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Anterior approach to intervertebral body fusion
Anterior
Approach
to Intervertebral
Body Fusion* ALLAN W. LOBB, M.D., JOHN F. LECOCQ, M.D., J. GARTH MOONEY, M.D., AND KIRK J. ANDERSON,M.D., Seattle, Washington
HE DEVELOPMENTof anterior interbody of the spine in recent years has paralleled changing concepts in the treatment of spondylolisthesis, Potts disease, intervertebral disk protrusion, pseudarthrosis following posterior fusion, and the occasional treatment of unstable spine fractures. The anterior approach has had its greatest support in stabilization of the involved components of spondylolisthesis. This approach has not received serious attention in the treatment of all the diseases listed, even though many surgeons have observed the case of exposure of the vertebrae. Fixation operations of the spine have been done posteriorly, in the main, according to the methods of Albee and Hibbs or modifications of these methods. In 1932 Capener [I], in England, bemoaned the inadequacy of posterior fusion for spondylolisthesis. He stated that the ideal operation would be either an anterior bone graft done transabdominally and so placed as to fix the body of the fifth lumbar vertebra to the sacrum, thus forming a buttress, or some form of anteroposterior fixation of the two halves of the divided vertebra. He stated, however, that the technical difficulties of such procedures preclude its trial. In 1938 a review by Speed [2] traced the development of the procedure as it was used in the treatment of spondylolisthesis. His initial case was one of the early cases reported and the first in this country. In the Speed procedure a drill was passed through the body of the fifth lumbar vertebra obliquely into the sacrum, and the defect was filled with a bony transplant from the tibia.
The procedure suggested by Capener .was first performed by Burns [3] in 1933 and later by Jenkins [PI. Mercer [5] in 1939 reported a variation in technic, again carried out transperitoneally. Because of the failure of bony union, in 1937 Friberg [6], in Sweden, advised that the anterior route be abandoned. Muller [7] in 1906 reported two cases of tuberculous spondylitis of the fifth lumbar, excisingithe lesion but without fusion. However, up to 1938, transabdominal fusion of the spine had been carried out in only a few instances (twelve cases with three deaths). Gjessing [8], who reported nine cases in 1951, preferred the extraperitoneal approach. At this same time a new radical approach for the treatment of Pott’s disease of the spine was suggested in Japan by Ito, Tsuchiya, and Asami [9]. It was their observation that for tuberculosis of the spine involving the vertebrae below and including the second lumbar vertebra, a paramedian incision with an extraperitoneal approach had ‘advantages, in that resection of the body was comparatively easy, and the danger of contamination ofthe peritoneum was obviated. Surgeons, including Treves [IO], had previously performed costotransversectomy through a paravertebral incision, approaching a lesion in the body of the dorsal vertebrae. Anterior cervical, dorsal, and lumbar spine fusion has been described more recently by Hodgson and Stock [ll] and Southwick and Robinson [12]. For the most part, the Hibbs and Albee technics of posterior fusion have been used in the treatment of tuberculosis. Consistent with the observation that altera-
T fusion
* Presentedat the annualmeetingof the Pacific Coast Surgical Association, Vancouver, British Columbia, February 22-25, 286
1965. Amevican Journal
of Surgery
Intervertebral tions in the structure and contour of the intervertebral disks of the fourth and fifth lumbar vertebral spaces are responsible for a large percentage of disabling conditions in the low back, and although the causes and pathologic features are well recognized, the treatment of intervertebral disk protrusion has remained controversial. The basis for this is the lack of uniformly good operative results, despite the ease of diagnosing the symptoms of the syndrome. The object of the procedure, anterior fusion, as described by Lane and Moore [13], was to remove the entire diseased disk completely with the cartilaginous end plates of the adjacent vertebra and to maintain the normal vertebral separation with plugs of homogenous or autogenous bone. An important indication is illustrated in the case report of Stein [14] in his treatment of persisting pain associated with pseudarthrosis after repeated prior posterior fusions. This is a frequent condition among the cases reported in this presentation. In the late forties, two stage procedures for the correction of severe kyphosis due to ankylosing spondylarthritis were performed by Herbert [IS] and La Chapelle [16] on several patients, using a posterior laminectomy combined with anterior osteotomy with disk excision and graft. La Chapelle conjectured at that time that “the easy accessibility of the lumbar vertebral bodies and disks suggest the applicability of this operation in rare cases of vertebral fractures and of isolated tumors. It seems, quite possible that in hernia of the disk, the entire disk can be removed and replaced by bone grafts. These considerations raise the question of whether the technic of the operation cannot be further improved, especially as regards details in the fixation of the transplanted bone and its application extended.” Anterior and posterolateral muscle-splitting incisions used in dorsolumbar sympathetic gangtonectomy resulted in an increased familiarity with the approach. Technical refinements and improved instruments, largely brought about by Harmon [17], Cloward [18]. and others, have resulted in an increased application of the procedure in the treatment of degenerative intervertebral disks and vertebral articular disease. While in the majority of instances vertebral fractures are treated by conservative means, it is common practice to treat certain unstable I’ol. Ill),
August
1965
Body
L’s7
Fusion
FIG. 1. Dra\vingsshowingrelationship of grc>:ct\-rs~c,ls to the lumbar vertebrae and the sacnlm. lesions by fusion. In this report we are including an instance in which an anterior interbody fusion is applicable. This particular approach and application of the procedure may be without precedent. ANATOMIC
APPROACH
AND
PROCEDURE
Anterior interbody fusion in our experience has been used in the cervical and lumbar areas for the conditions described, using a technic improved and applied by Harmon [19]. The exposure is through a lower abdominal paramedian incision, and it has been used comfortably in patients with all kinds of body builds. The patient is placed in the supine position, with the gallbladder bar just superior to the crest of the ilium. This allows extension of the spine when needed. Access to the retroperitoneal area is obtained, dissecting posterior to the rectus muscle and after dividing the posterior rectus sheath laterally along the linea semilunaris. The peritoneum and preperitoneal structures are reflected from the psoas muscle, thus allowing visualization of the iliac vessels,
288
Lobb et al.
