[Objective]To analyze the early diagnosis and treatment of the popliteal artery injury associated with the dislocation and fracture of the knee.[Method]A total of 71 cases of popliteal artery injury associated with the dislocation and fracture of the knee were treated from March 1998 to May 2005.Properative(vascular examization) and operative(methods of arterial repair,venous repair-ligation,anticoagulation-thrombolytic therapy,fracture reduction and internal fixation,fasciotomy) treatment were studied.[Result]Totally 15 cases were primary amputation and 56 cases were performed vascular repair and the fractures and dislocations were reduced and fixed by internal or external fixation.Two cases had thrombosis at the repaired site confirmed by Doppler and had to perform second operation to remove thrombus and repair the popliteal by autograft of the saphena magna vein.At the follow-up,2 cases had chronic osteomyelitis and 2 cases had traumatic arthritis.[Conclusion]It is postulated that a rational and prompt diagnosis and treatment of popliteal artery injury associated with dislocation and fracture around the knee would decrease the adverse effects of ischemia and reduce the overall morbidity.

Disruption of blood supply to the femoral head and subsequent hypoxia are implicated in the pathogenesis of osteonecrosis of the femoral head(ONFH),which frequently leads to the progressive collapse of the femoral head,thus causing degenerative arthritis of the hip joint.But the pathophysiology of osteonecrosis of the femoral head has not been completely elucidated.It is accepted that steroids and alcohol intake are two most common causes of ONFH.Now many theories have been proposed to decipher the etiology and pathogenesis of ONFH,including abnormal lipid metabolism,elevated intraosseous pressure,intravascular coagulation,second collision theory,etc.The purpose of this review is to summarize the etiology and pathogenesis of osteonecrosis of the femoral head.

[Objective]To investgate the expression of vascular endothelial growth factor in osteonecrosis of the femoral head during the repairing with biodegradable strontium-doped calcium polyphosphate in glucocorticoid-induced rabbits.[Method]Twenty mg/kg methylprednisolone was injected into right gluteus medius muscle at intervals of 24 hours for three times in 21 adult male Japanese white rabbits.Three rabbits were killed randomly at 2 weeks after methylpednisolone injection,both the femora and humeri were histologically examined for the presence of osteonecrosis. The remaining 18 animals with a total of 36 cylindrical 2.5?5 mm femoral head defects were created following the trapdoor procedure. Eighteen animals with femoral head bone defects were randomly divided into three groups. Group A:the defects filled with strontium-doped calcium polyphosphat,Group B:the defects filled with calcium polyphosphate and Group C:the defects filled with autologous cancellous bone alone. Roentgenographic and histological examinations were performed postoperatively. Finally,immunohistochemical analysis using monoclonal antibodies anti-VEGF was performed.[Result]No hip joint dislocation occurred. In Group A,the results of VEGF expression had a significantly difference from those in the other groups 12 weeks after operation. Most of the biodegradable strontium-doped calcium polyphosphate was resorbed and was largely replaced by newly formed trabecular bone at 12 weeks. While in Group B,a major part of defect were repaired. New formed trabecular bone in the defect was very thin. In Group C,morsellized cancellous bone was completely surrounded by fibrous and newly formed trabecular bone. [Conclusion]VEGF expression in the defect of osteonecrosis of the femoral head during the repairing with biodegradable strontium-doped calcium polyphosphate may play a role in stimulating vascular invasion and granulation tissue formation.This may be an important step toward facilitating the resorption in the osteonecrosis,thus impooring the repairing proceduce of femoral head defect.

Objective To retrospectively analyze the short-term clinical effects of the two-stage cementless total hip arthroplasty in the treatment of chronic infection after the internal fixation of the adult proximal femoral fracture.Methods From June 2006 to June 2011,9 patients who had suffered a chronic infection after an internal fixation of the proximal femoral fracture,including 8 males and 1 female,aged from 31 to 74 years (average,52.6 years),were treated with two-stage cementless total hip arthroplasty.There were 3 cases of femoral neck fracture,and 6 cases of intertrochanteric fracture.In the first stage,after surgical debridement and thorough removal of all the implants,an antibiotic-loaded cement spacer was implanted.All patients postoperatively underwent intravenous and oral antibiotics,and the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were tested.When the values of ESR and CRP become normal,the second stage operation using cementless components was performed.Results The presence of infection was confirmed by a positive culture of joint fluid obtained intraoperatively in two cases;one case was staphylococcus aureus and another one was staphylococcus epidermidis.The second stage arthroplasty was performed 6-14 months (average,9 months) after the first stage operation.All 9 patients were followed up for an average of 23.2 months (range,6 to 50 months).No recurrent infection,component loosening,bone osteolysis and cement spacer or component dislocation occurred.The Harris score improved from 74.6 (range,64 to 86) before the first stage operation to 90.9 (range,86 to 97) at the final follow-up.Conclusion The two-stage cementless total hip arthroplasty is an effective strategy for the treatment of chronic infection after the internal fixation of the adult proximal femoral fracture.

