Drs Hohman, Ferrick, and Qvick are from the Department of Orthopaedic Surgery, State University of New York at Buffalo, Buffalo, New York.
Drs Hohman, Ferrick, and Qvick have no relevant financial relationships to disclose.
Correspondence should be addressed to: Donald W. Hohman, MD, Department of Orthopaedic Surgery, State University of New York at Buffalo, 562 Grider St, Buffalo, NY 14215 (dwhohman@buffalo.edu).
The Charleston bending brace is an alternative to the traditional full-time orthosis for the treatment of progressive scoliosis deformities. It is worn at night and imposes a supine side-bending force to correct the major scoliosis curve. Reports on the management of thoracic and lumbar curves have documented the efficacy of this nonoperative treatment method, with success reported as preventing progression of the curves in up to 60% of patients.1–3 This article describes a case of a skeletally immature girl who was managed with a Charleston bending brace and developed an over-correction of her scoliotic curve shortly thereafter.
Case Report
A 9-year-old girl presented for evaluation of a spinal deformity noted on a well child examination. A full-length standing posteroanterior scoliosis spine radiograph obtained in February 2005 demonstrated spinal asymmetry, a 10° right upper thoracic curve (apex T6), and a 7° left lower thoracic curve (apex T11). A lateral spine radiograph was normal other than hypokyphosis typical of an idiopathic curve. The patient was Risser sign 0, and the triradiate cartilage was open.
Two years later, in April 2007, the apex left lower thoracic curve measured 19°, and she remained Risser sign 0 (Figure 1). The progressive left thoracic curve was atypical, prompting spinal magnetic resonance imaging (MRI) prior to the initiation of brace treatment. Magnetic resonance imaging of the entire spine was normal other than the scoliosis. Due to the progression, a nighttime Charleston bending brace was prescribed. Radiographs in the brace demonstrated complete curve correction (Figure 2).
After 7 months of nighttime brace wear, the upper thoracic curve was 10° to the right and the lower thoracic curve was 12° to the left; she was still Risser sign 0. The patient was evaluated by clinical examination and radiographs 2 months after the start of brace wear and at 6-month intervals thereafter. Initial in-brace radiographs 2 months after starting brace wear demonstrated overcorrection of the left thoracic curve to 10° in the opposite direction, which has been previously felt to be a desirable scenario with use of a part-time Charleston bending brace.1,2 The parents and the patient confirmed that she was compliant and wore the brace for at least 28 nights per month, and for an average of 7 to 8 hours per night. After 27 months of treatment, the lower thoracic curve, which was originally convex left, was now convex right and measured 21°, indicating that the brace had maintained her correction and had overcorrected her spinal curvature (Figure 3). That radiograph was taken early in the morning, shortly after removing her Charleston bending brace. She was Risser sign 1, and brace wear was discontinued.
In March 2010, 6 months after stopping brace treatment, the patient was Risser sign 3, and the lower thoracic curve was 31° convex right (opposite original curve). A new nighttime Charleston bending brace correcting in the opposite direction of the original brace was started to treat the convex right curve. Repeat MRI of the spine was normal. Radiographs in the new brace demonstrated complete correction of the convex right lower thoracic curve. Standing posteroanterior radiographs in June 2011 demonstrated a 31° convex right curve, and she was Risser sign 4 (Figure 4). She is continuing with nighttime bracing.
Discussion
Different brace treatments have been used for the treatment of progressive scoliosis in skeletally immature individuals. The standard goal of brace treatment prevents further curve progression. To our knowledge, no other reports exist of permanent overcorrection of scoliosis with use of a brace exist.
Braces are designed to apply an external force to the trunk that will be transmitted to the spine. Several types of braces exist, each unique in design, curve treatment method, and prescribed wear schedule. The Charleston bending brace is a custom-molded spinal orthosis that attempts to hold the patient in an overcorrected position.4 The patient is positioned in a side-bending position opposite the curvature, and a corrective force is applied at the apex of the curve. The Charleston bending brace is intended to be a nighttime brace only.
