A case report of the treatment and care of decubitus ulcers in macaques with spinal cord injury.

Decubitus ulcers are a common spinal cord injury (SCI) complication that puts patients' lives in danger and has emerged as a more prevalent issue in modern clinical rehabilitation and care. Decubitus ulcers in humans can currently be treated in a number of different ways, but there are fewer studies on how to treat and care for decubitus ulcers in macaques. To treat a 20-year-old adult male macaque monkey with SCI and decubitus ulcers after a quarter transection of the thoracic spinal cord, a number of scientific care procedures and pharmaceutical treatments, such as dietary changes and topical or intravenous administration of medication, were carried out and continuously monitored in real-time. In comparison to the untreated group, we observed a significant improvement in decubitus wound healing in the macaques. In this article, we provide a good protocol for decubitus ulcer care after SCI and suggest that future experimental animal modeling needs to focus on issues such as care for postoperative complications.

Development of an innovative minimally invasive primate spinal cord injury model: A case report.

Spinal cord injury (SCI) animal models have been widely created and utilized for repair therapy research, but more suitable experimental animals and accurate modeling methodologies are required to achieve the desired results. In this experiment, we constructed an innovative dorsal 1/4 spinal cord transection macaque model that had fewer severe problems, facilitating postoperative care and recovery. In essence, given that monkeys and humans share similar genetics and physiology, the efficacy of this strategy in a nonhuman primate SCI model basically serves as a good basis for its prospective therapeutic use in human SCI.

Berberine-loaded MSC-derived sEVs encapsulated in injectable GelMA hydrogel for spinal cord injury repair.

After spinal cord injury (SCI), local inflammatory response and fibrous scar formation severely hinder nerve regeneration. Berberine (Ber) has a powerful regulatory effect on the local microenvironment, but its limited solubility and permeability through the blood-brain barrier severely limit its systemic efficacy. Human umbilical cord mesenchymal stem cells (hUC-MSCs)-derived small extracellular vesicles (sEVs) are natural nanocarriers with high cargo loading capacity, and can cross the blood-brain barrier. Most importantly, sEVs can improve drug solubility and drug utilization. Therefore, they can overcome many defects of Ber application. This experiment aimed to design a Ber-carrying hUC-MSCs-derived sEVs and GelMA hydrogel. Ber was loaded into sEVs (sEVs-Ber) by ultrasonic co-incubation with a drug loading capacity (LC) of 15.07%. The unhindered release of up to 80% of sEVs-Ber from GelMA hydrogel was accomplished for up to 14 days. And they could be directly absorbed by local cells of injury, allowing for direct local delivery of the drug and enhancing its efficacy. The experimental results confirmed injecting GelMA-sEVs-Ber into spinal cord defects could exert anti-inflammatory effects by regulating the expression of inflammatory factors. It also demonstrated the anti-fibrotic effect of Ber in SCI for the first time. The modulatory effects of sEVs and Ber on the local microenvironment significantly promoted nerve regeneration and recovery of motor function in post-SCI rats. These results demonstrated that the GelMA-sEVs-Ber dual carrier system is a promising therapeutic strategy for SCI repair.

Effect of generation 4.0 polyamidoamine dendrimer on the mineralization of demineralized dentinal tubules in vitro.

OBJECTIVE: Dentine hypersensitivity is a type of clinical oral disease, which is highly prevalent worldwide. Although there are many materials to treat dentine hypersensitivity, their long-term therapeutic effects are not satisfactory. Therefore, the aim of this research was to observe and identify the biological mineralization of the generation 4.0 polyamidoamine dendrimer on the demineralized dentinal tubules at different time points. DESIGN: 2mm-thick slices were obtained from the cemento-enamel junction of 36 third molar teeth that simulated the condition of sensitivity with acid etching. Slices were treated with generation 4.0 polyamidoamine dendrimer and peptide bond condensing agent, while no treatment was applied on the slices of the control group. Following immersion in artificial saliva for 2, 4, 6, and 8 weeks respectively, the mineralization condition of dentine slices was observed using the scanning electron microscope (SEM). In addition, the differences in the samples of dental slices between the 2 groups were also detected using the microhardness test. RESULTS: SEM results showed that the average diameter and density of the dentinal tubules in the experimental group were significantly lower than those in the control group (P<0.001). The microhardness test exhibited a similar result, which suggested that the microhardness of the experimental group was significantly higher than the control group (P<0.001). CONCLUSION: Generation 4.0 polyamidoamine dendrimer promotes the biomineralization of demineralized dentinal tubules. Moreover, this result also suggests that the 4.0th generation polyamidoamine dendrimer has the potential value for dentine hypersensitivity treatment.

