ANNOTATIONS
Adolescent I di (3pathi c
Scd iosis WHEN a patient asks me, ‘What does idiopathic mean?’ I usually respond: ‘The doctoir is an idiot and the patient pathelic’. While we cannot admit we are idiots., we can admit our ignorance of the etiology of scoliosis after excluding the congenital and paralytic types. The patient, however, needs to know that she or he is not really pathetic inasmuch as the condition is neither life threatening nor seriously disabling unless the curve exceeds 50 degrees at skeletal maturity, since the curve can increase 1 degree per year throughout life’. At 70 degrees clinicians have reported decreasing pulmonary function and oxygen saturation, with eventual right-sided heart failure2. Although adults who have moderately severe untreated scoliosis can complain of back pain, the data from long-term studies indicate that the incidence of low back pain is no greater in the scoliotic person than in the general population3 5 . Certainly, the rib hump deformity in the usual right thoracic curve and/or deconipensation of the curve with a shift
of the trunk in the thoracolumbar or lumbar curve are visible deformities in the naked person, and are particularly disturbing to the body image of the adolescent girl who perceives a less than perfect body. On the other hand, balanced double major curves (right thoracic and left lumbar equal in degrees) have no obvious gross trunk deformity when standing erect. My test on appearance is to have the patient garbed in a halter and trunks, bikini bathing-suit style, and then to view her from a distance of 15 to 20 feet. Then I ask whether her back looks deformed. The next question regarding a patient with newly-discovered idiopathic scoliosis is whether it can be treated and, if so, is treatment effective? A perspective on the answer to this question was sent to me by the originator of the Milwaukee Brace, Dr. Walter Blount, who sent me a reprint of a paper by A. M. Phelps published the year Dr. Blount was born, 1900: ‘Lateral curvature of the spine rises before us each year like a spectre. From every clinic in every country the orthopedic surgeon is deluging societies and medical journals with literature upon the subject . . . the positive position taken by the author is only to be retreated from a year or two later. Then, again, we find in each quarter of half a century the revival of ideas of the past, which ideas at the time they were published were considered absolutely
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correct, but after a very short time were relegated to obscurity which they so justly deserved, only to be revived again by some enthusiastic orthopedic surgeons'6. The 827 titles between January 1, 1966 and August 1 , 1990 which I gathered from the Medline data base confirmed this statement. Idiopathic scoliosis remains a favorite international topic among orthopaedic surgeons from almost every quarter of the globe. 90 years after Phelps it seems as though we are again at a change of paradigm in treatment of scoliosis; therefore, this annotation might be relevant. A comprehensive up-to-date review of the subject has been published by RINSKYand GAMBLE'.
Prevalence The prevalence of adolescent idiopathic scoliosis (AIS) of 10 degrees or more is reported to be about 2 per cent of the school population aged seven to 16 years'. Some minor variations occur among national groups (4.6 per cent, Athens; 2.4 per cent, People's Republic of China; 3.2 per cent in girls and 0.5 per cent in boys, Southern Sweden; 2.5 per cent Caucasians, 0.03 per cent African~)~.''. In the Chinese survey, 20 degree curves, which we now all concede are clinically significant, had a prevalence of only 0.1 per cent". Consequently, the data do not suggest that we are dealing with an AIS' epidemic.
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Etiology Although a good deal of research has been devoted to discovering the cause, it is still elusive. Inasmuch as scoliosis is not found in the animal kingdom other than in upright humans, the possibility of some defect in the brain and spinal cord postural mechanisms has been explored, but with only a hint of validation of this concept". Convincing research has demonstrated no primary abnormality of vertebral growth except in those cases resulting from congenital malformations of the vertebrae. Although paralytic diseases such as poliomyelitis, muscular dystrophy, spinal muscular atrophy and cerebral palsy have a high incidence of scoliosis, the attempt to transfer the obvious muscle imbalance in these conditions to the idiopathic type has been
equivocal. The data on familial incidence and the well-known higher occurrence in girls have led to an hypothesis of a sexlinked genetic cause2'* 2 1 923. In other words, when you can blame no one else for your plight, it's your mother.
Pathomechanics It is now clear that the scoliotic deformity is three-dimensional: a combination of a lateral deviation, kyphosis or lordosis and rotation. In idiopathic thoracic scoliosis, the evidence points to the mechanism as a rotatary lordosis. Astute observers have noted the rarity of significant lateral curvatures in children who have a juvenile kyphosisZ3* 24. Diagnosis and Assessment The classic clinical finding for the common right-thoracic scoliosis is a posterior rib hump seen on 90 degrees flexion of the trunk. A loin crease and deviation of a plumb line dropped from the spinous process of the first thoracic vertebra or mid-occiput are other clinical findings, especially in thoracolumbar and lumbar curves. I have observed that inequality of shoulder levels is a less reliable sign; a droop of the shoulder with a straight spine can be due to unilateral hypertrophy of an upper limb, usually found in those who consistently play tennis and pitch baseball2'. Radiographic confirmation of the scoliosis is essential. A single anteriorposterior projection on a long cassette allows measurement of the whole spine and visualization of the iliac crests so necessary to determine the extent of iliac crest ossification. Ossification of the iliac crest apophysis (Risser's sign) is the prime reliable indicator of spinal skeletal maturity, beginning with 0 ossification and progressing from 1-to indicate onefourth ossification of the crest-to 4, when the entire apophysis is ossified26. Some radiologists have suggested posterior-anterior projections, in order to decrease the dose of radiation to the breasts27*28. However, skeletal detail is not as clear with this projection. Lead breast shields can be used, and improved radiographic screens have reduced the dose of radiation. A lateral projection of the spine should always be included in the
first visit; often missed is spondylolisthesis, which can cause a spinal curvature. Bending films are unnecessary unless the curve is in the currently acceptable 'treatable' range, either by an orthosis or surgery. There is no other way to determine flexibility and prognosis for treatment. Moire* photography, a technique of topographic mapping of the back, can discern scoliosis, but is not diagnostic29. 30. We have used it in follow-up, in order to decrease the number of radiographs by alternating the Moire Polaroid photographs, with radiographs at the visits. A neurological examination is a must. One of the most common presentations of a spinal cord tumor is scoliosis3'. Today magnetic resonance imaging (MRI) is a superior method to determine possible pathology of the spinal canal and cord. In our current practice, any left-thoracic curve merits MRI; we have found at least six cases of silent syringomyelia in leftthoracic ~ c o l i o s i s ~ ~ . The onset of the menarche is important for determining prognosis and treatment. Unfortunately, it seems overlooked in the majority of studies reported and probably also in clinical practice. After menarche only 15 per cent of curvatures progress33. At this point spinal growth velocity begins to decrease. In boys the only equivalent clinical sign of decreasing spinal growth is the need for the first shave34.
then the risk of progression was considered to be 68 per cent45. What is clearly established is the progression of the curve during the peak of spinal growth velocity46. Because curves over 50 degrees will progress by 1 degree per year after skeletal maturity, most surgeons advise surgical correction and stabilization of curves over 50 degrees'.
