From: Closed drainage versus non-drainage for single-level lumbar discectomy: a prospective randomized controlled study
Closed drainage group
Non-drainage group
p
Preoperative
59.9 ± 4.1
59.8 ± 4.2
0.736
Postoperative
32.4 ± 4.0
32.8 ± 3.9
0.348
Last follow-up
22.5 ± 3.1
22.8 ± 2.7
0.298