The longitudinally split vascularized fibula with a vascularized periosteal flap for the reconstruction of large segmental bone defects of the tibia

Abstract

A new principle in reconstructive surgery is presented: “The immediate reconstruction of a missing bone segment with a primary osteoperiosteal tube that will secondarily be transformed into a complete osseous tube. ” In 5 out of 7 baboons, a bone tube with an almost normal bone cavity was achieved after 16 to 28 weeks. In 2 cases, we failed to reconstruct the tube because of an intraoperative fault and postoperative plate fracture with subsequent destruction of the vascularized periosteal flap. On the basis of this study, we describe a new concept in reconstruction of segmental bone defects of the lower extremity. The osteoperiosteal tube is formed by the combination of two successful experimental and clinical techniques: the vascularized fibular transfer which is modified by splitting the bone graft longitudinally, and transfer of vascularized periosteum (“concept of the substitution of a missing bone segment by an organ-like tube”). In the most stressed marginal region of the bone defect, there is vascularized cortical bone from the longitudinally split fibular graft and an increasing amount of lamellar bone being produced under the vascularized periosteal flap. By splitting the graft, nutrition depends entirely on the periosteal blood supply. The “concept of the dual blood supply” was initially described by Berggren et al. and Papanastasiou et al. [4, 18]. The significance of the “concept of the vascularized periosteum transfer for reconstruction of a segmental bone defect” is well illustrated. Only in cases where the vascularized periosteal flap was intact and securely sutured to the fibulae graft and the two tibia stumps could a bone tube be reconstructed. The arrangement of both vascularized grafts as an osteoperiosteal tube exemplify the “concept of the given space” as described by Stock et al. [26]. Inside the osteoperiosteal tube, a “consolidation chamber” is created in which all the factors required for bone formation can be concentrated. Comparison of the results of successfully reconstructed bone tubes with the solid bone column in the defect of the baboon where no bone tube could be reconstructed underline the “concept of combination of different vascularized grafts for reconstruction of segmental bone defects in long bone defects of the lower extremity.”