Establishment and pathophysiological evaluation of a novel model of acute compartment syndrome in rats.

BACKGROUND: Researches have used intra-compartmental infusion and ballon tourniquest to create high intra-compartmental pressure in animal models of Acute Compartment Syndrome (ACS). However, due to the large differences in the modeling methods and the evaluation criteria of ACS, further researches of its pathophysiology and pathogenesis are hindered. Currently, there is no ideal animal model for ACS and this study aimed to establish a reproducible, clinically relevant animal model. METHODS: Blunt trauma and fracture were caused by the free falling of weights (0.5 kg, 1 kg, 2 kg) from a height of 40 cm onto the lower legs of rats, and the application of pressures of 100 mmHg, 200 mmHg, 300 mmHg and 400 mmHg to the lower limbs of rats using a modified pressurizing device for 6 h. The intra-compartmental pressure (ICP) and the pressure change (ΔP) of rats with single and combined injury were continuously recorded, and the pathophysiology of the rats was assessed based on serum biochemistry, histological and hemodynamic changes. RESULTS: The ΔP caused by single injury method of different weights falling onto the lower leg did not meet the diagnosis criteria for ACS (< 30 mmHg). On the other hand, a combined injury method of a falling weight of 1.0 kg and the use of a pressurizing device with pressure of 300 mmHg or 400 mmHg for 6 h resulted in the desired ACS diagnosis criteria with a ΔP value of less than 30 mmHg. The serum analytes, histological damage score, and fibrosis level of the combined injury group were significantly increased compared with control group, while the blood flow was significantly decreased compared with control group. CONCLUSION: We successfully established a new preclinical ACS-like rat model, by the compression of the lower leg of rats with 300 mmHg pressure for 6 h and blunt trauma by 1.0 kg weight falling.

Development and validation of a nomogram for predicting deep venous thrombosis in patients with pelvic and acetabular fractures: a retrospective cohort study : Predictive model for pelvic/acetabular fractures.

PURPOSE: To construct a novel nomogram model that can predict DVT and avoid unnecessary examination. METHODS: Patients admitted to the hospital with pelvis/acetabular fractures were included between July 2014 and July 2018. The potential predictors associated with DVT were analyzed using Univariate and multivariable logistic regression analysis. The predictive nomogram was constructed and internally validated. RESULTS: 230 patients were finally enrolled. There were 149 individuals in the non-DVT group and 81 in the DVT group. Following analysis, we obtained the final nomogram model. The risk factors included age (OR, 1.037; 95% CI, 1.013-1.062; P = 0.002), body mass index (BMI) (OR, 1.253; 95% CI, 1.120-1.403; P < 0.001); instant application of anticoagulant after admission (IAA) (OR, 2.734; 95% CI, 0.847-8.829; P = 0.093), hemoglobin (HGB) (OR, 0.970; 95% CI, 0.954-0.986; P < 0.001), D-Dimer(OR, 1.154; 95% CI, 1.016-1.310; P = 0.027) and fibrinogen (FIB) (OR, 1.286; 95% CI, 1.024-1.616; P = 0.002). The apparent C-statistic was 0.811, and the adjusted C-statistic was 0.777 after internal validations, demonstrating good discrimination. Hosmer and Lemeshow's goodness of fit (GOF) test of the predictive model showed a good calibration for the probability of prediction and observation (χ2 = 3.285, P = 0.915; P > 0.05). The decision curve analysis (DCA) and Clinical impact plot (CIC) demonstrated superior clinical use of the nomogram. CONCLUSIONS: An easy-to-calculate nomogram model for predicting DVT in patients with pelvic-acetabular fractures were developed. It could help clinicians to reduce DVT and avoid unnecessary examinations.

An exploratory study of pelvis anatomy to revise the bony canal used for LC2 screw insertion.

