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 examine osteopontin (OPN) levels in both synovial fluid and articular cartilage of patients with primary knee osteoarthritis (OA) and to investigate their relationship with severity of the disease. Methods Fifty patients with knee OA and 10 healthy controls were enrolled in this study.There were 15 males and 35 females with an average age of 61.8±7.4 years in OA group. The control group included 4 males and 6 females with an average age of 63.2±6.0 years. Mankin score were taken to determine the disease severity of the affected knee. The radiographic grading of OA in the knee was performed using the Kellgren-Lawrence criteria. OPN levels in synovial fluid were measured using enzyme-linked immunosorbent assay. OPN levels in articular cartilage were assessed by immunohistochemical methods. Results Compared to healthy controls, the knee OA patients had higher OPN concentration in synovial fluid ([4519.60±1830.37] pg/ml vs. [1179.70±303.39] pg/ml) and articular cartilage([0.60±0.06] vs. [0.43 ±0.07]). In addition, synovial fluid OPN levels showed a positive correlation with articular cartilage OPN levels (r=0.411,P=0.003). Subsequent analysis showed that the OPN levels in synovial fluid significantly had been correlated with severity of disease using Kellgren-Lawrence criteria (r=0.581, P＜ 0.001). Furthermore,the levels of OPN in the articular cartilage also were correlated with disease severity using Mankin score (r=0.675, P＜ 0.001).Conclusion The data suggest that OPN in synovial fluid and articular cartilage is related to progressive joint damage and could be a predictive biomarker respect to disease severity and progression in knee OA.

Objective To analyze the effect of acromio-humeral interval on the occurrence of subacromial impingement syndrome (SIS) after the clinical application of clavicular hook plate in acromioclavicular joint dislocation (Tossy Ⅲ). Methods From July 2005 to October 2008, 63 cases of acromioclavicular joint dislocation (Tossy Ⅲ) were treated with clavicular hook plate. There were 48 males and 15 females with an average age of 33.6 years (range, 21-53 years). The relationship of the acromio-humeral interval (AHI)were analysed between the two groups by X-ray measurement. The AHI and plate-humeral interval (PHI)were measured on X-ray film to detect difference between the two groups. Results After the operation, all t he 63 cases were divided into two groups according the occurrence of SIS. There were 14 cases in the group of SIS and 49 cases in the group without SIS. The mean follow-up was 12.2 (average, 6-15) months.The average AHI of was (8.5±2.1) mm and (9.7±2.6) mm in the group of SIS and the group without SIS respectively. The difference between the two groups was statistically significant. The average PHI of the group of SIS and the group without SIS was (6.1±2.8) mm and (6.8±2.4) mm respectively. There was no difference between the two groups. After removal of the clavicular hook plate, the clinical sign disappeared in the group of SIS. According the Karlsson scoring system, the excellent and good rate of the shoulder function was 100%. Conclusion The occurrence of SIS after the clinical application of clavicular hook plate has related to the width of the subacromial interval. The syndrome could be treated by the removal of clavicular hook plate.

Objective To analyze the possible reasons of failed surgical treatment of acetabular fractures. Methods Various methods were used for positive patient identification, including according to Matta's X-ray assessment and Merle d'Aubigne & Postel hip function score of clinical standards for classification of acetabular fracture reduction surgery were not satisfied or not carried out a reduction and fixation,the clinical evaluation of hip joint as a "bad", occurrence of femoral head subluxation or dislocation, femoral head necrosis and other serious complications. From February 2000 to February 2008, 22 patients including 14 males and 8 females with an average age of 38.6 years (range, 18-72 years) were considered as failed cases. Results 45.5% of these cases were posterior wall fractures which were not given any fixation, 27.3% of them were posterior column fractures which were not fixed, 13.6% of them whose reduction and fixation of anterior wall fractures were not satisfied, and 9.1% of them were anterior column fractures which needed fixation. One case should take open reduction and iternal fixation instead of THA. The rate of misdiagnosis and mistaken diagnosis were 90% if only X-ray evaluation was made and this rate decreased to 8.3% if computed tomography was taken. The rate of wrong selection of operative approach was 100% in 10 cases of misdiagnosis, and which was 58.3% in 12 cases of correct diagnosis. In the 5 patients with correct diagnosis and selection of operative approach, the reasons of failed surgical treatment were due to imperfect surgical skills in 3 cases, and inappropriate fixation patterns in 2 cases. Conclusion The causes of the failure of surgical treatment for acetabular fracture might include preoperative missed diagnosis and misdiagnose, inappropriate approach, and an unreasonable internal fixation with unskillful technique.

