Measurement of Milwaukee Brace Pad Pressure in Adolescent Round Back Deformity Treatment

Abstract

<sec><title>Study Design</title><p>In this prospective study, we measured the pad pressures of the Milwaukee brace in adolescent hyperkyphosis treatment.</p></sec><sec><title>Purpose</title><p>We evaluated the skin-brace interface forces exerted by the main pads of the Milwaukee brace.</p></sec><sec><title>Overview of Literature</title><p>A fundamental factor associated with brace effectiveness in spinal deformity is pad force adjustment. However, few studies have evaluated the in-brace force magnitude and its effect on curve correction.</p></sec><sec><title>Methods</title><p>Interface forces at four pads of the Milwaukee brace were measured in 73 patients withround back deformity (mean age, 14.04±1.97 years [range, 10–18]; mean initial Cobb angle,67.70°±9.23° [range, 50°–86°]). We used a modified aneroid sphygmomanometer to measure the shoulder and kyphosis pad pressures. Each patient underwent measurement in the standing and sitting positions during inhalation/exhalation.</p></sec><sec><title>Results</title><p>The mean pad pressures were significantly higher in the standing than in thesitting position, and significantly higher pressures were observed during inhalation compared toexhalation (<italic>p</italic>=0.001).There were no statistically significant differences between right and left shoulder pad pressures (<italic>p</italic>&gt;0.05); however, the pressure differences between the right and left kyphosis pads were statistically significant (<italic>p</italic>&lt;0.05). In a comparison of corrective forces with bracing for less or more than 6 months, corrective force was larger with bracing for less than 6 months (<italic>p</italic>=0.02). In the standing position, there were no statistically significant correlations between pad pressures and kyphosis curve correction.</p></sec><sec><title>Conclusions</title><p>In the sitting position, there was a trend toward lower forces at the skin-brace interface; therefore, brace adjustment in the standing position may be useful and more effective. There was no significant correlation between the magnitude of the pad pressures and the degree of in-brace curve correction.</p></sec>