Microsurgical anatomy of the extra-articular segment of middle genicular artery

Knowledge of the incompletely studied microsurgical anatomy of the extracapsular part of the middle genicular artery (MGA) could imply an educational value and clinical significance because of the possible risk of injury during knee surgery.

Thirty formol-fixed cadaveric lower limbs in full extension were dissected and used for the measurements of MGA parameters. A second group of measurements was performed on distal ends of 30 adult femurs. Two fresh injected cadaveric lower limbs were explored by means of multidetector computed tomographic angiography (MDCTA).

The MGA originated from the popliteal artery (PA), facing the lateral half of the intercondylar fossa in 16 (53.4 %) specimens, together with the superior lateral genicular artery (SLGA) in ten (33.3 %) cases, or from the same point of origin with SLGA and superior medial genicular artery (SMGA) in 4 (13.3 %) cases. The MGA averaged 15.6 mm in length and 1.8 mm in the outer diameter. After its curved direction the MGA entered the posterior capsule. The average distances of the point of MGA entrance into the joint capsule were as follows: to the lateral femoral epicondyle it was 34.88 mm, to the medial femoral epicondyle 46.38 mm, 5.74 mm lateral to the posterior midline, with an average vertical distance to the femoral subcondylar plane of 28.73 mm.

This detailed anatomical examination with measurements of the extracapsular part of a MGA could be of clinical importance and useful in knee surgery for the prevention of vascular injury of MGA and PA, as well as in radiological examination of the knee region.