Jordy van Sambeeck

Summary, general discussion and future perspectives 9 151 recurrent dislocation was 16 years, the average age of the cohort was 19.8 years. It should be mentioned that the absolute number (13 dislocations) is small and the difference in mean age is not statistically significant. A contributing factor for this rate of dislocation is the absence of anadditional MPFL- reconstruction, this was only performed in 5.6% of patients. A methodological limitation of this study is the heterogeneity of the study population. One should be aware of this when interpreting these results and translating these to daily practice. In Chapter 6 we established the long-term results of the lateral facet elevating trochlear osteotomy. We re-evaluated a cohort of 17 patients to describe the clinical and radiological results over time of this technique in patients at aminimum of twelve years after surgery. Follow-up of this cohort could be obtained in 12 patients and 15 knees with a mean follow-up of 14.3 years. Mean age at follow- up was 36.5 years. Late complications, subsequent surgery, number of recurrent dislocations, VAS pain, Lysholm, WOMAC and Kujala Knee scores were obtained. Physical examination was performed and conventional radiographs were taken. Patient reported outcome scores showed no significant deterioration from 2 years to final follow-up. Four patients reported a recurrent patellar dislocation. We observed an increase in radiological osteoarthritis in all three compartments of the knee (medial tibiofemoral, lateral tibiofemoral, patellofemoral) when compared to pre-operative values, but this increase was limited to the lower grades on Kellgren Lawrence 6 and Iwano scale 7 . Chapter 5 and Chapter 6 both present outcomes after a lateral facet elevating trochlear osteotomy. The indication for this type of trochlear osteotomy has narrowed in recent years and consequently the procedure is performed less often. Therefore, it might be even more important to have data on previous outcome of this procedure. The results of the study presented in chapter 6 do not confirm the concern for early patellofemoral osteoarthritis (PF OA) after this procedure that exists among many physicians. In both studies an additional MPFL- reconstruction was rarely performed, which might have led to a relatively high rate of redislocation. Strict indication for this type of trochlear osteotomy is key to a satisfactory result. Patients with recurrent patellar dislocation with a prominent J-sign at physical examination (indicating clinically relevant maltracking at early flexion) and underlying trochlear dysplasia without a proximal bump but with a convex or short proximal trochlea can be a good candidate for a lateral facet elevating trochlear osteotomy. A medial patellofemoral ligament (MPFL) reconstruction should always be performed as additional procedure to decrease the risk of recurrent dislocation. With these considerations in mind, a lateral-facet elevating trochlear osteotomy is a safe procedure with a satisfactory result.