ObjectiveTo review the literature on the research status of vascularization of tissue engineered peripheral nerve so as to provide the theoretical basis for the vascularization of tissue engineered peripheral nerve.MethodsThe literature related to the vascularization of peripheral nerve tissue engineering in recent years was reviewed and summarized according to the five aspects of promoting vascularization: local microenvironment and blood supply characteristics of peripheral nerve regeneration, scaffold material modification, seed cells, autologous vascular bundle implantation, and pro-vascular factors.ResultsTissue engineered peripheral nerve has brought a new hope for the repair of peripheral nerve injury, but the repair effect of large nerve defects is not good, which is mainly related to the degree of vascularization of the nerve grafts. So it is particularly important to promote the early vascularization of tissue engineered peripheral nerve. Previous studies have mainly focused on the four aspects of scaffold material modification, seed cells, autologous vascular bundle implantation, and angiogenesis related factors. Recent studies show that the combination of the above two or more factors in the tissue engineered peripheral nerves can better promote the vascularization of tissue engineered peripheral nerves.ConclusionPromoting early vascularization of tissue engineered peripheral nerves can provide timely nutritional support for seed cells on the scaffold, promote axon growth and nerve regeneration, and facilitate the repair of large peripheral nerve defects in clinical practice.
ObjectiveTo summarize the progress of research related to the surgical treatment of recurrent patellar dislocation by peripatellar osteotomy in clinical practice, in order to provide reference for clinical treatment. MethodsThe recent literature on peripatellar osteotomy for recurrent patellar dislocation at home and abroad was reviewed, and the bony structural abnormalities, imaging diagnosis, and treatment status were summarized. ResultsAbnormalities in the bony anatomy of the lower limb and poor alignment lead to patellofemoral joint instability through the quadriceps pulling force line and play an important role in the pathogenesis of recurrent patellar dislocation. Identifying the source of the deformity and intervening with peripatellar osteotomy to restore the biomechanical structure of the patellofemoral joint can reduce the risk of soft tissue surgical failure, delay joint degeneration, and achieve the target of treatment. ConclusionIn the clinical diagnosis and treatment of recurrent patellar dislocation, the factors causing patellofemoral joint instability should be comprehensively evaluated to guide the selection of surgery and personalized treatment.
Objective To summarize the latest research progress of bone cement type femoral head replacement in the treatment of unstable intertrochanteric fractures in elderly patients. Methods The literature on the application of bone cement type femoral head replacement for unstable intertrochanteric fractures in elderly patients both domestically and internationally was reviewed, and the findings in aspects of selection of prosthesis types, proximal femoral reconstruction methods, postoperative complications, and rehabilitation were summarized and analyzed. Results The bone cement type femoral head replacement has shown significant effectiveness in the treatment of unstable intertrochanteric fractures in elderly patients. The surgery provides immediate stability, allowing patients to quickly bear weight and regain walking function, thereby reducing the incidences of postoperative complications and mortality. However, due to the generally poor physical condition and low surgical tolerance of elderly patients, the risk of postoperative complications significantly increases, which has a significant impact on patients’ postoperative recovery. Common complications include deep vein thrombosis, bone cement implantation syndrome, joint dislocation, prosthesis loosening, and periprosthetic fractures. Therefore, despite the apparent short-term effectiveness of the surgery, it is crucial to emphasize the prevention and management of postoperative complications to improve the long-term prognosis of elderly patients. Conclusion For unstable intertrochanteric fractures in elderly patients, when choosing bone cement type femoral head replacement, it is necessary to strictly adhere to surgical indications, reduce the occurrence of complications, and improve the patients’ quality of life through refined preoperative evaluation, intraoperative operation, and effective postoperative management.
Objective To investigate the incidence of Modic changes of lumbar endplate and its cl inical significances. Methods The imaging data of 562 patients (2 810 lumbar intervertebral discs) with lumbar degenerative disease undergoingposterior operation from June 2006 to June 2009 were retrospectively reviewed. There were 297 males and 265 femalesaged 26-77 years old (average 49 years old). The course of disease was 2 months to 40 years (median 10.4 years). Imaging examinations excluded the tuberculosis, cancer, infection, trauma, etc. The association of Modic changes with low back pain (LBP) and patients’ weight was analyzed according to the incidence and types of Modic changes as well as the distribution of gender, age and disc level through imaging data of MRI. Results Modic changes were observed in 106 patients (18.9%) of 113 intervertebral discs, including 40 (13.5%) males and 66 (24.9%) females. The difference between male proportion and female proportion had a significant difference (P lt; 0.05). Modic changes was distributed from age 26 to 77 years old (average 49 years old). Among all the patients, 33 cases (5.9%) were type I, 66 cases (11.7%) were type II, and 7 cases (1.2%) were type III. According to the segment, the lesions involved L5, S1 disc for 58 discs (51.3%), L4, 5 for 35 (31.0%), L3, 4 for 11 (9.7%), L2, 3 for 6 (5.3%), and L1, 2 for 3 (2.7%). The incidence of Modic change was 15.5% (41/264) in the normal body weight group, 16.3% (34/208) in the over-weight group, and 34.4% (31/90) in the obesity group. There was a significant association between obesity and the Modic change (P lt; 0.05). Preoperatively, there were 59 patients (55.7%) with LBP in the Modic group, including 27 cases of type I Modic change, 27 cases of type II Modic change, and 5 cases of type III Modic change. Postoperatively, the LBP of 40 patients (67.8%) were rel ieved, including 24 cases of type I Modic change, 14 cases of type II Modic change, and 2 cases of type III Modic change. In non-Modic change group, there were 126 patients (27.6%) with LBP preoperatively, and 96 patients (76.2%) eased the symptoms postoperatively. There was significant difference between two groups on incidence rate (P lt; 0.05),but no significant difference on the remission rate of LBP (P gt; 0.05). Conclusion The most common Modic change is typeII and the most frequently involved level is the L5, S1. Modic changes are more common in female than in male and mainly happen to the obesity group. The incidence of LBP is higher in the patients with Modic change.
