Targeting macrophagic SHP2 for ameliorating osteoarthritis via TLR signaling

Osteoarthritis (OA), in which M1 macrophage polarization in the synovium exacerbates disease progression, is a major cause of cartilage degeneration and functional disabilities. Therapeutic strategies of OA designed to interfere with the polarization of macrophages have rarely been reported. Here, we report that SHP099, as an allosteric inhibitor of src-homology 2-containing protein tyrosine phosphatase 2 (SHP2), attenuated osteoarthritis progression by inhibiting M1 macrophage polarization. We demonstrated that M1 macrophage polarization was accompanied by the overexpression of SHP2 in the synovial tissues of OA patients and OA model mice. Compared to wild-type (WT) mice, myeloid lineage conditional Shp2 knockout (cKO) mice showed decreased M1 macrophage polarization and attenuated severity of synovitis, an elevated expression of cartilage phenotype protein collagen II (COL2), and a decreased expression of cartilage degradation markers collagen X (COL10) and matrix metalloproteinase 3 (MMP3) in OA cartilage. Further mechanistic analysis showed thatSHP099 inhibited lipopolysaccharide (LPS)-induced Toll-like receptor (TLR) signaling mediated by nuclear factor kappa B (NF-κB) and PI3K-AKT signaling. Moreover, intra-articular injection of SHP099 also significantly attenuated OA progression, including joint synovitis and cartilage damage. These results indicated that allosteric inhibition of SHP2 might be a promising therapeutic strategy for the treatment of OA.

The incidence and risk factors of preoperative deep vein thrombosis in non-fracure patients awaiting for total joint arthroplasty / 中华骨科杂志

Objective:To explore the incidence and risk factors of preoperative deep vein thrombosis (DVT) of elective total joint arthroplasty (TJA).Methods:Data of 500 patients before TJA from March 2015 to August 2016 who underwent ultrasound surveillance were retrospectively analyzed. All patients were divided into DVT group and non-DVT group according to results of ultrasound. Parameters including demographic data, basic medical history, and surgical information and laboratory indexes were collected. Risk factors were assessed via univariate, multivariate and logistic regression analysis.Results:Preoperative DVT was detected in 23 cases (4.6%, 23/500), all of which occurred in the intermuscular vein with no symptom, and among them there were 16 cases (5.6%, 16/285) before total knee arthroplasty and 7 cases (3.3%, 7/215) before total hip arthroplasty. Univariate analysis showed that age ( t=2.266, P=0.024), female patients ( χ2=4.028, P=0.045), history of hypertension ( χ2=7.907, P=0.005), D-dimer ≥0.5 μg/ml ( χ2=13.171, P < 0.001) were significantly higher than those in non-DVT group, and the differences were statistically significant. Multivariate analysis showed that D-dimer ≥0.5 μg/ml [ OR=6.655, 95% CI (1.929, 22.960), P=0.003] and history of hypertension [ OR=2.715, 95% CI (1.017, 7.250), P=0.046] were independent risk factors for preoperative DVT. Among them, the thrombus of 14 cases located in the operation side, 6 cases in non-operation side, and 3 cases in bilateral sides. Postoperative ultrasound showed that newly DVT occurred in 9 patients of whom 5 cases located in the contralateral muscular veins and 4 cases in the nearby muscular veins. After discharge, 22 patients (95.7%) with preoperative DVT were further evaluated by ultrasound. The average follow-up time was 3.0 months (range from 6 weeks to 9 months). The results showed that thrombus of 7 cases were completely dissolved, 13 cases were partially dissolved, and 2 cases remained unchanged. Thrombus extensions to proximal veins or symptomatic PE were not found. Conclusion:The incidence of preoperative DVT in patients with elective joint replacement was about 4.6%, among which D-dimer ≥0.5 μg/ml and history of hypertension were the risk factors for preoperative thrombosis.

