Objective To summarize the managements for acute injury of kne e posterolateral corner structure, and to evaluate the clinical results. Methods 27 cases of acute posterolateral corner injury of the knee were treated by eith er repair or reconstruction, according to the type of injury. The posterolateral stability of the knee was evaluated after follow-up of more than one year. Res ults One year after operation, there was no varus knee instability in full exten sion. At 30-degree flexion, one-degree varus instability was found in one case , but with firm endpoint. No varus instability was found in other cases. Compare d with the uninjured side, leg external rotation slightly increased in three cas es, remained the same in sixteen cases, and decreased in eight cases. Conclusio n First stage treatment of acute posterolateral corner injury of the knee is rel iable for the restoration of stability.

Objective To explore the technique of arthroscopic treatment of diffused pigmented villonodular synovitis, and to evaluate its clinical results. Methods 32 cases of diffused pigmented villonodular synovitis were treated by arthroscopic total synovectomy, using routine anterior approach, combined with posteromedial, posterolateral and trans-posterior-septal approach. There were 23 males and 9 females with an average of 31 years (range, 11 to 57 years). The history lasted from 9 to 39 months (mean, 27 months). 12 of the patients had been operated and recurred. Debridement of the synovium in the posteromedial and posterolateral chambers, and excision of the lesion outside the joint were emphasized. Systematic rehabilitation program were followed. The patients were followed up for 13 to 47 months, and were evaluated for pain, swelling, effusion, range of motion, and function of the whole leg. Results One year after operation, there was slight pain in 2 cases and slight swelling in 1, but no effusion was found. The range of motion was 143??5.1? on average. At the last follow-up, 23 cases received MR examination. No recurrence was found in all cases but one suspected beneath the posterior horn of the medial meniscus without symptoms. According the International Knee Documentation Committee(IKDC)criteria, subjective knee score was 63.4?5.1 and 87.9?4.9, and the Lysholm score were 35.6?4.7 and 86.3?5.6 respectively before surgery and at the last follow-up. 3 cases with postoperative knee instability were subjected to anterior cruciate ligament reconstruction because of its deficiency 3-5 months after synovectomy. Conclusion In case of diffused pigmented villonodular synovitis of the knee joint, arthroscopical total synovectomy is able to prevent recurrence and to assure the good surgical results. The procedure is minimally invasive, and useful to restore knee function.

Objective To introduce the method of knee posterolateral complex reconstruction with the long head of biceps femoris tendon, and to evaluate the short-term outcomes. Methods Anatomic reconstruction of the chronic posterolateral complex injury of knee joint in 23 cases, were performed with the long head of the biceps femoris tendon from February 2001 to November 2002. All of the patients complained of knee instability with abnormal gait, all of which were associated with other knee ligament injury. With retention of the distal attachment or insertion of the long head of the biceps femoris tendon, a distally pedicled tendon slip was made 8-10 mm of width and 16-18 cm of length. Then the tendon slip was divided longitudinally into halves. The posterior half was folded to reconstruct the popliteofibular ligament and popliteal tendon, with the femoral insertion at the anatomical attachment site of the popliteal tendon, the free end fixed into the tunnel at the posterolateral corner of the tibial plateau. The anterior half was folded to reconstruct the lateral collateral ligament, with the femoral insertion at the anatomical attachment site of the lateral collateral ligament, and the free end fixed into the tunnel or sutured to the fibular head. Results The posterolateral stability of the knee was evaluated in more than 6 months follow-up, mainly through examination of knee varus instability and leg external rotation range. 6 months after operation, there was no varus knee instability in full extension. At 30? flexion, one-grade varus instability was found in 2, but with firm endpoint, no varus instability was found in other cases; external rotation increased in 2, remained the same in 16, and decreased in 5 compared with the healthy side. One year after operation, the stability of the posterolateral corner of the knee had no change compared with that of the 6 months examination. Conclusion Simultaneous reconstruction of knee lateral collateral ligament, popliteofibular ligament, and popliteal tendon with the long head of biceps femoris tendon is effective to restore posterolateral stability of the knee joint.

