Jordy van Sambeeck

Chapter 6 86 Abstract Purpose and Hypothesis Trochlea osteotomy is a rarely performed procedure, only indicated in selected cases. Due to its nature, it could potentially lead to cartilage damage and subsequent early osteoarthritis. We previously reported satisfactory short term results of a lateral condyle elevating osteotomy and now report the long term effect on the clinical outcomes, patellar stability and radiological osteoarthritis. Methods 16 patients (19 knees) with patellar instability due to trochlear dysplasia were previously included. An isolated lateral condyle elevating trochlear osteotomy was performed between 1995 and 2002. We re-examined all patients at minimum 12 years follow-up. Three patients were lost to follow up and one patient underwent a patellofemoral arthroplasty three years post-operative due to progressive osteoarthritis. Complete follow-up was therefore available in 12 patients (15 knees). Recurrent instability, VAS-pain, WOMAC, Lysholm and Kujala scores were used as outcome measures. Radiologic osteoarthritis was recorded using the Iwano and the Kellgren-Lawrence classification. A repeated-measures ANOVA was used to test for repeated measures (pre-operative, two years, final follow up) and Spearman’s correlation coefficient for relations between osteoarthritis and functional scores. Results At final follow up, VAS pain showed a non-significant improvement from 53 to 32 and the mean Kujala score was 76. Lysholm (50 to 72, p=0.021) and WOMAC (74 to 91, p=0.021) scores improved from pre-operative to final follow up. There was no significant difference between clinical scores at two years and at final follow- up. Residual patellar instability was reported in 4 out of 15 knees. Three knees showed no patellofemoral osteoarthritis, 8 knees grade 1 and 4 knees grade 2. No correlation between VAS-pain, Lysholm, WOMAC or Kujala score and osteoarthritis could be identified (Spearman’s correlation coefficient, all p-values ≥ 0.365). Conclusions A stand-alone lateral condyle elevating trochleoplasty results in significant improvement of most clinical scores but when performed as a stand-alone procedure leads to a high percentage of residual instability . In contrast to general believe, we did not find that the development of patellofemoral osteoarthritis after 12 year follow-up exceeded the findings from other case series of trochleoplasties. Level of Evidence: Level IV, case series with no comparison group