Massive bone allografts for limb salvage

Soft-tissue flap coverage maximizes limb salvage after allograft bone extremity reconstruction

Limb salvage after extremity tumor ablation may include the use of allograft bone. The primary complication of this method is infection of the allograft, which can lead to limb loss in up to 50 percent of cases. The purpose of this study is to evaluate the efficacy of primary muscle flap coverage in the setting of allograft bone limb salvage surgery. This study is a prospective review of all patients with flap coverage of extremity allografts over the 10-year period 1991 to 2001. There were 20 patients (11 male and nine female patients) with an average age of 28 years (range, 6 to 72 years). Flap coverage was primary in 16 patients and delayed in four. Delayed coverage was performed for failed wounds that did not have a primary soft-tissue flap. Pathologic findings included osteosarcoma in nine patients, Ewing sarcoma in five patients, malignant fibrohistiocytoma in two patients, chondrosarcoma in two patients, synovial sarcoma in one patient, and leiomyosarcoma in one patient. Allograft reconstruction was performed for the upper extremity in 12 patients and for the lower extremity in eight patients. Flap reconstruction was accomplished with 20 pedicle flaps in 17 patients (latissimus dorsi, 12; gastrocnemius, four; soleus, three; and fasciocutaneous flap, one) and four free flaps (rectus abdominis, three; latissimus dorsi, one) in four patients. All pedicled flaps survived. There was one flap failure in the entire series, which was a free rectus abdominis flap. This case resulted in the only limb loss noted. The follow-up period ranged from 1 to 50 months (average, 12.35 months). At the time of final follow-up, three patients were dead of disease and 17 were alive with intact extremities. The overall limb salvage rate in the setting of bone allograft and soft-tissue flap coverage was 95 percent (19 of 20). Reoperation for bone-related complications was required in 50 percent (two of four) of cases receiving delayed flap coverage compared with 19 percent (three of 16) of patients with primary flap coverage (statistically not significant). The results of this study support the use of soft-tissue flap coverage for allograft limb reconstruction. In this series, no limb was lost in the setting of a viable flap. Reoperation was markedly reduced in the setting of primary flap coverage. Pedicled or microvascular transfer of well-vascularized muscle can be used to wrap the allograft and minimize devastating wound complications potentially leading to loss of allograft and limb.

Limb sparing using a double bone-transport technique for treatment of a distal tibial osteosarcoma in a dog

OBJECTIVE

To evaluate the treatment of a spontaneously occurring osteosarcoma in a dog by means of tumor resection and bone regeneration of a 12-cm defect using double bone transport.

STUDY DESIGN

Case report.

ANIMALS OR SAMPLE POPULATION

An 11 year-old client-owned German shepherd.

METHODS

After tumor resection, a preassambled Ilizarov frame was secured to the proximal tibia and to the tarso-metatarsal region. Two osteotomies were performed in the proximal metaphysis. The two bone segments were transfixed with 1.5-mm-diameter wires, each secured to a ring, and bone transport was performed until the distal segment reached the talar surface. Cisplatin was administered 14, 35, and 59 days after surgery.

RESULTS

Bone regenerate was first visible radiographically 4 weeks after surgery. The frame was removed 162 days after surgery. The hock was protected with a plaster cast because the tarsal arthrodesis was not complete. The dog underwent tibiotarsal arthrodesis 201 days after osteosarcoma resection. The dog died of metastatic disease 239 days after the initial surgery.

CONCLUSIONS

Even though this dog died of systemic metastases, local recurrence did not develop. Cisplatin chemotherapy did not appear to negatively affect bone regeneration.

CLINICAL RELEVANCE

To our knowledge, the double transport technique has not been previously described in the veterinary literature. In this dog, this technique decreased the duration of treatment compared with a conventional single-segment transport technique.