Jordy van Sambeeck

A detaching, V-shaped tibial tubercle osteotomy is a safe procedure with a low complication-rate 4 65 In three cases the tibial tubercle proximalized without breakage of the screws. It has been recommended that these screws should be at least 2 mm longer than the measured bi-cortical distance to ensure adequate bite [13]. In retrospect this was not the case in two out of three situations. In only one case the piece of bone that was trans positioned fromdistal to proximal became loose. So no additional fixation is necessary for this bone block besides compression between the cortices. The infection rate (0.76%) was with once a septic arthritis and one superficial wound infection comparable to the findings of Payne et al. [6]. The other remarkable finding was the low number of screw removal in this case series. Most studies maintain percentages up to 50% of hardware removal in TTO. Payne found that in the complete tubercle detachment group this risk was 48.3%. One of the reasons why in this study this percentage is only as low as 8.4% is that we use the countersink when placing the screws. Secondly, all patients got instructed that the hardware is only removed in case of specific complaints of the screws. The most important weakness is the retrospective nature of this study, using only available patient charts. Because the highly specialized character of our clinical practice in patellofemoral instability, the chances that complications occurred without our knowledge are small. All patients were followed up until at least 4 months, so wound problems or non-unions would have been detected. It is very unlikely that tibial fractures were treated in another clinic. A distinct advantage of this study is its large sample size and the uniform technique that was used. Conclusion A V-shaped tibial tubercle osteotomy is a (relatively) safe procedure with a low complication rate. The risks on non-union and tibial fractures are particularly low, despite complete detachment of the periosteum and using a step cut osteotomy.