Bone Fracture Healing under the Intervention of a Stretchable Ultrasound Array.

Ultrasound treatment has been recognized as an effective and noninvasive approach to promote fracture healing. However, traditional rigid ultrasound probe is bulky, requiring cumbersome manual operations and inducing unfavorable side effects when functioning, which precludes the wide application of ultrasound in bone fracture healing. Here, we report a stretchable ultrasound array for bone fracture healing, which features high-performance 1-3 piezoelectric composites as transducers, stretchable multilayered serpentine metal films in a bridge-island pattern as electrical interconnects, soft elastomeric membranes as encapsulations, and polydimethylsiloxane (PDMS) with low curing agent ratio as adhesive layers. The resulting ultrasound array offers the benefits of large stretchability for easy skin integration and effective affecting region for simple skin alignment with good electromechanical performance. Experimental investigations of the stretchable ultrasound array on the delayed union model in femoral shafts of rats show that the callus growth is more active in the second week of treatment and the fracture site is completely osseous healed in the sixth week of treatment. Various bone quality indicators (e.g., bone modulus, bone mineral density, bone tissue/total tissue volume, and trabecular bone thickness) could be enhanced with the intervention of a stretchable ultrasound array. Histological and immunohistochemical examinations indicate that ultrasound promotes osteoblast differentiation, bone formation, and remodeling by promoting the expression of osteopontin (OPN) and runt-related transcription factor 2 (RUNX2). This work provides an effective tool for bone fracture healing in a simple and convenient manner and creates engineering opportunities for applying ultrasound in medical applications.

Lumbar foraminal stenosis was associated with back pain and leg pain: epidemiological evidence from a population-based cohort.

OBJECTIVES: To determine the characteristics of lumbar foraminal stenosis (LFS) on magnetic resonance (MR) images and their association with back pain and radiating leg pain in a population-based sample of Chinese subjects. METHODS: This study was an extension of the Hangzhou Lumbar Spine Study, a cross-sectional study focusing on back pain and lumbar spine MR imaging findings. Questionnaire data, including demographics, lifestyle, occupational exposures, back pain and radiating leg pain were included. On lumbar spine MR images, disc degeneration was assessed using Pfirrmann grade and Modic changes were evaluated. Using Lee's scale, the L3-S1 intervertebral foramina were evaluated, with grade 2-3 representing substantial LFS and grade 0-1 no LFS. Characteristics of LFS were noted, and associations of LFS with back pain and radiating leg pain were examined. RESULTS: Among the 644 study subjects, 141 (21.9%) had at least one LFS, and its occurrence was associated with greater age (OR = 1.93 for each 10 years, p < 0.001). Substantial LFS was associated with the presence of back pain (OR = 1.92, p = 0.001) and the intensity of the worst back pain (Coef = 8.30, p < 0.001) over the past 12 months, and disabling back pain during their lifetime (OR = 2.25, p < 0.001). Substantial LFS was also associated with leg pain (OR = 14.27, p < 0.001), with a sensitivity of 75.7% for the presence of radiating leg pain and a specificity of 81.4%. CONCLUSION: Substantial LFS on MR images was a common age-related degenerative phenotype in adults, and appears to be an independent risk factor for back pain and leg pain.

Conservative Treatments for Lumbar Disc Herniation at L3-4 or L4-5 Were More Likely to Fail When Ipsilateral Foraminal Stenosis Was Present at the Caudally Adjacent Segment.

