Pedicle screw fixation is biomechanically most reliable for reconstruction of the cervical spine, which can ef?fectively restore cervical sagittal profiles, provide rigid fixation and higher fusion rate. Because of the large individual differ?ences in cervical pedicle, vertebral artery and nerve root, preoperative evaluation should be individualized. Cervical pedicle screw techniques include freehand technique and the computer-assisted navigation technology developed recently. Although complications associated with cervical pedicle screw fixation cannot be completely obviated, they can be minimized by com?bination of sufficient preoperative imaging studies of the pedicles and meticulous surgical techniques of screw placement. Cervical pedicle screw fixation techniques have been used in the treatment of various cervical disorders, with fewer complica?tions and good clinical efficacy, and a wide range of clinical applications.

Objective To investigate the effect of apoptosis with portal vein occlusion in various degrees or times and the following restoration portal vein flow on intestinal mucosal cells,to analyze its possible pathogenesis. Methods 40 healthy adults white Japanese rabbits were randomly divided into one controlled group and four experimental groups (according to portal vein half-clamping for 30 min, 45 min and portal vein full-clamping for 30 min, 45 min, divided into B1、C1、B2、C2 groups.).Each experimental group with portal vein occlusion on certain times then with restoration of portal vein flow for 2h. At choiced time rabbit guts were continuously cut to sections for HE、TUNEL staining and Bcl-2、Bax protein immunohistochemical staining,to observe the injury apoptosis in intestinal mucosa and the relationship between the expressions of Bcl-2 and Bax protein. Results Compared with control group A, down-regulation of Bcl-2 expression, up-regulation of Bax expression and the index of apoptotic cell increased were found in each experimental group. there exist significantly differences between each groups for Bcl-2 expression (P

[Objective]To explore the "acute angle" of femur,and evaluate the bone tunnel technique in posterior cruciate ligament reconstruction.[Method]Using the porcine flexor digitorum tendon as graft,the author reconstructed posterior cruciate ligament.The bone tunnel was established with the angle of 80?,90?and 100?comparison the tunnel and intercondylar fossa of femur side wall,and press sensitive film was set between the edge of tunnel and graft.The pressure between was used to represent abrasion.The bigger the pressure was,the larger the abrasion was.The difference of pressure between bone tunnel technique group and the control group was compared.[Result]The pressure of angle 100?was lowest(3.55?0.21 MPa).And the pressure of burnishing group(3.29?0.19 MPa)was lower than that of the control group(3.55?0.21 MPa).[Conclusion]The bone tunnel technique can reduce the femoral;"acute angle" of femur in posterior cruciate ligament reconstruction.

In order to study the role played by infection in the occurrence and mechanism of negative nitrogen balance of the skeletal muscles in the early stage of scalding,37% TBSA full thickness scalding was inflicted on the back and one hind leg of rats and the protein catabolic rate in the soleus muscle of both the scalded and healthy legs was determined and the effects of endotoxin on the catabolic rate were observed.It was found that the protein catabolic rate was markedly accelerated in the scalded soleus 3 days after iujusy;and showed no significant changes in the healthy one,in which the protein catabolic rate was near or similar to that of the normal control.After 2 mg/kg of endotoxin was administered intraperitoneally.the findings were as follows:(1)Endotoxin could also accelerate the protein catabolic rate in the skeletal muscles;(2)The protein catabolic rate in the scalded soleus was not further increased and no summation effect of scalding and endotoxin on protein catabolism occurred.

45.0?5.4)was higher than those who underwent omnidistance tourniquet technology.The incidence rate of hematoma and venous thrombus of lower extremity had no obvious difference.[Conclusion]The postoperative blood loss can be reduced and early postoperative clinical effect and affected limb function can be improved by halfway tourniquet technology for patients who underwent TKA.