Comparison of notch width indexes between tibial intercondylar eminence avulsion fracture and anterior cruciate ligament injury / 中华创伤骨科杂志

Objective To find out if there is any difference in intercondylar fossa width and notch width index (NWI) between tibial intercondylar eminence avulsion fracture and anterior cruciate ligament (ACL) injury.Methods A retrospective study was conducted of the patients who had sought medical attention at Department of Sports Medicine and Adult Reconstructive Surgery,Drum Tower Hospital from June 2014 to May 2018.There were 10 patients with tibial intercondylar eminence avulsion fracture (4 males and 6 females with an average age of 32.7 ± 9.2 years),13 patients with ACL injury (8 males and 5 females with an average age of 31.8 ± 10.9 years) and 22 patients with simple meniscus injury as controls (13 males and 9 females with an average age of 30.9 ± 10.6 years).They all had MRI examination of the knee before surgery.The width of intercondylar fossa and the width and height of bilateral femoral condyles were measured on high resolution images of MRI axial view.NWI was calculated.The 3 groups were compared in intercondylar fossa width and NWI.Results The 3 groups of patients were comparable because there were no significant differences in gender,age,height,weight or BMI between them (P ＞ 0.05).The intercondylar fossa width in the ACL injury group (17.4 ± 3.5 mm) was significantly smaller than that in the avulsion fracture group (20.8 ± 1.1 mm) or in the control group (20.2 ±2.6 mm) (P ＜ 0.05),but no significant difference was detected between the avulsion fracture group and the control group (P ＞ 0.05).NWI in the avulsion fracture group (0.301 ±0.011) was similar to that in the control group (0.280 ±0.039) (P ＞ 0.05) but significantly higher than that in the ACL injury group (0.25 ± 0.05) (P ＜ 0.05).NWI in the ACL injury group was significantly lower than that in the control group (P ＜ 0.05).Conclusions Intercondylar notch stenosis may be a risk factor for ACL injury but may not be associated with tibial intercondylar eminence avulsion fracture.The difference in pathogenesis between tibial intercondylar eminence avulsion fracture and ACL injury may be associated with their difference in NWI.

The feasibility of management with acute proximal deep vein thrombosis without insertion of inferior vena cava filter before hip arthroplasty / 中华骨科杂志

Objective To evaluate the feasibility of anticoagulant therapy for acute proximal deep vein thrombosis without inferior vena cava filter placement for femoral neck patients before hip arthroplasty.Methods From January 2013 to August 2017,9 femoral neck fractures patients with acute proximal deep vein thrombosis before hip arthroplasty were enrolled into this study.There were 3 men and 6 women.The average age was 76.44±5.39 years old (range,69 to 83 years old).The average injured time before admission was 4.00±4.06 days.All patients received anticoagulant therapy without placement of inferior vena cava filter before hip arthroplasty.Four patients received Rivaroxaban 10mg,two times per day,while two patients received Enoxaparin 0.4 ml,two times per day;3 cases received Batroxobin 0.5 ml,every other day combined with Rivaroxaban 10 mg one time per day or Enoxaparin 0.4 ml,one time per day.The size of thrombus before and after treatment,changes of coagulation markers,the outcome of thrombosis before surgery,during surgery,postoperatively and during follow-up,the related complications were recorded.Results The diagnosis time for proximal DVT was 3.89±3.01 days after admission.8 patients showed proximal DVT combined with distal thrombus and 1 patient showed isolated proximal DVT.The average length of proximal thrombus was 10.78±6.10 cm (range,4.0-20.0 cm).The mean duration of treatment was 14.22±7.03 days.The results showed 5 proximal DVTs have complete disappeared,3 cases significantly improved,and 1 case had no change but showed stable.After treatment,the length of the proximal thrombus was significantly decreased (10.77±6.10 cm vs.4.39±6.50 cm),there were statistically significant between two groups (t=3.429,P=0.009);D-dimer was significantly lower after treatment (10.47±4.87 μg/ml vs.2.59± 1.60 μg/ml) with statistical difference (t=4.970,P=O.O01).However,no statistical significance was found in other coagulation parameters such as plasma prothrombin time,the international normalized ratio,activated partial thromboplastin time,thrombin time,fibrinogen.Incision exudate occurred in one patient and anticoagulant therapy was paused,however,two days later,DVT recurred and then the patient received continuous therapy with drug anticoagulation.The average time for postoperative follow-up was 8.3±7.6 months.At the latest follow-up,4 cases had thoroughly recovered with the thrombi fully resolved;4 cases had significantly improved including three thrombi partly locating in the muscular veins and one partly locating in the infra-popliteal vein.One case became more severe after discharge and received continuous anticoagulant therapy.No death,symptomatic pulmonary embolism,bleeding and other adverse events occurred.Conclusion Inferior vena cava filter placement for femoral neck fracture patients with acute proximal venous thrombosis before hip arthroplasty may not be potent.Anticoagulant therapy which make the proximal thrombus completely dissolved or stabilized before surgery may be effective.