BACKGROUND: Percutaneous screw placement, especially the insertion of LC2 screws, is technically demanding. Although the traditional LC2 bony canal spans the anterior inferior iliac spine (AIIS) to the posterior superior iliac spines (PSIS), a high perforation rate has been reported. OBJECTION: The aim of this research was to design a revised bony canal, measure the canal width and length and guide the insertion of LC2 screws for pelvic fractures. MATERIALS AND METHODS: The plane tool in the Mimics analysis menu was used to draw a midplane connecting the midpoint between the anterior inferior spine and the PSIS upper flat region with pelvic CT data. The minimum widths of the upper, middle, lower surfaces of the tunnel and perforation rate were measured and compared. The ideal screw length was also measured along the longitudinal axis running through the midpoint of the midplane. RESULTS: The minimum widths of the upper, middle and lower surfaces of the revised canal were 3.63 mm, 7.7 mm, and 11.93 mm, respectively, in males and 5.97 mm, 9.93 mm, and 12.45 mm, respectively, in females. Significant differences were observed among the upper, middle and lower surfaces of the revised canal in male patients (P < 0.001). In female subjects, the upper canal surface was significantly different from the middle and lower canal surfaces (P < 0.001). The perforation rate was significantly decreased especially in females pelvic. The channel length passing through the midpoint of the narrowest position of the pelvis was 130.85 ± 8.02 mm in males and 124.30 ± 7.71 mm in females and was significantly different for male and female pelvises (P = 0.004). CONCLUSION: The LC2 screw should be inserted along the intersection line of the AIIS lateral wall and the iliac body. The screw should be inserted under the line between the midpoint of the AIIS and the PSIS upper flat region to ensure accuracy of placement. LC2 screws can be more easily inserted in males than in females, and the rate of cortical perforation can be significantly decreased under the guidance of the newly proposed canal.

Risk factors for preoperative deep venous thrombosis in hip fracture patients: a meta-analysis.

STUDY DESIGN: A meta-analysis. BACKGROUND: Hip fracture (HF), as common geriatric fracture, is related to increased disability and mortality. Preoperative deep vein thrombosis (DVT) is one of the most common complications in patients with hip fractures, affecting 8-34.9% of hip fracture patients. The study aimed to assess the risk factors of preoperative DVT after hip fractures by meta-analysis. METHODS: An extensive search of the literature was performed in the English databases of PubMed, Embase, and the Cochrane Library; and the Chinese databases of CNKI and WAN FANG. We collected possible predictors of preoperative DVT from included studies, and data analysis was conducted with RevMan 5.3 and STATA 12.0. RESULTS: A total of 26 English articles were included, and the rate of DVT was 16.6% (1627 of 9823 patients) in our study. Our findings showed that advanced age [p = 0.0003, OR = 0.13 95% CI (0.06, 0.21)], female patients [p = 0.0009, OR = 0.82 95% CI (0.72, 0.92)], high-energy injury [p = 0.009, OR = 0.58 95% CI (0.38, 0.87)], prolonged time from injury to admission [p < 0.00001, OR = 0.54 95% CI (0.44, 0.65)], prolonged time from injury to surgery [p < 0.00001, OR = 2.06, 95% CI (1.40, 2.72)], hemoglobin [p < 0.00001, OR = - 0.32 95% CI (- 0.43, - 0.21)], coronary heart disease [p = 0.006, OR = 1.25 95% CI (1.07, 1.47)], dementia [p = 0.02, OR = 1.72 95% CI (1.1, 2.67)], liver and kidney diseases [p = 0.02, OR = 1.91 95% CI (1.12, 3.25)], pulmonary disease [p = 0.02, OR = 1.55 95% CI (1.07, 2.23)], smoking [p = 0.007, OR = 1.45 95% CI (1.11, 1.89)], fibrinogen [p = 0.0005, OR = 0.20 95% CI (0.09, 0.32)], anti-platelet drug [p = 0.01, OR = 0.51 95% CI (0.30, 0.85)], C-reactive protein [p = 0.02, OR = 5.95 95% CI (1.04, 10.85)], < 35 g/l albumin [p = 0.006, OR = 1.42 95% CI (1.1, 1.82)], and thrombosis history [p < 0.00001, OR = 5.28 95% CI (2.85, 9.78)] were risk factors for preoperative DVT. CONCLUSIONS: Many factors, including advanced age, female patients, high-energy injury, prolonged time from injury to admission, prolonged time from injury to surgery, patients with a history of coronary heart disease, dementia, liver and kidney diseases, pulmonary disease, smoking, and thrombosis, fibrinogen, C-reactive protein, and < 35 g/l albumin, were found to be associated with preoperative DVT. Our findings suggested that the patient with above characteristics might have preoperative DVT. LEVEL OF EVIDENCE: Level III.

Silica-Coated, Waxberry-like Surface-Enhanced Raman Resonant Scattering Tag-Pair with Near-Infrared Raman Dye Encoding: Toward In Vivo Duplexing Detection.