Treatmen t When we attempted to do a metaanalysis47 of orthotic treatment derived from 10 published studies, we found our task impossible because not all used the same skeletal maturity indicators; most did not include, for example, the onset of the m e n a r ~ h e ~ ' .In ~ ~the . 10 studies, six used the Milwaukee brace5'; the others used the thoracolumbar plastic molded orthoses, also named according to city of origin: Boston 5 6 , Miami (one)52 and Wilmington (one)55. (The only European city brace of which I am aware is from L,yon, France".) All claimed good results in a mixed bag of patients, according to curve measurement and age of application. In Japan, where the screening is mandatory and the study and treatment of scoliosis is intensive, YAMAGUCHIand colleagues found that in two-thirds of their patients the scoliosis was not progressive whether the brace was worn or not6'. Adding to the puzzle of assessing results are the two different principles Natural History upon which these orthoses are based. The Milwaukee brace is thought to enforce My associate (v.G.) and I recently reviewed 13 studies on the natural history dynamic correction (the child shifts the of scoliosis, and found a variation of trunk away from the lateral pressure pad progression among the studies of 5 to 89 in a confined space between the neck ring per cent and non-progression from 11 to and the pelvic mold), whereas all the other 95 per cent4. 5 , 12, 33-42 . In a detailed study orthoses are based on static compression forces on the spine. by MILLERet a f . of curvatures from 15 to 30 degrees only 25 per cent p r o g r e ~ s e d ~ ~ . While these 11 studies of orthotic LONSTEINreported only a 23 per cent treatment emphasized the absolute necessity to wear the orthosis or brace for progression in curves of 20 to 29 degrees 20 to 23 hours each day, other subsequent when the Risser sign was 2 or 3 (one-half to three-quarters of iliac crest apophyseal studies indicated equally good results with ossification); if the Risser sign is 0 to 1, part-time wear of 16 hours per day, i.e. after school6'. To add to the confusion, night bracing with Charleston (South * M o i r t = a cloth, especially silk, that has a wavy Carolina) plastic lateral trunk-bend pattern; a watered pattern produced on cloth; moire effect = the effect of superimposing a repetitive orthosis, worn only while sleeping, is said design, such as a grid. (Morris, W. 1981) The to be effective62. American Heritage Dictionary of the English Languuge. Boston: Houghton Mifflin. More doubt on efficacy of brace
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treatment was instilled by DIRAIMONDO et al., who found only 15 per cent compliance with brace wear in their patiend3. In a benign condition like scoliosis-in contrast to, for example, a life-threatening infection-it should come as no surprise to find adolescents skipping brace wear when no one is looking. Certainty of the degree of curvature measured on radiographs has been attacked by three studies that have demonstrated approximately a 7 degree error in the standard Cobb measurement of the curvature, dependent upon selection of end-vertebrae, inclination of lines drawn and use of a wax pencil rather than a fine line p e n ~ i l ~ Of - ~ ~equal . importance is the realization of dependence on the patient’s position when the radiograph is made: slight trunk rotation toward the cassette will increase the projected curve, rotation away will decrease the measurement68. Where does this leave conservative treatment indications in 1990? Treatment will seldom be imposed if we accept the studies of ROGALAet al. and others who have consistently shown that only approximately 0 . 3 per cent of all children with scoliosis followed needed treatment36. From the data published it seems that only curvatures from 30 to 40 degrees, and from 20 to 30 degrees in those who have a definite progression of > 6 to 7 degrees and who are pre-menarcheal patients with a Risser sign of 0 to 1, should be treated with whichever brace or orthosis you like4’, 56. What is especially important when advising the patient and parents is that no brace or orthosis has actually corrected the curvature; on follow-up all curves return to their original degree69*70. As with special physiotherapy exercises, enthusiasm for electrical stimulation of the paravertebral muscles has dampened after initial promising reports71. Acknowledging the standard 7 degree error in radiographic measurement and the likelihood of brace/orthotic treatment to fail in curves greater than 40 degrees when the spine is still growing, it is obvious that the indications for instituting orthotic treatment are confined to curvatures in an extremely narrow range. Current surgical indications are rapidly progressing curvatures uncontrolled by
brace or orthosis, thoracic curves with thoracic lordosis, continued decompensated spines despite orthotic or brace use; and the child should be older than 10 years of age, preferably 12 years or more. Because the criteria used by surgeons in the decision of surgery are so varied, prevalence data are not exact. In general, surgical correction seems to be needed in 22 to 30 per cent of all cases followed. Surgery With the introduction of effective instrumentation and spinal fusion by HARRINGTONin 196272, surgical instrumentation has blossomed and has become more and more effective. For right-thoracic curves the CotrelDubousset instrumentation from France appears quite effective73; the method of DICKSONof Britain, using a kyphotic Harrington rod with the interlaminar wiring technique devised by LUQUE of Mexico, is also effective74375.The Wisconsin system of interspinous process segmental fixation seems useful for small or more fragile ~ e r t e b r a e ~ Thora~. columbar curves have been treated by localized anterior disc excision and Zielke instrumentation from Germany with impressive r e s ~ l t s ~ ~ . ~ ~ . Curve correction is usually at least 50 per cent, but this depends upon the flexibility of the curve. The feasibility and safety of anterior disc excision and fusion as a preliminary to posterior correction for rigid severe curves have allowed good corrections. Patients and parents need to be told that the objective of surgery is not a perfectly straight spine, but a balanced one, in which the fusion prevents progression throughout life. Sturdy internal fixation, as with the Cotrel-Dubousset system, has eliminated the need for postoperative plasters or o r t h ~ s e s ~The ~ . advance of effective instrumentation and spine fusion has steadily reduced time in hospital for idiopathic scoliosis surgery during my professional life from about one year, before 1962, to an average of between five and eight days in 1989-an impressive statistic which ought to bring tears of joy to groaning and moaning health care planners and economists. Much progress has been made in
learning the natural history of adolescent idiopathic scoliosis, and in the efficacy of conservative treatment with braces or orthotics. The question ‘To brace or not to brace?’ cannot be answered with total assurances0. However, the data presented are sufficiently uncertain on this issue that, if an orthopaedic surgeon practicing between the tropics of Cancer and Capricorn in an emerging country does not wi,sh to burden the adolescent with a confining brace or orthosis, and the costs, no one should be critical. Perhaps, in the developed world, bracing fulfills the patient and physician’s need to ‘do something’ and also ensures follow-up during growth, so that significant progression can be detected. Great progress has been made in surgical treatment. The only thing left to do is discover the etiology.
EUGENEE. BLECK Stanford University, 520 Willow Road, Palo Alto, California. Acknowledgement The author wishes to thank Vincent Gomez, M.D.-a visiting scholar at Stanford University from Manila, Philippines-for review of published reports on natural history and orthotic treatment of scoliosit;. References 1. Weinstein. S. L., Ponseti, I. V. (1983) ‘Curve progression in idiopathic scoliosis.’ Journal of Bone and Joint Surgery, 65A, 447-455. 2. Winter, R. B., Lovell, W. W., Moe, J . J. (1975) ‘Excessive thoracic lordosis and loss of pulmonary function in patients with idiopathic scoliosis.’ Journal of Bone and Joint Surgery, 57 A, 972-977, 3. Nachemson, A. (1968) ‘A long term follow-up study of non-treated scoliosis.’ Acta Orthopaedica Scandinavica, 39, 466-476. 4. Collis, D. K . , Ponseti, I. V. (1969) ‘Long-term follow-up of patients with idiopathic scoliosis not treated surgically.’ Journal of Bone and Joint Surgery, SlA, 425-445. 5 . Weinstein, S. L., Zavala, D. C., Ponseti, I. V . (1’981) ‘Idiopathic scoliosis-long-term followup and prognosis in untreated patients.’ Journal of Bone and Joint Surgery, 63A, 702-7 12. 6. Phelps, A. M. (1900) ‘Observations in lateral curvature of the spine. Transactions of the A,merican Orthopedic Association, 13. 7. Rinsky, L. A., Gamble, J. G. (1988) ‘Adolescent idiopathic scoliosis.’ Western Journal of Medicine, 148, 182-191. 8. Nachemson, A., Lonstein, J., Weinstein, S. L. (1982) ‘Report of the prevalence and natural history committee.’ Paper presented at the Scoliosis Research Society annual meeting, Denver, Colorado, September.
