SAGITTAL PLANE ALIGNMENT AFTER SURGERY IN SCOLIOTIC PATIENTS WITH STRUCTURAL LUMBAR CURVE

Abstract

The goal of treatment in scoliosis is not only curve correction. Restoration of normal sagittal alignment is also very important. Methods describing sagittal balance are various, they include measurement of thoracic kyphosis and lumbar lordosis, alignment of thoracolumbar junction and distance between plumb line from C7 and sacral bone.

Goals of work:

1. Evaluation the sagittal plane alignment after surgery in idiopathic scoliosis, type 5 and 6 according to Lenke classification;

2. Establishing risk factors of bad end result. Material consists of 52 patients. The mean age at the time of surgery was 16 years with the follow up time of 4 years. There were 29 patients in first group, with Lenke type 5 and 23 patients in the second group, with type 6. The Cobb angle of structural curves was in Lenke 5 group 52.5o ± 5.9 and in Lenke 6 group − 54.4o ± 8,4 in thoracic spine and 66.3o ± 11.9 in lumbar spine. Preoperative thoracic kyphosis was 20.9o ± 6.9 and 29.3o ± 15.5. Lumbar lordosis was 42.5o ± 11.4 and 35.9o ± 11.4. Thoracolumbar junction was almost straight in first group; Th12-L2 angle was 0o ± 6.7 and slight kyphotic in second group: 4o ± 8.1. All the patients underwent posterior fusion with derotational instrumentation. Radiological assessment was performed using postero-anterior and lateral radiograms. Own scale of treatment result evaluation was introduced.

Results: During control examination the thoracic kyphosis was 30.1o ± 7.8 and 27.8o ± 9.4 and lumbar lordosis was 40.3o ± 12.3 and 35.7o ± 9.9. During follow-up, the mean thoracolumbar junction angle was −4.4o ± 9.6 and −7.9o ± 9.9. Proper alignment of thoracolumbar junction was observed in 24 patients (82.8%) from first group and 21 patients (91%) from the second.

Good results in sagittal plane were noted in 22 cases (76%) from Lenke 5 group and 21 cases (91%) from Lenke 6 group. The presence of pedicle srews in lumbar spine was bound with significantly better end result. Smaller lordosis, greater probability of bad result. Kyphotic thoracolumbar junction before surgery was connected with greater risk of bad result. The level of lower end of fusion was significantly important in pre-dicticting end result.

Conclusions:

1. Own method of describing result in sagittal plane allows better assessment of sagittal balance;

2. There are several factors influencing end result in sagittal plane in scoliosis surgery;

3. The best indicator of bad sagittal result is improper alignment of thoracolumbar junction.