Measurement of patellar thickness in relation to patellar resurfacing

Patellar thickness is an important consideration for resurfacing in total knee arthroplasty. A patella of 25 mm in thickness is not suitable for resurfacing using the currently available total knee systems. A cross sectional study on patellar thickness using plain radiographs was undertaken on 56 patients. It was observed that the average thickness of the bony part of the patella was 20.05 mm (range 17-23 mm). The actual thickness of cartilage varies from 2.0 to 5.5 mm (mean 3.2 mm). Thus the mean thickness of the patella was 23.2 mm (range 20.2-26.2 mm). The majority of our patients (73%) had patellar thickness of 24 mm or less. The patellar thickness had a significant correlation with the patient's height (R=0.5). Since the majority of our patients have thin patella, we are of the opinion that majority of our patients are not suitable for patellar resurfacing.