Revista de Medicina Desportiva (English) November 2018 - Page 30

to perform the exercises and to keep physical activity, particularly if there is ligament laxity. 2 When the conservative treatment fails, surgery must be discussed, and it is dependent on the level of func- tional impairment. The aim of the surgery is getting a perfect patellar tracking with the restoration of the anatomy and correction of the pre- disposing factors, like the rotation of a limb or axial mal-alignment. Several surgical techniques have been described. In children with open physis and patellar mal-tracking and predispos- ing factors it must be considered the reconstruction of the medial femoropatelar ligament (MFPL), the release of lateral retinaculum and the correction of the rotational and axial axes of the limb, for example, performing a temporary hemi- epiphisiodesis. 2 However, cadaveric studies have shown that the release of the lateral retinaculum increases patellar instability. 14 The medial, distal and anterior re-positioning of the tibial tuberosity is non-advised procedure in grow- ing children (boys until 16 years and girls until 14 years of age) due to the risk of partial blockage of growing with subsequent genu recurvatum. The alignment of the distal patel- lar ligament (Roux-Goldthwait) is a viable option for children. 2 The reconstruction of the MFPL has become one of the surgical techniques most important for the chronic patellar instability. This ligament runs from the medial femoral epicondyle to the superior- medial border of the patella bone. There are descriptions of technical for reconstruction of the MFPL with hamstrings, with differences related to the opening or closure of the physis. The several surgical technics vary according to the insertion point at the femur and in patients with open physis it is located 5mm below to the distal physis of the femur. This position prevents the proximal migration of the graft during the longitudinal grow of the bone. 11,15,16 A study published by Fabricant et al confirmed the hypothesis of the MFPL reconstruction being associ- ated to a better high of the patella in cases of patellar instability, indicating that MFPL reconstruction 28 november 2018 can be useful to restore especially the dynamic stability, but also the static stability, placing the patel- lar bone more medial and distal in the trochlear groove. After the MFPL reconstruction the patella can’t move superior and laterally in the trochlea, and the slightly more distal orientation of the graft at the point of femur insertion the high of the patella bone decreases, which also causes the medialization of the patella even without other realign- ment procedures. 11 The MFPL reconstruction allows the correction of the patella alta in the absence of the distalization of the tibial tubercle, which can avoid additional unneeded surgi- cal procedures. What remains uncertain is if pre-surgical patella alta predisposes the initial injury or if it came out from the traumatic femoropatelar instability and from the subsequent rupture of the MFPL. The MFPL reconstruction in children with hamstrings has consistently being associated with a radiographic decrease of the patella high which can, subsequently, restore the bone congruence, drawing a patellar sulcus on the trochlear groove on bigger angle of flexion, that would eliminate the need of procedures to make a concomitant digitalization. 11 The former recurrent dislocations of the patella during infanthood leads to changes on the cartilage signal on the MRI on the young adults 17 , and a study showed a better chondral status on the arthroscopy, on aver- age, one year after reconstruction of the MFPL. 7 That been said, in children and adolescents with open physis, the osteotomies to correct the near- articular bone deformities and trochlear dysplasia must be delayed and the procedures should be done in the soft tissues. It is mandatory to reconsider the definitive proce- dures on a second look after growth closure. 2 Conclusion It is fundamental the evaluation of the risk factors associated to instability because the analysis of the anatomic and radiographic risk factors allows the choice of an individualized treatment. The conservative treatment is the pre- ferred strategy of first choice, but in cases of concomitant anatomic predisposition and recurrence, the reconstruction can be considered. In these cases, when there is bone immaturity, the reconstruction of the medial femoropatelar ligament can be enough, associated or not to procedures in the soft tissue, with the aim to have a permanent sta- bilization of the patella, or, at least, to gain time to perform a definitive none procedure. The authors deny any conflict of interests. Correspondence: Catarina Neto Pereira, Serviço de Ortopedia, Hospital Professor Doutor Fernando Fon- seca, Bibliography 1. Vavken P., Wimmer M. 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