2015 ISAKOS Biennial Congress ePoster #1452

Opposite Compartment Progression of Osteoarthritis in Lateral UKA: An Outcome and Radiographic Study

Stephanie C. Petterson, MPT, PhD, Old Greenwich, CT UNITED STATES
Sarah Stelma, BS, Stamford, CT UNITED STATES
Kevin D. Plancher, MD, MPH, New York, NY UNITED STATES

Orthopaedic Foundation and Plancher Orthopaedics & Sports Medicine, Greenwich and New York, CT and NY, USA

FDA Status Not Applicable

Summary: Progression in opposite compartments following a lateral UKA does not appear to affect clinical outcomes with patients returning to tennis, skiing and jogging without prosthesis failure.




Lateral compartment osteoarthritis (OA) accounts for 10% of all patients with knee OA, and lateral unicondylar knee arthroplasty (UKA) has become an increasingly favorable surgical option for these patients. While good to excellent clinical outcomes have been demonstrated with lateral UKA, the consequences to the remaining opposite compartments are unknown. The purpose of this study was to assess the progression of OA in the medial and patellofemoral compartments of lateral UKA patients and to assess whether progression correlated with patient-reported functional outcomes.


40 lateral UKA were performed in 36 patients (21 women, 15 men; age 65±12 years), by one surgeon (KDP) from 2004-2012. Minimum of 2 year follow-up was required for inclusion. Radiographic evaluation (Rosenberg, Merchant, AP views) was used to grade OA in the medial and patellofemoral compartments using the Kellgren-Lawrence (KL) scale by 2 raters. Functional outcomes were measured using the WOMAC, IKDC, and Tegner questionnaires. One-way ANOVA was used to assess differences in functional scores between compartment progression groups (e.g. no progression, medial progression only, patellofemoral progression only, medial and patellofemoral progression).


By last follow up (4.9±2.4 years), 12 patients showed no opposite compartment OA progression, 12 patients had medial progression, 7 patients had patellofemoral progression, and 9 patients had medial and patellofemoral progression. There were no significant differences in total WOMAC, IKDC, or Tegner scores between groups (for each p<0.05).


Medial and patellofemoral compartment progression in lateral UKA patients appears to simply be a radiographic phenomenon. While progression may occur in the opposite compartment after a lateral ULA, it does not appear to impact clinical outcomes. Patients can return to sporting activities such as tennis, skiing, and jogging without concern of prosthesis failure.