Loss of the posteromedial support: a risk factor for implant failure after fixation of AO 31-A2 intertrochanteric fractures / 中华医学杂志(英文版)

BACKGROUND@#The purpose of this study was to analyze cases of AO31-A2 intertrochanteric fractures (ITFs) and to identify the relationship between the loss of the posteromedial support and implant failure.@*METHODS@#Three hundred ninety-four patients who underwent operative treatment for ITF from January 2003 to December 2017 were enrolled. Focusing on posteromedial support, the A2 ITFs were divided into two groups, namely, those with (Group A, n = 153) or without (Group B, n = 241) posteromedial support post-operatively, and the failure rates were compared. Based on the final outcomes (failed or not), we allocated all of the patients into two groups: failed (Group C, n = 66) and normal (Group D, n = 328). We separately analyzed each dataset to identify the factors that exhibited statistically significant differences between the groups. In addition, a logistic regression was conducted to identify whether the loss of posteromedial support of A2 ITFs was an independent risk factor for fixation failure. The basic factors were age, sex, American Society of Anesthesiologists (ASA) score, side of affected limb, fixation method (intramedullary or extramedullary), time from injury to operation, blood loss, operative time and length of stay.@*RESULTS@#The failure rate of group B (58, 24.07%) was significantly higher than that of group A (8, 5.23%) (χ = 23.814, P < 0.001). Regarding Groups C and D, the comparisons of the fixation method (P = 0.005), operative time (P = 0.001), blood loss (P = 0.002) and length of stay (P = 0.033) showed that the differences were significant. The logistic regression revealed that the loss of posteromedial support was an independent risk factor for implant failure (OR = 5.986, 95% CI: 2.667-13.432) (P < 0.001).@*CONCLUSIONS@#For AO31-A2 ITFs, the loss of posteromedial support was an independent risk factor for fixation failure. Therefore, posteromedial wall reconstruction might be necessary for the effective treatment of A2 fractures that lose posteromedial support.

Risk factors of recurrent kyphosis in thoracolumbar burst fracture patients treated by short segmental pedicle screw fixation / 北京大学学报(医学版)

OBJECTIVE@#To analyze the risk factors of recurrent kyphosis after removal of short segmental pedicle screw fixation in patients with thoracolumbar burst fractures.@*METHODS@#Retrospective analysis was conducted of 144 cases of thoracolumbar burst fractures without neurological impairment treated in Peking University Third Hospital from January 2010 to December 2017. There were 74 males and 70 females, with an average age of (39.1±13.2) years. The distribution of the injured vertebrae was T12: 42, L1: 72 and L2: 30, with fracture types of A3: 90, B1: 25 and B2: 29. The patients were divided into two groups: Recurrent kyphosis group (n=92) and non-recurrent kyphosis group (n=52). SPSS 26.0 software was used for univariate analysis and Logistic regression analysis.@*RESULTS@#The average follow-up time was 28 (20-113) months. The imaging indexes of pre-operation, 3 days post-operation, 12 months post-operation and the last follow-up were measured and compared. Anterior vertebral body height, segmental kyphosis, vertebral wadge angle and Gardner deformity were significantly improved after operation (P < 0.05), and there were some degrees of loss in the 1-year follow-up; anterior vertebral body height and vertebral wadge angle were no longer changed after the removal of the screws; however, segmental kyphosis and Gardner deformity were still aggravated after the removal of the screws (P < 0.05). There were some degrees of collapse of the height of the upper and lower discs during the follow-up. Univariate analysis showed that there were statistically significant differences (P < 0.05) between the two groups in gender, age (36.9 years vs. 43.0 years), upper disc injury, CT value (174 vs. 160), segmental kyphosis (16.6° vs. 13.3°), vertebral wadge angle (16.7° vs. 13.6°), Gardner deformity (19.1° vs. 15.2°) and ratio of anterior vertebral body height (0.65 vs. 0.71). Logistic regression analysis showed that male (OR: 2.88, 95%CI: 1.196-6.933), upper disc injury (OR: 2.962, 95%CI: 1.062-8.258) and injured vertebral wedge angle were risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture (P < 0.05).@*CONCLUSION@#The patients with thoracolumbar burst fracture can obtain satisfactory effect immediately after posterior short segmental pedicle screw fixation, however, there may be some degree of loss during the follow-up. Male, upper disc injury and injured vertebral wedge angle are the risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture.

