Conservative treatment for pediatric lumbar spondylolysis to achieve bone healing using a hard brace: what type and how long?

Object. Various kinds of trunk braces have been used to achieve bone healing in cases of pediatric lumbar spondylolysis. However, the optimal brace for achieving bone healing is unclear. The purpose of the present study was to determine in what types of spondylolysis bone healing can be achieved and how long it takes. Methods. In this prospective study, 63 pars interarticularis defects (spondylolysis) among 37 patients who were younger than 18 years (mean 13.5 +/- 2.7 years) were treated using a hard brace. The youngest patient was 8 years old. Based on the results of CT scanning, the lyses were classified into 3 categories: early, progressive, and terminal defects. Progressive defects were further divided into 2 types according to STIR MRI findings: those with high signal intensity at the adjacent pedicle and those with low signal intensity (that is, a normal appearance). A hard brace, such as a molded plastic thoracolumbosacral orthosis, was used to immobilize the trunk. Approximately every 3 months, CT scanning was performed to evaluate bone healing until approximately 6 months. Results. The union rates were 94%, 64%, 27%, and 0% for the early, progressive with high signal intensity, progressive with low signal intensity, and terminal defects, respectively. It was noted that no terminal defect was healed using conservative treatment. The mean time to healing among the defects that showed bone healing was 3.2, 5.4, and 5.7 months for the early, progressive with high signal intensity, and progressive with low signal intensity groups, respectively. Conclusions. Patients with early-stage defects are the best candidates for conservative treatment with a hard brace because more than 90% of such cases can be healed in 3 months. (http://thejns.org/doi/abs/10.3171/2012.2.SPINE10914)