Successful replantation of amputated facial tissues by supermicrosurgery.

BACKGROUND: Although replantation of amputated facial segments remains challenging in reconstructive surgery, it offers excellent aesthetic and functional outcomes. METHODS: From May 2004 to October 2019, 12 patients underwent replantation of amputated facial tissues by supermicrosurgery. The case details, such as the rationale for replantation, the operation method, and postoperative therapy, are described. Four cases are discussed to demonstrate the replantation of different facial parts. RESULTS: Facial tissue replantation was successful in all 12 patients without secondary surgery. The cases included the nose (1 patient), ears (8 patients), lips (2 patients), and one of the soft tissue segments surrounding the lower jaw. Venous congestion occurred in three patients who received a solitary arterial repair and were treated with bloodletting. All patients expressed satisfaction with the cosmetic and functional results at the final follow-up. CONCLUSIONS: Supermicrosurgical facial tissue replantation is a promising and effective procedure for providing patients with the best aesthetic and functional outcomes.

Temperature Field and Stress Analysis of the Heavy-Concrete Transfer-Purge Chamber of the Nuclear Power Plant.

A transfer-purge chamber (TPC) is a double-steel-plate, heavy-concrete, curved-surface composite structure composed of steel plates, heavy concrete, and shear connectors. It is an important facility in the external refueling system of a nuclear power plant (NPP), providing a safe and reliable biological shielding space for reactor refueling operations. Temperature load is one of the most important factors that must be considered in the design of NPP structures. The temperature loads experienced by the TPC during its life cycle include those encountered in both normal and abnormal operation, which are distinct. In this study, we investigated the steady state and transient-state temperature fields and stresses of a TPC structure under normal operation and after 48 h of abnormal operation, respectively, which were calculated using Abaqus finite element software and the directly coupled method. During normal operation, the temperature field of the structure shows relatively uniform changes, and the temperature gradient of the internal concrete in the direction of its thickness has a constant value of 0.245 °C/cm. At the junction between the transfer and purge sub-chambers of the TPC, under the influence of wall curvature and deformation constraints, the maximum tensile strain of heavy concrete is 8.84 × 10-3, the maximum compressive strain is 2.04 × 10-3, the peak stress of the steel plate is 98.305 MPa, and the peak stress of the stud is 306.725 MPa. After 48 h of abnormal operation, the temperatures of the inner surface of the heavy concrete of the wall, the inner steel plate of the wall, the outer surface of the heavy concrete of the wall, and the inner steel plate of the wall increased by 8.12, 8.11, 0.31, and 0.30 °C, respectively. The tensile strain of the heavy concrete of the wall increased significantly by 52.64%, and the compressive strain of the concrete increased by 67.33%, whereas the stresses of the studs and steel plates increased by only 1.57% and 6.79%, respectively. These results show that the change in the temperature field greatly influences the stress and strain on the TPC structure. As measures for mitigating the development of this unfavorable situation of temperature stress concentration, the temperature operating range should be rationally controlled or the junction structure between the transfer and purge sub-chambers of the TPC optimized accordingly. The results of our study can provide basic data for a dynamic analysis of the TPC under conditions of combined earthquake and temperature loads.

Comparison between tension band and cerclage with X-Plate and lag screws in treatment of comminuted patellar fractures.