Objective To observe the clinical effects of open kinetic chain and closed kinetic chain exercise in the early period of anterior cruciate ligament reconstruction rehabilitation,provide the theoretical and clinical experiences for the early rehabilitation of the anterior cruciate ligament reconstructed knee.Methods From February 2009 to June 2010,60 patients undergoing single-bundle anterior cruciate ligament reconstructions by using hamstring tendon allograft were enrolled in the study,and were divided into two groups:open kinetic chain group(30 cases,30 knees)and closed kinetic chain group(30 cases,30 knees).In accordance with the rehabilitation procedures for six months,no statistically significant differences were found between the two groups in Lysholm scores,International Knee Documentation Committee(IKDC)scores and one-leg hop test preoperative.The active and passive range of notion,Lysholm scores,IKDC scores,one-leg hop test and KT-1000 were evaluated three and six months after surgery.Results Three months after surgery,no significant differences were found in passive range of motion,Lysholm scores,IKDC scores,but significant differences were found in active range of motion,one-leg hop test and KT-1000,and the closed kinetic chain group was significantly better than the open kinetic chain group.Six months after surgery,no significant differences were found in active range of motion,passive range of motion,one-leg hop test,Lysholm scores,IKDC scores,but significant difference in KT-1000,and the closed kinetic chain group was significantly better than the open kinetic chain group.Conclusion Closed kinetic chain exercise is benefit for recovery of muscles strength,proprioception and protect the graft in the early rehabilitation period after anterior cruciate liganent reconstruction.

A rapid resolution liquid chromatography quadruple time-of-flight mass spectrometric ( RRLC-Q-TOF/MS) method combined with multivariate statistical analysis was applied to investigate the changes of endogenous metabolites in murine urine before and after ultraviolet B ( UVB ) irradiation for the purpose of discussing the physiological mechanism of acute injury caused by UVB radiation. A narrow-band UVB ( NB-UVB) (TL-01, peak value 312nm) was used to establish the acute light damage model. The urine samples were centrifuged before four times dilution treatment, subsequently the diluted urine samples were separated on a Supelco Ascentis Express C18 column using water (0. 1% formic acid) and acetonitrile as mobile phase by gradient elution. The differences metabolites with major contribution for grouping were found out based on the metabolic profiling analysis of principal component analysis ( PCA) and cluster analysis ( CA) , which could illustrate their possible mechanism of actions by means of relevant pathways. A prediction model was built to investigate the forecasting ability of the acute photo damage induced by UVB irradiation through the partial least square discriminant analysis ( PLS-DA ) . The results of multivariate statistical analysis showed that the blank control group was separated from UVB model group quite well, 11 endogenous metabolites were identified as the potential biomarkers through comparison with the database, tandem mass spectrum data and standard substance, which indicated the UVB radiation may affect the sphingolipid metabolism, nucleic acid metabolism, linoleic acid metabolism and amino acid metabolism pathways. These different metabolites could be helpful for diagnosing the light damage induced by UVB radiation

Objective To evaluate the effects of posterior segmental pedicle screw instrumentation and augmentation using calcium sulphate cement in treatment of Denis type B thoracolumbar burst fractures.Methods Forty patients with Denis type B thoracolumbar burst fracture treated between January 2011 and December 2012 were reviewed retrospectively.Twenty patients received posterior short-segment pedicle screw fixation in conjunction with screw placement at the level of fracture and calcium sulphate augmentation without posterolateral fusion (combined treatment group),but 20 patients underwent traditional short-segment pedicle screw fixation (conventional treatment group).Radiographs and CT scans evaluated local kyphotic angle on the spot of injury,anterior height of the injured vertebra,and canal encroachment before and after operation and at final follow-up.Meanwhile,visual analogue score (VAS),Oswestry disability index (ODI),and neurologic status based upon ASIA 2000 were assessed.Results Mean follow-up period was 15 months (range,12-24 months).Vertebral height restoration was equivalent of the two groups immediately after operation,but better result of kyphosis correction was found in treatment group than in control group (P ＜ 0.05).Anterior vertebral height and kyphotic angle significantly improved in treatment group compared to control group at final follow-up (P ＜ 0.05).Clinical and neurologic outcome evaluation were similar between the two groups.No implant failure occurred at follow-up.Conclusion For Denis type B thoracolumbar burst fractures,posterior segmental pedicle screw fixation augmented with calcium sulphate is effective for reducing correction loss and implant failure,compensating for the deficiencies of conventional fixation.

