Massive bone allograft engineered with autologous vessels: A new perspective for the future

Reconstruction is very important to ensure good function and quality of life after bone tumor resection. For metacarpals and phalanges, amputation and toe transfer are the gold-standard indications; nevertheless, allograft reconstruction must also be taken into account. Unfortunately, because of its inert biological behavior, it undergoes progressive resorption, with frequent fracture. Several attempts have been made to induce new vascularization in massive bone allograft, with poor results. However, neo-angiogenesis was reported with vascular loops, and we therefore hypothesized that heterologous graft integration could be enhanced by creating a vascular loop through the graft. A 50-year-old male with chondrosarcoma of the ring finger of the left hand underwent wide resection. An allogenic middle phalanx of comparable size was then prepared to fill the defect. Two small windows were performed proximally and distally on the radial surface of the allogenic phalanx, and a 4 cm-long vein graft was inserted inside the medullary canal. Metacarpophalangeal joint stability was achieved by collateral ligament reconstruction with micro-anchors. The distal part of the allograft was then stabilized to the middle phalanx with a 1.5 mm-thick micro-plate and screws. The radial proper palmar digital artery was proximally and distally sutured end-to-end to the vein graft, under microscopy. At 12-month follow-up, the allograft was fused, and histology performed at plate removal at 18 months revealed viable spindle cells with osteoblastic differentiation, without evidence of atypia, in a dense fibrous stroma. At 22 months' follow-up, the patient was apparently disease-free, and satisfied with his manual function.