[Experimental study on improving stability of anchor by adding anchor].

OBJECTIVE: To explore whether anchor placement could improve holding force of anchors under the condition of osteoporosis, in order to solve the problem of clinical treatment for rotator cuff injury associated with osteoporosis. METHODS: Twenty one bone modules, which included 13 males and 8 females aged from 60 to 95 years old with an average of (77.6±10.3) years old, and were divided into three experimental groups named as group A, B and C, and 7 in each group. A single anchor was inserted in group A, two parallel anchors were screwed in group B, and a single anchor was screwed in group C, then after the anchor was pulled out, anchor was screwed back and another anchor was screwed in close to the anchor. X-ray examination was performed in all three groups to observe situation of anchor in osteoporosis module; the maximum axial pull-out force (Fmax) of the three groups was measured. RESULTS: Fmax of group A, B and C was (170.35±31.21) N, (314.47±23.47) N, and(292.74±25.36) N, respectively. Compared with group A, there were statistical difference of Fmax in group B and C(P<0.05), while no difference of Fmax between group B and C(P>0.05). CONCLUSION: In the case of loose anchors in the osteoporosis module, holding force of anchors could be improved by adding anchor, which provide a remedy for single anchor failure in clinical operation.

[Anatomical study on reconstruction of calcaneus fibula ligament].

OBJECTIVE: To measure anatomical data of calcaneofibular ligament (CFL), relevant data of CFL attachment to provide an anatomical basis for CFL reconstruction. METHODS: Twenty-seven adult ankle specimens were selected, including 11 males and 16 females, aged from 22 to 71 years old with an average of (41.6±17.2) years old;9 cases on the left side and 18 cases on the right side. The specimens reserved at least 20 cm above ankle joint and a complete foot, and exclude deformities, fractures, incomplete development and degenerative lesions. CFL was performed detailed anatomical observation, morphological parameters of CFL was measured, and coordinates of fibula side and calcaneal side of CFL in the coordinate axis were measured. The distance between fibula insertion of CFL and fibula tip, distance between calcaneal insertion of CFL and lateral calcaneal nodule, and Angle between CFL and long axis of fibula were also measured. RESULTS: In these 27 specimens, CFL cases were all single bundles and the length of CFL was (32.83 ± 8.19) mm. The center point of fibula attachment in CFL was(2.87± 1.21) mm proximal with a coefficient of variation of 42.16% and (2.08±1.34) mm anteriorly with a coefficient of variation of 64.42%. The center point of calcaneal attachment region of CFL was located on coordinate axis on the distal end (15.32±5.33) mm, with a coefficient of variation of 34.79%, and the posterior part (6.38±2.15) mm, with a coefficient of variation of 33.86%. The distance between center point of fibula attachment and fibula tip was (4.81±0.82) mm. The distance between center point of calcaneal attachment area of CFL and lateral calcaneal nodules was(17.25±3.12) mm. Angle between CFL and fibula axis is (43 ±18)° . CONCLUSION: According to anatomical studies, we could locate the fibula and calcaneal attachment of CFL by anatomical markers around ankle joint. However, the location of CFL attachment has a large variation, and the anatomical characteristics need to be considered in anatomical reconstruction.

[A comparative study of the curative effect of proximal fibular osteotomy and single condylar replacement for the treatment of knee osteoarthritis of different severity].