FIG. 2. Photograph of drill, cannulated guide, and double-spiked retractor.
FIG.
3. Drawing
showing
bone grafts
spiked
drill
with bone pegs.
the ureter, the aorta, and the inferior vena cava as they are encountered. The peritoneum and its contents are displaced to the right. The proper disks are identified, usually with reference to the readily palpated fifth lumbar space. (Fig. 1.) In the vast majority of instances, the fifth lumbar disk may be exposed between the confluence of the common iliac veins. Ordinary exposure to the fourth and third disks is more satisfactorily accomplished by the dissection and displacement to the right of the iliac veins, vena cava, and the aorta. A useful innovation has been the twopronged, double-spiked retractor (Fig. Z), which was suggested and developed by Hallauer [19]. This instrument is driven into the adjacent vertebral bodies, the disk is opened, and a portion of the anterior ligament and annulus excised. At this time the interior of the disk and the status of the internal annulus and the nucleus pulposus may be determined. Cartilage covering the cortical vertebral plates and the
internal annulus fibrosis is loosened by sharp dissection and partially curetted. At this point a spiked metal guide (Fig. 2) is positioned centrally over the disk under consideration and firmly driven into the adjacent vertebrae. This is used as a guide and depth control as the residual disk and adjacent vertebrae are drilled. The guide is removed, additional disk material is curetted, and the posterior annulus is examined. Heterogenous or autogenous bone plugs are then inserted. These may or may not be secured with additional bone pegs, as illustrated in Figure 3. When this operation is used, there is little concern as to the side of the disk protrusion-whether it is a centrally or laterally placed protrusion or whether the nerve is involved-as the entire inner zone of the disk is subject to visual control. If there is a hazard in the anterior approach in this area, it is from failure to recognize variations in the venous pattern. The fifth lumbar disk is almost universally approachable below the confluence of the common iliac veins. (Fig. 4.) Rarely, the fourth disk will be approached in this way. Most often at the fourth level and always at the third and second levels it is necessary to displace the aorta and vena cava to the right. Certain abnormalities of the spine, such as sacralization of the fifth lumbar vertebra or a variation in the inclination of the sacrum, may complicate accurate disk localization and require the use of x-ray study for accuracy. Abnormality in the vein pattern presents the larger problem. The venous pattern in this area has rarely been considered in great detail. Variations in the iliac vessels and in the vena cava are frequent. An occasional troublesome variant is illustrated (Fig. 4), showing distal displacement of the vena cava or the confluence of the iliacs. In the normal person the anterior superior margin of the fifth lumbar disk is 1 to 2 cm. below the lower margin of the vena cava. Evidence of an abnormally large left iliac vein increases the difficulty of manipulation and displacement in a large percentage of cases. David, Milloy, and Anson [20], in a study of the lumbar, renal, and associated parietal and visceral veins, carefully defined the lumbar segmental veins, the prevertebral veins, and the ascending lumbar vein, the latter passing from the iliac vein to the subcostal, beneath the psoas major muscle. In general, the group has con6rmed other studies showing that instead of a simple segmental arrangement with three to
Intervertebral
L. axtecnrl
Body Fusion
iliac v
four segmental channels connecting the ascending lumbar vein and the inferior vena cava in a direct uncomplicated manner, it may be described as a complex arrangement. The segmental veins, with the exception of the first and fifth, usually drain into the vena cava, the first into the azygos and hemiazygos and the fifth into the iliac vein and the renal veins. The ascending lumbar veins are, with few exceptions, continuous longitudinal channels that provide a collateral route between the great veins of the pelvis and the parietal system of the thorax. This group should be added to Batson’s vertebral system of veins. Various anatomic and surgical studies have shown the importance of the lumbar system of veins as collateral venous channels following ligation of the inferior vena cava. It has not been necessary to obtain proximal and distal control of these vascular segments, as has long been taught in the management of veins and arteries in the field of dissection. However, minor hemorrhage has resulted occaGonally from failure to recognize and ade-
quately ligate the transverse lumbar veins and arteries, and, more importantly, failure to recognize the variable junction of the ascending lumbar veins with the left iliac vein (if one exists) and undue traction at this point with dissection and displacement of the vena cava to the right. This is aggravated by increased venous pressure, inasmuch as, in pursuit of satisfactory exposure, the vena cava may have been occluded in its retraction, ,4ny such defect may be handled by the usual methods of vascular repair. The ureter may be dissected free from adherent tissues and retained in the left of the field, but most often it is moved to the right with all other retroperitoneal tissues. It is usually more comfortable to ligate and divide the presacral vessels, which may include a variable presacral plexus of veins. Once the structures are displaced and the exposure is satisfactory, maintenance of this field requires a minimum of assistance. This emphasizes the importance of the spiked retractors, protecting both the patient and the surgeon. The approach to the cervical disk spaces has
Lobb et al.
