Split calvarial graft cranioplasty for the prevention of headache after retrosigmoid resection of acoustic neuromas

OBJECTIVE: This study describes the technique and efficacy of split calvarial graft cranioplasty for the reconstruction of retrosigmoid/suboccipital defects following surgery for acoustic neuromas. STUDY DESIGN: A prospective study of the technique of split calvarial graft cranioplasty, its postoperative healing, and incidence of postoperative headache. METHODS: The technique requires splitting of the craniotomy bone flap into outer and inner table bone grafts. The combination of both bony grafts allows the coverage of a wider area of posterior fossa dura. This technique was used in 18 patients. All patients were followed for a minimum of 6 months. Eleven of 18 patients were followed for 1 year or longer. Four patients had three-dimensional computed tomography of their skull and area of split calvarial bone graft. RESULTS: One of 18 patients had a persistent disabling headache at 1 year postoperatively. A natural contour of the retrosigmoid area was achieved in all patients. Three-dimensional computed tomography scan, obtained 6 months postoperatively, showed total coverage of the retrosigmoid area and fusion of the bone flap to the surrounding skull. CONCLUSION: The technique of split calvarial grafting of posterior fossa defects is a feasible, safe, and effective way of separating the nuchal musculature and posterior fossa dura. The technique also allows the restoration of the contour and bony covering of the retrosigmoid area. The technique is a simple alternative to other types of cranioplasties aimed at reducing the incidence of postoperative headache in patients with acoustic neuromas.     

Occipitocervical fusion with a five-millimeter malleable rod and segmental fixation

Although occipitocervical fusion is frequently used for instability of the upper cervical spine and the occipitocervical articulation, most currently used techniques have one or more of the following disadvantages: the necessity for sublaminar wires, the use of occipital screws, a fixed angle of instrumentation, or the necessity for routine postoperative halo immobilization. Moreover, many reported techniques are associated with a high rate of nonunion or instrumentation failure. We present our experience with a technically simple method of obtaining rigid occipitocervical arthrodesis using a 5-mm malleable rod that is fixed to the skull by a pair of wires passed through four suboccipital burr holes. Segmental spinal fixation is achieved with Wisconsin interspinous wires and is occasionally supplemented with sublaminar wires. Supplemental autogenous bone graft is used in all cases. A cervical collar is routinely used for postoperative immobilization. The results of treatment were retrospectively reviewed in 16 patients with an average age of 49.4 years (range, 9-69). Mean follow-up was 24 months (range, 12-36 mo). The indication for fusion was instability of the occiput-C1-C2 complex as a result of Chiari malformation, rheumatoid disease, skull base tumor resection, basilar invagination, ankylosing spondylitis, Down's syndrome, cervical laminectomy, and trauma. The average number of levels fused was 5.4 (range, O-C3 to O-T3). Successful occipitocervical arthrodesis was achieved in all but one of the surviving patients. The single patient with a pseudarthrosis was successfully managed with supplemental bone grafting and halo immobilization. There were two deaths from medical complications in chronically ill patients. Other complications included one postoperative instrumentation loosening, one myocardial infarction, and one superficial occipital decubitus. In conclusion, rodding and segmental interspinous wiring is an effective, technically simple method of obtaining rigid occipitocervical fixation, which obviates the need for bulky orthoses.     

3- to 11-year followup of occipitocervical fusion for rheumatoid arthritis

The relief of myelopathy usually is unsatisfactory by a conventional Gallie type atlantoaxial fusion for patients with rheumatoid arthritis who have irreducible atlantoaxial dislocation. To accomplish a decompressive laminectomy of the atlas in the treatment of myelopathy, the authors have been performing a new surgical procedure since 1985 for occipitocervical fusion using a rectangular rod. The postoperative outcomes for 25 patients with rheumatoid arthritis were evaluated clinically and radiographically with a 3- to 11-year (mean, 6.5 years) followup. A decompressive laminectomy of the atlas accompanied the fusion in 21 of the 25 patients. The incidence of occipital or nuchal pains improved notably in most cases, and myelopathy was relieved in 12 of 18 (67%) cases, showing an improvement of more than one level based on Ranawat's criteria. No serious postoperative complications were seen, except for one case of a failed bone union. The cumulative survival in patients with myelopathy was 79.4% in the first 5 years after operation and 27.5% at 10 years. Occipitocervical fusion using a rectangular rod accompanied by a decompressive laminectomy of the atlas can contribute to the relief of a neurologic deficit in an irreducible atlantoaxial dislocation in rheumatoid arthritis.     