OBJECTIVE: To compare the clinical effect of proximal fibular osteotomy (PFO) and single condyle replacement (UKA) in the treatment of knee osteoarthritis of different severity. METHODS: From June 2015 to September 2017, 53 patients with knee osteoarthritis were analyzed retrospectively. According to the operation mode, they were divided into PFO group (26 cases) and UKA group (27 cases) . According to Kellygren-Lawrence imaging classification standard：PFO group, 5 cases of gradeⅡ, 11 cases of grade Ⅲ, 10 cases of grade Ⅳ; UKA group, 7 cases of gradeⅡ, 9 cases of grade Ⅲ, 11 cases of grade Ⅳ. The amount of intraoperative bleeding, operation time and postoperative hospital stay were compared between the two groups. The patients were followed up regularly in the outpatient clinic before operation, 3 months after operation and 1 year after operation. The WOMAC score and the angle of tibiofemoral angle at each time point in the same group were compared, and the OMAC score and the angle of tibiofemoral angle at each time between the two groups were compared. RESULTS: Fifty-three patients were followed up for 12 to 24 (16.6±4.8) months. Compared with UKA group, PFO group had less intraoperative bleeding, shorter operative time and shorter postoperative hospital stay (P<0.05) . The scores of pain, stiffness and body function in UKA group were better than those in PFO group (P<0.05) . After 3 months and 1 year, the WOMAC index in PFO group was significantly improved (P<0.05) ; after 3 months and 1 year, the WOMAC index in UKA group was significantly better than that in PFO group (P<0.05) ; after 3 months, the WOMAC index in PFO group was significantly better than that in UKA group (P<0.05) . The tibiofemoral angle of gradeⅡand Ⅲ patients in both groups decreased gradually (P<0.05) ; the tibiofemoral angle of grade Ⅳ patients in UKA group was smaller than that of grade Ⅳ patients in PFO group (P<0.05) . CONCLUSION: Compared with UKA, PFO has the advantages of small trauma, fast recovery and low cost. The curative effect of PFO is equal to or more than UKA in the patients with gradeⅡand Ⅲ knee osteoarthritis. It is an alternative surgical method for the treatment of knee osteoarthritis.

[Treatment for posterior root tear of lateral meniscus through bone tunnel suture under arthroscopy].

OBJECTIVE: To evaluate clinical effects of posterior root tear of lateral meniscus through bone tunnel suture under arthroscopy. METHODS: From January 2012 to December 2014, 23 patients with posterior root tear of lateral meniscus repaired through bone tunnel suture under arthroscopy, including 15 males and 8 females, aged from 19 to 48 years old with an average age of (25.0±4.7) years old; 10 knees on the left side and 13 knees on the right side. Complications were observed, Lysholm score before and after operation at 12 months were used to evaluate clinical results, and VAS score was applied to assess pain relief. MRI was used to check recovery outcomes of lateral meniscus injury. RESULTS: All patients were followed up from 13 to 24 months with an average of (17.0±4.3) months. No injury of vessels, nerve and incision infection occurred. Motion of knee joint of 19 patients reached normal, 4 patients manifested limited activity of knee joint at12 months after operation. Postoperative Lysholm score 88.52±6.48 at 12 months was higher than that of before operation 46.12±7.35; Postoperative VAS score 0.8±0.7 at 12 months was lower than that of before operation 4.3±1.6. CONCLUSIONS: Bone tunnel suture under arthroscopy for the treatment of posterior root tear of lateral meniscus could relieve pain, decrease postoperative complications and obtain good clinical efficacy.

[Biomechanical stability study on different internal fixation for acetabular fracture].

OBJECTIVE: To investigate the biomechanical stability of the acetabular fracture with three different internal fixation methods. METHODS: Sixteen both-column acetabular fracture models were randomly divided into three groups:The specimens of 16 hip joints were randomly divided into 4 groups. Among them, 1 group of complete acetabulum were used as normal control group, and the other 3 groups simulated two column fracture models and were fixed in the following methods, respectively: anterior wall with screw and posterior with plate(SP), anterior wall with plate and posterior wall with screw(PS) and both wall with plate (PP). The degree of fracture displacement and the contact characteristics of the acetabulum were recorded by continuous vertical loading. RESULTS: The mean longitudinal displacement under the load 800 N of SP, PS and PP three groups were (1.92±0.81), (2.09±1.13) and (3.44±0.75) mm, there was significant difference between SP and PP group (P=0.033). And the mean horizontal displacement of SP, PS and PP three groups were(0.63±0.33), (0.77±0.45) and (1.44±0.56) mm, there was significant difference between SP and PP group(P=0.047).Compared with normal control group in the acetabular area under the loading 800 N, the contact area of SP, PS and PP groups were increased by 6%, 9% and 27%, there was significant difference between PP and normal control group (P=0.027). Meanwhile, the mean stress of SP, PS and PP groups were increased by 4%, 29% and 39%, there was significant difference between PP and intact acetabulum group (P=0.003). CONCLUSIONS: Anterior column screw combined with posterior column plate has better biomechanical stability and contact characteristics than other two methods.