The characteristics of proximal deep vein thrombosis after total knee and hip arthroplasty / 中华骨科杂志

Objective To analyze the characteristics of proximal deep vein thrombosis (DVT) after total joint arthroplasty.Methods 40 cases of proximal DVT were collected from May 2007 to October 2016 which were all diagnosed by lower limb venography or sonography.There were 9 males and 31 females aged from 38 to 86 years,average 67 years,and body mass index was from 16.94 to 31.25kg/m2,with an average of 24.3 kg/m2.29 cases of THA patients and 11 cases of TKA patients.The anatomical distribution,size,radiological performance,local physical findings were recorded and multivariable analysis was performed to evaluate the relationship between distribution of proximal DVT and related parameters including age,gender (male/female),side of leg(left/right),surgery type(knee and hip),preoperative diagnosis(femoral neck fracture/other disease),time of diagnosis with DVT (during hospitalization/after discharge).Results Among 40 proximal DVT cases,31 cases diagnosed by phlebography and 9 cases were diagnosed by ultrasound.2 cases were isolated proximal DVT while 38 cases connected with distal DVTs.9 cases of blood clots in the proximal and distal thrombosis connected discontinuously.There was no isolated proximal DVT in TKA group and 10 cases (90.9％) of blood clots in the proximal and distal thrombosis connected continuously while there were 2 cases (6.9％) isolated proximal DVTs in THA group and 21 (77.8％) of blood clots in the proximal and distal thrombosis connected discontinuously,and there was no statistic significant difference between the two groups.The average length of proximal was 8.85±9.3 1cm (range from 2-35cm) with 5.0±2.05 cm in TKA group and 10.31 ± 10.55 cmin THA group.A significant difference was found between the 2 groups (P=0.014).13 cases located in femoral veins and upper venous region which were all from THA group.There was a significant difference in the distribution between surgery type and preoperative diagnosis.However,there was no significant difference between other potential factors and distribution of proximal DVT.25 cases accepted the evaluation of symptom of DVT before scanning.However,no significant difference were found in edema,VAS score,Homans sign,Neuof sign between 9 TKA and 16 THA cases.Conclusion Proximal DVTs after knee and hip arthroplasty are more preferred to connect with distal DVT continuously.Surgery type and preoperative diagnosis have a significant effect on the distribution of proximal DVT.Proximal DVTs in THA and patients with preoperative femoral neck fracture could be more easily involving femoral veins and upper parts.

Seasonal variations in the incidence of deep vein thrombosis following total knee or hip arthroplasty / 中华骨科杂志