ObjectiveTo investigate the short-term effectiveness of free radial head reconstruction of coronoid process, artificial radial head replacement, and ulna olecranon internal fixation in the treatment of the complex terrible triad of the elbow.MethodsRetrospective analysis was made on the clinical data of 12 patients with complex terrible triad of the elbow treated with free radial head reconstruction of coronoid process, artificial radial head replacement, and ulna olecranon internal fixation between April 2011 and April 2018. There were 8 males and 4 females with an average age of 44.5 years (range, 26-62 years). The causes of injury included 5 cases of traffic accident, 7 cases of falling from hight. The Regan-Morrey classification of ulnar coronoid process fractures was type Ⅲ; Mason classification of radial head fractures was type Ⅲ in 7 cases and type Ⅳ in 5 cases. The time from injury to operation was 5-14 days, with an average of 6.0 days. The operation time, intraoperative blood loss, and complications were recorded. After operation, X-ray film of elbow joint was reexamined, fracture healing condition was observed, and fracture healing time was recorded. The flexion, extension, and rotation of the elbow joints on the healthy and affected sides were recorded and measured. The elbow function was evaluated according to Mayo elbow function score.ResultsThe operation time was 90-140 minutes (mean, 110 minutes); the intraoperative blood loss was 100-300 mL (mean, 150 mL). None of the patients had vascular injury during the operation. One patient developed numbness in the ulnar nerve innervation area and recovered completely after symptomatic treatment for 1 week. All the 12 patients were followed up 12-22 months, with an average of 16 months. At last follow-up, the fracture healed completely, 1 patient developed ectopic ossification of elbow joint, and 2 patients developed traumatic arthritis of elbow joint. No internal fixation-related complications occurred. There was no significant difference in the range of motion of elbow flexion, extension, pronation, and supination between the affected and healthy sides (P>0.05). The median Mayo elbow function score was 96, and the interquartile range was (94, 97), and the excellent and good rate was 91.7%.ConclusionFor patients with complex terrible triad of the elbow with ulna coronoid process fractures of Regan-Morrey type Ⅲ and radial head fractures of Mason type Ⅲ, Ⅳ combined with ulna olecranon fractures, the free radial head reconstruction, artificial radial head replacement, and ulna olecranon internal fixation, through active rehabilitation function exercise after operation, can achieve more satisfactory short-term effectiveness.
Objective To explore the biomechanical stabil ity of dynamic sleeve three-wing screw for treatment of femoral neck fracture and to provide theoretical basis for choosing dynamic sleeve three-wing screw in cl inical appl ication. Methods Nine human cadaveric femurs were selected and divided randomly into 3 groups (n=3), excluding deformities, fractures, and other lesions. The central neck of the specimens were sawn with hand saw respectively at Pauwels angles of 30, 50, and 70°. All cut ends were fixed with dynamic sleeve three-wing screw. Instron-8874 servohydraul ic mechanical testing machine was used to fixed the specimens which simulated uni ped standing, at the rate of 10 mm/minute and l inear load 0-1 200 N at 11 key points. The strain values of princi pal pressure side and princi pal tension side under different loads were measured. Results There was a peak at 6th point in the 1 200 N load. The strain values at Pauwels angles of 30, 50, and 70° were (—1 657 ± 171), (—1 879 ± 146), and (—2 147 ± 136) με; showing significant differences (P lt; 0.01). The strain values of princi pal pressure side and princi pal tension side of the femoral neck became higher with the increasing Pauwels angle under the same load, showing significant differences (P lt; 0.01). The strain values became higher with the increasing load under the same Pauwels angle (P lt; 0.01). Conclusion Dynamic sleeve three-wing screw has good biomechanical stabil ity for treatment of femoral neck fracture. It explains theoretically that the fracture is more unstable with the increasing Pauwels angle．
Objective To investigate the differences in biomechanical properties between fresh and chemically extracted acellular peri pheral nerve. Methods Thirty-six sciatic nerves were harvested from 18 adult male Wistar rats of 3 months old and randomly assigned into 3 groups (n=12 per group): normal control group (group A), the nerve segments received no treatment; Sondell method group (group B), the nerve segments were chemically extracted with the detergents of Triton X-100 and sodium deoxycholate; and improved method group (group C), chemically extracted acellular treatment of nerve was done with the detergents of Triton X-200, Sulfobetaine-10 (SB-10), and SB-16. After the acellularization, the structural changes of nerves in each group were observed by HE staining and field emission scanning electron microscope,then the biomechanical properties of nerves were tested using mechanical apparatus (Endura TEC ELF 3200). Results HE staining and field emission scanning electron microscope showed that the effect of acellularization of group C was similar to that of group B, but the effects of demyel ination and integrity of nerve fiber tube of group C were better than those of group B; the structure of broken nerves was more chaotic than before biomechanical test. The biomechanical test showed that the ultimate load, ultimate stress, ultimate strain, mechanical work to fracture in group A were the largest, the next was group C, the least was group B; the tenacity and elastic modulus in group C were the largest, the next was group B, the least was group A; but the differences were not significant (P gt; 0.05). Conclusion Compared with Sondell method, the nerve treated by improved method is more appropriate for use in vivo.
