Correlation of postoperative bone scintigraphy with healing of vascularized fibula transfer: a clinical study

Treatment Options for Nonunion With Segmental Bone Defects: Systematic Review and Quantitative Evidence Synthesis

OBJECTIVES

To determine which reconstruction treatment of long bones nonunion with segmental bone defects (SBDs) is effective to restore bone length and union with good function.

DATA SOURCES

PubMed was used to identify published literature on treatment of SBD caused by fracture nonunion regardless of infection between January 1975 and December 2014.

STUDY SELECTION

We included retrospective cohort studies with a minimum sample size of 10 consecutive patients with minimum follow-up of 18 months and available data on radiographic and functional outcomes.

DATA EXTRACTION

Literature review revealed 24 publications with a sample size of 504 patients (395 males, 109 females). Data on bone union and functional outcome and complications were collected and analyzed based on validated classification systems.

DATA SYNTHESIS

Two outcome groups were categorized for bone union and functional outcome, success, and failure. We then performed heterogeneity test to examine the variability or differences in the methods used by these studies and based on that we determined whether the fixed effect or random effect method is appropriate in examining the summary or pool estimate. Pool estimate was examined for bone union and functional outcome in each surgical modality and in each anatomic location when data were available.

CONCLUSIONS

Treatment of SBD can be challenging. This quantitative evidence synthesis shows that bone union was achieved by different procedures with variable bone union and functional outcomes.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Femoral head bone viability after free vascularized fibular grafting for osteonecrosis: SPECT/CT study

PURPOSE

To evaluate femoral head bone viability following free vascularized fibular grafting (FVFG) for osteonecrosis using SPECT/CT imaging.

METHODS

Ten hips (9 patients) with osteonecrosis of the femoral head (ONFH) undergoing FVFG were prospectively enrolled. Four cases showed ARCO stage II, while six showed ARCO stage III. The mean age at surgery was 15.7 years (range, 13-22 years). Hip Harris Score (HHS) was measured pre- and post-operative. Bone scintigraphy with SPECT/CT was performed at 2 weeks and 6 months following surgery.

RESULTS

Mean follow-up was 4.0 years (range, 2-5.9 years). Mean HHS increased from 37.2 to 92.3. SPECT/CT findings revealed a progressive increase of femoral head uptake in all cases, suggesting subchondral graft bone viability. No progressive deformation of the femoral head was evidenced in radiographic evaluation at final follow-up.

CONCLUSIONS

This study demonstrates FVFG's capacity for revitalizing femoral head subchondral bone grafting in patients with ONFH, surgically treated following Urbaniak's technique. © 2015 Wiley Periodicals, Inc. Microsurgery 36:573-577, 2016.

Double-strut free vascular fibular grafting for reconstruction of the lower extremities

This article reports our experience on the treatment of long-bone defects with double-strut vascular fibular graft in 11 patients. The defects were 6-12 cm in length while 10-25 cm of vascular fibular grafts were harvested. Nine patients achieved solid union in 6 months, and two patients required additional procedures to achieve solid union. No major complications were observed, except for three patients. who had knee stiffness due to long-term immobilization and one patient who had experienced a stress fracture because of strenuous exercise at 10 months after grafting procedures. Bone union in this patient was achieved 3 months after reapplying an external fixator. It is suggested that a rigid external or internal fixator is mandatory in the course of treatment for facilitating early knee mobilization to prevent exacerbation of already compromised knee-joint motion. Vigorous exercise should be avoided for at least 12 months after solid union of the graft to prevent graft fracture. We concluded that the double-strut vascular fibular graft is an effective treatment for complicated long-bone defects of lower extremity.

Concomitant ipsilateral pedicled fibular transfer and free muscle flap for compound tibial defect reconstruction

