Inflammatory cytokine levels in synovial fluid 3, 4 days postoperatively and its correlation with early-phase functional recovery after anterior cruciate ligament reconstruction: a cohort study.
BACKGROUND
Synovial fluid was collected prior to and at 3 to 4 days after ACL reconstruction to investigate the correlation between inflammatory cytokine levels in the acute phase after surgery and physical functional recovery at 3 months postoperatively.


METHODS
For this purpose, 79 patients with ACL reconstruction using semitendinosus tendons were included in the study. Median days from injury to surgery were 80 days (13-291 days). Synovial fluid was obtained just before surgery and at 3 to 4 days after surgery. Physical activity of each patient was evaluated at 3 months postoperatively, and scored from 0 (hard to walk) to 5 (run). Patients able to jog (score 4) or run (score 5) were considered as the "quick recovery" group and others (scores 1-3) as the "delayed recovery" group.


RESULTS
Physical activity recovery scores in the early surgery group (preoperative period less than 60 days; Group I) were significantly better than those in the delayed surgery group (Group II). Among the cytokines tested, TNF-alpha and IL10 levels in synovial fluid were significantly higher in Group II at 3 to 4 days postoperatively, while levels of these cytokines were quite comparable preoperatively between the groups. Increased IL1-beta expression was noted in the delayed recovery group at 3 to 4 days postoperatively. In addition, levels of IL6, IL10 and IFN-gamma also tended to increase in patients with delayed recovery.


CONCLUSIONS
Delayed ACL reconstruction increases levels of inflammatory cytokines in synovial fluid after surgery and correlates with a prolonged recovery of short-period physical activity of the patients.
Department of Plastic and Reconstructive Surgery, Graduate School of Medical Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.|Department of Joint Surgery and Sports Medicine, Graduate School of Medical Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.
Makiko
M
Inoue
Department of Joint Surgery and Sports Medicine, Graduate School of Medical Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.
Takeshi
T
Muneta
Department of Joint Surgery and Sports Medicine, Graduate School of Medical Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.
Miyoko
M
Ojima
Department of Joint Surgery and Sports Medicine, Graduate School of Medical Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.
Kaori
K
Nakamura
Department of Joint Surgery and Sports Medicine, Graduate School of Medical Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.
Hideyuki
H
Koga
Center for Stem Cell and Regenerative Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.
Ichiro
I
Sekiya
Department of Plastic and Reconstructive Surgery, Graduate School of Medical Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan.
Mutsumi
M
Okazaki
Department of Cartilage Regeneration, Graduate School of Medical Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510, Japan. tsuji.orj@tmd.ac.jp.
Kunikazu
K
Tsuji
Anterior cruciate ligament; Inflammatory cytokines; Preoperative period; Recovery after surgery; Synovial fluid