Early outcomes of twin-peg mobile-bearing unicompartmental knee arthroplasty compared with primary total knee arthroplasty.
OBJECTIVE
Since redesign of the Oxford phase III mobile-bearing unicompartmental knee arthroplasty (UKA) femoral component to a twin-peg design, there has not been a direct comparison to total knee arthroplasty (TKA). Thus, we explored differences between the two cohorts.


METHODS
A total of 168 patients (201 knees) underwent medial UKA with the Oxford Partial Knee Twin-Peg. These patients were compared with a randomly selected group of 177 patients (189 knees) with primary Vanguard TKA. Patient demographics, Knee Society (KS) scores and range of movement (ROM) were compared between the two cohorts. Additionally, revision, re-operation and manipulation under anaesthesia rates were analysed.


RESULTS
The mean follow-up for UKA and TKA groups was 5.4 and 5.5 years, respectively. Six TKA (3.2%) versus three UKAs (1.5%) were revised which was not significant (p = 0.269). Manipulation was more frequent after TKA (16; 8.5%) versus none in the UKA group (p < 0.001). UKA patients had higher post-operative KS function scores versus TKA patients (78 versus 66, p < 0.001) with a trend toward greater improvement, but there was no difference in ROM and KS clinical improvement (p = 0.382 and 0.420, respectively).


CONCLUSIONS
We found fewer manipulations, and higher functional outcomes for patients treated with medial mobile-bearing UKA compared with TKA. TKA had twice the revision rate as UKA although this did not reach statistical significance with the numbers available. Cite this article: Bone Joint J 2016;98-B(10 Suppl B):28-33.
Doctors Medical Center, 1441 Florida Avenue, Modesto, CA 95350; (209) 576-3528, USA.
Z C
ZC
Lum
Joint Implant Surgeons, Inc., and Department of Orthopaedics, The Ohio State University Wexner Medical Center, and Mount Carmel Health System, 7333 Smith's Mill Road, New Albany, Ohio USA 43054, USA.
A V
AV
Lombardi
Joint Implant Surgeons, Inc., and Mount Carmel Health System, 7333 Smith's Mill Road, New Albany, Ohio USA 43054, USA.
J M
JM
Hurst
Joint Implant Surgeons, Inc., and Mount Carmel Health System, 7333 Smith's Mill Road, New Albany, Ohio USA 43054, USA.
M J
MJ
Morris
Joint Implant Surgeons, Inc., and Mount Carmel Health System, 7333 Smith's Mill Road, New Albany, Ohio USA 43054, USA.
J B
JB
Adams
Joint Implant Surgeons, Inc., and Department of Orthopaedics, The Ohio State University Wexner Medical Center, and Mount Carmel Health System, 7333 Smith's Mill Road, New Albany, Ohio USA 43054, USA.
K R
KR
Berend
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation* / Q000379:methods / Q000534:rehabilitation; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000601:surgery*; D010147:Pain Measurement / Q000379:methods; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016059:Range of Motion, Articular; D012042:Registries; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D016896:Treatment Outcome
Manipulation; Outcomes; Primary total knee arthroplasty; Revision rate; Twin-peg mobile-bearing; Unicompartmental knee arthroplasty
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