290
portion of the origins of the internal oblique and transverse abdominis muscles are separated from the iliac crest. The plugs are removed from beneath the iliacus muscle. One to four plugs, 1 inch in diameter and full thickness, may be readily obtained. In approximately 50 per cent of the operations, lyophilized calf bone* was used as graft material. Criteria for the use of bone were based on the clinical evaluation and biologic assessments reported by Anderson and associates [21,222]. MATERIAL amohyoid M.(wt)'
'3nfermrThpd
R.
FIG. 5. Drawing showing the approach to the cervical vertebrae.
been through the anterior neck (Fig. 5) and has been used for surgery of the bodies of the third cervical to the first thoracic vertebrae. This approach is not unlike that used for lesions of the cervical esophagus. It may be accomplished with a short transverse incision on either the right or left side of the neck. The incision may be located at approximately the level of the anticipated disk to be removed. X-ray confirmation of the location desired must be done, ascertaining the location of a needle inserted either before the operation or during the procedure. After elevation of the platysma, the approach is direct- separation of the anterior border of the sternocleidomastoid muscle from contiguous structures, followed by separation of the midline structures from the contents of the carotid sheath. The manipulation necessary to maintain satisfactory exposure has been minimized through the use of the Cloward selfretaining cervical retractors. Excision of the disk and the insertion of the bone graft are accomplished with instruments smaller than, but otherwise similar to, those used in the dorsolumbar area. Possible complications are recurrent nerve damage, Horner’s syndrome, and vertebral artery damage. Also, it is possible to lacerate the esophagus. All such complications may be readily avoided. Autogenous bone, when used, has been obtained from the left ilium. A technic has been devised to cut the necessary plugs from within the pelvis through the paramedian abdominal incision. The subcutaneous tissues are separated from the external oblique aponeurosis. A portion of the insertion of this muscle and a
An orthopedic evaluation of indications for operations and any attempt to evaluate long term results of operation are not intended at this time. A total of one hundred procedures is included, involving the same number of patients. Thirteen anterior fusions were carried out involving the cervical spine, and eighty-seven were accomplished for lumbar spine disease. Of the latter, ten were fusions for spondylolisthesis; the average age in this group was twenty-two years. There was a single instance of lumbar body fusion involving the second, third, and fourth lumbar vertebrae, to stabilize a severe compression and pedicle fracture of the third lumbar vertebra. The remaining seventy-six anterior fusions were performed for unstable, painful low back problems, with or without existing protruded intervertebral disks. The patients in the group frequently represented prior laminectomy and/or fusion failure. Thirty-nine patients had eighty-eight previous operations. Of these, forty-five were industrial, compensation-supported cases. The average operating time was ninety minutes. This included the time necessary for excision of iliac bone for grafts in approximately 50 per cent of the operations. The average measured blood loss for the entire series was 370 cc. The average hospital stay was 13.4 days. Ambulation began on the first postoperative day in a supporting brace. Support continued for three to six months. COMPLICATIONS
In the lumbar fusions, massive hemorrhage, usually due to vein injury, has been the principal fear of orthopedic surgeons. This did not occur in this series. Minor injury to the left iliac vein occurred on five occasions. Most of the patients were questioned regarding the complication of impotence, but transient impotence was reported by only one. Thrombophlebitis occurred on four occasions ; pulmonary
*
Furnished
Sons.
through
the courtesy
of
E. R. Squibb &
Intervertebral embolism resulted once. Another patient with presumptive evidence of pulmonary embolism was treated. There were two minor wound infections, and respiratory complications occurred twice. lleus was never severe or prolonged. Partial nerve excision occurred once, without apI)arent residual abnormaIity. One death occurred nine days after operation during an influenza epidemic. Postmortem examination showed death due to severe myocarditis, pneumonitis. hepatitis, and nephritis, probably of viral origili. SUivIX~IKY
Highlights in the history of anterior intervertebral body fusion are reviewed. Reference is made to its use in the treatment of spondylolisthesis, tuberculosis of the spine, pseudarthrosis following posterior spine fusion, intervertebral disk protrusion, and unstable spine fracture. The technic and complications of anterior cervical and lumbar spine fusion operations are recorded. Critical evaluation of indications for operation and of long term results are not attempted at this time. REFERENCES
Brd. J. Surg., 1R: 1. CAPEMER, N. Spondylolisthesis. 374, 1932. 2. SPEED, Ii. Spondylolisthcsis; treatment by anterior bone graft. Arch. Surg., 37: 175, 1938. :!. BURNS, B. H. Operation for spondylolisthesis. Lancet, 1: 1233, 1933. 4. JKNKINS, J. A. Spondylolisthesis. Brit. J. Surg., 24: 80, 1936. 5. MERCER, W. Spondylolisthesis: with description of a new method of operative treatment and notes of ten cases. Edinburgh M. J., 43: 545, 1936. (i. FRIBERG, S. Studies on spondylolisthesis. ilcta chir. scnndinair , supplements, 82 and 55, 1939. W. Transperitoneale Freilegung der 7. MULLER, Wirbelsaulc bei tuberkuloser Spondylitis. Lkutsche Ztschr. f. Chir., 85: 128, 1906. 8. GJESSING, M. H. Osteoplastic anterior fusion of lower himbar spine in spondylolisthesis, localized spondylosis and tuberculous spondylitis. Actn oulhop. sc~endinav.. 20: 200, 19.51. :t. Ilo, H., TXJ~HIYA, J., and ASAMI, G. A new radical operation for Potts disease. J. Bone & Joint Surg., 16: 499, 1934. of psoas abscess 10. TREVES, F The direct treatment with caries of the spine. Medico-Chir. Tr., 6’7: 113, 1884. spine 11. H~~GSON, A. R. and STOCK, F. E. Anterior fusion for the treatment of tuberculosis of the spine. J. Bone &f Joint Surg., 42A: 295, 1960. 12. SOUTH\YICK, W. 0. and ROBINSON, R. A. Surgical approaches to vertebral bodies in cervical and lumbar areas. J. Bone &? Joint Surg., 39A: 631, 1957. Vol
Body
Fusion
13. LASE, J. L)., JR. and MOOKE, E. S., JR. Trailsperitoneal approach to the intervertebral disc in Illmbar arced. Ann. .yurg., 12i: 537, 1948. 14. STEIN, 1~. 0. Xnterior spine fusion; case report. 1<~11. ties/,. Joint /As., 13: 32‘2. 3952. 1s. HEKREK.I., J. J. Vertebral ostcotomy; technique, illtlications and rv\ults. J. Hnne &a Joint .Ytr,g.,
;31t,4: WI, 194x. 16. LA CEIAPEI.I,E, E. H Osteotomy
Ii.
