Long term follow up of clinical outcome between patellar resurfacing and nonresurfacing in total knee arthroplasty: Chinese experience.

Background The long term outcome of patellar resurfacing in Chinese has not been well described. This study evaluated more than 10-year clinical outcomes and survivorship of patellar resurfacing or nonresurfacing in total knee arthroplasty. Methods From January 1993 to December 2002, 265 patients accepted total knee arthroplasty in Department of Orthopaedic Surgery, Peking Union Medical College Hospital. Among them, 226 patients (246 knees) were successfully followed up, with 176 knees for patellar resurfacing and 70 knees for nonresurfacing. The survivorship of total knee arthroplasty between two groups and the hospital for special surgery knee score (HSS), patellar score, patellar related complication and radiological results were studied at the latest follow-up. Results The HSS knee score increased from 55.9 +/- 12.2 preoperatively to 92.0 +/- 10.9 postoperatively for patellar resurfacing group and from 56.6 +/- 9.9 to 94.2 +/- 11.4 for nonresurfacing group after average 11.4-year follow-up. Patellar score increased from 13.93 +/- 2.42 preoperatively to 28.33 +/- 2.20 for resurfacing group and from 13.55 +/- 2.73 to 27.8 +/- 2.37 for nonresurfacing group. There was no statistically significant difference for both HSS score, patellar score between the two groups with higher rate of anterior knee pain for nonresurfacing group. Patellar nonresurfacing had higher lateral subluxation than resurfacing group according to radiological evaluation. Patients with rheumatoid arthritis had 5.5 fold patellar related complication than patients with osteoarthritis. The 10-year survival rate was not statistically significant different between the two groups (P=0.12). Conclusions There was no significant difference of long-term clinical outcome and survivorship between patellar resurfacing and nonresurfacing. Patellar nonresurfacing can be advisable during primary total knee arthroplasty especially in Chinese patients with osteoarthritis. Selective patellar resurfacing for patients with rheumatoid arthritis can achieve lower patella related complication.