Instrumented fusion of thoracolumbar fracture with type I mineralized collagen matrix combined with autogenous bone marrow as a bone graft substitute: a four-case report

• DOI: 10.1007/s00586-006-0162-4
• Publication Date: 2006-07-24T08:52:20Z
• Authors: Antonio A. Faundez; Sofia Taylor; André J. Kaelin
• Keywords: Adult; Male; Case Report; Collagen Type I/chemistry; Spinal Fusion/methods; Transplantation, Autologous; Collagen Type I; Thoracic Vertebrae; Fractures, Bone; 03 medical and health sciences; 0302 clinical medicine; Fractures, Bone/surgery; Bone Substitutes/therapeutic use; info:eu-repo/classification/ddc/617; info:eu-repo/classification/ddc/618; Humans; Device Removal; Bone Marrow Transplantation; ddc:618; Lumbar Vertebrae; ddc:617; Tissue Scaffolds; Lumbar Vertebrae/injuries; Middle Aged; Orthopedic Fixation Devices; Durapatite; Spinal Fusion; Thoracic Vertebrae/injuries; Bone Substitutes; Female; Bone Marrow Transplantation/methods

In order to avoid the morbidity from autogenous bone harvesting, bone graft substitutes are being used more frequently in spinal surgery. There is indirect radiological evidence that bone graft substitutes are efficacious in humans. The purpose of this four-case study was to visually, manually, and histologically assess the quality of a fusion mass produced by a collagen hydroxyapatite scaffold impregnated with autologous bone marrow aspirate for posterolateral fusion. Four patients sustained an acute thoracolumbar fracture and were treated by short posterior segment fusion using the AO fixateur interne. Autologous bone marrow (iliac crest) impregnated hydroxyapatite-collagen scaffold was laid on the decorticated posterior elements. Routine implant removal was performed after a mean of 15.3 months (12-20). During this second surgery, fusion mass was assessed visually and manually. A bone biopsy was sent for histological analysis of all four cases. Fusion was confirmed in all four patients intraoperatively and sagittal stress testing confirmed mechanical adequacy of the fusion mass. Three out of the four (cases 2-4) had their implants removed between 12 and 15 months after the index surgery. All their histological cuts showed evidence of newly formed bone and presence of active membranous and/or enchondral ossification foci. The last patient (case 1) underwent implant removal at 20 months and his histological cuts showed mature bone, but no active ossification foci. This four-case report suggests that the fusion mass produced by a mineralized collagen matrix graft soaked in aspirated bone marrow is histologically and mechanically adequate in a thoracolumbar fracture model. A larger patient series and/or randomized controlled studies are warranted to confirm these initial results.