OBJECTIVE: To investigate the influence of tissue engineered tendon on subgroup of T lymphocytes and its receptor in Roman chickens. METHODS: The flexor digitorum profundus of the third toes of right feet in 75 Roman chickens were resected and made 2.5 cm defects as experimental model. They were randomly divided into five groups according to five repair methods: no operation (group A), autograft (group B), fresh allograft (group C), polymer combined with allogenous tendon cells (group D), derived tendon materials combined with allogenous tendon cells (group E). The proliferation and transformation of lymphocytes and contribution of CD4+, CD8+, CD28 and T cell receptor (TCR) were detected to study the immune response. RESULTS: The CD4+, CD8+ and TCR of group D and E were increased slightly than that of group B after 7 days, while after 14 days, those data decreased gradually and no significant difference between tissue engineered tendon and autografts (P gt; 0.05), and there was significant difference between fresh allograft and tissue engineered tendon (P lt; 0.05). Lymphocytes transformation induced by conA also showed no significant difference between tissue engineered tendon and autografts (P gt; 0.05). CONCLUSION: Tendon cells are hypoantigen cells, there are less secretion of soluble antigen or antigen chips dropped out from cells. Tissue engineered tendon has excellent biocompatibility.
Objective To review the research and del ivery methods of growth factors in tendon injuries, and to point out the problems at present as well as to predict the trend of development in this field. Methods Domestic and international l iterature concerning growth factors to enhance tendon and l igament heal ing in recent years was extensively reviewed and thoroughly analyzed.? Results Cell growth factor could promote tendon heal ing, improve the mechanical properties as well as reduce the adhesion postoperatively. The use of transgenic technology mediating cell factors to promote tendon repair shows its advantages in many ways. Conclusion The growth factors play a vital role in tendon heal ing. Reasonable treatment of growth factors through direct appl ication or gene transfer techniques is of great value for the heal ing process.
OBJECTIVE To improve the clinical result of repair on flexor tendon injury, and recover the defected finger function in children as far as possible. METHODS From January 1990 to October 1997, 12 cases with flexor tendon injury were repaired by microsurgical technique, sutured by modified Kessler method with 3/0 or 5/0 nontraumatic thread and followed by invering suture of the gap edge with 7/0 or 8/0 nontraumatic thread after debridement. Appropriate functional practice was performed postoperatively. RESULTS All the defected fingers were healed by first intention. Followed up 6 months to 1 year, there was excellent in 7 cases, better in 4 cases, moderate in 1 case and 91.67% in excellent rate according to the TAM standard of International Hand Committee. CONCLUSION The important measures to improve the clinical result in children’s flexor tendon injury are prompt and accurate diagnosis and repair of the injured tendon by microsurgical technique, and effective postoperative functional practice.
One of the most difficult problems on tendon surgery is adhesion formation during the process of tendon healing, which causes functional interference. This pathophysiologic pcocess is closely related to the ways of tendon nourishment and types of tendon healing. In order to understand whether the sutured tendon couldheal without blood circulation, the process and types of tendon healing in the synovial fluid were studied by in vivo culture modle. Flexor digitorum profundus (FDP) segments from the front paw of 50 New Zedland white rabbits were cut inthe middle and sutured with microsurgical technique, and then, preserved in thesynovial cavitied of both knees of the rabbits. After 1, 2, 4, 6 weeks, the specimens from the synovial cavities were studied by gross observation, light microscope, scanning and transmission electron microscope, and biochemical determination. The results showed that the tendon which was nourished by synovial fluid not only could survive, but also could heal. Healing of the tendon was completed by activation and proliferation of both peritendon cells and cells in the tendon.The healing could be devided into 3 periods: malnutrition period (less than 1 week), reparative period (2-4 week) and rebuilding period (more than 4 week).