Surface-enhanced Raman resonant scattering (SERRS) tags encoded with near-infrared (NIR) Raman reporters showed great potential for in vivo detection owing to their ultrasensitivity. However, in vivo signal stability of such tags is a remaining problem due to the lack of suitable silica coating method because the weakly adsorbed NIR reporters tend to detach from traditional gold nanosubstrates in the ethanol-rich and high pH conditions, which are commonly used for silica coating. Herein, we propose a silica coating method for NIR SERRS tags by using waxberry-like gold nanoparticles (NPs) as substrates. The lipid bilayer of the NPs played a crucial role in the coating, which can encapsulate the NIR Raman reporter via hydrophobic interactions and prevent the interference from a harsh medium. Thus, the silica-coated tags well preserved ultrasensitivity of bare tags and simultaneously gained satisfactory signal stability in vivo. Moreover, the coating method is compatible for the encapsulation of a variety of thiol group-free NIR reporters (as exemplified by DTTC, Cy7, IR792, and DIR), relying on which a tag-pair with distinguishable peaks can be screened (labeling with DTTC and Cy7, respectively). In vivo duplexing detection revealed that the tag-pair-labeled liposome was cleared faster in the liver than polydopamine NPs within one mouse. The developed method paves an easy way for gaining high-quality SERRS tags and will promote their in vivo multiplex analysis and diagnostics applications.

Neutrophil to lymphocyte ratio and fracture severity in young and middle-aged patients with tibial plateau fractures.

PURPOSE: The neutrophil-to-lymphocyte ratio (NLR) has recently been found to be closely associated with the severity of trauma. This study aimed to analyze the correlation between the imaging severity of isolated tibial plateau fractures (TPFs) and the NLR in the blood. METHODS: A total of 223 patients with isolated TPFs were enrolled in this retrospective study over five years. The data at hospital admission were extracted from an electronic database. Schatzker classification was performed according to the imaging data by two experienced orthopaedic surgeons. All patients were divided into two groups: group 1 included patients with mild-to-moderate fractures (Schatzker types I-IV), and group 2 included patients with severe fractures (Schatzker types V-VI). The NLR levels at hospital admission were statistically compared between the two groups. RESULTS: The blood NLR, hemoglobin level, red blood cell count, neutrophil count, platelet count, time from injury to admission, total protein, and Na+ levels were significantly different among the two groups. According to the receiver operating characteristic (ROC) curve, the cutoff for the NLR was 5.8. ROC curve analysis showed that the sensitivity of an NLR ≥ 5.8 to predict severe TPFs was 53.4%, and the specificity was 70.7%. In the multivariate analysis, NLR ≥ 5.8 and haemoglobin < lower limit appeared to be independent predictors of severe TPFs. CONCLUSIONS: Our study is the first to demonstrate that the NLR level appears to be a useful biomarker for predicting the severity of isolated TPFs in young and middle-aged adults.

Epidemiologic characteristics of traumatic fractures in elderly patients during the outbreak of coronavirus disease 2019 in China.

PURPOSE: This study aimed to describe the epidemiologic characteristics of fracture in the elderly during the COVID-19. METHODS: This was a retrospective multi-centre study, which included patients who sustained fractures between 20 January and 19 February 2020. The collected data included patients' demographics (age and gender), injury-related (injury type, fracture location, injury mechanism, places where fracture occurred), and treatment modality. SPSS 23.0 was used to describe the data and perform some analysis. RESULTS: A total of 436 patients with 453 fractures were included; there were 153 males and 283 females, with an average age of 76.2 years (standard deviation, SD, 7.7 years; 65 to 105). For either males or females, 70-74 years was the most commonly involved age group. A total of 317 (72.7%) patients had their fractures occurring at home. Among 453 fractures, there were 264 (58.3%) hip fractures, accounting for 58.3%. Fall from standing height was the most common cause of fracture, making a proportion of 89.4% (405/453). Most fractures (95.8%, 434/453) were treated surgically, and 4.2% (19/453) were treated by plaster fixation or traction. Open reduction and internal fixation (ORIF) was the most used surgical method, taking a proportion of 49.2% (223/453). CONCLUSION: These findings highlighted the importance of primary prevention (home prevention) measures and could be used for references for individuals, health care providers, or health administrative department during the global pandemic of COVID-19.

Polystyrene Encapsulated SERS Tags as Promising Standard Tools: Simple and Universal in Synthesis; Highly Sensitive and Ultrastable for Bioimaging.

