J Neurosurg 76:298-302, 1992
Multilevel anterior cervical fusion using skull bone grafts Case report TOKUTARO TANAKA, M.D., TOSHIAKI NINCHOJI, M.D., KENICHI UEMURA, M.D., HmOSHl RYU, M . D , MASASH[ SUGIURA, M.D., HARUYUKl OHISHL M.D.,
MAMORU TOMITA, M.D., SEIYA TAKEHARA, M.D., AND TAKAMICHIYAMAMOTO, M.D. Departments of Neurosurgery, Yaizu Municipal Hospital, Yaizu; Kyoritsu Kikugawa Hospital, Kikugawa; Hamamatsu UniversitySchool of Medicine and Medical Center Hospital Hamamatsu; and Shinshiro MunicipalHospital, Shinshiro, Japan ~" The successful use of autogenous skull bone grafts for a C3-7 anterior cervical fusion is reported and compared with results using other bone grafts. A 5 l-year-old man with C4-7 anterior cord compression due to spurs and ossified posterior longitudinal ligaments developed progressive tetraparesis following a minor head injury. He underwent anterior decompression and fusion. On two occasions an iliac graft had failed; however, a graft of autogenous skull bone was successful. The skull bone was found superior to bone from other sites, such as the iliac crest, rib, tibia, and fibula, showing sufficient strength and less morbidity. The skull may be a better source of graft material for multilevel anterior cervical fusion, which requires long and strong grafts. 9 anterior cervical fusion 9 bone graft posterior longitudinal ligament spondylosis
KEy WORDS
ULTILEVEL anterior cervical decompression and fusion procedures have been widely employed in the treatment of myelopathy due to a long ossified posterior longitudinal ligament and/ or multilevel cervical spondylosis. 2'7'~L~2'~5 Reported sources for bone graft include the iliac crest, rib, tibia, and fibulaY ~~176There are several problems associated with these grafts. A graft from the iliac crest cannot be shaped to the exact size desired, is not strong enough, 4"~~176 and is complicated by hip pain. Rib grafts are not strong, 8 and few have been reported. The donor sites for tibial grafts fracture frequently.~~ Fibular bone is strong enough for grafting, but the triangle-shaped graft in its cross section has exhibited some difficulty in fusing to the resected vertebrae 7'~3~5'16and its donor site shows functional morbidity. 2~ We present a case of successful C3-7 anterior cervical fusion using skull bone grafts and discuss the advantages of this method.
M
Case Report This 51-year-old man was struck on the right forehead in a motorcycle accident on September 21, 1988. He developed motor weakness of both upper extremi298
9 cervical spine
ties and was immediately brought to our neurosurgical service. Examination. Neurological examination on admission showed an acute central cord syndrome, dominant on the left side. He could barely move the left upper extremity against gravity. The muscle strength of the right upper extremity was greater than the left, but also below normal. He showed decreased sensation to pinprick over his neck and both upper extremities. The muscle strength of the lower extremities was normal. Lateral cervical x-ray films showed a segmental ossified posterior longitudinal ligament from C-4 to C-5 and posterior spurs from C-5 to C-7. Conventional and computerized tomography (CT) myelography showed anterior cord compression by the ossified posterior longitudinal ligament and spurs. A dynamic study of neck flexion and extension showed no instability. The patient returned to his previous work 25 days after injury, with instructions to use a Philadelphia collar. About 8 weeks after the injury, the patient developed a slowly progressive left dominant tetraparesis and distally dominant decreased sensation to pinprick over the lower extremities. It was learned that he had seldom worn the neck collar. Magnetic resonance (MR) imagJ. Neurosurg. / Volume 76 / February, 1992
Anterior cervical fusion using skull bone grafts
FIG. 1. Magnetic resonance image showing anterior cord compression extending from C-4 to C-7.
FIG. 3. Schematic drawing of our method of using skull bone grafts for multilevel anterior cervical fusion.