Bovine bone grafting in occipito-cervical fusion for atlanto-axial instability in rheumatoid arthritis

Bovine bone chips (Surgibone) were used in occipito-cervical fusion in nine patients with atlanto-axial instability due to rheumatoid arthritis. The patients were examined with CT 12-15 months after surgery. Graft resorbtion was observed in one patient. The other 8 patients showed preserved grafts, in most cases the grafts appeared to be in contact with the underlying bone. One patient was revised, and at the grafted site a bony bridge was found. In conclusion, the use of bovine chips in posterior occipito-cervical fusion will not lead to predictable bone union. However, there seem to be exceptions to that rule.     

Posterior C1-C2 transarticular screw fixation for atlantoaxial arthrodesis

OBJECTIVE: To assess the outcomes associated with C1-C2 transarticular screw fixation. METHODS: The clinical outcomes of 121 patients treated with posterior C1-C2 transarticular screws and wired posterior C1-C2 autologous bone struts were evaluated prospectively. Atlantoaxial instability was caused by rheumatoid arthritis in 48 patients, C1 or C2 fractures in 45, transverse ligament disruption in 11, os odontoideum in 9, tumors in 6, and infection in 2. RESULTS: Altogether, 226 screws were placed under lateral fluoroscopic guidance. Bilateral C1-C2 screws were placed in 105 patients; each of 16 patients had only one screw placed because of an anomalous vertebral artery (n = 13) or other pathological abnormality. Postoperatively, each patient underwent radiography and computed tomography to assess the position of the screw and healing. Most screws (221 screws, 98%) were positioned satisfactorily. Five screws were malpositioned (2%), but none were associated with clinical sequelae. Four malpositioned screws were reoperated on (one was repositioned, and three were removed). No patients had neurological complications, strokes, or transient ischemic attacks. Long-term follow-up (mean, 22 mo) of 114 patients demonstrated a 98% fusion rate. Two nonunions (2%) required occipitocervical fixation. In comparison, our C1-C2 fixations with wires and autograft (n = 74) had an 86% union rate. CONCLUSION: Rigidly fixating C1-C2 instability with transarticular screws was associated with a significantly higher fusion rate than that achieved using wired grafts alone. The risk of screw malpositioning and catastrophic vascular or neural injury is small and can be minimized by assessing the position of the foramen transversaria on preoperative computed tomographic scans and by using intraoperative fluoroscopy and frameless stereotaxy to guide the screw trajectory.     

Prognostic factors and therapeutic options of radiotherapy in pediatric brain stem gliomas

BACKGROUND: Calvarial bone graft is often used in reconstructive cranio-facial surgery. As most common three different forms can be distinguished: outer-table bone, full thickness grafts and composite flaps (bone with a periostal or muscular pedicle). PATIENT AND METHOD: An extensive fibrous dysplasia of the frontal region was removed in a 26 years old patient. Reconstruction was carried out with alloplastic material achieving a good esthetic result. Recurrent seroma and occurrence of a fistula demanded removal of the alloplastic material and en-bloc reconstruction of the forehead region was accomplished with a parietal outer-table graft. Within a follow-up time of one year a good esthetic and stable reconstruction has been achieved. CONCLUSION: Split-thickness calvarial bone is still a versatile graft in reconstruction of the forehead region. Although a low rate of side effects in harvesting calvarial bone grafts are in general expected, one has to be aware of dural lesions occuring in the donor site during craniotomy.     

Surgery of the upper cervical spine in rheumatoid arthritis. Indications and results apropos of 28 cases