Objective To retrospectively analyze the diagnosis and treatment of the extra-articular inflammatory pseudotumor after well-fixed metal-polyethylene total hip arthroplasty (THA).Methods From March 2006 to June 2011,7 patients (7 hips) who presented with a progressive pain and/or swelling,discomfort in groin or upper thigh after metal-polyethylene THA were admitted to our hospital.There were 2 males and 5 females,with an average age of 48.8 years (range,32-65 years).All 7 patients were identified with a periprosthetic osteolysis at the acetabular and/or femoral components and a mass in the iliac fossa or the thigh; however,the components were all well-fixed.The masses were confirmed by CT scanning and/or ultrasound examination.The revision procedures were done through ilioinguinal approach and posterior-lateral approach,and the pseudotumors were excised and osteolytic lesions were debrided and packed tightly with morselized cancellous allograft.The liner and femoral head were also exchanged at the same time.Clinical and radiographic outcomes of revision THA were evaluated.Results All 7 patients were followed up for 3-42 months (average,30 months).At final follow-up,all hips were functioning well and the average Harris hip score was 92.4.All acetabular components remained radiographically well-fixed.All cavitary defects had complete radiographic incorporation of the bone grafts.There were no new pseudotumor or osteolytic lesions identified,and no revision of the components.Conclusion The presence of abdominal or pelvic pseudotumor in patient with a THA may be associated with polyethylene wear.Once the extra-articular pseudotumor and the periprosthetic osteolysis are identified,the surgical treatment,including pseudotumor excise,osteolytic lesion debride and bone defect grafting and bearing surface exchange,can achieve retention of well-fixed components.

Objective To study the early diagnosis and treatment of the blunt popliteal artery injury without fracture or dislocation of the knee. Methods From March 1984 to November 2002, 11 cases of blunt popliteal artery injury without fracture or dislocation of the knee were diagnosed as earlier as possible based on clinical analysis including injury condition, clinical examination and Doppler-Duplex ultrasonography and treated with early repair of the injured arteries, intraoperative or postoperative anticoagulation, immediate fasciotomy and thorough debridement of the ischemic and necrotic muscules and soft tissue. Results There was one with amputation and two with slight dysfunction of the lower extremity, as did not affect normal daily lives. One case had serious dysfunction of the lower extremity due to thrombosis at the injured popliteal artery after first operation and had to receive second operation so as to remove thrombus and repair the popliteal by autograft of the saphena magna vein. However, there left severe function disorder of the extremities. Conclusion A rational and prompt diagnosis and treatment for blunt popliteal artery injury without fracture or dislocation of the knee will decrease the adverse effect of ischemia and reduce overall morbidity.

Objective To evaluate the results of using focus clearance and morselized bone graft to treat a well-fixed socket osteolysis after total hip arthroplasty (THA) during cementless acetabular revisions.Methods From March 2006 to March 2009, 23 patients (23 hips) who had an acetabular revision hip arthroplasty of well-fixed socket for osteolysis were retrospectively reviewed, including 13 males and 10 females with an average age of 46.6 years (range, 39-54), and the mean interval from primary to revision THA was 5.5 years (range, 4.6-7.4). The preoperative Harris hip score was 74. The operative technique included debridement of soft tissues with removal of granulomata and packed tightly with morselized cancellous allograft through ilioinguinal approach, and exchanging the liner and femoral head through the posterior-lateral approach of the hip. Results The mean duration of follow-up after revision was 28 months (range, 8-38). At final follow-up, all hip were functioning well and the average Harris hip score was 93.8. Osteogenesis in bone graft were well-developed in 16 patients. Twelve bone grafts were completely incorporated into surrounding bone through creeping substitution. All acetabular components remain radiographically well-fixed and no loosening and shifting. There were no new osteolytic lesions, ectopic ossification, deep venous thrombosis, hip dislocation or infection during follow-up. Conclusion Our revision strategies included debridement and bone grafting, a revision of femoral heads and polyethylene liner and retention of the cups and femoral stems. The method can reduce the amount of the wear particle from polyethylene. The short-term outcome is excellent.

