Pulmonary thromboembolism after distal ulna and radius fractures surgery: A case report and a literature review

BACKGROUND Pulmonary thromboembolism(PTE)is a serious postoperative complication that can occur after a fracture.Generally,PTE is caused by the falling off of lower extremity deep vein thrombosis(LEDVT)after lower limb fracture surgery.LEDVT and PTE after upper extremity fracture surgery are very rare.PTE is one of the most common clinical causes of sudden death.Venous thromboembolism includes PTE and DVT.We experienced one case of LEDVT and PTE after distal ulna and radius fracture surgery.The purpose of our report is to raise awareness for orthopedic surgeons that PTE can occur after distal ulna and radius fracture surgery,and patients with high risk factors should be considered for prevention and treatment of thrombosis in a timely manner.CASE SUMMARY We report a 51-year-old Chinese male who had severe fractures of the left distal ulna,radius and little finger after a motorcycle accident.The patient underwent external fixation,open reduction and internal fixation.On the third post-operative day,computed tomographic pulmonary angiography showed PTE.Doppler ultrasonography showed thrombus formation in the bilateral posterior tibial veins.After a period of anticoagulation therapy,on the 25th d after the PTE,computed tomographic pulmonary angiography showed that thrombus in both sides of the pulmonary artery disappeared.Furthermore,about 4 mo after the PTE,thrombosis in the deep veins of the lower limbs disappeared.About 1 year after the surgery,X-rays showed good fracture healing,and the function of the wrist joint recovered well.CONCLUSION Though rare,PTE can occur after distal ulna and radius fracture surgery and patients with high risk factors should be considered for prevention and treatment of thrombosis in a timely manner.

Low risk of postoperative ulnar nerve affection in surgically treated distal humeral fractures when the nerve is released in situ

BACKGROUND Adult distal humeral fractures(DHF)comprise 2%-5%of all fractures and 30%of all elbow fractures.Treatment of DHF may be technically demanding due to fracture complexity and proximity of neurovascular structures.Open reduction and internal fixation(ORIF)are often the treatment of choice,but arthroplasty is considered in case of severe comminution or in elderly patients with poor bone quality.Ulnar nerve affection following surgical treatment of distal humerus fractures is a well-recognized complication.AIM To report the risk of ulnar nerve affection after surgery for acute DHFs.METHODS We retrospectively identified 239 consecutive adult patients with acute DHFs who underwent surgery with ORIF,elbow hemiarthroplasty(EHA)or total elbow arthroplasty(TEA)between January 2011 and December 2019.In all cases,the ulnar nerve was released in situ without anterior transposition.We used our institutional database to review patients’medical records for demographics,fracture morphology,type of surgery and ulnar nerve affection immediately;records were reviewed after surgery and at 2 wk and 12 wk of routine clinical outpatient follow-up.Twenty-nine percent patients were excluded due to pre-or postoperative conditions.Final follow-up examination was a telephone interview in which ulnar nerve affection was reported according to the McGowen Classification Score.A total of 210 patients were eligible for interview,but 13 patients declined participation and 17 patients failed to respond.Thus,180 patients were included.RESULTS Mean age at surgery was 64 years(range 18-88 years);121(67.3%)patients were women;59(32.7%)were men.According to the AO/OTA classification system,we recorded 47 patients with type A3,55 patients with type B and 78 patients with type C fractures.According to the McGowen Classification Score,mild ulnar nerve affection was reported in nine patients;severe affection,in two.A total of 69 patients were treated with ORIF of whom three had mild temporary ulnar nerve affection and one had severe ulnar nerve affection.In all,111 patients were treated with arthroplasty(67 EHA,44 TEA)of whom seven had mild ulnar nerve affection and one had severe persistent ulnar nerve affection.No further treatment was provided.CONCLUSION The risk of ulnar nerve affection after surgical treatment for acute DHF is low when the ulnar nerve is released in situ without nerve transposition,independently of the treatment provided.

Diagnosis and Treatment of a Case of Radius and Ulna Fracture in Dog

60% of a dog's body weight is supported by its fore limbs, while the hind limbs mainly play the role of power, so the probability of dog's radius and ulna fracture is greatly increased. This paper mainly introduced the diagnosis and treatment of a case of radius and ulna fracture in dog, with an attempt to provide reference for clinical practice.