18.
19.
20.
21.
22.
of lumbar spine for correction of kyphosis in a case of ankylosing sl)ondylarthritii. J. Bone & Joint Szrrg., 2841: 831, 1916. HARMON, I’. 1-I. Indications for spinal fusion in lllmbar diskopathy. instability and arthrosis. (‘/in. Orthop., 31: 73, lQ61. CLO\\-AKD. I<. R. Treatment of ruptured lumbar itltcrvertcbral discs by vertebral body fusion; indications, operative technic, after care. J. *Yeuuoszlrg., 10: 151, 1953. HAKMOS, I’. H. Anterior extraperitoneal lumbar disc excision and vertebral body fusion. Clin, Cjrthop., lli: 169, 1961. DAVID, K. A., MILLOY, F. J., JR., and AXSON, B. J. Lumbar, renal and associated parietal and visceral veins based upon a study of 100 specimens. Surg. Gvner. & O/lst., 1Oi: 1, 1958. ANI)ERSOS, I;. J., LE COCQ, J. F., and MOONEY, J G., Clinical evaluation of processed heterogcnous bone transplants. Clin. Orthop., 29: 248, 1063. AIWERSOS, h. J. The biological assessment of processed hetcrogenous bone in the spectrum of experimental and clinical bone grafting. To be publishrd. DISCUSSION
EDWARD B. SPEIR one of the important
(Seattle, Wash.): problems facing
Back pain is the medical
profession today. Dr. Herbert Modlin, director of the Menninger Foundation’s Law and Psychiatry Division recentlv stated that about 100,000 claims for industrial accjdent insurance pavments were filed in the state last year and that 20 to 30 per cent of the money paid on those claims (about $7 million) was for “psychologic back pains.” Persons with the continuing back pain after adequate treatment can be divided into three classes: inadequate personalities mixed with only slight education, constricted personalities that art unable to adjust to changes in their situations, and those with latent emotional problems. It is estimated that roughly one third of the cases of back pain are psychologic, one-third resp:md to conservative measures, and one-third require operative treatment of one kind or another. -4s diagnostic methods improve, surgical diseases, such as tuberculosis, ruptured disk, degenerative disease, etc., will be sorted out from the n&surgical diseases which do not respond favorably to operative therapy. Traditionally, the spine has been attacked pasteriorly. Dr. Lobb has described an anterior approach and has shown better operative exposure with excellent results.
292
Lobb et al.
JOHN RAAF (Portland, Ore.): In 1961 I was given the opportunity to review the case histories of a series of thirty-three patients upon whom anterior cervical fusion had been performed in Oregon by another group of surgeons. My evaluation consisted mainly in determining from the charts the number of anterior fusions that had been carried out in these patients. Sixty-three anterior fusions had been performed on the thirty-three patients. Nineteen of the patients had had one operation; five patients had had two; six patients had had three; two patients had had four; and one patient had had nine operations Nine of the patients were known to have pseudoarthrosis and twelve of the thirty-three patients, after having various anterior fusions, had posterior fusions performed. I would question the success of an operation when it was necessary to repeat the procedure as many times as in this series. If a fusion is indicated I prefer a posterior fusion because the nerve roots can be more adequately inspected and the complications are less.
In my opinion the incidence of pseudoarthrosis is less in posterior fusion. One question I would like to ask the authors is whether they believe diskography of value. WILLIAM H. SUTHERLAND (Vancouver, B. C.): May I ask Dr. Lobb, how many vertebrae can you fuse in the spine? One level? Two levels? ALLAN W. LOBB (closing): A large percentage are two levels, although there may be multiple fusions. I think the indications for fusion for cervical disk disease are very limited. Our principal indication in the lumbar spine has been prior posterior fusion failure with pseudoarthrosis and painful unstable low spines. The treatment of spondylolisthesis has been first degree only. I think the literature in general confirms the use of the procedure in Pott’s disease. Diskography has not been used in this group of cases. Confirmation of disk disease with saline injection has been used and has, in general, confirmed our impression of a diseased disk space.
