Pulmonary Function in Patients with Adolescent Idiopathic Scoliosis 25 Years After Surgery or Start of Brace Treatment

Kerstin Pehrsson, MD, PhD;
Aina Danielsson, MD;
Alf Nachemson, MD, PhD
Sahlgrenska University Hospital– GÖTEBORG, SWEDEN

PURPOSE:
To determine the long–term outcome of pulmonary function in patients treated by posterior fusion or brace treatment and identify risk factors for reduction of pulmonary function.

METHODS:
A consecutive group of patients treated by posterior surgery or brace 25 years ago was investigated. 90% attended a clinical follow–up. Vital capacity (VC), forced expiratory volume (FEV1) and total lung capacity (TLC) was determined in 251 patients before treatment, 18 months after surgery in 141 patients and 25 years after surgery or start of brace treatment (n=110). The results were corrected for loss of height due to scoliosis. VC was calculated in % predicted according to height and age. Cobb angles were measured. Smoking habits were recorded and an age and sex match control group was also examined.

RESULTS:
Mean VC increased from 3.1 liters (1) before surgery to 3.51 after surgery and 3.61 at present follow–up after 25 years. VC in % predicted increased from 67 before surgery to 73 after surgery and 84 (p<0.001) at present follow–up. In the brace treated patients the VC was 3.41 before and 3.81 at present follow–up and VC in % predicted 77% and 89% (p<0.001) respectively. FEV1 and TLC also increased. VC in % predicted was 103% in the control group. Mean Cobb angle at present follow–up was 40 degrees in both surgically and brace treated patients. The present results of VC or FEV1 did not correlate to Cobb angles or smoking habits.

CONCLUSION:
Patients treated by posterior fusion or brace treatment gradually increase their pulmonary function long time after treatment. In this patient group VC was 85% of predicted normal 25 years after surgery or brace treatment. We could not identify any risk factors for the reduction of pulmonary function.