Objective To investigate the feasibility and clinical effects of the pair ringer technology for bony avulsion of the posterior cruciate ligament under arthroscopy. Methods From January 2005 to July 2009, 23 patients were treated with the pair ringer technology for bony avulsion of the posterior cruciate ligament by arthroscopy. There were 15 male and 8 female, with an average of 39.3 years (ranging from 28 to 52 years). There were 4 cases of type Ⅱ, 14 type Ⅲ, and 5 type Ⅳ according to Meyer-Mckeever classification. The outcome measures were X-ray and MRI testing, Lysholm and Tegner knee function score. Results All the operations were finished in an hour. There were no complications as nerve injury or infection occurred in the study. The patients were followed-up for an average of 16.5 months (12-23 months). The Lysholm score rose from 50.3±6.1 preoperatively to 89.7±8.3 at the six months postoperatively (t=18.34, P=0.0007). The Tegner score rose from 1.7±0.5 preoperatively to 5.7±1.3 at the six months postoperatively (t=13.77,P=0.0008). All of the patients recover a functionally stable knee and have considerably improved knee function compared with their preoperative status. Conclusion The pair ringer technology under arthroscopy is a liable method for bony avulsion of the posterior cruciate ligament. This minimally invasive technology leads to rigid fixation, early rehabilitation.

Objective To investigate effects of radiofrequency vaporization in arthroscopic treatment of knee disorders.Methods Arthroscopic surgery was conducted in 126 consecutive cases of various knee disorders by using the Arthrocare 2000 System,includng 72 cases of meniscus injury,20 cases of synovitis,15 cases of osteoarthritis,8 cases of patella subluxation,6 cases of synovial syndrome,and 5 cases of anterior cruciate ligament rupture.Results All the patients were followed postoperatively.Knee function evaluation with the Neer Scores showed excellent outcomes in 82 cases,good in 35 cases,and fair in 9 cases,the rate of excellent-or-good outcomes being 92.9%.Conclusions Application of radiofrequency vaporization under arthroscopy for knee joint disorders has advantages of simple and accurate performance,effective hemostasis,minimal invasion,and quick recovery of joint functions.

Objective To studythe effect of CD+4CD+25 regulatory T(Tr)cells on dendric cells(DC)in peripheral blood and deciduas from unexplained recurrent spontaneous abortion(URSA)patients.Methods Four URSA patients(abortion group)and 4 normal early pregnant women(control group)were enrolled in this study.Tr cells and DC in the peripheral blood and deciduas were isolated using Ficoll density gradient centrifugation and magnetic cell sorting(MACS).DC were cultured alone(DC alone)or in combination with Tr cells(DC+Tr)for 6 days,during which the release of interferon(IFN)-γandinterleukin(IL)-10 in the medium was subsequently measured by enzyme linked immunoadsorbent assay (ELISA).Results(1) Peripheral blood:there was no significant difference in IFN-γlevel between DCalone(23.2±0.7)ng/L and DC+Tr(22.5±3.0)ng/L in abortion group(P>0.05).The similar level of IL-10 was observed between DC alone(37±7)ng/L and DC+Tr(35±4)ng/L in abortion group(P>0.05).IL-10 level,but not IFN-γ,was significantly hisber in DC alone(54±20)ns/L than that in DC+ Tr(36±9)ng/L in control group(P<0.01).(2)Deciduas:there was no significant difference in IFN-γlevel between DC alone(23.4±2.6)ng/L and DC+Tr(24.4±2.5)ng/L in abortion group(P>0.05).Moreover,Similar IL-10 level was found between DC alone(28±7)ng/L and DC+Tr(25±5)ng/L in abortion group(P>0.05).IFN-γlevel in CD alone(30.7±4.6)ng/L was significantly higher than that in DC+Tr(22.6±3.8)ng/L in control group(P<0.01);whereas IL-10 level was much lower in DC alone (27±6)ng/L than that in DC+Tr(31±9)ng/L in control group(P<0.05).Conclusion The decreasing of immunosuppressive funetion of Tr eell of URSA patients affect its regulation on DC.resulting in imbalance of Th1/Th2 and abnormality of maternal-fetal jmmuno-tolerence in URSA.