FIG. 2. Cervical x-ray films. Left: Film obtained 3 days after a right iliac crest bone graft showing the first iliac graft fracture (arrow). Right: Film obtained 5 weeks after a left iliac crest bone graft showing the second iliac graft fracture
(arrow).
ing showed multilevel anterior cervical cord compression corresponding to that revealed on a previous CTmyelography study (Fig. 1). Operations. The patient underwent surgery 16 weeks after the injury. The ossified posterior longitudinal ligament and spurs were resected and an anterior cervical fusion from C-3 to C-7 was carried out with a bicortical bone graft from the fight iliac crest. A halo vest was applied immediately. By the next day, the subjective motor weakness and hypesthesia had improved, the left dominant tetraparesis was slightly better, and the decreased sensation to pinprick over the
J. Neurosurg / Volume 76/February, 1992
lower extremities had disappeared except for the soles of the feet. Three days later, however, a lateral cervical x-ray film showed that the grafted bone had fractured (Fig. 2 left). Five days after the first operation, a new and wider bone graft from the left iliac crest was inserted. A halo vest was applied with great care. Two weeks after the second operation, the patient started gait training. Anteroposterior and lateral cervical x-ray films were taken once a week. During the 5th week after surgery, the grafted bone was again found to be fractured (Fig. 2 right). In the third operation, we used skull bone grafts. Our method is shown schematically in Fig. 3. Parasagittal CT sections perpendicular to the skull surface and reconstructed from 1-mm slice axial scans were obtained for measurement. Measurement on the lateral cervical x-ray films showed that new bone grafts must be longer than 60 mm, and measurement from the reconstructed CT scans showed that it was possible to obtain 65-mm grafts posterior to the coronal suture. The patient underwent a third operation on March 20, 1989. Two plates of parasagittal skull were resected and shaped to the exact size. The top and bottom of these plates were notched by drilling to avoid the graft slipping out postoperatively. Cranioplasty with methyl 299
T. Tanaka, et al.
FIG. 4. Cervical x-ray films. Left: Intraoperative film, lateral view, showing the two skull bone grafts in place. The top and bottom of the grafts were notched to avoid postoperative slipping. Right: Postoperative film, anteroposterior view, showingthe two symmetrical skull bone plates inserted back-to-back.
methacrylate was performed concurrently. The grafts were then inserted (Fig. 4) and the gap between the plates was packed with bone dust from the skull. A halo vest was applied immediately. Postoperative Course. The patient's neurological condition was essentially unchanged from that after the first surgery. The postoperative course was uneventful. The halo vest was removed 16 weeks after the third operation under fluoroscopic control to ensure that there was no instability, and a Philadelphia collar was applied. The patient was discharged from the hospital 20 weeks after the third operation, and subsequently returned to his previous work. An MR image obtained 7 months after the third operation showed adequate anterior decompression (Fig. 5 left). A lateral cervical x-ray film obtained 9 months after the third operation showed bone fusion (Fig. 5 right). Two years after the third operation, there was no cervical deformity and the patient was working at full capacity. The latest cervical films and CT scans, taken 20 and 24 months after the last surgery, showed good bone fusion and sufficient anterior decompression (Figs. 6 and 7). Discussion Peripheral Donor Sites The reported sources of bone grafts for multilevel anterior cervical fusion are the iliac crest, rib, tibia, and fibula. 3'7''~176The problems associated with the use of iliae grafts are as follows: 1) the curved iliac crest consists chiefly of cancellous bone with a very thin layer of compact bone on its surface; 2) long grafts from the iliac crest cannot be shaped to the exact size desired and are not strong enough; 3) the donor site often fractures;l,7.11,12,14,2o and 4) painful hip with or without a donor-site fracture is a frequent complication.
300
FIG. 5. Postoperative studies, lateral view. Left: Magnetic resonance image obtained 7 months after the third operation showing adequate anterior decompression. Right: Cervical x-rayfilm obtained 9 months after the third operation showing bone fusion.