BACKGROUND: Anterior cruciate ligament reconstruction is the major treatment for anterior cruciate ligament injury. Studies on anterior cruciate ligament reconstruction with hamstring tendons developed rapidly. OBJECTIVE: To summarize anatomy, biodynamics and surgery approaches of anterior cruciate ligament, and the progress of anterior cruciate ligament reconstruction with hamstring tendons. RETRIEVAL STRATEGY: Pubmed database was undertaken to identify relevant articles on anterior cruciate ligament reconstruction with hamstring tendons published from January 1990 to October 2007 with the key words of "anterior cruciate ligament, hamstring tendons, reconstruction, tendon regeneration, bone tunnel enlargement" in English. Ninety-two articles were selected primarily, and checked by reading titles and abstracts. Inclusive criteria: articles on anterior cruciate ligament reconstruction with hamstring tendons were included. Excusive criteria: articles with different aims and repetitive contents were excluded. Totally 42 articles were included, of which 2 articles were on animals, 2 articles on system evaluation/Meta analysis and 38 articles on clinical research. LITERATURE EVALUATION: Of them, 22 articles were on anatomy, biodynamics, surgery approaches and clinical results of anterior cruciate ligament, 9 on bone tunnel enlargement of anterior cruciate ligament after reconstruction and 11 on regeneration of hamstring tendons after harvest. DATA SYNTHESIS: With the deep understanding of double-bundle dissection and biodynamics of anterior cruciate ligament and bad control of single-bundle reconstruction on rotary stability, double-bundle anterior cruciate ligament reconstruction with hamstring tendons has become the major treatment. Bone tunnel enlargement of anterior cruciate ligament after reconstruction is multifactorial process of biology and biodynamics, possibly resulting in reduction in primary stability after reconstruction and severe problems in graft fixation in revision surgery. Most hamstring tendons (first selected graft of double-bundle anterior cruciate ligament reconstruction) can regenerate, and partially recover its function, which determined its foundation for anterior cruciate ligament reconstruction used by orthopedists. Bone tunnel enlargement of anterior cruciate ligament after reconstruction still deserves further studies. CONCLUSION: Double-bundle dissection and biodynamics of anterior cruciate ligament lay the foundation for improving surgery scheme. Double-bundle anterior cruciate ligament reconstruction can better control rotary stability of knee joint.

Injury to anterior cruciate ligament (ACL) is the most common lesions of the knee joint. Reconstruction of ACL has been the primary treatment for the instability of the knee. Compared with the traditional reconstruction with patellar tendon, the hamstring tendon has many advantages, such as less damage to the donor site and less incidence of antero-patellar or kneeling pain. This paper highlights the basic and clinical research on ACL reconstruction.

Objective The purpose of this study is to evaluate the results of double-bundle anterior cruciate ligamen (ACL) reconstruction with remnant preservation and tensioning in acute stage. Methods Fifty-six cases of acute ACL injury were treated with double-bundle ACL reconstruction and tibial remnant preservation and tensioning. The double-bundle reconstruction is performed in a four-tunnel manner with eight-strands of hamstring tendon graft. The tibial remnant was tensioned with PDS sutures pulling through the femoral tunnel for the deep bundle. Fifty-three were followed up for a minimum of two years and evaluat-ed according to IKDC and Lysholm rating scale. Results At the last follow-up, all patients had negative Lachman test. KT-1000 examination in 25° knee flexion showed an average side-to-side difference of anterior laxity of (-0.44±1.53) mm compared with (8.01 1.83) mm before surgery (t=37.03, P=0.0001). Twenty-nine (54.7%) patients showed less than 0 mm side-to-side difference, which indicate a more stable or tight status of the injured knee compared with the normal side; 24(45.3%) patients showed 0 to 2 mm laxity. All patients showed negative pivot shift test. Forty-eight patients showed normal range of motion; 2 patients had 5° flexion deficit, 1 patient had less than 5° flexion deficit and 2 patients had 5° hyper-extension loss. In IKDC e-valuation 51 patients (96.2%) were graded as normal and 2 patients (3.8%) were graded as nearly normal. The IKDC subjective score was 95.6±3.1, and the Lysholm score was 94.8±2.9. The average Tegner score was 7.3 before injury and 7.1 at last follow-up. Conclusion Double-bundle ACL reconstruction with rem-nant preservation and tensioning in acute stage could get 96.2% normal and 3.8% nearly normal rates ac-cording to the IKDC scale at a minimum of two year follow-up.

Objective To evaluate and compare the clinical effects of forward and reverse anterior cruciate ligament (ACL) reconstruction through the arthroscopy. Methods From April 2008 to August 2009,97 cases with simple ACL injures were treated with eight strands of hamstring tendons in way of two-bundle and four-tunnel reconstruction. The patients were randomly divided into two groups according to the number of hospital admissions: odd numbers (A group, 47 cases) were treated with forward double-bundle reconstruction and even (B group,50 cases) were treated with reverse. The grafts were fixed with a suspension technique by mini-plates and mini-buttons. Mean follow-up exceeded one year. The function of knee joint were assessed by the IKDC, Lysholm and Tegner rating scale. Results Mean follow-up was 13.71 months.At the last follow-up, 2 patients in A group had a 10°extension deformity and 5 had a less than 15° flexion limitation. All patients in B group showed normal knee extension, and 4 had a 5° flexion limitation. According to Lachman test, there were one case with one plus positive and one with two plus positive in A group,and one with two plus in B. KT-1000 examination (30° flexion and 30 N) showed the side to side mean difference of anterior knee laxity was (1.04±1.11) mm in A group and (0.86±1.12)mm in B. According to objective IKDC evaluation, the results were graded as normal or nearly normal in 46 patients in A group and 48in B. There were no statistical differences in the IKDC, Lysholm, and Teguer scores between two groups.Conclusion Forward or reverse ACL double-bundle reconstruction with eight strands of hamstring tendons can both restore knee stability, and there is no significant deviation between the two techniques.

