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.     

A biomechanical evaluation of graft loading characteristics for anterior cervical discectomy and fusion. A comparison of traditional and reverse grafting techniques

STUDY DESIGN: A biomechanical study of graft loading characteristics for anterior cervical discectomy and fusion comparing the amount and location of transmitted forces. OBJECTIVES: To evaluate the difference between traditional iliac grafting and reverse iliac grafting used for anterior cervical discectomy and fusion in the amount and location of forces applied to the grafts. SUMMARY OF BACKGROUND DATA: Traditional fusion after anterior cervical discectomy involves placing a tricortical iliac crest strut into the disc space with the cortical portion facing anteriorly and the cancellous portion posteriorly. Recently, reverse iliac grafting has been introduced in which the cortical portion is placed in the posterior disc space and the cancellous portion in the anterior disc space. There is no biomechanical or clinical study showing an advantage of using one technique over the other. This study is the first to produce data supporting one technique as biomechanically superior. METHODS: Five fresh cadaveric cervical spines were tested using pressure-sensitive film placed between the bone graft and the vertebral endplate after an anterior discectomy was performed. A 10-pound load was applied to the cervical spine at predetermined sagittal positions. Recordings were made at neutral, 10 degrees of flexion, and 10 degrees and 20 degrees of extension after traditional and reverse iliac grafting. RESULTS: Graft forces were identical in both traditional and reverse grafting in the location and amount of force applied. Total force increased to the maximum in flexion and gradually decreased in more extended positions. The location of the forces was completely anterior with flexion, moving to the posterior portion of the graft with positions of extension. With 10 degrees of flexion, the load applied to the grafts was 20.4 N. In the neutral position, the load was 12 N. The loads decreased further with extension with forces of 11 N in 10 degrees extension, and 4 N in 20 degrees of extension. CONCLUSIONS: The optimal position of the tricortical iliac graft for an anterior cervical fusion is with the stronger cortical portion placed in the anterior disc space and the weaker cancellous portion placed in the posterior disc space. In this traditional position, the graft will best resist the loads applied to the cervical spine, preventing graft collapse.     

Ethylene oxide-protein adduct formation in humans: influence of glutathione-S-transferase polymorphisms

Autogenous cancellous bone fragments can be compressed rapidly during surgery to create reproducible load-bearing grafts. Of the 32 grafts tested, 10 were constructed of composite cortical-cancellous bovine bone and 22 of cancellous human bone. Compressed composite bovine grafts and compressed human cancellous grafts supported average axial compressive loads of 2148 N and 960 N, respectively. Compared to iliac crest grafts, compression grafts may have better load-bearing capabilities and greater reproducibility. Potential applications include trauma, delayed unions, arthrodesis, and spinal fusions.     

Reharvest of iliac crest donor site cancellous bone

Patients requiring cancellous bone grafting of an extensive deficit or multiple bone grafting procedures often lack a sufficient quantity of autogenous cancellous bone. Canine studies have indicated that a potential exists for reharvesting autogenous cancellous bone from an iliac crest donor site using a trapdoor harvesting technique. However, significant human experience with this procedure has been lacking. This report describes four patients who underwent successful reharvesting of an iliac crest donor site that provided clinically sufficient autogenous cancellous bone graft material to treat an ongoing or a new skeletal problem. These patients all met specific criteria regarding use of the trapdoor method of bone graft harvest and a minimum 24-month interval between bone grafting procedures. Preoperative computed tomography scanning of the iliac crest was useful in documenting that sufficient cancellous bone was available for reharvest. It appears that iliac crest donor site reharvesting is a specific advantage of the trapdoor technique and is a possible alternative to multiple site grafting or the use of allograft or bone substitute materials.     

A comparison of vascularized and nonvascularized bone grafts for reconstruction of mandibular continuity defects

