Fig. 1
From: Comparative study on the selection of drainage methods in posterior lumbar interbody fusion
Incision appearance and drainage devices. a, b Appearance of the surgical incision with the drainage tube placed. c Disposable ordinary drainage bag connected with a drainage tube in natural pressure drainage group. d Disposable negative pressure drainage ball connected with a drainage tube in negative pressure drainage group. e The drainage tube used in both groups, 4.7 mm in diameter, retains three lateral holes. f The inner wall of the drainage tube is provided with protrusions to prevent bending and twisting