In order to compare the immunogenecity and biological properties of homologous tendon grafts after treatment from different methods of freezing, tendons from chickens received repeated freezing-thawing treatment or ultra-low-temperature treatment, and then, the post-treatment tendons were preserved in liquid nitrogen for 3 months before transplantation. The autogenous tendon transplantation was served as the control. It was found that in the group of repeated freezing-thawing treated tendons, the tendon cells all died and while in the ultra-low temperature treated tendons the active rate of tendon cells was 92.5% +/- 3.4%, and the histological observation showed that transplantation of frozen tendons would result in extensive infiltration of inflammatory cells in the grafted tendons and the peritendinous adhesion was serious than that of the autografts. The active flexion function, hydroxyproline levels and the biomechanical analysis showed no significant differences between the repeated freezing-thawing treated homografts and the ultra-low-temperature treated homografts, and that the autografts was definitely superior to the homografts. The conclusions were: (1) Transplantation of the homologous tendons from the two different methods of freezing could receive considerable success and there was no significant difference between them; (2) Transplantation of frozen homologous tendon graft might give successful result which was probably due to the preservation of the cellular activity of the tendon cells following freezing treatment and elimination of the antigen presenting cells in the tendon as well, and (3) Although the cellular components of the tendon were damaged and the antigenicity of the tendon was lowered, it did not necessarily mean that homologous tendon graft would always be successful in transplantation.
This paper reported the method tendon reconstruction on dogs. Using the pedicled fascio-tendon graft, the flexor tendon system was constructed, and comparative study was made between the vascularized fascio-tendon graft and the free fascio-tendon graft by means of oxygen tension measurement, stereology, histology and ultra-mieroseoppy. The results showed: 1. vascularized graft changed the course of healing of the conventional graft into a simplified tendon stump healing course which shortened the healing time, ahd reduced the formation of peritendinous.2. the fascia tissue could be transformed into the synovial-like tissue6 weeks postopertively under the stimulation of gliding pressure of the tendon.It was conclude that this was a new and better method in reconstructing the severely damaged flexor tendon system.
In order to study the influence of severity of tendon injury on the morphology of collagen fibers during healing process of extensor tendons, 40 female Wistal rats were used for investigation. The rats were divided into 2 groups. Transection of the tendon of extensor digitorum longus was performed in one group, while partial section of the same tendon was performed in the other group. Morphometric analysis was undertaken on the 15th, 30th, 60th and 90th day after operation. The result was that there was no significant difference between the two groups both in distribution and diameter of collagen fibers on the 15th and 30th days (P gt; 0.05). However, there was significent difference between those on the 60th and 90th days (P lt; 0.05). It was concluded that the severity of the tendon injury could influence the morphology of collagen fibers during the late stage of tendon healing.
Objective To explore the effects of exogenous basic fibroblast growth factor (bFGF) on insheathed tendon healing and adhesion formation. Methods Ninety Leghorn chickens were randomly divided into 3 groups (groups A, B and C), 30 animals for each group, and the right third digitorum longus tendon of the chicken was transected to make defect models. In group A, the tendon was sutured in situ after transection. In group B, the tendon was sutured after 0.6 μl fibrin sealant (FS) was applied at repair site. In group C, the tendon was sutured after 0.6 μl FS mixed with 500 ng bFGF was appliedat repair site. At 1, 2, 4 and 8 weeks after operation, the tendons of 6 chickens in each group were harvested for morphological and histological evaluation. Six specimens of each group was obtained for biomechanical test at 8 weeks. Results The gross observation showed that the differences of grading of tendon adhesion were not significant between groups A, B, and C 8 weeks after operation(Pgt;0.05). Histological evaluation showedthat there were no significant differences in fibroblast counting and the content of collagen fibers between groups A and B(P＞0.05). The angiogenesis, fibroblast proliferation and collagen production in the sheath, epitendon and parenchyma at repair site in group C occurred earlier and were more than those in groups A and B, showing significant differences (Plt;0.05). The biomechanical tests showed that the gliding excursionof the tendon in group A, B and C were 3.44±0.43、3.51±0.56 and 2.84±0.42 mm respectively; the work of flexion were 14.87±1.72、14.08±1.85 and 20.62±3.52 Nmm respectively; the ultimate tensile strength of the tendon was10.34±1.45，11.26±1.83 and 15.02±2.20 N respectively; showing no significant differences between groups A and B(Pgt;0.05), but showing significant differences between group C and groups A, B(Plt;0.05). Conclusion The exogenous bFGF at tendon repair site can facilitate insheathed tendon healing, but also increase the tendon adhesion formation.