Squamous Cell Carcinoma of the Oropharynx Presenting with Distant Metastasis to the Ulna

Squamous cell carcinomas are the commonest malignancies of the head and neck. Metastases from stage III and stage IV tumors occur most commonly in the cervical lymph nodes. The incidence of distant metastases occurring from such advanced tumors is anywhere between 10% and 40%. Distant metastases occur most commonly to the lungs followed by the bone and liver. The bone metastasis occurs commonly in the axial skeleton. We report a rather unusual case of squamous cell carcinomas from the Head and Neck region in a 77-year-old male metastasizing to the ulna. This case is even more interesting because the presenting symptom was a pathological fracture of the ulna for which he had reported to the orthopedic department. The immunohistochemistry of the metastatic tumor had shown an unmistakable squamous cell carcinoma with positive cytokeratin elements within the tumor. He referred to the ENT department where he was diagnosed with T2N0M1 squamous cell carcinoma of the oropharynx. The patient was treated with internal fixation and bone cementing for the metastatic lesion, and primarily treated with chemoradiation.

Health economics for intra-capsular hip fractures undertaking fixation

BACKGROUND Hip fracture is a common musculoskeletal injury in the elderly requiring surgery worldwide.The operative mainstay of intra-capsular hip fractures is arthroplasty with a smaller proportion for fixation.AIM To determine the most beneficial method of fixation for patients with intracapsular hip fractures.METHODS A registered audit from 2012-2018 was conducted on all intra-capsular hip fractures treated with 2 commonly used fixation methods.Patient notes,electronic records and clinical codes for cost benefit were evaluated.A validated quality of life measure was collected at least 1 year after surgery.RESULTS A total of 83 patients were identified with intra-capsular fractures undergoing fixation during the retrospective period.There were 47 cannulated cancellous screw and 36 sliding hip screw fixations with the case mix comparable for age,gender,co-morbidities and fracture configuration.There was no significant difference in blood loss,tip apex distance,radiation exposure,length of stay,radiological union time,collapse,avascular necrosis or re-operation between fixation methods.Logistic regression analysis demonstrated displaced intracapsular hip fractures correlated significantly with an undesirable outcome conferring a relative odds ratio of 7.25.There were 9(19%)and 4(11%)patients respectively,who required re-operation.There was no significant difference in health resource group tariff and implant cost with comparable EQ-5D and visual CONCLUSION No significant advantage was identified with differing fixation type,but irrespective there were a high number of patients requiring re-operation.This was predicted by initial fracture displacement and patient age.Arthroplasty may need to be carefully considered for health economics and patient benefit.

Arthroscopic M-shaped suture fixation for tibia avulsion fracture of posterior cruciate ligament:A modified technique and case series

BACKGROUND Tibial avulsion fractures of the posterior cruciate ligament(PCL)are challenging to treat and compromise knee stability and function.Traditional open surgery often requires extensive soft tissue dissection,which may increase the risk of morbidity.In response to these concerns,arthroscopic techniques have been evolving.The aim of this study was to introduce a modified arthroscopic tech-nique utilizing an M-shaped suture fixation method for the treatment of tibial avulsion fractures of the PCL and to evaluate its outcomes through a case series.AIM To evaluate the effects of arthroscopic M-shaped suture fixation on treating tibia avulsion fractures of the PCL.METHODS We developed a modified arthroscopic M-shaped suture fixation technique for tibia avulsion fractures of the PCL.This case series included 18 patients who underwent the procedure between January 2021 and December 2022.The patients were assessed for range of motion(ROM),Lysholm score and International knee documentation committee(IKDC)score.Postoperative complications were also recorded.RESULTS The patients were followed for a mean of 13.83±2.33 months.All patients showed radiographic union.At the final follow-up,all patients had full ROM and a negative posterior drawer test.The mean Lysholm score significantly improved from 45.28±8.92 preoperatively to 91.83±4.18 at the final follow-up(P<0.001),and the mean IKDC score improved from 41.98±6.06 preoperatively to 90.89±5.32 at the final follow-up(P<0.001).CONCLUSION The modified arthroscopic M-shaped suture fixation technique is a reliable and effective treatment for tibia avulsion fractures of the PCL,with excellent fracture healing and functional recovery.

