Avascular necrosis of the talus: current treatment options.

AVN of the talus is a challenging disease process with respect to patho-physiology and treatment. We believe that our algorithm is a legitimate approach to aid the orthopedic surgeon in initiating a promising treatment. It is divided into different levels and allows to change between some. This is not the only way to proceed but it seems promising, especially if the long-term results with the vascularized bone grafts show revascularization of the talus. As always in medicine, the treatment needs to be individualized. Arthrodesis always should be the last option and is a challenging procedure.

Potential donor rotational bone grafts using vascular territories in the foot and ankle.

BACKGROUND: An improved understanding of the extraosseous and intraosseous blood supply of the distal aspect of the tibia, distal aspect of the fibula, cuboid, and cuneiforms should identify vascular territories that would enable surgeons to perform rotational vascularized pedicle bone-grafting procedures in the foot and ankle. METHODS: We investigated the blood supply of twenty cadaveric lower extremities using two vascular injection techniques. In order to define the extraosseous and intraosseous arterial anatomy in this region, ten specimens were sequentially subjected to injection with Batson's compound, soft-tissue digestion, and bone-clearing according to a modified Spalteholz technique. To further characterize the extraosseous vascular anatomy, the other ten specimens were injected with latex and dissected. RESULTS: We identified a consistent and previously unnamed blood supply to the distal aspect of the tibia, distal aspect of the fibula, cuboid, and cuneiforms. Four vessels, each present in all of our specimens, provided distinct vascular territories to bone. A branch of the proximal lateral tarsal artery supplied a consistent vascular territory in the cuboid with an average of fifteen nutrient vessels. Similarly, a branch of the distal medial tarsal artery to the first cuneiform supplied an average of nine nutrient vessels superior to the tibialis anterior tendon insertion. A branch of the anterior lateral malleolar artery to the fibula supplied an average of seven nutrient vessels to the lateral malleolus. A branch of the distal lateral tarsal artery provided the midsection of the third cuneiform with an average of seven nutrient vessels. In the latex-injected specimens, harvesting of the vascularized pedicle bone grafts designed from these data demonstrated their anatomic plausibility and arcs of rotation. CONCLUSIONS: Four new rotational vascularized pedicle bone grafts have been identified in the foot and ankle. These grafts were present in all of our specimens, were well vascularized, had wide arcs of rotation, and were relatively easy to harvest.

Torque resistance after fixation of Jones fractures with intramedullary screws.

BACKGROUND: Intramedullary screws frequently are used for fixation of Jones fractures of the fifth metarsal. While the ability of intramedullary screw fixation in fifth metatarsals to resist bending and tensile forces is well known, the ability to withstand torsion has not been studied. This paper compares the torsional stiffness of Jones fractures treated with 6.5-mm short- threaded intramedullary screws to those treated with 5.0-mm cannulated short-threaded intramedullary screws. METHODS: Nine fresh-frozen, matched pairs of cadaver fifth metatarsals had an acute Jones fracture simulated with an osteotomy. They were stabilized with intramedullary screws and then loaded to failure. RESULTS: The torsional stiffness of the metatarsals fixed with the 6.5-mm did not differ significantly from that using 5.0-mm screws. However, to achieve stability, the 5.0-mm screw had to be long enough to reach the metatarsal head and neck. This tended to straighten the normally curved fifth metatarsal bone and caused lateral gapping at the fracture site. CONCLUSION: Both 5.0-mm or 6.5-mm screws provide equal torsional rigidity, but 5.0-mm screws may need to be longer, which could potentially straighten the fifth metatarsal shaft in patients who have a curved fifth metatarsal.