Vascularised pedicular bone grafts

Summary When a massive free bone graft has to be incorporated into a large bone defect in the presence of a poor vascular recipient bed, the risks of absorption and failure of the graft to revascularise are high. Experimental studies have confirmed that a bone graft transferred to its recipient site with an intact pedicle of blood supply remains viable, and unites directly with the recipient bone without having to be revascularised and replaced by creeping substitution. It also provides a live bone bridge for reconstruction of a massive bone defect, and is a ready source of vascular osteogenic tissue which sprouts new outgrowths to revascularise avascular recipient bone. A vascularised bone graft can be raised on a pedicle of muscle attachment or a main axial vessel, but the mobility of the vascularised pediculated graft is limited by the length of its pedicle.The vascularised muscle-pedicle graft of the ipsilateral fibular shaft described by Chacha et al has been proved viable both in monkeys and in humans. The shaft is raised on a pedicle of the peroneal vessels and the peroneal and the anterior tibial muscles, and provides an excellent viable bone strut to bridge a large defect in the tibial shaft.Judet's quadratus femoris muscle-pedicle graft from the greater trochanter has proved superior to Phemister's tibial cortical or fibular strut graft for the treatment of non-union of the femoral neck and the silent-phase of avascular necrosis of the femoral head. The tensor fascia lata muscle-pedicle graft of the anterior iliac crest, described by Davies and Taylor, provides a good viable bone strut for anterior hip fusion and for filling defects in the acetabulum and the upper femur. The whole of the greater trochanter attached to a thick pedicle of the gluteal muscles can be used as a live extra-articular graft for hip fusion. A pedicular rib graft raised on its intercostal vessels, as described by Rose et al. and Bradford, is a very useful live bone strut for correction of kyphosis and grafting of infective lesions of the vertebral bodies.The cortical graft of the radius within the radial forearm skin flap for reconstruction of the thumb, the pronator quadratus muscle-pedicle graft of the lower radius for non-union of the scaphoid and avascular necrosis of the lunate, and the erector spinae muscle-pedicle graft of the posterior ilium for intertransverse fusion are new concepts which need to be evaluated for wider clinical application.

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Résumé Lorsqu'une greffe osseuse libre, de volume important, doit combler une vaste perte de substance dans une région mal vascularisée, il existe un risque majeur de résorbtion du greffon par échec de la revascularisation. Les études expérimentales ont confirmé qu'un greffon osseux transféré avec son pédicule vasculaire intact reste vivant et fusionne directement avec l'os receveur sans qu'il ait besoin d'être revascularisé et réhabité par le mécanisme de la «creeping substitution». Il constitue également un pont osseux vivant lors de la reconstruction d'une perte de substance osseuse étendue ainsi qu'une source de tissu ostéogénique qui enverra des bourgeons vasculaires capables de réhabiter l'os receveur dévascularisé. Un greffon osseux vascularisé peut être alimenté par un pédicule relié aux insertions musculaires ou par une artère nourricière principale, mais sa mobilité sera limitée par la longueur du pédicule.On a démontré, aussi bien chez le singe que chez l'homme, que la greffe de péroné homolatéral vascularisée par un pédicule musculaire, décrite par Chacha et coll. restait vivante. Le greffon est irrigué par une branche des vaisseaux péroniers, par l'intermédiaire des muscles péroniers et jambier antérieur. Il constitue un excellent étai osseux vivant, capable de ponter une perte de substance tibiale étendue.La greffe pédiculée de Judet provenant du grand trochanter s'est montrée supérieure au greffon cortical tibial ou péronier de Phemister dans le traitement de la pseudarthrose du col du fémur et la prévention de la nécrose de la tête fémorale. La greffe pédiculée par le tenseur du fascia lata de la crête iliaque antérieure, décrite par Davies et Taylor, fournit un bon greffon vivant pour placer sur la face antérieure d'une arthrodèse de hanche ou pour combler une perte de substance du cotyle ou de l'extrémité supérieure du fémur. La totalité du grand trochanter relié à un épais pédicule provenant des muscles fessiers peut être utilisée comme greffon vascularisé extra-articulaire lors d'une arthrodièse de hanche, Un greffon costal irrigué par les vaisseaux intercostaux, tel que l'ont décrit Rose et coll. et Bradford, peut être très utile lors de la correction des cyphoses ou pour le comblement de lésions d'ostéite des corps vertébraux.Le greffon radial prélevé avec un lambeau cutané d'avant-bras pour reconstruction du pouce, la greffe pédiculée par le carré pronateur de l'extrémité inférieure du radius pour pseudarthrose du scaphoïde ou nécrose du semi-lunaire et la greffe pédiculée par les muscles lombaires de la crête iliaque postérieure pour arthrodèse inter-transversaire, sont de nouvelles possibilités qui nécessitent, pour être évaluées, une plus large application clinique.

