To report patella thickness measurements in Korean.

Between July 1990 and December 2000, the thicknesses of the patella in 1,245 patients who underwent total knee replacement arthroplasty (TKRA) were measured in 0.5 mm increment using caliper during operation. The diagnoses of the 833 knees were degenerative osteoarthritis and 386 knees rheumatoid arthritis. The difference of the thicknesses of the patellas in the same individuals were evaluated in cases of bilateral TKRAs. The relationships between the patellar thickness and sex, body weight and height were evaluated.

The average thickness of the patella was 21.46±1.59 (18-32) mm. The thickness of the patella was increased significantly in the male (p<0.001), with height (p<0.001) and with weight (p<0.001). There was a significant difference in the thickness of the patellas in same individual (p<0.001), but no significant difference in its thickness between osteoarthritis and rheumatoid arthritis (p>0.05).

Because the thickness of the patella in Korean adult was less than that in the Caucasian, the thickness of the patella after resurfacing the patella during TKRA may be reduced unnecessarily, which may cause increased strain on the surface of the patella. This increased strain may result in the fracture of the patella consequently. In the present study, the thickness of the patella after resurfacing during TKRA was 13.9±0.7 mm. Considering the fact that the prevalence of patella fracture was low (0.24%) in our study, the author's method of patella resurfacing is believed to be appropriate in Koreans.