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Tibial plateau fracture is a common acute trauma of the knee joint. At present, there are many studies on its classification and treatment, and minimally invasive treatment has become a research hotspot and mainstream direction of tibial plateau fracture. We summarized the clinical results of minimally invasive treatment of more than 300 cases of tibial plateau fractures, and proposed the concept of core weight-bearing area on tibial plateau, that is, the core weight-bearing area of the tibial plateau of the knee joint under normal motion statuswhile walking and moderate-intensity running. We performed thinsection CT scanning of the knee joint in a male volunteer for three-dimension finite element modeling.The results showed that during the walking state (the load was twice that of gravity), the core weight-bearing area of the medial and lateral plateaus was 389 mm 2 and 363 mm 2, accounting for 33.2% and 42.9% of tibial plateau, respectively;during the moderate-intensity running state (the load was four times that of gravity), the core weight-bearing area of the medial and lateral plateaus was 418 mm 2 and 406 mm 2, accounting for 35.6% and 48.0%of tibial plateau, respectively. Accordingly, tibial plateau fractures are supposed to be divided into core weight-bearing fracture and non-core weight-bearing fracture, and there are significant differences in the treatment ofthese twokinds of fractures: reduction is more demanding for core weight-bearing fracture,and the fracture involves the core area closely, the anatomical reduction is sought; for non-core weight-bearing area, the reduction requirements can be appropriately low demanded, and even in some cases , for example simple avulsion fracture, marginal fracture, some tibial plateau Hoffa fractures,can be treated conservatively. In summary, during clinical diagnosis and treatmentpractice, orthopedic surgeons should take the core weight-bearing area fracture as the core of diagnosis and treatment, strictly evaluate the extent of fracture involvement, select targeted internal fixation materials, and target to promote more accurate, minimally invasive, and individualized treatment of tibial plateau fractures.
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Objective:To explore the factors related to functional recovery of the knee in patients with tibial plateau fracture complicated with intercondylar ridge fracture.Methods:Included in this retrospective study were 63 patients who had been treated at Emergency Center of Trauma, The Third Hospital of Hebei Medical University from January to June 2019 for tibial plateau fracture complicated with intercondylar ridge fracture. They were 43 males and 20 females, aged from 18 to 66 years (average, 43.9 years). According to our comprehensive classification of tibial plateau fractures, there were 27 simple ones (20 cases of type Ⅰ and 7 cases of type Ⅱ) and 36 complicated ones (16 cases of type Ⅲ, 17 cases of type Ⅳ, one of type Ⅴ and 2 cases of type Ⅵ). To screen out major influencing factors, a multiple linear regression model was used to analyze the 12 factors that might affect functional recovery of the knee by the Hospital for Special Surgery (HSS) scoring: age, gender, occupation, fracture type, way of medical payment, cause of injury, operation method, starting time for rehabilitation, postoperative brace installation, time from injury to operation, length of hospital stay, and presence or absence of a free intercondylar ridge fracture fragment.Results:The 63 patients were followed up for 6.0 to 7.1 months (average, 6.1 months). The HSS knee scores ranged from 45 to 100 points (average, 92.4 points). The HSS knee scores were significantly different between different fracture types ( P<0.05). The HSS scores were significantly higher for the patients without a free intercondylar ridge fracture fragment than for those with ( P<0.05). Multiple linear regression model analysis of the 5 variables with P<0.02 in the single factor analysis (age, fracture type, way of medical payment, hospital stay and presence or absence of a free intercondylar ridge fracture fragment) and HSS scores showed that only fracture type and presence or absence of a free intercondylar ridge fracture fragment had a significant impact on the knee function. Their regression equation was Y=125.591-7.790a-17.277b (Y indicates HSS score, a indicates fracture type and b indicates presence or absence of a free intercondylar ridge fracture fragment). Conclusions:The short-term prognosis for tibial plateau fractures of comprehensive types Ⅰ&Ⅱ (simple ones) may be better than that for tibial plateau fractures of comprehensive types Ⅲ, Ⅳ, Ⅴ&Ⅵ (complicated ones). For patients with a free intercondylar ridge fracture fragment on their lateral knee X-ray film, effective reduction and fixation is indicated but is not for those without.
