Spine
-
A nationwide cross-sectional study. ⋯ 2.
-
A retrospective study of prospectively collected data. ⋯ 3.
-
A cross-sectional database study. ⋯ 3.
A nationwide cross-sectional study. ⋯ 2.
A retrospective study of prospectively collected data. ⋯ 3.
A cross-sectional database study. ⋯ 3.