Joint contracture is currently one of the very common diseases in rehabilitation medicine department.Once it occurs,it likely leads to such functional disturbances in the patients as restricted joint activities,decreased muscle strength around a joint and abnormal gait,seriously affecting the quality of life of the patients.Studies on its pathogenesis can help doctors better understand and treat the disease.In this paper,pathogenesis of the disease and progress in its therapy are summarized.

Oblique lateral interbody fusion (OLIF) is a new technique in spine surgery,through oblique lateral retroperitoneal approach,it can establish a work corridor direct access to the intervertebral space between the psoas muscles and the abdominal vessels sheath.Through the retroperitoneal work corridor,OLIF can complete intervertebral fusion of anterior and middle column,restore the height of intervertebral space and foramen,and make the spinal canal or nerve root indirect-decompression.OLIF is applicable to degenerative lumbar spine diseases,spinal tuberculosis,tumor,kyphosis,postoperative renovation,trauma,etc.OLIF conforms to the current trend of minimally invasive spinal surgery,which has many advantages like less surgical trauma,less surgical bleeding loss,shorter hospital stay,faster recovery,less damage to the abdominal organs,no stimulation of the spinal nerve,and less damage to the psoas and lumbosacral plexus.Although OLIF has theoretically great advantages,the postoperative hip flexion weakness,the groin and thigh area pain and numbness,contralateral nerve injury and other complications are often reported,notwithstanding the complications are considered to be related to long time psoas compression which results in the psoas and lumbosacral plexus injury,large fusion device implantation which leads to contralateral nerve root injury and so on.The primary cause is that the surgeon blindly pursues new technology with lack of knowledge about the new technology,as well as indications and contraindications,the anatomy of the working area,the details of the surgical operation,etc,causing complications associated with technology or access.Further understanding of the OLIF operation process,including mastering the local anatomy and grasping the surgical indications and contraindications is essential for successful application of OLIF technology to treat various lumbar disorders.

The unilateral biportal endoscopic technique is defined as posterior unilateral of two small incision with established percutaneous observation channel and endoscopic observation channel in monitoring field. The operation tools were placed within the channel for each operation inside and outside vertebral canal. The characteristics of dual channel intervention make this technology different from coaxial endoscopic technology. This technique has a clear vision for flexible and convenient operation with the advantages of relatively simple surgical instrument requirements. In recent years, the use of unilateral dual channel endoscopic surgery in treating spinal diseases was gradually increasing, especially in the removal of nucleus including lumbar intervertebral disc protrusion and lumbar spinal stenosis disease decompression, and in endoscopic space-occupying lesions such as vertebral fusion and spinal canal between inside and outside. It was also applied in cervical and thoracic diseases with good clinical effects. Its advantages include less surgical trauma and faster recovery process. In addition, it has a large surgical field of vision under the microscope for easy identification of structures and surgery and with relatively gentle learning curve. Thus, it is conducive to beginners' mastery. However, complications such as nerve injury and postoperative lower limb numbness are still frequently reported. Some factors have to be considered, including insufficient understanding of the new technology, the local anatomy of the dual-channel endoscope, the operation of the spinal canal under the microscope. The successful application of the technique in treating various lumbar diseases needs understanding the operation process of the technique and local anatomy under the microscope.

Objective:To develop a unilateral biportal endoscopic technique and investigate the clinical efficacy of unilateral biportal endoscopic technique in the treatment of lumbar disc herniation and lumbar spinal stenosis.Methods:Between July 2018 and June 2019, 60 patients with lumbar disc herniation or spinal stenosis were treated by unilateral biportal endoscopic technique. According to the inclusion and exclusion criteria, 51 patients were included in the study. There were 25 cases of prolapsed lumbar disc herniation, 26 cases of degenerative lumbar spinal stenosis, all of which were treated with posterior lumbar decompression by unilateral biportal endoscopic laminectomy, and contralateral stealth decompression by unilateral approach was performed on the patients with bilateral stenosis. Endoscopic interbody fusion and percutaneous pedicle screw fixation were performed in 5 patients with instability. Operation time, length of incision, hospital stay and complications were recorded. Visual analogue scale (VAS) for low back pain and leg pain, Oswestry dysfunction index (ODI) and the modified Macnab scale were used to evaluate the clinical efficacy.Results:All operations were completed successfully, and no cases were transferred to open surgery. The operative time was 70.29±19.55 min (44-151 min), while the length of incision was 1.79±0.34 cm (1.4-3.0 cm). Postoperative CT suggested complete decompression with intact contralateral structure. All patients got out of bed 1-3 d after surgery, and the postoperative hospital stay was 3.49±2.76 d (1-14 d). The postoperative follow-up time was 13.59±2.80 months (10-21 months). Forty-six patients returned to work or normal activities within 3 weeks and 5 patients with interbody fusion returned to normal activities within 4 weeks. According to the modified Macnab criteria, the final outcome was excellent in 43 cases, good in 6 cases, and fair in 2 cases. There were 3 cases of dural sac tear during operation and 2 cases of transient numbness of lower limbs after surgery and they all recovered after conservative treatment. The VAS score of low back pain of 26 patients with lumbar spinal stenosis was reduced from 6.69±1.44 before surgery to 3.27±1.43 at postoperative 1 month, 2.69±1.57 at postoperative 3 months, 2.31±1.16 at postoperative 6 months and 2.23±1.28 at the last follow-up, respectively, and the difference was statistically significant ( F=128.534, P<0.005). The VAS scoreof leg pain was reduced from 6.77±1.34 before surgery to 3.27±1.37 at postoperative 1 month, 2.88±1.48 at postoperative 3 months, 2.85±1.52 at postoperative 6 months and 2.54±1.53 at the last follow-up, and the difference was statistically significant ( F=146.951, P<0.005). The ODI score was reduced from 64.18%±8.23% before surgery to 37.53%±4.45% at postoperative 1 month, 27.51%±3.83% at postoperative 3 months, 19.91%±5.27% at postoperative 6 months and 6.84%±2.74% at the last follow-up, and the difference was statistically significant ( F=783.966, P<0.005). The VAS score of low back pain of 25 patients with lumbar disc herniation was reduced from 5.60±1.38 before surgery to 3.04±1.54 at postoperative 1 month, 2.84±1.75 at postoperative 3 months, 3.12±1.86 at postoperative 6 months and 3.44±1.69 at the last follow-up, respectively, and the difference was statistically significant ( F=22.357, P<0.005). The VAS scoreof leg pain was reduced from 5.48±1.45 before surgery to 2.88±1.64 at postoperative 1 month, 2.52±1.83 at postoperative 3 months, 2.76±1.83 at postoperative 6 months and 3.00±1.92 at the last follow-up, and the difference was statistically significant ( F=29.445, P<0.005). The ODI score was reduced from 53.59%±6.87% before surgery to 32.46%±3.78% at postoperative 1 month, 23.39%±2.78% at postoperative 3 months, 16.49%±3.49% at postoperative 6 months and 7.23%±3.15% at the last follow-up, and the difference was statistically significant ( F=790.985, P<0.005). Conclusion:Unilateral biportal endoscopic technique has the advantages of clear and wide field of vision, large operating space, relatively simple surgical instrument need and convenient and flexible operation procedure. It has excellent clinical effects in the treatment of lumbar disc herniation and lumbar spinal stenosis.

