The Surgical Technique

Surgery is performed simultaneously by two teams. While the tumor team performs the resection, the microsurgical team harvests the controlateral fibula. Usually, the VFT must exceed the length of the oncologic resection by approximately five centimeters. Microsurgeons and tumor surgeons worked in collaboration during resection. The microsurgeon isolates and protects the recipient vessels.

In combined bone graft procedures the VFG can be used in concentric assembling or in parallel dual assembling, with the allograft.

The concentric technique is recommended for tibia reconstruction6 where soft tissue closure is difficult. In the event of a skin defect, an osteocutaneous flap may be planned: otherwise, a local muscular flap may be rotated to cover the implant. In our experience only in one case of large soft tissue defects, a free latissimus dorsi flap was prepared.

An oversized allograft should be used given that a wide medullary canal can contain the fibula. The anterior cortex is opened and the medullary canal is reamed until the fibula fits into it (Fig. 10C.1). Great care must be taken to avoid damage to the vascular pedicle during the insertion of the fibula into the allograft shell. The positions of the vascular pedicle of the VFT and that of the recipient vessels must be evaluated before osteosynthesis. Any traction, change in angulation, twisting or pressure on the pedicle must be avoided. A groove can be carved into the allograft to obtain a "safe" position for the vascular pedicle, thus avoiding any impingement on any sharp margin. The microsurgical team must cooperate with the tumor team during preoperative planning. All the variables that can interfere with the microvas-cular outcome, must be taken into consideration.

In cases of intraepiphyseal resection, where just a thin part of the epiphysis and the articular surface are saved, the use of concentric assembling allows for minimal juxta-articular osteosynthesis with the use of multiple screws. When the growth plate is preserved, bone fixation is performed by passing Kirschner wires through the epiphysis in order to prevent ephiphysiodesis. At the other end of the combined graft, fixation is usually achieved using plate and screws. If sufficient bone is spared at both ends of the resection, rigid fixation is carried out using a long plate, which crosses both osteotomies.

Table 10C.1. Histological diagnosis of treated patients

Diagnosis N° of Cases

Osteosarcoma 28

Ewing's Sarcoma 10

Adamantinoma 4

Fibrosarcoma 3

Malignant Fibrous Histiocitoma 3

Dedifferentiated Chondrosarcoma 1

Angiosarcoma 1

Desmoplastic Fibroma 1

Giant Cell Tumor 1

TOTAL 52

Fig. 10C.1. Example of combined bone graft procedure. The VFG is used in concentric assembling for tibia reconstruction.

Fig. 10C.1. Example of combined bone graft procedure. The VFG is used in concentric assembling for tibia reconstruction.

Parallel dual assembling is widely used in diaphyseal reconstruction of the femur (Fig. 10C.2). In such cases the allograft is used for intercalary reconstruction and fixation is carried out using long plate which bridges the osteotomy sites: VFG is

Fig. 10C.2. Example of parallel dual assembling in diaphyseal reconstruction of femur.

fixated medially to the allograft. Extremities are placed in or are in contact with the femoral bone. This procedure can reinforce the medial cortex and permit the vascular anastomosis with branches of the deep femoral artery, which lies medially.

When the resection must be performed very close to the growth plate or to the articular surface, concentric assembling, with minimal osteosynthesis, is preferred even in the femur.

Normally in the case of tumoral resection, vascular pedicles can be found rather easily at the side of anastomosis. A termino-terminal anastomosis with the anterior tibial vessels in direct or reverse flow, was the most often used type of vascular reconstruction in the leg, in our series. Using an upside down fibula, a termino-lateral anastomosis with posterior tibial artery was sometimes but rarely performed.

After surgery, the patient is immobilized in a cast for four to six weeks. When the cast is removed, the proximal and distal joints are mobilized for a few days. A new cast is than applied for an additional period of time of at least four weeks. Afterwards, a brace must be worn until union is achieved. Once union has been achieved, progressive weight bearing is allowed.

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