BACKGROUND: Conservative treatments are important in lumbar disc herniation (LDH), but predictors for poor outcomes are unclear. METHODS: Consecutive patients with unilateral single-level LDH at L3-4 or L4-5 were enrolled. Baseline clinical data were collected, and lumbar spine magnetic resonance imaging was evaluated. Foraminal stenosis was evaluated using Lee's approach and further categorized as absence (grade 0 and 1) or presence (grade 2 or 3). Each patient underwent conservative treatments (oral meloxicam and dexamethasone, corset, back extension exercise, physiotherapy, and manual therapy) for 6 weeks. Conservative treatments were defined as failed if a patient underwent surgery within 6 weeks or reported poor recovery at 6-week follow-up. Multivariate logistic regressions were used to examine the associations of failed conservative treatments with baseline characteristics and magnetic resonance imaging findings. RESULTS: The study included 222 patients (mean age 45.5 ± 9.8 years). Of patients, 48 (21.6%) had concurrent ipsilateral foraminal stenosis at the caudal segment, and conservative treatments failed in 39 (17.6%). At baseline, patients with LDH and caudal foraminal stenosis were older (50.79 ± 6.14 years vs. 44.10 ± 10.13 years, P < 0.001), had greater leg pain (7.06 ± 1.17 vs. 6.39 ± 1.40, P = 0.003), and had a higher rate of positive straight leg raising test (54.2% vs. 33.3%, P = 0.008) than patients without caudal foraminal stenosis. In multivariate regression, failure of conservative treatments was associated with positive straight leg raising test (odds ratio 2.26, P = 0.046), and caudal foraminal stenosis (odds ratio 3.20, P = 0.007). CONCLUSIONS: In the presence of caudal foraminal stenosis and positive SLR test, conservative treatments were more likely to fail in patients with LDH.

[Bilateral percutaneous balloon kyphoplasty through unilateral transverse process-extrapedicular approach for osteoporotic vertebral compression fracture of lumbar].

OBJECTIVE: To evaluate the feasibility and short-term effectiveness of bilateral percutaneous balloon kyphoplasty through unilateral transverse process-extrapedicular approach for osteoporotic vertebral compression fracture (OVCF) of lumbar. METHODS: A retrospective analysis was made on the clinical data of 93 patients with OVCF of lumbar who met the selection criteria between January 2018 and June 2019. According to the different surgical methods, they were divided into group A (44 cases, treated with bilateral percutaneous balloon kyphoplasty through unilateral transverse process-extrapedicular approach) and group B [49 cases, treated with percutaneous kyphoplasty (PKP) via bilateral transpedicle approach]. There was no significant difference in gender, age, body mass index, T value of bone mineral density, injury cause, fractured level, time from injury to operation, comorbidities, and preoperative Cobb angle of injured vertebra, visual analogue scale (VAS) score, and Oswestry disability index (ODI) between the two groups ( P>0.05). The operation time, intraoperative fluoroscopy times, bone cement injection amount, and incidence of bone cement leakage were recorded and compared between the two groups; Cobb angle of the injured vertebrae, VAS score, and ODI were measured before operation, at 2 days and 1 year after operation. The contralateral distribution ratio of bone cement was calculated according to the anteroposterior X-ray film at 2 days after operation. RESULTS: The operation time and the intraoperative fluoroscopy times in group A were significantly less than those in group B ( P<0.05). There was no bone cement adverse reactions, cardiac and cerebrovascular adverse events, and no complications such as puncture needles erroneously inserted into the spinal canal and nerve injuries occurred in the two groups. Bone cement leakage occurred in 6 cases and 8 cases in groups A and B, respectively, all of which were asymptomatic paravertebral or intervertebral leakage, and no intraspinal leakage occurred; the bone cement injection amount and incidence of bone cement leakage between the two groups showed no significant differences ( P>0.05). The contralateral distribution ratio of bone cement in group A was significantly lower than that in group B ( t=2.685, P=0.009). Patients in both groups were followed up 12-20 months, with an average of 15.3 months. The Cobb angle of the injured vertebrae, VAS score, and ODI in the two groups were significantly improved at 2 days after operation, however, the Cobb angle of the injured vertebra at 1 year after operation was significantly lost when compared with the 2 days after operation, the VAS score and ODI at 1 year after operation were significantly further improved when compared with the 2 days after operation, the differences were all significant ( P<0.05). There was no significant difference in the Cobb angle of the injured vertebrae, VAS score, and ODI between the two groups at each time point after operation ( P>0.05). CONCLUSION: Bilateral percutaneous balloon kyphoplasty through unilateral transverse process-extrapedicular approach is comparable to bilateral PKP in short-term effectiveness with regard to fracture reduction, reduction maintenance, pain relief, and functional improvement. It has great advantages in reducing operation time and radiation exposure, although it is inferior in bone cement distribution.