BACKGROUND: Comminuted patellar fractures are not rare, and the ideal treatment method remains controversial. The present study was conducted to evaluate effects and compare complications of two different methods used to treat comminuted patellar fractures. METHODS: From March 2010 to August 2016, 102 cases of 34-C2 or 34-C3 comminuted patellar fractures were treated at our hospital, wherein patients received two different treatments: titanium cable tension band with cerclage method (group A) and intrafragmentary screws with X-shaped plating technique (group B). At follow-ups, articular step-off, range of motion (ROM), Lysholm scores, time of union, and complications were recorded and analyzed. Radiographic and clinical data as well as rate of complications were statistically analyzed. RESULTS: In total, 87 patients were included in the final analysis (n = 47 in group A and n = 40 in group B). No significant differences were noted in terms of cost of implant, age, gender, rate of 34-C3 fractures, rate of layered inferior pole fractures, postoperative articular step-off and union time. At 2-year follow-up, average Lysholm scores, ROM and rate of complications were (89.0 ± 4.5), (122°±12°) and (27.7%) in group A and (90.2 ± 3.9), (124°±11°) and (17.5%) in group B, respectively, with no significant differences (p > 0.05). The mean time of surgery in group B was shorter than that in group A with significant difference (p < 0.05). CONCLUSIONS: Treatment using the intrafragmentary screws and plate method for amenable comminuted patellar fractures achieved similar complication rate and favorable functional outcomes at the 2-year follow-up, which was comparable to the titanium cable tension band with cerclage method. Thus, the intrafragmentary screws and plate method is effective, safe and convenient for 34-C2/C3 comminuted patellar fractures, especially appropriate for patients with layered fragments.

Reducing Neuron Apoptosis in the Pontine Micturition Center by Nerve Root Transfer for Restoration of Micturition Function after Spinal Cord Injury.

OBJECTIVE: The rate of neuronal apoptosis increases after spinal cord injury (SCI). Anastomosing the normal nerve roots above the SCI level to the injured sacral nerve roots can enhance the functional recovery of neurons. Therefore, we evaluated the effect of sacral nerve root transfer after SCI on pontine neuronal survival. METHODS: Sprague-Dawley rats were randomly divided into three groups: Group A, reconstruction of afferent and efferent nerve pathways of the bladder after SCI; Group B, SCI only; and Group C, control group. We examined pontine neuronal morphology using hematoxylin and eosin (H&E) staining after SCI and nerve transfer. Bcl-2 and Bax protein expression changes in the pontine micturition center were quantified by immunohistochemistry. The number of apoptotic neurons was determined by TUNEL staining. We examined pontine neuronal apoptosis by transmission electron microscopy (TEM) at different time points. RESULTS: H&E staining demonstrated that the number of neurons had increased in Group A, but more cells in Group B displayed nuclear pyknosis, with the disappearance of the nucleus. Compared with Group B, Group A had significantly higher Bcl-2 expression, significantly lower Bax expression, and a significantly higher Bcl-2/Bax ratio. The number of apoptotic neurons and neuron bodies in Group A was significantly lower than that in Group B, as indicated by TUNEL staining and TEM. CONCLUSIONS: These findings demonstrate that lumbosacral nerve transfer can reduce neuronal apoptosis in the pontine micturition center and enhance functional recovery of neurons. This result further suggests that lumbosacral nerve transfer can be used as a new approach for reconstructing bladder function after spinal cord injury.

Transfer of Sciatic Nerve Motor Branches in High Femoral Nerve Injury: A Cadaver Feasibility Study and Clinical Case Report.

BACKGROUND: Femoral nerve injury causes knee dysfunction, and high femoral nerve injury is difficult to repair. OBJECTIVE: To evaluate the anatomic feasibility of transferring the sciatic nerve motor branches in high femoral nerve injury. METHODS: The femoral nerve was exposed in both lower extremities of 3 adult fresh-frozen cadavers; each branch was noninvasively dissected to its proximal nerve fiber intersection point and distal muscle entry point. The branches of the sciatic nerve were also exposed. The length, diameter, and number of myelinated fibers were measured in each femoral and sciatic nerve branch. The feasibility of tension-free direct suture between the femoral and sciatic nerve branches was evaluated. One patient was treated with transfer of a nerve branch innervating the semitendinosus muscle to the femoral nerve branch and was followed up for 18 mo. RESULTS: The diameters and numbers of myelinated fibers in the femoral nerve branches matched those of the sciatic nerve branches. In the single patient, a combined femoral nerve bundle (comprising the rectus femoris and vastus lateralis branches) was used as a graft. The branch of the sciatic nerve was sutured with the muscle branch of the femoral by using a sural nerve as a nerve graft. The knee joint straightening strength reached medical research council grade 4+. CONCLUSION: The proximal motor branches of the sciatic nerve may be transferred as donor nerves to repair high femoral nerve injury. A femoral nerve bundle comprising the rectus femoris and vastus lateralis branches may be used as the receptor nerve.