9. Shands, A. R., Eisberg, H . B. (1955) ‘The incidence of scoliosis in the State of Delaware-A study of 50,000 minifilms of th: chest made during a survey for tuberculosis. Journal of Bone and Joint Surgery, 31, 1232-1249. 10. Kane, W. J., Moe, J . H . (1970) ‘A scoliosis prevalence survey in Minnesota.’ Clinical Orthopaedics and Related Research, 69, 216-21 8 . 11. Bellyei, A., Czeizel, A., Barta, O., Magda, T., Molnar, L. (1977) ‘Prevalence of adolescent idiopathic scoliosis in Hungary.’ Acta Orthopaedica Scandinavica, 48, 177-1 80. 12. Brooks, H . L., Azen, S. P., Gerberg, E., Brooks, R., Chan, I. (1975) ‘Scoliosis: a prospective epidemiologic study.’ Journal of Bone and Joint Surgery, SlA, 968-972. 13. Segil, C. M. (1974) ‘The incidence of idiopathic scoliosis in the Bantu and white population groups of Johannesburg.’ Journal of Bone and Joint Surgery, 56B, 393. (Abstract.) 14. Smyrnis, P . N., Valavanis, J., Alexopoulos, A , , Siderakis, G., Giannestras, N. J. (1979) ‘School screening for scoliosis in Athens.’ Journal of Bone and Joint Surgery, 61B, 2 15-21 7. 15. Smyrnis, P. N., Valvanis, J., Voutsinas, S., Alexopoulos, A., lerodiaconou, M. (1980) ‘Incidence of scoliosis in the Greek Islands.’ In Zorab, P. A., Siegler, D. (Eds.), Scoliosis. London: Academic Press. pp. 13-18. 16. O’Brien, J. P. (1980) ‘The incidence of scoliosis in Oswestry.’ In Zorab, P . A , , , Siegler, D. (Eds.) Scoliosis. London: Academic Press. pp. 19-29. 17. Willner, S., Uden, A. (1982) ‘A prospective prevalence study of scoliosis in southern Sweden.’ Acta Orthopaedica Scandinavica, 53, 233-237. 8. Pin, L. H . , Mo, L. Y . , Lin, L., Hua, H. P., Hui, D. S., Chang, B. D., Chang, Y. Y. (1985) ‘Early diagnosis of scoliosis based on schoolscreening.’ Journal of Bone and Joint Surgery, 67A, 1202- 1205. 9. Adler, N. S., Bleck, E. E., Rinsky, L. A., Young, W. (1986) ‘Balance reactions and eye; hand coordination in idiopathic scoliosis. Journal of Orthopaedic Research, 4, 102-107. 20. Wynne-Davies, R. (1968) ‘Familial (idiopathic) scoliosis-a family survey.’ Journal of Bone and Joint Surgery, SOB, 24-30. 21. Cowell, H . R., Hall, J. N., MacEwen, G. D. (1972) ‘Genetic amects of idiooathic scoliosis.’ Clinical Orthopaedics and Related Research, 86. 121-131. 22. Naihemson,A., Sahlstrand, A. (1977) ‘Etiologic factors in adolescent idiopathic scoliosis.’ Spine, 2, 176-184. 23. Dickson, R. A , , Lawton, J . O., Archer, I. A,, Butt, W. P . (1984) ‘The pathogenesis of idiopathic scoliosis.’ Journal of Bone and Joint Surgery, 66B, 8-15. 24. Dickson, R. A. (1988) ‘The aetiology of spinal deformities.’ Lancet, 1, 1151-1155. 25. Jones, H . H., Priest, J. D., Hayes, W. C., Tichenor, C. C., Nagel, D. A. (1977) ‘Humeral hypertrophy in response t o exercise.’ Journal of Bone and Joint Surgery, 59A, 204208. 26. Risser, J . C., Ferguson, A. B. (1936) ‘Scoliosis: its prognosis.’ Journal of Bone and Joint Surgery, 18, 667-670. 27. Rao, P. S., Gregg, E. C. (1984) ‘A revised estimate of the risk of carcinogenesis from xrays to scoliosis patients.’ Investigative Radiology, 19, 58-60.
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28. Hoffman, D. A., Lonstein, J . E., Morin, M. M., Visscher, W., Harris, B. S., Boice, J. R. (1989) ‘Breast cancer in women with scoliosis exposed to multiple diagnostic x-rays.’ Journal of National Cancer Institute, 81, 1307-1312. 29. Adair, I. V., van Wijk, M. C., Armstrong, G. W. D. (1977) ‘Moire topography in scoliosis screening.’ Clinical Orthopaedics and Related Research, 129, 165-171. 30. Adler, N. S., Csongradi, J., Bleck, E. E. (1984) ‘School screening for scoliosis: one experience in California using clinical examination and moire photography.’ Western Journal of Medicine, 141, 631-633. 31. Tachdjian, M. O., Matson, D. D. (1965) ‘Orthopaedic aspects of intraspinal tumors in infants and children.’ Journal of Bone and Joint Surgery, 41A, 223-248. 32. Rinsky, L. A. (1989) Personal communication. 33. Clarisse, P. (1974) ‘Pronostic evolutif des scolioses idiopathique mi?eures de 10” a 29” en periode de cronissance. Thesis, Universite Claude-Bernard, Lyon. Cited in Moe, J . H., Winter, R. B., Bradford, D. S., Lonstein, J. E. (1978) Scoliosis and Other Spinal Deformities. Philadelphia: W. B. Saunders. p. 58. 34. Terver, S., Kleinman, R., Bleck, E. E. (1980) ‘Growth landmarks and the evolution of scoliosis: a review of pertinent studies on their usefulness.’ Developmental Medicine and Child Neurology, 22, 675-684. 35. Fowles, J. V., Drummon, D. S., L’Ecuyer, S., Roy, L., Mohamed, T. K. (1978) ‘Untreated scoliosis in the adult.’ Clinical Orthopaedics and Related Research, 134, 212-217. 36. Rogala, E. J., Drummond, D. S., Gum, J . (1978) ‘Scoliosis: incidence and natural history. A prospective epidemiological study.’ Journal of Bone and Joint Surgery, 60A, 173-1 76. 37. Scott, M. M., Piggott, H. (1981) ‘A short-term follow-up of patients with mild scoliosis.’ Journal of Bone and Joint Surgery, 63B, 523-525. 38. Fustier, T. (1980) ‘Evolution radiologique spontanee des scolioses idiopathiques de moins de 45” en periode de crossance: etude graphique retrospective de cent dossiers du Centre de Readaptation Fonctionnelle des Massues. ’ Thesis, I’Universite‘ ClaudeBernard, Lyon. Cited in Weinstein, S. L. (1988) Adolescent Idiopathic Scoliosis: Prevalence, Natural History, Treatment Indications. (Monograph prepared by the Scoliosis Research Society and American Academy of Orthopaedic Surgeons’ Committee on the Spine.) 39. Lonstein, J . E., Carlson, J. M. (1984) ‘The prediction of curve progression in untreated idiopathic scoliosis during growth.’ Journal of Bone and Joint Surgery, 66A, 1061-1071. 40. Picault, C., de Mauroy, J. C., Mouilleseaux, B., Diana, G. (1986) ‘Natural history of idiopathic scoliosis in girls and boys.’ Spine, 11, 777-778. 41. Bunnell, W. P. (1986) ‘The natural history of idiopathic scoliosis before skeletal maturity.’ Spine, 11, 773-776. 42. Weinstein, S. L. (1986) ‘Idiopathic scoliosis: natural history of curve progression.’ Spine, 780-783. 43. Ascani, E., Bartolozzi, P., Logroscino, C. A., Marchetti, P. G., Ponte, A., Savini, R., Travaglini, F., Binazzi, R., DiSilvestre, M. (1986) ‘Natural history of untreated idiopathic scoliosis after skeletal maturity.’ Spine, 11,