Several studies have documented the efficacy of the Charleston bending brace as halting curve progression; success has been reported as the avoidance of surgical stabilization.5 Price et al2 reported the results with the Charleston bending brace of 98 patients, in which 63% of patients had excellent results and 85% had acceptable results. Curve correction was 87% for major curves and 33% for compensatory or secondary curves. Thirteen percent of curves progressed >5°, and 1% of patients required surgery.2 Trivedi and Thomson3 reported 42 patients treated with the Charleston bending brace over a period of 10 years. Patients were Risser sign 0 or 1 and were followed for a mean of 3.3 years after brace discontinuation. Average age at the start of bracing was 12.5 years, and average curve was 30.3° (range, 25°–40°). Thoracic curves had the same success as thoracolumbar and lumbar curves. Bracing was successful, preventing progression of the curves in 60% of patients. The authors concluded the Charleston bending brace was effective in preventing the progression of curves.3
Part-time or nighttime bracing with a Charleston bending brace is generally used for specific and limited indications. Although a successfully braced patient may avoid curve progression, the potential treatment failure of curve overcorrection has not been previously described. Our patient illustrates this complication. In retrospect, it may have been reasonable to discontinue use of the brace after the curve had been shown to be stable for 1 year at 10° (original convex left direction) on out-of-brace standing radiographs. We are aware of the reported potential for curve progression with the use of part-time bracing methods, prompting us to maintain the patient in the brace rather than discontinue it. Katz et al5 demonstrated that 83% of patients treated with a Charleston bending brace with curves of 36° to 45° had curve progression of >5°, compared with 43% of those treated with the Boston brace. Howard et al6 also documented that a thoracolumbosacral orthosis may be superior at preventing curve progression compared with the Charleston bending brace in adolescent idiopathic scoliosis. However, nighttime bracing offers the potential for greater compliance and increased acceptance of this treatment modality.
In the major curve, the Charleston bending brace has been shown to induce asymmetrical loading of the vertebral endplates in the coronal plane, with compressive stresses on the convex side of the curve and tensile stresses on the concave side.7 According to the Hueter-Volkmann principle, compressive stresses slow growth, and tensile stresses stimulate growth.8 The brace could apply the stimulus to modify the growth of the scoliotic portion of the spine. In a similar fashion, the Charleston bending brace may have a negative effect on the compensatory curves, causing them to progress. Clin et al7 demonstrated that asymmetrical loads of the vertebrae while in the Charleston brace could cause unwanted forces on the secondary compensatory curves, possibly pushing the compensatory curve to progression. Price et al1 recommended diligent observation of any compensatory curvatures of the spine when using the Charleston bending brace. We reported that the primary curve may also achieve a permanent overcorrected position with the implementation of nighttime bracing, and this treatment complication should be monitored for when using a hypercorrective night brace.
References
- Price CT, Scott DS, Reed FE Jr, Riddick MF. Nighttime bracing for adolescent idiopathic scoliosis with the Charleston bending brace. Preliminary report. Spine (Phila Pa 1976). 1990; 15(12):1294–1299. doi:10.1097/00007632-199012000-00011 [CrossRef]
- Price CT, Scott DS, Reed FR Jr, Sproul JT, Riddick MF. Nighttime bracing for adolescent idiopathic scoliosis with the Charleston Bending Brace: long-term follow-up. J Pediatr Orthop. 1997; 17(6):703–707. doi:10.1097/00004694-199711000-00002 [CrossRef]
- Trivedi JM, Thomson JD. Results of Charleston bracing in skeletally immature patients with idiopathic scoliosis. J Pediatr Orthop. 2001; 21(3):277–280. doi:10.1097/00004694-200105000-00002 [CrossRef]
- Schiller JR, Thakur NA, Eberson CP. Brace management in adolescent idiopathic scoliosis [published online ahead of print May 30, 2009]. Clin Orthop Relat Res. 2010; 468(3):670–678. doi:10.1007/s11999-009-0884-9 [CrossRef]
- Katz DE, Richards BS, Browne RH, Herring JA. A comparison between the Boston brace and the Charleston bending brace in adolescent idiopathic scoliosis. Spine (Phila Pa 1976). 1997; 22(12):1302–1312. doi:10.1097/00007632-199706150-00005 [CrossRef]
- Howard A, Wright JG, Hedden D. A comparative study of TLSO, Charleston, and Milwaukee braces for idiopathic scoliosis. Spine (Phila Pa 1976). 1998; 23(22):2404–2411. doi:10.1097/00007632-199811150-00009 [CrossRef]
- Clin J, Aubin CE, Parent S, Labelle H. A biomechanical study of the Charleston brace for the treatment of scoliosis. Spine (Phila Pa 1976). 2010; 35(19):E940–E947. doi:10.1097/BRS.0b013e3181c5b5fa [CrossRef]
- Roaf R. Vertebal growth and its mechanical control. J Bone Joint Surg Br. 1960; 42(1):40–59.