Objective To explore the difference in the incidence of deep vein thrombosis (DVT) following total knee arthroplasty (TKA) or total hip arthroplasty (THA) between different seasons.Methods The present retrospective study examined 2 363 patients undergoing TKA or THA from August 2008 to February 2016.There were 653 male and 1 710 female with the average age of 64.44±13.03 years old (17-91 years old),including 954 patients in TKA and 1 409 in THA.All of the patients received anticoagulant drugs and were compressed with a pressure pump starting on the first postoperative night.Routine venography of the bilateral lower limbs was performed at 3-5 days after the operation.The incidence of DVT in different seasons and different age groups (≥65 years old and ＜65 years old) were counted.Results The present study suggested that the probabilities of DVT after arthroplasty in spring,summer,fall and winter were 15.85％ (116/732),14.92％ (71/476),17.88％ (108/604),22.50％ (124/551) respectively with significantly difference (P＜0.05).The incidence of DVT in winter was higher than that in spring and summer (P＜ 0.017).The probabilities of DVT after TKA in spring,summer,fall and winter were 19.09％ (59/309),15.67％ (37/236),18.11％ (44/243),27.71％ (46/166) respectively with significantly difference (P＜0.05).The incidence of DVT in winter was higher than that in summer (P＜0.017).The probabilities of DVT after THA in spring,summer,fall and winter were 13.48％ (57/423),14.17％ (34/240),17.73％ (64/361),20.26％ (78/385) respectively with significantly difference (P＜0.05),and that in winter was higher than in spring (P＜0.017).The symptomatic DVT after arthroplasty in spring,summer,fall and winter were 3.55％ (26/732),3.78％ (18/476),4.97％ (30/604),6.90％ (38/551) with significantly difference in different seasons (P＜0.05),and that in winter was higher than in spring (P＜0.017).The symptomatic DVT after TKA in spring,summer,fall and winter were 3.88％ (12/309),4.24％ (10/236),4.94％ (12/243),9.64％ (16/166) with significantly difference in different seasons (P＜0.05).The symptomatic DVT in winter was higher than that in spring (P＜0.017).The symptomatic DVT after THA in spring,summer,fall and winter were 3.31％ (14/423),3.33％ (8/240),4.99％ (18/361),5.71％ (22/385) respectively (P＞0.05).The probability of DVT following arthroplasty in older patients (age≥65 years old) in spring,summer,fall and winter were 18.49％ (76/411),16.61％ (45/271),22.07％ (81/367),28.05％ (99/353) with significantly difference among the groups (P＜0.05),while symptomatic DVT in older patients (≥65 years old) in spring,summer,fall and winter were 4.38％ (18/411),4.43％ (12/271),5.72％ (21/367),8.78％ (31/353) respectively with significantly difference (P＜0.05).The probability of DVT in four seasons were 12.46％ (40/321),12.68％ (26/205),11.39％ (27/237),12.63％ (25/198) in younger patients (＜65 years old).However,the difference was not detected among different seasons (P＞0.05).The probability of symptomatic DVT in four seasons were 2.49％ (8/321),2.93％ (6/205),3.80％ (9/237),3.54％ (7/198) in younger patients (＜65 years old) without significant difference (P＞0.05).Conclusion Seasonal variations could place an important effect on the incidence of DVT following TKA or THA,especially for the old patients with age ≥65 years.

A Practical Method for Acetabulum Component Assembling in Total Hip Arthroplasty with Lateral Position / 中国运动医学杂志

Objective To get a controllable acetabulum component inclination angle during the total hip arthroplasty(THA) with the lateral position,a new method using a self-made instrument was introduced.Methods Totally 80 consecutive patients undergoing THA at the lateral position were enrolled.Forty acetabular components were assembled using a new method with a self-made instrument referring to the 42 degrees' angle drawn on the wall(group A),while another 40 acetabular cups were implanted free-handedly(group B).The postoperative inclination angle was evaluated on the anterior-posterior pelvic radiographs.Results The average inclination angle was 43.3° ± 3.7°(34.7°～49.1°) in group A and 40.3 ± 4.5o(32.8°～50.7°) in group B.Moreover,40/40 of group A and 38/40 of group B were in the Lewinnek's inclination safe zone(P＞0.05),without significant differences between the two groups.Conclusion It is practical and reliable to decide the acetabular component orientation using the lateral position instrument and reference angle on the wall.

