Initial deformity, age affect revision risk after elbow arthroplasty

Study showed a trend toward higher rates of bushing wear in total elbow replacement patients with post-traumatic arthritis.

Younger patients who undergo total elbow replacement for more severe pre-existing deformities or for post-traumatic conditions have a greater risk for developing excessive wear of the implant's bushings, a retrospective study found.

Brian P. Lee, MD, and colleagues at the Mayo Clinic in Rochester, Minn., reviewed the records for 919 total elbow arthroplasty patients treated at the clinic over a 20 year period. The surgeon implanted a Coonrad-Morrey semiconstrained total elbow prosthesis (Zimmer) in all cases.

Overall, 12 cases required bushing exchange, according to the study.

The researchers noted that these patients had a significantly younger mean age compared to the rest of the patient sample — 44 years vs. 62 years (P<.001). Additionally, they identified a trend toward greater bushing wear among patients with post-traumatic arthritis compared to patients with rheumatoid arthritis.

Among the total study population of 919 patients, surgeons had initially treated 294 patients for post-traumatic arthritis and 377 for rheumatoid arthritis. Of these, seven post-traumatic arthritis patients and five rheumatoid arthritis patients required revision, according to the study.

“It is possible that the feature with the greatest prognostic importance is severe preoperative deformity at the time of the index total elbow arthroplasty,” the authors said.

Nine of the 12 revised patients initially had extensive or high-grade deformities, or had lost at least one humeral condyle before their original arthroplasty procedure. Additionally, three elbows that required a second bushing exchange had “marked” initial deformities and loss of the humeral-ulna relationship, according to the study.

“The insight documented ... is that correcting deformity comes at a higher price of a potential increased rate of bushing wear. Our current practice, therefore, is to extensively release soft tissue contractures to eliminate postoperative deformity. We are more willing to resect bone in order to lessen soft tissue tension that can result in an imbalance that differentially loads the polyethylene,” they said.

Surgeons reported the isolated bushing exchange as technically successful in all revised patients. No cases experienced wound complications or infection, according to the study.

Operating surgeons did find marked synovial discoloration caused by titanium particle debris in four patients. However, the osteolytic process did not appear to compromise implant fixation or function in any of the revised cases, the authors said.

For more information:
Lee BP, Adams RA, Morrey BF. Polyethylene wear after total elbow arthroplasty. J Bone Joint Surg Am. 2005;87-A:1080-1087.