[Diagnostic value of MRI for posterior root tear of medial and lateral meniscus].

OBJECTIVE: To explore diagnostic value of MRI on posterior root tear of medial and lateral meniscus. METHODS: From January 2012 to January 2016, clinical data of 43 patients with meniscal posterior root tear confirmed by arthroscopy were retrospective analyzed, including 25 males and 18 females, aged from 27 to 69 years old with an average age of(42.5±8.3)years old;27 cases on the right side and 16 cases on the left side. MRI examinations of 43 patients with tear of posterior meniscus root confirmed by knee arthroscopies were retrospectively reviewed. MRI images were double-blinded, independently, retrospectively scored by two imaging physicians. Sensitivity, specificity and accuracy of MRI diagnosis of lateral and medial meniscus posterior root tear were calculated, and knee ligament injury and meniscal dislocation were calculated. RESULTS: Forty-three of 143 patients were diagnosed with meniscus posterior root tears by arthroscopy, including 19 patients with lateral tears and 24 patients with medial tears. The sensitivity, specificity and accuracy in diagnosis of posterior medial meniscus root tears for doctor A were 91.67%, 86.6% and 83.9% respectively, and for doctor B were 87.5%, 87.4% and 87.4%, 19 patients with medial meniscal protrusion and 2 patients with anterior cruciate ligament tear. The sensitivity, specificity and accuracy in diagnosis of posterior lateral meniscus root tears for doctor A were 73.7%, 79.9% and 79% respectively, and for doctor B were 78.9%, 82.3% and 82.5%, 4 patients with lateral meniscus herniation and 16 patients with cruciate ligament tear. Kappa statistics for posterior medial meniscus root tears and posterior lateral meniscus root tears were 0.84 and 0.72. CONCLUSIONS: MRI could effectively demonstrate imaging features of medial and lateral meniscal root tear and its accompanying signs. It could provide the basis for preoperative diagnosis of clinicians, and be worthy to be popularized.

Femoral tunnel positioning using an anteromedial technique for ACL reconstruction: A radiographic study with a cadaveric model.

BACKGROUND: We studied the anatomic positioning of the femoral tunnel during simulated anterior cruciate ligament reconstruction using an anteromedial portal approach in cadaveric models. METHODS: In thirty cadaveric human knee specimens, simulation of an arthroscopic anterior cruciate ligament reconstruction was performed and the femoral tunnel was drilled using an anteromedial portal. A Kirschner wire was passed into the tunnel and radiographs were obtained. These radiographs were then evaluated in the coronal and sagittal planes. Angles between the axis of the femoral tunnel and the joint line in the coronal plane (alpha, α) or the femoral long axis in the sagittal plane (beta, ß) were calculated for each specimen. The external aperture of the femoral tunnel was defined as the point of exit of the Kirschner wire from the lateral femoral cortex. This was evaluated relative to a prescribed rectangle and coordinate axis, with the radiographic quadrant method of Bernard, to assess the accuracy of femoral tunnel placement. RESULTS: The mean α in the coronal plane was 48.53∘, the mean ß in the sagittal plane was 32.23∘. All of the femoral tunnel external apertures were located outside of the rectangleCONCLUSION: We evaluated the positioning of the femoral tunnel and the external aperture of the femoral tunnel with the anteromedial portal technique. This study provides a reference standard to assess accurately femoral tunnel positioning on postoperative radiographs.

[Effects of tranexamic acid combined with temporary drain clamping on postoperative blood loss in total knee arthroplasty].