PURPOSE OF THE STUDY: The goal of this study was to precise indications and surgical techniques for stabilisation with or without decompression of the upper cervical spine instability in rheumatoid arthritis. MATERIAL AND METHODS: 28 patients presenting upper cervical spine disease have been reviewed (mean age 57 years). These patients had been suffering from severe diffuse arthritis during an average of 14.5 years. The anterior atlanto-axial dislocation was most frequent (25 times), 1 posterior dislocation and 2 vertical dislocations. Odontoid lysis was noted 19 times. A subluxation of the lower cervical spine was present in 12 patients. SURGICAL TECHNIQUE: C1-C2 arthrodesis was performed 12 times (9 times with a loop wire and 3 isthmo-pedicular screws C2-C1), occipito-cervical arthrodesis with plates 16 times. Operative traction was necessary 5 times. The associated surgical gestures included 3 times a laminectomy, 2 times an enlargement of the occipital foramen, 1 section of the Arnold nerve. In 2 patients was associated a fixation of the lower cervical spine. RESULTS: With an average of 27 months follow-up, functional results (classified according to Ranawat's criteria) were satisfactory in 14 patients, improved in 7 patients, unchanged in 4 and bad in 3. The reduction of the anterior displacement in 25 patients was complete 11 times, partial 17 times and null 3 times. The reduction of the vertical displacement was complete once, partial 3 times. Arthrodesis fusion was obtained in 19 cases, 5 times it was a fibrous union and 4 pseudarthrosis occurred, all with C1-C2 loop wire. The rate of complications was high: 2 infections on bone site grafting requiring reoperation, 2 infections with secondary septicemia after lack of reduction. DISCUSSION AND CONCLUSION: Occipito-cervical arthrodesis is necessary as soon as the patient presents neurological signs. When there is an anterior dislocation associated with vertical dislocation, if there is posterior dislocation in case of osteoporosis of the posterior C1-C2 arc, or destabilisation of the lower cervical spine. C1-C2 arthrodesis is suggested when there is no important neurological signs, when displacement is limited to a pure anterior dislocation and in young patient with good bone quality.     

Use of demineralized bone matrix in hindfoot arthrodesis

Fifty-five patients considering a hindfoot fusion performed by the senior author over a 5-year period were given the choice of having the fusion augmented by either iliac crest bone graft or demineralized bone graft in a study of the relative efficacy of these 2 methods of bone grafting. Eleven patients underwent subtalar fusion (average age, 40.1 +/- 14.0 years), and 44 had a triple arthrodesis (average age, 54.6 +/- 19.2 years). The most common indications for surgery were posterior tibial tendon insufficiency and traumatic arthritis. There were no significant differences between groups regarding underlying disease, medications, or associated medical conditions. In isolated subtalar fusions, all 3 patients who received an iliac crest bone graft experienced healing, as did 7 of 8 patients who received demineralized bone graft. The eighth patient had a radiographic non-union without clinical symptoms. Complete healing of triple arthrodeses was achieved in 13 of 15 patients who received an iliac crest bone graft and in 29 of 29 patients receiving a demineralized bone graft. There were no intergroup differences in the time to union, which generally was between 3 and 4 months. Intraoperative blood loss was significantly less with demineralized bone graft (33 +/- 25 ml) than with iliac crest bone graft (206 +/- 192 ml). This study demonstrated that demineralized bone graft aids arthrodesis at least as well as does iliac crest bone graft, without the increased blood loss, cost, and postoperative pain associated with iliac crest bone harvest.     

In vivo evaluation of recombinant human osteogenic protein (rhOP-1) implants as a bone graft substitute for spinal fusions

STUDY DESIGN: Posterior spinal fusion segments were evaluated in adult mongrel dogs at 6, 12, and 26 weeks post-implantation. Four sites on each animal received implants consisting of recombinant human osteogenic protein-1 on a bone collagen carrier, bone collagen carrier alone, autogenous iliac crest bone, or no implant material. OBJECTIVE: To determine the efficacy of recombinant human osteogenic protein-1 as a bone graft substitute in achieving posterior spinal fusion and compare the results to those obtained using autogenous bone graft. SUMMARY OF BACKGROUND DATA: Posterior spinal fusion generally includes onlay grafting of autogenous or allogeneic bone after decortication of bony surfaces of the vertebral elements. The search for an acceptable bone graft substitute material has in recent years centered upon proteins capable of inducing bone in vivo. Recombinant human osteogenic protein-1 has demonstrated efficacy in healing large segmental osteoperiosteal defects in rabbits, dogs, and monkeys and appears ideally suited as a bone graft substitute for spinal fusions. METHODS: The quality of fusion and new bone formation was evaluated using plain films, computed tomography, and magnetic resonance imaging. RESULTS: Radiographic and histologic studies demonstrated that recombinant human osteogenic protein-1-treated fusion segments attained a stable fusion by 6 weeks post-implantation and were completely fused by 12 weeks. The autograft sites demonstrated fusion at 26 weeks post-implantation. CONCLUSIONS: The results indicated that recombinant human osteogenic protein-1 is an effective bone graft substitute for achieving stable posterior spinal fusions in a significantly more rapid fashion than can be achieved with autogenous bone graft.     