Objective To investigate the effects of serum cobalt ion concentration on the liver, kidney and heart in mice. Methods Forty 4-week-old male ICR mice were randomly divided into four groups saline were given by intraperitoneal injection once per day for 3 weeks. The body weights of the mice were recorded every 3 days to ensure the correct doses of cobalt chloride. Blood samples for testing were taken at day 4, week 1, week 2 and week 3. Serum cobalt ion concentrations were measured in all samples whereas other serum biochemical variables, including aspartate aminotransferase (AST), alanine transaminase(ALT),blood urea nitrogen (BUN), creatinine (Cr), and creatine kinase (CK) were evaluated at week 1, 2 and 3. After killing the mice at week 3, the heart, liver and kidney were collected for pathological evaluation. Results Serum cobalt ion concentration was different between the groups. High-dose cobalt chloride significantly increased AST, ALT and CK concentrations, the concentrations increasing in parallel with treatment duration.Pathological evaluation showed that high-dose cobalt chloride had toxic effects on the heart and liver, however no significant effect was apparent in the kidney. Conclusion High-dose cobalt ion concentration in serum has toxic effects on the heart and liver, but no significant effect on the kidney in mice.

Objective To investigate the clinical results of posterior cruciate ligament (PCL) reconstruction by double bundle-double tunnel Y-shape of the anterior tibialis tendon allograft. Methods From March 2001 to January 2008, 47 patients underwent PCL reconstruction were included. The allogeneic adult anterior tibialis tendon was prepared into the Y-shape double bundles with the length of 130 mm; A bundle was defined as A-side; B-side was two short bundle (B1, B2 bundle). A bundle was 70 mm in length with a diameter of 10-12 mm. B1 bundle (anterolateral bundle) was 55 mm long with a diameter of 6 mm; B2 bundle(posteromedial bundle) was about 50 mm with a diameter of 6 mm. The allograft ligament was installed through the antero-medial approach. Absorbable interface screws were fixed in the tibial tunnel firstly, and then in the femoral tundles. When being fixed, anterolateral bundle was in flexion of 90°, postero-medial bundle was in 30°. Assisted exercise with knee an angle-locked walking aid had continued for 8-10 weeks. Results The average operating time were 45 min. The average follow-up time was 49.5 months. Preoperative Lachmann was positive in all cases while Lachmann was negative in 39 cases, weakly positive in 5 cases, and positive in 4 cases postoperatively. Post-operative KT-1000 testing, Lysholm score and Tegner activity levels has improved significantly compare with the pre-operative ones. Conclusion The double folded bundles of adult anterior tibialis tendon has sufficient length and diameter for posterior cruciate ligament reconstruction with power tension. The methods of ligament passing through the tunnel has improved to ease the procedure.

Objective To evaluate the efficiency of free myocutaneous flap transfer for the treatment of refractory post-traumatic osteomyelitis of the lower leg and foot. Methods Eleven patients with refractory post-traumatic osteomyelitis of the lower legs and feet were treated between February 2004 and December 2007. There were 9 males and 2 females. The average age was 3.5 years. All patients had at least four to five unsuccessful surgical procedures and prolonged antibiotic treatment prior to presentation. The mean duration of osteomyelitis was 26 months (12-47 months). According to the Ciemy-Mader classification, there were 3 cases for ⅢA, 2 for ⅢBL, 4 for ⅥA and 2 for ⅥBL. After radical debridement, free myocutaneous flaps were immediately performed. Nine latissimus dorsi and 2 rectus abdominis myocutaneous flaps were used.External fixation was applied in 6 patients with skeletal instability due to tibial defects. Results An average follow-up was 3.5 years. Two cases suffered partial necrosis and were managed successfully with split-thickness skin grafts later. In 4 patients of presenting segmental bone defect, autogenous bone grafting was applied in one patient and achieved consolidation after 5 months; bone transplantation in 2 patients and achieved consolidation after 8 and 10 months; and vascularized fibula graft in one patient in whom the gap of the tibia was about 10 cm and achieved consolidation after 4 months. The other 7 patients of this group achieved bone consolidation without bone graft. Conclusion The cornerstone of the treatment of chronic osteomyelitis was to be the radical debridement of all involved necrotic and infected soft tissue and bone.The free myocutaneous flaps transfer which has the advantage of obliteration of dead space and stable coverage of the defect was a safe and viable treatment option in chronic osteomyelitis of the lower leg and foot.