PURPOSE: This study compared vascularized and nonvascularized bone grafts for the reconstruction of segmental defects of the mandible. PATIENTS AND METHODS: The results in 39 patients having vascularized bone grafts (38 fibulas and one iliac crest) and 29 patients having nonvascularized bone grafts (26 iliac crest [22 corticocancellous block grafts, four cancellous bone grafts in a tray] and three rib grafts) for segmental mandibular reconstruction were evaluated in terms of overall success rate, total number of surgeries performed, total blood loss, total number of hospital days, and total number of hours in the operating room. RESULTS: Of 39 vascularized bone grafts, two failed (95% success rate), whereas of 29 nonvascularized bone grafts, seven failed (76% success rate). Failure for the nonvascularized bone grafts was closely correlated to the length of the defect. Nonvascularized bone graft patients underwent an average of one more surgical procedure for total reconstruction than vascularized bone graft patients, including osseointegrated implants. However, vascularized bone graft patients spent a mean of over 14 additional days in the hospital for all of their reconstructive procedures and an additional 3 hours in the operating room as compared with nonvascularized bone graft patients. Blood loss was similar in both groups (1,100 mL). Only 20% to 24% of patients in each treatment group have completed reconstruction to include osseointegrated implants. CONCLUSIONS: The success rate for vascularized bone grafting is high and is the treatment of choice when primary reconstruction is required, when the patient has been previously irradiated, or when simultaneous replacement of soft tissue is required. Vascularized bone grafts are also the treatment of choice for mandibular replacements over 9 cm in length. Nonvascularized bone grafts create a better contour and bone volume for facial esthetics and subsequent implant insertion, and may be the treatment of choice for secondary reconstruction of defects less than 9 cm in length.     

Prospective evaluation of morbidity associated with iliac crest harvest for alveolar cleft grafting

PURPOSE: This study prospectively evaluated the morbidity associated with iliac crest bone harvest when performed for alveolar cleft grafting. PATIENTS AND METHODS: Twenty-two consecutive patients who underwent an alveolar cleft graft with iliac crest bone harvest were evaluated. The estimated blood loss, length of hip incision, and volume of bone that was harvested were recorded. The duration of time until postoperative ambulation and the length of hospitalization were measured. RESULTS: All patients tolerated the iliac harvest without major complication, and the volume of bone was sufficient in all but one case. Postoperatively, ambulation occurred at an average of 3 hours 18 minutes. Twenty-one patients were discharged the day after surgery; one patient had the surgery performed as an outpatient. CONCLUSIONS: Harvesting cancellous bone from the iliac crest does not result in delayed ambulation or prolonged hospitalization. The morbidity that has been reported to occur with iliac crest bone harvest was not consistent with the results of this study.     

In times of survival, the right of silence

The purpose of this study was to assess cortical and cancellous bone responses to unilateral limb immobilization and, subsequently, to remobilization with exercise, in a young adult canine model. Right forelimbs of 14 1-2-year old mongrel dogs were immobilized in a non-weight-bearing position by a bandage for 16 weeks. Six control dogs were untreated. At 16 weeks, seven immobilized and three control dogs were euthanized. The remaining seven immobilized dogs began a recovery protocol consisting of 16 weeks of kennel confinement (without the right forelimb bandaged) followed by 16 weeks of treadmill exercise conducted three times per week. These seven dogs and three control dogs were euthanized at 48 weeks. Bone mineral density of the proximal radii was determined with dual-energy X-ray absorptiometry and humeral middiaphyseal cross-sectional areas were determined with computed tomography. Humeri were tested in cranio-caudal three-point bending to failure. Cancellous bone cores from the lateral humeral condyles had wet apparent density determined and were tested to failure in compression. Mechanical properties, bone density, and cross-sectional areas were compared between immobilized (right forelimb), contralateral weight bearing (left forelimb), and control forelimbs with Kruskal-Wallis and post hoc tests. At 16 weeks, bone mineral density, cortical load, yield, and stiffness as well as cancellous bone failure stress, yield stress, and modulus were significantly lower (p < 0.02) for immobilized limbs than control limbs. Immobilized limb cancellous bone mechanical properties were 28%-74% of control values, and cortical bone mechanical properties were 71%-98% of control values. After 32 weeks of remobilization, cortical and cancellous bone mechanical properties were not different from control values except that cortical bone failure stress and modulus were significantly higher (p < 0.01) between remobilized and control limbs. In summary, 16 weeks of forelimb immobilization was associated with significantly lower mechanical properties, and with greater differences in cancellous than cortical bone properties. Mechanical properties were not different from control values after 32 weeks of recovery that included 16 weeks of treadmill exercise.     

"Saturday night fever": ecstasy related problems in a London accident and emergency department

Reported sites for retrieval of cancellous bone for grafts include the iliac crest, greater trochanter, proximal tibia, and distal tibia. A new lateral technique for retrieval of cancellous bone from the calcaneus is evaluated through anatomic review, quantitative analysis, and retrospective clinical assessment. Of 22 patients managed with this technique over a 2-year period, 17 returned for an evaluation by questionnaire, physical examination, and radiographic follow-up at an average of 7 months after surgery (range, 4-16 months). Complaints/complications were minor: three had minor incisional symptoms, five had medial heel pain (3 caused by plantar fasciitis), and one had unchanged preoperative heel pain secondary to clubfoot deformity. Compared with more extensive bone-grafting procedures, this procedure offers the advantages of bone harvested under local anesthesia using a readily accessible ipsilateral extremity and producing minor complications.     