Occipitocervical fixation using hooks and screws for upper cervical instability

OBJECTIVES: Occipitocervical fixation is used for the treatment of nontraumatic upper cervical instabilities. To date, plates have been fixed with screws or wires. However, these devices are not indicated in the treatment of patients with severe osteoporosis or in instances of significant thinning of the occipital bone. We performed a clinical trial of a new type of fixation that uses cervical interlaminar hooks and occipital claws with hooks or with screws (CCD type; Sofamor-Danek, Roissy, France) for the treatment of nontraumatic upper cervical instabilities. METHODS: Five women and one man ranging in age from 28 to 72 years (average age, 54 yr) were thus treated. The CCD type material had two rod plates and hooks allowing the proper placement of interlaminar and occipital claws. The occipital plate can also be directly screwed to the bone. Occipital hooks were used in four patients. The other two patients, who had occipitocervical congenital abnormalities that required an occipitocervical opening and an additional dural enlargement, underwent occipital screw fixation because of the previous opening of the foramen magnum. A cancellous iliac autograft allowed the usual fusion. RESULTS: No postoperative complications were observed, and all patients experienced significant improvement of their neck pain. Four patients had neurological symptoms. The condition of two patients improved, and the condition of the other two stabilized. CONCLUSION: This report confirms the interest of the CCD method to correct all types of upper cervical instabilities, even in cases of unusual thinning of the occipital bone or in osteoporotic states.     

Counterflow centrifugal elutriation: present and future

Only single cases with rheumatoid arthritis of the thoracic spine with vertebral subluxation have been reported to date. In a review of 100 patients with severe rheumatoid arthritis who had undergone occipitocervical fusion, arthritis of the upper thoracic spine with subluxation was discovered on conventional radiographs in four patients. Two additional patients were found elsewhere. Magnetic resonance imaging (MRI) was performed in three of the patients, confirming the diagnosis of subluxation of the upper thoracic vertebrae. In addition, MRI revealed encroachment on the anterior subarachnoid space and compression of the spinal cord.     

Implementation of new technologies in cytotechnology education

INTRODUCTION: Current cranioplasty materials include autologous or homologous bone grafts, wire mesh and methyl methacrylate, either alone or in combination. However, each material has its own unique disadvantages. Although hydroxyapatite has been used extensively in other specialties as a bone substitute, the coralline form has rarely been used to repair cranial bone defects. Coralline hydroxyapatite, similar to that found in bone, provides a matrix on which living tissue can form and grow. Because it is an ideal bioimplant, a method of cranioplasty using coralline hydroxyapatite was employed. METHODS: The hydroxyapatite granules are mixed with Avitene and autologous blood to form a paste which can be contoured as needed. RESULTS: Over the past few years, we have used hydroxyapatite either alone or in combination with tantalum mesh in 19 pediatric patients for a variety of conditions. The cosmetic results were good to excellent. Furthermore, postoperative CT scans have documented bony substitution of the hydroxyapatite granules. Follow-up ranged from 1 to 43 months with a mean of 26 months. CONCLUSION: In neurosurgical procedures when a bone substitute is needed, hydroxyapatite is an effective alternative to other currently available materials.     

Autologous calvarial and iliac onlay bone grafts in miniature swine

Calvarial bone has been reported to be superior to iliac bone for onlay bone grafting due to decreased resorption. This study evaluated the physical, histologic, and radiographic characteristics of calvarial and corticocancellous iliac onlay bone grafts in nine Pitman-Moore miniature swine at 2 weeks, and at 1-, 2-, 4-, 6-, 7-, 8-, 10-, and 12-month intervals. Compared with iliac grafts, the calvarial onlay grafts had more than a twofold greater radiographic density. Statistical analysis of the mature grafts using the standard of estimated means of the bone graft volumes revealed 85% retention of the calvarial grafts compared with 34% retention of the grafted iliac bone. There was no subjective difference in the rate or degree of revascularization between the two grafted materials.     

