STUDY DESIGN: In vivo study OBJECTIVES: To evaluate variations in matrix metalloproteinase (MMP) expression levels according to the disc location in patients with sequestrated lumbar disc herniation. SUMMARY OF LITERATURE REVIEW: MMPs are considered to be the major catabolic enzymes in the intervertebral disc. MMPs have been known to be the primary mediators of extracellular matrix (ECM) degradation, to play major roles in disc degeneration by changing the collagens and the extracellular matrix, and to be involved in the processes of apoptosis and autoresorption of herniated disc materials by inducing inflammatory cytokines. MATERIALS AND METHODS: The sequestered and contained disc materials were removed from seven patients with sequestered lumbar disc herniations. The materials from the contained discs were classified into group 1 and those of the sequestered discs into group 2. Immunochemistry tests were conducted for the tissues of both groups. The expression levels of MMP-1, 3, and 13 were checked using a fluorescence microscope. The amount of expression of each MMP was calculated using the percentage of expressed cells and analyzed statistically. RESULTS: In the histological study, increased expression of MMP-1, 3, and 13 was found in group 2. In the statistical analysis after the quantification of MMP expression, the expression of all MMPs was found to have increased significantly in group 2 (p<0.05). CONCLUSIONS: The increased expression of MMP-1, 3, and 13 indicated that the inflammation and degeneration processes, and the spontaneous resorption by the surrounding tissues were more active in the sequestered disc group than in the contained disc group.
Apoptosis ; Collagen ; Cytokines ; Extracellular Matrix ; Fluorescence ; Humans ; Immunochemistry ; Inflammation ; Intervertebral Disc ; Intervertebral Disc Degeneration ; Intervertebral Disc Displacement ; Matrix Metalloproteinases

Purpose: Total knee arthroplasty (TKA) is a clinically efficacious surgical option for end-stage knee osteoarthritis.However, TKA increases the risk of serious bleeding and blood transfusion. The objective of this study was to evaluate the difference in postoperative blood loss in groups subjected to 3 h of clamping and non-clamping and determine the variations in rate and amount of transfusion after TKA between the two groups. Materials and methods: Propensity score matching of the group subjected to 3-h drain clamping (43 patients;September 2015 to April 2016) and the control group (43 patients; before initiating the clamping method) was performed in patients undergoing unilateral primary posterior stabilized TKA. The two groups were compared. We measured the total drained blood volume until the drain was removed 48 h after surgery, and we compared the preoperative levels of hemoglobin and hematocrit with levels observed on days 1 and 2 after surgery. We also determined the blood transfusion rate and volume as well as the occurrence of clamping-associated complications. Results: In the group subjected to 3-h drain clamping, the mean volume of total drained blood was significantly lower than in the control group (333.8 ± 190.2 mL vs. 839.9 ± 339.8 mL, P <0.001). There was no significant difference in total blood loss between the two groups (1226.9 ± 488.1 mL vs. 1127.1 ± 424.5 mL,P = 0.315), but the hidden blood loss was significantly higher in the 3-h drain clamping group than in the control group (893.1 ± 487.7 mL vs.294.7 ± 531.8 mL, P <0.001). Both the transfusion rate and amount in the 3-h drain clamped group were higher than in the control group but were not statistically significant (30.2% vs. 37.2%, P = 0.494 and 269.8 ± 483.8 mL vs.316.3 ± 158.2 mL,P = 0.648, respectively). No significant differences in complications, including deep vein thrombosis, pulmonary thromboembolism, and oozing, were noted between the two groups (all,P = 1.000). Conclusions The 3-h drain clamping method after primary TKA using posterior stabilized implant reduced the loss of postoperative drained blood. However, hidden blood loss was significantly higher in the 3-h drain clamping group; as a result, there were no differences in total blood loss and transfusion rate. The clamping method did not significantly alter the complication rate.