A tibial graft is straight and strong, but the donor site frequently fractures. Gore and Sepic '~ reported that, among 107 patients, 15 developed stress fracture at the tibial graft donor site; thereafter, they began to use a fibular graft. Whitecloud and LaRocca2~ have used a fibular strut graft after corticocancellous bone graft fracture. Tomimura, et al., ~s reported that they had abandoned using iliac grafts because long, sturdy grafts had not been available from the ilium and had also ceased obtaining tibial grafts after a donor-site fracture. Recently, many surgeons have come to use a fibular graft for multilevel anterior cervical fusion because straight, strong graft material with enough length can be excised. 3-5'9'~~176 The diaphysis of the fibula consists of pure compact bone and is strong enough, but a fibular graft needs a much longer time to fuse than other grafts. The triangle-shaped fibular graft in its cross section does not easily fuse to the lateral component of the resected vertebrae in the middle portion. Whitecloud and LaRocca2~estimated that a fibular strut bone graft needs approximately 1 year to fuse. Otani, et al., ~3 reported that a 10-cm fibular strut graft needs 2 years to fuse. A free vascularized fibular graft involving microvascular anastomosis has been used recently to obtain early bone fusion; 7'~6.~7 however, the muscle sleeve around the bone inhibits bone fusion in the middle portion 7'~5 and the donor site shows functional morbidity. Youdas, et aL, 2' reported that muscle strength was significantly impaired, especially in foot inversion and eversion. Such functional morbidity should be avoided in patients who might have gait disturbance due to myelopathy. Few rib grafts for anterior cervical fusion have been reported. Freidberg, et al., 8 pointed out that rib bone is not strong even when it is vascularized. Its curve, tubular structure, and the complication of opening the J. Neurosurg. / Volume 76/February, 1992
Anterior cervical fusion using skull bone grafts
FIG. 6. Cervical x-ray films obtained 20 months after the third operation. The flexion (upper left), neutral (upper center), and extension (upper right) postures show good upper bone fusion. The patient's shoulders overshadowed the lower edges of the grafted bone, although his upper extremities were strongly pulled down. The anteroposterior (lower left), fight anterior oblique (lower center), and left anterior oblique (lower right) views show good bone fusion of the lower edges of/he graft.
thorax may also be reasons for the few reports of its use.
Skull as Donor Site The skull bone consists of a thick compact outer table and a less thick inner table, with cancellous bone between them. In our grafting method, four compact bone plates are inserted and are strong enough to support the head and neck. The defects of the skull can be easily replaced with artificial materials without any functional morbidity. Since skull bone grafts can be fitted to the lateral component of the resected vertebrae with cancellous bone between their outer and inner tables, they can be expected to fuse earlier than the J. Neurosurg. / Volume 76/February, 1992
fibular strut graft. In our case, the halo vest was applied for 16 weeks. The number of levels that can be fused using our method depends on individual variations of the skull shape and the vertebral body size. In our patient, the coronal suture had already closed; our measurement on the reconstructed CT scans showed that up to 8 cm of grafted bone could be inserted, if needed. The cephalic index of this patients was 77.2% and, being of Japanese descent, his skull is slightly scaphocephalic. In addition, the skull is more brachycephalic in Japanese individuals than in Caucasians. 6 Due to these considerations, the skull may possibly be the first choice of bone graft source for multilevel anterior cervical fusion requiring long, sturdy grafts. 301