Objective To investigate the feasibility and clinical effects of suture anchors technique for acute distal avulsion fracture of patella. Methods From January 2007 to July 2009, 33 patients(18males and 15 females, ranging from 28 to 72 years, with an average of 49.3 years) were treated with the suture anchors technique. The average time from injury to surgery was 3.5 days(2 to 7 d). Injury reason: traffic accident in 12 cases, injured in daily life in 11 cases, sports injury 9 cases, no clear trauma history in one case. The Bostman evaluation system, follow-up X-ray, and knee mobility were used to analyze the clinical effects of suture anchors technique. Results All patients obtained the follow-up and the average time was 16.5 months(12 to 23 months ). One patient suffered foreign body reaction, and his wound healing was good after operation. The remaining patient wound healing was good. No complications were found in all patients,such as popliteal fossa artery, tibial nerves or peroneal nerve complication. Bostman patella fracture functional score 27.3±2.3 points at the sixth months follow up, 28 cases were rated as excellent, 5 cases were good, and the excellent and good rate was 100%. Six months later, X-ray showed bone healing, knee activity recovered well. The Range of Motion was extension for -2.5°±2.1° and flexion for 122°±5.3°. Conclusion Suture anchors fixation in treatment of acute distal avulsion fracture of patella has a good efficacy, safety and reliability advantages, and without the second operation. This technique provides an alternative in lower pole patella fracture.

Objective To evaluate the accuracy of thoracic pedicle screw placement using the "funnel technique" and investigate its consistency in experimental study and clinical application.Methods The clinical data of three human cadavers and 11 patients with the installation of at least one thoracic pedicle screw at T1 -T12 from August 2006 to July 2008 were retrospectively analyzed. One junior spine surgeon lack of experience were responsible for placing these screws with the "funnel technique".The accuracy of screw placement and the complications related to the use of thoracic pedicle screws were analyzed by assessing postoperative CT scans. Results The mean follow-up time was 23.1 months,which showed no vascular or visceral complications, or iatrogenic neurological injury. The rate of unintended cortex perforations was 14% (10/72) in cadavers and 15% (8/55) in patients, respectively.The critical perforation occurred in two screws (3%) in cadavers and one screw (2%) in patients. There was no statistical difference between the percentage of cortex perforations in cadavers and patients. Of all the 11 patients, screw violation occurred laterally in six ( 11% ), medially in one ( 2% ) and superiorly in one (2%). No violations occurred inferiorly or anteriorly. For all patients, only one screw needed revision. The perforations made by the junior spine surgeon occurred in six screws in the first cadaver, three in the second cadaver and one in the third cadaver. Conclusions The "funnel technique" is a simple,safe, accurate and cost-effective technique for pedicle screw placement. The result of the experimental study is consistent with that of the clinical application. "funnel technique" is helpful for junior spine surgeons to master the technique of thoracic pedicle screw placement.

Objective To study the optimum combination of orientation parameter of total hip prosthesis and acetabular safe zone on condition that the range of motion for activities of daily living (ADL) is fulfilled.Methods A three-dimensional generic parametric and visually kinematic simulation module of THA was developed.Range of motion ( ROM ) of hip flexion ≥ 110°,internal-rotation ≥30° at 90° flexion,extension ≥30° and external rotation ≥40° were defined as the normal criteria for ADL.ROM of hip flexion ≥ 120°,internal-rotation ≥45° at 90° flexion,extension ≥30° and external rotation ≥40° were as the severe criteria.The ranges of changes in general ratios (GRs) of head-neck,femoral neck antevemion ( FNA ),operative inclination (OI) and anteversion (OA) of acetabulur components were 2.0-2.92,0°-30°,10°-60°,and 0°-70° respectively.Within the limits of the upper two activity criteria,the synchronous OA of acetabulur components was calculated with every 5°change in OI of the cup,and the collodiaphyseal angle ( CDD ) was set as 135°.The safe-zone of combination of acetabulur operative anteversion (OA) and inclination (OI) was defined as the area that fulfilled the two mentioned criteria of ROM without cup-neck impingement.All parameters were analyzed by using SAS 6.12 software.Results The safe zone of acetabdar angle rose with the increase of GRs of head-neck and the safe zone of severe criteria was smaller than that of normal criteria.When the CDD angle was 135°,the sum of average aeetabular OA and acetahular OI plus 0.816 times of the FNA equaled to 84.76° innormal criteria; and the sum of average acetabular OA and acetabular OI plus 0.873 times of the FNA equaled to 92.04° in severe criteria.Conclusions A high GR of head-neck greatly increases the size of safe-zone of acetabular angle.The higher demand of ROM of hip joint requires the smaller safe zone of acetabular angle,as can be corrected by increasing the GR of head-neck.The optimum combination between the sum of average acetabular OA and acetabular OI ( Y) plus FA (X)in the normal criteria and severe criteria can be estimated by using the following formulae:Y1 =-0.816X1 + 84.76 (R2 =0.993 ),Y2 =-0.873X2 + 92.04( R2 =0.999) respectively.

