Abstract
Purpose
1. To evaluate how radiological parameters change during the first 3 years following anterior endoscopic surgery. 2. To report complications encountered in this period.
Methods
Between April 2000 and June 2006,106 patients underwent an anterior endoscopic instrumented fusion. There were 95 females and 11 males. Average age was 16.1 years (range 10-46). 103 (97%) had right-sided idiopathic curves. The majority were Lenke type 1 (79%). Patients were assessed at 3, 6, 12, 24, and 36 months. 83 patients had 1 year follow-up, 69 had 2 years or more.
The following were investigated; the structural curve, instrumented curve, non-structural curves, skeletal age at operation and sagittal profile (T5-T12).
Results
The mean Cobb angle of the structural curve was 52.3 degrees. 2 months following surgery, it was 21.4 degrees, with a correction rate was 59%. There was a partial loss of correction thereafter (29.3 degrees at 3 years, P=<0.001). The instrumented curve did not change significantly. The mean post-operative Cobb angles of the proximal and distal non-structural curves (when present) at 2months were 19.6 and 19.7 degrees respectively. At 3 years they were 18.8 and 24.4. The change in the distal curve was significant (p=<0.05).
The pre-operative sagittal profile was 19 degrees. At 2 months it was 28 degrees and 31 degrees at 3 years.
Skeletal maturity at time of surgery was not found to influence the structural curve. 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.
Conclusion
Anterior endoscopic surgery is effective in restoring both sagittal and coronal balance. However, there is small loss of coronal correction in the structural curve. 11% of rods fractured, though none occurred in the 94 patients where a larger rod (5.5mm) and femoral allograft was used.
