The aim of this study was to evaluate the effect of the Topping-off technique in preventing the aggravation of degeneration caused by adjacent segment fusion. Clinical parameters of patients who underwent L5-S1 posterior lumbar interbody fusion + interspinous process at L4-L5 (PLIF + ISP) with the Wallis system (Topping-off group) were compared retrospectively with those of patients who underwent solely PLIF. Pre- and post-operative x-ray measurements, visual analogue scale (VAS) scores, and Japanese Orthopaedic Association (JOA) scores were assessed in all subjects. Normal L1-S1 lumbosacral finite element models were established in accordance with the two types of surgery in our study, respectively. Virtual loading was added to assess the motility, disc pressure, and facet joint stress of L4-L5. There were 22 and 23 valid cases included in the Topping-off and PLIF groups. No degeneration was observed in either group. Both VAS and JOA scores improved significantly post-operatively (P < 0.01). The intervertebral angle and lumbar lordosis of L4-L5 were both significantly increased (t = −2.89 and −2.68, P < 0.05 in the Topping-off group and t = −2.25 and −2.15, P < 0.05 in the PLIF group). In the Topping-off group, x-ray in dynamic position showed no significant difference in the angulation or distance of the anterior movement of the L4-L5 segment. The angle of hyper-extension and distance of the posterior movement of L4 were significantly decreased. In the PLIF group, both hyper-flexion and hyper-extension and posterior movement were increased significantly. In finite element analysis, displacement of the L4 vertebral body, pressure of the annulus fibrosus and nucleus pulposus, and stress of the bilateral facet joint were less in the Topping-off group under loads of anterior flexion and posterior extension. Facet joint stress on the left side of the L4-L5 segment was also less in the Topping-off group under left flexion loads. Short-term efficacy and safety between Topping-off and PLIF were similar, whilst the Topping-off technique could restrict the hyper-extension movement of adjacent segments, prevent back and forth movement of proximal vertebrae, and decrease loads of intervertebral disc and facet joints.

Objectives: The aim of this study was to investigate the incidence of vertebral refractures following percutaneous kyphoplasty (PKP) and to explore risk factors for augmented vertebral refractures, thereby assisting spinal surgeons in clinical practice. Methods: We analyzed the records of 495 patients with single-segment osteoporotic vertebral compression fractures (OVCFs) who were treated with single-entry PKP at our institution from March 2016 to August 2022. Univariate analysis, binary logistic regression, and ROC curve analysis were performed to determine potential risk factors, independent risk factors, and discrimination ability. Results: A total of 168 patients were included in the study, with a median follow-up duration of 7.00 months. In total, 143 patients did not experience vertebral refracture after surgery, while 25 patients did, including 22 augmented vertebral fractures and 3 adjacent vertebral compression refractures. The correction rate of the Cobb angle (p < 0.001; OR = 1.070) and postoperative anti-osteoporosis treatment (p = 0.002; OR = 0.021) were independently associated with augmented vertebral refracture. The ROC curves showed that these variables demonstrated satisfactory predictive values for augmented vertebral refracture. Conclusions: A high degree of restoration of the Cobb angle was the factor contributing to vertebral refracture after PKP. Conversely, postoperative anti-osteoporosis treatment was observed to be a protective factor against subsequent vertebral refracture.

With the increasing demand for total knee arthroplasty (TKA) surgery, more attention has been paid to the accurate measurement of pressure and adjustment of knee prosthesis. The tightness between artificial meniscus and articular head and the thickness of artificial meniscus will directly affect the matching between knee joint and human body. At present, the installation and adjustment of knee joint during operation largely depends on the personal experience of doctors. In this work, a flexible pressure sensing device with bendable and distortable sensor arrays for force detection in knee arthroplasty is fabricated and characterized to provide quantitative data guidance and reference for knee arthroplasty. The internal pressure of prosthesis knee joint can be effectively detected through real-time obtaining for output voltages of sensor array. The densely distributed measuring points feedback abundant pressure distribution information. The pressure device shows good repeatability, consistency and small hysteresis in large detection range and stability in dynamic response which indicates promising potential in applications of knee arthroplasty.