T. Tanaka, et al.
FIG. 7. Computerized tomography scans obtained 24 months after the third operation showing bone fusion at the C-4 (left), C-5 (center), and C-6 (right) vertebral bodies. References 1. Abe H, Iwasaki Y, [su T, et al: [Anterior decompression for ossification of the posterior longitudinal ligament of the cervical spine.] Neurosurgeons 4:251-260, 1985 (Jpn) 2. Abe H, Tsuru M, Ito T, et al: Anterior decompression for ossification of the posterior longitudinal ligament of the cervical spine. J Neurosurg 55:108-116, 1981 3. Bernard TN Jr, Whitecloud TS III: Cervical spondylotic myelopathy and myeloradiculopathy. Anterior decompression and stabilization with autogenous fibula strut graft. Clin Orthop 221:149-160, 1987 4. Brown JA, Havel P, Ebraheim N, et al: Cervical stabilization by plate and bone fusion. Spine 13:236-240, 1988 5. Cantore GP, Ciapetta P, Delfini R, et al: Fibular graft in anterior surgery of cervical spondyloarthrosis myelopathy. Zentralbl Neuroehir 47:111-115, 1986 6. Chung CS, Runck DW, Bilben SE, et al: Effects of interracial crosses on cephalometric measurements. Am J Phys Anthropol 69:465-472, 1986 7. Doi K, Kawai S, Sumiura S, et al: Anterior cervical fusion using the free vascularized fibular graft. Spine 13: 1239-1244, 1988 8. Freidberg SR, Gumley G J, Pfeifer BA, et al: Vascularized fibular graft to replace resected cervical vertebral bodies. Case report. J Neurosurg 71:283-286, 1989 9. Gore DR: Technique of cervical interbody fusion. Clin Orthop 188:191-195, 1984 10. Gore DR, Sepic SB: Anterior cervical fusion for degenerated or protruded discs. A review of one hundred fortysix patients. Spine 9:667-671, 1984 11. Ikehata K: [Post-operative clinical and radiographical study on the partial vertebrectomy and fusion of the cervical spine.] Nippon Geka Hokan 51:118-143, 1982 (Jpn) 12. Kamikozuru M, Yamaura I, Fujii K, et at: [Multi-segmental (more than 4 vertebrae) anterior decompression 302
13. 14. 15.
16. 17.
18. 19. 20. 21.
for myelopathy, caused by the ossification of the posterior longitudinal ligament in cervical spine.] Rinsho Seikei Geka 12:416-424, 1977 (Jpn) Otani K, Miyamoto T, Nemoto K, et al: [Anterior strut bone grafting of the spine using vascular pedicle rib.] Rinsho Seikei Geka 21:593-599, 1986 (Jpn) Shinomiya K, Yamauchi K, Sato M, et al: [Anterior cervical internal fixation using sapphire screws and fibular plate.[ Rinsho Seikei Geka 20:473-480, 1985 (Jpn) Sumiura S: [Free vascularized fibula graft applied to anterior body fusion of the cervical spine - - clinical and experimental study.] Nippon Seikeigeka Gakkai Zasshi 63:308-319, 1989 (Jpn) Sumiura S, Doi K, Ihara K, et al: [Free vascularized bone graft. Second report.] Chubu Nihon Seikei Geka Saigai Geka Gakkai Zasshi 29:2349-2351, 1986 (Jpn) Sumiura S, Doi K, Kuwata N, et al: [Clinical results and problems of the cervical anterior fusion using free vascularized fibular graft.] Rinsho Selkei Geka 23:1017-1021, 1988 (Jpn) Yomimura K, Sakou T, Maehara T, et al: [Cervical anterior fusion using fibular bone graft.] Nishi Nippon Sekitsui Kenkyukaishi 6:54-57, 1980 (Jpn) Whitecloud TS: Complications of anterior cervical fusion. AAOS 27:223-227, 1978 Whitecloud TS, LaRocca H: Fibular strut graft in reconstructive surgery of the cervical spine. Spine 1:33-43, 1976 Youdas JW, Wood MB, Cahalan TD, et al: A quantitative analysis of donor site morbidity after vascularized fibula transfer. J Orthop Res 6:621-629, 1988
Manuscript received December 19, 1991. Accepted in final form July 1t, 1991. Address reprint requests to: Tokutaro Tanaka, M.D., Department of Neurosurgery, Yaizu Municipal Hospital, 1000 Dobara, Yaizu, Shizuoka Prefecture 425, Japan.