Occipitocervical fusion with C1 laminectomy in children

STUDY DESIGN: Eight children in whom atlantoaxial dislocation had developed underwent occipitocervical fusion using a rectangular rod. The postoperative results are presented, and the postoperative growth and deformation of the cervical spine were determined radiographically. OBJECTIVES: To investigate in a relatively long-term follow-up study whether occipitocervical fusion affects the growth of the cervical spine and induces spinal deformation. SUMMARY OF BACKGROUND DATA: It has been reported that children who have undergone C1-C2 posterior fusion are likely to develop abnormal curvature or deformation of the cervical spine as a result of a disturbance of growth of the fused vertebrae. There have been no studies, however, to confirm that these changes occur after occipitocervical fusion in children. METHODS: The subjects were one boy and seven girls who had undergone occipitocervical posterior fusion during childhood. The average age at the time of surgery was 8.3 years, and the average follow-up period was 5.9 years. The following were assessed radiographically: redislocation of the atlas, bone union, changes in the curvature of the cervical spine, the height and width of the vertebral bodies, and the anteroposterior diameter of the spinal canal. RESULTS: Solid bone union was achieved in all patients with maintenance of the reduced position at the time of surgery. None of the patients exhibited abnormal curvature of the cervical spine. The rate of increase in height of the C2 vertebral body was significantly less than that of vertebral bodies below C3. The rate of increase in width of the vertebral body and the anteroposterior diameter of the spinal canal of the C2 vertebral body and vertebral bodies below C3 did not differ significantly. CONCLUSIONS: Occipitocervical fusion with a rectangular rod is useful for treating atlantoaxial dislocation in children and yields excellent results because of the firm internal fixation it achieves. This surgery induced no apparent postoperative spinal deformations.     

Wrist arthrodesis for failed wrist implant arthroplasty

Thirteen wrist arthrodeses were performed for failed wrist implant arthroplasties between 1984 and 1992. Twelve patients were available for review, with an average follow-up period of 28 months. The original arthroplasties consisted of 8 silicone implants and 4 metal-plastic total wrist implants. The surgical method involved a tricortical iliac bone graft and an intramedullary Steinmann pin. There were 7 excellent results, 4 good results, and 1 poor result. All but 1 patient had markedly improved function with no or mild pain. Seven patients had solid fusions and 5 patients had pseudarthroses. Four pseudarthroses occurred at the graft-metacarpal junction and 1 occurred at the graft-radius junction. Each patient with a solid fusion had an excellent result. All graft-metacarpal pseudarthroses were painless and did not limit the patients' activities. There were 17 complications in 9 patients. Wrist arthrodesis can be a successful salvage procedure for failed wrist implant arthroplasty in patients with rheumatoid arthritis. However, the complication rate can be high. Owing to the high incidence of distal graft-metacarpal pseudarthrosis, we recommend using more rigid fixation techniques in patients with failed wrist arthroplasties.     

Spontaneous and induced minisatellite instability in the human genome

Two patients with recurrent parotid gland carcinoma required subtotal petrosectomy and infratemporal fossa type C approach. To achieve en bloc resection, the ascending mandibular ramus and the entire temporomandibular joint, including the adjacent temporal bone, were removed. An original technique for immediate reconstruction of the infratemporal region, including the glenoid fossa and the ramus of the mandible, is described. Rigid fixation, as well as good functional and aesthetic results, was achieved with autologous calvarial bone and full-thickness rib grafts, allowing the patients to mobilize their jaw very rapidly.     

Microsurgical anterior decompression and internal fixation with iliac bone graft and titanium plates for treatment of cervical intervertebral disc herniation

42 cervical interbody fusions with iliac bone graft and titanium plate fixation were performed between October 1991 and March 1994. The mean follow up period in this study was 10.7 months. In 32 cases fusion was done for 1 and in 10 cases for 2 segments. 2 different types of plates were used. In 25 cases micro-osteosynthesis plates and screws with 2.7 mm diameter were used, and in 17 cases cervical H-plates and screws with 3.5 mm diameter. A favourable outcome was achieved in 31 of 42 cases (74%). Satisfactory pain relief was achieved in 90%. For radicular motor deficit good results were obtained in 84% and for cervical myelopathy in 54%. The 2 different types of plates showed a remarkable difference in the clinical outcome. The results were regarded favourable in 15 of 25 microplate fusions (60%) and in 16 of 17 H-plate fusions (94%). Compression of the bone graft was seen in 5 patients of the micro plate group, however, radiological signs for fusion were present in all 42 cases at follow up. Major surgical complications, damage to neural structures or neurological deterioration did not occur in this study. Plate fixation in cervical interbody fusions seems to be a safe procedure and may reduce graft related complications at the fusion site if the plates and screws are sufficiently well proportioned. A favourable impact upon the results for cervical interbody fusion might be expected and should be further investigated in a long term follow up study.     

