Systematic review of medial versus lateral survivorship in unicompartmental knee arthroplasty.
BACKGROUND
Unicompartmental knee arthroplasty (UKA) has gained popularity in patients with isolated unicompartmental osteoarthritis. To our knowledge no systematic review has assessed and compared survivorship of medial and lateral UKA. We performed a systematic review assessing medial and lateral UKA survivorship and comparing survivorship in cohort studies and registry-based studies.


METHODS
A search was performed using PubMed, Embase and Cochrane systems. Ninety-six eligible studies reported survivorship, of which fifty-eight reported medial and sixteen reported lateral UKA survivorship. Nineteen cohort studies and seven registry-based studies reported combined medial and lateral survivorship.


RESULTS
The five-year, ten-year and fifteen-year medial UKA survivorship was 93.9%, 91.7% and 88.9%, respectively. Lateral UKA survivorship was 93.2%, 91.4% and 89.4% at five-year, ten-year and fifteen-year, respectively. No statistical difference between both compartments was found. At twenty years and twenty-five years survivorship of medial UKA was 84.7% and 80%, respectively, but no studies reported lateral UKA survivorship at these follow-up intervals. Survivorship of cohort studies was not significantly higher compared to registry-based studies at five years (94.3 vs. 91.7, respectively, p=0.133) but was significantly higher at ten years (90.5 vs. 84.1, p=0.015).


CONCLUSIONS
This is the first systematic review that shows no difference in the five-, ten- and fifteen-year survivorship of medial and lateral UKA. We found a lower survivorship in the registry-based studies compared to cohort studies.
Sports Medicine and Shoulder Service, Department of Orthopaedic Surgery, Hospital for Special Surgery, Weill Medical College of Cornell University, 535 E. 70th Street, New York, NY 10021, United States. Electronic address: jpjvanderlistmd@gmail.com.
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JP
van der List
Sports Medicine and Shoulder Service, Department of Orthopaedic Surgery, Hospital for Special Surgery, Weill Medical College of Cornell University, 535 E. 70th Street, New York, NY 10021, United States. Electronic address: lucas.s.mdonald@gmail.com.
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LS
McDonald
Sports Medicine and Shoulder Service, Department of Orthopaedic Surgery, Hospital for Special Surgery, Weill Medical College of Cornell University, 535 E. 70th Street, New York, NY 10021, United States. Electronic address: pearlea@hss.edu.
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Pearle
D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery*; D007720:Knee Prosthesis; D020370:Osteoarthritis, Knee / Q000601:surgery*; D011474:Prosthesis Design; D016059:Range of Motion, Articular; D012042:Registries; D013997:Time Factors; D016896:Treatment Outcome
Failure rate; Knee arthroplasty; Revision; Survivorship; Unicompartmental knee arthroplasty