American
Journal
of Surwy
Approach
to Intervertebral
Body Fusion* ALLAN W. LOBB, M.D., JOHN F. LECOCQ, M.D., J. GARTH MOONEY, M.D., AND KIRK J. ANDERSON,M.D., Seattle, Washington
HE DEVELOPMENTof anterior interbody of the spine in recent years has paralleled changing concepts in the treatment of spondylolisthesis, Potts disease, intervertebral disk protrusion, pseudarthrosis following posterior fusion, and the occasional treatment of unstable spine fractures. The anterior approach has had its greatest support in stabilization of the involved components of spondylolisthesis. This approach has not received serious attention in the treatment of all the diseases listed, even though many surgeons have observed the case of exposure of the vertebrae. Fixation operations of the spine have been done posteriorly, in the main, according to the methods of Albee and Hibbs or modifications of these methods. In 1932 Capener [I], in England, bemoaned the inadequacy of posterior fusion for spondylolisthesis. He stated that the ideal operation would be either an anterior bone graft done transabdominally and so placed as to fix the body of the fifth lumbar vertebra to the sacrum, thus forming a buttress, or some form of anteroposterior fixation of the two halves of the divided vertebra. He stated, however, that the technical difficulties of such procedures preclude its trial. In 1938 a review by Speed [2] traced the development of the procedure as it was used in the treatment of spondylolisthesis. His initial case was one of the early cases reported and the first in this country. In the Speed procedure a drill was passed through the body of the fifth lumbar vertebra obliquely into the sacrum, and the defect was filled with a bony transplant from the tibia.
The procedure suggested by Capener .was first performed by Burns [3] in 1933 and later by Jenkins [PI. Mercer [5] in 1939 reported a variation in technic, again carried out transperitoneally. Because of the failure of bony union, in 1937 Friberg [6], in Sweden, advised that the anterior route be abandoned. Muller [7] in 1906 reported two cases of tuberculous spondylitis of the fifth lumbar, excisingithe lesion but without fusion. However, up to 1938, transabdominal fusion of the spine had been carried out in only a few instances (twelve cases with three deaths). Gjessing [8], who reported nine cases in 1951, preferred the extraperitoneal approach. At this same time a new radical approach for the treatment of Pott’s disease of the spine was suggested in Japan by Ito, Tsuchiya, and Asami [9]. It was their observation that for tuberculosis of the spine involving the vertebrae below and including the second lumbar vertebra, a paramedian incision with an extraperitoneal approach had ‘advantages, in that resection of the body was comparatively easy, and the danger of contamination ofthe peritoneum was obviated. Surgeons, including Treves [IO], had previously performed costotransversectomy through a paravertebral incision, approaching a lesion in the body of the dorsal vertebrae. Anterior cervical, dorsal, and lumbar spine fusion has been described more recently by Hodgson and Stock [ll] and Southwick and Robinson [12]. For the most part, the Hibbs and Albee technics of posterior fusion have been used in the treatment of tuberculosis. Consistent with the observation that altera-
T fusion
* Presentedat the annualmeetingof the Pacific Coast Surgical Association, Vancouver, British Columbia, February 22-25, 286
1965. Amevican Journal
of Surgery
Intervertebral tions in the structure and contour of the intervertebral disks of the fourth and fifth lumbar vertebral spaces are responsible for a large percentage of disabling conditions in the low back, and although the causes and pathologic features are well recognized, the treatment of intervertebral disk protrusion has remained controversial. The basis for this is the lack of uniformly good operative results, despite the ease of diagnosing the symptoms of the syndrome. The object of the procedure, anterior fusion, as described by Lane and Moore [13], was to remove the entire diseased disk completely with the cartilaginous end plates of the adjacent vertebra and to maintain the normal vertebral separation with plugs of homogenous or autogenous bone. An important indication is illustrated in the case report of Stein [14] in his treatment of persisting pain associated with pseudarthrosis after repeated prior posterior fusions. This is a frequent condition among the cases reported in this presentation. In the late forties, two stage procedures for the correction of severe kyphosis due to ankylosing spondylarthritis were performed by Herbert [IS] and La Chapelle [16] on several patients, using a posterior laminectomy combined with anterior osteotomy with disk excision and graft. La Chapelle conjectured at that time that “the easy accessibility of the lumbar vertebral bodies and disks suggest the applicability of this operation in rare cases of vertebral fractures and of isolated tumors. It seems, quite possible that in hernia of the disk, the entire disk can be removed and replaced by bone grafts. These considerations raise the question of whether the technic of the operation cannot be further improved, especially as regards details in the fixation of the transplanted bone and its application extended.” Anterior and posterolateral muscle-splitting incisions used in dorsolumbar sympathetic gangtonectomy resulted in an increased familiarity with the approach. Technical refinements and improved instruments, largely brought about by Harmon [17], Cloward [18]. and others, have resulted in an increased application of the procedure in the treatment of degenerative intervertebral disks and vertebral articular disease. While in the majority of instances vertebral fractures are treated by conservative means, it is common practice to treat certain unstable I’ol. Ill),
August
1965
Body
L’s7
Fusion
FIG. 1. Dra\vingsshowingrelationship of grc>:ct\-rs~c,ls to the lumbar vertebrae and the sacnlm. lesions by fusion. In this report we are including an instance in which an anterior interbody fusion is applicable. This particular approach and application of the procedure may be without precedent. ANATOMIC
APPROACH
AND
PROCEDURE
Anterior interbody fusion in our experience has been used in the cervical and lumbar areas for the conditions described, using a technic improved and applied by Harmon [19]. The exposure is through a lower abdominal paramedian incision, and it has been used comfortably in patients with all kinds of body builds. The patient is placed in the supine position, with the gallbladder bar just superior to the crest of the ilium. This allows extension of the spine when needed. Access to the retroperitoneal area is obtained, dissecting posterior to the rectus muscle and after dividing the posterior rectus sheath laterally along the linea semilunaris. The peritoneum and preperitoneal structures are reflected from the psoas muscle, thus allowing visualization of the iliac vessels,
288
Lobb et al.
