Gautier et al.5, in an excellent cadaveric study, describes the anatomy full article of the medial circumflex artery, determining anastomoses, the protection mechanism of the MFCA, in cases of hip dislocation, by the obturator externus, and proposes a modification in the surgical approach of the KL type, at the level of the external hip rotators. This author determines the preservation of the obturator externus tendon and suggests a tenotomy safety zone of the conjoint tendon, located 1.5 cm from the intertrochanteric line, a measurement that is confirmedly safe as shown by the data obtained in this trial. However, in our study we observed that anatomically the obturator externus is located in a deep plane, below the superolateral insertion of the quadratus femoris, and that it determines a repair point at a more superficial level in the KL approach, which may contribute towards the reduction of iatrogenic lesions of the MFCA.

The KL access route may cause damage to the MFCA if the surgeon does not pay attention to its anatomical topography at the level of the conjoint tendon, obliquus externus and quadratus femoris. In the literary description of the KL approach, it is mentioned that if the approach needs to be extended distally, the surgeonshould perform the de-insertion of the quadratus femoris at the trochanteric level, respecting the limit of 1 cm of approach of this musculature.11 However, based on the observations of this study, we noticed that the MFCA in this region can be reached at distances shorter than those currently described.

Accordingly, the authors recommend that in the performance of the KL approach, with the need for distal extension, the surgeon should disconnect the quadratus femoris muscle at the level of its origin in the ischium, taking the appropriate precautions with the sciatic nerve, which is easily identified, since in this region the MFCA is located in a deeper and lower plane, becoming less susceptible to iatrogenic lesions over the course of treatment of acetabular fractures and non-arthroplasty hip surgery. CONCLUSION We should have the superolateral point of insertion of the quadratus femoris (PIQ) as a superficial parameter of safety for preservation of the proximal third of the MFCA. That parameter D of the MFCA in the female sex is higher than in the male sex.

When it is necessary to extend the KL approach distally, invading the quadratus femoris, we should continue in the direction of its origin in the ischium, taking proper precautions with the sciatic nerve, as its de-insertion in the femur can injure the MFCA. Footnotes All the authors declare that there is no potential conflict of interest referring to this article. Study conducted at the Department of Orthopedics and Traumatology of Hospital Regional do Gama. (SOT-HRG) – Gama- (DF).
This study was approved Cilengitide by the Research Ethics Committee of Universidade Federal de S?o Paulo -Escola Paulista de Medicina.