Measurement of patellar thickness and surgical techniques of patella resurfacing during total knee arthroplasty in Chinese patients with rheumatoid arthritis / 中国矫形外科杂志

ABSTRACT

[Objective] To measure the patella thickness and to investigate the techniques and safety of patella resurfacing during total knee arthroplasty in Chinese patients with rheumatoid arthritis.[Methods]From Jan.2005 to Jan.2006,the maximal and minimum thickness of the patella,the preserved thickness of bony patella after resurfacing and the total thickness of patella composite after patella replacement in 95 consecutive total knee arthroplasty for rheumatoid arthritis were measured.The patients were followed-up after operation,anterior knee pain and patella fracture were recorded.[Results]1)The mean maximal thickness before resurfacing was(22.01?1.64)mm(range,18~26 mm),the mean minimum thickness before resurfacing was(11.69?2.33)mm(range,6~16mm).2)The mean thickness of preserved bony patellar thickness was(13.23?0.96)mm,(range,11~16 mm),including 11 mm in 4 knees(4.2%),12 mm in 15 knees(12.7%),13 mm in 38 knees(40%),14 mm in 32 knees(33.7%),15 mm in 5 knees(5.3%)and 16 mm in 1 knee(1.1%).The mean thickness of the patella composite was 21.42 mm(range,20~25 mm),the thickness of resurfaced patella was equal to or thinner than the preoperative patellar thickness in 86 knees(90.5%).Anterior knee pain was found in 3 knees,but no patellar fracture or component loosening occurred.[Conclusion]1)The patellar thickness in rheumatoid arthritis is thinner than the thickness in normal patella.2)It is a safe option to retain bony patella thickness at 12~14 mm during patellar resurfacing in Chinese adults with rheumatoid arthritis.3)Patellar resurfacing in patients with rheumatoid arthritis has a good result in a short term.Careful attention to good surgical technique in component alignment and patellar resurfacing is crucial to obtain good results.