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The important new study by Castro proposes to formulateguidelines based on evaluating outcome in the context ofthe diagnostic parameters of specific cases. The author con-cludes that curvature flexibility should be evaluated beforeinitiation of brace treatment and that in patients with rigidcurvatures the cost of bracing is not justified. This recom-mendation is based on the observation that positive resultswere obtained only in patients whose curvatures were flexi-ble at the start of treatment. Specifically, the flexibilityshould be sufficient that the correction obtained in the brace isat least 20%; patients who fail this test are excluded fromtreatment.

An alternative approach would include efforts to achieveimproved correction in the brace for patients in which thisdoes not readily occur. In other words, if a greater than 20%correction is an important predictor of success, how can weincrease the percentage of patients in this category? Thiscould include the use of exercises to increase curvatureflexibility before brace application [7], or the use of bracesthat more effectively influences curvature magnitude than athoracolumbar orthosis [3–5]. In either case, clear standardsfor diagnosis and treatment are critically needed. The paperby Castro is an important model for defining structure-function relationships in AIS, and for examining their poten-tial role in influencing outcome in the short term. The studyalso highlights the need for standardized methods for defin-ing curvature “flexibility” and other clinical parametersunderlying the variable and unpredictable long-term out-comes in children diagnosed with idiopathic scoliosis [8].

References

[1] Woolf SH. Screening for AIS—policy statement. JAMA 1993;269:2664–6.

[2] Dickson RA, Weinstein SL. Bracing (and screening)—yes or no? J BoneJoint Surg 1999;81B:193–8.

[3] Weiss HR, Weiss G, Schaar HJ. Incidence of surgery in conservativelytreated patients with scoliosis. Pediatr Rehabil 2003;6(2):111–8.

[4] Rigo M, Reiter CH, Weiss HR. Effect of conservative management onthe prevalence of surgery in patients with adolescent idiopathic scolio-sis. Pediatr Rehabil 2003;6:209–14.

[5] Maruyama T, Kitagawa T, Takeshita K, et al. Conservative treatmentfor adolescent idiopathic scoliosis—can it reduce the incidence ofsurgical treatment? Pediatr Rehabil 2003;6:215–20.

[6] Goldberg CJ, Moore DP, Fogarty EE, Dowling FE. Adolescent idio-pathic scoliosis: the effect of brace treatment on the incidence of surgery.Spine 2001;26:42–7.

[7] Dickson RA, Leatherman KD. Cotrel traction, exercises, casting in thetreatment of IS: a pilot study and prospective randomized controlledclinical trial. Acta Orthop Scand 1979;49:46–8.

[8] Weinstein SL, Dolan LA, Spratt KF, et al. Health and function ofpatients with untreated IS: a 50-year natural history survey. JAMA2003;298:559–67.

Hans-Rudolf Weiss, MDBad Sobernheim, Germany

Martha C. Hawes, PhDTucson, AZ

doi: 10.1016/j.spinee.2004.01.015

Author’s reply to Drs. Weiss and Hawes

Drs. Weiss and Hawes have suggested that patients withadolescent idiopathic scoliosis (AIS) with rigid curves betreated with exercise, then braced.

In 1984 Lonstein and Carlson [1] reported that the risk forcurve progression (RF) was equal to the Cobb measurementminus 3 times the Risser stage, divided by the patient’schronological age. The only variable in the RF formulathat can change instantaneously is the Cobb measurement.The results from the study being discussed indicated that pa-tients with AIS with flexible curves were at lower risk forcurve progression. The data do not specify whether curveflexibility, brace treatment, curve flexibility with brace treat-ment or some other unidentified factor account for the de-sired outcome of arresting curve progression. Lonstein andCarlson [1] reported that 68% of patients with Risser stage0 or 1 AIS presenting with a 20- to 29-degree Cobb mea-surement will experience curve progression. Only 22% ofRisser stage 0 or 1 patients whose initial curves were 5 to19 degrees demonstrated radiographic progression. Thus,brace treatment may have been predicated on the theoreticalreduction in risk afforded by the reduction in the curvemagnitude. For example, the RF for a 12-year-old patientwith Risser stage 1 AIS with a curve measuring 35 degreeswould be 2.6. Based on the Lonstein nomogram, 100% ofpatients with AIS with RF equal to 2.6 demonstrate curveprogression. Now assume that a thoracolumbar orthosisreduces this 12-year-old’s Cobb measurement to 15 de-grees. The calculated RF now equals 1. Does the reducedRF clinically translate into a 15% to 20% incidence of radio-graphic curve progression? Would we conclude the samething if the reduction in Cobb magnitude were seen on aside-bending radiograph?