Surface coating determined the sensitivity and stability of surface-enhanced Raman scattering (SERS) tags in bioanalysis. The reported various coatings suffered from the drawbacks of a lack of rigidity, stability, or synthesis versatility. Herein, we demonstrated robust polystyrene (PS) coated SERS tags that could be prepared by an easy and universal approach. Taking advantages of biocompatible, transparent, compact properties of PS shell, the coated tags showed satisfactory sensitivity, biocompatibility, and superior structural stability in cell and in vivo imaging applications. More importantly, the PS coating strategy allowed for the encapsulation of SERS tags encoded with not only thiolated but also nonthiolated Raman reporters without loss of sensitivity, as exemplified in the synthesis of 9 different resonant dye-encoded tags. Moreover, the coating of SERS tags with various kinds of substrates was achieved via the same standard protocol. Comparing with widespread silica coated tags, the PS coated ones were more stable in harsh conditions and had an easily expanded ultrasensitive (resonant) tags library with much lower cost (no need of expensive sulfhydryl/isothiocyano reporters with limited types), illustrating great promise as standard analytical tools of commercialized value for bioanalysis, medical diagnostics, and environmental science studies.

Minimally invasive treatment for fractures of lower extremity amputees using a rapid reductor.

PURPOSE: A traction table is recommended for lower limb fractures, while it is unavailable for amputees to immobilize the ipsilateral foot to remain stationary and reduce the fracture. For these patients, our rapid reductor can be applied to guarantee stable fixation and optimal reduction, allowing satisfactory implant positioning. This study aims to evaluate the prognosis of amputee patients with lower limb fractures treated by minimally invasive techniques that employ a rapid reductor to reduce the fracture. METHODS: Between 2013 and 2014, 11 cases of amputees suffering from a lower limb fracture were enrolled in the study, including four transtibial amputees with a tibial plateau fracture, three transtibial amputees with a femoral shaft fracture, and four transfemoral amputees with a femoral neck fracture. All fractures involved the amputated ipsilateral lower limbs, which were all reduced in a closed fashion using a rapid reductor. During the operation, the rapid reductor was connected to the injured limb for skeleton traction to reduce the fracture and then used to maintain the reduction for subsequent minimally invasive fixation. The operation time, reduction time, fluoroscopy time, and intra-operative blood loss were recorded. Follow-ups were conducted to evaluate the union of the fractures and the functional recovery. RESULTS: All 11 cases were treated successfully using this minimally invasive technique, with anatomical or nearly anatomical reduction reached in all fractures. The average operative time, reduction time, fluoroscopy time, and intra-operative blood loss were 60 minutes (range, 46-90 minutes), 13.2 minutes (range, 7-20 minutes), 19.8 seconds (range, 6-65 seconds), and 95 mL (range, 80-170 mL), respectively. No incidents of reductor-induced complications occurred during the operation. Patients were followed up for an average of 20.8 months (range, 18-24 months). All fractures healed well on an average of six months. At the latest follow-up, all 11 cases reported satisfactory functional recovery of the fixed limbs, which were similar to that before the fractures. CONCLUSIONS: The rapid reductor can be used to efficiently reduce and maintain ipsilateral fractures of the amputated lower extremity in a closed fashion, which can facilitate minimally invasive fixation of the fractures. The patients can achieve excellent outcomes.

Computational analysis on the feasibility of transverse iliosacral screw fixation for different sacral segments.

PURPOSE: To evaluate the feasibility of transverse iliosacral (TIS) screw placement in different segments of the sacrum and measure the parameters of the unilateral iliosacral (IS) screw in the case that cannot be inserted the TIS screw. METHODS: This study used 100 pelvic continuous computed tomography images. Mimics (Materialise Interactive Medical Image Control System) was used to reconstruct the three-dimensional pelvis model. All sacrums were divided into the normal group and dysmorphic group. Any difference in osseous fixation pathway (OFP) diameter in the first two segments between both groups was investigated. In dysmorphic sacrums, the optimal inserting angle and length of the unilateral S1 screw were measured. The number of foramen in every sacrum was recorded. RESULTS: Thirty-two sacrums had sacral dysmorphism. The OFP diameter for the S2 TIS screw in the dysmorphic group was larger than that in the normal group (p = 0.02). Receiver operating characteristic curve analysis indicated the cutoff values as 20.55 mm and 15.18° for the S1 front edge height and S1S2 angle, respectively. In the dysmorphic case, the unilateral S1 IS screw should be inserted with a cephalad incline angle of 36.14 ± 5.97° and a ventrally incline angle of 37.33 ± 4.64°. S3 TIS screw placement rate was 53.1% in the dysmorphic group. CONCLUSIONS: The most common cause of sacral dysmorphism is the fusion of the L5 to the true S1. In dysmorphic sacrums, the unilateral IS screw should be placed obliquely in the S1 segment, and the S2 segment usually has a sufficient OFP for the TIS screw. Using S3 TIS screw and two TIS screws in the first segment technique is not recommended because of a high risk.

