Points of Consensus: Scheuermann's Kyphosisetiology

Thomas M. Gavin, CO

ETIOLOGY

We recognize the definition of Scheuermann's disease as a condition of unknown cause that produces an increased spinal kyphosis with true structural changes. To differentiate true Scheuermann's disease from postural roundback, we recognize the criteria described by Sorensen,7 namely, that three adjacent vertebrae must each be wedged at least 5°. Orthoses can be useful in treating this disease for the more typical vertebral apices of T7-T9, and also for subtype apices of the lower thoracic, thoracolumbar, or lumbar spine.

TREATMENT GOAL

The orthotic treatment goal for Scheuermann's kyphosis is to serially diminish the size of the curve to a degree that will provide permanent correction of the deformity. We concur with the Scoliosis Research Society's position: "Observation is done for deformity of less than 60° and orthotic treatment for curves between 60° and 80° if the patient is skeletally immature." Curves larger than 80° may benefit from other therapies (eg, Risser cast) as a precursor to orthotic treatment.

DISCONTINUATION OF ORTHOSIS USE

For thoracic curves, the goal should be to reduce the kyphosis to an angle of less than 50° before discontinuation of orthosis use. Post-treatment deterioration (increase) has been demonstrated in the literature, so the amount of kyphosis ideally should be decreased beyond a size that may otherwise be considered acceptable. For example, it may be necessary to reduce a curve to 40° to 45°, as documented by an out-of-orthosis film when skeletal maturity is thought to be achieved, to obtain a long-term result of 50° to 55° of kyphosis.

THE ROLE OF PHYSICAL THERAPY

Unlike the treatment of scoliosis, active correction of a kyphosis by the patient's volitional control within an orthosis, especially with a Milwaukee-style orthosis, is thought to play a role in the correction of the deformity. For this reason, the role of a physical therapist to instruct the patient on methods to strengthen the extensors of the spine may be beneficial.

RESEARCH PRIORITIES

Increase our understanding of the complete role of physical therapy as an adjunct to orthotic treatment of Scheuermann's kyphosis.
Better understand the efficacy of bracing Scheuermann's kyphosis with a Milwaukee-style orthosis versus a molded, thermoplastic TLSO. By extension, there needs to be a better understanding of active versus passive in-orthosis correction in both designs.
There needs to be a better understanding of the limits of orthotic efficacy with respect to varying degrees of deformities (eg, both Cobb angles and curve location).