Percutaneous Fixation as an Option for Traumatic Neurologically Intact Thoracolumbar Vertebral Fractures

Background: The most frequent spinal fracture is the thoracolumbar fracture. Minimally invasive percutaneous fixation of cases having thoracolumbar vertebral fractures without neurological impairments has remained controversial. The advantages of minimally invasive percutaneous fixation are decreasing muscle and soft tissue injury, decreasing blood loss and infection rate, in addition to shortening hospital stay and recovery times. In comparison to the open technique, percutaneous fixation is adequate for treating thoracolumbar (TL) fractures without causing neurological impairments & with satisfactory outcomes in terms of kyphosis decline. Elevated radiation exposure to the surgeon &the patient, lack of decompression and fusion via bone graft, & a steep learning curve are all disadvantages of percutaneous fixation of vertebral fractures. Methods: This study was retrospectively conducted on forty-eight patients, age ranging from 16 to 65 years old, with a thoracolumbar (TL) fracture without causing neurological impairments who were meeting the eligibility criteria for fixation in the period from July 2019 to January 2024. Results: We included the forty-eight patients who met the inclusion criteria (34 males and 14 females) their ages ranged from 16 to 65 years. The most common pathology was L1 fracture in 38 patients. No major complications were experienced, only wound infection in five patients which was treated efficiently with repeated dressings and broad-spectrum antibiotics. Four patients experienced misdirected screws, only in one patient the screw encroach into the spinal canal with no deficit experienced, while the other three showed minimally laterally deviated screws. Conclusion: The advantages of percutaneous pedicle screw fixation in thoracolumbar fractures through preservation of posterior musculature, are less blood loss, shorter operative time, lower infection risk, less post-operative pain, shorter rehabilitation time as well as a shorter hospital stay. Limitations of percutaneous fixation include the inability to achieve direct spinal canal decompression and, not having the option to perform a fusion and also requiring a learning curve to master the anatomy and technique.

Clinical Outcome of Internal Fixation and Fusion in the Treatment of Spinal Fractures by Paraspinal Muscular Space Approach

Objective:To explore the clinical effect of internal fixation and fusion with the paraspinal muscle gap approach in the treatment of spinal fracture patients.Methods:104 spinal fracture patients admitted to Central Hospital of TCM from October 2022 to April 2024 were selected as the study subjects and were randomly divided into the control group(n=52)and the observation group(n=52)according to the random number table method.The control group was treated with the conventional approach of internal fixation surgery,and the observation group was treated with the paraspinal muscular interspace approach of internal fixation fusion.The two groups’general data,surgical indexes,pain,lumbar spine function,and postoperative complications were observed.Results:The baseline data of the two groups of patients were not statistically significant(all P>0.05)while the intraoperative bleeding,the first postoperative time getting up from bed,and the length of hospital stay of the patients in the observation group were shorter than that of the control group(all P=0.000<0.001),and the duration of the operation was longer than that of the control group(t=2.644,P=0.010<0.05);at 3 months postoperatively,the VAS scores of the patients in the observation group were significantly lower than those in the control group(t=10.768,P=0.000<0.001),and the JOA score was higher than that of the control group(t=6.498,P=0.000<0.001);the total complication rate of patients in the observation group(3/5.77%)was significantly lower than that of the control group(12/23.08%)(χ^(2)=6.310,P=0.012<0.05).Conclusion:In the treatment of spinal fracture patients,compared with the conventional approach to internal fixation surgery,the paraspinal muscular gap approach to internal fixation and fusion treatment is less traumatic,postoperative lumbar spine function recovery is faster,and can reduce the incidence of postoperative complications.

Clinical Effectiveness of the Plate Screw Internal Fixation Technique in the Treatment of Patients with Traumatic Fractures of Long Bones in the Lower Extremities

Objective: To investigate the effectiveness of the plate screw internal fixation technique on the clinical outcomes of patients with traumatic fractures of long bones in the lower extremities. Methods: From January 2022 to December 2023, 70 patients with traumatic fractures of long bones in the lower extremities were admitted to the hospital and randomly divided into two groups: the control group and the observation group, each consisting of 35 cases. The control group underwent traditional closed interlocking intramedullary nailing, while the observation group received internal fixation with steel plates and screws. Relevant surgical indicators, treatment effectiveness, and postoperative complication rates were compared between the two groups. Results: The observation group exhibited significantly short surgical duration (80.65 ± 5.01 vs. 88.36 ± 5.26 minutes), fracture healing time (13.27 ± 0.32 vs. 15.52 ± 0.48 weeks), and hospitalization days (10.49 ± 1.13 vs. 16.57 ± 1.15 days) compared to the control group (P = 0.000). The effective treatment rate was significantly higher in the observation group (29/82.86%) than in the control group (21/60.00%), with a significant difference observed (χ2 = 4.480, P = 0.034). Additionally, the complication rate in the observation group (2/5.71%) was significantly lower than that in the control group (8/22.86%), with a correlated difference (χ2 = 4.200, P = 0.040). Conclusion: The plate screw internal fixation technique demonstrates significant clinical efficacy in treating traumatic fractures of long bones in the lower extremities. It improves the healing rate, reduces complications, and represents a safe and effective treatment strategy worthy of widespread use and application.