FIG. 2. Photograph of drill, cannulated guide, and double-spiked retractor.
FIG.
3. Drawing
showing
bone grafts
spiked
drill
with bone pegs.
the ureter, the aorta, and the inferior vena cava as they are encountered. The peritoneum and its contents are displaced to the right. The proper disks are identified, usually with reference to the readily palpated fifth lumbar space. (Fig. 1.) In the vast majority of instances, the fifth lumbar disk may be exposed between the confluence of the common iliac veins. Ordinary exposure to the fourth and third disks is more satisfactorily accomplished by the dissection and displacement to the right of the iliac veins, vena cava, and the aorta. A useful innovation has been the twopronged, double-spiked retractor (Fig. Z), which was suggested and developed by Hallauer [19]. This instrument is driven into the adjacent vertebral bodies, the disk is opened, and a portion of the anterior ligament and annulus excised. At this time the interior of the disk and the status of the internal annulus and the nucleus pulposus may be determined. Cartilage covering the cortical vertebral plates and the
internal annulus fibrosis is loosened by sharp dissection and partially curetted. At this point a spiked metal guide (Fig. 2) is positioned centrally over the disk under consideration and firmly driven into the adjacent vertebrae. This is used as a guide and depth control as the residual disk and adjacent vertebrae are drilled. The guide is removed, additional disk material is curetted, and the posterior annulus is examined. Heterogenous or autogenous bone plugs are then inserted. These may or may not be secured with additional bone pegs, as illustrated in Figure 3. When this operation is used, there is little concern as to the side of the disk protrusion-whether it is a centrally or laterally placed protrusion or whether the nerve is involved-as the entire inner zone of the disk is subject to visual control. If there is a hazard in the anterior approach in this area, it is from failure to recognize variations in the venous pattern. The fifth lumbar disk is almost universally approachable below the confluence of the common iliac veins. (Fig. 4.) Rarely, the fourth disk will be approached in this way. Most often at the fourth level and always at the third and second levels it is necessary to displace the aorta and vena cava to the right. Certain abnormalities of the spine, such as sacralization of the fifth lumbar vertebra or a variation in the inclination of the sacrum, may complicate accurate disk localization and require the use of x-ray study for accuracy. Abnormality in the vein pattern presents the larger problem. The venous pattern in this area has rarely been considered in great detail. Variations in the iliac vessels and in the vena cava are frequent. An occasional troublesome variant is illustrated (Fig. 4), showing distal displacement of the vena cava or the confluence of the iliacs. In the normal person the anterior superior margin of the fifth lumbar disk is 1 to 2 cm. below the lower margin of the vena cava. Evidence of an abnormally large left iliac vein increases the difficulty of manipulation and displacement in a large percentage of cases. David, Milloy, and Anson [20], in a study of the lumbar, renal, and associated parietal and visceral veins, carefully defined the lumbar segmental veins, the prevertebral veins, and the ascending lumbar vein, the latter passing from the iliac vein to the subcostal, beneath the psoas major muscle. In general, the group has con6rmed other studies showing that instead of a simple segmental arrangement with three to
Intervertebral
L. axtecnrl
Body Fusion
iliac v
four segmental channels connecting the ascending lumbar vein and the inferior vena cava in a direct uncomplicated manner, it may be described as a complex arrangement. The segmental veins, with the exception of the first and fifth, usually drain into the vena cava, the first into the azygos and hemiazygos and the fifth into the iliac vein and the renal veins. The ascending lumbar veins are, with few exceptions, continuous longitudinal channels that provide a collateral route between the great veins of the pelvis and the parietal system of the thorax. This group should be added to Batson’s vertebral system of veins. Various anatomic and surgical studies have shown the importance of the lumbar system of veins as collateral venous channels following ligation of the inferior vena cava. It has not been necessary to obtain proximal and distal control of these vascular segments, as has long been taught in the management of veins and arteries in the field of dissection. However, minor hemorrhage has resulted occaGonally from failure to recognize and ade-
quately ligate the transverse lumbar veins and arteries, and, more importantly, failure to recognize the variable junction of the ascending lumbar veins with the left iliac vein (if one exists) and undue traction at this point with dissection and displacement of the vena cava to the right. This is aggravated by increased venous pressure, inasmuch as, in pursuit of satisfactory exposure, the vena cava may have been occluded in its retraction, ,4ny such defect may be handled by the usual methods of vascular repair. The ureter may be dissected free from adherent tissues and retained in the left of the field, but most often it is moved to the right with all other retroperitoneal tissues. It is usually more comfortable to ligate and divide the presacral vessels, which may include a variable presacral plexus of veins. Once the structures are displaced and the exposure is satisfactory, maintenance of this field requires a minimum of assistance. This emphasizes the importance of the spiked retractors, protecting both the patient and the surgeon. The approach to the cervical disk spaces has
Lobb et al.