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Objective:To evaluate our self-designed easily-breaking compression bone bolt plus bone plate in the treatment of tibial plateau fracture.Methods:From July 2018 to December 2018, 12 patients with tibial plateau fracture were treated at Emergency Center of Trauma, The Third Hospital of Hebei Medical University using our self-designed easily-breaking compression bone bolt plus bone plate. They were 8 males and 4 females, aged from 20 to 65 years (average, 45.6 years), with 6 left sides and 6 right sides injured. According to Schatzker classification, there were one case of type I, 3 cases of type Ⅱ, 3 cases of type Ⅲ, 2 cases of type Ⅳ, one case of type Ⅴ and 2 cases of type Ⅵ. The width of tibial plateau was measured and compared before and after operation on X-ray films. Operation time, blood loss and fracture union time were recorded. Loss of reduction and postoperative complications were followed up. Knee function was evaluated at the final follow-up by Rasmussen scoring.Results:For this cohort, operation time averaged 54.6 min, blood loss 25 mL, and fracture union time 17.2 weeks. No nonunion or delayed union was observed. The postoperative width of tibial plateau was (78.9±7.2) mm, significantly narrower than the preoperative value [(87.4±6.1) mm] ( P < 0.05). No loss of reduction or surgical complications occurred postoperation. Deep venous thrombosis of the lower extremity developed in 2 patients but recovered after treatment. The Rasmussen scoring for knee joint function at the final follow-up yielded 9 excellent, 2 good and one poor. Conclusion:In treatment of tibial plateau fractures, our self-designed easily-breaking compression bone bolt plus bone plate can restore width of tibial plateau, compress fracture fragments tightly and allow for early exercise, leading to fine functional recovery of the knee joint.
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Objective:To investigate the associations of articular depression depth (ADD) and tibial plateau widening (TPW) by pre-operative CT measurement with incidence of lateral meniscal tear in patients with Schatzker type Ⅱ tibial plateau fracture.Methods:Included in this retrospective study were 131 patients who had been admitted to Emergency Center of Trauma, The Third Hospital Affiliated to Hebei Medical University from January 2016 to January 2020 for Schatzker type Ⅱtibial plateau fractures. They were 88 males and 51 females, aged from 18 to 60 years (average, 41.5 years), with 74 right and 57 left sides injured. All patients were treated with closed reduction and internal fixation assisted by bidirectional traction. Arthroscopy was used to detect the status of lateral meniscus immediately after closed reduction and internal fixation of the fracture fragments. Furthermore, patients were divided into 2 groups according to the integrity of lateral meniscus: meniscal tear group ( n=70) and tear-free group ( n=61). The 2 groups were compared in terms of age, gender, body mass index(BMI), injury side, time interval from injury to surgery, TPW and ADD. The receiver operating curve (ROC) was drafted to calculate the cut-off values of TPW and ADD in complication of lateral meniscal tear in patients with Schatzker type Ⅱ tibial plateau fracture. Results:The overall incidence of lateral meniscal tear in this cohort was 53.4% (70/131). There was no statistically significant difference in terms of age, gender, injury side, BMI or time interval from injury to surgery between the 2 groups ( P>0.05); TPW and ADD were significantly higher in the meniscal tear group than in the tear-free group ( P<0.05). To predict lateral meniscal tear in patients with Schatzker type Ⅱtibial plateau fracture, the area under ROC was 0.656 (95% CI: 0.562 to 0.750, P=0.002) for TPW and 0.709 (95% CI: 0.619 to 0.800, P<0.001) for ADD, respectively; the cut-off values of TPW and ADD were 4.3 mm and 6.1 mm. Conclusion:TPW and ADD may be effective predictors for prediction of lateral meniscal tear in patients with Schatzker type Ⅱ tibial plateau fracture.
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Objective:To understand and verify the biomechanical mechanism of tibial plateau Hoffa (coronal) fracture by simulating high-altitude falls and traffic injuries using knee joint specimens.Methods:Ten specimens of lower limb knee joint were used. They were from 6 males and 4 females, with an average age of 57.4 years (from 42 to 65 years). They were divided into 2 equal groups: one subjected to simulation of high-altitude falls (fall group) and the other to simulation of traffic injury (traffic injury group). After injury simulation, standard orthographic and lateral X-ray examinations and CT scans were performed of the knee joints in the extended position to observe whether there was a fracture, where the fracture occurred, and how the fracture line went.Results:A tibial plateau coronal fracture was successfully simulated in 6 cases, but not in the other 4 cases. The failure was attributed to femoral fractures and other types of tibial plateau fracture. In the 3 successful fractures simulated by high-altitude fall, the fracture line was located all on the posterior medial side, involving the posterior 1/3, 2/5, and 1/2 of the tibial plateau, respectively. The fracture line and the coronal plane formed angles of 21°, 19° and 12°, respectively. The fracture was not shown on X-ray film in one case which was a posterior medial fracture on CT. In the other 3 successful fractures simulated by traffic injury, the fracture line involved 1/6, 1/4 and 1/3 of the posterior tibial plateau, respectively. The angles between the fracture line and the coronal plane were 47°, 56° and 63°, respectively. One case showed no obvious fracture signs on the X-ray but a coronal fracture on CT.Conclusions:This study has confirmed for the first time that both high-altitude falls and traffic injuries can cause coronal fractures of the tibial plateau which vary significantly in the extent of involvement and morphology. X-rays are not sufficient to fully diagnose this type of fractures, suggesting that patients with a clear history of knee flexion or axial violence injury should be routinely scanned by CT to reduce risks of missed diagnosis and insufficient treatment.