Analysis of risk factors for necrosis of femoral head after internal fixation surgery in young and mid-aged patients with femoral neck fracture / 北京大学学报(医学版)

OBJECTIVE@#To retrospectively analyze the risk factors of avascular necrosis of femoral head (ANFH) after internal fixation in young and mid-aged adults.@*METHODS@#From January 2007 to December 2017, femoral neck fracture patients (18-60 years old) treated by reduction and internal fixation were retrospectively studied in Peking University Third Hospital. We recorded their gender, age, body mass index (BMI), American Society of Anesthesiology (ASA) grade, reason of injury, fracture side, interval between injury and surgery, location of fracture line, Garden classification, Pauwels classification, reduction method (open or closed), internal fixation and reduction quality. The diagnosis of ANFH was confirmed based on X-ray and MRI images during the follow-up. The internal fixation method included cannulated compression screw (CCS) or dynamic hip screw (DHS, with or without anti-rotation screw). χ2 test and Logistic regression analysis were used to analyze the relationship between the various factors and postoperative ANFH.@*RESULTS@#A total of 113 patients were included in this study, including 63 males and 50 females with an average age of (43.17 ± 12.34) years. They were followed up by (25.08 ± 16.17) months. ASA grade included grade I (21 cases), grade II (55 cases) and grade III (37 cases). The reasons of injury included low-energy trauma (76 cases) and high-energy (37 cases). The fracture line included subcapital type (37 cases), transverse type (74 cases) and basal type (2 cases). Garden classification included type I (3 cases), type II (46 cases), type III (39 cases) and type IV (25 cases). Pauwels classification included type I (21 cases), type II (55 cases) and type III (37 cases). Interval between injury and surgery was (3.88 ± 3.66) days, 108 patients and 5 patients performed closed and open reduction respectively. 63 patients performed CCS, and 50 patients performed DHS. The reduction quality included grade A (91 cases), grade B (18 cases) and grade C (4 cases). 18 patients developed ANFH after surgery, the incidence rate was 15.93% (18/113). The result of χ2 test showed the reason of injury (OR=0.19, P < 0.01), Garden classification (OR=0.13, P < 0.01), Pauwels classification (OR=0.12, P = 0.02), internal fixation method (OR=3.29, P = 0.04) and reduction quality (OR=0.33, P < 0.01) were significantly associated with ANFH. These five factors were further included into the Logistic regression analysis, and its results showed that the reason of injury (OR=4.11, P = 0.03) and Garden classification (OR=4.85, P = 0.04) were statistically significant.@*CONCLUSION@#The reason of injury, Garden classification, Pauwels classification, internal fixation and reduction quality may increase the risk of ANFH after surgery, and the reason of injury and Garden classification were much more significant.

Predictors and reduction techniques for irreducible reverse intertrochanteric fractures / 中华医学杂志(英文版)

BACKGROUND@#Reverse intertrochanteric fractures are usually initially treated with closed reduction. However, sometimes these fractures are not amenable to closed reduction and require open reduction. To date, few studies have been conducted on predictors of and reduction techniques for irreducible reverse intertrochanteric fractures. Therefore, this study aimed to summarize the displacement patterns of irreducible reverse intertrochanteric fractures and corresponding reduction techniques, and explore predictors of irreducibility.@*METHODS@#We reviewed 1174 cases of trochanteric fractures treated in our hospital from January 2006 to October 2018, 113 of which were reverse intertrochanteric fractures. An irreducible fracture was determined according to intra-operative fluoroscopy imaging after closed manipulation. Fractures were assessed for displacement patterns, radiographic features of irreducibility, and reduction techniques. Logistic regression analysis was performed on potential predictors for irreducibility, including gender, age, body mass index, AO Foundation/Orthopaedic Trauma Association (AO/OTA) classification, and radiographic features.@*RESULTS@#Seventy-six irreducible fractures were identified, accounting for 67% of reverse intertrochanteric fractures. Six patterns of fracture displacement after closed manipulation were identified; the most common pattern was medial displacement and posterior sagging of the femoral shaft relative to the head-neck fragment. Multivariate logistic regression analysis identified three predictors of irreducibility: a medially displaced femoral shaft relative to the head-neck fragment on the anteroposterior (AP) view (odds ratio [OR], 8.00; 95% confidence interval [CI], 3.04-21.04; P < 0.001), a displaced lesser trochanter (OR, 3.61; 95% CI, 1.35-9.61; P = 0.010), and a displaced lateral femoral wall (OR, 2.92; 95% CI, 1.02-8.34; P = 0.046).@*CONCLUSIONS@#A high proportion of reverse intertrochanteric fractures are not amenable to closed reduction. Six patterns of fracture displacement after closed manipulation were identified. Different reduction techniques are required for different displacement patterns. Predictors of irreducibility include a medially displaced femoral shaft relative to the head-neck fragment on the AP view, a displaced lesser trochanter, and a displaced lateral femoral wall. These patients warrant special consideration in terms of recognition and management.