Size of greater tuberosity fragment: a risk of iatrogenic injury during shoulder dislocation reduction.

PURPOSE: Shoulder dislocation with greater tuberosity fractures (GTF) is becoming increasingly common, as is the number of cases of iatrogenic humeral neck fractures (IHNF) during reduction. This study investigated the relationship between size of greater tuberosity fragment and occurrence of IHNF in patients with shoulder dislocation and GTF. METHODS: A retrospective study was made to identify all patients presenting with shoulder dislocation with GTF between September 2014 and July 2016. There were 74 patients with an average age of 52.4 years (range 18-84 years) representing 76 cases of shoulder dislocation associated with GTF. Patient age, injury mechanism and location, treatment waiting time, and reduction method were noted. Using conventional anterior-posterior view radiographs, three points were identified as A, B, and C. Distance ratios between AC and AB were calculated, then the resulting ratio was compared to a critical value of 0.4. RESULTS: More iatrogenic fractures occurred in cases where the AC/AB ratio exceeded 0.4. Most (13) occurred during emergency Hippocratic manual reduction. Only five of 18 iatrogenic fractures (27.78%) occurred during surgery while under traction. Women ran a higher risk of iatrogenic fracture than men (female/male ratio 8:1). On average, women were older than men at the time of fracture (59.75 years for women vs. 42 years for men). CONCLUSIONS: A statistically significant relationship exists between size of greater tuberosity fragment and occurrence of iatrogenic humeral neck fractures during the reduction of shoulder dislocation. The larger the greater tuberosity fragment, the higher the incidence of iatrogenic humeral neck fractures. For such fracture dislocations, we recommend open reduction with internal fixation directly and using a Kirschner wire in advance to reinforce the proximal humerus before reduction of the shoulder.

Measuring femoral neck torsion angle using femoral neck oblique axial computed tomography reconstruction.

PURPOSE: To propose a novel method for measuring the femoral neck torsion angle (FNTA) with femoral neck oblique axial computed tomography (CT) reconstruction. METHODS: Fifty-five patients (24 females, 31 males; mean age 48.8 years [range, 20-91 years]) were included in the study. CT scans were performed on the left femurs of 27 patients and the right femurs of the remaining 28 patients. The images were analyzed independently by two observers using oblique axial femoral neck CT reconstruction. Intra-observer and inter-observer agreement was calculated as intraclass correlation coefficient (ICC). RESULTS: FNTA can be measured with high intra-observer (ICC = 0.961) and high inter-observer (ICC = 0.982) agreement. Mean FNTA was slightly larger in women than in men, and the mean left FNTA was slightly larger than the right, but neither difference was statistically significant. CONCLUSIONS: Femoral neck oblique axial CT reconstruction can be used to obtain accurate measurement of FNTA with good reproducibility. No significant differences were found in FNTA between sexes or sides.

Specifying the Starting Point for S1 Iliosacral Screw Placement in the Dysmorphic Sacrum.

BACKGROUND: Sacral dysmorphism is not uncommon and complicates S1 iliosacral screw placement partially because of the difficulty of determining the starting point accurately on the sacral lateral view. We propose a method of specifying the starting point. METHODS: The starting point for the S1 iliosacral screw into the dysmorphic sacrum was specifically set at a point where the ossification of the S1/S2 intervertebral disc (OSID) intersected the posterior vertebral cortical line (PVCL) on the sacral lateral view, followed by guidewire manipulation and screw placement on the pelvic outlet and inlet views. Computer-simulated virtual surgical procedures based on pelvic computed tomography (CT) data on 95 dysmorphic sacra were performed to determine whether the starting point was below the iliac cortical density (ICD) and in the S1 oblique osseous corridor and to evaluate the accuracy of screw placement (with 1 screw being used, in the left hemipelvis). Surgical procedures on 17 patients were performed to verify the visibility of the OSID and PVCL, to check the location of the starting point relative to the ICD, and to validate the screw placement safety as demonstrated with postoperative CT scans. RESULTS: In the virtual surgical procedures, the starting point was consistently below the ICD and in the oblique osseous corridor in all patients and all screws were Grade 1. In the clinical surgical procedures, the OSID and PVCL were consistently visible and the starting point was always below the ICD in all patients; overall, 21 S1 iliosacral screws were placed in these 17 patients without malpositioning or iatrogenic injury. CONCLUSIONS: On the lateral view of the dysmorphic sacrum, the OSID and PVCL are visible and intersect at a point that is consistently below the ICD and in the oblique osseous corridor, and thus they can be used to identify the starting point. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Extra-articular screw placement strategy in Stoppa approach based on three-dimensional reconstruction model.