784-789. 44. Miller, J. A. A., Nachernson, A. L., Schultz, A. B. (1985) ‘Effectiveness of braces in mild idiopathic scoliosis.’ Spine, 9, 632-635. 45. Lonstein, J. E. (1989) ‘Milwaukee brace treatment of adolescent idiopathic scoliosisreview of 1020 patients.’ Paper presented at the annual meeting of the Pediatric Orthopaedic Society of North America, May. 46. Dival-Beaupere, G. (1970) ‘Le reperes de maturation dans la surveillance dans scolioses.’ Revue de Chirurgie orthopedique et reparatrice de L ’Appareil Moteur (Paris), 56, 59-76. 47. Moses, L. E., Emerson, J. D., Hosseini, H. (1984) ‘Analyzing data from ordered categories.’ New England Journal of Medicine, 311, 442-448. 48. Nordwall, A. (1973) ‘Studies in idiopathic scoliosis. Relevant to etiology, conservative and operative treatment.’ Acta Orthopaedica Scandinavica, Suppl. 150, 99-124. 49. Keiser, R. P., Shufflebarger, H. L. (1976) ‘The Milwaukee brace in idiopathic scoliosis: evaluation of 123 completed cases.’ Clinical Orthopaedics and Related Research, 118, 19-24. 50. Mellencamp, D., Blount, W. P., Anderson, A . J. (1977) ‘Milwaukee brace treatment of idiopathic scoliosis. Late results.’ Clinical Orthopaedics and Related Research, 126, 47-57. 51. Carr, W., Moe, J . H., Winter, R. B., Lonstein, J. E. (1980) ‘Treatment of idiopathic scoliosis. in the Milwaukee brace.’ Journal of Bone and Joint Surgery, 62A, 599-612. 52. McCollough, N. C., Schultz, M., Javech, N., Latta, L. (1981) ‘Miami TLSO in the management of scoliosis: preliminary results in 100 cases.’ Journal of Pediatric Orthopedics, 1, 141-152. 53. Laurnen, E. L., Tupper, J. W., Mullen, M. P. (1983) ‘The Boston brace in thoracic scoliosis: a preliminary report.’ Spine, 8, 388-395. 54. Rudicel, S., Renshaw, T. S. (1983) ‘The effect of the Milwaukee brace on spinal decompensation in idiopathic scoliosis.’ Spine, 8, 385-387. 55. Basset, G. S., Bunnell, W. P., MacEwen, G. D. (1986) ‘Treatment of idiopathic scoliosis with the Wilmington brace.’ Journal of Bone and Joint Surgery, 68A, 602-605. 56. Emans, J. B., Kaelin, A., Bancel, P., Hall, J . E., Miller, M. E. (1986) ‘The Boston bracing system for idiopathic scoliosis. Follow-up results in 295 patients.’ Spine, 11, 792-801. 57. Winter, R. B., Lonstein, J . E., Drogt, J., Noren, C. A. (1986) ‘The effectiveness of the Milwaukee brace in the non-operative treatment of thoracic idiopathic scoliosis.’ Spine, 11, 790-791. 58. Blount, W. P., Moe, J. H. (1973) TheMilwaukee Brace. Baltimore: Williams & Wilkins. 59. Michel, C. R., Caton, J., Michel, F. (19877) ‘Devenir a long terme des scolioses idiopathiques ayant subi un traitement orthopedique lyonnais.’ Revue Chirurgie Orthopddique, 13, Supp. 2, 134-137. 60. Yamaguchi, Y., Asaka, Y., Chen, W. S., Tsuji, T., Yamaguchi, T., Tsuruoka, H. (1986) ‘Follow-up results of brace treatment of adolescent idiopathic scoliosis.’ Nippon Seikeigeka Gakkai Azsshi, 60, 1079-1085. 61. Green, N. E. (1986) ‘Part-timy bracing of adolescent idiopathic scoliosis. Journal of Bone and Joint Surgery, 68A, 738-742.
62. Rinsky, L. A. (1989) Personal communication. 63. DiRaimondo, C . V., Green, N . E . (1988) ‘Brace-wear compliance in patients with adolescent idiopathic scoliosis.’ Journal of Pediatric Orthopaedics, 8, 143-846. 64. Oda, M., Rauth, S., Gregory, P. B., Silverman, F. N., Bleck, E . E . (1982) ‘The significance of roentgenographic measurement in scoliosis. Journal of Pediatric Orthopedics, 2, 378-382. 65. Morrissy, R . T., Goldsmith, G. S., Hall, E. C . , Kehl, D., Cowie, G . H. (1990) ‘Measurement of the Cobb angle on radiographs of patients who have scoliosis.’ Journal of Bone and Joint Surgery, 12A, 320-327. 66. Carman, D. L., Browne, R. H., Birch, J . G. (1990) ‘Measurement of scoliosis and kyphosis radiographs.’ Journal of Bone and Joint Surgery, 12A, 328-333. 67. Cobb, J. R . (1948) ‘Outline for the study of scoliosis.’ Insrructional Course Lectures, ‘The American Academy o f Orthopaedic Surgeons, 5, 261-275. 68. Dawson. E . G.. Smith. R. K.. McNiece, G . M. (1978) ‘Radiographic evaluation of scoliosis: a reassessment and introduction of the scoliosis chariot .’ Clinical Orthopaedics and Related Research, 131, 151-155. 69. Moe, J . H . , Winter, R . B., Bradford, D. S., Lonstein, J . E . (1978) Scoliosis and Other Spinal Deformities. Philadelphia: W . B. Saunders. p. 110. 70. Mellencamp, D. D., Blount, W. P. (1986) ‘The natural history of idiopathic scoliosis: late results revisited.’ Spine, -11, 805-806. 71. O’Donnell, C. S., Bunnell, W. P., Betz, R. R., Bowen, J . R., Tipping, C . R . (1988) ‘Electrical stimulation in the treatment of idiopathic scoliosis.’ Clinical Orthopaedics and Related Research, 229, 107-113.
72. Harrington, P . R . (1962) ‘Treatment of scoliosis. Correction and internal fixation in spine instrumentation.’ Journal of Bone and Joint Surgery, 44A, 591-610. 73. Cotrel, Y . , Dubousset, J:, Guillaumat, M. (1988) ‘New universal instrumentation in spinal surgery.’ Clinical Orthopaedics and Related Research, 227, 10-23. 74. Dickson, R . A , , Archer, I . A. (1987) ‘Surgical treatment of late-onset idiopathic thoracic scoliosis. The Leeds procedure.’ Journal 0.f Bone and Joint Surgery, 69B, 709-714. 75. Luque, E. R. (1982) ‘Segmental spinal instrumentation for correction of scoliosis.’ Clinical Orthopaedics and Related Research, 163, 192-1 98. 76. Drummond, D., Guadagnia, J., Keene, J . S., Breed, A ,, Narechania, R . (1984) ‘Interspinous process segmental spinal instrumentation.’ Journal of Pediatric Orthopedics, 4, 397-404. 77. .Moe, J . H., Purcell, G. A , , Bradford, D. S. (1983) ‘Zielke instrumentation (VDS) for the correction of spinal curvature. Analysis of results in 66 patients.’ Clinical Orthopaedics and Related Research, 180, 133- 153. 78. Ogilvie, J. W . (1988) ‘Anterior spine fusion with Zielke instrumentation for idiooathic scoliosis in adolescents.’ Orrhopedic Ciinics of North America, 19, 313-317. 79. Wojcik, A . S., Webb, J . K . , Burwell, R . G . (1989) ‘An analysis of the effect of the Zielke operation on S-shaped curves in idiopathic scoliosis The use of EVAs showing that correction of the thoracic curve occurs in its lower part: significance of the thoracolumbar spinal segment.’ Spine, 14. 625-631, 80. Edear. M. A. (1985) ‘To brace or not to brace?’ JGurnal of Bone’ and Joint Surgery, 67B, 173-174 (Editorial.)
The Tethered Cord in Myelomeningocele: Should It Be Untet hered?
