In recent years tribological development of knee replacement impants has beeen introduced with several benefits. However, concomitant problems were noticed following widespread use.

High-flexion total knee replacement (PFC RPF DePuy) has been developed with a view to improve flexion and the design is expected to have a better patello-femoral biomechanics. However, high secondary patella resurfacing rate has been noticed in the current series.

We have retrospectively reviewed 119 knees in 96 patients who underwent RPF knee replacement with selective patellar resurfacing from 2006 to 2010 by the senior author. 71 were performed without primary resurfacing while 48 in knees patella was resurfaced primarily due to significant symptomatic arthritic changes. Majority were females (57 versus 39 males). Average follow-up period was 37 (12-62) months.

Twelve (16.9%) knees were subjected to secondary resurfacing due to continuing anterior knee pain. Average time from primary total knee replacement to secondary resurfacing was 18 months (8-35). Most of the patients were satisfied following the secondary resurfacing.

Mean Oxford Knee Score in the group where the patella was resurfaced primarily was 33.1 (9-48), in the group where the patella was not resurfaced 32.8 (11-47), in the secondary resurfacing group 31.8 (14-43) and in the revision group 20.5 (16-25).

RPF knee replacements in our series have a considerably higher rate of secondary patellar resurfacing as compared with published literature. We recommend primary patellar resurfacing of all RPF knee replacements to avoid this problem. Further analysis of the prosthetic design would be beneficial in relation to clinical outcome.

No of patients-96

Total no of knee-118

Av age-66.5

Females-57

Males-39

Patella not resurfaced- 73

Resurfaced-45

Revised-10(13.7%)

Revision to TKR (TC3) for different reason-3(2.54%)

Average time from primary to secondary resurfacing-