The study aimed to explore an extra-articular screw placement strategy in Stoppa approach. Radiographic data of patients who underwent pelvic computed tomography from January 2016 to June 2017 were imported into Materiaise's interactive medical image control system software for three-dimensional reconstruction. Superior and lower margins of acetabulum and ipsilateral pelvic brim could be observed simultaneously through inlet-obturator view. A horizontal line from superior acetabular margin intersected pelvic brim at point "A" and another vertical line from lower margin intersected pelvic brim at point "B" were drawn, respectively. Lengths form sacroiliac joint to "A" (a), "A" to "B" (b), and "B" to pubic symphysis (c) were measured. Patients were divided into four groups depending on gender and side difference of measured hemi-pelvis: male left, male right, female left, and female right. Lengths of adjacent holes (d) and spanning different holes (e) of different plates were also measured. Mean lengths of a, b, c in four groups were 40.94 ± 1.85 mm, 40.09 ± 1.93 mm, 41.78 ± 3.62 mm, and 39.77 ± 2.23 mm (P = 0.078); 40.65 ± 1.58 mm, 41.48 ± 1.64 mm, 40.40 ± 1.96 mm, and 40.66 ± 1.70 mm (P = 0.265); 57.03 ± 3.41 mm, 57.51 ± 3.71 mm, 57.84 ± 4.40 mm, and 59.84 ± 4.35 mm (P = 0.165), respectively. Mean d length of different plates was 12.23 mm. Average lengths spanning 1, 2, 3 and 4 holes were 19.33 mm, 31.58 mm, 43.80 mm, and 55.93 mm. Our data showed that zones a and c could be safely inserted three and four screws. Penetration into hip joint could be avoided when vacant 3-hole drilling was conducted in zone b. Fracture line in zone b could serve as a landmark for screw placement.

Chronic intermittent hypobaric hypoxia ameliorates osteoporosis after spinal cord injury through balancing osteoblast and osteoclast activities in rats.

Introduction: As a common complication of spinal cord injury (SCI), most SCI patients suffer from osteoporosis. In our previous study, chronic intermittent hypobaric hypoxia (CIHH) could promote bone fracture healing. We speculated that it may act a role in the progression of osteoporosis. The current study purposed to explore the role of CIHH in the osteoporosis triggered by SCI in rats. Methods: A SCI-induced SCI model was established by completed transection at T9-T10 spinal cord of Wistar rats. One week after SCI, the rats were conducted to CIHH treatment (PB = 404 mmHg, Po2 = 84 mmHg) 6 hours a day for continuously 7 weeks. Results: The results of X-radiography and Micro-CT assessment demonstrated that compared with sham rats, the areal bone mineral density (BMD), bone volume to tissue volume, volumetric BMD, trabecular thickness, trabecular number, and trabecular connectivity were decreased. Trabecular bone pattern factor, trabecular separation, as well as structure model index were increased at the distal femur and proximal tibia of SCI rats, which were effectively reversed by CIHH treatment. Histomorphometry showed that CIHH treatment increased bone formation of SCI rats, as evidenced by the increased osteoid formation, the decreased number and surface of TRAP-positive osteoclasts. Furthermore, ELISA and real time PCR results showed that the osteoblastogenesis-related biomarkers, such as procollagen type 1 N-terminal propeptide, osteocalcin in serum, as well as ALP and OPG mRNAs in bone tissue were decreased, while the osteoclastogenesis-related biomarkers, including scleorostin in serum and RANKL and TRAP mRNAs in bone tissue were increased in SCI rats. Importantly, the deviations of aforementioned biomarkers were improved by CIHH treatment. Mechanically, the protective effects of CIHH might be at least partly mediated by hypoxia-inducible factor-1 alpha (HIF-1α) signaling pathway. Conclusion: The present study testified that CIHH treatment ameliorates osteoporosis after SCI by balancing osteoblast and osteoclast activities in rats.

A new classification for quadrilateral plate fracture of acetabulum.