Diosgenin inhibits Wnt/ß-catenin pathway to regulate the proliferation and differentiation of MG-63 cells.

Dioscorea opposita Thunb has the effect of anti-osteoporosis, but whether its active ingredient diosgenin (DIO) has an anti-osteoporosis effect is unknown. The purpose of this study is to investigate the effect of DIO on the proliferation and differentiation of MG-63 cells. MG-63 cells were treated with different concentrations of DIO (0.001, 0.01, 0.1 and 1 µM) or 20 mM Wnt/ß-catenin signaling agonist-LiCl, and then their cell cycle and viability were analyzed by flow cytometry and 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT), respectively. To investigate osteoblast differentiation, alizarin red staining and ultraviolet spectrophotometer were used to determine the number of calcified nodules and the activity of alkaline phosphatase (ALP), respectively. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and western blotting were used to detect the expressions of proliferation-related, osteogenic-related and Wnt/ß-catenin signal pathway-related factors. After the cells were treated with low-concentration (0.001 or 0.01 µM) DIO, cell viability was significantly increased and the proportion of cells in S phase was increased. In addition, low-concentration DIO could significantly increase the expression of Ki67, proliferating cell nuclear antigen (PCNA), osteopontin (OPN), and osteocalcin (BGP), promote osteoblast differentiation, and suppress the expression of ß-catenin, Runx2 and cyclinD1. However, high concentrations of DIO showed the opposite effect. Low-concentration DIO obviously reversed the effect of LiCl on decreasing the number of calcified nodules and inhibiting the expression of OPN and BGP in cells. Low-concentration DIO might promote the proliferation and differentiation of MG-63 cell by inhibiting the Wnt/ß-catenin signal pathway.

Reduce the fractured central endplate in thoracolumbar fractures using percutaneous pedicle screws and instrumentational maneuvers: Technical strategy and radiological outcomes.

INTRODUCTION: Traumatic thoracolumbar burst fracture is a common condition without a clear consensus on the best treatment approach. Percutaneous pedicle screw fixation (PPSF) techniques are widely used in practice, while its ability to correct fracture deformity is relatively weak, especially for the central area of the endplate. In this study, we reported a novel technique to reduce the fractured central endplate in thoracolumbar burst fractures. METHODS: The new reduction technique uses six percutaneous pedicle screws for the fractured vertebra and its adjacent vertebrae. Pedicle screws implanted in the two adjacent vertebrae were parallel to the superior vertebral endplate, as routinely required. Two monoaxial pedicle screws implanted in the fractured vertebra were placed toward the anteroinferior portion of the fractured vertebral body. After routine instrumentation and ligamentotaxis reduction, the bolt heads of the four screws implanted in the adjacent vertebrae were first tightened, and then the bolt heads of the screws implanted in the fractured vertebra were gradually tighten to elevate the collapsed endplate. A fundamental principle of this technique is to implant the pedicle screw in the fractured vertebra towards the anteroinferior portion of the vertebra in such a way that the angle between the pedicle screw and the rod is oblique on lateral fluoroscopy. As such, when the bolt heads were tightened, the pedicle screws can be swung up to reduce the endplate fragments. RESULTS: The novel technique was performed in 24 patients with neurologically intact thoracolumbar AO type A3 fractures. The middle vertebral height ratio was significantly improved from 69.7%±7.6% after routine reduction to 85.1%±4.5% postoperatively (p<0.01). No complication was noticed for this new reduction technique. At 6-month follow-up, no significant correction loss of the middle and posterior vertebral height ratios, Cobb angle, and vertebral wedge angle was observed, while 5.8% of correction loss was observed for the anterior vertebral height ratio. CONCLUSION: The described reduction technique is simple, safe, and effective in reducing the collapsed central endplate in thoracolumbar burst fractures. Such a practical reduction strategy does not need additional medical costs.

[Short-term effectiveness of polyaxial locking plate for fixation of femoral neck fracture in middle-aged and elderly patients].

