2019 ISAKOS Biennial Congress ePoster #952
Failure Rates of Lateral UKA and Return to Sports without Restrictions including Skiing: Average 10-Year Follow-Up
Kevin D. Plancher, MD, MPH, New York, NY UNITED STATES
Jeffrey Alwine, DO, Cos Cob, CT UNITED STATES
Merja Perhonen, MD, PhD, Stamford, CT UNITED STATES
Stephanie C. Petterson, MPT, PhD, Old Greenwich, CT UNITED STATES
Orthopaedic Foundation, Stamford, CT, UNITED STATES
FDA Status Cleared
Patients with 15-year follow up of lateral UKA patients showed significantly improved functional outcomes, knee range of motion and excellent implant survivorship despite sporting activities, thus, lateral UKA with isolated lateral compartment osteoarthritis allows patients to return to moderate and vigorous sports.
Isolated lateral compartment osteoarthritis accounts for 10% of arthritic knees. While some suggest total knee arthroplasty reliably eliminates pain and improves function with good to excellent implant survivorship, lateral unicondylar knee arthroplasty (UKA) for isolated lateral compartment osteoarthritis has become a favorable option with improved implant design and surgical technique. We investigated clinical and functional outcomes after lateral UKA and the determined influence of sporting activities on outcomes and survivorship.
A total of 61 lateral UKAs using lateral parapatellar method were performed in 57 patients by a single surgeon (2003-2017). A minimum of 2-year follow-up was required for inclusion. Clinical examination included measurement of knee flexion and extension range of motion and radiographic evaluation including anterioposterior and 3-foot standing alignment films. Subjective functional outcomes were assessed using Lysholm and International Knee Documentation Committee (IKDC) Scores. Return to sport was evaluated with Tegner Activity score. Sports were categorized as vigorous (e.g. tennis, skiing, hockey) or moderate (e.g. golf, swimming, cycling) based on ACSM guidelines. Failure was defined as conversion to TKA. ANOVA was used to assess differences in outcome measures between groups (p<0.05).
Participants in vigorous sport group (age 59±11 years, BMI 27.2±4.2) were younger than in the moderate sports group (age 67±10 years, BMI 27.8±4.9) (p=0.0048) but not the no sport group (age 64±15, BMI 27.1±5.8). Follow up was 10.0±3.4 years for the vigorous group, 8.0±3.9 years for the moderate group and 10.7±2.9 years for the no sport group and there were no significant differences between the groups. Postoperative mean flexion was 130±7° for the vigorous group, 130±12° for the moderate group and 130±7° for the no sport group (p>0.05).
Postoperative Lysholm Score was 88.8±17.5 for the vigorous group, 86.8±17.7 for the moderate group, and 86.0±7.6 for the no sport group (p=0.4701). Postoperative IKDC Score was 72.1±24.3 for the vigorous group, 73.4±15.4 for the moderate group, and 76.4±9.6 for the no sport group (p=0.2095). Postoperative Tegner score was 5-8 in the vigorous group, 2-4 in the moderate group and 1-2 in the no sport group. There was one failure in the vigorous group (1/18 knees, 5.5%) and one in the moderate group (1/28 knees, 3.5%), which were revised to total knee arthroplasty within 6 years. There were no failures in no sport group (0/14).
Lateral UKA using a lateral parapatellar incision for patients with isolated lateral compartment osteoarthritis allows patients to return to moderate and vigorous sports including tennis, skiing, and hockey without negative consequences and does not negatively impact implant survivorship up to maximal 15 years.