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Objective:To analyze the short-term efficacy of pushing reduction via a pretibial bone tunnel for treatment of tibial plateau fracture.Methods:From March 2019 to June 2019, 9 patients were treated at Trauma Emergency Center, Third Hospital of Hebei Medical University for tibial plateau fractures by pushing reduction through a pretibial bone tunnel. They were 7 males and 2 females, aged from 26 to 63 years (average, 38 years). Involved were 5 left sides and 4 right sides. According to the Schatzker classification, there were 7 cases of type Ⅱ and 2 ones of type Ⅲ. According to the Zhang's comprehensive classification of tibial fractures, they were all type Ⅰ. The patients were operated on under general anesthesia or intraspinal anesthesia. According to the length of fracture line, a circular drill was used to establish a bone tunnel which was 1 to 2 cm away from the distal fracture line. The collapsed fracture was reduced by the bar through the bone tunnel. A bicortical autogenous iliac bone or artificial bone bar was selected for bone grafting. The plate was placed through small incisions. Arthroscopic examination was used to measure the fracture displacement. The operation time, incision length, number of fluoroscopy, intraoperative blood loss and postoperative complications were recorded.Results:For the 9 patients, operation time ranged from 40 to 60 minutes (average, 48.3 minutes), intraoperative blood loss from 35 to 60 mL (average, 46.1 mL), number of fluoroscopy from 12 to 21 times (average, 17.4 times), length of reduction incision from 1.6 to 3.0 cm (average, 2.3 cm), fracture displacement after fixation from 0 to 2.0 mm (average, 0.8 mm), and maximum mobility of the knee joint from 125° to 140° (average, 128.9°) 15 days after operation. All incisions healed well by the first intention. Fibular vein thrombosis occurred in one case after operation. There were no infections or related complications.Conclusion:The short-term efficacy of pushing reduction through a pretibial bone tunnel for treatment of tibial plateau fracture is positive, but more reliable results should be waited for when much more surgical cases are available.
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Hoffa fracture of tibial plateau is a special type of coronal fracture of tibial plateau, among which occult fracture accounts for a large proportion, resulting in missing diagnosis and delayed treatment. The current studies are all case reports, and the incidence, diagnostic protocol, injury characteristics and injury mechanism of Hoffa fracture have not been systematically studied. The commonly used classifications such as AO type, Schatzker type, three-column classification and comprehensive classification of tibial plateau cannot cover this type. In this study, a retrospective case series study was performed for the clinical data of 3 086 patients with tibial plateau fractures. There were 13 patients with Hoffa fracture of tibial plateau, and 23% of them were occult ones. The injury mechanism of this fracture was as follows: under the state of knee joint flexion, axial violence through femur concentrated on the posterior half of tibial plateau, with the knee joint in transient varus and pronation position, leading to the posteromedial coronal splitting fracture. According to the position and degree of fracture displacement involving the joint, the fracture was divided into three type: type I involving the articular surface of tibial plateau fracture less than 1/4, type II involving the articular surface of tibial plateau equal to or more than 1/4 and less than 1/2, type III involving the joint face equal to or more than 1/2. Each fracture type was divided into three subtypes, of which subtype A was non-displaced fracture, subtype B had articular surface displacement<2 mm, and subtype C had articular surface displacement≥2 mm. According to the classification characteristics, the treatment principles were proposed. The authors systematically summarized the Hoffa fracture of tibial plateau for the first time in aspects of the incidence, injury characteristics, injury mechanism, fracture classification and treatment principles, which is helpful to avoid missed diagnosis and improve treatment efficacy.
