Wear particles and osteolysis in patients with total wrist arthroplasty.

PURPOSE: To determine whether the amount of polyethylene debris in the interphase tissue between prosthesis and bone in patients with total wrist arthroplasty correlated with the degree of periprosthetic osteolysis (PPO); and to investigate the occurrence of metal particles in the periprosthetic tissue, the level of chrome and cobalt ions in the blood, and the possible role of infectious or rheumatoid activity in the development of PPO.

METHODS

Biopsies were taken from the implant-bone interphase in 13 consecutive patients with total wrist arthroplasty and with at least 3 years' follow-up. Serial annual radiographs were performed prospectively for the evaluation of PPO. We collected blood samples for white blood cell count, C-reactive protein, and metallic ion level.

RESULTS

A radiolucent zone of greater than 2 mm was observed juxta-articular to the radial component in 4 patients and at the carpal component in 3. The magnitude of the radiolucent zone tended to level out over time. We observed subsidence of the implant in 3 patients on the carpal side and in none on the radial side. The amount of polyethylene and metallic debris was generally small and did not correlate with the width of the radiolucent zone. The blood levels of chrome and cobalt ions were normal. There was no evidence of infectious or rheumatoid activity.

CONCLUSIONS

Polyethylene wear has been accepted as a major cause of osteolysis in total hip arthroplasty, and metallic debris has also been cited to be an underlying cause. However, our hypothesis that polyethylene debris correlated with the degree of PPO could not be confirmed. Also, metallic debris and infectious or rheumatoid activity did not correlate with PPO.

TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic I.