Curve Progression at Least Ten Years after Maturity in Patients with Moderate Adolescent Idiopathic Scoliosis - A Prospective Comparison of Observation or Brace Treatment

Purpose: To perform a long term follow up regarding curve changes of the Swedish patients included in the original study.

Methods: Sixty-five patients were treated with observation only as the intention to treat and 41 patients received Boston brace treatment. The majority of the patients attended a clinical and radiological follow-up, including (re)measurement of curve sizes (Cobb). Patients having undergone surgery after maturity were identified through search of the mandatory national database for performed surgeries.

Results: The age at FU for all patients was mean 32 years and follow-up time 16.0 years after completed treatment/maturity. So far, 79% of the patients have been followed.

The group with observation as the intention to treat had a Cobb value of 30.1° at base-line. Twenty-three (35.4%) patients had a curve increase >= 6° during the original study and were counted as failures. Of those, thirteen (20.0%) patients underwent brace treatment and six underwent surgery before maturity.

Curve size now was mean 35.9° for observed only patients, 50% had increased >= 6°, but only four had a curve size beyond 45°.

Patients brace treated originally now had a curve size of mean 31.8°, 48% had increased by >= 6° and one patient had a curve size beyond 45°.

No patients had undergone surgery after maturity.

Conclusion: Six patients in the observed group and none in the brace group were operated during adolescence and no one during the mean 16 year follow-up.

Patients observed only have not increased their curves more often than patients initially brace treated. The number of patients with a curve size beyond 45° does not differ between these groups either.