Predictors and reduction techniques for irreducible reverse intertrochanteric fractures / 中华医学杂志(英文版)

Background@#Reverse intertrochanteric fractures are usually initially treated with closed reduction. However, sometimes these fractures are not amenable to closed reduction and require open reduction. To date, few studies have been conducted on predictors of and reduction techniques for irreducible reverse intertrochanteric fractures. Therefore, this study aimed to summarize the displacement patterns of irreducible reverse intertrochanteric fractures and corresponding reduction techniques, and explore predictors of irreducibility.@*Methods@#We reviewed 1174 cases of trochanteric fractures treated in our hospital from January 2006 to October 2018, 113 of which were reverse intertrochanteric fractures. An irreducible fracture was determined according to intra-operative fluoroscopy imaging after closed manipulation. Fractures were assessed for displacement patterns, radiographic features of irreducibility, and reduction techniques. Logistic regression analysis was performed on potential predictors for irreducibility, including gender, age, body mass index, AO Foundation/Orthopaedic Trauma Association (AO/OTA) classification, and radiographic features.@*Results@#Seventy-six irreducible fractures were identified, accounting for 67% of reverse intertrochanteric fractures. Six patterns of fracture displacement after closed manipulation were identified; the most common pattern was medial displacement and posterior sagging of the femoral shaft relative to the head-neck fragment. Multivariate logistic regression analysis identified three predictors of irreducibility: a medially displaced femoral shaft relative to the head-neck fragment on the anteroposterior (AP) view (odds ratio [OR], 8.00; 95% confidence interval [CI], 3.04-21.04; P < 0.001), a displaced lesser trochanter (OR, 3.61; 95% CI, 1.35-9.61; P = 0.010), and a displaced lateral femoral wall (OR, 2.92; 95% CI, 1.02-8.34; P = 0.046).@*Conclusions@#A high proportion of reverse intertrochanteric fractures are not amenable to closed reduction. Six patterns of fracture displacement after closed manipulation were identified. Different reduction techniques are required for different displacement patterns. Predictors of irreducibility include a medially displaced femoral shaft relative to the head-neck fragment on the AP view, a displaced lesser trochanter, and a displaced lateral femoral wall. These patients warrant special consideration in terms of recognition and management.

Analysis of Gene Mutation Types of Thalassemia in Quanzhou Area of Fujian Province in China / 中国实验血液学杂志

OBJECTIVE@#To investigate the gene mutation types and gene carrying rate of common thalassemia in patients with thalassemia in Quanzhou, and to analyze its molecular epidemiological characteristics in Quanzhou.@*METHODS@#546 patients with thalassemia diagnosed at the first hospital of Quanzhou from January 2017 to October 2018 were collected and retrospectively analyzed for their types of mutations and carrier rates.@*RESULTS@#Among the 4226 samples submitted, 546 positive samples were detected, the total carrying rate of the thalassaemia genes was 12.92%; the carrier rate of α-thalassemia was 8.16%; the carrier rate of β-thalassemia was 4.76%; There were more α-thalassemia missing patients than non-deleted patients. The Southeast Asian deletion type (-- /αα) was the most common one, with a composition ratio of 68.98%, which was followed by 22.61% (-α/αα), 2.61% (αα/αα), and 2.32% (αα/αα), 2.32% (αα/αα), 1.16% (-α/αα); 9 types of β-thalassemia gene mutations were detected. The most common three mutations were IVSII-654 (C→T, 42.29%), CD41-42 (-TTCT, 33.83%), CD17 (A→T, 12.94%). 2 cases of --/αα , 1 case of αα/ααα and 1 case of HKαα were detected.@*CONCLUSION@#This study shows that the gene carrying rate of thalassemia in Quanzhou is high and has diversity, which can provide some reference for the prevention and control of thalassemia in Quanzhou.