Changes in the aortic endothelium and plasma von Willebrand factor levels during the onset and progression of insulin-dependent diabetes in BB rats

The superior volume maintenance of membranous over endochondral bone has been shown in several studies and provides the basis for its preferred clinical use as an onlay grafting material in the craniofacial skeleton. The scientific rationale for this seeming embryologic advantage, however, has never been proven. Our hypothesis is that the pattern of onlay bone graft resorption is primarily determined by a graft's micro-architecture (relative cortical and cancellous composition) rather than its embryologic origin (membranous versus endochondral). Twenty-five adult New Zealand, White rabbits were used for this study. Eight animals were killed at 3 weeks, eight animals at 8 weeks, and nine animals at 16 weeks. Three graft types were placed onto each rabbit cranium: cortical bone graft of membranous origin and cortical and cancellous bone graft of endochondral origin. Fluorochrome markers were injected into all living rabbits at 1, 6, and 14 weeks. Microcomputed tomography scanning was performed on all of the bone grafts to determine postsacrifice volumes and to obtain detailed information regarding the bone graft's trabecular architecture. In addition, specimens were examined histologically. Volume analysis showed a statistically greater resorption rate in the cancellous endochondral bone graft than in either the endochondral or membranous cortical bone grafts (p < 0.05) for all time points. In addition there was no significant difference in the resorption rates between the endochondral and membranous cortical bone grafts. A post-test power analysis (alpha = 5 percent) of the volume data comparing the two types of cortical bone grafts showed that a difference in resorption of 8.9 percent would be detected with a 90-percent probability. Previous studies, which have shown a seeming superiority of membranous over endochondral bone grafts, used composite grafts composed of both cortical and cancellous portions. By separating these components, we have shown that cortical bone grafts maintain their volumes significantly better than cancellous bone grafts. In addition, we found no statistical difference in the resorption rates between the two cortical onlay bone grafts of different embryologic origins, a finding that has never been previously published. From our results, we believe cortical bone to be a superior onlay grafting material, independent of its embryologic origin. We believe these results challenge the currently accepted theories of bone graft dynamics and may lead to a change in the way clinicians approach bone graft selections for craniofacial surgery.     

Possibilities in the reconstruction of bone defects

The importance of the functional unit "bone-soft-tissue" for the treatment of bone defects is discussed. A division is made between non-vascular and vascular bone transport. The individual methods are explained and their clinical significance is illustrated partly using case material. In general, the best way to fill small defects in vital soft tissue is to use cancellous autografts. For bridging longer bone defects callus distraction is the method of first choice, but in individual cases vascularized bone transfer can be taken from the iliac crest or the fibula. Homo- or heterografts should only be used in cases where no autologic bone material is available or when there is not enough.     

Concentration of insulin-like growth factor (IGF)-I and -II in iliac crest bone matrix from pre- and postmenopausal women: relationship to age, menopause, bone turnover, bone volume, and circulating IGFs

Insulin-like growth factor-I (IGF-I) and -II are important local regulators of bone metabolism, but their role as determinants of human bone mass is still unclear. In the present study, we analyzed the concentration of IGF-I and -II in the bone matrix of 533 human biopsies from the iliac crest that were obtained during surgery for early breast cancer. There was an inverse association of bone matrix IGF-I concentration with age that was unaffected by menopause. Bone matrix IGF-I was positively associated with histomorphometric and biochemical parameters of bone formation and bone resorption and with cancellous bone volume. Based on the estimates of the linear regression analysis, women with a bone matrix IGF-I concentration 2 SD above the mean had a 20% higher bone volume than women with a bone matrix IGF-I concentration 2 SD below the mean. In contrast, serum IGF-I was neither correlated with bone turnover nor with bone volume and was only weakly associated with bone matrix IGF-I when adjusted for the serum concentration of IGF binding protein-3. Bone matrix IGF-II was positively associated with the osteoblast surface, but in contrast to IGF-I, tended to be positively associated with age and was unrelated to cancellous bone volume. In summary, our study suggests the following. 1) The concentration of IGF-I in cancellous bone undergoes age-related decreases that are similar to those of circulating IGF-I. 2) Menopause has no effect on this age-related decline. 3) Physiological differences in bone matrix IGF-I are associated with differences in iliac crest cancellous bone volume. 4) Bone matrix IGF-I is a better predictor of cancellous bone volume than circulating IGF-I. 5) The role of IGF-II in human bone tissue is clearly distinct from that of IGF-I.     

Differential giant cell epulis diagnosis--malignant melanoma of the mouth mucosa]

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.     