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portion of the origins of the internal oblique and transverse abdominis muscles are separated from the iliac crest. The plugs are removed from beneath the iliacus muscle. One to four plugs, 1 inch in diameter and full thickness, may be readily obtained. In approximately 50 per cent of the operations, lyophilized calf bone* was used as graft material. Criteria for the use of bone were based on the clinical evaluation and biologic assessments reported by Anderson and associates [21,222]. MATERIAL amohyoid M.(wt)'
'3nfermrThpd
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FIG. 5. Drawing showing the approach to the cervical vertebrae.
been through the anterior neck (Fig. 5) and has been used for surgery of the bodies of the third cervical to the first thoracic vertebrae. This approach is not unlike that used for lesions of the cervical esophagus. It may be accomplished with a short transverse incision on either the right or left side of the neck. The incision may be located at approximately the level of the anticipated disk to be removed. X-ray confirmation of the location desired must be done, ascertaining the location of a needle inserted either before the operation or during the procedure. After elevation of the platysma, the approach is direct- separation of the anterior border of the sternocleidomastoid muscle from contiguous structures, followed by separation of the midline structures from the contents of the carotid sheath. The manipulation necessary to maintain satisfactory exposure has been minimized through the use of the Cloward selfretaining cervical retractors. Excision of the disk and the insertion of the bone graft are accomplished with instruments smaller than, but otherwise similar to, those used in the dorsolumbar area. Possible complications are recurrent nerve damage, Horner’s syndrome, and vertebral artery damage. Also, it is possible to lacerate the esophagus. All such complications may be readily avoided. Autogenous bone, when used, has been obtained from the left ilium. A technic has been devised to cut the necessary plugs from within the pelvis through the paramedian abdominal incision. The subcutaneous tissues are separated from the external oblique aponeurosis. A portion of the insertion of this muscle and a
An orthopedic evaluation of indications for operations and any attempt to evaluate long term results of operation are not intended at this time. A total of one hundred procedures is included, involving the same number of patients. Thirteen anterior fusions were carried out involving the cervical spine, and eighty-seven were accomplished for lumbar spine disease. Of the latter, ten were fusions for spondylolisthesis; the average age in this group was twenty-two years. There was a single instance of lumbar body fusion involving the second, third, and fourth lumbar vertebrae, to stabilize a severe compression and pedicle fracture of the third lumbar vertebra. The remaining seventy-six anterior fusions were performed for unstable, painful low back problems, with or without existing protruded intervertebral disks. The patients in the group frequently represented prior laminectomy and/or fusion failure. Thirty-nine patients had eighty-eight previous operations. Of these, forty-five were industrial, compensation-supported cases. The average operating time was ninety minutes. This included the time necessary for excision of iliac bone for grafts in approximately 50 per cent of the operations. The average measured blood loss for the entire series was 370 cc. The average hospital stay was 13.4 days. Ambulation began on the first postoperative day in a supporting brace. Support continued for three to six months. COMPLICATIONS
In the lumbar fusions, massive hemorrhage, usually due to vein injury, has been the principal fear of orthopedic surgeons. This did not occur in this series. Minor injury to the left iliac vein occurred on five occasions. Most of the patients were questioned regarding the complication of impotence, but transient impotence was reported by only one. Thrombophlebitis occurred on four occasions ; pulmonary
*
Furnished
Sons.
through
the courtesy
of
E. R. Squibb &
Intervertebral embolism resulted once. Another patient with presumptive evidence of pulmonary embolism was treated. There were two minor wound infections, and respiratory complications occurred twice. lleus was never severe or prolonged. Partial nerve excision occurred once, without apI)arent residual abnormaIity. One death occurred nine days after operation during an influenza epidemic. Postmortem examination showed death due to severe myocarditis, pneumonitis. hepatitis, and nephritis, probably of viral origili. SUivIX~IKY
Highlights in the history of anterior intervertebral body fusion are reviewed. Reference is made to its use in the treatment of spondylolisthesis, tuberculosis of the spine, pseudarthrosis following posterior spine fusion, intervertebral disk protrusion, and unstable spine fracture. The technic and complications of anterior cervical and lumbar spine fusion operations are recorded. Critical evaluation of indications for operation and of long term results are not attempted at this time. REFERENCES
Brd. J. Surg., 1R: 1. CAPEMER, N. Spondylolisthesis. 374, 1932. 2. SPEED, Ii. Spondylolisthcsis; treatment by anterior bone graft. Arch. Surg., 37: 175, 1938. :!. BURNS, B. H. Operation for spondylolisthesis. Lancet, 1: 1233, 1933. 4. JKNKINS, J. A. Spondylolisthesis. Brit. J. Surg., 24: 80, 1936. 5. MERCER, W. Spondylolisthesis: with description of a new method of operative treatment and notes of ten cases. Edinburgh M. J., 43: 545, 1936. (i. FRIBERG, S. Studies on spondylolisthesis. ilcta chir. scnndinair , supplements, 82 and 55, 1939. W. Transperitoneale Freilegung der 7. MULLER, Wirbelsaulc bei tuberkuloser Spondylitis. Lkutsche Ztschr. f. Chir., 85: 128, 1906. 8. GJESSING, M. H. Osteoplastic anterior fusion of lower himbar spine in spondylolisthesis, localized spondylosis and tuberculous spondylitis. Actn oulhop. sc~endinav.. 20: 200, 19.51. :t. Ilo, H., TXJ~HIYA, J., and ASAMI, G. A new radical operation for Potts disease. J. Bone & Joint Surg., 16: 499, 1934. of psoas abscess 10. TREVES, F The direct treatment with caries of the spine. Medico-Chir. Tr., 6’7: 113, 1884. spine 11. H~~GSON, A. R. and STOCK, F. E. Anterior fusion for the treatment of tuberculosis of the spine. J. Bone &f Joint Surg., 42A: 295, 1960. 12. SOUTH\YICK, W. 0. and ROBINSON, R. A. Surgical approaches to vertebral bodies in cervical and lumbar areas. J. Bone &? Joint Surg., 39A: 631, 1957. Vol
Body
Fusion
13. LASE, J. L)., JR. and MOOKE, E. S., JR. Trailsperitoneal approach to the intervertebral disc in Illmbar arced. Ann. .yurg., 12i: 537, 1948. 14. STEIN, 1~. 0. Xnterior spine fusion; case report. 1<~11. ties/,. Joint /As., 13: 32‘2. 3952. 1s. HEKREK.I., J. J. Vertebral ostcotomy; technique, illtlications and rv\ults. J. Hnne &a Joint .Ytr,g.,
;31t,4: WI, 194x. 16. LA CEIAPEI.I,E, E. H Osteotomy
Ii.