J. Neurosurg / Volume 76/February, 1992
Multilevel anterior cervical fusion using skull bone grafts Case report TOKUTARO TANAKA, M.D., TOSHIAKI NINCHOJI, M.D., KENICHI UEMURA, M.D., HmOSHl RYU, M . D , MASASH[ SUGIURA, M.D., HARUYUKl OHISHL M.D.,
MAMORU TOMITA, M.D., SEIYA TAKEHARA, M.D., AND TAKAMICHIYAMAMOTO, M.D. Departments of Neurosurgery, Yaizu Municipal Hospital, Yaizu; Kyoritsu Kikugawa Hospital, Kikugawa; Hamamatsu UniversitySchool of Medicine and Medical Center Hospital Hamamatsu; and Shinshiro MunicipalHospital, Shinshiro, Japan ~" The successful use of autogenous skull bone grafts for a C3-7 anterior cervical fusion is reported and compared with results using other bone grafts. A 5 l-year-old man with C4-7 anterior cord compression due to spurs and ossified posterior longitudinal ligaments developed progressive tetraparesis following a minor head injury. He underwent anterior decompression and fusion. On two occasions an iliac graft had failed; however, a graft of autogenous skull bone was successful. The skull bone was found superior to bone from other sites, such as the iliac crest, rib, tibia, and fibula, showing sufficient strength and less morbidity. The skull may be a better source of graft material for multilevel anterior cervical fusion, which requires long and strong grafts. 9 anterior cervical fusion 9 bone graft posterior longitudinal ligament spondylosis
KEy WORDS
ULTILEVEL anterior cervical decompression and fusion procedures have been widely employed in the treatment of myelopathy due to a long ossified posterior longitudinal ligament and/ or multilevel cervical spondylosis. 2'7'~L~2'~5 Reported sources for bone graft include the iliac crest, rib, tibia, and fibulaY ~~176There are several problems associated with these grafts. A graft from the iliac crest cannot be shaped to the exact size desired, is not strong enough, 4"~~176 and is complicated by hip pain. Rib grafts are not strong, 8 and few have been reported. The donor sites for tibial grafts fracture frequently.~~ Fibular bone is strong enough for grafting, but the triangle-shaped graft in its cross section has exhibited some difficulty in fusing to the resected vertebrae 7'~3~5'16and its donor site shows functional morbidity. 2~ We present a case of successful C3-7 anterior cervical fusion using skull bone grafts and discuss the advantages of this method.
M
Case Report This 51-year-old man was struck on the right forehead in a motorcycle accident on September 21, 1988. He developed motor weakness of both upper extremi298
9 cervical spine
ties and was immediately brought to our neurosurgical service. Examination. Neurological examination on admission showed an acute central cord syndrome, dominant on the left side. He could barely move the left upper extremity against gravity. The muscle strength of the right upper extremity was greater than the left, but also below normal. He showed decreased sensation to pinprick over his neck and both upper extremities. The muscle strength of the lower extremities was normal. Lateral cervical x-ray films showed a segmental ossified posterior longitudinal ligament from C-4 to C-5 and posterior spurs from C-5 to C-7. Conventional and computerized tomography (CT) myelography showed anterior cord compression by the ossified posterior longitudinal ligament and spurs. A dynamic study of neck flexion and extension showed no instability. The patient returned to his previous work 25 days after injury, with instructions to use a Philadelphia collar. About 8 weeks after the injury, the patient developed a slowly progressive left dominant tetraparesis and distally dominant decreased sensation to pinprick over the lower extremities. It was learned that he had seldom worn the neck collar. Magnetic resonance (MR) imagJ. Neurosurg. / Volume 76 / February, 1992
Anterior cervical fusion using skull bone grafts
FIG. 1. Magnetic resonance image showing anterior cord compression extending from C-4 to C-7.
FIG. 3. Schematic drawing of our method of using skull bone grafts for multilevel anterior cervical fusion.
