Objective To investigate the hemostasis of thermosensitive chitosan hemostatic film. Methods Fifty adult Sprague Dawley rats, male or female and weighing 190-210 g, were made the models of liver injury. The models were randomly divided into 5 groups (n=10) depending on different hemostatic materials. The incision of the liver was covered with the hemostatic materials of 2.0 cm × 1.0 cm × 0.5 cm in size: thermosensitive chitosan hemostatic film (group A), chitosan hemostatic film (group B), cellulose hemostatic cotton (group C), gelatin sponge (group D), and no treatment (group E), respectively. The bleeding time and bleeding amount were recorded. After 4 weeks, the incisions of the liver were observed with HE staining. Results Gross observation showed better hemostatic effect and faster hemostatic time in groups A, B, and C; group D had weaker hemostatic effect and slower hemostatic time; group E had no hemostatic effect. The bleeding time and bleeding amount of groups A, B, C, and D were significantly lower than those of group E (P lt; 0.05). The bleeding time and bleeding amount of groups A, B, and C were significantly lower than those of group D (P lt; 0.05), but no significant difference was found among groups A, B, and C (P gt; 0.05). The liver cells of group A had milder edema and ballooning degeneration than other 4 groups through histological observation. Conclusion The thermosensitive chitosan hemostatic film has good hemostasis effect on the liver incision of rats.
Objective To evaluate the effectiveness of open reduction and trans-carpometacarpal joint internal fixation with mini locked-plate for treatment of comminuted fracture of base of the fifth metacarpal. Methods Between July 2015 and December 2017, 8 cases of comminuted fractures of base of the fifth metacarpals were treated with open reduction and trans-carpometacarpal joint internal fixation with mini locked-plate. There were 7 males and 1 female with an age of 19-45 years (mean, 32.5 years). The causes of injury included 2 cases of hitting hard objects while clenching fist, 6 cases of falling injury. There were 2 cases of subluxation of fifth carpal joints and 1 case of dislocation. The time from injury to operation was 1-5 days (mean, 3.5 days). The stability of fracture ends could not be maintained by preoperative evaluation without over articular fixation or short time over articular fixation. Postoperative complications and fracture healing were observed, and hand function was evaluated at last follow-up according to the total active motion (TAM) recommended by the Branch of Hand Surgery of Chinese Medicine Association. Results All the incisions healed by first intention without complications such as wound infection, cutaneous necrosis, tendon or nerve injury. All the patients were followed up 6-18 months (mean, 12 months). All fractures healed with the healing time of 12-16 weeks (mean, 13 weeks). Within 4 months after operation, all patients were able to return to pre-injury job. At last follow-up, according to the TAM recommended by the Branch of Hand Surgery of Chinese Medicine Association, the results were excellent in 7 cases, good in 1 case, with the excellent and good rate of 100%. Conclusion Applying of mini locked-plate for treatment of comminuted fractures of base of the fifth metacarpal, of which cannot obtain stable fixation through non-transarticular or short-time transarticular fixation, can achieve satisfactory functional results with very few complications through trans-carpometacarpal joint approach, thus the procedure can be used as an alternative operation scheme.
ObjectiveTo compare the biomechanical difference between petal-shaped poly-axial locking plate and tension band wire cerclage in fixing star-shaped 6-part patellar fractures in cadaver model, and provide the experimental data for clinical use.MethodsThe paired 12 knee specimens from 6 human cadavers were randomly divided into 2 groups (the control group and the test group) after a star-shaped 6-part patellar fracture model was established. The specimens were weighted, and the control group was fixed with tension band wire cerclage and the test group was fixed with petal-shaped poly-axial locking plate. The specimens were connected to CMT5105 biomechanics test machine by a customized fixture, the total fracture gap of patellar fracture blocks was measured before testing. The knee extensor load test was performed to record the extensor load of knees at 90° flexion to extension. Then the anti gravity physiological knee extension process at 90° flexion was stimulated according to the knee extensor load. The cyclic times until failure and the total fracture gap of patellar fracture blocks after failure were recorded.ResultsThe specimens weight and the total fracture gap of patellar fracture blocks before testing between 2 groups had no significant difference (t=0.410, P=0.690; t=0.650, P=0.530). In the biomechanical test, there was no significant difference of knee extension load between 2 groups (t=0.490, P=0.638). The total fracture gap after failure in test group was significantly smaller than that in control group (t=3.026, P=0.013), and the cyclic times until failure in test group was significantly more than that in control group (t=2.277, P=0.046). The failure reasons in control group were all the wires slipped off the Kirschner wires, while the failure reasons in test group were the screws pulled out from the upper pole in 5 cases (83.3%) and from the lower pole in 1 case (16.7%).ConclusionThe petal-shaped poly-axial locking plate has better biomechanical stiffness to fix the star-shaped 6-part patellar fractures when compared with tension band wire cerclage method. However, this type of fracture is a serious comminuted type, and the early excessive activity still carries the risk of displacement.
ObjectiveTo study the effect of intraarticular injection of crosslinked-chitosan in the treatment of knee osteoarthritis in rabbits.MethodsThirty-two New Zealand white rabbits were randomly divided into 4 groups (groups A, B, C, and D; 8 rabbits in each group). The knee osteoarthritis models were prepared by anterior cruciate ligament transection in the left hind in groups A, B, and C. At 4 weeks after operation, the rabbits were received intraarticular injection of 0.6 mL crosslinked-chitosan in group A, 0.3 mL chitosan (once per 2 weeks, for twice) in group B, and 0.3 mL saline (once per 2 weeks, for twice) in group C. The rabbits in group D were treated with sham operation in the left hind, and received intraarticular injection of 0.3 mL saline (once per 2 weeks, for twice). At 8 weeks, the macroscopic observation, histological examination (HE staining, Safranin-fast green double staining, and Mankin score), scanning electron microscopy (SEM) observation, and immunohistochemical staining of collagen type Ⅱ were performed.ResultsMacroscopic and SEM observations showed that the cartilage in group D was basically the same as normal and better than that in groups A and B, and the abrasion of cartilage in group C was the most serious. The histological observation results in groups A and B were slightly similar and better than those in group C, but not up to the structure of group D. The macroscopic score and Mankin score of groups B and C were significantly higher than those of group D (P<0.05), and there was no significant difference between group A and group B (P>0.05). Immunohistochemical staining results showed that the collagen type Ⅱ positive percentage of chondrocytes was significantly higher in group D than that in groups B and C, and no significant difference was found between group A and group B (P>0.05). ConclusionThe crosslinked-chitosan can significantly improve the osteoarthritis of the rabbit knee, delay the pathological changes of osteoarthritis, and decrease the frequency of injection.