Objective In order to meet the quantitative measurement of soft tissues balance required in the TKR,a new soft tissues balance navigation system have been developed and used experimentally in adjusting the soft tissue release of medial collateral ligament(MCL)and quantitative measurement of the force change in extension gap or flexion gap after various kinds of MCL release during TKA.Methods Six precise load sensors have been embedded in the front measure device,which is inserted into the cutting gaps of the 5 knee joints of cadavers to measure the force of MCL before or after various types of releases.The device has the function of changing distance between its upper and lower plates by the mechanical structure for the adjustment of different bone cutting space.The reading of the sensors representing the force are displayed in three or two-dimensional manner in real-time with accuracy of better than 0.098 N per bit.Results The preliminary test shows that the measurement system can accomplish the force measurement and the distance adjustment in the knee joint,and its application for measuring the force of medial collateral ligament shows a quantitative force change in MCL in different knee position and different way of release.Release of the posterior portion of MCL mainly produces laxity of MCL at full extension with 33.61% reduction rate of tensional force in value.Complete medial collateral ligament release causes laxity of MCL both at full extension and 90? flexion with reduction rate of 44.96% or 41.30% respectively.Conclusion The soft tissues balance measurement device are capable of clinical use for navigation of soft tissue balance in TKA and performing knee dynamics research.It has been proved quantitatively that the posterior portion of MCL plays an important role in stability for extended knee while the anterior portion of MCL mainly stabilizes the knee in flexion.

Objective To compare the difference of static balance ability in different aged people, with the maximum angle of center of mass (COM) and center of pressure (COP). Methods 37 healthy people without cardiovascular and cerebrovascular diseases including 15 young people (18~40 years old), 10 middle age people (41~65 years old) and 12 old people (>65 years old) participated in this study. The maximum angle of COM-COP and the corresponding envelope areas were recorded in 4 standing posture: natural standing, close eyes standing, single leg standing and single leg standing with eyes closed. Results There was no significant difference in the maximum angle of COM-COP among 3 groups in 3 states (nature standing, close eyes standing, single leg standing with eyes closed) (P>0.05), but there was significant difference in the state of single leg standing (P<0.05) between the young and the old, and the middle-aged and the old. Conclusion The maximum angle of COM-COP in the state of single leg standing can sensitively detect the deterioration of stability of older people. It may be a new index of static balance in clinic.

Objective To analyze the practical experiences of design and its clinical application of custom-made tumor prostheses of knee. Methods A retrospective study of 41 cases of distal femur or proximal tibia tumors treated surgically from June 1999 to October 2002, was carried out. In the study, there were 29 males and 12 females aging from 11 to 69 years with an average of 35.0 years. The location of tumors were at distal femur in 23 cases and 9 cases at proximal tibia, of which 15 were osteosarcoma, 13 giant cell tumor, 3 chondrosarcoma, 5 solitary metastatic bone tumor, and 1 each of fibrosarcoma, malignant fibrohistocytoma, Ewings sarcoma, small round cell sarcoma and syndesmofibroma. The custom-made semi-constrained knee prosthesis with femoral or tibial component was implanted after extra-capsular resection of the tumor bone segment. A special femoral component with elongated construction was used in an 11-year old case for further femur lengthening. Resection of femoral artery involved by tumor and reparation by great saphenous vein was performed in one case. Results The operations of the 41 cases were all smoothly performed. 33 cases were followed up from 8 to 37 months with an average of 20.2 months. The daily life ability was recovered in 3 months after the operation. Among them, no loosening or failure of the prostheses was found, and local recurrence was found in 2 cases and distant metastasis in 3 cases. The design of knee prosthesis could provide some proper internal/external rotation and adduction/abduction movements accompanying with the flexion and extension of the knee joint without affecting the stability of the joint. For the case of proximal tibia tumor, a special design and surgical technique was developed to provide the reconstruction of patellar ligament insertion with rather good results; and the recovery of knee extension and stability were satisfied. Conclusion The custom-made semi-constrained tumor prosthesis of knee could be used as an effective method for the limb-savage management either the distal femur or proximal tibia tumor cases.

Objective To explore a new approach giving soft tissue balance in valgus knee during total knee arthroplasty. Methods A modified lateral parapatellar approach with function of spontaneous release of lateral retinaculum was designed and used for valgus knee during total knee arthroplasty, by which knee joint was exposed with incision between the superficial and deep retinaculum layer together with lateral eversion of fat pad. After release of the constrained structures of the knee at lateral side such as lateral retinaculum, iliotibial band,lateral posterior capsule or lateral collateral ligament the prosthesis was implanted; the superficial and deep retinaculum layers were sutured back in proper tension position in order to maintain a normal patella femoral relationship and then the deep layer was closed. Within 2 weeks after operation CPM was instituted and ambulation was allowed with crutches 2 weeks after operation. Results All of 11 cases so treated healed up without skin problem. The valgus deformities were mostly corrected with a rate of 85.3% from average 10.2 degrees valgus preoperatively to average 1.5 degrees varus postoperatively. Two months postoperation the average range of motion reached 105 degrees and the knees were stable in level walking. Nine of 11 cases were able to go up and down stairs. Conclusion Modified lateral parapatellar approach was suitable for total knee arthroplasty with severe valgus deformity. [