I have often thought that an anterior thoracoscopic releasefollowed by brace treatment would be an excellent alterna-tive to fusion surgery. Brace-wear-compliant patients withAIS may benefit from this “minimally” invasive interventionregardless of whether their curves were “flexible” or “rigid.”Patients with AIS with rigid curves demonstrated radio-graphic progression and thus may have been braced “unnec-essarily.” Drs. Weiss and Hawes have suggested thesepatients with AIS with “rigid” curves may benefit from anexercise program to increase curve flexibility followed bybrace treatment. Wouldn’t patients with AIS with “flexible”curves undergoing a flexibility-brace treatment protocol sim-ilar to patients with AIS with “rigid” curves also benefit?Is curve stabilization a “good enough” result for bracetreatment? Is the enemy of good “better” or “evil”? Evil,in this case, is a treatment that may increase curve magnitudeand the likelihood of surgical intervention; better is definedas long-term clinical and radiographic correction of the de-formity as compared to the initial deformity.

Thoracoscopic anterior releases have often been used toimprove the curve flexibility at the time of fusion surgery. Ibelieve that patients with AIS would demonstrate a statisti-cally significant greater in-brace correction, after an anterior

Special Features / The Spine Journal 4 (2004) 482–489486

thoracoscopic release, than the 50% commonly reported [2–9]. I also believe that the final out-of-brace radiographs wouldbe significantly smaller, both statistically and clinically, thanthe initial in-brace radiographs when skeletal maturityoccurs. Thus, the deformity in compliant patients with AISundergoing an anterior thoracoscopic release followed bybrace treatment would be at least 50% better than the tradi-tional results reported with successful brace treatment, suc-cessful brace treatment traditionally defined as when thefinal out-of-brace curve measurements approximate the ini-tial (prebrace) curve measurements.

An essential component of the anterior thoracoscopicrelease–brace treatment protocol would be compliant bracewear. Poor brace wear compliance, 38% as reported by Karol[10], would herald significantly poorer results than bracetreatment alone. Even with 23-hour-per-day compliantbrace wear, there would be cases demonstrating acceleratedcurve progression (ie, treatment failure). Deformity progres-sion after ligamentous destabilization may follow a coursecommonly seen in patients with Marfan or other connec-tive diseases, namely rapid curve progression resistant tobrace intervention [11].

Curve rigidity, in the case of AIS, may provide resistanceand actually slow the progression of the deformity. Bracetreatment, being a form of external rigidity or resistance, triesto accomplish the same goal of curve stabilization. If exercisewere to improve the curve flexibility in a patient with AIS witha “rigid” curve, the effects may be similar in direction butsmaller in magnitude than those that would occur with ananterior thoracoscopic release followed by brace treatment.Thus, the “unnecessary” brace treatment for “rigid” curvesmay still be better than the potential “evil” that may occurwhen exercise or surgical release accelerates curveprogression.

References

[1] Lonstein J, Carlson J. The prediction of curve progression in untreatedidiopathic scoliosis during growth. J Bone Joint Surg 1984;66A:1061–71.

[2] Lonstein JE, Winter RB. The Milwaukee brace for the treatment ofadolescent idiopathic scoliosis. J Pediatr Orthop 1995;15(2):176–81.