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Objective: To evaluate the effectiveness of the leverage reduction with proximal femoral nail antirotation (PFNA) ball head screw driver for difficult-reducing intertrochanteric fracture. Methods: The clinical data of 8 patients with difficult-reducing intertrochanteric fractures between July 2015 and February 2018 were retrospectively analysed. There were 3 males and 5 females, aged 66-89 years, with an average age of 76.3 years. According to Evans classification, there were 3 cases of type Ⅲ and 5 cases of type Ⅳ. The time from injury to operation was 2-8 days (mean, 3.9 days). All patients were reducted with ball head screw driver leverage through PFNA proximal incision during operation. The operation time, intraoperative blood loss, reduction time, and fluoroscopy times were recorded. Harris hip function score was used to evaluate the effectiveness at last follow-up. Results: The operation time was 52.5-83.7 minutes (mean, 68.1 minutes), the intraoperative blood loss was 49.8-96.4 mL (mean, 73.1 mL), the reduction time was 3.7-9.1 minutes (mean, 6.4 minutes), and the fluoroscopy times were 18.4-27.4 times (mean, 22.9 times). Patients were followed up 6-18 months (mean, 9.6 months). Postoperative X-ray films showed that the fracture obtained good reduction. No fracture displacement, fixation failure, and coxa vara occurred after operation. Fracture healing time was 3-6 months (mean, 4.6 months). At last follow-up, the Harris hip function score was 85-96 (mean, 91.6), with a result of excellent in 6 cases and good in 2 cases. Conclusion: The reduction of difficult-reducing intertrochanteric fracture by using ball head screw driver can obtain good reduction and reliable fixation. The method has such advantages as no more incision, and less blood loss and soft tissue injury.
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Objective To analyze the short-term outcomes of rod-shaped glass bone graft for the treatment of tibial plateau fracture.Methods From January 2019 to February 2019,4 patients with tibial plateau fracture underwent minimally invasive reduction and new glass bone graft at Trauma Emergency Center,The Third Hospital of Hebei Medical University.They were 2 men and 2 women,aged from 31 to 67 years (average,42 years).The fractures happened at 3 left sides and one right side.According to Schanzker's classification,3 cases were type Ⅱ and one case was type Ⅲ.According to Zhang's classification for tibial plateau fractures,they were all type Ⅰ.The reduction was carried out under general anesthesia by a Zhang's traction device and a self-made rod.A rod-shaped glass bone graft of appropriate size was implanted along the bone tunnel.The plate was implanted through small incisions after fluoroscopy results were satisfactory.Intraoperative arthroscopic examination was used to assess fracture displacement before wound closure.The operation time,incision length,fluoroscopic frequency for insertion of guide needle,intraoperative blood loss,and short-term postoperative complications were recorded for each patient.Results The operation time for the patients averaged 37.5 min,the total length of all incisions 7.0 cm,the fluoroscopy required for insertion of guide needle 8.8 times,and the intraoperative blood loss 40.0 ml.All incisions were healed by the first intention.Postoperative intermuscular thrombosis occurred in 2cases.No postoperative infection or related complications happened.Conclusion Rod-shaped glass bone graft can lead to positive short-term outcomes for tibial plateau fractures,but a more reliable conclusion necessitates further clinical trials with a large sample size and long-term follow-up.
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Objective To discuss the clinical effects of minimally invasive reduction and fixation with Zhang's reduction device for fractures of tibial intercondylar spine.Methods Five patients with tibial intercondylar spine fracture underwent treatment and reduction with Zhang's reduction device from December 2018 to February 2019 at Orthopedic Trauma Center,The Third Hospital of Hebei Medical University.They were 3 men and 2 women,aged from 25 to 56 years (average,43 years).The left side was affected in 2 cases and the right side in 3.By the Meyers classification,there were 2 cases of type Ⅱ and 3 ones of type Ⅲ.All the patients underwent the same surgical procedures and postoperative treatment.Their operation time,amount of bleeding,number of fluoroscopy required for insertion of guide pin,postoperative complications,fracture healing and knee joint range of motion at the last follow-up were recorded.Results The operation time for the 5 patients averaged 50.0 min,amount of bleeding 23.0 mL,and number of fluoroscopy required for insertion of guide pin 12.6 times.Their knee joint range of motion at the last follow-up ranged from 0° to 136.0°.All the incisions obtained primary union with no infection.Their hospitalization time ranged from 7 to 15 d (average,10.5 d).They obtained an average follow-up of 4.3 months (from 2 to 6months).All the fractures achieved union with no malunion,nonunion or refracture.Conclusions The minimally invasive reduction and fixation with Zhang's reduction device for fractures of tibial intercondylar spine can lead to satisfactory clinical effects.It is less invasive than open reduction and simpler than arthroscopic surgery so that it is more appropriate to be popularized in primary hospitals.However,this method has not been widely applied in clinic and more clinical trials are needed.