Objective To review the recent researches of basic fibroblast growth factor (bFGF) in tendon tissue engineering. Methods Recentoriginal related literature was extensively reviewed and analyzed. Results bFGF played an important role in establishing standard tendon tissue engineering cell lines, inducing the compound and analysis of extracellular matrix, enhancing interactions between cells and extracellular matrix and accelerating tissue engineering materials’ neovascularization. Conclusion The progresses in increasing endogenetic bFGF expression, controlling the release of exogenous bFGF and improving the bioutilization of bFGF has laid foundation for wider use of bFGF in tendon tissue engineering.
Objective To make a comparison for the change of maximum tensile intensity and stiffness of a whole implant that is placed into bone tunnel with various lengths tendon, by using beagle dog’s autogenous flexor tendons to reconstruct anterior cruciate l igament (ACL). Methods Sixty male beagle dogs were included in the experiment (weighting 13-16 kg). Three dogs were used for intact flexor tendon of both knees (normal control group), 3 dogs for the intact ACL andfemur-graft-tibia complex (auto control group) and 54 dogs (108 knees) for models of reconstructed ACL (6 experimentalgroups according to different lengths of tendon: 5, 9, 13, 17, 21 and 25 mm in the bone tunnel). The tensile intensity and stiffness were measured after 45, 90 and 180 days separately after operation. Results In the normal control group, the maximum tensile intensity of the intact flexor tendon was (564.15 ± 36.18) N, the stiffness was (59.89 ± 4.28) N/ mm. In the auto control group, the maximum tensile intensity of the intact ACL was (684.75 ± 48.10) N, the stiffness was (74.34 ± 6.99) N/ mm, all ruptured through the intra-articular portion of the graft. The maximum tensile intensity of femur-graft-tibia complex in the auto control group was (301.92 ± 15.04) N, the stiffness was (31.35 ± 1.97) N/mm. After 45 days of operation, all failure occurred at the tibial or femoral insertion site. After 90 days of operation, 24 of the breakpoints were scattered in tendon-bone junction, 12 (3 in 17 mm group, 5 in 21 mm group, 4 in 25 mm group) ruptured through the intra-articular portion. After 180 days of the operation, all breakpoints were distributed inside joint of the implant. The maximum tensile intensity and the stiffness were ber in 17, 21 and 25 mm groups than in 5, 9 and 13 mm groups after operation (P lt; 0.05). Conclusion Tendon with 17 mm length, which will be implanted into bone tunnel, is an appl icable index, in reconstruction of ACL by autogenous tendons.
OBJECTIVE: To evaluate the function of injured hand after repair of finger stump and reconstruction of digit tendon attachment in finger amputation. METHODS: From 1992 to 1998, 20 cases with amputation of the 2nd to the 5th fingers were investigated, of which reconstruction of digit tendon attachment in 10 cases (group A) and routine operation without reconstruction of digit tendon attachment in other 10 cases (group B). After 6 months of operation, the tension test, fatigue test the sense of stability in motion and the perimeter of forearm in injured hand and the corresponding healthy hand were compared. RESULTS: The differences were remarkable (P lt; 0.01) between group A and group B in the tension test of injured finger, the fatigue test, the sense of stability in motion and the perimeter of injured arm. CONCLUSION: The digit of injured finger should be reconstructed in finger amputation in order to furthest maintain the function of injured hand.
In order to understand the influence of the free tendon graft and the tendon transfer on their blood supply, histological and biochemical changes during healing following repair of the damaged tendon after the alteration of the nourishing environment, an experiment was carried on 36 New Zealand white rabbits. In the front paws of the rabbits, the free tendon graft was sutured in the tendon defect of flexor of the fourth toe and the flexor tendon of the third toe was transferred to the second toe to reconstr...