FIG. 2. Cervical x-ray films. Left: Film obtained 3 days after a right iliac crest bone graft showing the first iliac graft fracture (arrow). Right: Film obtained 5 weeks after a left iliac crest bone graft showing the second iliac graft fracture
(arrow).
ing showed multilevel anterior cervical cord compression corresponding to that revealed on a previous CTmyelography study (Fig. 1). Operations. The patient underwent surgery 16 weeks after the injury. The ossified posterior longitudinal ligament and spurs were resected and an anterior cervical fusion from C-3 to C-7 was carried out with a bicortical bone graft from the fight iliac crest. A halo vest was applied immediately. By the next day, the subjective motor weakness and hypesthesia had improved, the left dominant tetraparesis was slightly better, and the decreased sensation to pinprick over the
J. Neurosurg / Volume 76/February, 1992
lower extremities had disappeared except for the soles of the feet. Three days later, however, a lateral cervical x-ray film showed that the grafted bone had fractured (Fig. 2 left). Five days after the first operation, a new and wider bone graft from the left iliac crest was inserted. A halo vest was applied with great care. Two weeks after the second operation, the patient started gait training. Anteroposterior and lateral cervical x-ray films were taken once a week. During the 5th week after surgery, the grafted bone was again found to be fractured (Fig. 2 right). In the third operation, we used skull bone grafts. Our method is shown schematically in Fig. 3. Parasagittal CT sections perpendicular to the skull surface and reconstructed from 1-mm slice axial scans were obtained for measurement. Measurement on the lateral cervical x-ray films showed that new bone grafts must be longer than 60 mm, and measurement from the reconstructed CT scans showed that it was possible to obtain 65-mm grafts posterior to the coronal suture. The patient underwent a third operation on March 20, 1989. Two plates of parasagittal skull were resected and shaped to the exact size. The top and bottom of these plates were notched by drilling to avoid the graft slipping out postoperatively. Cranioplasty with methyl 299
T. Tanaka, et al.
FIG. 4. Cervical x-ray films. Left: Intraoperative film, lateral view, showing the two skull bone grafts in place. The top and bottom of the grafts were notched to avoid postoperative slipping. Right: Postoperative film, anteroposterior view, showingthe two symmetrical skull bone plates inserted back-to-back.
methacrylate was performed concurrently. The grafts were then inserted (Fig. 4) and the gap between the plates was packed with bone dust from the skull. A halo vest was applied immediately. Postoperative Course. The patient's neurological condition was essentially unchanged from that after the first surgery. The postoperative course was uneventful. The halo vest was removed 16 weeks after the third operation under fluoroscopic control to ensure that there was no instability, and a Philadelphia collar was applied. The patient was discharged from the hospital 20 weeks after the third operation, and subsequently returned to his previous work. An MR image obtained 7 months after the third operation showed adequate anterior decompression (Fig. 5 left). A lateral cervical x-ray film obtained 9 months after the third operation showed bone fusion (Fig. 5 right). Two years after the third operation, there was no cervical deformity and the patient was working at full capacity. The latest cervical films and CT scans, taken 20 and 24 months after the last surgery, showed good bone fusion and sufficient anterior decompression (Figs. 6 and 7). Discussion Peripheral Donor Sites The reported sources of bone grafts for multilevel anterior cervical fusion are the iliac crest, rib, tibia, and fibula. 3'7''~176The problems associated with the use of iliae grafts are as follows: 1) the curved iliac crest consists chiefly of cancellous bone with a very thin layer of compact bone on its surface; 2) long grafts from the iliac crest cannot be shaped to the exact size desired and are not strong enough; 3) the donor site often fractures;l,7.11,12,14,2o and 4) painful hip with or without a donor-site fracture is a frequent complication.
300
FIG. 5. Postoperative studies, lateral view. Left: Magnetic resonance image obtained 7 months after the third operation showing adequate anterior decompression. Right: Cervical x-rayfilm obtained 9 months after the third operation showing bone fusion.
