Reintervention after mobile-bearing Oxford unicompartmental knee arthroplasty.
BACKGROUND
Medial compartment osteoarthritis is a common disorder that often is treated by unicompartmental knee arthroplasty (UKA). Although the Oxford 3 prosthesis is commonly used based on revision rate and cumulative survival, our experience suggests that although there may be adequate implant survival rates, we observed a worrisome and undisclosed reintervention rate of nonrevision procedures.


OBJECTIVE
We describe the frequency and cause of repeat intervention subsequent to implanting this device.


METHODS
Between 1998 and 2005, 398 patients underwent UKA using the Oxford 3 prosthesis. The minimum followup was 12 months (mean, 43 months; range, 12-102 months).


RESULTS
Forty of the 398 (10%) patients had 55 (13.8%) repeat anesthetics (reintervention). There were 38 nonrevision reinterventions. Revision was performed in 15 patients (3.8%), but two patients had a second revision (17 revisions or 4.3%). We revised the UKA to a second UKA in seven of the 15 cases but two subsequently were rerevised to a TKA; eight were revised directly to a TKA.


CONCLUSIONS
Although our data confirm the reported revision rates for this prosthesis, we observed a substantial reintervention rate. Most of the reinterventions are minor and are diagnosed frequently and treated arthroscopically. If revision is required, a second UKA may be considered and performed successfully in patients with isolated loosening of one component.


METHODS
Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.
Clark
Marcia
M
Wakefield Orthopaedic Clinic, St Adelaide, 270 Wakefield Street, Adelaide, 5000, Australia.
Campbell
David G
DG
Kiss
Greg
G
Dobson
Peter J
PJ
Lewis
Peter L
PL
D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000295:instrumentation*; D005260:Female; D006801:Humans; D007717:Knee / Q000503:physiopathology / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000601:surgery*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome