[Objective]To assess the functional outcome,influence factors and its management of lateral wedge high tibial osteotomy(HTO)in patients with symptomatic lateral thrust and varus malalignment.[Method]The results of 19 lateral closing wedge HTOs in patients with a symptomatic hyperextension-varus thrust were evaluated from 2000 to 2004.The average age of the patients at the time of surgery was 49 years(ranged,47~54 years).Radiographs were analyzed to compare changes in femorotibial angle,tibial slope,and the height of the fibular head pre-and postoperatively.Functional results were evaluated according to the scoring system of HSS.The varus stress test was used to evaluated the posterolateral knee injury.We used a 5-point visual analogue scale to assess change in knee stability.[Result]Patients were followed for an average of 21 months.Femorotibial axis alignment was 184.5?～197?preoperatively and 167?～176?postoperatively;Posterior tibial slope was 2?～17?preoperatively and-4?～13?postoperatively;The height of fibular head was 7.7～18.5 mm preoperatively and-3.5～10.7 mm postoperatively(P=0.00).All patients had an increase in their HSS score postoperatively.Sixteen patients had Grade 1 posterolateral injuries and 3 patients had Grade 2 injures preoperatively,9 patients had Grades 1 injures and 10 patients had Grade 2 injures(P

Objective To study the effect of the high molecular weight polyethylene on the periprosthetic tissue in diabetic model and investigate the effect of TNF-α in periprosthetic tissue.Methods Induction of experimental diabetes in rabbit with streptozotocin was performed successfully,every rabbit's lower limb was implanted a kirschner wire plug in femur by intereondylar notch.In experimental group,15 mg polyethylene particles,dispersed in 1.5 ml normal saline solution,were injected into one knee joint.The other knee joint was injected 1.5 ml normal saline solution ag control.This procedure was repeated for 2,4,6,8,10,and 12 weeks after the implantation.All animals were killed on the 2nd week after the last injection.Knee joint capsule tissues and periprosthetie tissues were examined by optical microscope.ELISA was used for determing the concentration of TNF-α.Results The results showed that kirschner wire were surrounded by multinueleated foreign-body giant cells and osteoclagt in the experimental group.Synovial membrane proliferation was obvious in the control group.There were no polyethylene particles and multinucleated foreign-body giant cells around plug in the marrpw.New bone wag found,kitschner wire was surrounded by suosteoblast,and normal synovial membrane was appeared.The concentration of TNF-α in experimental group was higher than that in control group.Conclusion Maximal ultra high molecular weight polyethylene and diabetic mellitus can restrain diabetic rabbit pefiprosthetic bone formation and increase the secretion of TNF-α.which may play an important role in the periprosthetic osteolysis.

Objective The purpose was to explore the preventive measures of patellar baja following high tibial osteotomy for osteoarthritis, and the correlation between alteration in the inclination of the proximal tibial articular surface and patellar baja was evaluated as well. Methods In the group, there were 41 cases (48 knees), which included 30 males and 11 females, aging from 45 to 56 years with the mean age of 52 years. The size of resected bone of the arthritic knee needed to achieve a normal angle was calculated, and an additional 3 to 5 degrees of overcorrection was added to achieve approximately 10 degrees of genu valgum. The Insall-Salvati ratio, the inclination of the proximal tibial articular surface, the tibial tubercle height and the anatomic axis of the affected limbs were measured on the preoperative, postoperative as well as the final follow-up radiographs respectively. Chi-square test and linear regression analysis were used to assess the influence of loss of proximal tibial articular inclination on the patellar height. In the statistical analysis, loss more than 5 degrees of proximal tibial articular inclination and lowering more than 10% of the patella following tibial osteotomy were assumed of clinical significance. Results Compared with the preoperative results, the postoperative inclination of the proximal tibial articular surface was decreased by a mean of 6.14 degrees; the postoperative Insall-Salvati ratio was decreased by a mean of 10.6%; the postoperative height of the tibial tubercle was decreased by a mean of 3.13 mm. 64.6% (31/48 knees) endured loss more than 5 degrees of posterior tibial inclination after high tibial osteotomy, whereas 56.2% (28/48 knees) showed a relative lowering of patellar height more than 10%, as measured by the Insall-Salvati ratio. The loss of the normal posterior tibial inclination was found to have a statistically significant correlation with the subsequent loss of the patellar height. Conclusion The loss of inclination of the proximal tibial articular surface is found to have a correlation with the loss of the patellar height. Clinically, the result suggests that preserving the inclination of the proximal tibial articular surface at the time of high tibial osteotomy could minimize the risk of patellar lowering after the high tibial osteotomy.