Surface electromyogram (sEMG)-based gesture recognition has emerged as a promising avenue for developing intelligent prostheses for upper limb amputees. However, the temporal variations in sEMG have rendered recognition models less efficient than anticipated. By using cross-session calibration and increasing the amount of training data, it is possible to reduce these variations. The impact of varying the amount of calibration and training data on gesture recognition performance for amputees is still unknown. To assess these effects, we present four datasets for the evaluation of calibration data and examine the impact of the amount of training data on benchmark performance. Two amputees who had undergone amputations years prior were recruited, and seven sessions of data were collected for analysis from each of them. Ninapro DB6, a publicly available database containing data from ten healthy subjects across ten sessions, was also included in this study. The experimental results show that the calibration data improved the average accuracy by 3.03%, 6.16%, and 9.73% for the two subjects and Ninapro DB6, respectively, compared to the baseline results. Moreover, it was discovered that increasing the number of training sessions was more effective in improving accuracy than increasing the number of trials. Three potential strategies are proposed in light of these findings to enhance cross-session models further. We consider these findings to be of the utmost importance for the commercialization of intelligent prostheses, as they demonstrate the criticality of gathering calibration and cross-session training data, while also offering effective strategies to maximize the utilization of the entire dataset.

BACKGROUND Bone cement displacement (BCD), which has received increasing attention from scholars, is a serious complication following vertebroplasty in patients with osteoporotic vertebral fractures (OVFs), and percutaneous kyphoplasty (PKP) might promote its occurrence. However, few studies have systematically explored the risk factors of BCD after PKP. This research aimed to study the risk factors for BCD following PKP. MATERIAL AND METHODS The clinical data of patients with OVFs treated with PKP from June 2016 to August 2022 in our department were retrospectively reviewed. Patients were categorized into the bone cement displacement group and the bone cement non-displacement group. Data on the subjects and their radiologic images were gathered for univariate analysis and binary logistic regression analysis. The receiver operating characteristic (ROC) curve and confusion matrix were utilized to assess the discrimination ability. RESULTS We included 181 patients, of which 12 had BCD after PKP. Binary logistic regression analysis revealed that independent risk factors associated with BCD after PKP were: high BMI, high restoration rate of the Cobb angle, high distance between the bone cement and the vertebral endplates, and presence of bone cement leakage. The ROC curve and confusion matrix indicates that logistic regression exhibited a strong predictive value for BCD. CONCLUSIONS Patients with a high BMI, a high restoration rate of the Cobb angle, a high distance between the bone cement and the vertebral endplates, and bone cement leakage have an increased risk of BCD after PKP.

Dynamic interspinous stabilization devices generally provide satisfactory results, but can result in recurrent lumbar disc herniation, spinous process fracture, or bone resorption of the spinous process. The purpose of this study was to investigate if the Wallis dynamic stabilization device is associated with bone resorption. Patients who underwent single-segment posterior lumbar decompression and implantation of a Wallis dynamic interspinous stabilization device at the L4/5 level between January 1, 2009 and October 1, 2011 were included. Bone resorption rate, Oswestry Disability Index (ODI), Japanese Orthopedic Association (JOA) score, and visual analogue scale (VAS) pain score were measured. Patient baseline and 1-year follow-up data were collected and analyzed. The bone resorption rate of the L4 and L5 spinous processes was calculated. Twenty four males and 20 females with a mean age of 42.7 ± 14.7 years were included. Twenty nine patients had significant bone resorption (bone resorption rate > 20%) and 15 had no bone resorption (bone resorption rate ≤ 20%) at 1 year after surgery. Lumbar lordosis ≥ 50° was associated with a lower bone resorption than lumbar lordosis < 50° and increasing BMI was associated with increased bone resorption. There were no significant differences between the bone resorption and no bone resorption groups in the improvement rate of VAS pain score, ODI, and JOA score at 1 year after surgery. Significant bone resorption occurs within 1 year after implantation of the Wallis device in more than 50% of patients. However, it does not affect short-term functional results.