[3] Nachemson AL, Peterson LE. Effectiveness of treatment with a bracein girls who have adolescent idiopathic scoliosis. A prospective, con-trolled study based on data from the Brace Study of the ScoliosisResearch Society. J Bone Joint Surg 1995;77A(6):815–22.

[4] Korovessis P, Kyrkos C, Piperos G, Soucacos PN. Effects of thoraco-lumbosacral orthosis on spinal deformities, trunk assymmetry, andfrontal lower rib cage in adolescent idiopathic scoliosis. Spine 2000;25(16):2064–71.

[5] Labelle H, Dansereau J, Bellefleur C, Poitras B. Three-dimensionaleffect of the Boston brace on the thoracic spine and rib cage. Spine1996;21(1):59–64.

[6] Rowe DE, Bernstein SM, Riddick MF, Adler F, Emans JB, Gardner-Bonneau D. A meta-analysis of the efficacy of non-operative treat-ments for idiopathic scoliosis. J Bone Joint Surg 1997;79A:664–74.

[7] Green NE. Part-time bracing of adolescent idiopathic scoliosis. J BoneJoint Surg 1986;68A:738–42.

[8] Price CT, Scott DS, Reed F, Sproul JT, Riddick MF. Nighttime bracingfor adolescent idiopathic scoliosis with the Charleston bending brace:long-term follow-up. J Pediatric Orthop 1997;17(6):703–7.

[9] Howard A, Wright JG, Hedden D. A comparative study of TLSO,Charleston, and Milwaukee braces for idiopathic scoliosis. Spine1998;23(22):2404–11.

[10] Karol LA. Effectiveness of bracing in male patients with idiopathicscoliosis. Spine 2001;26(18):2001–5.

[11] Sponseller PD, Bhimari M, Solacoff D, et al. Results of brace treatmentof scoliosis in Marfan syndrome. Spine 2000;25(18):2350–4.

Frank P. Castro, Jr., MDKnoxville, TN

doi: 10.1016/j.spinee.2004.01.008

To the Editor:

Schofferman et al.’s article, “Failed back surgery: etiologyand diagnostic evaluation,” [1] provides a synopsis of asymposium presented to the North American Spine SocietyAnnual Meeting in Montreal, Canada, in 2002 with a distil-lation of the material presented regarding the diagnosis offailed back surgery syndrome (FBSS). We are unable toassess if this was a peer-reviewed article or simply a synopsisof the program. However, we feel that this is a specificreview for spine surgeons and it ignores important nonsurgi-cal causes and management. The authors state that withcurrent imaging and diagnostic injections, the structural causeof failed back surgery syndrome can be elucidated in over90% of the patients. They continued and quoted that in thethree studies that look at the causes of FBSS, the mostcommon structural causes are foraminal stenosis (25% to29%), painful disc (20% to 22%), pseudarthrosis (14%),neuropathic pain (10%), recurrent disc herniation (7% to12%), iatrogenic instability (5%), facet pain (3%) and sa-croiliac joint pain (2%), among some others [2–4].

Regarding diagnostic injections, in the review of themanuscripts by Burton et al. [2], Waguespack et al. [3] andSlipman et al. [4], the three studies described, only one studyby Slipman et al. [4] used precision diagnostic injections.Slipman et al. [4] heavily focused on so-called selectivenerve root blocks, which have been shown to lack substantialdiagnostic validity [5]. Consequently, Slipman et al. [4]failed to evaluate for the presence of epidural fibrosis as acause of persistent low back pain after surgical failure. Selec-tive nerve root blocks do not differentiate among a multitudeof causes, including epidural fibrosis. Further, Burton et al.[2] and Waguespack et al. [3] have not evaluated eitherfacet joint pain or sacroiliac joint pain. It should be notedthat Manchikanti et al. [6] specifically evaluated the preva-lence of facet joint pain in post–lumbar laminectomy syn-drome patients without radicular pain in a subset of thepopulation and showed that although it was significantlyless than the control group of patients without surgical inter-vention with low back pain, the prevalence in FBSS was