Three patients with compound injuries of the lower extremities were treated with pedicle fibular grafts and a free muscle flap concomitantly. There were 1 female and 2 male patients, all of whom sustained high-energy trauma in a motor vehicle accident. The bone defect of the tibia ranged from 8 to 12 cm. The size of the soft-tissue defect ranged from 24 x 15 cm to 28 x 15 cm. All patients underwent preoperative angiography to ensure the patency of the peroneal artery and to avoid its use by risking viability of the leg. All patients were treated with an antegrade-flow pedicle fibular graft. The fibular graft was inserted as a single strut in 2 patients and as a double-barrel strut in 1 patient. The pedicle of the free muscle flap was anastomosed to the distal runoff of the fibular bone flap. All free muscle flap transfers succeeded without complication. Bone scans performed on postoperative day 7 showed viability of transferred bone. The average time to radiological union was 9 months, and the average time to full weight bearing was 12 months. Screw loosening occurred in 2 patients and osteomyelitis was noted in another patient who was treated successfully with sequestrectomy and antibiotics. Indications for this technique are a large segmental bone defect with a huge soft-tissue defect, and patency of the peroneal artery and at least one other major artery. This method provides the advantages of one-stage reconstruction, avoidance of contralateral donor site morbidity, easy control of infection, and chance for early weight bearing. When selected carefully, this technique can be considered when one wants to avoid a two-stage, two free flap transfer.

Evaluation of strength of healing fractures with dual energy Xray absorptiometry

Dual energy xray absorptiometry was investigated as a method for evaluation of the strength of closed tibial fractures. In 40 goats, a closed midshaft fracture was created in the left tibia. The fractures were stabilized with an external fixator. After 2 weeks (n = 21) and after 4 weeks (n = 19), both tibias were explanted and, using dual energy xray absorptiometry, bone mineral density and bone mineral content were measured in a 1 cm region. With nondestructive bending tests, area ratio and stiffness index were determined and torsional strength and torsional stiffness were determined with a torsional test to failure. Linear regression analysis was used to calculate the squared correlation coefficients for the relations between dual energy xray absorptiometry and the outcome of the mechanical tests. The squared correlation coefficients for the relation between bone mineral density and torsional strength, torsional stiffness, and area ratio and stiffness index were 0.72, 0.76, 0.64, and 0.72, respectively. The squared correlation coefficients for the relation between bone mineral content and these mechanical parameters were 0.72, 0.77, 0.63, and 0.77, respectively. The results using dual energy xray absorptiometry indicate the strength of healing closed fractures. Additional research is required to investigate specific aspects of this technique.

Evaluation of a free vascularized medial tibial bone graft in dogs

OBJECTIVE

To develop a free vascularized tibial bone graft based on the periosteal saphenous blood supply.

STUDY DESIGN

Preliminary anatomic study of medial tibial blood supply. In vivo comparison of a vascularized and avascular tibial bone graft.

ANIMALS

Nine canine cadavers; 14 healthy adult dogs that weighed 25 to 32 kg.

METHODS

An anatomic study of the vascular supply of the medial aspect of the tibia was performed using the Spalteholz technique. A bone graft consisting of the medial aspect of the tibia was transferred to a mandibular defect as a vascularized graft in 7 dogs and as an avascular graft in 7 dogs. Bone scans were performed to evaluate graft perfusion. Radiographic evaluation of the mandibles and tibias was performed. The dogs were killed after 60 days, five mandibles from each group were examined histologically, and two from each group were evaluated using the Spalteholz technique.

RESULTS

The saphenous vascular pedicle provides vascular perfusion to the medial tibial cortex. Bone scans and radiographic evaluations were consistent with viable bone in the vascularized grafts, and nonviable bone in the avascular grafts. Histological examination revealed live, healing bone in vascular grafts and necrotic bone in avascular grafts. Spalteholz evaluation revealed many small arborizing vessels in the vascular grafts and no organized vasculature in the avascular grafts.

CONCLUSIONS

The vascularized medial tibial cortical bone graft survived and proceeded to bony union in the mandibular body defect more readily than the avascular graft in this experimental model.

CLINICAL RELEVANCE

A vascularized medial tibial bone graft is a suitable free graft for use in reconstructing bone defects in dogs.

Assessment of vascularized fibular graft one year after reconstruction of the wrist after excision of a giant-cell tumour

We report a patient in whom the distal radius was resected for a giant cell tumour and the bone defect was replaced using a vascularized proximal fibular graft. The graft was viable and hypertrophied and normal callus formed on the distal radius. Due to chronic instability of the wrist the patient underwent revision arthrodesis 1 year after resection. Microscopic studies of the epishyseal region of the fibula showed wide necrosis of the graft with active creeping substitution. Despite the good technical result of the vascularized fibular graft, the vascularization was incomplete in the proximal epiphysis. We discuss possible reasons for this.