Primary usage of a new designed extramedullary femoral alignment system in total knee arthroplasty / 中华骨科杂志

Objective To investigate the outcome of a new designed extramedullary femoral alignment system and to compare with conventional intramedullary system in clinical results.Methods Twenty consecutive patients (3 males and 17females with an average age of 70.1 (range,52-82 years old) with osteoarthritis (OA) or rheumatoid arthritis (RA) who were treated with the extramedullary method between January 2015 to August 2015 and 20 consecutive patients (5 males and 15 females with an average age of 65.9 (range,52-87 years old) with OA or RA treated with conventional intramedullary method between April 2015 to September 2015 were studied.In extramedullary group,CT scan was used to evaluate the relation between the hip (femoral head) center and anterior superior iliac spine preoperatively.During the total knee arthroplasty,the hip joint center was defined according to the anterior superior iliac spine (ASIS).Knee joint center was defined as the center of the line connecting medial and lateral epicondyle.The terminal femoral bone cut plane was defined as the line between femoral and knee center.In intramedullary group,the traditional intramedullary method was adopted.The coronal and sagittal alignment,blood loss and drainage at one week postoperatively and the range of motion at one week,6 weeks and 3 months were evaluated.Results There was no significant difference in age,hip-knee-ankle (HKA) angle,the Hospital for Special Surgery (HSS) Knee Score,BMI,operation time within the two groups.Blood loss and drainage in extramedullary group (121 ±64 ml and 181±149 ml) was significantly less than that in intramedullary group (177±47 ml and 292±156 ml).There was no significant difference in coronal alignment of the femoral prosthesis within the two groups (89.8°±2.1° v.s.89.8°±2.2°,P＞0.05).However,the two groups had significant difference in sagittal alignment (-0.8°±2.2° v.s.2.5°±2.1 °,P＜0.05).The alignment of extramedullary group had much more tendency in flexion degree.No difference was found in range of motion at 1 week,6 weeks and 3 months postoperatively (103.8°±7.8° v.s.102.5°±7.2°,108.5°±8.0° v.s.108.3°±7.4°,117.0°±7.1° v.s.114.5°±8.1°,P＞0.05).Conclusion The present designed extramedullary system is practical in total knee arthroplasty and has more accuracy in sagittal plane.The patients treated with extramedullary system have less blood loss and drainage and have similar range of motion in early stage after operation when compared with the intramedullary method.

The role of postoperative levels of neutrophil extracellular traps in deep vein thrombosis after total knee arthroplasty / 中华骨科杂志

Objective To investigate the role of circulating neutrophil extracellular trap (NET) levels in the postoperative formation of deep vein thrombosis (DVT) in patients undergoing total knee arthroplasty (TKA). Methods Circulating NET levels were measured preoperatively and on postoperative days 1, 3, and 7 in 30 patients diagnosed with DVT by venography after TKA and 30 controls from May 2014 to July 2015. Results In patients with DVT, the mean circulating NET levels were significantly higher on postoperative days 1 and 3 compared with those in the non?DVT group (postoperative day 1, 1.598 ± 0.067 vs. 1.212 ± 0.037, t=7.514, P=0.000;postoperative day 3, 1.305±0.044 vs. 1.167±0.032, t=2.675, P=0.015). ROC curve analysis revealed the inferior sensitivity and specificity of NET levels on postoperative day 3 compared with postoperative day 1. Area under the curve (AUC) postoperative day 1 was 0.828 (95%CI:0.722, 0.933, P=0.000);AUC postoperative day 3 was 0.677 (95%CI:0.541, 0.814, P=0.018). The cutoff point for NET levels on postoperative day 1 was 1.294, with a sensitivity of 80%, a specificity of 80%, a posi?tive predictive value of 80%, and a negative predictive value of 80%. After Logistic regression, the NET level on postoperative day 1 was considered an independent predictor of DVT (OR:24.08, 95%CI:4.94, 117.28, P=0.000). Conclusion High circulating NET levels are associated with DVT in patients who undergo TKA. NETs may serve as a potential biological marker to delineate patients undergoing TKA who are most at risk for DVT.