     

Vascularised bone grafts for the management of non-union

Non-union of the long bones may have severe consequences, particularly when combined with other post-traumatic sequelae, such as tendon adhesions, reflex sympathetic dystrophy and infection, among others. In these cases, it is important to treat the delayed union or non-union first or at the same time with the other problems in order to achieve adequate function. Once the normal bony healing process has been slowed or stopped, it is necessary to provide both stability to the fracture site, as well as a biological stimulus for the fibrocartilagenous callus to finish the healing process. Vascularised grafts, such as the free fibula, offer not only structural support, but also promote bone healing. The later is achieved by trabecular bone formation, as well as vascular sprouting from pedicle vessels.     

Combined use of platelet-rich plasma and autologous bone grafts in the treatment of long bone defects in mini-pigs

The use of platelet-rich plasma (PRP) for improving of bone defect healing is discussed controversially. The aim of this study was to assess the effect of PRP in combination with autologous cancellous graft on bone defect healing in a critical metaphyseal long bone defect. A critical size defect in the tibial metaphysis of 16 mini-pigs was filled either with autologous cancellous graft as control group or with autologous cancellous graft combined with autologous PRP. Compared to native blood platelets were enriched about 4.9-fold in the PRP. After 6 weeks, the specimens were assessed by X-ray and histological evaluation. Histomorphometrical analysis revealed that the area of new bone was significantly higher in the PRP group concerning the central area of the defect zone (p < 0.02) as well as the cortical defect zone (p < 0.01). All defects showed substantial new bone formation, but only defects of the PRP group regenerated entirely. The PRP group was superior to the control group even in the semi-quantitative assessment of the osseous bridging in both observed areas of the defect. Within the limits of the present study it could be demonstrated that PRP combined with autologous cancellous graft leads to a significantly better bone regeneration compared to isolated application of autologous cancellous graft in an in vivo critical size defect on load-bearing long bones of mini-pigs.     

Vascularised nerve grafts

Since Taylor (1976) successfully performed the first vascularised free nerve graft, experimental and clinical data have not provided conclusive support for the superiority of this method of repairing loss of nerve substance.Experimental work yields conflicting results. Histologic results are in favour of vascularised grafts but non-vascularised fascicular grafts placed in a healthy bed recover sufficient neovascularisation within a short period of time (four to six days).In the field of brachial plexus repair, vascularised grafts give consistent results. However, if thrombosis of the anastomoses occurs, the grafts fail completely.In our experience, vascularised nerve grafts used for repairing digital nerves and arteries, have a high rate of thrombosis.There are few potential donor sites. A nerve graft cannot be considered to be physiologically vacularised if it relies only on an artery or on an arterialised vein. Given the present state of immunosuppressant treatments, vascularised allografts are not yet appropriate.Therefore, vascularised nerve grafts have limited applications. In general it is preferable to repair the tissue bed so as to promote revascularisation of conventional nerve grafts.     

Vascularised bone transfer for defects and pseudarthroses of forearm bones.

