Surgery STAT: Limb sparing procedure is another option for dogs
Amputation remains the standard of care to address most primary tumors of the appendicular skeleton, particularly sarcomas. As a general rule, dogs adapt well to amputation, regardless of size. However, dogs suffering from concurrent orthopedic or neurologic diseases, or those with owners opposed to amputation, may be poor candidates for this procedure. In those cases, limb sparing may be an option. As the name implies, limb sparing is a surgical procedure in which a portion of diseased bone is removed or treated while limb function is preserved.
Proper staging must be performed to ensure the procedure is in the best interest of the patient. Surgical planning to ensure appropriate margins for both soft and bony tissues is essential. Advanced imaging such as CT and MRI may facilitate this, as well as help determine whether the patient is even a candidate for limb sparing.
The techniques for limb sparing, prognosis for functional outcome and complications seen are dependent on the anatomic location of the tumor. The site most amenable to limb spare is the distal ulna. It can be removed and does not need to be replaced. Ideally, the interosseous ligament is preserved. If the styloid process must be excised with the tumor, reconstruction of the lateral collateral ligament or pancarpal arthrodesis will maintain stability of the antebrachiocarpal joint. The prognosis for limb function is usually excellent.
This technique does require maintenance of a bone bank or purchase of a commercially available cortical allograft. A metallic endoprosthesis with specialized bone plate now is available as an alternative to cortical allograft. A study comparing the endoprosthesis and cortical allograft found no difference in complication rates.
The distal radius can be replaced with viable autograft using distraction osteogenesis or transfer of an ulnar segment. Distraction osteogenesis utilizes the principles and techniques developed by Ilizarov.