Objective To investigate the pathogenesis of pain around the medial site of knee joint in osteoarthritis, the expressions of nerve growth factor (NGF) and substance P (SP) were observed in the synovial membrane of medial, lateral, and suprapatellar sites of knees in osteoarthritis and simple meniscus tear. Methods Synovial tissues were obtained from medial, lateral, and suprapatellar sites of 13 knees (12 patients with an average age of 57 years) with OA at surgery. Synovial tissues as control were harvested from medial, lateral, and suprapatellar sites of 6 knees (6 patients with an average of 52 years) and simple meniscus tear during the arthroscopic operation. The tissues were cut into small fragments, fixed with formalin and then embedded in paraffin. The expressions of NGF and SP in synovium of the knees were detected using immunohistochemical staining. Gless nerve fiber staining was adopted to observe the distribution of nerve fibers in synovium of the knee. Results NGF revealed in granular pattern in the muscular wall of the vessels in synovium. The positive vessel rates of NGF in the medial synovium of knee osteoarthritis (67.2%) were higher than those in lateral synovium (47.6%,P

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.

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 The purpose of this study was to observe the feature of tunnel enlargement after anterior cruciate ligament reconstructions and to investigate the influencing factors and the relationship between bone tunnel enlargement and clinical outcome. Methods There were 103 patients who accepted anterior cruciate ligament reconstructions with autogenous hamstring tendons for follow-up. Magnetic resonance imaging(MRI) offered the possibility of visualizing the bone tunnels from 12 to 18 months after surgery. The width was measured for tibial and femoral tunnel and compared to initial width. The tunnel size was graded to 4 grade depending on the increased width: grade 0(

[Objective]To clarify the precise displacement of the popliteal artery(PA) during knee flexion using magnetic resonance imaging(MRI).[Method]MRI was used in 16 knees at 0? and 90? of flexion to measure the distance between the popliteal artery and the posterior tibial cortex(bone to artery distance,BAD)at two levels corresponding to the levels of osteotomy in total knee arthroplasty(TKR) and in high tibial osteotomy(HTO).The results were analysed using paired-samples t test.[Result]At the level of TKR(0.5 to 1 cm below the tibial articular surface),the mean posterior movement of BAD from extension to 90? of flexion was 1.8 mm(-2～+5 mm) with a statistical significance(P=0.005).At the level of HTO(1.5 to 2 cm below the tibial articular surface),the mean change in BAD 1.4mm(-2～+4mm)was also statistically significant(P=(0.005)).At the two levels,the artery moved toward the tibia in 2 cases,respectively.[Conclusion]Knee flexion may be considered to be a safer position,still there is possible potential popliteal artery injury.

[Objective]To evaluate efficacy and method of arthroscopic meniscoplasty for horizontal tear of discoid lateral meniscus in a short follow-up term. [Method]A series of 27 patients (27 knees) (mean age 32 years, range 6 years to 42 years) who underwent arthroscopic evaluation and treatment of a discoid lateral meniscus between 2002 and 2006 was reviewed. All the patients who were selected had the horizontal type of tear. Of those discoid menisci classified intraoperatively (n=27), 85.2% (n=23) were complete discoid lateral menisci and 14.2% (n=4) were incomplete discoid lateral menisci. No Wrisberg type was noted. Arthroscopic meniscoplasty was performed in all cases. The horizontal tear meant meniscus was divided into two leaves. The auther removed the unstable leaf to the peripheral rim and preserved the stable one. Arthroscopic meniscoplasty was performed in the stable leaf.[Result]All the patients were evaluated at follow-up according to the Lysholm knee Scoring Scale. At follow-up, patients were reviewed to recognize possible of retear and requirement of arthroscopic revision. The knee score of these patients improved from 72.48?4.64 points preoperatively to 92.18?4.52 points postoperatively. Recurrence of tear or requirement of arthroscopic revision was not noted at the final follow-up. [Conclusion]Arthroscopic meniscoplasty of the horizontal tear of discoid meniscus is an effective method.