Objective To establish a model of knee joint extension contracture in New Zealand white rab-bits, and to lay the experimental foundation for further studies on the pathogenesis and treatment of joint contractures. Methods Thirty male New Zealand white rabbits with mature bones were randomly divided into 6 groups. The left knee joints of the immobilization groups ( 5 groups of 5 rats each) were fixed in extension for 1, 2, 4, 6 or 8 weeks. There was also a control group. At the end of each period the plaster was demolished and the level of transforming growth factor-β1 ( TGF-β1) in joint cavities, the degree of total contracture, myogenic contracture, arthrogenic con-tracture, and the thickness of the posterior joint capsules were measured. The significance of the differences between the immobilized groups and the control group was compared using one-way analysis. Results The level of TGF-β1 in the joint fluid differed significantly among the 6 groups. The differences in the degree of total contracture among the control group, one-week, two-week and four-week groups were also significant. The average degree of the myogenic contracture in the one-week group was significantly different from the other 5 groups' averages. The average myogenic contracture was also of significantly different between the two-week group and the control group. The degree of arthro-genic contracture was significantly different among the groups except for between the 6-week and 8-week groups. The average joint capsule thickness was significantly different among all of the groups except for between the control group and the one-week group. Conclusion This technique for modeling knee extending contracture using New Zealand white rabbits is simple and practical. It provides a better animal model for studying the mechanism of knee joint con-tracture and related treatment strategies and can be used for further exploration of the occurrence and recovery of knee contractures.

Objective:To investigate the effect of application of problem-based learning (PBL) combined with evidence-based medicine (EBM) in clinical practice teaching of an orthopedic department.Methods:A total of 48 interns who entered Department of Orthopedics, The Second Hospital of Anhui Medical University, Hefei, China from June 2017 to June 2018 were randomly divided into experimental group (the PBL combined with EBM concept teaching group, n = 24) and control group (the traditional teaching group, n = 24). In the experimental group, teachers selected typical cases, designed questions with certain flexibility and complexity, and organized the students to consult the literature, discuss in groups, and report and summarize around the practical problems. In the control group, traditional indoctrination teaching was adopted according to the clinical experience of the teachers. The teaching effect was assessed by a questionnaire survey, a theoretical examination, and a clinical skill examination. The results were analyzed by t-test and Chi-square test using SPSS 16.0 software. Results:The questionnaire survey showed that compared with the control group, the experimental group gave a significantly better evaluation of the teaching methods they received in terms of improving their theoretical knowledge comprehension ability, comprehensive analysis ability, team collaboration awareness, document retrieval and language expression ability, stimulating their learning motivation, and enhancing their scientific thinking and innovation ability ( P < 0.05). Furthermore, compared with the control group, the experimental group had significantly higher mean scores for both the theoretical test (92.42±2.55 vs. 86.17±3.36, P < 0.05) and the clinical skill test (85.79±3.15 vs. 78.88±3.41, P < 0.05). Conclusion:The application of PBL teaching in orthopedic practice, with the concept of EBM throughout the teaching process, has obtained a good effect. It can improve the clinical teaching quality in orthopedics, improve the comprehensive quality of clinical medical students, inspire their active learning enthusiasm, and cultivate their creative thinking, problem construction, comprehensive analysis, literature retrieval, and communication ability.