OBJECTIVE: To evaluate the efficacy and safety of one dose tranexamic acid combined with temporary drain lamping in primary unilateral total knee arthroplasty. METHODS: Total 160 patients undergoing unilateral primary total knee arthroplasty between January 2012 and December 2013 were randomly divided into four groups(40 cases in each group):group A (the drain was clamped for 2 hours after the operation and the patients received 20 ml physiological saline), group B(the drain was clamped for 2 hours after the operation and the patients received 10 ml tranexamic acid and 10 ml physiological saline), group C (the drain was clamped for 4 hours after the operation and the patients received 20 ml physiological saline) and group D(the drain was clamped for 4 hours after the operation and the patients received 10 ml tranexamic acid and 10 ml physiological saline). The postoperative hemoglobin level, maximum hemoglobin loss, wound drainage, blood loss, the volume of blood transfusion, the number of patients inquiring blood transfusion, venous thrombo embolism rate, and ecchymosis rate were recorded and compared among the four groups. RESULTS: There was no incision infection, severe hypoxia, and symptomatic pulmonary embolism in these groups. There were significant differences in hemoglobin content one day after operation in each group(F=12.26, P=0.000), in the hemoglobin content 7 days after operation in each group(F=20.74, P=0.000), in postoperative drainage in each group(F=38.71, P=0.000);in the amount of invisible red blood cell loss in each group(F=83.41, P=0.000), and in total red blood cell loss in each group(F=102.68, P=0.000). Color Doppler ultrasound examination found that the total incidence of VTE was 3%(5/160) and there were no significant differences in each group(P=0.892). There were no significant differences in postoperative subcutaneous ecchymosis area>1% incidence(P=0.143). CONCLUSIONS: Topical tranexami acid treatment combined with temporary clamping of drain for 4 hours could reduce postoperative blood loss, blood transfusion, and ecchymosis rate without increasing the risk of thromboembolic event after total knee arthroplasty.

Phytoestrogen α-zearalanol exerts antiapoptotic effects in differentiated pc12 cells via oestrogen receptor α.

Our previous studies have demonstrated that phytoestrogen α-zearalanol (α-ZAL) possesses potential benefits in alleviating cell apoptotic death just like oestrogen. However, the underlying mechanism is not fully understood. This study was designed to test the hypothesis that the neuroprotective effect of α-ZAL is mediated by oestrogen receptor (ER) as α-ZAL owns the benzene ring structure may interact with ER. The present results showed a significant increase in apoptosis in differentiated PC12 cells after a 24-hr exposure to amyloid ß-peptide fragment 25-35 (Aß25-35 ), accompanied by decreasing of bcl-2 expression and increasing bax expression, whereas a pre-treatment with α-ZAL ameliorated these changes induced by Aß25-35 . In addition, the α-ZAL-mediated cytoprotection was abrogated by ERα antagonist but not by ERß antagonist. In summary, these data suggest that α-ZAL intervenes against Aß-induced apoptosis via intersecting bcl-2-bax apoptotic pathway in an ERα-sensitive manner.

[Arthroscopic single bundle anterior cruciate ligament anatomical reconstruction with remnant preservation].

