Fixed bearing lateral unicompartmental knee arthroplasty--short to midterm survivorship and knee scores for 101 prostheses.
BACKGROUND
Isolated unicompartmental knee arthritis is less common laterally than medially. Lateral unicompartmental knee arthroplasty (UKA) constitutes only 1% of all knee arthroplasty performed. Use of medial UKA is supported by several published series showing good long-term survivorship and patient satisfaction, in large patient cohorts. Results of lateral UKA however have been mixed. We present the short and mid-term survivorship and 5-year clinical outcome of 101 lateral UKAs using a single prosthesis.


METHODS
Over a 9 year period, 100 patients who satisfied inclusion criteria underwent a lateral fixed-bearing unicompartmental arthroplasty. American Knee Society (AKSS), Oxford Knee (OKS) and modified Western Ontario McMaster Universities Arthritis Index (WOMAC) scores were completed preoperatively and at 1, 2 and 5 years postoperatively. Kaplan-Meier survival analysis was used to determine the 2-year and 5-year survivorship, using revision for any cause as end point.


RESULTS
Survivorship was 98.7% and 95.5% at 2 and 5 years respectively. 1 knee was revised for subsidence of the tibial component and 1 knee for progression of medial compartment osteoarthritis. Of a possible 35 knees in situ at 5 year follow-up, 33 knees were fully scored. Median AKSS, OKS and modified WOMAC scores were 182, 41, and 16 respectively.


CONCLUSIONS
The mid-term survivorship and outcome scores at 5-years suggest that lateral unicompartmental knee arthroplasty provides a valuable alternative to total joint replacement in selected patients with isolated lateral tibio-femoral arthritis at mid-term follow-up. Level II evidence.
The Bristol Knee Group, Avon Orthopaedic Centre, Southmead Hospital, Bristol BS10 5NB, UK. Electronic address: jrasmith@me.com.
James R A
JR
Smith
The Bristol Knee Group, Avon Orthopaedic Centre, Southmead Hospital, Bristol BS10 5NB, UK.
James R
JR
Robinson
The Bristol Knee Group, Avon Orthopaedic Centre, Southmead Hospital, Bristol BS10 5NB, UK.
Andrew J
AJ
Porteous
The Bristol Knee Group, Avon Orthopaedic Centre, Southmead Hospital, Bristol BS10 5NB, UK.
James R D
JR
Murray
The Bristol Knee Group, Avon Orthopaedic Centre, Southmead Hospital, Bristol BS10 5NB, UK.
Mohammad A
MA
Hassaballa
The Bristol Knee Group, Avon Orthopaedic Centre, Southmead Hospital, Bristol BS10 5NB, UK.
Neil
N
Artz
The Bristol Knee Group, Avon Orthopaedic Centre, Southmead Hospital, Bristol BS10 5NB, UK.
John H
JH
Newman
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D016059:Range of Motion, Articular; D016896:Treatment Outcome
Arthroplasty; Knee; Lateral; Survivorship; Unicompartmental