Patellar fracture after replacement of the tibio-femoral joint with the ICLH prosthesis.

Four cases are reported of spontaneous fracture of the patella after ICLH replacement of the knee for Rheumatoid Arthritis. Three of these occur-red in patellae that had not themselves been replaced; one in a resurfaced patella. The former required no specific treatment but the latter required revision surgery. It is argued that the existence of this complication may represent a contra-indication to patellar replacement in the osteoporotic rheumatoid knee.