Ninety knees were treated in the same centre between1995 and 1999 each had Low Contact Stress (LCS) knee prosthesis with patelloplasty; none of the patients had resurfacing of the patella. The average follow-up period was seven years (ranging from five to nine years). There were no exclusion criteria, almost all the patients included in this study were available for follow-up, the mean age was 75 years, and the majority of the patients were affected by osteoarthritis. All the operations were done by the same surgeon or under his supervision according to the protocol.

Evaluation was performed with using The Knee Society Clinical Rating System and new Patellar Scoring System. The final scoring was done by an independent Senior Physiotherapist. The Knee Society’s radiological evaluation system was used to assess the pre and post-operative alignment of the knee and the prosthesis. Image Tool (IT accessories UTHSCSA) software used to for measurements of patellar tracking and alignments on the digitalised radiographs.

Pre-operatively, the mean Knee Society score on a scale ranging from 0-200 points was 81.50 points (range 25 to 124 points); postoperatively this score improved to a mean of 150.76 points (range 46 to 195 points). Statistical analysis using paired-comparison t-tests showed the score differences were statistically significant at p-values < 0.0001.

None of the patients required resurfacing during the follow-up. There were no reported cases of significant anterior knee pain, dislocation, maltracking or fractured patella.