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`NUVASIVE 1024
`NuVasive, Inc. v. Warsaw Orthopedic, Inc.
`IPR2013-00208
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`

`

`The Results of 150 Anterior Lumbar Interbody
`
`Fusion Operations Performed by Two Surgeons
`
`in Australia
`
`ARIHISA FUJIMAKI, M.D.,* HENRY V. CROCK, M.D., M.S., F.R.C.S., F.R.A.C.S.,* AND
`SIR GEORGE M. BEDBROOK, M.D.. M.S., F.R.C.S., F.R.A.C.S.**
`
`The results presented in this paper are
`based on the studies of an independent ob-
`server (A.F.) carried out during his tenure
`of a postgraduate fellowship in Australia.
`Six months was spent interviewing 100 pa-
`tients who had been operated on by one
`coauthor (H.V.C.) and a further 50 patients
`who had been operated on by the other coau-
`thor (G.M.B.)
`
`M ETHODS
`
`Secretarial staff arranged all of the appoint-
`ments without reference to the two surgeons who
`had performed the operations. In due course, each
`patient was interviewed independently by (A.F.)
`using a standard proforma. Physical examinations
`were carried out and pre- and postoperative roent-
`genograms were inspected, new films being ob-
`tained in most cases at the time of review.
`
`PREOPERATIVE DIAGNOSIS
`
`The indications for spinal fusion in this group
`of 150 patients are listed in Table 1. They are based
`on the acceptance and recognition of nonprolapsing
`disc disorders as an important cauSe of back and
`leg pain by the coauthors (G.M.B. and H.V.C.)
`The definitions of these pathologic entities have
`been published previously by Crock.”
`Fusion had been attempted in- 75 female and
`
`75 male patients at 188 intervertebral disc spaces.
`The patients ranged in age from 19 to 62 years
`(average, 41.6 years). The frequency and number
`of fusions performed at different intervertebral
`levels are shown in Table 2.
`The mechanism of injury in 69 patients was
`industrial; in 23 patients, a motor car accident;
`and in 16 patients, sperts related. In 42 patients
`there was no history of injury. The data on these
`patients was gathered, considered, and classified
`into three groups: GrOup l (84 cases): those pa-
`tients in whom their first and only spinal operation
`had been an interbody fusion; Group II (38 cases):
`those patients in whom interbody fusion had fol-
`lowed some other spinal operation; and Group III
`(28 cases): those patients in whom supplementary
`operations had been performed following lumbar
`interbody fusion Operation. The rationale for these
`operations, to decompress the spinal canal and
`nerve root canals following anterior lumbar in-
`terbody fusions. has been described by Crock.‘
`The results, including information on occupa-
`tion. time lost from work and on ultimate reem-
`ployment are listed for each group in Table 3.
`In a recent publication on anterior fusion of the
`lumbar spine, Flynn and Hoque' devoted consid-
`erable discussion to the radiologic evidence of fu-
`sion. We believe that the technique of involving
`the use of fibular bone is‘ unacceptable. Using the
`method. described previously by Crock,7 roentgen-
`ographic findings of fusion and nonunion were
`assessed, and the results are listed in Table 4.
`
`‘ Melbourne, Australia.
`” Perth. Western Australia.
`Reprint requests to H. V. Crock, M.D., St. Vincent's
`Hospital, Melbourne 3000, Australia.
`Received: September IO. I98 I .
`
`COMPLICATIONS
`
`When complications are discussed in re-
`lation to the use of interbody fusion opera-
`tions,
`there was a striking difference in
`
`0009-92lX/82/0500/ I64 $00.70 © J. B. Lippincott Co.
`
`164
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` 2
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`