Objective: To evaluate the feasibility and short-term effectiveness of polyaxial locking plate for fixation of femoral neck fracture in the middle-aged and elderly patients. Methods: A retrospective analysis was made on the clinical data of 13 patients with femoral neck fracture undergoing fixation with polyaxial locking plates between September 2013 and June 2015 (group A) and 13 patients with femoral neck fracture undergoing fixation with three cannulated screws in the same period (group B). There was no significant difference in gender, age, side, cause of injury, Garden type, type of fracture position, type of Pauwels angle, Singh index, time between injury and operation, and preoperative complications between 2 groups ( P>0.05). The femoral neck shortening at 1 year postoperatively, and fracture nonunion, femoral head necrosis, and Harris hip score at last follow-up were compared between 2 groups. Results: The follow-up time was (19.23±3.98) months in group A and (18.00±3.61) months in group B, showing no significant difference between 2 groups ( t=2.063, P=0.417). No femoral head necrosis occurred in group A, but head necrosis occurred in 1 case of group B, and hemiarthroplasty was performed. There was no significant difference in the rate of femoral head necrosis between 2 groups ( χ2=0.000, P=1.000). Bone union was obtained in the other patients of 2 groups. The Harris hip score of group A (85.23±2.95) was significantly higher than that of group B (81.92±3.64) at last follow-up ( t=2.064, P=0.018). No infection or internal fixation failure occurred in 2 groups. One case had pain at the outer thigh at 1 month after operation in group A, but pain relief was achieved at 3 months after operation. At 1 year after operation, no femoral neck shortening occurred in group A, but degree I, II, and III femoral neck shortening was observed in 3, 2, and 8 cases of group B, respectively, showing significant difference between 2 groups ( Z=-4.714, P=0.000). Conclusion: Although fixation with polyaxial locking plate for femoral neck fracture in the middle-aged and elderly patients has similar femoral head necrosis rate to fixation with cannulated screws, it has advantages in preventing neck shortening and improving hip joint function after operation.

[ESTABLISHMENT AND TESTING OF RATING SCALE OF RAT ROTATOR CUFF FUNCTION].

OBJECTIVE: To provides an objective tool to evaluate rotator cuff function in rats. METHODS: Sixty adult male Sprague Dawley rats, weighing (281.21 ± 20.12) g, were involved in this experiment. Botulinum toxin A (6 U/kg) was injected into the infraspinatus of 12 rats in Botox group. Infraspinatus tendons of 12 rats in tear group were cut by microinvasive method. Infraspinatus tendons of 12 rats in sham-operation group were exposed but not cut. No any treatment was performed on the 12 rats in normal control group. One shoulder joint of each rat was selected randomly as treatment side. After 7 days, cadence, rate of stand phase, support pressure, swing speed, stand speed, and stride length of rats in those 4 groups were measured. Treatment side and contralateral side ratio of each gait parameter was caculated. If parameters of Botox group and tear group both showed significant differences compared with those of normal control group and sham-operation group, the gait parameter was brought into rating scale as an item. Each item was assigned from 1 point to 5 points according to gait parameter. The chronic rotator cuff injury model was established in 12 rats of verification group and rating scale was used to evaluate rotator cuff function each week for 8 weeks after surgery. RESULTS: All gait parameters of tear group were significantly less than those of Botox group (P < 0.05), and Botox group was significantly less than sham-operation group and normal control group (P < 0.05), but no significant difference was found between sham-operation group and normal control group (P > 0.05). All gait parameters were brought into rating scale as items. All items were rated from 1 point to 5 points, so the total score was 30 points and the lowest score was 6 points. Thirty points meant normal function of infraspinatus (rotator cuff function was normal), and 6 points meant complete loss of infraspinatus function (rotator cuff function was severely damaged). Rotator cuff functional scores of rats in verification group were 27.00 ± 1.86, 23.75 ± 2.83, 21.33 ± 1.92, 18.17± 2.37, 13.17 ± 1.64, 11.67 ± 2.50, 8.17 ± 1.27, 6.50 ± 0.67 from the 1st week to the 8th week respectively. CONCLUSION: The rating scale of rat rotator cuff function may reflect the severity of rotator cuff injury and the functional status of rotator cuff to some extent in rats.