Objective To evaluate the possibility for the treatment of chondral defects on the femoral bearing surface with autologous osteochondral transplantation under arthroscopy. Methods There were 17 patients with cartilaginous surface defects, including 12 males and 5 females. The average age of patients was 29 years ranging from 18 to 45 years. The defects were located at 10 left knees and 7 right knees. The functional status of patients were evaluated according to the Brittberg-Peterson scoring scale system, the results were average 80.65?9.69 points ranging from 65 to 105. 3 patients had no an obvious history of trauma, but suffered from the rheumatoid disease; however, the other 14 patients had been injured at the knee joint with pain and followed with muscle atrophy on the thigh. 3 patients experienced interlocking, and 2 had snapping in their knee joints. All the 14 patients with traumatic history had only solitary lesion, the area of local cartilaginous defects at the bearing surface of the lateral femoral condyle was of 2.5-3.0 cm2; the local defects of the other 3 patients were located at the medial femoral condyle with defect area of 2.0-2.5 cm2, which was diagnosed either as chondomalacia or corruption. The procedures of the mosaicoplasty consisted of harvesting osteochondral cylinders from non-weight bearing surface of the knee and then implanting the grafts into the cartilaginous defects under arthroscopy. Results All the patients were followed up for 10 to 20 months (mean, 15 months). The joint mobility recovered to nearly normal. According to the Brittberg-Peterson system, 14 patients had score of 0, and 3 had scores of 2-3 because of mild pain. The follow-up MRI showed adequate cartilaginous coverage in the original lesions and excellent position of the cylindrical osteochondral grafts. Conclusion The autologous osteochondral mosaicplasty is proved to have good and reliable clinical results for the cartilaginous defects in the knee bearing surface.

0.05). Measured by KT-1000 arthrometer, the posterior tibial translations in the group of the uni-bundle at 0? and 30? flexion were (5.9?0.4) mm and (6.2?0.5) mm; but the posterior tibial translations in the group of the double-bundle at 0? and 30? flexion were (3.5?0.3) mm and (4.0?0.4) mm. It was of statistical significance (P0.05). Conclusion The clinical results of double-bundle PCL reconstruction is superior to that of the uni-bundle. Arthroscopic double-bundle PCL reconstruction is able to restrict the posterior tibial translation and restore the stability of the knee joint within its full range of flexion.

Objective To explore the effect of the antero-posterior translation of the femur on the maximum knee flexion and the relative movement of the femur for the three different kinds of prosthesis after total knee arthroplasty(TKA), such as posterior-stabilizing, fixed-bearing and mobile-bearing with the PCL retention. Methods 25 patients were selected for each kind of the prosthesis, and the inclusion criterion was based as the knee OA, good-excellent outcome after TKA, the flexion of the knee beyond 90?, and more than one year follow-up. The average age of these patients was 68 years with a range of 63 to 77 years, which involved 32 males and 43 females. The average preoperative knee flexion in the three groups were 77.8??15.1?, 80.1??12.9? and 76.4??12.7? respectively. The roentgenograms were taken both at the knee extension and maximum flexion, then the femur translation and the knee flexion were measured. Results The difference of the knee flexion among three groups preoperatively was of no significance. The maximum postoperative knee flexion in the posterior stabilizing, fixed-bearing and mobile-bearing was 118.0??7.1?,108.7??7.9? and 100.2??8.3? respectively. The analysis of variance showed the difference was of significance (F=32.86, P=0.0001). The relative movement about the femoral prosthesis in the three groups were (6.3?2.5) mm, (1.2?4.6) mm and ( 4.7?3.7) mm respectively (the posterior movement was positive, and the anterior was negative). The difference was of significance(F=57.71, P=0.0001). The femoral antero-posterior translation was proved to have correlation with the maximum knee flexion. Conclusion The femoral translation among three groups are different in manner, accordingly, the maximum knee flexion was different too.

Objective To provide an essential features of the knee for the prothesis design more suitable in Chinese. Methods 240 knees of 120 healthy Chinese adults were selected on trial, with an average age of 30.6 years (range, 21 to 40 years) and an average height of 1.68 m ranging from 1.60 m to 1.75 m. Each individual was asked to do deep flexion activities. Fluoroscopy were used to determine accurately the weightbearing kinematics in vivo of 240 knees at different position. The anterior articular surface of the femoral condyle was designated as the "extension facet"(EF), while the posterior surface as the "flexion facet"(FF). Their centers are labelled as EFC and FFC respectively. The distances between the ipsilateral posterior tibial cortex and the center of the posterior femoral condylar circles at different position were measured by drawing a line through the most protruding points in the medial and lateral tibial subchondral bony landmark. A second line was drawn perpendicular to the first and tangent to the posterior tibial cortex. The distance d1 and d2 were measured perpendicularly from FFC and EFC to the second line respectively. The change of d1 and d2 in different positions denoted the relative movement between the tibia and femur. The data were used by ANOVA analysis containing two factors with SAS software. Results The difference of sex and side had no influence on the relative movements between the tibia and femur. In normal adults, the range of relative motion at the medial and lateral condyle during deep flexion was (1.4?0.3) mm and (15.9?4.7) mm respectively. Conclusion The lateral condyle undergoes posterior translation including sliding and rolling significantly during the deep flexion that leads to the relative axial rotation of the tibia to the femur.