During a five-year period, 15 patients with defects or pseudarthroses of the forearm bones were operated on. All had previously undergone one to six conventional operations. A vascularised fibular graft was used in ten cases, a radial graft in three cases and a humeral graft in two cases. Bone graft viability and healing were assessed clinically and patients have been observed for seven months to five years. 14 patients have finished treatment: 13 were cured and only two repeat osteosyntheses were required. In one case there was resorption of the central part of the fibular graft. Primary bony union was achieved in three to six months. Care must be taken in precise pre-operative assessment of the state of the forearm arteries. We advocate wider usage of vascularised radial and humeral grafts.     

Vascularised rib grafts for stabilisation of kyphosis

The results of vascularised rib graft transfers are analysed in 25 patients followed up for more than two years (average 34 months). Radiographs showed early and rapid incorporation of the grafts in 4 to 16 weeks (average 8.5 weeks); external immobilisation averaged 11 weeks (range 5 to 24 weeks). The technique seems a useful alternative to allografts or homografts employing an avascular rib or fibula since it promotes rapid healing without needing microsurgical techniques.     

因病施治合理治疗长骨节段性缺损

长骨节段性缺损往往继发于高能量损伤或肿瘤切除,其修复是骨科医生面临的一个难题.     

Vascularised bone graft for the treatment of non-union of the scaphoid.

A 4/5 compartment pedicled vascularised bone graft from the distal radius combined with internal fixation with a Herbert type cannulated screw was used to treat non-union fractures of the proximal pole of the scaphoid in 13 patients. Non-union was identified on plain radiographs alone. Uneventful clinical and radiological healing was achieved in 11 patients. One patient had progressive signs of failure of the fixation of the screw at the proximal pole; the screw was changed and the fracture was stable at reoperation. One patient had a fall postoperatively, radiographs taken at follow-ups showed only partial healing, and he had a bone graft 12 months later. Twelve patients had clinical and radiological union of the fracture, and one patient fibrous healing alone. The technique may improve healing of non-union of fractures of the proximal pole of the scaphoid, but it is still a technical challenge.     

Vascularised fibular grafts as a salvage procedure in failed intercalary reconstructions after bone tumour resection of the femur

Vascularised fibular grafts (VFGs) are widely used for primary reconstruction of long bones after bone tumour resections. The biological properties of VFGs are such that they can be a useful option even in failed intercalary reconstructions. The purpose of the current study was to investigate the results and the morbidity of VFGs as a salvage procedure in failed previous reconstructions after intercalary bone tumour resection of the femur. Our series included 12 patients, treated from April 1989 to March 2005, with an average age of 23 years (range 10–43 years) at presentation. The initial diagnosis was osteosarcoma in 10 cases and Ewing's sarcoma in two cases. All patients received chemotherapy and none received radiation therapy. Seven patients received VFG as biologic augmentation in intercalary allograft non-union and in the other five patients, a combination of allograft and VFG was used to replace a cement spacer with hardware failure (four patients) and a failed intercalary prosthesis (one patient). Three patients died during follow-up, in all cases because of metastatic disease. At an average follow-up of 147 months (range 11–260 months), the remaining nine patients were continuously disease-free. Complete healing of the osteotomy of both allograft and VFG was observed in 10 patients at final follow-up. Two major complications were observed that required surgical revision, eventually healing in one case and leading to a poor functional outcome in one case. Significant hypertrophy of the VFG was detected in seven of nine evaluable patients. At final follow-up the mean Musculoskeletal Tumour Society (MSTS)’93 functional score of the nine evaluable patients was 90% (range 66–100%). These results indicate that VFG is a valid salvage procedure in failed intercalary reconstructions of the femur after bone resection.     

