PATTERNS OF KNEE ARTHROSIS AND PATELLAR SUBLUXATION

This study was based on the unexpected observation of lateral patellof emoral subluxation in the varus osteoarthritic knee. Standardized radi ographs of 109 knees (65 patients with osteoarthritis) were selected r andomly from the authors' database and retrospectively reviewed. Hip-k nee-ankle alignment data were correlated with patellofemoral subluxati on and tilt, as well as with radiographic patellofemoral grades for ar throsis. The amount and site of patellofemoral arthrosis were correlat ed with patellar position and limb alignment. Patellae that were locat ed centrally in the trochlear groove had the lowest radiographic score for arthrosis. Subluxation of the patella, either medially or lateral ly, was correlated with increased radiographic scores. Limb alignment was not correlated with the radiographic score. A significant percenta ge of varus knees (28%) had unexpected lateral subluxation of the pate lla. This observation has not been reported previously. It may have an impact on surgical decision-making for total knee arthroplasty and os teotomy.