ABSTRACT
BACKGROUND:To improve local microenvironment and reduce local scars is conducive to peripheral nerve regeneration that promotes nerve function recovery.OBJECTIVE:To evaluate the effect of fresh amniotic membrane on the regeneration of tinjured peripheral nerve.METHODS:Sixty healthy Sprague-Dawley rats were randomly divided into three groups (n=20 per group) after constructing a model of sciatic nerve injury of the unilateral leg. In group A, the nerve was wrapped with fresh human amnion at the anastomosis end after the repair of nerve. In group B, the nerve was wrapped with biofilm at the anastomosis end after the repair of nerve. In group C, no treatment was conducted after the repair of nerve (blank control). The effects were evaluated by anatomical observation, light microscope observation, immunohistochemical detection (2, 4, 8, 12 weeks after surgery), transmission electron microscope observation, axon imaging analysis, action potential detection, and sciatic nerve function index (4, 8, 12 weeks after surgery).RESULTS AND CONCLUSION: (1) Gross observation. The amniotic membrane and biofilm were absorbed partialy at postoperative 2 weeks, mostly at postoperative 4 weeks and completely at postoperative 8 weeks. In the groups A and B, the nerve was adhered slightly and loosely to the surrounding tissues, with a fair range of motion. In the group C, the nerve was tightly adhered to the surrounding tissues, with a poor range of motion. (2) Observation under light microscope. The nerve regeneration was better in the groups A and B than group C at 2, 4, 8, 12 weeks postoperatively. (3) Observation under electron microscope. Regenerated nerve fibers were rarely seen and lamelar structures were unclear in the three groups at 4 weeks postoperatively. Then, increased regenerated nerve fibers, thickened myelin sheath, clear lamelar structure and enlarged axon diameter were found in the groups A and B compared with the group C at 8 and 12 weeks postoperatively. (4) Immunohistochemical detection. The expression and distribution of S-100 protein in the groups A and B were better than those in the group C. (5) Axon image analysis. Groups A and B were superior to the group C in the diameter of myelinated nerve fibers, thickness of myelin sheath and number of regenerated nerve fibers. There was a significant difference by statistical analysis (P < 0.05). (6) Electrophysiological examination. Shorter latency period, higher amplitude and faster nerve conduction velocities were observed in the groups A and B compared with the group C (P < 0.05). (7) The sciatic function index. The sciatic function index in group A or B was significantly higher than that in group C (P < 0.05). To conclude, the human amniotic membrane can reduce adhesion between the damaged nerve and surrounding tissues, and prevent scarring at the anastomosis end. In addition, it promotes the regeneration of nerve fibers, increase axon diameter and myelin sheath thickness, and ease inflammatory and immune responses at the neural incision.
ABSTRACT
BACKGROUND:Experiments have demonstrated that biological membranes can be usedtorecon struct thetendon she athandin hibit exogenou shealing of thetendon.Therefore,the semembrane sprovide a good bed for tendon gliding and reduce tendon adhesion. OBJECTIVE:To compare the effectsof acelular amniotic membrane and medical membraneagainst tendon adhesion during the repair oftendon sheath defects. METHODS:ToesIIIfrom the bipeds of 66 leghorns were chosen to prepare tendon injury and tendon sheath defect models, which were randomly divided into three groups (n=22 per group). Amnion group were repaired with acelular amniotic membrane, medical membrane group with absorbable membrane, and control group had no treatment on tendon sheath defects. Gross, histological and biomechanical tests of each group were performed at 2, 4, 8, 12 weeks after surgery. RESULTS AND CONCLUSION:At 12 weeks after surgery, in the amniotic membrane and medical membrane groups, the tendon sheath formed completely, and the tendon healed well, with no adhesion, but in the control group, there was serious tendon adhesion. At 8 weeks after surgery, the number of synovial cells in the false sheath was highest in the amniotic membrane group sequentially followed by the medical membrane group and control group. In the amniotic membrane group, the rough endoplasmic reticulum expanded highly and secreted exuberantly in the matrix, while in the control group, the synovial cells presented with messy arrangement, and expanded vacuoles in the matrix were weaker than those in the other two groups. At 12 weeks after surgery, fibroblasts were arrayedtidily in layerwith dense structure in the medical membrane and amniotic membrane groups;but in the control group, fibroblasts were distributed disorderly with loose structure. Tendon sliding distance and total flexor toe angle in the amniotic membrane and medical filmgroups were significantly larger than those in the control group (P < 0.05),butthere was no significant difference between the medical membrane and amniotic membrane groups. Additionally, the maximum tensile fracture strength had no significant difference among three groups at 12 weeks after surgery. These results indicate that both amniotic membrane and medical membrane can markedlyprotect the tendon from exogenous healing and adhesion.
ABSTRACT
Objective To measure the normal sagittal and coronal diameters of thumb and great toe distal phalanx bottom by ultrasonography. Methods One hundred and twenty volunteers' sagittal and coronal diameters of thumb and great toe distal phalanx bottom were measured by ultrasonography. The measurements was analysed by the statistical method. Results The thumb and great toe distal phalanx bottom showed hyperechoic zone,clear boundary with the adjacent fascia and tendon tissue showed low echo area at cross section by high frequency ultrasound. The sagittal diameters of thumb distal phalanx bottom was (8. 07 ± 0. 67)mm in men, while that of great toe distal phalanx bottom was (8. 34 ± 1. 02) mm( t = 1.73, P =0.86).The coronal diameters of thumb distal phalanx bottom was (11.61 ±0.89)mm in men, while that of great toe distal phalanx bottom was (14. 25 ± 0. 84)mm( t = 16. 77, P = 0. 00). The sagittal diameters of thumb distal phalanx bottom was (7. 52 ± 0. 62) mm in women, while that of great toe distal phalanx bottom was (7. 72 ± 0. 67) mm( t = 1. 72, P =0. 14). The coronal diameters of thumb distal phalanx bottom was (10.94 ± 0.97) mm in women, while that of great toe distal phalanx bottom was (13. 51 ±0. 75) mm( t =16.21, P = 0.00). Conclusions The normal sagittal and coronal diameters of thumb and great toe distal phalanx bottom measured by the ultrasonography can guide the operation of wrap-around flap of a great toe with phalanx ungual for thumb II degree defect reconstruction.