1) is identical to the image of the midsagittal plane routinely obtained today by magnetic resonance imaging. LICHTENSTEIN’popularized the term ‘spinal dysraphism’ and summarized his findings by stating that these disorders may involve cutaneous, mesodermal or neural elements, singly or in combination. GARCEAU’Sdescription of the filum terminale syndrome in 19533 emphasized that progressive neurological deterioration during growth could occur and that painful scoliosis could be relieved by resection of the tight filum. More attention was focused on the occult dysraphic disorders in reports by JAMES and LASSMANin 19624 and ANDERSON in 19685. In addition to defects in bowel and bladder control, an ‘orthopaedic syndrome’ of progressive lower-extremity deformity in children was described. Salient features included motor weakness,
ONE o f the earliest pathology specimens of a ‘tethered cord in association with myelomeningocele is that of a six-weekold feimale treated by injection with Dr. Morton’s iodo-glycerine solution. This specimen, No. 145 in the Glasgow Royal Infirmary Museum, clearly depicts the low-lying conus medullaris adherent by scar tissue to the dorsal dural sac’. This anatomical lithograph by Shattock (Fig.
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Adolescent I di (3pathi c
Scd iosis WHEN a patient asks me, ‘What does idiopathic mean?’ I usually respond: ‘The doctoir is an idiot and the patient pathelic’. While we cannot admit we are idiots., we can admit our ignorance of the etiology of scoliosis after excluding the congenital and paralytic types. The patient, however, needs to know that she or he is not really pathetic inasmuch as the condition is neither life threatening nor seriously disabling unless the curve exceeds 50 degrees at skeletal maturity, since the curve can increase 1 degree per year throughout life’. At 70 degrees clinicians have reported decreasing pulmonary function and oxygen saturation, with eventual right-sided heart failure2. Although adults who have moderately severe untreated scoliosis can complain of back pain, the data from long-term studies indicate that the incidence of low back pain is no greater in the scoliotic person than in the general population3 5 . Certainly, the rib hump deformity in the usual right thoracic curve and/or deconipensation of the curve with a shift
of the trunk in the thoracolumbar or lumbar curve are visible deformities in the naked person, and are particularly disturbing to the body image of the adolescent girl who perceives a less than perfect body. On the other hand, balanced double major curves (right thoracic and left lumbar equal in degrees) have no obvious gross trunk deformity when standing erect. My test on appearance is to have the patient garbed in a halter and trunks, bikini bathing-suit style, and then to view her from a distance of 15 to 20 feet. Then I ask whether her back looks deformed. The next question regarding a patient with newly-discovered idiopathic scoliosis is whether it can be treated and, if so, is treatment effective? A perspective on the answer to this question was sent to me by the originator of the Milwaukee Brace, Dr. Walter Blount, who sent me a reprint of a paper by A. M. Phelps published the year Dr. Blount was born, 1900: ‘Lateral curvature of the spine rises before us each year like a spectre. From every clinic in every country the orthopedic surgeon is deluging societies and medical journals with literature upon the subject . . . the positive position taken by the author is only to be retreated from a year or two later. Then, again, we find in each quarter of half a century the revival of ideas of the past, which ideas at the time they were published were considered absolutely
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correct, but after a very short time were relegated to obscurity which they so justly deserved, only to be revived again by some enthusiastic orthopedic surgeons'6. The 827 titles between January 1, 1966 and August 1 , 1990 which I gathered from the Medline data base confirmed this statement. Idiopathic scoliosis remains a favorite international topic among orthopaedic surgeons from almost every quarter of the globe. 90 years after Phelps it seems as though we are again at a change of paradigm in treatment of scoliosis; therefore, this annotation might be relevant. A comprehensive up-to-date review of the subject has been published by RINSKYand GAMBLE'.
Prevalence The prevalence of adolescent idiopathic scoliosis (AIS) of 10 degrees or more is reported to be about 2 per cent of the school population aged seven to 16 years'. Some minor variations occur among national groups (4.6 per cent, Athens; 2.4 per cent, People's Republic of China; 3.2 per cent in girls and 0.5 per cent in boys, Southern Sweden; 2.5 per cent Caucasians, 0.03 per cent African~)~.''. In the Chinese survey, 20 degree curves, which we now all concede are clinically significant, had a prevalence of only 0.1 per cent". Consequently, the data do not suggest that we are dealing with an AIS' epidemic.
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Etiology Although a good deal of research has been devoted to discovering the cause, it is still elusive. Inasmuch as scoliosis is not found in the animal kingdom other than in upright humans, the possibility of some defect in the brain and spinal cord postural mechanisms has been explored, but with only a hint of validation of this concept". Convincing research has demonstrated no primary abnormality of vertebral growth except in those cases resulting from congenital malformations of the vertebrae. Although paralytic diseases such as poliomyelitis, muscular dystrophy, spinal muscular atrophy and cerebral palsy have a high incidence of scoliosis, the attempt to transfer the obvious muscle imbalance in these conditions to the idiopathic type has been
equivocal. The data on familial incidence and the well-known higher occurrence in girls have led to an hypothesis of a sexlinked genetic cause2'* 2 1 923. In other words, when you can blame no one else for your plight, it's your mother.
Pathomechanics It is now clear that the scoliotic deformity is three-dimensional: a combination of a lateral deviation, kyphosis or lordosis and rotation. In idiopathic thoracic scoliosis, the evidence points to the mechanism as a rotatary lordosis. Astute observers have noted the rarity of significant lateral curvatures in children who have a juvenile kyphosisZ3* 24. Diagnosis and Assessment The classic clinical finding for the common right-thoracic scoliosis is a posterior rib hump seen on 90 degrees flexion of the trunk. A loin crease and deviation of a plumb line dropped from the spinous process of the first thoracic vertebra or mid-occiput are other clinical findings, especially in thoracolumbar and lumbar curves. I have observed that inequality of shoulder levels is a less reliable sign; a droop of the shoulder with a straight spine can be due to unilateral hypertrophy of an upper limb, usually found in those who consistently play tennis and pitch baseball2'. Radiographic confirmation of the scoliosis is essential. A single anteriorposterior projection on a long cassette allows measurement of the whole spine and visualization of the iliac crests so necessary to determine the extent of iliac crest ossification. Ossification of the iliac crest apophysis (Risser's sign) is the prime reliable indicator of spinal skeletal maturity, beginning with 0 ossification and progressing from 1-to indicate onefourth ossification of the crest-to 4, when the entire apophysis is ossified26. Some radiologists have suggested posterior-anterior projections, in order to decrease the dose of radiation to the breasts27*28. However, skeletal detail is not as clear with this projection. Lead breast shields can be used, and improved radiographic screens have reduced the dose of radiation. A lateral projection of the spine should always be included in the
first visit; often missed is spondylolisthesis, which can cause a spinal curvature. Bending films are unnecessary unless the curve is in the currently acceptable 'treatable' range, either by an orthosis or surgery. There is no other way to determine flexibility and prognosis for treatment. Moire* photography, a technique of topographic mapping of the back, can discern scoliosis, but is not diagnostic29. 30. We have used it in follow-up, in order to decrease the number of radiographs by alternating the Moire Polaroid photographs, with radiographs at the visits. A neurological examination is a must. One of the most common presentations of a spinal cord tumor is scoliosis3'. Today magnetic resonance imaging (MRI) is a superior method to determine possible pathology of the spinal canal and cord. In our current practice, any left-thoracic curve merits MRI; we have found at least six cases of silent syringomyelia in leftthoracic ~ c o l i o s i s ~ ~ . The onset of the menarche is important for determining prognosis and treatment. Unfortunately, it seems overlooked in the majority of studies reported and probably also in clinical practice. After menarche only 15 per cent of curvatures progress33. At this point spinal growth velocity begins to decrease. In boys the only equivalent clinical sign of decreasing spinal growth is the need for the first shave34.
then the risk of progression was considered to be 68 per cent45. What is clearly established is the progression of the curve during the peak of spinal growth velocity46. Because curves over 50 degrees will progress by 1 degree per year after skeletal maturity, most surgeons advise surgical correction and stabilization of curves over 50 degrees'.
