Spine
-
National registry cohort study. ⋯ 3.
-
A retrospective review. ⋯ 3.
-
A questionnaire survey. ⋯ N/A.
-
Retrospective cohort study. ⋯ 3.
National registry cohort study. ⋯ 3.
A retrospective review. ⋯ 3.
A questionnaire survey. ⋯ N/A.
Retrospective cohort study. ⋯ 3.