Distal Extremity Injuries

Injuries of the distal extremities in dogs and cats frequently involve significant skin disruption/de-gloving or deficits and sometimes significant soft tissue loss. Salvage is dependent on ability to retain weight-bearing capability with functional pad tissue, appropriate neuro-vascular supply and adequate digital and meta-carpal or meta-tarsal bone stock for transfer of ground reaction forces to the limb. Minimising propensity for on-going pain and optimising functional capability are key goals and these injuries can be career-ending for some working dogs, or at least lifestyle changing for many dogs and cats. Various skin and soft tissue reconstruction techniques such as podoplasty, digital pad transfer, muscle and skin grafts can be effectively employed and are well described in the veterinary literature, as are multiple fracture and joint reconstruction techniques. The percentage of circumferential injury where second intention healing or skin-stretching techniques prior to secondary closure can be utilized is 30%. Free skin grafts can be used to facilitate wound resolution once sufficient debridement and preparation of a good quality granulation bed has taken place. The reverse saphenous conduit flap is useful for treatment of wounds involving the tarsus and metatarsus. A prerequisite for the success of this flap is the absence of trauma to the medial saphenous vascular system as well as maintenance of the deep vascular structures of the metatarsus and paw. Hinge or pouch flaps, where the limb is inserted in a pocket of skin on the flank of the animal can be useful in the management of distal limb traumas where significant soft tissue injury is involved. However, these flaps require on-going patient hospitalization and patient compliance can be a problem. Microvascular free tissue transfer can also be implemented in the treatment of distal limb soft tissue deficits but specialist training and equipment and is required. Crush injuries are a particular challenge and various novel external frames may be very helpful for supporting osseous structures and also facilitating appropriate wound care with topical hydrogels and dressings. Vacuum-assisted closure is also a recently-available and very valuable adjunct to facilitate functional recovery of skin and soft-tissue. The aim of this presentation is to present some advances in treatment options for challenging distal limb trauma. Some examples are listed.