Treatmen t When we attempted to do a metaanalysis47 of orthotic treatment derived from 10 published studies, we found our task impossible because not all used the same skeletal maturity indicators; most did not include, for example, the onset of the m e n a r ~ h e ~ ' .In ~ ~the . 10 studies, six used the Milwaukee brace5'; the others used the thoracolumbar plastic molded orthoses, also named according to city of origin: Boston 5 6 , Miami (one)52 and Wilmington (one)55. (The only European city brace of which I am aware is from L,yon, France".) All claimed good results in a mixed bag of patients, according to curve measurement and age of application. In Japan, where the screening is mandatory and the study and treatment of scoliosis is intensive, YAMAGUCHIand colleagues found that in two-thirds of their patients the scoliosis was not progressive whether the brace was worn or not6'. Adding to the puzzle of assessing results are the two different principles Natural History upon which these orthoses are based. The Milwaukee brace is thought to enforce My associate (v.G.) and I recently reviewed 13 studies on the natural history dynamic correction (the child shifts the of scoliosis, and found a variation of trunk away from the lateral pressure pad progression among the studies of 5 to 89 in a confined space between the neck ring per cent and non-progression from 11 to and the pelvic mold), whereas all the other 95 per cent4. 5 , 12, 33-42 . In a detailed study orthoses are based on static compression forces on the spine. by MILLERet a f . of curvatures from 15 to 30 degrees only 25 per cent p r o g r e ~ s e d ~ ~ . While these 11 studies of orthotic LONSTEINreported only a 23 per cent treatment emphasized the absolute necessity to wear the orthosis or brace for progression in curves of 20 to 29 degrees 20 to 23 hours each day, other subsequent when the Risser sign was 2 or 3 (one-half to three-quarters of iliac crest apophyseal studies indicated equally good results with ossification); if the Risser sign is 0 to 1, part-time wear of 16 hours per day, i.e. after school6'. To add to the confusion, night bracing with Charleston (South * M o i r t = a cloth, especially silk, that has a wavy Carolina) plastic lateral trunk-bend pattern; a watered pattern produced on cloth; moire effect = the effect of superimposing a repetitive orthosis, worn only while sleeping, is said design, such as a grid. (Morris, W. 1981) The to be effective62. American Heritage Dictionary of the English Languuge. Boston: Houghton Mifflin. More doubt on efficacy of brace
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treatment was instilled by DIRAIMONDO et al., who found only 15 per cent compliance with brace wear in their patiend3. In a benign condition like scoliosis-in contrast to, for example, a life-threatening infection-it should come as no surprise to find adolescents skipping brace wear when no one is looking. Certainty of the degree of curvature measured on radiographs has been attacked by three studies that have demonstrated approximately a 7 degree error in the standard Cobb measurement of the curvature, dependent upon selection of end-vertebrae, inclination of lines drawn and use of a wax pencil rather than a fine line p e n ~ i l ~ Of - ~ ~equal . importance is the realization of dependence on the patient’s position when the radiograph is made: slight trunk rotation toward the cassette will increase the projected curve, rotation away will decrease the measurement68. Where does this leave conservative treatment indications in 1990? Treatment will seldom be imposed if we accept the studies of ROGALAet al. and others who have consistently shown that only approximately 0 . 3 per cent of all children with scoliosis followed needed treatment36. From the data published it seems that only curvatures from 30 to 40 degrees, and from 20 to 30 degrees in those who have a definite progression of > 6 to 7 degrees and who are pre-menarcheal patients with a Risser sign of 0 to 1, should be treated with whichever brace or orthosis you like4’, 56. What is especially important when advising the patient and parents is that no brace or orthosis has actually corrected the curvature; on follow-up all curves return to their original degree69*70. As with special physiotherapy exercises, enthusiasm for electrical stimulation of the paravertebral muscles has dampened after initial promising reports71. Acknowledging the standard 7 degree error in radiographic measurement and the likelihood of brace/orthotic treatment to fail in curves greater than 40 degrees when the spine is still growing, it is obvious that the indications for instituting orthotic treatment are confined to curvatures in an extremely narrow range. Current surgical indications are rapidly progressing curvatures uncontrolled by
brace or orthosis, thoracic curves with thoracic lordosis, continued decompensated spines despite orthotic or brace use; and the child should be older than 10 years of age, preferably 12 years or more. Because the criteria used by surgeons in the decision of surgery are so varied, prevalence data are not exact. In general, surgical correction seems to be needed in 22 to 30 per cent of all cases followed. Surgery With the introduction of effective instrumentation and spinal fusion by HARRINGTONin 196272, surgical instrumentation has blossomed and has become more and more effective. For right-thoracic curves the CotrelDubousset instrumentation from France appears quite effective73; the method of DICKSONof Britain, using a kyphotic Harrington rod with the interlaminar wiring technique devised by LUQUE of Mexico, is also effective74375.The Wisconsin system of interspinous process segmental fixation seems useful for small or more fragile ~ e r t e b r a e ~ Thora~. columbar curves have been treated by localized anterior disc excision and Zielke instrumentation from Germany with impressive r e s ~ l t s ~ ~ . ~ ~ . Curve correction is usually at least 50 per cent, but this depends upon the flexibility of the curve. The feasibility and safety of anterior disc excision and fusion as a preliminary to posterior correction for rigid severe curves have allowed good corrections. Patients and parents need to be told that the objective of surgery is not a perfectly straight spine, but a balanced one, in which the fusion prevents progression throughout life. Sturdy internal fixation, as with the Cotrel-Dubousset system, has eliminated the need for postoperative plasters or o r t h ~ s e s ~The ~ . advance of effective instrumentation and spine fusion has steadily reduced time in hospital for idiopathic scoliosis surgery during my professional life from about one year, before 1962, to an average of between five and eight days in 1989-an impressive statistic which ought to bring tears of joy to groaning and moaning health care planners and economists. Much progress has been made in
learning the natural history of adolescent idiopathic scoliosis, and in the efficacy of conservative treatment with braces or orthotics. The question ‘To brace or not to brace?’ cannot be answered with total assurances0. However, the data presented are sufficiently uncertain on this issue that, if an orthopaedic surgeon practicing between the tropics of Cancer and Capricorn in an emerging country does not wi,sh to burden the adolescent with a confining brace or orthosis, and the costs, no one should be critical. Perhaps, in the developed world, bracing fulfills the patient and physician’s need to ‘do something’ and also ensures follow-up during growth, so that significant progression can be detected. Great progress has been made in surgical treatment. The only thing left to do is discover the etiology.
EUGENEE. BLECK Stanford University, 520 Willow Road, Palo Alto, California. Acknowledgement The author wishes to thank Vincent Gomez, M.D.-a visiting scholar at Stanford University from Manila, Philippines-for review of published reports on natural history and orthotic treatment of scoliosit;. References 1. Weinstein. S. L., Ponseti, I. V. (1983) ‘Curve progression in idiopathic scoliosis.’ Journal of Bone and Joint Surgery, 65A, 447-455. 2. Winter, R. B., Lovell, W. W., Moe, J . J. (1975) ‘Excessive thoracic lordosis and loss of pulmonary function in patients with idiopathic scoliosis.’ Journal of Bone and Joint Surgery, 57 A, 972-977, 3. Nachemson, A. (1968) ‘A long term follow-up study of non-treated scoliosis.’ Acta Orthopaedica Scandinavica, 39, 466-476. 4. Collis, D. K . , Ponseti, I. V. (1969) ‘Long-term follow-up of patients with idiopathic scoliosis not treated surgically.’ Journal of Bone and Joint Surgery, SlA, 425-445. 5 . Weinstein, S. L., Zavala, D. C., Ponseti, I. V . (1’981) ‘Idiopathic scoliosis-long-term followup and prognosis in untreated patients.’ Journal of Bone and Joint Surgery, 63A, 702-7 12. 6. Phelps, A. M. (1900) ‘Observations in lateral curvature of the spine. Transactions of the A,merican Orthopedic Association, 13. 7. Rinsky, L. A., Gamble, J. G. (1988) ‘Adolescent idiopathic scoliosis.’ Western Journal of Medicine, 148, 182-191. 8. Nachemson, A., Lonstein, J., Weinstein, S. L. (1982) ‘Report of the prevalence and natural history committee.’ Paper presented at the Scoliosis Research Society annual meeting, Denver, Colorado, September.
