Results of Milwaukee and Boston Braces with or without Metal Marker Around Pads in Patients with Idiopathic Scoliosis

Abstract

Bracing is the non-operative treatment of choice for adolescent idiopathic scoliosis (AIS) and careful application of pads on apical segment of curve is very important for correction. Control of pads` appropriate site in brace is not easy by clinical evaluation. Therefore, we decided to compare results of braces which for better control of pads by radiographs, metal marker inserted around pads with those without metal marker. We evaluated 215 consecutive cases (182 female, 33 male) of AIS with 342 major curves from 1993 to 2003. Mean initial age was, 13.2±1.8 years (9-16) and mean duration of follow-up was, 16.1±16.4 months (0-114) that treated by 4 type of brace; 89 with type 1(Milwaukee with metal pads), 87 with type 2 (Milwaukee with simple pads), 17 with type 3 (Boston with metal pads) and 22 with type 4(Boston with simple pads). Cobb angle recorded at 5 stages (initial, best, wean, stop and final follow-up). Mean initial Cobb was 36.2˚, at stop stage, 35.2˚ and reached 38˚ at final follow-up. Overall, 21.3% improved, 42.2% were the same and 36.5% failed. Failure for braces type 1 to 4 were, 40.5%, 34%, 38% and 24% at final follow-up. A total of 59 patients (27.4%) underwent spinal fusion that for brace type 1 to 4 , was, 33, 21, 2 and 3 patients respectively. From 16 cases with initial Cobb of 50˚, at follow-up, 12 were ≥50˚ or had spinal fusion. Correction of lumbar (P=0.008) and main thoracic curves (P=0.002) was better by Boston than Milwaukee, however, In general difference between 4 types of braces was not significant and metal marker had no significant effect on results. Two important predictors of brace failure were, initial curve magnitude and brace type, but using metal marker around pads had no effect in results. It seems that bracing did not alter the natural history of scoliosis in early Risser stages with large magnitude of initial curves. Insertion of metal marker around pads is easy and cheap way that facilitate control of pad sites well, so, we recommend to use.