Diagnostic value of plasma D-dimer and fibrinogen in acute lower extremity deep vein thrombosis after artificial joint replacement / 中华骨科杂志

Objective To evaluate diagnostic value of plasma D-dimer (D-D),fibrinogen (Fg) and Ddimer/fibrinogen (D/F) ratio in acute lower extremity deep vein thrombosis (DVT) after artificial joint replacement.Methods From August 2009 to December 2011,273 patients who had undergone total hip arthroplasty (THA) or total knee arthroplasty (TKA) underwent venography of lower extremity deep vein at 35 days postoperatively.According to results of angiography,all patients were divided into DVT group including 66 patients (15 males and 51 females,median age 66 years) and non-DVT group including 207 patients (70 males and 137 females,median age 63 years).Plasma levels of D-D and Fg were measured by immunoturbidimetry and solidification methods respectively preoperatively and at 3-5 days postoperatively.The differences of plasma levels of D-D and Fg and D/F ratio between the two groups were analyzed with statistical method.Furthermore,diagnostic value of postoperative plasma D-D and D/F ratio in acute DVT was assessed using a receiver operating characteristic (ROC) curve.Results There was no statistical significance in preoperative plasma levels of D-D and Fg,and postoperative plasma levels of Fg between two groups.However,the postoperative plasma levels of D-D and D/F ratio were higher in the DVT group than those in the nonDVT group,and there was significant difference between two groups.In addition,the ROC curve analysis showed that the area under curve of postoperative plasma D-D and D/F ratio was 0.688 and 0.684,respectively,but this difference did not reach statistical significance.Conclusion Plasma Fg may be meaningless for the diagnosis of acute DVT after artificial joint replacement.Although plasma D-D and D/F ratio may be useful for diagnosing acute DVT,the diagnostic accuracy is low.

Femoral head-neck ratio in patients with Cam-type femoroacetabular impingement and healthy adults and its impact on surgical strategy / 中华骨科杂志

Objective To explore the difference of the femoral head-neck ratio (FHNR) in patients with Cam-type femoroacetabular impingement (FAI) and healthy adults and its impact on surgical strategy.Methods We measured the FHNR using method described by Doherty.468 healthy adults without hip symptoms acted as controls in the study,including 313 males and 155 females,with the mean age of 42.4years (range,17-82 years).There were 17 patients (24 hips) in the Cam-type FAI group.The maximum diameter of the femoral head and the minimum vertical diameter of femoral neck on both sides were measured by Digimizer software on the standard anteroposterior pelvis film.The ratio of femoral head to femoral neck was calculated and was compared.The surgery was performed in 7 cases (8 hips) with FAI.The Harris score and internal rotation angle was also compared.Results The FHNR of control group and Cam-type FAI group was 1.48±0.09(1.33-1.69) and 1.30±0.13 (1.01-1.46) separately (P＜0.01).The volume of osteophyte removed during operation was related with the FHNR.The average Harris score had improved from 63.4±8.2(52-76) preoperatively to 89.2±3.5(84-95) postoperatively.The average internal rotation angle had improved from 2.5°±2.7°(0°-5°) preoperatively to 12.5±3.8°(5°-15°) postoperatively.Conclusion FHNR measurement is useful for the diagnosis and surgical treatment of Cam-type FAI.

The measurement of femoral head-neck ratio and its clinical significance in Chinese / 中华骨科杂志

Objective To measure the femoral head-neck ratio among Chinese adults in Nanjing to explore its clinical significance. Methods 468 Chinese without hip symptoms were chosen randomly. There were 313 males and 155 females. 13 cases were less than 20 years old, 88 cases were from 21 to 30 years old, 123 cases were from 31 to 40 years old, 104 cases were from 41 to 50 years old, 102 cases were from 51 to 60 years old, 24 cases were from 61 to 70 years old, 14 cases were more than 71 years old. The mean age was 42.4 years old (ranged from 17 to 82 years old). The maximum diameter of the femoral head and the minimum vertical diameter of femoral neck length on both sides were measured by Digimizer software in the standard anteroposterior pelvis film. The femoral head-neck ratio (FHNR) was calculated and compared with that of the western. Results The normal FHNR of Chinese in Nanjing was 1.48 ± 0.09 (1.33-1.69). FHNR was 1.46±0.09 in Chinese aged less than 20 years old. It was 1.48±0.09 in Chinese aged from 21 to 30 years, and 1.47±0.10 in those aged 31-40 years, 1.46±0.09 in 41-50 years, 1.49±0.10 in 51-60 years,1.48±0.08 in 61-70 years, 1.49±0.10 in those more than 71 years. There was no difference between male and female, the left and right side or the different age groups. There was no difference between the western and Chinese in Nanjing. Conclusion FHNR measurement has not variation with regard to sex, age and side. It may be useful to understand some kind of the hip diseases.