Objective To investigate the effects of bone morphogenetic protein 2 (BMP-2) on the chondrogenic differentiation of human Achilles tendon-derived stem cells (hATDSCs) in vitro. Methods Achilles tendon was harvested from a voluntary donor with acute Achilles tendon rupture. And nucleated cells were obtained by digesting with collagenase and were cultured to the 3rd passage. The flow cytometry was used to measure the immunophenotyping; and Oil red O staining, alizarin red staining, and Safranin O/fast green staining were used to identify the adipogenic differentiation, osteogenic differentiation, and chondrogenic differentiation, respectively. The hATDSCs pellet was cultured in complete culture medium with (experimental group) or without recombinant human BMP-2 (rhBMP-2) (control grup) for 3 weeks. Chondrogenic differentiation of hATDSCs was evaluated by HE staining, Safranin O/fast green staining, and immunohistochemical staining for collagen type II; and the mRNA expressions of SOX9, collagen type II, and Aggrecan were detected by real-time fluorescence quantitative PCR. Results Primary hATDSCs cultured in vitro showed clonal growth; after cell passage, homogeneous spindle fibroblast-like cells were seen. The cells were positive for CD44, CD90, and CD105, while negative for CD34, CD45, and CD146. The results were positive for Oil red O staining at 3 weeks after adipogenic differentiation, for alizarin red staining at 4 weeks after osteogenic differentiation, and for Safranin O/fast green staining at 3 weeks after chondrogenic differentiation. After hATDSCs were induced with rhBMP-2 for 3 weeks, pellets formed in the experimental group, and the size of pellets was significantly larger than that in the control group; the results of HE staining, Safranin O/fast green staining, and immunohistochemical staining for collagen type II were all positive. The results of real-time fluorescence quantitative PCR showed that the mRNA expressions of SOX9, collagen type II, and Aggrecan in the experimental group were significantly higher than those in the control group (P lt; 0.05). Conclusion BMP-2 can promote proteoglycan deposition and induce chondrogenic differentiation of hATDSCs in vitro. The effect of BMP-2 on hATDSCs might provide a possible explanation for histopathological changes of tendinopathy.
Objective To compare the effect of decimeter wave with sodium hyaluronate product (SHP) on preventing and treating peritendinous adhesion and promoting tendon heal ing. Methods Totally 96 healthy male white 6-month-old Leghorn chickens weighing (2.24 ± 0.07) kg were randomized into group A ( decimeter wave therapy group, n=32),in which decimeter wave therapy was appl ied 1 to 21 days after operation at a frequency of 915 MHz, a power of 8 W, radiation distance of 10 cm, for 10 minutes once per day; group B (SHP group, n=32), in which 5 mL and 1.2% SHP was appl ied; and group C (control group, n=32), in which injury received no treatment. The III and IV toes of left feet of all chickens were made into tendon injury model. The general condition of animal was observed after operation; gross and histological observations were made 7, 10, 14, 18, 21 and 28 days after operation, and the biomechanical analysis was done 14 and 28 days after operation. Results Operative incision healed well, no infection and death occurred. Peritendinous adhesions in groups A, B were looser, and tendon heal ing was better than that of group C 14 and 28 days after operation. More fibroblasts with active metabol ism and more collagen formation in groups A, B than that in group C. The Pmax of group A was better than that of group B 14 and 28 days after operation (P lt; 0.05); the δmax of group A was better than that of group B 18 and 21 days after operation (P lt; 0.05), and the W0 of group A was better than that of group B 18, 21 and 28 days after operation (P lt; 0.05). There was no significant difference between group A and group B at the other time points. Conclusion Topical decimeter wave therapy and appl ication of SHP after flexor tendon repair can promote intrinsic heal ing, meanwhile they can prevent the adhesion of tendon and reduce extrinsic heal ing. Decimeter wave therapy can improve the qual ities of tendon’s wound heal ing.