By Keith DK Luk and Oliver M Stokes
The use of braces in the treatment of scoliosis has been depicted from as early as Hippocrates. Blount and Schmidt used the Milwaukee brace with metal struts and lateral straps and pads from 19461. The use of a brace from the pelvis to the jaw, however, led to compliance issues with some patients. Therefore, Hall and colleagues introduced the underarm total contact Boston brace in 19772, which was thought to be more acceptable to patients. While there have been developments in the method of manufacture, materials and fitting of the brace over the 35 years, the design has remained largely unchanged. At present, the Boston brace is the predominant brace in use in our centre in Hong Kong and in most centres using bracing around the world.
The evidence base
The Cochrane review of bracing3 considered only two papers to be worthy of inclusion. Only one of them was a prospective randomised trial, which compared rigid with non-rigid bracing,4 reporting 31.8% failure with elastic bracing and 4.7% failure with rigid bracing (p=0.046). The other published work consists mostly of case series or cohorts with or without control groups. The majority of these studies do not follow patients up to skeletal maturity.
It is difficult—if not impossible—to perform randomised trials5 comparing bracing with observation, or physical therapy, in the treatment of idiopathic scoliosis. For instance, neither the patients nor the surgeons would be blinded to the intervention. The subject is emotive, and frequently patients and their parents have views on the use of braces that may be influenced by treatment of family members or peers in the same locality. Most centres have a cross department policy on whether they brace, or observe—adding further problems recruiting patients to receive or be denied an intervention that they do not or do believe in. There are two ongoing randomised controlled trials (USA, Netherlands)5 that are facing issues with recruitment.
While there are papers published suggesting that bracing does not affect the natural history of the condition6, the weight of the evidence is in favour of bracing. Notably, the second paper included in the Cochrane review was a Scoliosis Research Society (SRS) multicentre prospective cohort of 240 cases and it found bracing to be successful7 with <6% progression in 74% of braced patients compared with <6% progression in 34% observed patients and 33% of electrical-stimulation managed patients (p<0.0001 or p<0.0005 if all drop-outs from the braced group were considered as failures). Additionally, a meta-analysis8 has shown that full-time bracing is better than part-time bracing, which in turn is better than the natural history. Also, this paper showed that 92% of braced patients did not progress, compared with 49% of observed and 39% of those treated with lateral electric surface stimulation.
To improve the quality and to standardise research in this area, the SRS committee on bracing and non-operative management9 published inclusion criteria for studies and assessment criteria for patients within studies. Following these criteria, measures to improve brace compliance and effect, using heat10 or pressure sensors11, have been published in an attempt to improve the quality of the evidence.
The literature is broadly in favour of bracing adolescent females with moderate curves. Superiority over casting has not been demonstrated, but full-time bracing is better than part-time and hard braces are superior to flexible braces.
Keith DK Luk is the Tam Sai Kit Chair in Spine Surgery and Oliver M Stokes is a spine fellow at the Department of Orthopaedics & Traumatology, The University of Hong Kong SAR, China.
1. Blount, et al. The Milwaukee Brace; 1973
2. Watts et al. Clin Orthop 1977; 126L: 87–92
3. Negrini, et al. https://bit.ly/QaZ1ZT
4. Wong, et al. Spine 2008; 33: 1360–65
5. Dolan, et al. J Bone Joint Surg Am 2008; 90: 2594–605
6. Goldberg et al. Spine 1993; 18: 902–08
7. Nachemson et al. J Bone Joint Surg Am 1995; 77-A: 815–22
8. Rowe et al. JBJS 1997; 79A-5: 664–74
9. Richards et al. Spine 2005; 30: 2068–75
10. Katz et al. J Bone Joint Surg Am 2010; 92: 1343–52
11. Lou et al. Med Eng Phys 2011; 33:290–94