Application of the modified internal fixation method of minimally invasive percutaneous plate osteosynthesis in treatment of proximal humeral fracture / 北京大学学报(医学版)

OBJECTIVE@#To study the clinical outcomes and characteristics of fracture healing of a modified internal fixation method, which was implemented by placing four and two screws respectively at the proximal and distal end of the locking plate in the minimally invasive percutaneous plate osteosynthesis (MIPPO) for patients with proximal humeral fractures.@*METHODS@#Patients in Peking University Third Hospital from February 2010 to December 2016 were brought into this retrospective study. Based on different operation methods, they were divided into minimally invasive (MI) group and non-minimally invasive (non-MI) group, and the patients in MI group were performed with the modified internal fixation. In order to observe the varying efficacy for different fracture types between the two groups, we further investigated the patients with Neer two-part and three-part fracture, respectively. The follow-up parameters included general physical examination, X-ray, visual analogue scale (VAS) and Constant-Murley score.@*RESULTS@#A total of 117 patients with an average age of (61.5±16.2) years met the inclusion criteria, and MI group included 45 patients, non-MI group included 72 patients. According to the Neer classification, there were 46 cases of two-part fracture, 63 cases of three-part fracture and 8 cases of four-part fracture. In MI group, there were 17 males and 28 males with an average age of (62.2±17.1) years, including 18 cases of two-part fracture, 23 cases of three-part fracture and 4 cases of four-part fracture. In non-MI group, there were 27 males and 45 females with an average age of (60.1±17.7) years, including 28 cases of two-part fracture, 40 cases of three-part fracture and 4 cases of four-part fracture. There were no significant differences between the two groups in terms of gender (P=0.975), age (P=0.545) and fracture type (P=0.756). The average hospital-stay in MI group and non-MI group was (2.8±1.1) days and (4.3±1.3) days (P=0.023), the operation time was (67.8±14.9) min and (102.3±34.1) min (P<0.001), the blood loss was (21.3±6.5) mL and (181.5±55.6) mL (P<0.001), the Constant-Murley score was 6.1±0.9 and 6.5±0.8 (P=0.032) one week after surgery, and the Constant-Murley score was 66.1±4.3 and 63.4±4.9 (P=0.006) three months after surgery, MI group had significant advantages in these aspects. In terms of Neer two-part and three-part fracture, the VAS score (5.9±0.8) one week postoperatively and the Constant-Murley score (66.6±3.7) three months postoperatively were significantly superior in MI group (P<0.05). In MI group, delayed fracture healing occurred in 1 case (2.2%) and abduction was restricted in 1 case (2.2%). In non-MI group, delayed fracture healing occurred in 3 cases (4.2%) and abduction was restricted in 2 cases (2.8%). There were no internal fixation complications and humeral head necrosis in both groups.@*CONCLUSION@#Applying the modified internal fixation in MIPPO to cure proximal humeral fractures is effective clinically with thick callus formation occurring at the fracture site. The fracture can achieve normal healing and the shoulder functions can restore well, indicating the modified surgical method is a good treatment option.

Epidemiological Survey of Thalassemia in Women of childbearing age in Quanzhou Area of Fujian Province in China / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the gene prevalence and spectrum of thalassemia in the women of childbearing age in quanzhou area.</p><p><b>METHODS</b>Venous blood of the women were collected for study, all subjects were registered in each county of quanzhou area by using cluster sampling. Both the mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were used for screening thalassemia．Genotyping of the screened positive samples was performed by gap single polymerase chain reaction (gap-PCR) and reverse dot blot (RDB) hybridization．Unknown positive samples were analyzed with DNA sequencing.</p><p><b>RESULTS</b>Out of all 7 082 samples, Three hundred and eighty four were identified as thalassemia gene carriers with a carrying rate of 5.42 %. The α and β thalassemia were 3.21% and 2.15% respectively. -- /αα was the most common genotype with 68.72 % in mutation types of α thalassemia, In addition gene, 2 cases of --/αα and 1 case of αα/ααα were also detected. IVS-Ⅱ-654/N and CD41-42/N were the most common gentypes with 75.00 % in mutation types of β thalassemia gene, 5 cases were found to be α β compogite thalassemia.</p><p><b>CONCLUSION</b>The carrying rate of thalassemia gene in quanzhou area is higher, and with the most common gentypes including -- /αα、IVSⅡ-654(C→T)/N and CD41-42(-TTCT)/N. The study results are beneficial for the screening of thalassemia in the genetic consultation and the prenatal gene diagnosis.</p>