[Experimental study on crosslinked-chitosan in treatment of knee osteoarthritis in rabbits].

Objective: To study the effect of intraarticular injection of crosslinked-chitosan in the treatment of knee osteoarthritis in rabbits. Methods: Thirty-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. Results: Macroscopic 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). Conclusion: The crosslinked-chitosan can significantly improve the osteoarthritis of the rabbit knee, delay the pathological changes of osteoarthritis, and decrease the frequency of injection.

Translocation of the soleus muscular branch of the tibial nerve to repair high common peroneal nerve injury.

BACKGROUND: This study was performed to evaluate the clinical effect of translocating the soleus muscular branch of the tibial nerve to repair the deep peroneal nerve. METHODS: Eight patients were treated for high common peroneal nerve injury. The deep peroneal nerve was separated out from the common peroneal nerve if no injury occurred upon opening the epineurium of the common peroneal nerve. The soleus muscular branch of the tibial nerve was then translocated to the deep peroneal nerve. RESULTS: The average follow-up duration was 21.75 months. Electromyography revealed newly appearing electric potentials in the tibialis anterior, extensor hallucis longus, and extensor toe longus muscle at 8 to 10 months postoperatively. Four patients showed good functional recovery after surgery; functional recovery was poor in other patients. CONCLUSIONS: Translocation of the soleus muscle branch is a feasible method to treat high common peroneal nerve injuries. A full understanding of the indications for this operation is required.

A clinical comparison study of three different methods for treatment of transverse patellar fractures.

BACKGROUND: Tension bands structures are widely used to treat transverse patellar fractures. However, many implants-related complications have been reported. The purpose of this study is to evaluate effects and compare complications of three methods used to treat transverse patellar fractures, including titanium cable tension bands, compression screws with titanium cable cerclage, and X-shaped plating technique. METHODS: From January 2010 to March 2016, 120 cases of transverse patellar fracture received open reduction and internal fixation with one of three methods: titanium cable tension band (group A), compression screws with titanium cable cerclage (group B), and X-shaped plating technique (group C). Of these, 108 cases were followed for >2 years. Clinical and radiographic data were retrospectively collected and statistically compared. RESULTS: Final analysis included 108 patients (n = 38 in group A, 36 in B, and 34 in C). Reduction was satisfactory in all patients after surgery. No significant differences were noted in age, gender, time from injury to surgery, postoperative articular step-off, Lysholm score, and range of motion at 24 months among all groups. At final follow-up, 12 (31.6%) symptomatic implant complications were encountered in group A, along with 6 (16.7%) and 2 (5.9%) in groups B and C, respectively (p < 0.05). CONCLUSION: All three methods could achieve the goal of rigid fixation and early functional rehabilitation. However, the X-plate technique had the lowest risk of symptomatic implant complications and could thus be a safe and effective alternative for internal fixation of transverse patellar fractures.

Transferring of femoral nerve motor branches for high-level sciatic nerve injury: a cadaver feasibility study.