Objective To investigate the impact of graft position shift on anterior cruciate ligament reconstruction induced by femoral fixation of interference screw. Methods Nineteen fresh cadaveric knees were used and assigned to three groups. 1) Study of graft position shift: 5 knees were randomly selected, interference screws of 7 mm, 8 mm and 9 mm were used in autologous tendon fixation, then the graft position shift were measured. 2) Study of isometry: 7 knees were randomly divided into the isometric reconstruction group (D group). In the D group, Retrobutton, interference screw and interference screw in location-corrected bone tunnel were used respectively as fixation. The isometry of grafts was evaluated. 3) Study of tibia anterior translation: 7 knees were randomly divided into the anatomic reconstruction group (J group). In the J group,the tibia anterior translation was measured in four different conditions in the same joint: intact knee joint,knee joint without ACL, ACL anatomic reconstruction by interference screw fixation, and ACL anatomic reconstruction by interference screw fixation with corrected bone tunnel location. Results 1) With 7 mm, 8mm and 9 mm interference screw fixation, graft position shift were (2.36±0.11) mm, (2.72±0.06) mm and (3.00±0.06) mm respectively. 2) Graft length change: graft length change in Retrobutton group and corrected bone tunnel group were less than 3 mm, while graft length change in those fixed with interference screw were stretched in more than 3 mm. 3) Study of tibia anterior translation: there was no difference among the intact group, the anatomic group and the corrected group at 0° and 15°. However, the difference was found between the intact group and other groups at 30°、60° and 90° of flexion, as well as between these two reconstructed methods at 20° joint flexion (P＜0.05). Conclusion In both isometric and anatomic ACL reconstruction with interference screw, the graft is pushed tightly toward the femoral tunnel wall, which shifts the graft away from the desired position. In our study we find out that the corrected location of the femoral bone tunnel significantly improves the isometry of ACL reconstruction and anatomic reconstruction.

Objective To evaluate the clinical efficacy of treatment of severe thoracolumbar burst fractures by posterior short-segment instrumentation without spinal fusion and assess radiographic imaging and function recovery after surgery.Methods Thirty-eight patients with severe monosegmental thoracolumbar burst fractures treated between July 2011 and March 2013 were analyzed retrospectively.Operation procedures were posterior short-segment pedicle screw distraction reduction and fixation combined with screw insertion to the injured vertebrae and calcium sulphate augmentation.In addition,there was no need for posterolateral interbody fusion.X-ray and CT were performed before and after operation to evaluate local kyphotic angle,anterior fractured vertebral body height and canal encroachment.Visual analogue scale (VAS) and Oswestry disability index (ODI) were assessed before and after operation as well as in follow-up.Results All patients were followed up for average 14 months (range,3-20 months).Local kyphotic angle was (21.2 ±4.3)° before operation,(3.5 ± 1.8)°immediately after operation,and (4.8 ± 2.7) ° in final follow-up.Relative anterior vertebral height was (54.8 ± 14.6)％ before operation,(91.7 ± 8.0)％ after operation,and (87.2 ± 6.0)％ in final follow-up.Mean canal encroachment was (48.0 ± 4.5)％ preoperatively,(23.8 ± 7.8)％postoperatively,and (8.8 ± 4.6) ％ in final follow-up.In final follow-up,six patients with American Spinal Injury Association (ASIA) grade C on admission showed improvement to grade D (n =2) and grade E (n =4) ; 10 patients with ASIA grade E on admission showed improvement to grade E; 22 patients with grade E had no changes.ODI and VAS scored 15.5 ±8.8 and 2.3 ±0.8 in final follow-up with substantial improvement from those before operation (P ＜ 0.01).Complications from internal fixation were not found during follow-up.Conclusion Posterior short-segment fixation without fusion is one of the foremost effective methods for severe thoracolumbar burst fractures,for it can effectively restore the sagittal spinal alignment and the fractured vertebral body height.