EARLY CHANGES IN SHOULDER BALANCE AFTER SELECTIVE ANTERIOR CORRECTION AND FUSION FOR LUMBAR SCOLIOSIS

Abstract

Some patients developed shoulder imbalance after selective anterior correction of lumbar scoliosis with spontaneous rebalances later on. We conducted this retrospective radiographic analysis study to study the effect of selective anterior correction of thoracolumbar and lumbar scoliosis on shoulder balance. Standing X-ray films of 15 patients with lumbar scoliosis operated by anterior correction at preoperative, 3, 6 & 12 months postoperative were used. Spine and shoulder balance parameters were measured. Correlations between changes in shoulder balance and spine parameters were evaluated. Shoulder height parameters showed early postoperative change from positive or neutral to negative shoulder balance, Lumbar and thoracic Cobb angles showed immediate postoperative improvement with a slight later increase contributing to shoulder rebalance mechanisms. Changes in T1 tilt was correlated to change in thoracic Cobb angle at 3 months post op. (r= 0.515 p =.049), CRCI was correlated to difference between changes in lumbar Cobb angle and changes in thoracic Cobb angle (r= 0.56 p= 0.030), close correlation between Correction change ratio and T1 tilt, FRA, CA and CPH was shown (p=0.008, 0.016, 0.011 & 0.012). Spontaneous Correction of shoulder balance after anterior correction of lumbar scoliosis is likely to occur during the first postoperative year. Flexibility of the thoracic curve was a major determinant in the shoulder re-balance, ratio between correction of lumbar curve and correction of thoracic curve may have a prognostic value in shoulder rebalance after anterior correction surgery. Clavicle angle has the best predictor for postoperative shoulder balance improvement.