Articulating spacer in the two-stage revision for severe infected knee arthroplasty / 中华骨科杂志

Objective To investigate the efficiency and safety of articulating spacer for severe infected knee arthroplasty in patients with medical comorbidities and local sinus tracts. Methods Ten consecutive patients with medical comorbidities (rheumatoid arthritis, diabetes mellitus, etc) or local sinus tracts,who were complicated with late infected TKA, were included in the study. All the patients underwent twostage revision using articulating spacers. All of the patients were debridement thoroughly and followed by implantation of an antibiotic-loaded cement articulated spacer. Two-stage revisions were not followed untill the infection were controlled. The hospital for special surgery (HSS) knee scoring system and range of motion were used to evaluate the outcomes. Results One patient underwent knee fusion because the infection was not controlled after first-stage surgery. The other 9 patients had no evidence of infection. The mean follow-up was 50 months (range, 24-90 months), no recurrent infection developed for these 9 patients. The mean modified HSS score had improved from 48 points (range, 32-63) before the resection surgery to 79 points (range,62-91) at the end of the spacer period. At the latest follow-up, the modified HSS score averaged 89 points (range, 74-95). The good and excellent rate was 0, 80% and 100%, respectively. The average range of motion had increased from 13°-70° preoperatively to 8°-93° prior to the revision. And at the latest follow-up, the range of motion averaged 3° to 110°. Conclusion The delayed two-stage revision using an articulating spacer is effective in the treatment of chronically infected TKA characterized by simple, good reproducible, high rate of infection control, better joint function after surgeries

Association of genetic and mechanical factors with age of onset of knee osteoarthritis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze the relationship of genetic and mechanical factors with age of onset of knee osteoarthritis (OA).</p><p><b>METHODS</b>Cross-sectional and longitudinal studies were conducted in 863 patients with knee OA and 999 age-matched controls from Chinese Han population with complete clinical data. Single nucleotide polymorphisms of + 104T/C in rs143383 of the growth differentiation factor 5 (GDF5) gene and the aspartic acid repeat polymorphism of the asporin gene ASPN were genotyped by taqman probe and polyacrylamide gel electrophoresis respectively.</p><p><b>RESULTS</b>Body mass index (BMI) in subjects with knee OA was significantly higher than that in controls (P< 0.01). Obesity (BMI≥ 25) was a high risk factor for knee OA (P< 0.01). Regression analysis showed that there was a certain correlation between the BMI and age of onset of the knee OA (Pearson= 0.15, P< 0.01). To analyze the BMI distribution, the two groups were subgrouped by age with 5-year interval. The BMI in early-onset patients was lower than that in the late-onset patients (F= 2.497, P= 0.011). However, there was no significant difference in the control subgroups. Frequencies of the GDF5 and ASPN alleles distributed differently between the early- and late-onset patients (P< 0.05).</p><p><b>CONCLUSION</b>Genetic factors play an important role in knee osteoarthritis of early-onset patients, whereas mechanical factor play an important part in knee osteoarthritis of late-onset patients.</p>

Progress in researches on the molecular genetics of developmental dysplasia of the hip / 中华医学遗传学杂志

Epidemiological studies have confirmed that genetic factors play an important role in the incidence of developmental dysplasia of the hip (DDH). Previous studies showed that genetic factors accounted for a major part (about 67.88%), the remaining part was due to the environmental factors. At present, great progress has been made in the researches of the diagnosis and treatment of DDH, but there is no clear conclusion in the genetic etiology. This article reviews the latest studies of candidate genes and their mapping.