BACKGROUND:Hip segmentation based on CT image has been widely used in computer-assisted surgery planning, prosthesis design and finite element analysis. OBJECTIVE:To explore application effects of automatic segmentation method for hip joint based on Bayesian Decision Theory in computer-assisted hip surgery. METHODS:An accurate outer surface segmentation and extraction remain chal enging due to deformed shapes and extremely narrow inter-bone regions. In this paper, we present an automatic, fast and accurate approach for segmentation of femoral head and proximal acetabulum. The outline of the femur was segmented and extracted by contrast enhancement, thresholding algorithm and region growth algorithm. The boundaries of the bone regions are further refined based on Bayes decision rule. RESULTS AND CONCLUSION:Automatic segmentation method for hip joint based on Bayesian Decision Theory is an accurate segmentation technique for femoral head and proximal acetabulum and it can be applied in computer-assisted hip surgery and prosthesis design.

Objective To explore the expression, as well as the proportion of subsets of the natural killer (NK) T cells in peripheral blood of patients with esophageal carcinoma before and after surgery, and provide ideas and experimental basis for immune treatment through tests. Methods Using CD3, CD56, CD4 and CD8 antibody to study the NKT cells and its subsets. Peripheral NKT cell subsets in 59 patients with esophageal carcinoma were analysed by flow cytometer. Results With the ratio of CD+3 CD+56 CD+8/CD+3 CD+56 CD+4 gradually increased, the proportion of phase Ⅲ- Ⅳ patients with esophageal carcinoma is gradually decreased between the groups. One-way ANOVA analysis showed that there were differences between the groups (P ＜0.05). The ratio of CD+3 CD+56 CD+8/CD+3 CD+56 CD+4 was in Non-linear related to CD+3 CD+56 CD+4NKT cells; CD+3 CD+56 CD+8; NKT cells were positively correlated with CD-3 CD+56 NK cells and negatively correlated with CD+3 T cells.Conclusion The ratio of CD+3 CD+56 CD+8/CD+3 CD+56 CD+4 may relate to tumor burden, and is helpful to determine the extent of disease in patients with esophageal carcinoma and prognosis.

Objective To investigate the effect of gastric bypass on plasma glucose and glucagonlike peptide-1 (GLP-1) during oral glucose tolerance test (OGTT) in non-obese type 2 diabetes mellitus (T2DM) patients suffering from gastric ulcer necessitating a gastrectomy.Methods Thirty-two T2DM patients undergoing gastric bypass (GBP) for gastric ulcer were enrolled in this study.All patients underwent a 3-h OGTT with 75 g glucose (in a total volume of 300 ml) preoperatively and 1 week,1 month,3 months and 6 months after operation.Plasma glucose (PG) and GLP-1 concentrations were measured before (baseline) and then 30,60,120,and 180 minutes after OGTT.Areas under curves (AUC) were calculated by trapezoidal integration.The turnover of the diabetes conditions six months after the surgery were also measured.Results FPG level was (9.5±1.0) mmol/L before surgery,and significantly decreased to (7.4±1.0) mmol/L,one week,(6.5±1.2) mmol/L,one month,(8.0±1.6) mmol/L three months and (5.8±1.0) mmol/L,six months respectively after GBP(P ＜0.01).Peak level and AUC of PG during OGTT significantly decreased at aforementioned four time points after sugery (P ＜ 0.01).Oral glucosestimulated peak levels of GLP-1 was (20±3) pmol/L before GBP,and markedly increased to (83±15)pmol/L,(86±20) pmol/L,(87±22) pmol/L and (92±20) pmol/L respectively after GBP(P＜0.01).Stimulated AUC levels of GLP-1 significantly increased from (2457±395) pmol· min/L to (6499±1227)pmol·min/L,to (7275±1475) pmol·min/L,to (7307±1575) pmol·min/L and to (7974±1594)pmol· min/L during the study respectively(P ＜0.01).BMI levels were similar before and after GBP(P＞0.05).Two patients experienced complications(infection of incision and intractable hiccup).T2DM control rate was 78% when assessed at a time point of six months later.Conclusion Gastric bypass is effective in terms of glucose control and improving gucose tolerance in non-obese T2DM,and the hypoglycemic effect may be contributed to more GLP-1 secretion after GBP,but not to weight loss.

