Surgeon's Corner: Forelimb Amputation

Surgery

During forelimb amputation, the patient is placed in lateral recumbency with the affected limb on top. A teardrop-shaped skin incision is made around the extremity beginning at the top of the scapula and running in a smooth continuous fashion down the lateral aspect over the scapular spine. The incision then forms a teardrop shape with the caudal aspect extending over the latissimus dorsi and into the axillary region and cranial aspect across the scapulohumeral joint. The leg is abducted and the two incisions are connected medially across the pectoral muscles, with care to incise only the skin and SC tissues. Large cutaneous vessels on the lateral aspect of the limb are identified, double ligated and transected between the ligatures.

The fascia distal to the omotransversarius is dissected with scissors, then incised along the spine of the scapula to incise the attachments of the omotransversarius and cranial and caudal trapezius muscles directly off of the spine. Care is taken to preserve as much muscle as possible. A blade is then used to remove the rhomboideus muscle from the cranial and dorsal aspect of the scapula. The serratus ventralis is dissected from its origin on the medial aspect of the scapula using a periosteal elevator or scissors. The brachiocephalicus muscle is then cut from its attachment at the humerus. The scapula is avulsed laterally exposing the brachial plexus. Nerve bundles making up the brachial plexus are injected with bupivacaine and then transected with scissors or a blade prior to exposure of the axillary artery and vein. The axillary artery is double ligated using encircling and transfixing ligatures. In most cases, a double encircling ligature (without transfixation) is all that is necessary for the thin-walled axillary vein.

The leg is replaced in the normal position and the latissimus dorsi is carefully dissected, preserving as much of the muscle as possible which will serve as protection for the patient’s chest wall. The lateral thoracic artery, vein and nerve should be identified and individually ligated before the latissumus dorsi is amputated from its insertion on the humerus. In large-breed dogs these can be sizable vessels. 

The extremity is again abducted and both the superficial and deep pectoral muscles are excised from their humeral attachments. Again, preserving as much of the pectoral muscle as possible is important, as these muscles will also serve as a protective covering for the patient’s chest. Remaining loose connective tissue in the axillary region is excised and the limb is removed. The area is lavaged and surgical site inspected for adequate ligation of all vessels. To close the area, the pectoral muscles are brought from distal to proximal, the latissimus dorsi from caudal to cranial and the omotransversarius and trapezius brought from cranial to caudal. These are all closed using a simple continuous appositional suture pattern. These muscles should offer a very secure and protective layer over the exposed chest wall. The subcutaneous tissue and skin are closed with a simple continuous pattern. The final closure will generally have a triangular pattern.

Outcome

The patient does well one day postoperatively, as most quadrupeds adjust quickly to a tripod stance after either a fore or hind limb amputation. In just a few months, these patients are almost completely back to normal functionality.

Surgeon’s Corner is intended as a forum for those with specialized expertise to share their approaches to various techniques and procedures. As such, the content reflects one expert’s approach and has not been peer reviewed.

This video was authored by Howard B Seim III, DVM, DACVS. Other surgical videos are available through VideoVet.