[Objective]To investigate the influence of pressure on the proliferation of rabbit bone marrow stromal cells(MSCs) and explain the relationship of the hip prosthesis submerge and loosening with continuous pressure after revision of total hip replacement.[Method]A unit of MSCs pressure model was set up to load different pressures on MSCs cultured in vitro.[Result]MSCs showed more proliferation capacity under discontinuous pressure.MTT assay was used to determine the cell proliferation of primarily cultured MSCs under discontinuous pressure.The MSCs OD value of pressured groups was much smaller than the control group at different times.Various magnitudes and durations of the discontinuous pressure could significantly suppress MSCs proliferation with the magnitude-dependent.[Conclusion]At the early period after revision of total hip replacement,patients should lie and exercise on the bed until 6 weeks.Otherwise,the weight-bearing pressure may restrain MSCs proliferation which is harmful to union and may cause prosthesis submerge and loose.

Objective To compare the clinical efficacy and radiologic changes between constrained and non-constrained titanium plate in anterior cervical corpectomy and fusion (ACCF) in elderly cervical spondylosis patients.Methods A total of 58 elderly cervical spondylosis patients who underwent ACCF were divided into group 1 (patients treated with constrained titanium plates,n =30) and group 2 (patients treated with non-constrained titanium plates,n=28).The Japanese Orthopedic Association (JOA) score,fusion rate,the loss of segmental height and cervical lordosis were recorded.The clinical efficacy and imaging features were compared between the two groups.Results The improvement rate of JOA score had no significant differences between group 1 and group 2 [(77.7±18.6)％ vs.(75.8±23.2)％,t=0.340,P＞0.05].At 3 months after operation,the fusion rate was higher in group 2 than in group 1 (89.3％ vs.63.3％,x2 =5.327,P＜0.05).At 3,6 and 12 months after operation,there were no significant differences in the loss of segmental cervical height and lordosis between group 1 and group 2 [(2.42±3.05)mm vs.(0.98±2.86)mm,(3.95±3.65)mm vs.(2.34±2.97)mm,(3.60±4.33)mm vs.(2.40±2.96)mm,(1.64±2.33)° vs.(0.66 ± ±2.14)°,(2.13∧±±3.79)° vs.(0.70±2.99)°,(2.39±4.26)° vs.(0.86±3.25)°,respectively,all P ＞0.05].Conclusions The clinical efficacy is similar in ACCF with the two types of titanium plates.The non-constrained titanium plate can increase the fusion rate in early time,but may aggravate the loss of segmental cervical height and lordosis,which should be used with caution in elderly osteoporosis patients.

OBJECTIVE: To study the correlation between quantity of the connexin43 express and ischemia time in rabbit. METHODS: Left coronary arteries were ligated to create early myocardial ischemia during distinct time, HBFP staining was used in the ischemia spot and SP method was used to show the expression of connexin43 and the ischemia are were measured by the computer image analysis. RESULTS: Negative correlation was observed between the connexin43 quantity and the ischemia time. The significant was difference. CONCLUSION With ischemia time raised, expression of connexin43 was descented.
Animals ; Connexin 43/metabolism* ; Female ; Immunohistochemistry ; Male ; Myocardial Ischemia/pathology* ; Myocardium/pathology* ; Rabbits ; Staining and Labeling/methods* ; Time Factors

Objective:To propose a monosegment thoracic and lumbar fracture dislocation (mTLFD) classification, and to evaluate its reliability and clinical application.Methods:All of 298 cases of thoracic and lumbar fracture dislocation who received surgical management in our hospital from January 2014 to December 2019 were retrospectively analyzed. 123 cases were included in the study according to inclusion and exclusion criteria. mTLFD classification was proposed based on the imaging characteristics: type I (intervertebral disc injury mainly) and type II (vertebral burst fracture mainly). The type II was classified based on distribution of injury segment: type IIa (T 11 and above) and Ttype IIb (below T 11). Six spinal surgeons (3 residents, 3 associate chief physicians) were selected to classify the 123 cases according to preoperative imaging data, and to perform reliability test of each type. The repeatability and reliability of the classification were evaluated by ICC index. Different management strategies were performedf or each type: type I was managed with posterior decompression interbody fusion and internal fixation; type IIa underwent posterior decompression and fixation, subtotal vertebral resection and fusion was performed if bony compromise was still present through intra-operative exploration. Type IIb underwent posterior decompression, posterolateral fusion and internal fixation on the first stage, while anterior subtotal vertebral resection and reconstruction was performed on the second stage if the bony compromise was still present based on post-operative CT examination. The American Spinal Injury Association (ASIA) grading of all patients was recorded, and the visual analogue scale (VAS), Oswetry disability Iindex (ODI) and local Cobb angle of each type was compared between pre-operation and final follow-up. Results:The average follow-up time of all patients was 10.4±1.8 months. The average repeatability and reliability ICC index of mTLFD of 3 residents and 3 deputy chief physicians were 0.926 and 0.964, respectively, and 0.746 and 0.907, respectively. The reliability ICC index of type I, type IIa and type IIb was 0.918, 0.947 and 0.962, respectively, and the repeatability ICC index was 0.930, 0.940 and 0.966, respectively. The neurological function recovery was obtained in 56 patients. The preoperative VAS of type I, type IIa and type IIb were 8.5±1.0, 8.4±1.0 and 8.3±0.9, and 2.0±1.1, 1.8±1.0 and 1.8±0.9 at the final follow-up (all P<0.001). The ODI of type I, type IIa and type IIb were 97.0%±2.1%, 97.1%±1.9% and 97.3%±2.1% before surgery, and 29.5%±6.8%, 27.0%±6.0% and 29.0%±6.7% at the final follow-up (all P<0.001). The local Cobb angles of type I, type IIa and type IIb were 20.9°±7.1°, 29.0°±9.1° and 26.4°±6.9° before surgery, and 12.5°±5.4°, 18.0°±9.1° and 13.1°±5.1° at the final follow-up (all P<0.001). Conclusion:The mTLFD classification proposed in this study has strong repeatability and reliability, and management strategy of each type have achieved satisfactory clinical efficacy, indicating that the classification has certain significance for management of thoracic and lumbar spine fracture dislocation.