Jordy van Sambeeck

Trochleoplasty procedures show complication rates similar to other patellar stabilizing procedures 7 107 Trochleoplasty procedures were performed on 822 knees in 739 patients. Average age of the patients was 22.6 years (range 12 – 53 years). Sixty-seven percent of patients were female. Mean follow-up was 57 months, mean follow-up in individual studies ranged from 12 months to 183 months (16 studies reported mean, 2 medians, 1 range and 1 a minimum of 1 year). Indications for trochleoplasty were recurrent patellar instability, defined as at least 2 patellar dislocations (in 1 study based on 1 documented patellar dislocation 13 ), with underlying trochlear dysplasia. Ten studies 2, 13-21 reported trochlear dysplasia defined according to the Dejour classification of trochlear dysplasia 22 on conventional X-rays or MRI. In two studies, an elevated trochlear boss height on X-ray was additionally required as indication 13, 20 . For some studies indication was also based on presence of the apprehension sign or lateral patellar glide test 2, 14, 15, 17, 21, 23 . All studies reported that additional procedures were performed, except the one of Bereiter 8 that did not report on additional procedures. On average 46% of patients had undergone previous procedures before trochleoplasty including modified Fulkerson-Elmsie Trillat osteotomy, diagnostic arthroscopy, arthroscopic/open lateral release, tibial tubercle transfer, VMO-plasty, Roux-Goldthwaite procedure and chondroplasty. A total of 190 complications occurred in 822 knees, including recurrence of instability (subluxation and dislocation), loss of knee range of motion, development or progression of PF OA, return to OR and miscellaneous surgical complications, such as wound complications. A lateral facet elevating trochlear osteotomy was reported by 2 studies 24, 25 . A deepening trochleoplasty was reported by 17 studies: ten reported on a (modified) Bereiter trochleoplasty 8, 14, 17, 21, 23, 26-30 , five on a (modified) Dejour trochleoplasty 2, 13, 16, 18, 31 , one on an arthroscopic technique 15 , and one on a ‘modified’ technique 20 . A recession wedge trochleoplasty was reported by one study 19 . Complications and miscellaneous results of techniques included in the meta-analysis Meta-analysis could be performed for the complications recurrence of patellar instability (subluxations), recurrent dislocation, PF OA, and further surgery needed for the Dejour and Bereiter trochleoplasty techniques only. Meta-analysis for loss of ROM could only be performed for the Bereiter trochleoplasty. Figures 2-5 show the results of the meta-analyses, including proportion of patients with recurrent dislocation (Figure 2), recurrent instability (Figure 3), PF OA (Figure 4) and need for further surgery (Figure 5). The indications for further surgery were not included in the meta-analysis. For the Bereiter trochleoplasty these were medial subluxation in one patient, reduced ROM in six patients, persistent pain in three patients and recurrence of instability in three patients. For the Dejour trochleoplasty these