OBJECTIVE: To investigate the feasibility and clinical effects of single bundle anterior cruciate ligament anatomical reconstruction with remnant preservation. METHODS: From October 2007 to November 2009, 17 patients (10 male and 7 female, ranging in age from 28 to 62 years, with an average of 39.3 years) with posterior cruciate ligament injuries were treated with single bundle anatomical reconstruction with remnant preservation. Nine patients had the injuries caused by traffic accident; 6 patients caused by falling down; and 2 patients caused by sports injuries. The average time from injury to surgery was 8.5 days (ranging from 2 to 14 days). The international knee documentation committee knee evaluation form (IKDC) and Lysholm were used to analysis the effect of surgery. RESULTS: All the patients obtained the follow-up and the average time was 29.5 months (ranging from 24 to 39 months). There were no complications such as injuries of popliteal fossa artery, tibial nerves or peroneal nerve. Twelve patients had knee joint recovering to normal; 1 patient had stiff joints and was treated with arthroscopic surgery to release after 6 months,who had postoperative flexion lack of 20 degree and straight to normal. Three patients had flexion loss of 5 to 10 degree, and 1 patient had hyperextension limitation of 5 degree. Posterior drawer test in 17 patients and the Lachman test were negative. IKDC scores of the 17 patients achieved normal(16 patients) or near normal(1 patient). IKDC overall score normal in 16 patients (94.1%), close to normal in 1 case (5.9%). The IKDC subjective score was 94.3+/-5.1 and Lysholm score was 94.7+/-3.1 at the latest follow-up. CONCLUSION: The single bundle anterior cruciate ligament with remnant preservation anatomical reconstruction can provide good clinical results.

[Anatomical study on the femoral tunnel anatomy reconstruction of anterior cruciate ligament].

OBJECTIVE: To measure anatomical data of the femoral tunnel anatomy reconstruction of anterior cruciate ligament (ACL), so provide anatomical basis for clinical anatomy reconstruction of ACL. METHODS: There were 30 adults' cadaveric knee specimens. The ACL femoral tunnel was reconstructed through anterior medial approach (AMP) in genuflex position of 120 degree, and was marked by Kirschner. The soft tissue of the specimen was removed and the femoral condyle was split at the middle side. The index including length of the femoral tunnel, the distance from internal opening of tunnel to cortical edge of femoral condyle and vertical distance to the top of femoral intercondylar notch were measured. Then the time position of internal opening of tunnel in the intercondylar notch was recorded, and the location of outside opening of tunnel to the femoral condyle was detected. RESULTS: The mean length of the femoral tunnel was (36.35 +/- 3.14) mm (ranged, 30.65 to 42.35 mm). The distance from internal opening of tunnel to cortical edge of femoral condyle was (17.84 +/- 3.35) mm (ranged, 14.02 to 23.49 mm), vertical distance to the top of femoral intercondylar notch was (14.05 +/- 2.32) mm (ranged, 9.17 to 20.08 mm). According to the way of circular dial,internal opening of tunnel located at 02:30 +/- 00:10 (ranged, 01:50 to 02:50) in the left knee,and 09:30 +/- 0:15 (ranged, 08:30 to 10:40) in the right knee. The outside opening of femoral tunnel located at (3.16 +/- 2.51) mm (ranged, 1.61 to 6.30 mm) to the proximal end of external epicondyle of femur, and (4.25 +/- 2.16) mm (ranged, 1.73 to 8.52 mm) to the posterior of external epicondyle of femur. CONCLUSION: The anatomical features of femoral tunnel for reconstruction of ACL is revealed,which will provide anatomical basis for clinical practice.

[Treatment of proximal radius epiphyseal injuries of O'Brien type III with titanium elastic nail in children].

OBJECTIVE: To investigate the feasibility and clinical effects of titanium elastic nail (TEN) for treatment of proximal radius epiphyseal injuries of O'Brien type III. METHODS: From October 2008 to November 2009,19 patients with proximal radius epiphyseal injuries of O'Brien type III were treated with internal fixation, including 13 males and 5 females with an average age of 8.3 years old ranging from 6 to 12 years. The average time from injury to surgery was 3.5 days (2 to 7 days). The reduction situation after operation was assessed by Métaizeau criteria, and the elbow function after operation were evaluated by Broberg-Morrey elbow score. RESULTS: All patients were followed-up for 8.7 months in average (ranged 6 to 12 months). No infection, TEN brokage, skin bursting and other complications occurrenced. According to Métaizeau criteria, the results were excellent in 7 cases, good in 10 cases and fair in 2 cases. The Broberg-Morrey score rose from preoperative (47.3 +/- 5.1) to (86.6 +/- 6.3) at 3 months followed-up (t=139.17, P=0.0002); the outcome was excellent in 7 cases, good in 9 cases, and fair in 3 cases. CONCLUSION: Internal fixation with TEN in treatment of proximal radius epiphyseal injuries of O'Brien type III has a limited invasion, cosmetic beauty, safety and reliability advantages. This technique provides a reliable alternative in proximal radius epiphyseal injuries of O'Brien type III.