Treatment of large skeletal defects in the lower extremities using double-strut, free vascularized fibular bone grafting

This article reports on the use of double-strut, free vascularized fibular grafts to treat six patients with infected nonunion or traumatic bone loss in the femur or tibia after prolonged treatment and multiple operations. The defects were 6-13 cm long. Five patients achieved solid union within 6 months, and one patient required additional cancellous grafting to achieve union at the distal end of the fibula. One patient experienced a stress fracture due to strenuous exercise, and union was achieved 3 months after reapplying an external fixator. Although three patients had some restricted knee motion, all patients had a satisfactory outcome in regard to walking, and no limb-length discrepancies were noted in any patient.

Cinegammography and 3-D emission tomoscintigraphy for evaluation of revascularized mandibular bone grafts: a preliminary report

The following reports a study conducted to investigate a scintigraphic monitoring procedure for bone free flap in mandibular reconstruction. This procedure is based on the one hand, on vascular and bone cinegammography, and on the other hand, on vascular and bone 3-D tomoscintigraphy. We used a prospective cohort study design. All patients who underwent free flap mandibular reconstruction from April 1993 to April 1998 in the Salpêtrière University Hospital, France (20 cases) have been evaluated in relation to this scintigraphic procedure. Vascular and bone scintigraphy were performed within the second week after surgery during 2 consecutive days. All images were read by one author (J.- Y. B.), who did not know the skin status of the flap. The results were compared with the viability of revascularized bone grafts as evaluated by the skin status and Greenberg classification based on bone radiographs three months after reconstruction. Vascular cinegammography seems to be closely related to anastomosis patency. Bone cinegammography gives appreciable information on bone viability. 3-D vascular tomoscintigraphy remains difficult to interpret. 3-D bone tomoscintigraphy gives precise information on the viability of the different segments of the bone flap. These results suggest that vascular and bone 3-D tomoscintigraphy coupled with cinegammography have an excellent prognostic value. In the event of partial failure it can give information on the location of the impaired patency and on the osseous fragment which has lost any viability.

Infection of vascularized fibular grafts

Between June 1978 and July 1991, 64 limb reconstructions were done using vascularized fibular grafts. Of these, 10 became infected. Five grafts were proven viable, whereas the other 5 were proven nonviable based on the survival of the skin in the composite osteocutaneous graft and from bone scans, angiograms, and biopsies. A distinct difference in the radiologic manifestation and clinical course of the infection was noted between the viable grafts and nonviable grafts. The viable grafts showed radiologic changes of osteomyelitis that were localized, and the graft incorporated, healed with antibiotics, and exhibited graft hypertrophy. In the nonviable grafts, the radiologic changes were extensive, evidence that resorption of the grafts had resulted. This suggests that, because of the poor prognosis associated with infection of the nonviable vascularized fibular grafts, the infected grafts should be removed early to minimize the morbidity and to shorten the protracted course associated with infection. With the infected viable grafts, efforts at salvaging the graft with multiple debridements and systemic antibiotics were rewarding.

Vascularized bone grafts

Free vascularized bone grafts allow living bone tissue to be transplanted to replace a bone defect. The use of vascularized bone grafts requires microvascular dissection and attachment to a recipient site artery and vein, whereas rotational or pedicle grafts are moved, while still attached to their blood supply, to a new site. Conventional nonvascularized bone grafts heal by resorption and creeping substitution. The major benefits of vascularized bone grafts are more rapid and complete incorporation of the graft which provides immediate structural support, the ability of the transplanted (living) bone to form new bone, and the addition of new blood supply to the recipient area. The technique of the free vascularized fibula transplantation is described.

Techniques of postoperative blood flow monitoring after free tissue transfer: an overview

Ever since free tissue transfer has been established in microsurgery, success rates have greatly improved over the years, partly due to improved technical performance of microvascular anastomoses with better optical and instrumental aids. However, flap failure still occurs in 5-10%, mainly due to blood vessel thrombosis within the first 24 postoperative hours. Salvation rates of failing free tissue transfers can be optimized by in-time diagnosis of irreversibly compromised tissue blood flow and immediate operative reexploration. Therefore, there is a special demand for adequate and reliable postoperative monitoring techniques. This article gives an overview of all monitoring techniques, which have been performed both in the experimental and clinical setting thus far.