Objective In order to investigate the effectiveness of unique cyclic biomechanical stretch on proliferation, alkaline phosphatase (ALP) activity and osteopontin (OPN) mRNA of colonal murine osteoblast-like cell line MC3T3-E1 in three-demensional culture. Methods Gelatin sponges with a size of 2.00 cm?2.00 cm?0.25 cm were used as the three-demensional culture vector of MC3T3-E1, 100 ?l cell suspension was applied to the surface of sponge, the cell number was 1.25?105. The gelatin sponges could be stretched to 5% with 60 cycles/min and 15 min/h on computerized bio-stretch controller. At 2, 4, 6, 8 and 10 d after stretch stimulation, three samples were collected at each time point from the stretch and con-trol group respectively. Cell counting, activity assay of ALP both of cells and medium as well as OPN mRNA measurement were carried out. Results The cell number of the stretch group was more than that of control group from 2 d (P

Objective To investigate the influence and clinical significance of knee lateral thrust gait to femorotibial angle and lateral joint space in the patients with knee varus deformity. Methods 44 patients (male 10, female 34; range 31-60 years old, mean 41 years old) with knee varus deformity and lateral thrust involved in this study. The femorotibial angle and lateral joint space were measured on the standing anteroposterior film (single-foot loading and double-feet loading) of knee in order to compare the changes of them. The double-feet loading film simulated the corresponding relationship between thighbone and tibiae at double-support time, as early knee lateral thrust. The single-foot loading film simulated the corresponding relationship between thighbone and tibiae at single-support time, as late knee lateral thrust. The changes of femorotibial angle and lateral joint space in the two positions showed the changes of corresponding relation between thighbone and tibiae during knee lateral thrust. Results The mean femorotibial angle was 188.50??4.48? and 185.50??4.46? at the time of single-foot loading and double-feet loading respectively. It indicated that the femorotibial angle was increasing at the time of single-foot loading. The mean width of lateral joint space was (9.92?0.86) mm and (7.70?0.78) mm at the time of single-foot loading and double-feet loading respectively. It demonstrated that lateral joint space was widening more at the time of single-foot loading. The result suggested the lateral thrust of knee led to these changes. The increasing of femorotibial angle meant an increase of knee adduction moment during gait. The increasing of lateral joint space led to lateral structures chronic instability. The increased knee adduction moment and lateral structures chronic instability were the important mechanisms for degeneration of knee medial department. Conclusion The knee lateral thrust gait results in the augments of femorotibial angle and lateral joint space. These lead to the increase of the load on knee medial compartment, lateral structures chronic instability and varus deformity increasing. Lateral thrust might cause aggravation of knee varus and gonarthrosis at knee medial compartment.

Objective To explore the accurate position for the intersect between the short axis of the tibial tray and patellar ligament through studying the relationship among the femoral epicondylar(FE) axis, posterior femoral(PF) axis, posterior tibial(PT) axis, patellar(PAT) axis and patellar ligament(PL). Methods Magnetic resonance imaging (MRI) scans of 40 knees are included in this study. Using the computer workstation, these axial scans were used to construct the FE axis,PF axis, PT axis, PAT axis and PL. Angles between the axes of the selected landmarks were calculated, and linear regressions were performed to assess the relationship between the axes. Template of the tibial tray were positioned along both the FE axis and PT axis and the resultant points of patellar ligament intersection were recorded, and the difference of the intersect was analyzed with the matched t test. Results Strong relationship were found between the FE and PAT axes(1.8?? 3.6?, R2=0.70), as well as between the FE and PF axes(6.1?? 3.0?, R2=0.79). When the tibial template was aligned along the FE axis, 65% of the cases were in an ideal position, and the intersect is at the 10%-60% width of the patellar tendon. When the PT axis was used, 35% were optimal, and the intersect is at the -15%-35% of the width. And the difference in the mean value of the intersect is of statistical significance. Conclusion During total knee arthroplasty, if the short axis of the tibial tray is aligned with the intersects of the PL between its midpoint of the medial third to a half of its entire width, the rotation of the tibial component will fit the FE and PAT axes closely, so the component's position is appropriate.