1. Florence Nightingale Hospital
SELECTIVE THORACIC FUSION IN AIS BY USING PEDICLE SCREW CONSTRUCTS (PS): WHICH FACTORS INFLUENCE SPONTANEOUS LUMBAR CORRECTION ?
Azmi HAMZAOGLU, MD
Cagatay OZTURK, MD
Ahmet ALANAY, MD
Mehmet TEZER, MD
Selhan KARADERELER, MD
Ibrahim ORNEK, MD
Istanbul Spine Center
Florence Nightingale Hospital
Istanbul-TURKEY

2. INTRODUCTION
Although selective thoracic fusion has been a gold standart treatment modality for Lenke type 1 curves, there is controversy and not much information in the literature about how much correction can safely be done without causing decompensation by using powerful PS and the factors which may affect the behaviour of lumbar curve after the surgery.

3. PURPOSE PATIENT SAMPLE
To analyse Lenke type 1 curves treated by selective fusion by using PS and to determine the critical factors which may have influenced spontaneous correction in lumbar spine.
Between 1995 and 2008, 128 (116 female and 12 male) consecutive patients with Lenke type 1 curves who underwent selective thoracic fusion by using PS constructs were included.
PATIENT SAMPLE

4. METHODS
The rule for a safe amount of correction in main thoracic curve was not to correct more than the lumbar curve magnitude in the preoperative side bending x-ray.
All patients had intraoperative under-table 35 inch x-ray to apply the rule.
Preop, postop and follow-up x-ray images were evaluated in terms of curve magnitudes and flexibility, sacral tilt (more than 2°), lower instrumented vertebra (LIV) and maturity.

5. RESULTS
Average age at the time of surgery was 15 years (range; 10 to 20) and follow-up was 50.6 (range; 24 to 136) months.
The fusion stopped at stable vertebra in 81 patients, at neutral vertebra in 31 patients and stable and neutral vertebra which were the same in 16 patients.

6. RESULTS
Average correction rates at final follow-up for thoracic curve was 79% while it was 68% for lumbar curve.
Spontaneous correction more than 5 degrees in lumbar spine was observed in 34 (26%) patients while an increase more than 5 degrees were observed in 13 (10%) patients.

7. RESULTS
Patients younger than age 14, with LIV being both stable and neutral, with lumbar flexibility more than 60%, with no sacral tilt, risser sign < 2, and female patients had more lumbar correction rates but the differences were not significant (p>0.05).

8. RESULTS
When 5° change was put as a limit, there was a tendency for deterioration in lumbar curve in patients who had sacral tilt (p=0.098).
There was no coronal plane decompensation and imbalance in any of the patients and no reoperation.

12. CONCLUSION
Correction rates over 70% can safely be obtained in main thoracic curves by avoiding correction more than the magnitude of lumbar curve in convex side bending x-ray.
Lumbar curve may deteriorate during follow-up in patients with sacral tilt.  

13. THANK YOU