Objective To review the progress of the mechanisms of Wnt/β-catenin and nuclear factor-kappa B (NF-кB) pathways in the process of the intervertebral disc degeneration. Methods The related literature about the mechanisms of Wnt/β-catenin and NF-кB pathways in the process of the intervertebral disc degeneration was reviewed, analyzed, and summarized. Results Wnt/β-catenin and NF-кB pathways are both activated in the process of the intervertebral disc degeneration, and exist interaction. However, the specific mechanisms and interactive mediums of Wnt/β-catenin and NF-кB pathways in the process of the intervertebral disc degeneration are still unclear. Conclusion The mechanisms of Wnt/β-catenin and NF-кB pathways in the process of the intervertebral disc degeneration have to be studied deeply.
Objective To compare the biomechanical characteristics of the less invasive stabilization system (LISS) and the dynamic condylar screw (DCS) in the fixation of subtrochanteric fractures of the femur so as to provide theoretical basis for choosing internal fixator in clinical application. Methods Twelve cadaveric human femurs (35-50 years old) were selected with similar proximal femur, excluding deformities, fractures, and other lesions. The twelve femur specimens were randomly divided into 2 groups, 6 specimens per group. An 1 cm gap of osteotomy model was made in the proximal femur up to 1 cm below the lesser trochanter to simulate a comminuted subtrochanteric fracture of femur, and the distal end was embedded with denture acrylic and liquid for denture acrylic. Fracture was fixed by LISS in group A, and was fixed by DCS in group B. The specimens were fixed on Instron-8874 servo-hydraulic mechanical testing machine in a single-leg standing position, and the axial compression test and dynamic fatigue test were carried out to compare the compressive strength and the strain distribution at both sides of the fracture line. Results Axial compression test: the strain values of the 2 strain gauges in group A were significantly smaller than those in group B (P lt; 0.01); the vertical down displacement of the femoral head in group A was significantly smaller than that in group B (P lt; 0.01) under the same load; when the load was 600 N, the axial rigidity of group A was (209.06 ± 18.63) N/mm, which was significantly higher than that of group B [(65.79 ± 7.26) N/mm] (t=3.787, P=0.004). Dynamic fatigue test: the vertical down displacement of the femoral head in group A was significantly smaller than that in group B in the same cyclic loading cycle (P lt; 0.01); when the vertical down displacement of the femoral head was 0.5 mm, the force and the cyclic loading cycles in group A were significantly larger than those in group B (P lt; 0.01). Conclusion LISS, which has good mechanical stability, can meet the requirements for subtrochanteric fracture of femur fixation in biomechanics and anatomical structures. It can be proven that the LISS internal fixator is firmer than the DCS internal fixator by biomechanical comparison.
Trabecular microstructure is an important factor in determining bone strength and physiological function. Normal X-ray and computed tomography (CT) cannot accurately reflect the microstructure of trabecular bone. High-resolution peripheral quantitative computed tomography (HR-pQCT) is a new imaging technique in recent years. It can qualitatively and quantitatively measure the three-dimensional microstructure and volume bone mineral density of trabecular bone in vivo. It has high precision and relative low dose of radiation. This new imaging tool is helpful for us to understand the trabecular microstructure more deeply. The finite element analysis of HR-pQCT data can be used to predict the bone strength accurately. We can assess the risk of osteoporosis and fracture with three-dimensional reconstructed images and trabecular microstructure parameters. In this review, we summarize the technical flow, data parameters and clinical application of HR-pQCT in order to provide some reference for the popularization and extensive application of HR-pQCT.