BACKGROUND: Sciatic nerve injuries cause significant disability. We propose here a novel reconstructive procedure of transferring the motor branches of the femoral nerve as donor nerves to reconstruct both the peroneal and tibial nerve function as a novel approach to treat high sciatic nerve injury. METHODS: The autopsies of donor nerves (vastus lateralis nerve branch (VLN), vastus medialis nerve branch (VMN), saphenous nerve (SAN)) and respective recipient nerves (deep peroneal nerve branch (DPN), medial gastrocnemius nerve branch (MGN), sural nerve (SN)) were conducted in six fresh-frozen lower limbs. The distance between the origin or bifurcation points of the nerves to the head of fibula and the diameter of the end at the coaptation site were measured. The feasibility of tensionless direct suturing or grafting between the donor nerves and the recipient was evaluated. Finally, the nerve end at the coaptation site was harvested for observation with toluidine blue staining and nerve fiber count. RESULTS: The mean diameter of the VMN, VLN, MGN, DPN, SAN, and SN nerves were 1.5 ± 0.1, 1.4 ± 0.1, 1.3 ± 0.1, 2.3 ± 0.1, 2.1 ± 0.3, and 1.3 ± 0.2 mm, respectively. Histological observation showed that the abovementioned six nerve bundles had a respective nerve fiber number of 392 ± 27, 205 ± 520, 219 ± 67, 394 ± 50, 308 ± 77, and 335 ± 49. A total of 5/6 specimens needed grafting for a length ranging from 5 to 15 cm to bridge the VMN-MGN, 6/6 needed a graft length of 10-20 cm for VLN-DPN bridging, and 2/6 needed a graft length of 0-4 cm for SAN-SN bridging. CONCLUSION: The study demonstrated the feasibility of the transferring femoral nerve branches to sciatic nerve branches to restore the function for sciatic injury.

[Effect of exosomes from adipose-derived stem cells on peripheral nerve regeneration].

Objective: To 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. Methods: Thirty-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. Results: Gross 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. Conclusion: The 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.

Recent Progress in the Construction of Functional Artificial Bone by Cytokine-Controlled Strategies.

OBJECTIVE: Combining artificial scaffolds with stimulatory factors to reconstruct lost bone tissues is one of the hottest research directions. The purpose of this review was to conduct a retrospective survey on the latest reports on artificial bone fabrication with functional cytokines. DATA SOURCES: The status of related scientific research from the year 2005 to 2018 was analyzed through the mode of literature retrieval in PubMed and VIP Database. The retrieval words are as follows: "bone tissue engineering," "angiogenesis," "cytokines," "osteogenesis," "biomimetic bone marrow," "sol-gel," "delivery system," and the corresponding Chinese words. STUDY SELECTION: After reading through the title and abstract for early screening, the full text of relevant studies was evaluated and those not related with this review had been ruled out. RESULTS: According to the literature retrospective survey, there were three key points for the successful construction of functional artificial bones: (1) the continuous supply of relatively low concentration of cytokines during the required period; (2) the delivery of two or more cytokines essential to the process and ensure the relatively spatial independence to reduce the unnecessary interference; and (3) supporting the early-stage angiogenesis and late-stage osteogenesis, respectively, regulating and balancing the crosslinking of both to avoid the surface ossification that would probably block the osteogenesis inside. CONCLUSIONS: The synergistic effect of both angiogenic factors and osteogenic factors applied in bone regeneration is a key point in the combined functional artificial bone. Through analysis, comparison, and summary of the current strategies, we proposed that the most promising one is to mimic the natural bone marrow function to facilitate the regeneration process and ensure the efficient repair of large weight-bearing bone defect.

[Mini locked-plate trans-carpometacarpal joint internal fixation for treating comminuted fracture of base of the fifth metacarpal].

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.

Repair of a lateral malleolus defect with a composite pedicled second metatarsal flap.