[Treatment of Hoffa fracture using hollow lag screw].

OBJECTIVE: To investigate the operation techniques and clinical effects of hollow lag screws for the treatment of Hoffa fractures. METHODS: From February 2001 to May 2009, 13 patients with Hoffa fractures were treated with hollow lag screws, including 8 males and 5 females, ranging in age from 23 to 45 years, with a mean age of 34.2 years. Six patients had the fractures on the left, 7 patients on the right. According to the Letenneuer type, femur lateral condyle: type I in 3 cases, type III in 2 cases; femur medial condyle: type I in 3 cases, type II in 2 cases, type III in 3 cases. According to the type of fracture, hollow lag screws were used to treat the fracture with different approach. RESULTS: All the patients were followed up, and the duration ranged from 12 to 23 months,with a mean of 16.5 months. All the patients had no complications such as popliteal artery, tibial nerve or peroneal nerve injuries. According to Letenneur knee function score: 10 patients got an excellent result, 3 good. At the half year after operation, the X-ray showed all the fractures had bone union. There were no hollow lag screw loosening, broken or nonunion. CONCLUSION: The clinical effect of hollow lag screw for the treatment of Hoffa fractures is satisfactory. The surgical approach and fixation should be determined by the type of fracture, the location of the fracture line and the size of fracture fragments.

[Treatment of adolescent clavicular fracture with titanium elastic nails].

OBJECTIVE: To investigate the feasibility and clinical effects of titanium elastic nails (TEN) for adolescent clavicular fracture. METHODS: From October 2008 to November 2009, 17 adolescent patients with clavicular fracture were treated with internal fixation, including 11 males and 5 females who ranged in age from 12 to 18 years (mean 15.3 years). The mean time from injury to surgery was 3.5 days (2-7 days). Constant function score before surgery and that 3 months after surgery and shoulder ROM before surgery and that 2 months after surgery were compared. Fracture reduction and healing were followed up by X-rays to analyze internal fixation with the TEN technique. RESULTS: All patients were followed up for a mean of 6.5 months (range 3-8 months), during which no infection, TEN fracture or skin bursting was observed. The Constant score rose from preoperative (45.3 +/- 6.1) to (85.6 +/- 4.3) at 3-month follow up (t = 22.164, P < 0.01),and the shoulder activity degree at 2-week follow up was improved obviosly from preoperative (P < 0.01). X-ray at 12-16 weeks after surgery showed good bone healing and recovery of shoulder function. CONCLUSION: Internal fixation with TEN in the treatment of adolescent clavicular fracture is safe, minimally invasive,reliable and cosmetic. This technique provides a liable ption for the treatment of adolescent clavicular fractire

[Clinical study on the effects of the femoral attachment site of grafts and the tunnel angle on the function of knee joint after anterior cruciate ligament reconstruction].