9. Shands, A. R., Eisberg, H . B. (1955) ‘The incidence of scoliosis in the State of Delaware-A study of 50,000 minifilms of th: chest made during a survey for tuberculosis. Journal of Bone and Joint Surgery, 31, 1232-1249. 10. Kane, W. J., Moe, J . H . (1970) ‘A scoliosis prevalence survey in Minnesota.’ Clinical Orthopaedics and Related Research, 69, 216-21 8 . 11. Bellyei, A., Czeizel, A., Barta, O., Magda, T., Molnar, L. (1977) ‘Prevalence of adolescent idiopathic scoliosis in Hungary.’ Acta Orthopaedica Scandinavica, 48, 177-1 80. 12. Brooks, H . L., Azen, S. P., Gerberg, E., Brooks, R., Chan, I. (1975) ‘Scoliosis: a prospective epidemiologic study.’ Journal of Bone and Joint Surgery, SlA, 968-972. 13. Segil, C. M. (1974) ‘The incidence of idiopathic scoliosis in the Bantu and white population groups of Johannesburg.’ Journal of Bone and Joint Surgery, 56B, 393. (Abstract.) 14. Smyrnis, P . N., Valavanis, J., Alexopoulos, A , , Siderakis, G., Giannestras, N. J. (1979) ‘School screening for scoliosis in Athens.’ Journal of Bone and Joint Surgery, 61B, 2 15-21 7. 15. Smyrnis, P. N., Valvanis, J., Voutsinas, S., Alexopoulos, A., lerodiaconou, M. (1980) ‘Incidence of scoliosis in the Greek Islands.’ In Zorab, P. A., Siegler, D. (Eds.), Scoliosis. London: Academic Press. pp. 13-18. 16. O’Brien, J. P. (1980) ‘The incidence of scoliosis in Oswestry.’ In Zorab, P . A , , , Siegler, D. (Eds.) Scoliosis. London: Academic Press. pp. 19-29. 17. Willner, S., Uden, A. (1982) ‘A prospective prevalence study of scoliosis in southern Sweden.’ Acta Orthopaedica Scandinavica, 53, 233-237. 8. Pin, L. H . , Mo, L. Y . , Lin, L., Hua, H. P., Hui, D. S., Chang, B. D., Chang, Y. Y. (1985) ‘Early diagnosis of scoliosis based on schoolscreening.’ Journal of Bone and Joint Surgery, 67A, 1202- 1205. 9. Adler, N. S., Bleck, E. E., Rinsky, L. A., Young, W. (1986) ‘Balance reactions and eye; hand coordination in idiopathic scoliosis. Journal of Orthopaedic Research, 4, 102-107. 20. Wynne-Davies, R. (1968) ‘Familial (idiopathic) scoliosis-a family survey.’ Journal of Bone and Joint Surgery, SOB, 24-30. 21. Cowell, H . R., Hall, J. N., MacEwen, G. D. (1972) ‘Genetic amects of idiooathic scoliosis.’ Clinical Orthopaedics and Related Research, 86. 121-131. 22. Naihemson,A., Sahlstrand, A. (1977) ‘Etiologic factors in adolescent idiopathic scoliosis.’ Spine, 2, 176-184. 23. Dickson, R. A , , Lawton, J . O., Archer, I. A,, Butt, W. P . (1984) ‘The pathogenesis of idiopathic scoliosis.’ Journal of Bone and Joint Surgery, 66B, 8-15. 24. Dickson, R. A. (1988) ‘The aetiology of spinal deformities.’ Lancet, 1, 1151-1155. 25. Jones, H . H., Priest, J. D., Hayes, W. C., Tichenor, C. C., Nagel, D. A. (1977) ‘Humeral hypertrophy in response t o exercise.’ Journal of Bone and Joint Surgery, 59A, 204208. 26. Risser, J . C., Ferguson, A. B. (1936) ‘Scoliosis: its prognosis.’ Journal of Bone and Joint Surgery, 18, 667-670. 27. Rao, P. S., Gregg, E. C. (1984) ‘A revised estimate of the risk of carcinogenesis from xrays to scoliosis patients.’ Investigative Radiology, 19, 58-60.
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28. Hoffman, D. A., Lonstein, J . E., Morin, M. M., Visscher, W., Harris, B. S., Boice, J. R. (1989) ‘Breast cancer in women with scoliosis exposed to multiple diagnostic x-rays.’ Journal of National Cancer Institute, 81, 1307-1312. 29. Adair, I. V., van Wijk, M. C., Armstrong, G. W. D. (1977) ‘Moire topography in scoliosis screening.’ Clinical Orthopaedics and Related Research, 129, 165-171. 30. Adler, N. S., Csongradi, J., Bleck, E. E. (1984) ‘School screening for scoliosis: one experience in California using clinical examination and moire photography.’ Western Journal of Medicine, 141, 631-633. 31. Tachdjian, M. O., Matson, D. D. (1965) ‘Orthopaedic aspects of intraspinal tumors in infants and children.’ Journal of Bone and Joint Surgery, 41A, 223-248. 32. Rinsky, L. A. (1989) Personal communication. 33. Clarisse, P. (1974) ‘Pronostic evolutif des scolioses idiopathique mi?eures de 10” a 29” en periode de cronissance. Thesis, Universite Claude-Bernard, Lyon. Cited in Moe, J . H., Winter, R. B., Bradford, D. S., Lonstein, J. E. (1978) Scoliosis and Other Spinal Deformities. Philadelphia: W. B. Saunders. p. 58. 34. Terver, S., Kleinman, R., Bleck, E. E. (1980) ‘Growth landmarks and the evolution of scoliosis: a review of pertinent studies on their usefulness.’ Developmental Medicine and Child Neurology, 22, 675-684. 35. Fowles, J. V., Drummon, D. S., L’Ecuyer, S., Roy, L., Mohamed, T. K. (1978) ‘Untreated scoliosis in the adult.’ Clinical Orthopaedics and Related Research, 134, 212-217. 36. Rogala, E. J., Drummond, D. S., Gum, J . (1978) ‘Scoliosis: incidence and natural history. A prospective epidemiological study.’ Journal of Bone and Joint Surgery, 60A, 173-1 76. 37. Scott, M. M., Piggott, H. (1981) ‘A short-term follow-up of patients with mild scoliosis.’ Journal of Bone and Joint Surgery, 63B, 523-525. 38. Fustier, T. (1980) ‘Evolution radiologique spontanee des scolioses idiopathiques de moins de 45” en periode de crossance: etude graphique retrospective de cent dossiers du Centre de Readaptation Fonctionnelle des Massues. ’ Thesis, I’Universite‘ ClaudeBernard, Lyon. Cited in Weinstein, S. L. (1988) Adolescent Idiopathic Scoliosis: Prevalence, Natural History, Treatment Indications. (Monograph prepared by the Scoliosis Research Society and American Academy of Orthopaedic Surgeons’ Committee on the Spine.) 39. Lonstein, J . E., Carlson, J. M. (1984) ‘The prediction of curve progression in untreated idiopathic scoliosis during growth.’ Journal of Bone and Joint Surgery, 66A, 1061-1071. 40. Picault, C., de Mauroy, J. C., Mouilleseaux, B., Diana, G. (1986) ‘Natural history of idiopathic scoliosis in girls and boys.’ Spine, 11, 777-778. 41. Bunnell, W. P. (1986) ‘The natural history of idiopathic scoliosis before skeletal maturity.’ Spine, 11, 773-776. 42. Weinstein, S. L. (1986) ‘Idiopathic scoliosis: natural history of curve progression.’ Spine, 780-783. 43. Ascani, E., Bartolozzi, P., Logroscino, C. A., Marchetti, P. G., Ponte, A., Savini, R., Travaglini, F., Binazzi, R., DiSilvestre, M. (1986) ‘Natural history of untreated idiopathic scoliosis after skeletal maturity.’ Spine, 11,