OBJECTIVE: The review the effect of cytokines on repair of tendon injury and the relevant mechanism. METHODS: By broadly consulting recent issues about cytokines involved in tendon repair, a variety of cytokines with effects in repairing injured tendon was made and the possible mechanisms were summarized, with unsolved problems discussed. RESULTS: There were many cytokines participated in the procedure of tendon repair, among which insulin-like growth factor (IGF-1), transforming growth-beta 1 (TGF-beta 1) played significant roles. Most of the relevant researches were limited in experimental study in vitro. CONCLUSION: Cytokines possibly can accelerate tendon repair and show great potentials in future clinical application.
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.
Through dissection of 12 fresh finger specimens, the anatomy of the distal part of dorsal aponeurosis and its function was closely observed. A direct reparative procedure of the terminal tendon by using tendon flap graft was deseribed for the treatment of chronic mallet finger deformity. Correction of deformity, restoration of active motion of DIP and avoidance of residual pain were observed in three clinical cases.
Objective To explore a rapid histological preparation method to observe morphology and composition distribution of tendon collagen fascicle and endotendinum. Methods Taking porcine superflexor tendon of foot as an example, tendons were sliced into sections with 6 μm by frozen section technology, after which general observation of the section integrity was carried out. After fixed with 10% neutral buffered formalin and performed with HE staining, the tissue integrity and ice crystal formation were observed under microscope. Sections were then divided into 5 groups by different methods of dyeing. Group A: Priodic acid-Shiff (PAS) staining; group B: Masson staining; group C: reticular fibers staining; group D: immunohistochemical and immunofluorescent staining of type Ⅲ collagen; group E: the sections were baked at 65℃ for 10 minutes and stained with Masson. The composition distribution of tendon collagen fascicle and endotendinum in different groups were observed. Results From general observation, the frozen section of tendon tissue was complete and continuous. Although the tissue integrity in the tendon sections could be seen and no ice crystal was formed, the composition distribution could not be identified by HE staining. The entire tendons in groups A, B, and C were dyed, and the composition distribution of collagen fascicle and endotendinum could not be identified. The endotendinum in group D was stained weakly positive for type Ⅲ collagen alone, and the two components were differentiated dyed but the contrast was not obvious. In group E, the collagen fascicle and endotendinium were differentiated dyed and the two components in tendon tissue were clearly visible. Conclusion The morphology and the composition distribution of tendon collagen fascicle and endotendinum can be characterized rapidly and accurately, using a combination of baking at 65℃ for 10 minutes and Masson staining after porcine superflexor tendons were sliced by frozen section technology.
OBJECTIVE: To investigate a cryophylactic agent (CPA) to protect tissue engineered tendon (TET) in deep low temperature. METHODS: Sixty-four BALB/C inbred nude mice were chosen, which included 4 as blank control group, left sides of 60 as experimental group and their right sides as control group. Transformed human embryonic tendon cells of the 54th passage and artificial materials of carbon fiber (CF) and polyglycolic acid (PGA) were co-cultured in vitro to construct TET. TET was frozen in liquid nitrogen with four kinds of CPA (groups A, B, C, and D) for 2 months. They were thawed quickly and transplanted into hind limbs of nude mice to repair the defects of Achilles tendon, which was 5 mm in length and 65.7% of total Achilles tendon. In control group, no cryopreservation treatment was taken. The morphological, histological, ultrastructure, and immunohistochemistry examinations were made and short tandem repeat loci were detected 2, 4, 6, 8, and 12 weeks later. RESULTS: In the experimental group, the morphological properties of tendon cells resumed gradually and the capability of synthesizing collagen enhanced by degrees. Tendon cells survived and could secret type I collagen and there was less difference between experimental and control groups 12 weeks after transplantation. In group A, vacuole in mitochondrion of tendon cell decreased, tendon cell arranged in order and abundant collagen fibers were found and linked. CONCLUSION: The cryopreservation agent in group A can protect TET in deep low temperature.
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.