OBJECTIVE: To investigate the effects of the attachment site of grafts and the tunnel angle on the function of knee joint after anterior cruciate ligament reconstruction. METHODS: From January 2006 to May 2009, 47 patients(32 males and 15 females, ranging in age from 19 to 51 years old, with an average of 35.3 years old) were treated with single-bundle reconstruction of anterior cruciate ligament. Several indexes were measured at the latest follow-up as follow: attachment sites of graft on the femoral condyle were recorded, the femoral tunnel angles on coronal and sagittal planes were measured on postoperative X-ray films. According to the IKDC score, these patients were divided into two groups. In the first group, 38 patients were found the IKDC score more than 90 at the latest follow-up, and in the second group 9 patients were found IKDC score less than 90. By comparing the two groups, the relation of the indexes and postoperative function of knee was analyzed. RESULTS: The IKDC which was more than 90 at the latest follow-up was found in 38 patients, whose femoral attachments site of ACL was positioned at (29.73 +/- 4.31)% (ranged from 16.21% to 53.82%) from the posterior end of Blumensaat's line. IKDC which was less than 90 was found in 9 patients, whose femoral attachments site of ACL was positioned at (46.61 +/- 3.43)% (ranged from 27.18% to 72.34%). There was significant difference between the two groups (P = -0.000 7). The IKDC more than 90 at the latest follow-up was found in 38 patients,whose femoral tunnel angle on coronal plane was (49.5 +/- 4.72) degrees (ranged from 33 degrees to 67 degrees) and on sagittal plane was (31.3 +/- 5.12) degrees (ranged from 11 degrees to 45 degrees) were significantly less than those whose IKDC less than 90 at the latest follow-up on coronal plane was (67.6 +/- 3.09) degrees (ranged from 41 degrees to 81 degrees) and on sagittal plane was (41.2 +/- 5.69) degrees (ranged from 23 degrees to 56 degrees) (P = 0.000 7, P = -0.000 8). CONCLUSION: There is close relation between the attachment site of grafts and the tunnel angle with the function of knee, so in anterior cruciate ligament should be anatomic reconstructed with the anterior medial approach.

[Surgical treatment of thoracolumbar fractures using reduction and short-segment pedicle screw at the fracture level with the approach through para-vertebral muscles].

OBJECTIVE: To evaluate the efficacy and clinical outcome of reduction and pedicle screws fixation at the fracture level with the approach through para-vertebral muscles in treating thoraeolumbar fractures. METHODS: From January 2007 to March 2010,27 patients with thoracolumbar fractures were treated with posterior open reduction and internal fixation with the approach through para-vertebral muscles. There were 19 males and 8 females with the mean age of 36.3 years old (ranged,21 to 57). According to Magerl type, type A2 was in 5 cases, A3 in 14, B1 in 3, B2 in 5. According to Frankel classification of spinal cord injury: grade D was in 6 cases and grade E in 21 cases. X-rays and CT scans were performed after operation. Cobb angle of the injured vertebral segment,the percentage of vertebral compression,and sagittal diameter stenosis rate of the injured spinal canal were observed by radiographic data. Neurological function was evaluated by the Frankel grade. RESULTS: All patients were followed up from 12 to 28 months with an average of 19.6 months. The percentage of vertebral compression, Cobb angle of the injured vertebral segment, spinal canal sagittal diameter stenosis rate were respectively corrected from (46.6 +/- 10.5)%, (18.3 +/- 7.2) degrees, (30.2 +/- 7.2)% to postoperative (5.2 +/- 3.7)%, (5.3 +/- 5.1) degrees, (6.3 +/- 4.2)% and (6.7 +/- 4.6)%, (7.1 +/- 3.1), (7.2 +/- 4.5)% at last follow-up. There were significant difference in above items between preoperation and postoperation (P < 0.05); and there was no significant difference in above items between postoperation and last follow-up (P > 0.05). In aspect of nerve function, 3 cases with Frankel grade D recovered to grade E. CONCLUSION: Using reduction and short-segment pedicle screws fixation at the fracture level through para-vertebral muscles approach is an effective method in treating thoracolumbar fractures. The method has advantages of simple operation,easy establishing screw, short operative time, less blood loss, which can obtain good reduction and stable, reliable fixation after operation.

[Clinical study on second-stage revision in the postoperative infection after total hip replacement].