Objective To explore the spatial distribution of schistosomiasis cases and Oncomelania snails in the provinces of Jiangsu, Anhui and Jiangxi with the assistance of geographic information systems (GIS). Methods Epidemiological data of schistosomiasis in recent 20 years were collected, and the relevant GIS databases were established. The spatial autocorrelation analysis was carried out with ArcView 3\^x, S\|Plus, and Spatial Statistics software. Results Except for schistosomiasis cases in Jiangsu, the spatial distribution of schistosomiasis cases and Oncomelania snails in the three provinces were fitted to the spatial autocorrelation at a certain degree. Generally the autocorrelation coefficients (Moran′s I) in Oncomelania snails were higher than that in schistosomiasis cases. Conclusion Spatial autocorrelation analysis can be used to estimate the value of one variable in different spatial position, and it is a good way to find out the spatial cluster distribution in different stages.

Objective To explore the isometry of grafts in PCL(posterior cruciate ligament)double-bundle re-construction under femoral tunnel shifting condition.Method Knee specimens from ten fresh frozen cadavers were used.PCL were divided into anterolateral bundles(ALB)and posteromedial bundles(PMB)to the inser-tion footorint.The anterior,postedor,proximal,distal and central points of the two bundles'femoral attachment site were respectivelyanchored to the middle of the PCL's tibial attachment site by the trial wires.Changes in length of the intra-articular part of the wires were recorded while the knee was flexed from 0°to 120°.Result The length changes in every point were compared.All of the maximal length changes of ALB's proximal,pos-todor points and PMB's proximal points were not greater than 2mm.No significant difference between the length changes of ALB's proximal point and posterior(P=0.864>0.05)was found.Conclusions The femo-ral tunnel for the PCL double-bundle reconstruction should be located as follows:ALB should be at the middle point of upper edge of femoral attachment site(proximal point),while PIVIB at the middle point of femoral attachment site(proximal point).

ObjectiveTo study the anatomic characteristic of the attachment of medial patellofemoral ligament and its function in patellar stability. MethodsThirty adult cadaver knees were used for anatomic study, and the attachments of medial patellofemoral ligament were observed and measured. Results The femoral attachment of medial patellofemoral ligament was anchored to the bone between the medial femoral epicondyle and the adductor tubercle. The fibers here were thin and narrow, and became thick and wide to the anterior. The patellar attachment was in the superior two-thirds of the medial margin of the patella. The fiber here were the thickest and the widest. Conclusion The anatomic characteristic of the attachment of medial patellofemoral ligament was revealed, providing anatomical bases for surgery.

Objective To provide an anatomic evidence for the double-bundle posterior cruciate ligament (PCL) reconstruction, the sizes and locations of the attachments of the PCL to the tibia and the femur were measured. Methods We studied 30 cadaveric knees. PCLs were divided into anterolateral and posteromedial bundles to the insertion footprint, and those locations were measured and described. Results The distances from the center of the femoral insertions of the anterolateral and posteromedial bundles to the anterior margin of the medial femoral condyle were (8.52±1.81)mm and (11.63±1.81)mm. The vertical distances from the center of the femoral insertions of the double-bundle to the intercondylar roof were (4.67±0.55)mm and (10.32±1.23) mm. The vertical distances from the tibial insertion of the center of the double-bundle to the plane of the tibial articular surface were (8.43±1.21)mm and (14.52±2.31)mm. The distances from the medial margin of the articular cartilage of the tibial plateau to the center of the tibial insertions of double-bundle were (47.44±6.23)mm and (45.95±6.32)mm. The areas of the insertions of the anterolateral and posteromedial bundles on the femur were (107.12±15.25)mm~2 and (65.35±10.27)mm~2. The areas of the insertions of the double-bundle on the tibia were (50.07±11.33)mm~2and (51.08±10.22)mm~2. Conclusion The anatomic characteristic of the attachment of the anterolateral and posteromedial bundles was revealed, providing anatomical bases for surgery.