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`Number 186
`May. 1982
`
`adopted attitudes between their previous use
`in tuberculous disease of the spine and their
`wider current use in the management of
`common lumbar spinal disorders. Tubercu-
`losis was life threatening and crippling. Di-
`rect surgical approach to the offensive ag-
`gressive foci had some heroic appeal, but the
`surgical
`techniques that
`succeeded were
`really quite crude, aided by the use of an-
`tituberculous chemotherapy. Low back pain
`sufferers, on the other hand, present with a
`different mystique: their problems are not
`easily solved, diagnosis is difficult, and liti-
`gation among them abounds. The same sur-
`gical techniques which brought success in
`the management of spinal tuberculosis have
`fallen far short of satisfactory when applied
`to these various disorders; a nonunion rate
`
`of 37% was reported in a recently published
`series from Hong Kong.l
`Thus, with the use of a technique that
`allows repeated, reproducible accuracy, lum-
`bar interbody fusions can be achieved in a
`high percentage of cases with a wide range
`of disorders of the lumbar spine.
`Providing that the surgeon has had ade-
`quate training and experience in its use, the
`potential complications of large vessel dam-
`age, ureteric, dural sac, nerve root or cauda
`equina injury should not occur. Paralytic
`ileus is rarely seen with extraperitoneal ap-
`proaches to the spine inasmuch as nothing
`is administered orally in the postoperative
`period until bowel sounds are audible or fia-
`tus has been passed. Furthermore, naso-gas-
`tric suction is used only when persistent ab-
`dominal distension occurs. Closed suction
`
`drainage of the retroperitoneal space and
`graft donor sites prevents blood accumula-
`tion, which might otherwise lead to the de-
`velopment of paralytic ileus.
`Ureteric injury has not occurred in any
`of our cases; but, transient urine retention
`is relatively common during the first day
`after operation. Disturbances of ejaculation
`are rare. Deep vein thrombosis is still of
`major concern with an incidence, based on
`clinical grounds, of approximately 3%. Spu-
`
`Anterior Lumbar lnterbody Fusion
`
`165
`
`TABLE 1. Preoperative Diagnosis
`
`Disc disruption
`Disc degeneration
`Spondylolisthesis
`Isolated disc resorption
`Disc prolapse
`Miscellaneous
`
`79
`29
`l 9
`10
`8
`5
`
`150
`
`turn retention and its consequential problems
`can be prevented by the routine use of chest
`physiotherapy in the postOperative period.
`Wound infections have been rare. One
`
`coauthor (I-I.V.C.) has had two cases of ver-
`tebral body infections in 20 years’ experi-
`ence, one of which required several drainage
`operations and chemotherapy for more than
`12 months.
`
`DISCUSSION
`
`This paper reports on the results obtained
`following interview and examination of 150
`patients without reference to the surgeons
`who had performed their operations (G.M.B.
`50 cases, and I-I.V.C. 100 cases). All surgical
`techniques used were basically identical. It
`is clear from reviews in the literature that
`
`this valuable operation has failed to gain the
`acceptance it deserves for a number of rea-
`sons. Cloward2 advocated a transspinal canal
`approach using cadaveric bone for interbody
`
`TABLE 2. The Frequency and Number
`of Fusions Performed at Different
`Intervertebral Levels
`
`Single-Level
`Fusions
`
`Double-Level
`Fusions
`
`Sites
`Numbers
`Sires
`Numbers
`
`
`14—3—34
`[44—4-5
`[4.5—145—5]
`
`LI—z
`142-3
`L34
`1.4.,
`Ls—S.
`
`1
`1
`4
`l 8
`88
`
`l l 2
`
`1
`7
`30
`
`38
`
`
`
` 3
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`

