Vascularized Rib Grafts to Augment Spinal Fusion: A Novel Approach

Abstract

BACKGROUND: Pseudoarthrosis is a well-known complication following spinal fusion. Rates range from 5% to 40% and are influenced by both patient factors and technical factors. Patients with pseudoarthrosis may experience a return or worsening of their preoperative pain, which can significantly decrease quality of life. For patients with complex posterior column defects with either anterior or posterior columnar insufficiency, especially those receiving chemotherapy, radiation, predisposed to recurrent pseudarthrosis or infection, vascularized bone grafts (VBGs) have been shown to provide better outcomes than nonvascularized bone grafts (N-VBGs).1–5 The purpose of this study is to present an innovative pedicled rib VBG (R-VBG) that can be utilized to augment instrumented spinal fusion. METHODS: Following hardware placement for spinal fusion, an incision is made over the target rib. The intercostal muscle attachments to the superior border of the R-VBG are released, and the rib with its blood supply intact is bluntly dissected from the underlying pleura and inferior intercostal muscle attachments, protecting the subcostal vessels. Particular care is taken when separating the intercostal nerve from the subcostal vessels to prevent postoperative numbness and radicular pain. At the lateral limit of the dissection, the subcostal vessels were controlled, and the rib is cut distally and proximally. The R-VBG is then tunneled under the paraspinous muscles and placed along the posterolateral gutters of the spinal levels being augmented. The natural curvature of the rib is used to match the patients kyphosis/lordosis. The rib is cut down to size and fixated. RESULTS: To date, 7 R-VBGs have attempted. Of these 6 (86%) have been successfully harvested, all of which (100%) went on to achieve at least probable radiologic evidence of graft site fusion. CONCLUSION: The technique described for rotating a vascularized rib bone graft into the posterolateral space for spinal fusion as far as the L4/L5 joint space is an effective method for augmentation of spinal fusion in patients with complex spinal pathologies. Although additional data needs to be collected before true indications can be elucidated for this procedure, our preliminary prospective results suggest that this approach is relatively low risk, especially compared to free tissue transfer, and it has the benefit of providing well-vascularized, healthy bone to augment the fusion bed. REFERENCES: 1. Eastlack R, Dekutoski M, Bishop A, et al. Vascularized pedicled rib graft: a technique for posterior placement in spinal reconstruction. Spinal Disord Tech. 2007;20:610–615. 2. Bohl M, Mooney M, Catapano J, et al. Pedicled vascularized bone grafts for posterior occipitocervical and cervicothoracic fusion: a cadaveric feasibility study. Oper Neurosurg. 2018;15:318–324. 3. Bradford DS. Anterior vascular pedicle bone grafting for the treatment of kyphosis. Spine. 1980;5:318–323. 4. Bradford DS, Daher YH. Vascularised rib grafts for stabilisation of kyphosis. J Bone Joint Surg. 1986;68B:357–361. 5. Wilden JA, Moran SL, Dekutoski MB, et al. Results of vascularized rib grafts in complex spinal reconstruction. J Bone Joint Surg. 2006;88A:832–839.