Objective To investigate the efficacy and safety of tranexamic acid on bleeding in rheumatoid arthritis (RA) patients undergoing total hip arthroplasty (THA). Methods A retrospective study was performed in 197 RA patients (Steinbrock?er III-IV) following primary unilateral THA from June 2012 to June 2014. The patients were divided to three groups based on the regimen of tranexamic acid:68 patients received a single intravenous dosage of 15 mg/kg tranexamic acid 20 min prior to opera?tion (single dose group);74 patients received an intravenous dosage of 15 mg/kg preoperatively and a second dosage of 10 mg/kg 3 hours postoperatively (repeated dose group);the other 55 patients didn't receive tranexamic acid (control group). The primary out?comes were total blood loss, transfusion rate, the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE). The sec?ondary outcomes were postoperative drainage, hemoglobin (Hb) drop on third day postoperatively and other wound related compli?cations. Results There was less total blood loss (816.80 ± 245.09 ml vs 975.15 ± 216.33 ml vs 1 295.68 ± 263.85 ml), drainage (221.60 ± 70.05 ml vs 337.20 ± 113.10 ml vs 479.74 ± 120.66 ml), transfusion requirement (5.41%vs 10.29%vs 25.45%) and Hb drop (2.71±0.74 g/dl vs 3.18±0.62 g/dl vs 3.83±0.70 g/dl) in experimental group when compared with control group. And the effect was better in repeated dose group, with less total blood loss (816.80 ± 245.09 ml), less transfusion requirement (5.41%) and less postoperative drainage (221.60±70.05 ml). No episode of DVT or PE occurred in either group. There were 8 wound complications in single dose group, 6 in repeated group, and 8 in control group, and there were no statistically difference. Conclusion Intrave?nous administration of tranexamic acid was effective and safe on decreasing blood loss and transfusion requirement in RA patients following THA. Compared with a single dosage of tranexamic acid preoperatively, a second dosage of tranexamic acid 3 hours post?operatively was recommended.

Objective To compare the kinematics of the knee joint of normal Chinese people and people after fixed-bearing posterior stabilized total knee arthroplasty while doing weight-bearing deep knee-bending using fluoroscopy analysis.Methods From June to December 2010,ten volunteers and ten patients with fixed-bearing posterior stabilized total knee arthroplasty (TKA) were required to perform weight-bearing deep knee-bending activity under surveillance of roentgenization,motion between femur and tibia was analyzed with interval of 15° according to two-to three-dimensional (2D-3D) registration technique.Results During weight-bearing deep knee-bending,the average weight-bearing maximal flexion was 136° in the normal group,which was significantly higher than the 125° in the TKA group.All 10 normal knees present posterior translation of femoral condyle during deep knee-bending,posterior translation of the lateral condyle was greater than medial condyle,thereby creating a medial pivot type of axial rotational pattern in which the tibia internally rotates relative to the femur as flexion increased.The average amount of posterior femoral translation of the medial condyle was 7.3±1.2 mm,whereas the lateral condyle translated posteriorly 19.3±3.1 mm.All knees experienced tibia rotated internally during progressive flexion,and the average amount of axial rotation for the ten subjects from 0° to 135° was 23.8±3.4°.From extension to maximal flexion,the average amount of posterior translation of medial condyle was 1.4±0.6 rmm,whereas the lateral condyle translated 6.4±1.7 mm in the posterior direction in the fixed-bearing posterior-stabilized TKA.The average amount of tibial internal rotation was 8.5°±3.4°.Conclusion In normal Chinese people,during knee flexion activities the lateral condyle experiences significantly more amount of posterior translation than the medial condyle,leading to the tibia present medial pivot internal rotation relative to the femur,and the PFC-Sigrna fixed-bearing posterior stabilized designs has the similar kinematics with normal knee,but the posterior condylar translation and tibial axial rotation are much less than the normal.

Objective To explore the anatomical morphology of femoral trochlear groove and the difference between normal males and females.Methods Eighty healthy volunteers were recruited,including 42 males and 38 females with an average age of 36.2 years (range,21-55 years).All the volunteers without knee unstabilization,pain and wound.CT scan of right femurs were performed and 3-D model were reconstructed.The anatomical parameters of right femoral trochlear groove were measured,which included transepicondylar axis,medial and lateral length of trochlear groove,medial and lateral condylar height,sulcus angle,depth of trochlear groove,transcondylar axis,anterior femoral condylar angle,trochlear groove position,and then compared the morphologic difference of trochlear groove between males and females.Results The average width of transepicondylar axis was 79.21±3.80 mm for males and 70.73±2.91 mm for females (t=-53.40,P=0.00).The minimum sulcus angle was acquired at 45° flexion for males and 42° flexion for females.It was 133.92°±4.76° for males and 132.71°±4.36° for females.The maximum length of transepicondylar axis was acquired at 87° flexion for males and 90° flexion for females.It was 42.36±3.48 mm for males and 39.03 ±3.36 mm for females.The anterior femoral condylar angle decreased with the increasing flexion angle of knee (P＞0.05).The position of the trochlear groove moved laterally with the increasing flexion angle of knee (P＞0.05).Conclusion There is no significant difference between male and female in the geometry of femoral trochlear groove,however there is a significant difference in sizes.Therefore,during design the knee prosthesis,close approximation of size is essential,while gender differences in morphology need not be considered a factor.