The patient was a 26-year-old man who fell while riding a motorcycle and friction led to defects in the lateral malleolus and soft tissue of the ankle. Although the wound surface healed with scarring and skin grafting, the patient had symptoms of ankle joint instability 4 months after the injury. Using a second metatarsal composite tissue flap with a dorsalis pedis artery pedicle, we repaired the soft tissue defect of the ankle and reconstructed the lateral malleolus. The head of the metatarsal bone was used to reconstruct the lateral malleolus and the flap was used to cover the wound surface. The distal fibula and metatarsus were completely healed 36 months postoperatively. The ankle had maintained stability at this time, with equal limb length and only a mild limitation of dorsal flexion in the ankle joint. The patient could walk, jog, and walk up and down stairs without limitations. There was no pain or limitation in activity at the donor site. Our findings suggest that the second metatarsal composite tissue flap with a dorsalis pedis artery pedicle is an effective option in reconstruction of the adult distal fibula.

Transfer of obturator nerve for femoral nerve injury: an experiment study in rats.

BACKGROUND: Quadriceps palsy is mainly caused by proximal lesions in the femoral nerve. The obturator nerve has been previously used to repair the femoral nerve, although only a few reports have described the procedure, and the outcomes have varied. In the present study, we aimed to confirm the feasibility and effectiveness of this treatment in a rodent model using the randomized control method. METHODS: Sixty Sprague-Dawley rats were randomized into two groups: the experimental group, wherein rats underwent femoral neurectomy and obturator nerve transfer to the femoral nerve motor branch; and the control group, wherein rats underwent femoral neurectomy without nerve transfer. Functional outcomes were measured using the BBB score, muscle mass, and histological assessment. RESULTS: At 12 and 16 weeks postoperatively, the rats in the experimental group exhibited recovery to a stronger stretch force of the knee and higher BBB score, as compared to the control group (p < 0.05). The muscle mass and myofiber cross-sectional area of the quadriceps were heavier and larger than those in the control group (p < 0.05). A regenerated nerve with myelinated and unmyelinated fibers was observed in the experimental group. No significant differences were observed between groups at 8 weeks postoperatively (p > 0.05). CONCLUSIONS: Obturator nerve transfer for repairing femoral nerve injury was feasible and effective in a rat model, and can hence be considered as an option for the treatment of femoral nerve injury.

[Biomechanics test of fixation of star-shaped six-part patellar fractures with petal-shaped poly-axial locking plate].

Objective: To 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. Methods: The 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. Results: The 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%). Conclusion: The 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.

[Experimental study of urinary center change in pons after conus medullaris injury in rats].

Objective: To observe the structural changes of urinary center and the expression of Bcl-2 after conus medullaris injury in rats brain so as to explore the possible influence factors of degeneration in brain. Methods: Thirty-six adult Sprague-Dawley rats were randomly divided into experimental group ( n=30) and control group ( n=6). In the experimental group, the conus medullaris injury model was established by cutting off the spinal nerve below L 4, and no treatment was done in the control group. The modeling operations in the experimental group were successful, and 2 rats died at 3 months and 5 months after modeling operation respectively, which may be caused by renal failure or urinary tract infection. In the experimental group, 6, 6, 6, 5, and 5 rats were killed at 1 day, 1 week, and 1, 3, 6 months after operation respectively, and 1 rat was killed at each time point in the control group. The dorsolateral tissue of the pontine tegmentum was harvested to perform HE staining and Bcl-2 immunohistochemical SP staining. Results: HE staining showed that there was no obvious difference between the experimental group and the control group at 1 day after operation, the neurons were densely packed, arranged neatly, and the nucleoli were clear; at 1 week, the space between the neurons in the experimental group were slightly widened; at 1 month, nucleus retraction in some neurons happened in the experimental group; at 3 and 6 months, the nuclei in the experimental group were more and more condensed, and even some cells disappeared. Bcl-2 immunohistochemical SP staining showed that the expression of Bcl-2 in the control group was weakly positive. The positive expression of Bcl-2 was found at 1 day after operation in the experimental group; the positive expression of Bcl-2 at 7 days after operation was significantly higher than that in the control group, and reached the peak; the positive expression of Bcl-2 decreased gradually at 1, 3, and 6 months after modeling operation, but it was still higher than that of the control group. Conclusion: The urinary center appears structure degeneration and necrocytosis after conus medullaris injury in rats brain. The elevated expression of Bcl-2 may be associated with brain tissue repair and function remodeling.