18.
19.
20.
21.
22.
of lumbar spine for correction of kyphosis in a case of ankylosing sl)ondylarthritii. J. Bone & Joint Szrrg., 2841: 831, 1916. HARMON, I’. 1-I. Indications for spinal fusion in lllmbar diskopathy. instability and arthrosis. (‘/in. Orthop., 31: 73, lQ61. CLO\\-AKD. I<. R. Treatment of ruptured lumbar itltcrvertcbral discs by vertebral body fusion; indications, operative technic, after care. J. *Yeuuoszlrg., 10: 151, 1953. HAKMOS, I’. H. Anterior extraperitoneal lumbar disc excision and vertebral body fusion. Clin, Cjrthop., lli: 169, 1961. DAVID, K. A., MILLOY, F. J., JR., and AXSON, B. J. Lumbar, renal and associated parietal and visceral veins based upon a study of 100 specimens. Surg. Gvner. & O/lst., 1Oi: 1, 1958. ANI)ERSOS, I;. J., LE COCQ, J. F., and MOONEY, J G., Clinical evaluation of processed heterogcnous bone transplants. Clin. Orthop., 29: 248, 1063. AIWERSOS, h. J. The biological assessment of processed hetcrogenous bone in the spectrum of experimental and clinical bone grafting. To be publishrd. DISCUSSION
EDWARD B. SPEIR one of the important
(Seattle, Wash.): problems facing
Back pain is the medical
profession today. Dr. Herbert Modlin, director of the Menninger Foundation’s Law and Psychiatry Division recentlv stated that about 100,000 claims for industrial accjdent insurance pavments were filed in the state last year and that 20 to 30 per cent of the money paid on those claims (about $7 million) was for “psychologic back pains.” Persons with the continuing back pain after adequate treatment can be divided into three classes: inadequate personalities mixed with only slight education, constricted personalities that art unable to adjust to changes in their situations, and those with latent emotional problems. It is estimated that roughly one third of the cases of back pain are psychologic, one-third resp:md to conservative measures, and one-third require operative treatment of one kind or another. -4s diagnostic methods improve, surgical diseases, such as tuberculosis, ruptured disk, degenerative disease, etc., will be sorted out from the n&surgical diseases which do not respond favorably to operative therapy. Traditionally, the spine has been attacked pasteriorly. Dr. Lobb has described an anterior approach and has shown better operative exposure with excellent results.
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Lobb et al.
JOHN RAAF (Portland, Ore.): In 1961 I was given the opportunity to review the case histories of a series of thirty-three patients upon whom anterior cervical fusion had been performed in Oregon by another group of surgeons. My evaluation consisted mainly in determining from the charts the number of anterior fusions that had been carried out in these patients. Sixty-three anterior fusions had been performed on the thirty-three patients. Nineteen of the patients had had one operation; five patients had had two; six patients had had three; two patients had had four; and one patient had had nine operations Nine of the patients were known to have pseudoarthrosis and twelve of the thirty-three patients, after having various anterior fusions, had posterior fusions performed. I would question the success of an operation when it was necessary to repeat the procedure as many times as in this series. If a fusion is indicated I prefer a posterior fusion because the nerve roots can be more adequately inspected and the complications are less.
In my opinion the incidence of pseudoarthrosis is less in posterior fusion. One question I would like to ask the authors is whether they believe diskography of value. WILLIAM H. SUTHERLAND (Vancouver, B. C.): May I ask Dr. Lobb, how many vertebrae can you fuse in the spine? One level? Two levels? ALLAN W. LOBB (closing): A large percentage are two levels, although there may be multiple fusions. I think the indications for fusion for cervical disk disease are very limited. Our principal indication in the lumbar spine has been prior posterior fusion failure with pseudoarthrosis and painful unstable low spines. The treatment of spondylolisthesis has been first degree only. I think the literature in general confirms the use of the procedure in Pott’s disease. Diskography has not been used in this group of cases. Confirmation of disk disease with saline injection has been used and has, in general, confirmed our impression of a diseased disk space.
American
Journal
of Surwy