Factors as predictors for thoracic and thoracolumbar/lumbar structural curves in adolescent idiopathic scoliosis.

BACKGROUND: Recent studies have demonstrated that the Lenke system is relatively efficient and consistent in classifying scoliosis curves. Basically, fusion should include the main curve and the structural minor curve. The criteria for defining the structural minor curve were established to help guide these decision-making process. The present study was designed to investigate predictors of the structural curve, and see whether it was possible to prevent the formation of the structural curve by interfering with influencing factors to decrease the fusion level. METHODS: Age, gender, Cobb angle, Perdriolle rotation, Risser sign and the number of vertebrae included in the curve, brace treatment, and curve location were recorded in 145 idiopathic scoliosis patients from July 2001 to January 2007. The patients were divided into two groups: structural and non-structural groups. Demographics and baseline characteristics were compared between the two groups as an initial screen. Logistic regression was used to analyze factors affecting the minor curve to become the structural curve. RESULTS: Compared with the non-structural group, the structural group had a higher Cobb angle ((51.34 ± 13.61)° vs. (34.20 ± 7.21)°, P < 0.001), bending angle ((33.94 ± 9.92)° vs. (8.46 ± 5.56)°, P < 0.001) and curve rotation ((23.25 ± 12.86)° vs. (14.21 ± 8.55)°, P < 0.001), and lower flexibility ((33.48 ± 12.53)% vs. (75.50 ± 15.52)%, P < 0.001). There was no significant difference in other parameters between the two groups. The results of the Logistic regression analysis showed that the Cobb angle (OR: 9.921, P < 0.001) and curve location (OR: 4.119, P = 0.016) were significant predictors of structural curve in adolescent idiopathic scoliosis. Every 10° change of Cobb angle increased the possibility of turning the minor curve into the structural curve by 10-fold. And thoracic curve showed, on the average, the possibility of becoming the structural curve about 4-fold more often than did the thoracolumbar/lumbar curve. CONCLUSIONS: Curve severity and curve location affect the minor curve's structural features in adolescent idiopathic scoliosis.

Using side-bending radiographs to determine the distal fusion level in patients with single thoracic idiopathic scoliosis undergoing posterior correction with pedicle screws.

STUDY DESIGN: Prospective. OBJECTIVES: To evaluate a strategy to determine the distal fusion level in posterior pedicle screw correction of single thoracic idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: No standard method for selecting the lowest instrumented vertebra (LIV) for the correction of thoracic adolescent idiopathic scoliosis with posterior all-pedicle screw instrumentations exists. METHODS: Thirty-eight patients with single right thoracic (Lenke 1A) adolescent idiopathic scoliosis undergoing posterior pedicle screw fixation were studied. The LIV was determined using guidelines based on preoperative side-bending radiographs. In brief, (1) the whole thoracic Cobb curve should be included in the fusion mass, and the LIV should not be superior to the lower-end vertebra of the Cobb measurement. (2) On the right side-bending radiographs, the LIV should be derotated to neutral in skeletally immature (Risser 0 to 3) patients and the disc immediately below the LIV must open on the left side by at least 5 degrees. (3) On the left side-bending radiographs, the disc immediately below the LIV must be open on the right side by at least 0 degree. The first segment meeting the criteria when proceeding from the lower-end vertebra caudally is chosen as the LIV. Outcomes were based on the standing radiographs. RESULTS: Minimum follow-up was 2 years. The mean preoperative thoracic curve was 48.4±9.2 degrees and 12.6±6.1 degrees at final follow-up, resulting in a mean correction of 74.7%±8.5%. The mean preoperative compensatory lumbar curve of 23.7±7.5 degrees was 6.3±4.8 degrees at final follow-up. A change in lumbar lordosis from -41.2±11.9 degrees preoperatively to -38.2±9.9 degrees at final follow-up occurred. All patients achieved coronal balance and no decompensation or adding-on phenomenon was observed. Compared with the recommended fusion end by the Harrington stable zone method, 86.9% patients were saved 1 or more motion segment. CONCLUSIONS: The method described was effective in obtaining satisfactory curve correction, adequate trunk balance, and preservation of motion segments.