Lipoxin A4 pretreatment mitigates skeletal muscle ischemia-reperfusion injury in rats.

The aim of this study was to investigate the protective effects and underlying anti-oxidative molecular mechanism of lipoxin A4 (LA4) in rats with ischemia/reperfusion (I/R)-injured skeletal muscle. A rat model of I/R-injured skeletal muscle was obtained by subjecting rats to a 3-h ligation of the right femoral artery followed by 3 h of reperfusion. Treatment with LA4 significantly ameliorated histological damage scores in I/R-injured skeletal muscle. LA4 treatment resulted in remarkable decreases in the wet weight/dry weight ratio (W/D ratio), inflammatory response, oxidative stress, and cell apoptosis. In addition, treatment with LA4 was accompanied by a prominently enhanced nuclear accumulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and expression of heme oxygenase 1 (HO-1) in the I/R-injured skeletal muscle. However, these protective effects were reversed by zinc protoporphyrin-IX (ZnPP), a specific HO-1 inhibitor. Our study shows that LA4 may have the potential as a therapeutic agent for I/R-injured muscle tissue via activation of the Nrf2/HO-1 signaling pathway.

[Changes of endogenous Spastin expression after sciatic nerve injury in rats].

Objective: To investigate the expression change of endogenous Spastin after sciatic nerve injury in rats, and to discuss the role and significance in the peripheral nerve regeneration. Methods: Thirty-six adult male Sprague Dawley rats weighing 180-220 g were randomly divided into the experimental group ( n=30) and the control group ( n=6). Sciatic nerve compression damage model was established in the experimental group, and the sciatic nerve was only exposed in the control group. The L 4-6 spinal cord tissue was obtained to detect Spastin mRNA and protein levels by real-time fluorescence quantitative PCR and Western blot at 1, 3, 7, 14, and 28 days after operation in the experimental group ( n=6) and at 7 days in the control group. Meanwhile, the sciatic nerve at 5 mm distal to the injured site was obtained to observe the ultrastructure of the distal axon by transmission electron microscope (TEM). Results: The expression trends of Spastin gene and Spastin protein in L 4-6 spinal cord tissue of 2 groups were basically identical. In the experimental group, the expressions of Spastin gene and protein decreased at the beginning, and then increased; the expressions reduced to the minimum at 7 days after operation, and came back to the initial level at 28 days. The expression levels of Spastin mRNA and protein at 3, 7, and 14 days were significantly lower in the experimental group than the control group ( P<0.05), but no significant difference was noted between 2 groups at 1 and 28 days ( P>0.05). The expression levels of Spastin mRNA and protein at 3, 7, and 14 days were significantly lower than those at 1 and 28 days in the experimental group ( P<0.05), but no significant difference was noted between at 1 day and 28 days ( P>0.05). At 1, 3, and 7 days after operation, the myelin damage was observed by TEM; at 14 days, there were regenerating Schwann cells; at 28 days, a large number of myelinated nerve fibers were seen, which were closed to normal form. Conclusion: In the process of sciatic nerve regeneration after injury, a complex succession of changes take place in the expression of endogenous Spastin protein in rats, indicating that Spastin protein plays an important role in the process.

[A finite element analysis of petal-shaped poly-axial locking plate fixation in treatment of Y-shaped patellar fracture].