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Objective To evaluate the factors contributing to medial compartment knee osteoarthritis and the possible correlations between them.Methods Radiographic images were collected for analysis of 840 patients who had sought medical attention from January to July 2017 for 1,422 sides of knees varus at Department of Orthopedic Surgery,The Third Hospital of Hebei Medical University.They were aged from 17 to 87 years(average,61.0 years),involving 323 knees in males and 1,099 knees in females.The alignments and parameters of lower extremity were measured,including hip-knee-ankle angle (HKA),mechanical medial distal femoral angle (mMDFA),medial proximal tibial angle (MPTA) and joint line convergence angle (JLCA).The measurements were compared between HKA values and genders for correlation analysis.Results HKA,mMDFA,MPTA and JLCA were respectively 172.85° ± 4.27°,90.99° ± 2.59°,84.78° ± 2.82° and 2.83° ±2.33 ° for males,and 172.13 ° ± 4.63°,91.11 ° ± 2.74°,84.58 ° ± 3.30° and 3.48 ° ± 2.58 ° for females.The females had significantly smaller HKA and significantly larger JLCA than males (P ＜ 0.05),but there was no significant difference in mMDFA or MPTA between genders(P ＞ 0.05).Pearson correlation test showed that there were significant correlations between HKA and mMDFA,MPTA and JLCA (rmale1 =0.526,rmale2 =0.545,rmale3 =-0.562;rfemale1=0.547,rmale2=0.610,rmale3=-0.485;P ＜0.01).mMDFA (βmale=0.491,βfemale=0.464,P ＜0.01) and MPTA (βmale=0.487,βfemale=0.560,P ＜0.01) had significantly positive influences on HKA;the influence of JLCA was negative (βmale =-0.463,βfemale =-0.450,P ＜0.01).Conclusions Femoral mechanical axis varus,increased JLCA and collapse of medial tibial plateau all significantly contribute to the varus gonarthrosis.The effects of mMDFA,MPTA and JLCA on HKA may be almost the same.
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Objective To compare the biomechanical characteristics of medial and lateral locking plates for Schatzker typeⅥfractures of tibial plateau by finite element analysis. Methods A 38 year-old male volunteer was enrolled for CT scan of his lower limbs. His CT images of the left tibial plateau were used for 3D reconstruction of a model of Schatzker type Ⅵ fracture by NX 9.0 software. After the boundary con-ditions were set, a 500 N load was applied to the tibial plateau to simulate the stress on a single leg when an adult weighing 60 kg walked. The displacement and stress on plate and screws were analyzed by Abaqus software. Results The ultimate stress on the model fixated with a medial locking plate was 81.7 MPa, located at the proximal tibiofibular joint surface. The ultimate stress on the model fixated with a lateral locking plate was 487.4 MPa, located at the junction of plate and screws. The ultimate stress on the fibula was much larger in the model fixated with a medial locking plate than in the model fixated with a lateral locking plate. The ultimate displacement was smaller and more homogeneous in the model fixated with a medial locking plate (1.15 mm) than in the model fixated with a lateral locking plate (3.44 mm).Conclusion The Schatzker type Ⅵ fractures of tibial plateau should be fixated with a medial locking plate because it has more biomechanical advantages than a lateral locking plate.