Using precisely controlled bidirectional orthopedic forces to assess flexibility in adolescent idiopathic scoliosis: comparisons between push-traction film, supine side bending, suspension, and fulcrum bending film.

STUDY DESIGN: A prospective study. OBJECTIVE: To validate the effectiveness of push-traction film (PTF) in assessment of curve flexibility in adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: There is no agreement among surgeons about the most advantageous method in flexibility evaluation of scoliosis. As all methods available provide the orthopedic force from one direction and use a single torque, it is difficult for them to achieve the postoperative correction; also they could not meet the needs for different types of curves. METHODS: Precisely controlled bidirectional (push and traction) orthopedic forces were applied for curve flexibility evaluation in 31 consecutive adolescent idiopathic scoliosis patients. The correction rate (CR) of postoperation, supine side-bending, suspension, and fulcrum bending radiographs were compared with PTF in instrumented main thoracic (MT) and thoracolumbar/lumbar curves. Correlation and linear regression analyses were also been done to find the best predictor among the four methods. RESULTS: In MT group, CR of PTF was significantly higher than that of side bending (P = 0.010) and suspension (P = 0.000) but not significantly different from that of fulcrum bending (P = 0.335). In TL/L group, CR of PTF was significantly higher than that of suspension (P = 0.000), but not significantly different from that of side bending (P = 0.681) and fulcrum bending (P = 0.382). There was no significant difference between CR of PTF and postoperation in both MT (P = 0.122) and TL/L (P = 0.068) groups. Correlation and linear regression analyses showed that PTF provided the highest correlation of the four methods, with the postoperative angle in both MT (r = 0.957) and MT/L group (r = 0.779). CONCLUSION: To our knowledge, this was the first report about using precisely controlled bidirectional correction forces for curve flexibility evaluation. Although it did not achieve the best CR among the four methods studied, correlation and regression analyses confirmed that PTF was a more stable and accurate method to predict flexibility. We believe that further exploration of a more rational push-traction force ratio would help to obtain a better flexibility.

[Analysis of posterior pedicle screw-only constructs in surgical treatment of adolescent idiopathic scoliosis with a minimum three-year follow-up].

OBJECTIVE: To evaluate clinical outcomes of a group of adolescent idiopathic scoliosis (AIS) patients undergoing posterior pedicle screw-only instrumentations. METHODS: Between April 2002 and July 2006, 121 AIS patients (93 female and 28 male, average age at operation was 15.5 years which ranged from 10 to 20 years) received posterior pedicle screw-only instrumentation and fusion. All the patients were evaluated by the various-parameters measured in X-ray films before and after surgery, including Cobb angle on coronal plane, Cobb angle on sagittal plane, clavicle angle and shoulder height difference, lowest instrumented vertebrae (LIV) angulation, proximal junction kyphotic angle, the distances of central sacral vertical line (CSVL) to the LIV, to the apical vertebra and to the C(7) plumb line respectively. Complications were followed. RESULTS: An average of (11.0 + or - 1.5) levels was fused. An average coronal correction of proximal thoracic curve was 41.8%, of thoracic curve was 70.8%, of thoracolumbar/lumbar curves was 74.0%. No significant change was found in sagittal alignment. Shoulder balance and apex vertebral to central sacral line were restored well. There were no pseudoarthroses and loss of correction during the follow-ups. One adding-on, 4 proximal thoracic decompensation and 15 proximal junction kyphosis were found during the follow-ups. CONCLUSION: Posterior pedicle screw-only instrumentation and fusion has excellent radiographic and clinical results with minimal complications in the surgical treatment of AIS.