Objective: To establish the finite element model of Y-shaped patellar fracture fixed with titanium-alloy petal-shaped poly-axial locking plate and to implement the finite element mechanical analysis. Methods: The three-dimensional model was created by software Mimics 19.0, Rhino 5.0, and 3-Matic 11.0. The finite element analysis was implemented by ANSYS Workbench 16.0 to calculate the Von-Mises stress and displacement. Before calculated, the upper and lower poles of the patella were constrained. The 2.0, 3.5, and 4.4 MPa compressive stresses were applied to the 1/3 patellofemoral joint surface of the lower, middle, and upper part of the patella respectively, and to simulated the force upon patella when knee flexion of 20, 45, and 90°. Results: The number of nodes and elements of the finite element model obtained was 456 839 and 245 449, respectively. The max value of Von-Mises stress of all the three conditions simulated was 151.48 MPa under condition simulating the knee flexion of 90°, which was lower than the yield strength value of the titanium-alloy and patella. The max total displacement value was 0.092 8 mm under condition simulating knee flexion of 45°, which was acceptable according to clinical criterion. The stress concentrated around the non-vertical fracture line and near the area where the screws were sparse. Conclusion: The titanium-alloy petal-shaped poly-axial locking plate have enough biomechanical stiffness to fix the Y-shaped patellar fracture, but the result need to be proved in future.

Anatomical basis and design of the distally based lateral dorsal cutaneous neuro-lateral plantar venofasciocutaneous flap pedicled with the lateral plantar artery perforator of the fifth metatarsal bone: a cadaveric dissection.

BACKGROUND: Detailed investigation of the vasculature of the lateral aspect of the foot has rarely been presented. However, harvesting the flap in this area to cover defects of the foot and hand is highly important. Repair of soft-tissue defects at the forefoot remains a challenge in reconstructive surgery. This study explores the characteristics of the distal-based lateral dorsal cutaneous neuro-lateral plantar venofasciocutaneous flap pedicled with the lateral plantar artery perforator of the fifth metatarsal bone to establish a repair procedure for ulcers or defects in the forefoot region. METHODS: This study is divided into two parts: anatomical study and simulated operation. Thirty cadavers were utilized in the anatomical study after arterial injection. The tuberosity of the fifth metatarsal bone was used as the anatomical landmark. The lateral plantar artery perforator of the fifth metatarsal bone was identified through dissection. The perforators were dissected under a microscope. The details of the lateral plantar artery perforators, the distribution of the lateral dorsal cutaneous nerve and lateral plantar vein, the anastomosis in the lateral plantar artery perforator of the fifth metatarsal bone, the nutrient vessels of the lateral dorsal cutaneous nerve and lateral plantar vein, and other arteries of the lateral foot were recorded. The flap-raising procedure was performed on three fresh cadavers. RESULTS: The lateral dorsal cutaneous nerve originated from sural nerve, traveled obliquely downward along the anterior lateral margin of the foot, and accompanied by the lateral plantar vein after bifurcation, and was eventually distributed on the lateral aspect of the foot. The nutrifying arteries to the lateral dorsal cutaneous nerve and lateral plantar vein were present segmentally and mainly originated from the lateral plantar artery perforator of the fifth metatarsal bone. These nitrifying arteries constantly originated from the lateral plantar artery in the area of tuberosity of the fifth metatarsal, ran along the medial side of the fifth metatarsal, traveled between the fifth metatarsal bone and the lateral muscle group (the flexor digitorum brevis and the abductor digiti minimi muscles), pierced the aponeurosis, vascularized the skin of the anterior lateral plantar region, and resulted in many minute branches, which anastomosed with the lateral tarsal artery and fourth dorsal metatarsal artery. The anatomical study showed that (1) the vasculature pattern can roughly be classified into three types and (2) constant anastomoses occurred between the above-mentioned arteries in the lateral-dorsum region of the foot. CONCLUSION: A reliable large- or medium-sized neuro-venocutaneous flap with lateral dorsal cutaneous nerve, lateral plantar vein, and nutrient vessels can be raised using only the perforator of the lateral plantar artery of the fifth metatarsal bone, which is thin, is in the immediate vicinity of the forefoot, and has a reliable retrograde blood supply. This flap can be considered an alternative means to reconstruct soft-tissue defects of the forefoot.