`

`166
`
`Fujimakl. et al.
`
`Glnleal
`
`TABLE 3. Summary of Findings
`
`Time Off
`Resumed Same
`Other
`Did Not Return
`
`Group
`Occupation
`(Months)
`Occupation
`Occupation
`to Work
`
`1
`
`2
`
`Nonsedentary
`Home duties
`Sedentary
`
`Nonsedentary
`Home duties
`Sedentary
`
`49
`18
`17
`84
`
`23
`7
`8
`38
`
`l 1.8
`3.3
`7.4
`
`24.0
`5.6
`6.5
`
`39
`16
`17
`
`14
`6
`7
`
`7
`l
`0
`
`6
`0
`0
`
`3
`l
`0 "
`
`-
`
`3
`1
`l
`
`3
`
`6
`3
`10
`16.5
`19
`Nonsedentary
`l
`1
`3
`11.5
`5
`Home duties
`2
`0
`2
`12.5
`4
`Sedentary
`28
`
`fusion; but, few surgeons could match his
`technical skill. Wiltberger” advocated a
`dowel method of intervertebral body fusion
`to be performed through the spinal canal,
`and for similar reasons this operation failed
`to gain many proponents. Leaving aside the
`vexed question of indications, the safe and
`reliable performance of anterior interbody
`fusion demands the acquisition of skills that
`
`TABLE 4. Radiological Assessment
`
`
`
` Group GM. B. H. V. C.
`
`
`
`l. 84 Cases
`Union
`Nonunion
`
`2. 38 Cases
`Union
`Nonunion
`
`3. 28 Cases
`Union
`Nonunion
`
`26 cases
`24
`2
`
`16 cases
`16
`0
`
`8 cases
`8
`0
`
`58 cases
`56
`2
`
`22 cases
`21
`l
`
`20 cases
`l9
`1
`
`
`
`
`
`48 (96%)Total union 96 (96%)
`
`are not taught in most orthopedic centers—
`techniques of far less sophistication than
`those used in everyday open heart opera-
`tions. Furthermore, the reputation of the
`procedure has been damaged by the pub-
`lished results from the Mayo Clinic; Stauffer
`and Coventryl0 reporting on 83 cases in eight
`years performed by seven surgeons. More
`recently Flynn and Hoque,s also from the
`United States, reported on 52 patients treated
`by this operation in a 12 year period: thirty-
`six of these cases were performed by one
`surgeon and 16 by three other surgeons. The
`rate of operation averaged four cases per
`year.8
`Neither of these papers stands up to sci-
`entific criticisms that could be leveled at the
`
`purely technical aspects of interbody fusion
`methods. The blood supply of the lumbar
`vertebral bodies is not disturbed in the an-
`
`terior fusion techniques using dowel cutting
`instruments or osteotomes. Yet, one of the
`
`reasons for graft failure put forward by
`Stauffer and Coventry,‘O was that the blood
`supply of the vertebral bodies was relatively
`poor. In the two major papers referred to
`
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`Nunber 165
`May. 1982
`Anterior Lumbar Interbody Fusion 167
`
`
`
`from the United States, no surgeon appeared
`to have more experience with the operation
`than in 36 cases performed during many
`years.
`
`The method used by the co-authors in the
`present series, described previously in detail
`by Crock,’ is advocated because the use of
`the special instruments allows reproducible
`accuracy. There is no doubt, however, that
`a high level of proficiency has been reached
`involving the use of interbody fusion tech-
`niques with cutting of dowel cavities by hand
`using osteotomes. Freebody et al.9 have used
`this technique in the management of high
`grade vertebral slips in spondylolisthesis,
`with spectacular success.
`
`SUMMARY
`
`The work of two Australian surgeons us-
`ing the same techniques for anterior lumbar
`interbody fusion operations in 150 patients
`has been analyzed by an independent ob-
`server (A.F.). Used as a primary procedure
`in 84 cases, only four patients failed to return
`to work. Time off work varied between 3.3
`
`to 11.8 months, depending on the patients’
`occupations. Used as a salvage procedure in
`38 cases, only five patients failed to return
`to work. Time off work varied between 24
`
`and 5.6 months depending on the patients‘
`
`occupations. In 28 cases, supplementary op-
`erations were performed following interbody
`fusions. Even in this difficult group only nine
`patients failed to return to work.
`
`REFERENCES
`
`1. Chow. S. P., Leong. J. C. Y.. Ma. A.. and Yau,
`A. C. B. C.: Anterior spinal fusion for deranged
`lumbar intervenebral disc. Spine 5:452, I980.
`2. Cloward. R. 13.: The treatment of ruptured lumbar
`intervertebral discs by vertebral body fusion. Neu-
`rosurgery 10:I54. 1953.
`3. Crock. H. V.: A reappraisal of intervenebral disc
`lesions. Med. J. Aust. 1:983. I970.
`4. Crock. H. V.: Isolated lumbar disc resorption as a
`cause of nerve root canal stenosis. Clin. Orthop.
`1152109, 1976.
`5. Crock, H. V.: Traumatic disc injury. In Vinken and
`Bruyn (eds) Handbook of Clinical Neurology. Am-
`sterdam. North-Holland Publishing Co., I976. pp.
`481—51 I.
`6. Crock. H. V.: Observations on the management of
`failed spinal operations. J. Bone Joint Surg. 58-
`13:193. I976.
`7. Crock, H. V.: Anterior lumbar interbody fusion,
`indications for its use and notes on surgical tech-
`nique. Clin. Orthop. 165:1981.
`8. Flynn, J. C. and Hoque, M. A.: Anterior fusion of
`the lumbar spine. J. Bone Joint Surg. 6lAzll43.
`1979.
`9. Freebody, D., Bendall, R., and Taylor. R. D.: An-
`terior transperitoneal lumbar fusion. J. Bone Joint
`Surg. 533:617. 1971.
`I0. Stauffer, R. N., and Coventry, M. 3.: Anterior in-
`terbody lumbar spine fusion. Analysis of Mayo
`Clinic Series. J. Bone Joint Surg. 54A2756, 1972.
`ll. Wiltberger. B. R.: The dowel intervenebral body
`fusion as used in lumbar disc surgery. J. Bone Joint
`Surg. 39Az284. 1957.
`
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