[Combination of volar buttress plate with external fixator for the distal radial fractures of type C3 caused by high-energy injuries].

OBJECTIVE: To preliminarily explore the effect of combination of volar buttress plate with external fixator for the distal radial fractures of type C3 caused by high-energy injuries. METHODS: From January 2001 to June 2007, 13 patients with distal radial fracture of type C3, 9 males and 4 females aged from 26 to 47 (average 37 years), were treated with volar buttress plate combined with external fixator plus the techniques of K-wires and bone grafting as necessary, whose effects were evaluated preliminarily through comparing the volar tilt, radial inclination, radial shortening and wrist function. RESULTS: Followed up from 7 to 29 months (average 18 months), the volar tilt, radial inclination, radial shortening and wrist function of all patients recovered remarkably. Nine patients achieved excellent and 4 good according to Sarmiento score (modified by Stewart) in the radiological manifestation, while 5 patients displayed excellent, 6 good, and 2 fair according to Gartland-Werley functional assessment system. CONCLUSION: 1) Volar buttress plate could support the valor cortex in order to prevent comminuted fragment from displacing and maintain volar tilt and to provide the volar fulcrum for external fixator. 2) External fixator, with the assistance of volar fulcrum, could maintain the volar tilt and the height of distal radius and help unload the fossa. 3) Supplemental K-wires fixation and the bone graft may assist fracture stable.

Current situation and prospect in treatment of spine and spinal cord injuries.

Spine and spinal cord injuries represent one of the most survivable, yet disabling injuries known to man. Many countries and governments have contributed great resources to study on it. With the rapid development of modern basic and clinical medicine, many effective methods can be selected to restore the mechanical stability of damaged spinal column, including several minimal invasive surgical operations. Unfortunately, up to now, there are few effective therapeutic tools for the treatment of severe spinal cord injury. But new discoveries in basic research field and progress in modern rehabilitation medicine bring us great prospects.

Magnetic resonance imaging of artificial lumbar disks: safety and metal artifacts.

BACKGROUND: This study was to investigate the safety of two types of commercially available lumbar artificial discs (CHARITE and PRODISC-L) during a magnetic resonance imaging (MRI) procedure in a 1.5-Tesla MR system, and to evaluate the size of metal artifacts on the MR image for different sequences. METHODS: A 1.5-Tesla clinical MR imaging system was used. The degree of deflection of the endplates of two artificial discs was evaluated by an angle-measurement instrument at the portals of the MRI scanner. The heating effect of the radio frequency (RF) magnetic field was evaluated by using "worst-case" imaging sequences on a human cadaver implanted with an artificial lumbar disc at the L5/S1 intervertebral disc location. The temperatures of the tissue adjacent to the implant, and of the L4/L5 intervertebral disc (used as a control) were measured, respectively, using a digital probe thermometer before and after the MRI scan sequence. A rectangular water phantom was designed to evaluate the metal artifacts of these two artificial discs under different MR imaging sequences. RESULTS: The maximal deflection angle of the endplate of the implants under a static MR field was 7.5 and 6.0 degrees, for the CHARITE and PRODISC-L, respectively. The difference between temperature rise of tissue adjacent to the two types of artificial discs and the temperature rise of the L4/L5 control location was 0.4 and 0.6 degrees C, respectively. The size of metal artifacts on images of TSE (T1/T2 -weighted), STIR and Turbo Dark Fluid sequences were relatively less than those of TSE fat saturation, Flash and SE (T1-weighted) sequences. CONCLUSIONS: The CHARITE and the PRODISC-L artificial disc do not present an additional hazard or risk to a patient undergoing an MRI procedure using a scanner operating with a static magnetic field of 1.5 T or lower. Image artifacts from the implants may present problems if the anatomical region of interest is in or near the area where these implants are located (e.g., vertebral canal at affected segment).