the alumina-on-alumina THA prosthesis, Kim said the patients experienced a squeaking noise during weight-bearing at the 3-year follow up.

“Because the results of using an alumina-on-alumina ceramic and alumina-on-highly-crosslinked polyethylene bearings were similar at 12.4 years follow up, alumina-on-highly-crosslinked polyethylene bearing could replace alumina-on-alumina ceramic to avoid potential squeaking or clicking sound and cup liner fracture,” Kim and colleagues wrote. – by Robert Linnehan

Reference:

Kim YH. Paper #243. Presented at: American Academy of Orthopaedic Surgeons Annual Meeting; March 11-15, 2014; New Orleans.

For more information:

Young-Hoo Kim, MD, can be reached at Ewha Womans University, Mokdong Hospital, The Joint Replacement Center of Korea #911-1, Mokdong, Yangchun-Ku, Seoul 158-710, Republic of Korea; email: younghookim@ewha.ac.kr.
Disclosure: Kim receives royalties from DePuy Synthes.