OBJECTIVE: To study the therapeutic effects and clinical experiences of second-stage revision in postoperative infection after total hip replacement and to explore its security and validity. METHODS: From January 2006 to March 2009, 17 hips in 17 patients (7 males and 10 females, ranging in age from 43 to 75 years, with an average of 58.5 years) were treated with second-stage revision. All the patients suffered from different degrees of hip pain. In bacilliculture of Synovial fluid or peritonsillar tissue, 11 patients showed positive results and 6 patient negative. The intraoperative periprosthetic histopathological examination showed that all the patients had acute inflammation. Eight patients had sinus communicating with prosthesis; 15 patients had increased ESR, and 15 patients had C reactive protein increased. All the patients had osteolysis, prosthesis loosening, and the performance of periosteal reaction in X-ray. All the patients were treated with second stage revision. In the first operation, thorough debridement was perfumed and the prosthesis was removed. Then the prosthesis of antibiotic--loaded acrylic cement was implanted. After giving antibiotics intravenously for 4 weeks, the antibiotics were taken orally for another six weeks. The ESR and C response protein were examined at regular time, and the second-stage revision surgery was perfumed when the ESR and C response protein were normal. The Harris score was used to evaluate therapeutic effects of second-stage revision surgery before and after treatment. RESULTS: All the patients were followed up with an average of 19.5 months, ranged from 12 to 35 months. No complications occurred. Postoperative X-ray showed prosthesis in the correct position. The Harris score increased from preoperative (39.3 +/- 5.6) to postoperative (84.4 +/- 10.3) (t = 15.86, P < 0.01). CONCLUSION: The second-stage revision in postoperative infection after total hip replacement has a good efficacy, safety and reliability advantages. This technology provides an alternative in postoperative infection after total hip replacement.

Age-related alterations in the expression of MTH2 in the hippocampus of the SAMP8 mouse with learning and memory deterioration.

MutT-related proteins degrade 8-oxo-7,8-dihydrodeoxyguanosine triphosphate (8-oxo-dGTP), a mutagenic substrate for DNA synthesis in the nucleotide pool, thereby preventing DNA replication errors. MTH2 (Mut T homolog 2), which belongs to this family of proteins, possesses 8-oxo-7,8-dihydro-2'-deoxyguanosine triphosphatase (8-oxo-dGTPase) activity and appears to function in the protection of the genetic material from the untoward effects of endogenous oxygen radicals. To examine the roles of MTH2 in the aging process, we used the senescence-accelerated prone mouse 8 (SAMP8), which exhibits early aging syndromes and declining abilities of learning and memory. Immunohistochemical and western blot analysis revealed that the level of MTH2 protein in the hippocampus of the SAMP8 mouse progressively decreases beginning from four months after birth, whereas no such change was observed in the control senescence-accelerated resistant mouse 1 (SAMR1). Under these conditions, 8-oxoguanine accumulates in the nuclear DNA in the CA1 and CA3 subregions of the hippocampus of SAMP8 in an age-dependent manner. In SAMR1 mice, accumulation of 8-oxoguanine in the DNA was not observed. These results suggest that the MTH2 deficiency might be one of the causative factors for accelerated aging.

Gossypium herbaceam extracts attenuate ibotenic acid-induced excitotoxicity in rat hippocampus.

Excitotoxicity is one of the most extensively studied processes of neuronal death and plays an important role in Alzheimer's disease. In the present study, the protective effects of Gossypium herbaceam extracts (GHE) on learning and memory impairment induced by excitatory neurotoxin ibotenic acid were examined in vivo using Morris water maze. Furthermore, neuroprotective effects of GHE were investigated with methods of immunohistochemistry and biochemistry. Our data showed that oral administration with GHE at the doses of 35, 70 and 140 mg/kg exerted an improved effect on the learning and memory impairment in rats induced by intracerebral injection of ibotenic acid. To confirm the precise mechanism of memory improvement by presence of GHE, we further investigated the potential protection on the hippocampus. Our findings suggest that GHE afforded a beneficial inhibition on pro-apoptosis proteins expression following ibotenic acid. Additionally, calcium pump activity and calbindin-D28k expression were dramatically increased after GHE treatment, implicating that the modulation of calcium homeostasis could be involved in the mechanism underlying neuroprotection of GHE against ibotenic acid-induced excitotoxicity. These data suggested that GHE could be a potential agent for preventing or retarding the development or progression of Alzheimer's disease.