Autologous bone grafting in staged scoliosis surgery. The patient as bone bank

STUDY DESIGN: A prospective clinical study in which autologous rib graft, harvested during the thoracotomy in staged scoliosis correction, is stored within the patient for use during the second stage (posterior intrumentation and fusion). OBJECTIVE: To determine whether the bone stored by this technique is biologically viable and microbiologically safe. SUMMARY OF BACKGROUND DATA: To the authors' knowledge, this method of storage of bone has never been described previously. METHODS: During the first operation, the excised rib was divided into 3-5 cm fragments and stored in a sub-muscular plane adjacent to the posterior elements of the spine before closure. The graft was then retrieved at the second stage. Samples were sent for histologic and microbiologic examination before implantation. RESULTS: On histologic examination, more than 50% of the osteocytes retained their basophilic staining, indicating that they were viable. In addition, osteoclastic activity was notably absent. There was no significant bacterial contamination of the samples. Clinically, all patients achieved satisfactory bone fusion. CONCLUSION: Homeostatic equilibrium in humans provides the ideal environment in which bone graft can be stored. There is no increased risk of infection, and the osteogenic potential of the graft is retained.     

Optimal selection and preparation of fresh frozen corticocancellous allografts for cervical interbody spinal fusion

STUDY DESIGN: Iliac crest corticocancellous allografts for anterior interbody fusion were harvested from six cadavers. The grafts were cut sequentially from left and right crests and randomly assigned to tricortical or bicortical preparations. Their compression strengths then were determined and compared by matched pair analysis. OBJECTIVES: To quantify the failure strength of the grafts from different iliac locations and determine the optimal type of preparation of the grafts for anterior interbody fusion. SUMMARY OF BACKGROUND DATA: Iliac crest corticocancellous autografts and allografts commonly are used for interbody cervical fusions. However, graft strengths for specific sites have not been determined fully. METHODS: Six paired, fresh frozen, iliac crests were sectioned using a customized miter box into multiple 1-cm-thick grafts 1.5 cm in depth to simulate cervical interbody grafts. The left and right sides of each pair were randomly assigned to tricortical and bicortical preparations. The samples were tested by applying a compressive load to failure using a specialized fixture to simulate vertebral body loading. RESULTS: The grafts closer to the anterosuperior iliac spine had significantly higher failure loads and failure strengths than those closer to the posterosuperior iliac spine. The strengths of the bicortical grafts were 72 +/- 14% of the strengths of the tricortical grafts (P < 0.001). CONCLUSIONS: Anterior iliac crest grafts were stronger in compression, even after removal of one cortical surface, than posterior iliac crest grafts.     

Reversing the inhibitory effect of nicotine on spinal fusion using an osteoinductive protein extract

STUDY DESIGN: The effect on spinal fusion of an osteoinductive bone protein extract in the presence of a known inhibitor of spinal fusion (systemic nicotine) was studied prospectively in an animal model of posterolateral lumbar fusion. OBJECTIVES: To evaluate the ability of a bovine-derived osteoinductive bone protein extract to overcome the inhibitory effect of nicotine in a rabbit spine fusion model. SUMMARY OF BACKGROUND DATA: Multiple studies have demonstrated the ability of a variety of osteoinductive growth factors to serve as a bone graft substitute for lumbar spinal fusion under "normal" healing conditions. METHODS: Forty-eight adult female New Zealand white rabbits underwent spine arthrodesis at L5-L6 while receiving systemic nicotine through a subcutaneous miniosmotic pump. Arthrodesis was performed using one of the following three graft materials: 1) autogenous iliac crest, 2) osteoinductive bone protein delivered in an allogeneic demineralized bone matrix/ collagen carrier, or 3) osteoinductive bone protein delivered with autogenous iliac crest. Fusions were assessed by blinded manual palpation, radiography, and biomechanical testing. RESULTS: Of the 44 rabbits manually tested by blinded observers, all 14 in the osteoinductive bone protein plus autogenous iliac crest bone group had solid fusions (14 of 14), whereas the fusion rate was less in the osteoinductive bone protein plus demineralized bone matrix group (nine of 14, 64%; P = 0.02), and there were no fusions in the autogenous iliac crest only group (0 of 16, 0%; P = 0.000001). The use of osteoinductive bone protein with autogenous bone produced stronger and stiffer fusions compared with those using autogenous bone alone or osteoinductive bone protein with allograft bone. CONCLUSIONS: Cigarette smoking and nicotine are inhibitory factors in the healing of fractures and spine fusions. This study shows that the inhibitory effect of nicotine can be overcome with an osteoinductive bone growth factor in an animal model.