0.05). But when the flexion exceeded 30?, especially when it exceeded 60?, the displacement in pPc increased markedly, much greater than that of an intact knee (P0.05), while a slight over-restriction may be found at some angles. Conclusion Double-band reconstruction could effectively restrict the posterior displacement of the tibia and restore anteroposterior stability to the knee joint within its full range of flexion. aPc reconstruction could also maintain the posterior stability of the knee, while the result of pPc reconstruction is most unsatisfactory.

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 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.

[Objective]To analyze the reasons of complications in high tibial valgus osteotomy in the varus osteoarthritic knee and its management.[Method]We studied the results of valgus-producing high tibial osteotomies in patients who had medial unicompartmental osteoarthritis and varus malalignment.We performed the operation for 126 patients from January 2000 to October 2004.Twenty-one patients had complications,including four men and seventeen women,with average age of 61 years(ranged:48～64 years).The femorotibial angle was measured on the standing anteroposterior film of knee preoperatively in order to get high accuracy in preoperative planning.A lateral closing-wedge osteotomy was performed,the osteotomy site was stabilized by Giebel blade plate or stepped staple.[Result]The mean duration of follow-up was 7.5 months(ranged,6 to 12 months).There were twenty-three complications(21 patients,16.7%):tibial fracture in four cases,deep-vein thrombosis in five cases,peroneal nerve palsy in three cases,recurrence of varus deformity in six cases,internal fixation failure in four cases(recurrence of varus deformity developed in two patients),a superficial wound infection developed in one patient.[Conclusion]To reduce the incidence of complications in high tibial valgus osteotomy,we should make familiarication with anantomy and take more accuracy in preoperative planning,improve surgical skill as well as appropriate perioperative management.

Objective To evaluation high tibial osteotomy combined with anteromedial transfer of the distal fragment for the treatment of medial and patellofemoral compartmental osteoarthritis of the varus knee. Methods High tibial osteotomy was performed in 30 knees of 24 patients with medial and patellofemoral compartmental osteoarthritis of the varus knee, which was combined with anteromedial transfer of the distal fragment. The patients included 5 males (7 knees), 19 females (23 knees), with the mean age 53 years (range, 49-55 years). All patients were followed-up with footprints to assess the foot progression angle preoperatively and at 6 months to 2 years after the osteotomy. Tibial torsion of these subjects was measured by computerized tomography preoperatively and after the osteotomy. The statistical evaluation was carried out by the paired t test. Results The foot progression angle was 8.95??2.99? preoperatively, and -2.23??4.11? postoperatively during walking. The tibial torsion was 33.77??8.12? preoperatively and 21.27??8.48? after the osteotomy. The statistical evaluation showed foot progression angle and tibial torsion preoperative were significant difference from those postoperative (P 0.05). This result revealed that the decrease of foot progression angle was equal with the decrease of tibial torsion postoperatively. Conclusion High tibial osteotomy combined with anteromedial transfer of the distal fragment may be the effective method for medial and patellofemoral compartmental osteoarthritis of the knee, but it would cause calf and foot internal rotation. The change of foot progression angle and tibial torsion can influence the effect of high tibial osteotomy. The magnitude of anteromedial transfer of the tibial tubercle must be individualized and be devised preoperatively. It is important to evaluate patellofemoral malalignment and to measure the magnitude of tibial internal rotation in operation.

5 cm. Track record of average range of motion and KSS score. Results A total of 27 knees(10.23%) showed HO after TKA, which included type Ⅰ13 knees, typeⅡ8 knees, typeⅢ 6 knees. Average KSS score of typeⅢ was 83.1?1.5. It was lower than normal group(P0.05). Conclusion TypeⅢ HO after TKA impact clinic outcome. Ostephte increases the probability of HO, and NSAIDS decrease the probability. The incidence of HO have no relation with implants.