Objective The purpose of this study is to evaluate the relevance of the recovery of proprioception function and the reservation of residual torn ligamentous fiber in the anterior cruciate ligament (ACL)reconstruction.Methods A retrospective study was carried out in 65 cases of ACL injury,who were treated with double-bundle ACL reconstruction and tibial remnant preservation and tensioning.All the patients were divided into four groups according to the degree of tibial residual fiber observed in the operation,no residual fiber was found(Group A),the length of the residual fiber was less than one third of the normal ACL(Group B),the length of the residual fiber was more than one third less than two thirds of the normal (Group C),the length of the residual fiber was more than two thirds of the normal(Group D).After one year follow-up,the passive angle reproduction test was performed with magnetic angle instrument in 3 flexion ranges(flexion of 90°-60°,60°-30°,and 30°-0°).All the results were contrasted among the four groups by statistical methods.Results In the passive angle reproduction test of the 3 flexion ranges,Group A and B showed a significant difference between the test side and control side(P＜0.05),and Group C showed a significant difference between the test side and control side at the flexion of 30°-0°(P＜0.05),but Group D showed no significant difference at the 3 flexion ranges(P＞0.05).Conclusion During double-bundle ACL reconstruction,with the reservation of tibial residual tom ligamentous and tensioning may have a good effect on the recovery of proprioception function of the knees,which ensure a better functional outcome in the reconstructed knee.

Objective To investigate the relation of event-related potentials (ERPs), which are evoked by calculating and number recognizing stimuli.Methods We examined 26 healthy undergraduate students with double-digit (Arabic numbers) and single-digit modify a prescription problems. While the stimulus information was presented, electroencephalogram (EEG) was recorded simultaneously. ERPs were extracted from EEG data, and then the feature and source of ERPs were analyzed.Results Both calculation and number recognizing induced positive and negative components of ERPs with similar wave form and different latency. The latency of ERPs was conspicuously shorter elicited by number recognizing than by calculating. Grand mean mapping showed the highest amplitudes of ERPs were presented in parietal lobe elicited both by calculating and number recognizing.Conclusion The processing of calculating is more complicated than number recognizing. Calculating and number recognizing may have different electrophysiological background, and they belong to diverse processing course in the brain. Parietal lobe is the functional domains of them.

Objective To introduce the arthroscopic treatment of acute tibial insertion avulsion fracture of posterior cruciate ligament through double posteromedial portal and "Y" shaped bony tunnel, and to evaluate the clinical results. Methods 33 cases of acute tibial insertion avulsion fracture of posterior cruciate ligament were treated arthroscopically through routine portal and double posteromedial portal. The high posteromedial portal was 4 cm proximal to the joint line, and the low posteromedial portal was just at the level of the joint line. The posterior cruciate ligament and avulsion bone fragment were held together with two USP 6 Aesculap polyester threads, which were first wrapped around the posterior cruciate ligament from anterior to posterior, and then tied behind the posterior cruciate ligament and over the bone fragment. The "Y" shaped bone tunnel was made with the common opening at the anteromedial aspect of the tibia and the tunnel arms opened backward at the inferomedial and inferolateral side of the tibial bed respectively. The threads were pulled out through the "Y" shaped bony tunnel and fixed on titanic button. With twisting of the button the threads were tightened and the fixation was insured. The patients were followed up for six months. Fracture reduction and union, knee stability, range of motion, as well as the total knee function were evaluated. Results All fractures were united without displacement. Six months postoperatively, except for one case with Ⅰ degree of positive posterior drawer test, no knee instability was detected; knee extension restored to normal in all cases and average range of flexion were 139??4.1?. 10? to 15? flexion limitation was found in 3 cases. The mean Lysholm knee score was 91.4?3.6. Conclusion Arthroscopic treatment of acute tibial insertion avulsion fracture of posterior cruciate ligament is minimally invasive. The procedure through double posteromedial portal is appropriate, the use of "Y" shaped bony tunnel and button twisting are useful to assure the fixation.