Objective To evaluate the osteogenic characteristics of an injectable silk fibroin (SF) enhanced calcium phosphate cement (CPC) composite loaded with recombinant human bone morphogenetic protein-2 (rhBMP-2) on lumbar interbody fusion in sheep. Methods Twenty-four mature sheep were randomly divided into two groups. Each sheep underwent L1.2, L3.4 and L5.6 lumber interbody fusion, and the three disc spaces were randomly implanted with three of the following materials: SF/CPC, CPC/rhBMP-2, SF/CPC/rhBMP2 and autogenous iliac crest bone. One group was killed at 6 months and the other at 12 months. The fusion segments were observed and analyzed by manual palpation, CT scan, undestructive biomechanical testing, undecalcified histology, and histomorphology. Results The fusion rates of SF/CPC, CPC/rhBMP-2, SF/CPC/rhBMP-2 and autogenous bone assessed by manual palpation were 0, 33.33%, 55.56% and 77.78% respectively at 6 months. At 12 months, the fusion rates improved to 11.11%, 44.44%, 77.78% and 77.78%, respectively.The biomechanical results showed that fusion stiffness was significantly greater in autograft compared with SF/CPC/rhBMP-2, CPC/rhBMP-2, and SF/CPC in 4 degrees of freedom (flexion, extension, right bending, and left bending) at 6 months. The SF/CPC/rhBMP-2 composite showed similar stiffness as autograft, which was significantly greater than CPC/rhBMP-2 and SF/CPC at 12 nonths. Both CPC/rhBMP-2 and SF/CPC/rhBMP-2 showed significantly greater stiffness at 12 months compared with that of at 6 months. The results showed that bone volume was significantly greater in autograft compared with SF/CPC/rhBMP-2, CPC/rhBMP-2, and SF/CPC at 6 months. There was significant difference among ceramic residue among SF/CPC, CPC/rhBMP-2 and SF/CPC/rhBMP-2, with SF/CPC the greatest and SF/CPC/thBMP-2 the least. At 12 months, the bone volume of SF/CPC/rhBMP-2 composite was comparable with autograft, and greater than that of CPC/rhBMP-2 and SF/CPC. The bone volume of SF/CPC, CPC/rhBMP-2 and SF/CPC/rhBMP-2 was significantly greater at 12 months than that of at 6 months. The ceramic residue of SF/CPC, CPC/rhBMP-2 and SF/CPC/rhBMP-2 were significantly decreased. Conclusion The SF/CPC/rhBMP-2 composite had excellent osteoconduction and osteoinduction, and balanced degradation and osteogenesis, which may be a kind of ideal bone grafts in spinal fusion.

Objective To identify prognostic factors and imply the appropriate management of pulmonary metastases from osteosarcoma. Methods Data were obtained retrospectively from 99 osteosarcoma patients with pulmonary metastases who received systemic treatments and followed up in Department of Orthopedic Oncology of Peking University People's Hospital from January 2000 to July 2008. The mean followup time was 24.45 months (range, 13-91 months). The average age of the patients at diagnosis was 20.39 years (range, 7-68 years); the male female ratio was 65:34. All the patients had undergone resection of tumors, and 93 of them had received neoadjuvant chemotherapy. Pulmonary metastases were found in 16 patients at diagnosis of osteosarcoma, in 47 patients during chemotherapy and 36 patients after the whole treatment. The age of patients, the number of pulmonary metastases, the time of appearance of pulmonary metastases,extrapulmonary metastases, the response of primary tumor to chemotherapy and management of pulmonary metastases were analyzed. Results The interval between the diagnosis of osteosarcoma and pulmonary metastases ranged from 0 to 74 months with the mean time of 9.05 months. The 1-year, 2- and 5-year cumulative survival rates were 87.4%, 56.8% and 23.4% respectively in the study, with the median survival time of 25 months. Univariate analysis showed the significant factors included the time of appearance and the management of pulmonary metastases. Cox regression analysis revealed that the time of appearance of pulmonary metastases was the only prognostic factor. There was no significant difference between age, number of pulmonary metastases, extrapulmonary metastases and response of primary tumor to chemotherapy.Conclusion Characteristics related to the time of appearance of pulmonary metastases and surgical management especially as pulmonary resection appear to be more predictive of a successful outcome.

Objective To compare the clinical outcome of external fixation device with Kirschner wire or fragment fixation pin with mini plate and screw fixation in treatment of metacarpal and phalangeal articular fracture dislocation. Methods From October 2002 to March 2008, 106 patients with metacarpal and phalangeal articular fracture dislocation were randomly divided into A and B group. The 53 patients in A group were treated with external fixation device with Kirschner wire or fragment fixation pin. There were thumb injury in 24 cases, fracture-dislocation of proximal interphalangeal joint(PIP) in 36 cases, fracture-dislocation of metacarpophalangeal joint (MP) in 17 cases. The 53 patients in B group were treated with mini plate and screw fixation. There were thumb injury in 22 cases, fracture-dislocation of PIP in 30 cases, fracture-dislocation of MP in 23 cases. Duncan rating criteria were used to compare finger range of motion. Results The mean follow-up of 16.8 and 17.5 months in A group and B group. According to Duncan rating criteria, there were excellent in 33 cases, good in 16, fair in 3, and poor in 1 case. The excellent and good rate was 92.5% in A group. There were excellent in 30 cases, good in 17, fair in 5, and poor in 1 case. The excellent and good rate was 88.7% in B group. In A group, 1 case of wound infection was found. The average arc of motion of thumb joint was 134°±21° while the average arc of motion of other fingers was 248°±19°. In B group, no wound infection occurred. The average arc of motion of thumb joint was 122°±18° while the average arc of motion of other fingers was 225°±17°. Conclusion External fixation device with Kirschner wire or fragment fixation pin was better than the application of mini plate and screw fixation in treatment of metacarpal and phalangeal articular fracture-dislocation.