BACKGROUND: Recently, quadrilateral plate (QLP) fractures of acetabulum have attracted increasing attention. However, evidence for the appropriate classification of QLP fractures is still lacking, making it difficult to understand and manage these fractures. This study aimed to introduce a new classification for QLP fractures and evaluate its reproducibility. METHODS: A series of 1101 consecutive patients with acetabular fractures from 8 level-I trauma centers were enrolled in this study. All patients underwent preoperative radiograph and computed tomography imaging. QLP fractures were identified and classified using the new and Judet-Letournel classification system. The inter- and intra-observer reliabilities (kappa coefficients, κ) of these two systems were investigated by 4 observers. Furthermore, surgical approaches and fixation methods for each fracture type are described. RESULTS: In total, 243 (243/1101, 22%) patients with QLP fractures were identified and included in this analysis. The mean κ value of the intra-observer reliability was 0.84 (range, 0.763-0.919) for the new classification, indicating excellent agreement, and the inter-observer reliability was 0.762 (range, 0.625-0.876), indicating substantial agreement. The values were 0.649 (range, 0.523-0.708) and 0.584 (0.497-0.646), respectively, according to the Judet-Letournel classification. Six cases (6/243, 2.5%) could not be classified using the Judet-Letournel classification. The selection of surgical approaches and fixation methods depends on the fracture type; however, an anterior intra-pelvic approach and buttressing fixation using the plate or screw are preferred for QLP fractures. CONCLUSION: This study presents a new classification for QLP fractures, showing higher intra- and inter-observer reliabilities than those obtained using the Judet-Letournel classification. This allowed us to obtain an in-depth and comprehensive understanding of QLP fractures. Additionally, the new classification might guide further studies on surgical strategies for QLP fractures. LEVEL OF EVIDENCE: Level II.

Comparison of surgical efficacy of locking plates and interlocking intramedullary nails in the treatment of proximal humerus fractures.

BACKGROUND: The objective of this study was to evaluate the efficacy of locking plates versus interlocking intramedullary nails in the treatment of proximal humerus fractures to provide clinical data support and theoretical guidance. METHODS: Patients with proximal humerus fracture from the Third hospital of Shijiazhuang city and Third hospital of Hebei medical university and from January 2017 to June 2019 were selected, included and divided into the locking plate group and the interlocking intramedullary nail group according to the intervention received. Information pertaining to the perioperative period (operation time, hospital stay, blood loss, etc.) of patients in both groups was collected. VAS pain scores, shoulder activity Constant-Murley scores and postoperative complications were documented. The perioperative data of the two groups were compared, and P < 0.05 was considered statistically significant. RESULTS: A total of 64 patients were enrolled, including 36 patients in the locking plate group, with a mean age of 61.3 ± 13.9 years, while the mean age of the interlocking intramedullary nail group was 65.6 ± 11.2 years. There was no statistical difference in gender, affected side, injury mechanism and Neer classification between the two groups (P > 0.05). However, the average operation time of the locking plate group was shorter than that of the interlocking nail group (84.9 ± 11.7 vs. 102.6 ± 22.1 min, P = 0.00), and the intraoperative blood loss of the locking plate group (137.4 ± 16.8 ml) was higher than that of the interlocking nail group (72.5 ± 10.5 ml, P = 0.00). There was no significant difference in the VAS score and Constant-Murley score between these two groups at the final follow-up. CONCLUSION: Interlocking intramedullary nails are more minimally invasive than locking plates, but fracture reduction and fixation take longer. There was no significant difference in pain and shoulder function scores between the two internal fixation strategies for the treatment of proximal humerus fracture.

Three-dimensional mapping study of pure transverse acetabular fractures.