Postoperative monitoring of free vascularized bone grafts in reconstruction of bone defects

Vascularized bone transfer is increasingly recognized as a very useful and versatile technique for reconstructing large bone defects. It is especially indicated in patients with challenging conditions, such as nonunions, postoncologic resections, severe trauma, and congenital defects. With increasing experience of reconstructive surgeons, improved microsurgical techniques, and more enhanced flaps, the failure rate of free flaps has been reduced in the last decades. Especially, the early‐postoperative period is decisive in the outcome of surgery. Several techniques have been described for monitoring the postoperative viability of microsurgical free vascularized graft, and their sensitivity and reliability continues to be the object of animal experiments and clinical trials. The qualities of an optimal monitoring device should be objective, continuous, noninvasive, safe, reproducible, easily managed, and interpretable for the nursing staff, inexpensive, and a clear indicator of changes in arterial and venous circulation. Presently, no one neither fulfills all of the criteria completely nor is uniformly accepted. In this article, relative advantages and disadvantages of these various postoperative monitoring techniques are discussed. © 2009 Wiley‐Liss, Inc. Microsurgery 2009.     

Vascularised fibular grafts. An experience of 102 patients

The results and complications of 104 vascularised fibular grafts in 102 patients are presented. Bony union was ultimately achieved in 97 patients, with primary union in 84 (84%). The mean time to union was 15.5 weeks (8 to 40). In 13 patients, primary union was achieved at one end of the fibula and secondary union at the other end. In these patients, the mean time to union was 31.1 weeks (24 to 40). Five patients failed to achieve union, with a resultant pseudarthrosis (3 patients) or amputation (2 patients). There were various complications. Immediate thrombosis occurred in 14 cases. In two of 23 patients with osteomyelitis, infection recurred at two and six months after surgery, respectively. Both patients had active osteomyelitis less than one month before the operation. Bony infection occurred in a patient with a synovial sarcoma of the forearm one year after surgery. In 15 patients, 19 fractures of the fibular graft occurred after bony union, all except one within one year after union. In patients in whom an external fixator had been used, fracture occurred soon after its removal. Union was difficult to achieve in cases of congenital pseudarthrosis of the tibia. Appropriate alignment of the fibular graft is an important factor in preventing stress fracture. The vascularised fibula should be protected during the first year after union. Postoperative complications at the donor site included transient palsy of the superficial peroneal nerve in three patients, contracture of flexor hallucis longus in two and valgus deformity of the ankle in three. Vascularised fibular grafts are useful in the reconstruction of massive bony defects. We believe that meticulous preoperative planning, including choosing which vessels to select in the recipient and the type of fixation devices to use, and care in the introduction of the vascularised fibula, can improve the results and prevent complications.     

Vascularised bone graft applications in upper extremity problems

Between 1990 and 1996, 16 cases of bone defects were treated by vascularised bone grafting by the authors. Free vascularised fibula was used in 10 cases and one free iliac crest graft was used for upper extremity bone defects. Four vascular pedicled first metacarpal bone and one radial styloid bone were used for scaphoid nonunion. Average follow-up was 26 months (6–78 months) and success rate was 94%. We recommend vascularised bone grafts in the upper extremity when there is risk of infection; the defect is greater than five centimeters when the forearm rotation is unlimited. The avascularity of the scaphoid pseudarthrosis must be verified radiologically or through magnetic resonance imaging. This technique should only be used when other reconstructive techniques are unlikely to succeed. © 1998 Wiley-Liss, Inc. MICROSURGERY 18:160–162 1998     

Vascularized fibular grafts for the reconstruction of segmental tibial bone defects

Free vascularized fibular grafts were employed in seven patients with large tibial defects following trauma or resection of tumour. All patients were followed for more than 5 years. Tibial union and excellent functional results were achieved in all seven patients. Free vascularized fibular transfer seems to be an effective method of treatment for massive segmental bone defects.     

A study of autologous cancellous bone particles in long bone discontinuity defects

Long bone discontinuity defects in dogs were restored by particulate autologous cancellous bone grafts and a Dacron-urethane mesh implant. In six months the discontinuity defects were filled by new bone formation, which was analyzed histologically, radiographically, and by densitometric methods. The postulated mechanism is a field phenomenon of bone induction. The discontinuity defects remained unrestored in the control groups without bone graft material. In the dogs killed at three months incorporation of the graft material was incomplete in the central area of the defect.