Periosteal Angiosome of the Descending Geniculate Artery

PERIOSTEAL ANGIOSOME OF THE DESCENDING GENICULATE ARTERY

Introduction

The medial femoral condyle (MFC) vascularized corticoperiosteal flap has been well described for the treatment of nonunion with minimal bone loss.   Recent applications of this donor site as a corticocancellous flap for large intercalary defects has brought into question the vascular territory of bone supplied by the descending geniculate artery (DGA) pedicle.

Methods

In 18 cadaveric specimens, the DGA was isolated, measured, and cannulated.  Using subtraction-techniques of fluoroscopic angiography, the vascular network and proximal-most extent of periosteal perfusion was recorded using radiopaque contrast dye.

Results

The DGA was isolated in 18 cadaveric specimens branching from the superficial femoral artery 14.2cm±2.4cm proximal to the joint line of the knee.  Length of the vascular pedicle to termination on the periosteum was 7.7cm±2.2cm, at 6.5cm±1.0cm from the joint line.  All specimens demonstrated a filigree of periosteal vessels dominated by a transverse and a longitudinal branch at the level of the condyle.  Proximal perfusion was consistently noted by a large longitudinal medial metaphyseal periosteal artery (MMPA).  The MMPA demonstrated the proximal-most perfusion of the DGA at a level of 13.7cm±1.3cm proximal to the joint line. Average femur length was 47.1cm±3.1cm.  The DGA provided perfusion of 29.2%±2.3% of the total length of the medial femur.

Conclusions

The DGA provides a large and reliable region of periosteal perfusion.  This suggests that corticocancellous MFC harvest may provide the benefits of vascularized bone for large intercalary nonunion defects conventionally treated with fibula flaps.

Figure 1.  Subtraction angiography following perfusion of the descending geniculate artery and demonstration of the proximal medial metaphyseal periosteal artery.

Figure 2.  Medial femoral column following angiographic marking of medial metaphyseal periosteal artery.