BACKGROUND: To describe and analyze the morphological characteristics, location and frequency of pure transverse acetabular fracture lines through fracture mapping and quantitative measurements. METHODS: Transverse fractures were retrospectively reviewed and analyzed. All computed tomography (CT) data were used for reconstruction and manual reduction. The reductive fracture fragments were graphically overlaid onto a three-dimensional (3D) right hemipelvis template. Then, the fracture lines were accurately depicted onto the surface of the 3D template. The fracture lines were overlapped onto the model to create the 3D fracture map and heatmap. All cases were subdivided into infratectal (62-B1.1), juxtatectal (62-B1.2), and transtectal (62-B1.3) types based on the AO Foundation/Orthopedic Trauma Association (AO/OTA) classification. Some anatomic parameters of the transverse fractures were also analyzed in these 3 groups. RESULTS: Our study included forty-nine transverse fractures from 32 male and 17 female patients (mean age, 42 years; range 21-74 years) and included 19 type 62-B1.1, 17 type 62-B1.2, and 13 type 62-B1.3 fractures. The average anterior rim fracture angle was 70.0° (± 11.6°), and the posterior rim fracture angle was 92.4° (± 28.5°). The anterior rim fracture angles in 40 cases (40/49, 81.6%) fell within a wide range between 63° and 80°. On the heatmap, the hot zones were located on the highest position of the cotyloid fossa and the narrowed region, and the cold zone was on the inferior third of the articular surface. For type 62-B1.3 fractures, the hot zone was located on the posterior of the acetabular dome. There were no significant differences in anterior rim fracture angle and anterior height among the three patterns (P = 0.071, P = 0.072). Post hoc tests of the posterior rim fracture angle and the posterior height revealed significant differences among fracture subtypes (P < 0.01). The posterior intra-articular fracture line was significantly longer than the anterior intra-articular fracture line in type 62-B1.1 and type 62-B1.2 fractures (P < 0.01). CONCLUSION: The fracture lines of transverse fractures through the anterior rim were concentrated on the narrowed zone, and the posterior fracture lines were diffusely distributed. The intra-articular fracture line distribution was focused on the superior and middle thirds of the joint surface. The recurrent fracture lines involving the weight-bearing dome mainly converged on the posterior region of the roof.

Fracture Mapping of Both-Column Acetabular Fractures.

OBJECTIVES: To characterize the location and frequency of the fracture lines and comminution zones of both-column fractures using fracture mapping. METHODS: Both-column fractures were retrospectively reviewed in 4 Level 1 trauma centers. Mimics software was used to reconstruct the both-column fractures and simulate the fracture reduction. Then, the fracture lines and the intra-articular and extra-articular comminution zones were drawn on a 3-dimensional innominate bone template. The distribution of fracture lines and fracture fragments were also mapped on the two-dimensional template of the acetabulum. All the included patients were divided into low-variety group and high-variety group according to the anterior column fracture line above or below the anterior superior spine. The anatomical characteristics of the posterior wall fragment were also analyzed in these 2 groups. RESULTS: Seventy-eight patients with both-column fracture were included. The T type or inverted Y type main fracture lines divided the innominate bone into low-variety (n = 11) and high-variety (n = 67) both-column fractures. The extra-articular comminution zones are usually distributed between the posterior iliac fragment and anterior column fragment. High-variety type both-column fractures are usually combined with high and sharp posterior wall fragments, whereas low-variety type both-column fractures are usually accompanied by low and flat posterior wall fragments. The comminution zones in the acetabulum are mostly concentrated in the anterior and inferior parts of the acetabulum. CONCLUSIONS: The innominate bone is divided into 3 major parts in the both-column fracture, and the fracture center is located at the proximal of the acetabular dome. The both-column fractures are divided into low-variety and high-variety patterns. The location of the anterior column fracture determined the characteristics of the posterior wall fragment.

Displacement Pattern of Anterior and Posterior Column Fragments in Both-Column Acetabular Fractures: A 3D Reconstruction-Based Study.

Background: Few studies have been conducted to examine the displacement characteristics of both-column acetabular fractures (BCAFs). The goal of this study was to investigate the displacement pattern of anterior column (AC) and posterior column (PC) fragments in BCAFs using 3D virtual software. Materials and Methods: BCAFs were retrospectively reviewed, and 81 patients were enrolled. Computed tomography (CT) images were imported into Mimics software. A 3D model of each pelvis was generated. Four marked points and the rotation angle of each of the injured ACs and PCs were identified. The fracture fragments were reduced virtually using the software, and the change in coordinates of the marked points after reduction was recorded while the rotation angle was measured. The measurements of positional and directional displacement were analysed using the Mann-Whitney U test and the binomial test, respectively. Results: There was a propensity for AC fragments to shift superomedially and to rotate externally (p < 0.001). Additionally, the posteroinferior fracture area of AC fragments showed the greatest displacement (p < 0.05). PC fragments moved superomedially (p < 0.001) and moved more at the proximal end than the distal end (p < 0.001). PC displacement was always accompanied by internal rotation (p < 0.001). Greater AC displacement was observed in the fracture area further away from the acetabulum (p < 0.05). Greater rotation was observed for the AC than the PC (p < 0.001). Conclusion: After a BCAF occurs, there are regular patterns regarding the direction and distance of AC and PC fragment displacement. Information on these patterns may provide insight into the injury mechanism and fracture morphology and facilitate surgical decision-making for orthopaedic trauma surgeons.