Failure mechanisms in uncemented Kudo type 5 elbow prosthesis in patients with rheumatoid arthritis: 7 of 49 ulnar components revised because of loosening after 2-10 years.
BACKGROUND
Both components of the Kudo type 5 elbow prosthesis can be inserted with or without the use of cement. There have been no reports on the use of this prosthesis with all components uncemented in patients with rheumatoid arthritis.


METHODS
We reviewed 49 primary uncemented Kudo type 5 elbow prostheses, inserted in 36 patients with rheumatoid arthritis, after mean 6 (2-10) years. Patients were assessed clinically both pre- and postoperatively (pain, instability, motion, ulnar neuropathy) and radiographically. Furthermore, at the time of follow-up clinical outcome was assessed using the Elbow Function Assessment Scale.


RESULTS
At review, 7 of 49 elbows had undergone revision because of symptomatic loosening of the ulnar component. In 42 unrevised elbows, clinical outcome was excellent in 29, good in 7, fair in 5, and poor in one. 31 of 42 elbows had no pain; 11 were painful at rest (VAS 1-2) and/or as a result of activity (VAS 1-8). With revision as endpoint, survival was 86% at 6 years. Intraoperative malpositioning of the ulnar component with a valgus or varus alignment of < 5 degrees was associated with worse survival.


CONCLUSIONS
We found an unexpectedly high rate of loosening of the ulnar component, which was associated with intraoperative malpositioning of the prosthesis. The ulnar component of this prosthesis should not be inserted without cement in patients with rheumatoid arthritis.
Brinkman
Justus-Martijn
JM
Department of Orthopedics, Sint Maartenskliniek. Nijmegen, The Netherlands.
de Vos
Maarten J
MJ
Eygendaal
Denise
D
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging / Q000601:surgery*; D019643:Arthroplasty, Replacement / Q000009:adverse effects* / Q000379:methods; D002484:Cementation; D004551:Elbow Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology; D007595:Joint Prosthesis / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation; D014457:Ulna / Q000000981:diagnostic imaging / Q000601:surgery*