[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.

[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.