A tibial graft is straight and strong, but the donor site frequently fractures. Gore and Sepic '~ reported that, among 107 patients, 15 developed stress fracture at the tibial graft donor site; thereafter, they began to use a fibular graft. Whitecloud and LaRocca2~ have used a fibular strut graft after corticocancellous bone graft fracture. Tomimura, et al., ~s reported that they had abandoned using iliac grafts because long, sturdy grafts had not been available from the ilium and had also ceased obtaining tibial grafts after a donor-site fracture. Recently, many surgeons have come to use a fibular graft for multilevel anterior cervical fusion because straight, strong graft material with enough length can be excised. 3-5'9'~~176 The diaphysis of the fibula consists of pure compact bone and is strong enough, but a fibular graft needs a much longer time to fuse than other grafts. The triangle-shaped fibular graft in its cross section does not easily fuse to the lateral component of the resected vertebrae in the middle portion. Whitecloud and LaRocca2~estimated that a fibular strut bone graft needs approximately 1 year to fuse. Otani, et al., ~3 reported that a 10-cm fibular strut graft needs 2 years to fuse. A free vascularized fibular graft involving microvascular anastomosis has been used recently to obtain early bone fusion; 7'~6.~7 however, the muscle sleeve around the bone inhibits bone fusion in the middle portion 7'~5 and the donor site shows functional morbidity. Youdas, et aL, 2' reported that muscle strength was significantly impaired, especially in foot inversion and eversion. Such functional morbidity should be avoided in patients who might have gait disturbance due to myelopathy. Few rib grafts for anterior cervical fusion have been reported. Freidberg, et al., 8 pointed out that rib bone is not strong even when it is vascularized. Its curve, tubular structure, and the complication of opening the J. Neurosurg. / Volume 76/February, 1992
Anterior cervical fusion using skull bone grafts
FIG. 6. Cervical x-ray films obtained 20 months after the third operation. The flexion (upper left), neutral (upper center), and extension (upper right) postures show good upper bone fusion. The patient's shoulders overshadowed the lower edges of the grafted bone, although his upper extremities were strongly pulled down. The anteroposterior (lower left), fight anterior oblique (lower center), and left anterior oblique (lower right) views show good bone fusion of the lower edges of/he graft.
thorax may also be reasons for the few reports of its use.
Skull as Donor Site The skull bone consists of a thick compact outer table and a less thick inner table, with cancellous bone between them. In our grafting method, four compact bone plates are inserted and are strong enough to support the head and neck. The defects of the skull can be easily replaced with artificial materials without any functional morbidity. Since skull bone grafts can be fitted to the lateral component of the resected vertebrae with cancellous bone between their outer and inner tables, they can be expected to fuse earlier than the J. Neurosurg. / Volume 76/February, 1992
fibular strut graft. In our case, the halo vest was applied for 16 weeks. The number of levels that can be fused using our method depends on individual variations of the skull shape and the vertebral body size. In our patient, the coronal suture had already closed; our measurement on the reconstructed CT scans showed that up to 8 cm of grafted bone could be inserted, if needed. The cephalic index of this patients was 77.2% and, being of Japanese descent, his skull is slightly scaphocephalic. In addition, the skull is more brachycephalic in Japanese individuals than in Caucasians. 6 Due to these considerations, the skull may possibly be the first choice of bone graft source for multilevel anterior cervical fusion requiring long, sturdy grafts. 301