Mineralized bone loss at different sites in dialysis patients: implications for prevention

To characterize the magnitude and location of mineralized bone loss, 40 patients (20 men, 20 women, 29 white, 11 black) with clinically significant renal osteodystrophy who could be unambiguously classified based on histologic criteria as having osteitis fibrosa (OF; 20 cases) or osteomalacia (OM; 20 cases) were studied; they had been on maintenance hemodialysis for 4.6 +/- 3.0 yr. One hundred forty-two healthy women of similar age and ethnic composition served as control subjects. In all subjects, the proportions of mineralized bone, osteoid, and porosity (nonbone soft tissue) were measured separately in cortical and cancellous bone tissue, from intact full-thickness biopsies of the ilium, representative of the axial skeleton. The results were related to the volumes of cortical and cancellous bone tissue separately and to the volume of the entire biopsy core. Approximately three-quarters of the patients had measurements in the appendicular skeleton by single photon absorptiometry of the radius and morphometry of the metacarpal. Disease effects did not differ significantly between ethnic groups. Mineralized cortical bone volume (per unit of core volume) was reduced by approximately 45% in both patient groups. Mineralized cancellous bone volume was significantly increased by 36% in the patients with OF and nonsignificantly reduced by 9% in the patients with OM; however, the reduction in the latter patients was significant in relation to tissue volume. The combined total deficit for both types of iliac bone was approximately 20% in the patients with OF and approximately 40% in the patients with OM. Significant reductions in appendicular cortical bone were demonstrated in both patient groups at both measurement sites. Regardless of the current histologic classification, the major structural abnormality in the skeleton is generalized thinning of cortical bone due to increased net endocortical resorption, the most characteristic effect on bone of hyperparathyroidism. Protection of the skeleton from the adverse consequences of renal failure will require therapeutic intervention in patients with no symptoms of either renal or bone disease.     

Autogenous iliac crest bone graft. Complications and functional assessment

Functional outcomes and complications experienced by adult patients who underwent iliac crest bone grafting were evaluated to assess the effect of bone grafts on patient function. In addition to retrospective chart reviews, patients completed the Sickness Impact Profile and a detailed questionnaire on pain. One hundred ninety-two patients met study inclusion criteria. Major complications were recorded in four (2.4%) patients in whom infections developed requiring readmission. Thirty-seven (21.8%) patients had minor complications. One hundred nineteen of 170 patients were available for followup; of these 119 patients, 87 (73.1%) returned completed questionnaires. Thirty-three of 87 (37.9%) patients reported pain 6 months postoperatively. The incidence of pain decreased with time, with 16 of 87 (18.7%) patients continuing to report pain more than 2 years postoperatively. Proportionately more spine patients reported pain at all time points. The mean Sickness Impact Profile score for patients completing questionnaires was nine, suggesting most patients were functioning well 2 years postoperatively. The morbidity of iliac crest grafting remains substantial. Pain symptoms in this study sample seemed to last longer in more patients than earlier series have indicated. Minimizing muscle dissection around donor sites and the advent of bone graft substitutes may help alleviate these problems.     

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.     

Spine deformity index in osteoporotic women: relations to forearm and vertebral bone mineral measurements and to iliac crest ash density

Bone densitometric measurements are widely used for monitoring therapeutic regimens for osteoporosis. However, it is a matter of debate which measurement site is most appropriate for prediction of individual fracture risk. The aim of this cross-sectional study was to investigate the relationship between bone mineral measurements at various sites and spine deformity index (SDI) in osteoporotic women. The SDI was determined in 37 osteoporotic women aged 56-87 years (mean 70.9 years). Peripheral (single-photon absorptiometry of the distal forearm, and iliac crest ash content) and axial (dual-photon absorptiometry of the lumbar spine) bone mass measurements were obtained. SDI increased with age (r = 0.34, p < 0.05), whereas forearm BMC (r = -0.52, p < 0.002) and forearm BMD (r = -0.62, p < 0.0001) decreased. No significant age-related changes were observed in lumbar BMC or iliac crest ash content in these osteoporotic women. A highly significant correlation was found between SDI and lumbar BMC (r = -0.60, p < 0.01). A significant, but less pronounced correlation was found between SDI and forearm BMC (r = -0.37, p < 0.05), whereas no relation was revealed between SDI and forearm BMD or iliac crest ash content. In a multiple regression model, the relationship between lumbar BMC and SDI remained significant after adjusting for the influence of age, whereas the relationship to forearm BMC disappeared. Furthermore, a multiple regression analysis was performed in order to evaluate the ability of all four bone mass measurements and age to predict variations in SDI.(ABSTRACT TRUNCATED AT 250 WORDS)     

