The Radiological Changes and Complications During the First Three Years Following Endoscopic Scoliosis Surgery

Hay, Douglas, Adam, Clayton J., Izatt, Maree T., Askin, Geoffrey N., & Labrom, Robert D. (2007) The Radiological Changes and Complications During the First Three Years Following Endoscopic Scoliosis Surgery. In Williamson, Owen (Ed.) Annual Scientific Meeting of the Spine Society of Australia, 20-22 April, 2007.



Doug Hay, Clayton Adam, Maree Izatt, Robert Labrom, Geoffrey Askin.

Paediatric Spine Research Group, Brisbane, Australia.

INTRODUCTION Anterior endoscopic scoliosis surgery has become an alternative to open or posterior correction of thoracic scoliosis. This technique has the potential advantage of saving levels fused without the morbidity of open thoracotomy. The study aim was to investigate radiological changes during the first 3 years following surgery.

METHOD All anterior endoscopic instrumented fusions were included. Patients were assessed at 3, 6, 12, 24, and 36 months. None were lost to follow-up. The following parameters were investigated; the structural curve, instrumented curve, non-structural curves, rib hump, skeletal age and sagittal profile. The correction rate and fulcrum flexibility were calculated from pre-operative bending films. The FBCI (Fulcrum Bending Correction Index) was calculated. Complications were reported. Statistical comparisons between pre-operative and post-operative time periods were performed using t-tests.

RESULTS There were 106 consecutive patients (95 female). The median age was 14.6 years (range 9.9-46.5). 103 (97%) had right-sided curves. 99 (93%) were idiopathic curves. The majority were Lenke type 1 (79%)). The mean pre-operative Cobb angle of the structural curve was 52.3 degrees (30-80). 2 months following surgery, it was 21.4 degrees (6.0-46). The mean correction achieved was 59% (30%-87%). A partial loss of correction occurred in a linear fashion thereafter and at 3 years it was 29.3 degrees (P=<0.001). The instrumented curve did not change significantly over the 3-year postoperative period. The mean preoperative Cobb angle of the proximal and distal non-structural curves were 28.5 and 32.3 degrees. Postoperatively the figures were 19.6 and 19.7 degrees respectively. At 3 years, they were 18.8 and 24.4. The change in the distal curve between 2 months and 3 years was significant (p=<0.05). The mean preoperative rib hump was 17 degrees, improving to 6 degrees at the 2-month follow-up. There was no significant change at 3 years. The mean preoperative Cobb angle of the sagittal profile was 19 degrees (13-40). 2 months following surgery, it was 28 degrees and 31 degrees at 3 years. Skeletal maturity at time of surgery was not found to influence the structural curve. The FBCI was 1.17. There were 12 fractured rods. All were 4.5mm rods and all but 2 were using rib autograft. There were 8 cases of proximal screw pullout.

DISCUSSION The initial correction rate of the structural curve was in keeping with previous studies. Postoperatively, there was a small, though significant, loss of coronal correction. This occurred at the caudal end beyond the instrumented curve. The distal non-structural curve when present increased postoperatively presumably to balance the structural curve. The proximal non-structural curve did not change in the postoperative period. This was reflected clinically by a constant rib hip correction. This surgical technique restored and held thoracic kyphosis. There was a significant complication rate. We now use a 5.5mm rod and femoral head allograft to avoid rod fracture. The FBCI was 1.17. This technique is effective in achieving correction equal to that of the preoperative bending films. Anterior endoscopic surgery is effective in restoring both sagittal and coronal balance. However, there is small loss of correction in the structural curve. This technique should be considered an alternative to open or posterior correction methods.

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ID Code: 7495
Item Type: Conference Paper
Refereed: Yes
Additional URLs:
Subjects: Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > CLINICAL SCIENCES (110300) > Orthopaedics (110314)
Divisions: Past > QUT Faculties & Divisions > Faculty of Built Environment and Engineering
Current > Institutes > Institute of Health and Biomedical Innovation
Current > QUT Faculties and Divisions > Science & Engineering Faculty
Deposited On: 10 May 2007 00:00
Last Modified: 24 Jun 2017 14:31

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