Objective To compare the efficacy and safety between local injection of triamcinolone and oral methylprednisolone in preventing esophageal stricture formation after endoscopic submucosal dissection (ESD) in patients with early esophageal cancer.Methods From January 2014 to January 2016,67 patients with early esophageal cancer were enrolled,all of them received ESD and were divided into triamcinolone injection group (22 cases),oral methylprednisolone group (22 cases) and control group (23 cases).Patients of triamcinolone group received injection of triamcinolone at injured mucosal under endoscope immediately after ESD.Patients of oral methylprednisolone group took methylprednisolone 30 mg per day since the third day after ESD,and then dosage reduced 5 mg every other week until drug withdrawal.Patients of control group only received ESD.After operation,gastroendoscopy examination was repeated to evaluate the extent of esophageal stricture.Patients with esophageal stricture were treated with an additional endoscopic balloon dilatation (EBD).The rate of esophageal stricture and the frequency of EBD treatment of the three groups were compared.Chi-square test,Wilcoxon rank sum test and Kruskal-Wallis rank sum test were used for statistical analysis.Results The rates of esophageal stricture of triamcinolone injection group,oral methylprednisolone group and control group were 18.2％ (4/22),13.6％0 (3/22) and 73.9％ (17/23),respectively,and the difference was statistically significant (x2 =22.20,P＜0.01).There was no significant difference in the rates of esophageal stricture between triamcinolone injection group and oral methylprednisolone group (x2 =0.17,P=0.50),but the rate of esophageal stricture in triamcinolone injection group was lower than control group,and the difference was statistically significant (x2 =14.03,P＜0.01);the rate of esophageal stricture in oral rnethylprednisolone group was lower than control group,and the difference was also statistically significant (x2 =16.55,P＜0.01).The median frequency of EBD treatment of triamcinolone injection group,oral methylprednisolone group and control group were 2.1 (range 0 to 4.0),1.6 (range 0 to 3.0) and 6.0 (range 0 to 13.0) times,respectively,and the difference was statistically significant (H =17.80,P ＜ 0.01).There was nosignificant difference in the frequency of EBD treatment between triamcinolone injection group and oralmethylprednisolone group (Z=1.21,P=0.23);but the frequency of EBD treatment in triamcinolone injection group was less than control group,and the difference was statistically significant (Z=4.96,P＜ 0.01);the frequency of EBD treatment in oral methylprednisolone group was less than control group,and the difference was also statistically significant (Z=4.32,P＜0.01).There was no severe adverse effect in the three groups.Conclusions Local injections of triamcinolone and oral methylprednisolone both reduced the rate of esophageal stricture after ESD,and decreased frequency of EBD treatment in patients with esophageal stricture.The two regimens showed equal efficacy and good safety.

Objective To establish a finite element model of rotator cuff which can be used to simulate the rotator cuff injury and to evaluate the biomechanical effects of rotator cuff surgery.Methods The Dicom CT images of the right shoulder of a Chinese healthy volunteer were used to establish models of the scapula,humerus and clavicle.The rotator cuff structures were separated and modeled based on the MRI images and anatomical knowledge.After the rotator cuff model was introduced into the finite element analysis software Abaqus 6.12,the anatomical positions were simulated when the shoulder was at 30° internal rotation,30° external rotation,30° abduction,30° adduction,30° flexion and 30° extension.Results When the shoulder was in 30° flexion,the average stress was 52.2 kPa on the supraspinatus,223.0 kPa on the inffaspinatus and the teres minor,and 90.4 kPa on the subscapularis.When the shoulder was in 30° extension,the average stress was 105.0 kPa on the supraspinatus,78.2 kPa on the infraspinatus and the teres minor,and 55.7 kPa on the subscapularis,indicating that the muscle and tendon of the supraspinatus was subjected to greater stress and the humerus and the scapula produced less stress compared with the shoulder in 30° flexion.Conclusion Since our finite element model of the rotator cuff can simulate common activities of the shoulder joint and obtain stress values of the corresponding rotator cuff muscles,it can be used in simulation of rotator cuff injury and its surgery.

Objective To analyse the dysfunction of immunity and clinical significance in patients with cardiac cancer.Methods The level of CD4+ CD25hi CD127low Treg cells were detected by flow cytometry (FCM),and serum IL-10 and TGF-β1 levels were determined by enzyme linked immunosorbent assay (ELISA) kit in 56 patients with cardiac cancer.15 healthy volunteers were tested as normal controls.The clinical data of each patient were collected and analyzed. Results There was a significantly higher percentage of CD4+ CD25hi CD127low Treg cells in patients with cardiac cancer (5.73±1.56)% than that (4.45±1.06)% of healthy volunteers (P<0.01).The IL-10 and TGF-β1 levels in the serum of patients with cardiac cancer were also significantly higher than that of healthy volunteers (P<0.05).There was a positive correlation between levels of IL-10.TGF-β1 and the levels of CD4+ CD25hi CD127low Treg cells.The number of CD4+ CD25hi CD127low regulatory T cells in the peripheral blood of cardiac cancer patients were significantly correlated with clinical stages and metastasis lymph node.Conclusion The CD4+ CD25hi CD127low Treg cells in the peripheral blood of cardiac cancer patients is significantly increased in comparison with that in healthy volunteers,and was also correlated with different stages.The abnormal levels of CD4+ CD25hi CD127low Treg cells may be related to tumor progression in patients with cardiac cancer.