Construction of sub-unit dengue vaccines and analysis of its immunogenicity / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To construct sub-unit vaccines of dengue virus type 1 to 4 and to analyze its immunogenicity.</p><p><b>METHODS</b>Envelope domain III s of dengue serotypes 1 and 2, as well as 3 and 4, were spliced by a linker (Gly-Gly-Ser-Gly-Ser)3 and cloned into vector pET-30a, then transformed into E. coli to express recombinant fusion proteins. The recombinant proteins were purified by high-performance liquid chromatography and mixed to immunize BALB/c mice. The neutralizing antibodies were tested by neutralizing assay, as well as in newborn mice challenged intracranially with dengue virus type 1 to 4.</p><p><b>RESULTS</b>Mice immunized with proteins could produce neutralizing antibodies, with titers of 1:34. 9, 1: 45.3, 1: 24.7 and 1:38.4 for DEN-1 to 4 respectively. 100% newborn mice challenged with DEN-1 or 2 in combination with sera from mice immunized with recombinant proteins were protected, whereas 83% protection was obtained when challenged with DEN-3 or 4.</p><p><b>CONCLUSION</b>The recombinant proteins possess excellent immunogenicity to induce neutralizing antibodies and would be valuable for development of a tetravalent sub-unit vaccine.</p>

Application of purified recombinant outer membrane lipoprotein LipL32 in detecting antibodies among leptospirosis cases / 中华流行病学杂志

Objective To establish recombinant outer membrane lipoprotein LipL32-based antibody detection assays in identifying leptospirosis. Methods Recombinant leptospiral outer membrane protein LipL32 was obtained by genetic engineering method. This purified protein was used in the indirect and sandwich ELISA assays to test the antibodies in sera of human beings and rats, and the results were compared with those obtained by microscopy agglutination test (MAT) and imported ELISA kit. Results When the acute and convalescent phase specimens from 9 leptospiral patients were tested, the detected rates of three ELISAs were similar to the MAT. Among the 45 probable cases which MAT showed positive, 32 (71.11%) samples were positive by r32-I-ELISA, 36(80.00%) by r32-S-ELISA,while 28.89% (13/45) samples were positive and 55.56% (25/45)were suspicious by D.A.I-ELISA. The specificity of r32-I-ELISA and r32-S-ELISA were 97.10 % (67/69) for 69 specimens. 43 healthy specimens were negative by both r32-I-ELISA and r32-S-ELISA, 14 healthy specimens were negative by D.A.I-ELISA. Among 16 non-leptospirosis patients, two specimens were positive by r32-I-ELISA and r32-S-ELISA, D.A.I-ELISA and identified one positive specimen, while 12 specimens were suspicious by D.A.I-ELISA. For 10 syphilis specimens, data obtained through three ELISAs were in consistent with that by MAT. A sandwiched ELISA, using rLipL32 protein as the antigen was developed to detect rat sera. Considering MAT as standard test, the sensitivity and specificity were 86.75 % (131/151), 99.19 % (122/123) respectively with coincidence rate as 92.34% (253/274). Conclusion The recombinant protein LipL32 had high immunoresctivity and could be used as an antigen for the detection of panthogenic leptospirosis. In summary, the novel sandwiched ELISA with rLipL32 showed similar sensitivity and specificity to that of MAT in the antibody detection of rat leptospirosis. It was suitable for large scales field sero-epidemiological studies.

The less invasive stabilization system in treatment of complex proximal femoral fractures / 中华创伤骨科杂志

Objective To discuss the feasibility,indications,surgical techniques,and outcome con- cerning the application of less invasive stabilization system (LISS) for complex proximal femoral fractures.Methods We treated 12 complex proximal femoral fractures using femoral LISS reversely from June 2005 to May 2006. They were five complex intertrochanteric fractures and seven subtrochanteric ones.By AO classification,two were type 31-A2.2,two type 31-A2.3,one type 31-A3.3,one type 32-A3.1,three type 32-B1.1,one type 32-B2.1, and two type 32-B3.I.The patients were treated with closed or indirect reduction and fixation with percutaneous LISS plate reversely.Results There were no major postoperative complications in this study.The mean operation time was 65 minutes (range,50 to 90 minutes),the mean intra-operative blood loss was 142 milliliters (range,50 to 400 milliliters),and the mean postoperative hospital stay was 9.3 days (range,6 to 15 days).All patients had a clinical follow-up;the mean follow-up time was 7.2 months (range,3 to 14 months).Ten cases healed clinically three months postoperatively,one periprosthetic fracture healed four months and one pathological fracture healed six months after operation.At the final radiographic follow-up,no collapse,varus deformity,cutting-out,hardware failure,or avascular necrosis was found.Conclusions Femoral LISS used reversely can provide secure fixation for proximal femoral fractures biomechanically and anatomically.It is also easy and safe.It is particularly suitable for old patients with intertrochanteric fractures complicated with disorders of internal organs and severe osteoporosis or patients with complex proximal femoral fractures.It is important to be skillful in indirect reduction and positioning of guide wire into hole A,and to avoid immediate weight-bearing postoperatively.