Objective To investigate the effect of hydrostatic pressure and insulin-like growth factor 1 (IGF-1) on the expression of filamentous actin (F-actin) of temporomandibular joint disc cells in goats, and to analyze the F-actin changes of temporomandibular joint disc cells in vitro under hydrostatic pressure and IGF-1 stimulation. Methods The bilateral temporomandibular joint discs were harvested from 4 1-month-old goats, and temporomandibular joint disc cells were isolated with collagenase. Immunohistochemical staining for collagen type I and collagen type II was performed for identification. The cells at passages 2-3 were used; the experiment was divided into 4 groups according to different interventions: the cells were cultivated with complete medium in group A as control; the cells were intervened by hydrostatic pressure (0.2 MPa and 1 Hz for 3 hours) in group B, by complete medium containing IGF-1 (10 ng/mL) in group C, and by a combination of hydrostatic pressure (0.2 MPa and 1 Hz for 3 hours) and complete medium containing IGF-1 (10 ng/mL) in group D. The changes of F-actin at 24 and 72 hours after cultivation were observed by immunofluorescence staining. The cell fluorescence intensity was measured. Results The cultivated cells were identified to be temporomandibular joint disc cells by morphological observation and immunohistochemical staining. At 24 hours, fluorescence intensity of groups A and C was b and clear, with normal morphology of temporomandibular joint disc cells; F-actin arranged in disorder in group B, and F-actin was thinner with arrangement disorder in group D. At 72 hours, the F-actin arranged regularly in groups A and C; however, some F-actin became blurry with irregular arrangement, breakage, and pseudopodia in group B; and F-actin was thinner and ruptured formed in group D. With time passing, the fluorescence intensity of F-actin in groups A, B, and D had an increasing trend, showing significant differences between 24 hours and 72 hours (P lt; 0.05); but there was no significant difference between 24 and 72 hours in group C (t=0.284, P=0.781). At 24 hours, fluorescence intensity of F-actin was highest in group C and was lowest in group B, showing significant difference when compared with groups A and D (P lt; 0.05). At 72 hours, fluorescence intensity in groups B and D was significantly lower than that in groups A and C (P lt; 0.05), but there was no significant difference between groups B and D, and between groups A and C (P gt; 0.05). Conclusion Hydrostatic pressure may cause the F-actin breakage and rearrangement of temporomandibular joint disc cells, and IGF-1 can up-regulate the F-actin expression. Such effects may be correlated with the biological behavior of the temporomandibular joint disc cells.
Objective To evaluate the effectiveness of arthroscopic reconstruction of posterior cruciate ligament (PCL) with embedded “tibial tendon bolt” fixation. MethodsThe clinical data of 32 patients who underwent arthroscopic reconstruction of PCL using embedded “tibial tendon bolt” fixation through the tibial “8”-shaped tunnel between February 2012 and April 2016 were analyzed retrospectively. There were 23 males and 9 females, aged 15-57 years (mean, 39.9 years). The causes included traffic accident injury in 12 cases and sports injury in 20 cases. The clinical manifestations were swelling of knee joint, tenderness of knee joint space, and (+) Ⅲ degree in posterior drawer test; McMurry test (+) in 13 cases, valgus stress test (+) in 8 cases, Lachman test (+) in 9 cases, and Dial test (+) in 2 cases. The preoperative Lysholm score was 18.8±10.9, the International Knee Documentation Committee (IKDC) score was 18.0±15.2, and the detection value of KT-1000 was (14.34±2.73) mm. The time from injury to operation was 8-225 days, with a median of 11 days. Results All 32 patients were followed up 25-36 months, with an average of 26.4 months. The patients had no tenderness of joint space, and the McMurry tests were all (−). At last follow-up, the Lysholm score and IKDC score were 90.2±2.4 and 87.2±6.2, respectively, which were significantly improved when compared with preoperative ones (t=−38.400, P<0.001; t=−27.190, P<0.001). The results of posterior drawer test were (−) in 21 cases, (+) Ⅰ degree in 9 cases, and (+) Ⅱ degree in 2 cases. At 1 and 2 years after operation, the detection value of KT-1000 were (5.56±2.28) mm and (5.87±1.78) mm, respectively, which were significantly improved when compared with preoperative values (P<0.05). ConclusionThe application of arthroscopic reconstruction of PCL using embedded “tibial tendon bolt” fixation through the tibial “8”-shaped tunnel is an effective, simple, and safe surgical procedure.