T. Tanaka, et al.
FIG. 7. Computerized tomography scans obtained 24 months after the third operation showing bone fusion at the C-4 (left), C-5 (center), and C-6 (right) vertebral bodies. References 1. Abe H, Iwasaki Y, [su T, et al: [Anterior decompression for ossification of the posterior longitudinal ligament of the cervical spine.] Neurosurgeons 4:251-260, 1985 (Jpn) 2. Abe H, Tsuru M, Ito T, et al: Anterior decompression for ossification of the posterior longitudinal ligament of the cervical spine. J Neurosurg 55:108-116, 1981 3. Bernard TN Jr, Whitecloud TS III: Cervical spondylotic myelopathy and myeloradiculopathy. Anterior decompression and stabilization with autogenous fibula strut graft. Clin Orthop 221:149-160, 1987 4. Brown JA, Havel P, Ebraheim N, et al: Cervical stabilization by plate and bone fusion. Spine 13:236-240, 1988 5. Cantore GP, Ciapetta P, Delfini R, et al: Fibular graft in anterior surgery of cervical spondyloarthrosis myelopathy. Zentralbl Neuroehir 47:111-115, 1986 6. Chung CS, Runck DW, Bilben SE, et al: Effects of interracial crosses on cephalometric measurements. Am J Phys Anthropol 69:465-472, 1986 7. Doi K, Kawai S, Sumiura S, et al: Anterior cervical fusion using the free vascularized fibular graft. Spine 13: 1239-1244, 1988 8. Freidberg SR, Gumley G J, Pfeifer BA, et al: Vascularized fibular graft to replace resected cervical vertebral bodies. Case report. J Neurosurg 71:283-286, 1989 9. Gore DR: Technique of cervical interbody fusion. Clin Orthop 188:191-195, 1984 10. Gore DR, Sepic SB: Anterior cervical fusion for degenerated or protruded discs. A review of one hundred fortysix patients. Spine 9:667-671, 1984 11. Ikehata K: [Post-operative clinical and radiographical study on the partial vertebrectomy and fusion of the cervical spine.] Nippon Geka Hokan 51:118-143, 1982 (Jpn) 12. Kamikozuru M, Yamaura I, Fujii K, et at: [Multi-segmental (more than 4 vertebrae) anterior decompression 302
13. 14. 15.
16. 17.
18. 19. 20. 21.
for myelopathy, caused by the ossification of the posterior longitudinal ligament in cervical spine.] Rinsho Seikei Geka 12:416-424, 1977 (Jpn) Otani K, Miyamoto T, Nemoto K, et al: [Anterior strut bone grafting of the spine using vascular pedicle rib.] Rinsho Seikei Geka 21:593-599, 1986 (Jpn) Shinomiya K, Yamauchi K, Sato M, et al: [Anterior cervical internal fixation using sapphire screws and fibular plate.[ Rinsho Seikei Geka 20:473-480, 1985 (Jpn) Sumiura S: [Free vascularized fibula graft applied to anterior body fusion of the cervical spine - - clinical and experimental study.] Nippon Seikeigeka Gakkai Zasshi 63:308-319, 1989 (Jpn) Sumiura S, Doi K, Ihara K, et al: [Free vascularized bone graft. Second report.] Chubu Nihon Seikei Geka Saigai Geka Gakkai Zasshi 29:2349-2351, 1986 (Jpn) Sumiura S, Doi K, Kuwata N, et al: [Clinical results and problems of the cervical anterior fusion using free vascularized fibular graft.] Rinsho Selkei Geka 23:1017-1021, 1988 (Jpn) Yomimura K, Sakou T, Maehara T, et al: [Cervical anterior fusion using fibular bone graft.] Nishi Nippon Sekitsui Kenkyukaishi 6:54-57, 1980 (Jpn) Whitecloud TS: Complications of anterior cervical fusion. AAOS 27:223-227, 1978 Whitecloud TS, LaRocca H: Fibular strut graft in reconstructive surgery of the cervical spine. Spine 1:33-43, 1976 Youdas JW, Wood MB, Cahalan TD, et al: A quantitative analysis of donor site morbidity after vascularized fibula transfer. J Orthop Res 6:621-629, 1988
Manuscript received December 19, 1991. Accepted in final form July 1t, 1991. Address reprint requests to: Tokutaro Tanaka, M.D., Department of Neurosurgery, Yaizu Municipal Hospital, 1000 Dobara, Yaizu, Shizuoka Prefecture 425, Japan.
J. Neurosurg / Volume 76/February, 1992
