[The role of understanding the media femoral circumflex artery course in total hip replacement].

PURPOSE OF THE STUDY
On the basis of anatomical dissection of the medial femoral circumflex artery (MFCA) in 32 lower extremities and our clinical experience with managing the deep MFCA branch during total hip replacement surgery performed from the anterolateral approach, we sought a reliable treatment of the injured artery, including identification of the site for making the ligature or the way of avoiding damage to the artery during release of the capsule and pelvitrochanteric muscles.


MATERIAL
Anatomical dissection in the MFCA region on both lower extremities was carried out in 16 adult human cadavers. None of the bodies showed any signs of pathological lesions or post-operative, hip joint-related conditions. METHODS In 12 limbs, a gelatin injection was applied directly into the MFCA. In the remaining limbs dissection was performed without injecting the vessel. We studied the MFCA topography in relation to the surrounding structures, particularly where the MFCA runs along the femoral neck before entering the capsule. During dissection, we dislocated the hip in order to create a model situation similar to that during total hip replacement and to find out any possible changes in the course and tension of the artery due to manipulation with the limb during surgery.


RESULTS
Our observations confirmed that if the MFCA is injured, for instance during release of the pelvitrochanteric muscles, further manipulating with the extremity may result in squeezing the extracapsular part of the MFCA deep branch in space between the external obturator muscle and the quadratus femoris muscle. Thus bleeding from the artery is temporarily stopped, but it will reappear due to joint reduction at the end of surgery. In addition, hip external rotation and adduction may push the artery deeper between the muscles mentioned above. To treat such a situation is then very difficult. When the artery is injured, we recommend treatment by ligature. We proceed in the following way:We identify the exact site of bleeding by placing the extremity, before component implantation, in a neutral position. Using a bone hook, we gently put the femur in a lateral position and do external rotation without adduction. At the identified site of bleeding, we compress the artery with a Mikulicz clamp. Subsequently, we move the limb to adduction and external rotation and through ligature we try to intercept the arterial trunk in a position in which it passes between the quadratus femoris muscle and the external obturator muscle. In case we do not succeed to intercept the injured artery, we make a ligature that contains both the muscles and the artery.


CONCLUSIONS
The relevant literature has not provided information on how to treat the MFCA injured during total hip replacement surgery carried out from the anterolateral approach. Our experience has shown that, during release of the capsule and pelvitrochanteric muscles, the deep branch of the MFCA can be damaged. This intra-operative injury of the MFCA may produce serious bleeding difficult to stop. The resultant blood loss may complicate the post-operative outcome. Therefore, a good understanding of the extracapsular course of the deep MFCA branch can reduce the risk of arterial injury and may aid in a correct treatment of the injured vessel and elimination of the associated blood losses. Key words: medial femoral circumflex artery, bleeding, hip arthroplasty.