Complications of spongiosa harvesting of the ilial crest. A retrospective analysis of 1,191 cases

We analyzed retrospectively 1191 cases of bone graft harvesting of the iliac crest which had been performed at our hospital between 1982 and 1991. There was an operative revision rate of 2.8%. For further study, we analyzed the clinical reports of all autograft (iliac crest) donors in a representative year (1991) and re-examined all those who still had symptoms. A total of 104 grafts were taken from 97 patients. Of these, 18 developed postoperative complications (19.6%), such as hematoma, which could usually be treated with local procedures such as aspiration. The rate of hematoma tended to be lower in those patients who had received a local coagulant, but this was not significant. Of the patients 55% still had problems 1 year after operation at the time of re-examination, but in most cases they were minor, for example, local irritation or discomfort. Serious problems developed in those patients who had a palpable defect of the iliac crest. We advise using local coagulants to decrease the rate of postoperative complications, although we cannot statistically prove the effect. When large grafts are harvested, the iliac crest should be reconstructed for better long-term results.     

Reconstruction of the jaw and oral cavity with free vascularized grafts

59 microvascular graft transfers performed in 50 patients in our department since 1985 have been studied retrospectively. The indications for microvascular reconstruction were sequelae after tumour surgery in 38 patients, gunshot injury in seven, chronic osteomyelitis of the mandible in three, complication after jaw fracture in one patient, and atrophy of the alveolar ridge also in one patient. Transplants from the iliac crest, fibula, radius, radial forearm skin and jejunum were used. Three transplants were lost because of arterial thrombosis, giving a success rate of 94.9%. Complications were registered in 19 cases, the largest group being wound infections. 21 of the 50 patients have been treated with dental implants for total rehabilitation of masticatory function. Transfer of free vascularized bone and soft tissue grafts has greatly improved the functional and cosmetic results obtained in reconstructive surgery of the orofacial region.     

Long-term effects of pentobarbital anesthesia on the atrial natriuretic peptide system in rats

The midline fascial splitting approach is a modified midline approach to the iliac crest for bone graft that takes advantage of the anatomic planes between layers of the dorsal lumbar fascia. Two hundred consecutive grafts were taken by this technique with one superficial infection, two cases of serous hematoma, and three patients with significant postoperative pain at the harvest site, for an overall complication rate of 3%. In comparison, bone grafts were harvested from 200 consecutive patients by the midline subcutaneous approach to the iliac crest with 2 deep infections, 1 cluneal nerve injury, 15 patients with severe and disabling pain at the harvest site, and 12 patients with a serous hematoma, for an overall complication rate of 15%. The midline fascial splitting approach significantly reduced the incidence of postoperative serous hematoma (P < 0.007) as well as the incidence of significant and disabling pain (P < 0.001). In addition, the approach is simple, straightforward, anatomic, and decreases trauma to soft tissues.     

Occipital calvarial bone graft in posterior occipitocervical fusion

STUDY DESIGN: Dorsal occipitocervical fusion is associated with a high rate of fusion failure and requires an additional surgical site for donor bone graft harvesting. In this series, an autologous occipital calvarial bone graft obtained from the same occipitocervical incision with contoured metal loops was used in 25 adults to achieve craniovertebral stabilization and fusion. OBJECTIVES: To study the use of autologous occipital calvarial bone grafts in occipitocervical fusion. SUMMARY OF BACKGROUND DATA: Cranial bone grafts have been used successfully in craniofacial reconstruction with good long-term results. In the plastic surgery literature, there are claims that membranous bone grafts are superior to endochondral bone grafts in fusions because of decreased resorption. In recent studies, results have shown successful use of calvarial bone in fusing the upper cervical spine in children. The use of autologous occipital bone in posterior occipitocervical fusions avoids many of the problems associated with traditional donor sites and provides a sufficient quantity of good quality bone for the fusion. This is especially true in the fragile rheumatoid arthritis patient with cranial cervical instability. METHOD: Split-thickness, autologous calvarial bone grafts with contoured loop and cable instrumentation were used for posterior occipitocervical stabilization and fusion in 25 patients, most of whom had rheumatoid arthritis. The calvarial bone graft was harvested from the occipital skull, using a microair impactor, and was secured next to the loop construct. After surgery, all patients were immobilized with external orthoses. RESULTS: None of the patients had hardware failure or complications from the occipital graft procurement. In 22 patients, good alignment, stability, and bony fusion were shown on radiographs. CONCLUSIONS: Occipital calvarial bone graft appears to work as well as other autologous corticocancellous bone grafts routinely used in posterior occipitocervical fusions.