784-789. 44. Miller, J. A. A., Nachernson, A. L., Schultz, A. B. (1985) ‘Effectiveness of braces in mild idiopathic scoliosis.’ Spine, 9, 632-635. 45. Lonstein, J. E. (1989) ‘Milwaukee brace treatment of adolescent idiopathic scoliosisreview of 1020 patients.’ Paper presented at the annual meeting of the Pediatric Orthopaedic Society of North America, May. 46. Dival-Beaupere, G. (1970) ‘Le reperes de maturation dans la surveillance dans scolioses.’ Revue de Chirurgie orthopedique et reparatrice de L ’Appareil Moteur (Paris), 56, 59-76. 47. Moses, L. E., Emerson, J. D., Hosseini, H. (1984) ‘Analyzing data from ordered categories.’ New England Journal of Medicine, 311, 442-448. 48. Nordwall, A. (1973) ‘Studies in idiopathic scoliosis. Relevant to etiology, conservative and operative treatment.’ Acta Orthopaedica Scandinavica, Suppl. 150, 99-124. 49. Keiser, R. P., Shufflebarger, H. L. (1976) ‘The Milwaukee brace in idiopathic scoliosis: evaluation of 123 completed cases.’ Clinical Orthopaedics and Related Research, 118, 19-24. 50. Mellencamp, D., Blount, W. P., Anderson, A . J. (1977) ‘Milwaukee brace treatment of idiopathic scoliosis. Late results.’ Clinical Orthopaedics and Related Research, 126, 47-57. 51. Carr, W., Moe, J . H., Winter, R. B., Lonstein, J. E. (1980) ‘Treatment of idiopathic scoliosis. in the Milwaukee brace.’ Journal of Bone and Joint Surgery, 62A, 599-612. 52. McCollough, N. C., Schultz, M., Javech, N., Latta, L. (1981) ‘Miami TLSO in the management of scoliosis: preliminary results in 100 cases.’ Journal of Pediatric Orthopedics, 1, 141-152. 53. Laurnen, E. L., Tupper, J. W., Mullen, M. P. (1983) ‘The Boston brace in thoracic scoliosis: a preliminary report.’ Spine, 8, 388-395. 54. Rudicel, S., Renshaw, T. S. (1983) ‘The effect of the Milwaukee brace on spinal decompensation in idiopathic scoliosis.’ Spine, 8, 385-387. 55. Basset, G. S., Bunnell, W. P., MacEwen, G. D. (1986) ‘Treatment of idiopathic scoliosis with the Wilmington brace.’ Journal of Bone and Joint Surgery, 68A, 602-605. 56. Emans, J. B., Kaelin, A., Bancel, P., Hall, J . E., Miller, M. E. (1986) ‘The Boston bracing system for idiopathic scoliosis. Follow-up results in 295 patients.’ Spine, 11, 792-801. 57. Winter, R. B., Lonstein, J . E., Drogt, J., Noren, C. A. (1986) ‘The effectiveness of the Milwaukee brace in the non-operative treatment of thoracic idiopathic scoliosis.’ Spine, 11, 790-791. 58. Blount, W. P., Moe, J. H. (1973) TheMilwaukee Brace. Baltimore: Williams & Wilkins. 59. Michel, C. R., Caton, J., Michel, F. (19877) ‘Devenir a long terme des scolioses idiopathiques ayant subi un traitement orthopedique lyonnais.’ Revue Chirurgie Orthopddique, 13, Supp. 2, 134-137. 60. Yamaguchi, Y., Asaka, Y., Chen, W. S., Tsuji, T., Yamaguchi, T., Tsuruoka, H. (1986) ‘Follow-up results of brace treatment of adolescent idiopathic scoliosis.’ Nippon Seikeigeka Gakkai Azsshi, 60, 1079-1085. 61. Green, N. E. (1986) ‘Part-timy bracing of adolescent idiopathic scoliosis. Journal of Bone and Joint Surgery, 68A, 738-742.
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72. Harrington, P . R . (1962) ‘Treatment of scoliosis. Correction and internal fixation in spine instrumentation.’ Journal of Bone and Joint Surgery, 44A, 591-610. 73. Cotrel, Y . , Dubousset, J:, Guillaumat, M. (1988) ‘New universal instrumentation in spinal surgery.’ Clinical Orthopaedics and Related Research, 227, 10-23. 74. Dickson, R . A , , Archer, I . A. (1987) ‘Surgical treatment of late-onset idiopathic thoracic scoliosis. The Leeds procedure.’ Journal 0.f Bone and Joint Surgery, 69B, 709-714. 75. Luque, E. R. (1982) ‘Segmental spinal instrumentation for correction of scoliosis.’ Clinical Orthopaedics and Related Research, 163, 192-1 98. 76. Drummond, D., Guadagnia, J., Keene, J . S., Breed, A ,, Narechania, R . (1984) ‘Interspinous process segmental spinal instrumentation.’ Journal of Pediatric Orthopedics, 4, 397-404. 77. .Moe, J . H., Purcell, G. A , , Bradford, D. S. (1983) ‘Zielke instrumentation (VDS) for the correction of spinal curvature. Analysis of results in 66 patients.’ Clinical Orthopaedics and Related Research, 180, 133- 153. 78. Ogilvie, J. W . (1988) ‘Anterior spine fusion with Zielke instrumentation for idiooathic scoliosis in adolescents.’ Orrhopedic Ciinics of North America, 19, 313-317. 79. Wojcik, A . S., Webb, J . K . , Burwell, R . G . (1989) ‘An analysis of the effect of the Zielke operation on S-shaped curves in idiopathic scoliosis The use of EVAs showing that correction of the thoracic curve occurs in its lower part: significance of the thoracolumbar spinal segment.’ Spine, 14. 625-631, 80. Edear. M. A. (1985) ‘To brace or not to brace?’ JGurnal of Bone’ and Joint Surgery, 67B, 173-174 (Editorial.)
The Tethered Cord in Myelomeningocele: Should It Be Untet hered?
1) is identical to the image of the midsagittal plane routinely obtained today by magnetic resonance imaging. LICHTENSTEIN’popularized the term ‘spinal dysraphism’ and summarized his findings by stating that these disorders may involve cutaneous, mesodermal or neural elements, singly or in combination. GARCEAU’Sdescription of the filum terminale syndrome in 19533 emphasized that progressive neurological deterioration during growth could occur and that painful scoliosis could be relieved by resection of the tight filum. More attention was focused on the occult dysraphic disorders in reports by JAMES and LASSMANin 19624 and ANDERSON in 19685. In addition to defects in bowel and bladder control, an ‘orthopaedic syndrome’ of progressive lower-extremity deformity in children was described. Salient features included motor weakness,
ONE o f the earliest pathology specimens of a ‘tethered cord in association with myelomeningocele is that of a six-weekold feimale treated by injection with Dr. Morton’s iodo-glycerine solution. This specimen, No. 145 in the Glasgow Royal Infirmary Museum, clearly depicts the low-lying conus medullaris adherent by scar tissue to the dorsal dural sac’. This anatomical lithograph by Shattock (Fig.
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