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Objective To investigate the effect of homeopathic reduction technique in treatment of irreducible variant femoral neck fractures.Methods A retrospective case control study was performed for 91 cases of irreducible variant femoral neck fractures surgically treated from January 2011 to January 2014.Forty-seven cases [31 males,16 females;23-61 years,mean 40.6 years] were assigned to homeopathic reduction treatment (study group) and 44 [30 males,14 females;28-63 years,mean 43.1 years] were assigned to closed reduction and open reduction (control group).All fractures were Garden type Ⅳ.All cases were stabilized with three cannulated screws (6.5 mm in diameter).Operation time,intraoperative blood loss,Garden index for reduction quality,bone healing,complications like femoral head necrosis and Harris hip score were evaluated.Results Operation time and blood loss in study group [(41.2 ± 7.5) min,(37.3 ± 9.5) ml] were significantly lower than those in control group [(105.0 ± 15.7) min,(269.6 ± 50.6) ml] (P ＜ 0.05).Garden index was Grade Ⅰ 44 cases and Grade Ⅱ three in study group compared to Grade Ⅰ 20 and Grade Ⅱ three in control group (P ＜ 0.05).Incidence of femoral head necrosis had no significant differences between study group (four cases) and control group (10 cases) (P ＞ 0.05).Nonunion was not observed in study group,while there were eight cases of nonunion in control group (P ＜ 0.05).According to the Harris score,the excellent rate in study group was 91％ (39 excellent,four good,four fair) versus 66％ (21 excellent,eight good,15 fair) in control group (P ＜ 0.05).Conclusion Compared to closed reduction and open reduction,homeopathic reduction technique in treatment of femoral neck fractures is associated with shortened operation time,reduced blood loss,improved reduction quality and lowered incidence of necrosis and nonunion.
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BACKGROUND:Three-dimensional (3D) printing technology exhibits a broad future in the orthopedics,especially exhibiting good guidance and auxiliary in the treatment of tibial plateau fractures.However,the related researches are few,and there is a lack of evidence-based medicine to confirm its application values.OBJECTIVE:To compare the efficacy of 3D printing-assisted surgery and traditional surgery in the treatment of tibial plateau fractures through a meta-analysis.ME=THODS:MEDLINE,Cochrane library,Embase,CBM,CNKI and WanFang databases were searched by computer and the relevant literatures were retrieved manually,to collect the controlled trials concerning the efficacy of 3D printing-assisted surgery versus traditional surgery for tibial plateau fractures.Methodology quality of the trials was assessed critically and relative data were extracted,followed by analysis on Stata 11.0 (Stata Corporation,College Station,TX) software.RESULTS AND CONCLUSION:(1) Seven controlled trials involving 362 patients were included.(2) Meta-analysis results showed that the 3D printing-assisted surgery had shorter operation time (SMD=-2.411,95％C/=-2.718-2.104,P=-0.00) and less intraoperative blood loss (SMD=-1.579,95％C/=-1.842--1.316,P=-0.00) than those in the traditional surgery.The excellent and good rate in Rasmussen and Hospital for Special Surgery knee scores showed no significant differences between two growps (P ＞ 0.05).(3) To conclude,compared with the traditional surgery,the 3D printing-assisted surgery can significantly shorten the operation time and reduce the intraoperative blood loss in the treatment of tibial plateau fractures.
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Objective To evaluate the effect of different degrees of pubic symphysis diastasis on the stress distribution of posterior pelvic ring. Methods Eight embalmed pelvis and articulated proximal 1/3 of the femurs were harvested for this study. The samples were positioned as both legs standing straight and loaded to 600 N on the on the CSS-44020 biomechanical machine. The strain gages were adhered to 38 sites distributed symmetrically on the two sides of sacroiliac joint, anterior sacrum and posterior ilium. The strain gages were connected to WS3811 digital strainometer to record strain changes of the intact pelvic ring and at 1,2, 2.5 cm of pubic symphysis diastasis. Results Elastic changes occurred in the cortical bone of the pelvis under 600 N load. The symmetrical sites had similar strain changes without significant difference in the intact pelvic ring and at 1,2, 2.5 cm of pubic symphysis diastasis ( P ＞0.05 ). The sites with more strain changes were distributed on the iliofemoral arch in the intact pelvis.The strain changes were increased significantly frona the posterolateral sites to the iliofemoral arch. But the strain changes on the iliofemoral arch were decreased significantly during pubic symphysis diastasis.Conclusion The conduction of vertical load runs along the sacrofemoral arch in the intact pelvic ring and redistributes posterolaterally during pubic symphysis diastasis.
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Objective To investigate the epidemiological features of 937 patients wounded in China Wenchuan earthquake. Methods An analysis was done on 937 patients treated in the city of Deyang in aspects fo their gender,age,injury causes,wound sites,complications and misdiagnosis.Results There were more wounded females than males,with ratio of male to female of 1:1.12.The main injury causes were crush injury and falling injury.The most frequent injury sites include head,chest,ankle and foot,tibia and fibula,spine and hip.The rate of misdiagnosis was as high as 15.5%,mainly brain injuries and chest iniuries. Conclusion The main causes are crush iniury and falling in-jury.Lower limb fractures account for the most.While close brain and thoracic injuries are likely to be misdiagnosed.