This paper presents a wearable exoskeleton robot system to realize walking assist function, which oriented toward the patients or the elderly with the mild impairment of leg movement function, due to illness or natural aging. It reduces the loads of hip, knee, ankle and leg muscles during walking by way of weight support. In consideration of the characteristics of the psychological demands and the disease, unlike the weight loss system in the fixed or followed rehabilitation robot, the structure of the proposed exoskeleton robot is artistic, lightweight and portable. The exoskeleton system analyzes the user's gait real-timely by the plantar pressure sensors to divide gait phases, and present different control strategies for each gait phase. The pressure sensors in the seat of the exoskeleton system provide real-time monitoring of the support efforts. And the drive control uses proportion-integral-derivative (PID) control technology for torque control. The total weight of the robot system is about 12.5 kg. The average of the auxiliary support is about 10 kg during standing, and it is about 3 kg during walking. The system showed, in the experiments, a certain effect of weight support, and reduction of the pressure on the lower limbs to walk and stand.
Objective To investigate the feasibility of the anastomosis of the anterior branch of obturator nerve and the muscular branch of femoral nerve. Methods Five fresh frozen cadavers, including 3 males and 2 females, were included. Both of the obturator nerve, femoral nerve and their branches were dissected, then their routes and anatomical positions were observed. The diameter and the number of myelinated nerve fiber of the anterior branch of obturator nerve and femoral nerve muscular branches were measured, as well as the overlap distance between them. Results The diameter of myelinated nerve fiber of the anterior branch of obturator nerve was (3.80±1.22) mm; the number of myelinated nerve fiber was 11 358±800. The diameters of the rectus femoris branch and the medial femoral branch were (1.60±0.54) mm and (2.20±0.66) mm, respectively; the number of myelinated nerve fiber were 4 961±655 and 6 666±466. Both the diameter and number of myelinated nerve fiber were close to the anterior branch of obturator nerve. The anterior branch of obturator nerve could be directly anastomosed with each nerve branch of femoral nerve in nontension, and the overlap distance was about 30 mm. Conclusion It is feasible to repair the femoral nerve by transposed the anterior branch of obturator nerve and anastomosed with the femoral nerve muscular branches. And the rectus femoris branch and the medial femoral branch should be taken as the recipient nerve.
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 investigate the effects of exosomes from adipose-derived stem cells (ADSCs) on peripheral nerve regeneration, and to find a new treatment for peripheral nerve injury. MethodsThirty-six adult Sprague Dawley (SD) rats (male or female, weighing 220-240 g) were randomly divided into 3 groups (n=12). Group A was the control group; group B was sciatic nerve injury group; group C was sciatic nerve injury combined with exosomes from ADSCs treatment group. The sciatic nerve was only exposed without injury in group A, and the sciatic nerve crush injury model was prepared in groups B and C. The SD rats in groups A and B were injected with PBS solution of 200 μL via tail veins; the SD rats in group C were injected with pure PBS solution of 200 μL containing 100 μg exosomes from ADSCs, once a week and injected for 12 weeks. At 1 week after the end of the injection, the rats were killed and the sciatic nerves were taken at the part of injury. The sciatic nerve fiber bundles were observed by HE staining; the SCs apoptosis of the sciatic nerve tissue were detected by TUNEL staining; the ultrastructure and SCs autophagy of the sciatic nerve were observed by transmission electron microscope. ResultsGross observation showed that there was no obvious abnormality in the injured limbs of group A, but there were the injured limbs paralysis and muscle atrophy in groups B and C, and the degree of paralysis and muscle atrophy in group C were lighter than those in group B. HE staining showed that the perineurium of group A was regular; the perineurium of group B was irregular, and there were a lot of cell-free structures and tissue fragments in group B; the perineurium of group C was more complete, and significantly well than that of group B. TUNEL staining showed that the SCs apoptosis was significantly increased in groups B and C than in group A, in group B than in group C (P<0.01). Transmission electron microscope observation showed that the SCs autophagosomes in groups B and C were significantly increased than those in group A, but the autophagosomes in group C were significantly lower than those in group B. ConclusionThe exosomes from ADSCs can promote the peripheral nerve regeneration. The mechanism may be related to reducing SCs apoptosis, inhibiting SCs autophagy, and reducing nerve Wallerian degeneration.
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.