3.

4.

In conclusion, neck tilt is distinct from shoulder imbalance. Clinical neck tilt has poor correlation with clinical shoulder imbalance. Clinical neck tilt grading correlated with cervical axis and T1 tilt whereas clinical shoulder grading correlated with CHD, RSH CRID and CA.

The application of S1, S2 and S2-ilium screws are feasible. The amount of medial angulation and the ideal screw length in the Asian population must be borne in mind during insertion. Right S1 screws carry higher risk of injury to the internal iliac artery when the anterior cortical penetration occurs due to the course of the iliac vessels.

4.

2.

No abstract

In PSF surgery for AIS patients, two-surgeon strategy was associated with shorter operation duration, lesser blood loss and lower incidence of allogenic blood transfusion.