Selection of internal fixation method for femoral intertrochanteric fractures using a finite element method

BACKGROUND Failure to fix unstable intertrochanteric fractures impairs return to daily activities.AIM To simulate five different internal fixation methods for unstable proximal femoral fractures.METHODS A three-dimensional model of the femur was established from sectional computed tomography images,and an internal fixation model was established.Finite element analysis of the femur model was established,and three intertrochanteric fracture models,medial defect,lateral defect,and medial-lateral defects,were simulated.Displacement and stress distribution after fixation with a proximal femoral anti-rotation intramedullary nail(PFNA),integrated dual-screw fixation(ITN),PFNA+wire,PFNA+plate,and PFNA+wire+plate were compared during daily activities.RESULTS The maximum displacement and stress of PFNA and ITN were 3.51 mm/473 MPa and 2.80 mm/588 MPa for medial defects;2.55 mm/288 MPa and 2.10 mm/307 MPa for lateral defects;and 3.84 mm/653 MPa and 3.44 mm/641 MPa for mediallateral defects,respectively.For medial-lateral defects,reconstructing the medial side alone changed the maximum displacement and stress to 2.79 mm/515 MPa;reconstructing the lateral side changed them to 3.72 mm/608 MPa,when both sides were reconstructed,they changed to 2.42 mm/309 MPa.CONCLUSION For medial defects,intramedullary fixation would allow early low-intensity rehabilitation exercise,and ITN rather than PFNA reduces the risk of varus and cut-out;for lateral wall defects or weakness,intram-edullary fixation allows higher-intensity rehabilitation exercise,and ITN reduces the risk of varus.For both medial and lateral defects,intramedullary fixation alone will not allow early functional exercise,but locating lateral or medial reconstruction will.For defects in both the inner and outer sides,if reconstruction cannot be completed,ITN is more stable.

Biomechanical analysis of fracture fixation with external fixator in vivo

Objective ：To investigate the different ways of measuring the main axial strain during treatment with an external fixator and to find the suitable compression loaded by the external fixator at an early stage. Methods. Eighteen healthy big-ear rabbits were randomly divided into two groups according to different measuring methods： Group A and Group B. In Group A, a strain gauge was affixed to the external tibiai cortex with 502 glue, and in Group B, a bone cement-coated strain gauge was installed on the internal tibial cortex. Groups A and B were divided into two subgroups A1, A2 and B1, B2, respectively, according to the pressure of haft of and the same as the body weight. A Z-shaped left mid-shaft tibiai osteotomy was performed and fixed by an external fixator. Results： The scaler curves of Group A changed dramatically during the early stage. The trendlines of the internal and external cortex went consistently after reaching the stable stage while the latter strain value was higher than the former. The time for Group B reaching the stable stage was short, but its absolute strain value was less than that of Group A. Before they were pressed to the stable stage, the declined speed of Subgroup A1 was more slowly than that of Subgroup A2 while the results of Subgroups B1 and B2 were same. Group A had an ascending trend after it declined while Group B didn＇t have. After they reached the stable stage, both Subgroups A1 and A2 had a declining trend while Subgroup A2 was more quickly than Subgroup A1, Subgroup B1 was kept at a definite level while Subgroup B2 fluctuated. Conclusions： The axial strain under external fixator can be measured by bone cement coated-strain gauge in vivo. The data may suggest that half of the body weight load was suitable for external fixator.

Open reduction and Herbert screw fixation of Pipkin type IV femoral head fracture in an adolescent:A case report

BACKGROUND Femoral head fracture is extremely rare in children.This may be the youngest patient with femoral head fracture ever reported in the literature.There are few pediatric studies that focus on cases treated with open reduction via the modified Hardinge approach.CASE SUMMARY A 14-year-old female adolescent suffered a serious traffic accident when she was sitting on the back seat of a motorcycle.A pelvic radiograph and computed tomography revealed a proximal femoral fracture and slight acetabular rim fracture.This was diagnosed as a Pipkin type IV femoral head fracture.An open reduction and Herbert screw fixation was performed via a modified Hardinge approach.After 1-year follow-up,the patient could walk without aid and participate in physical activities.The X-ray results showed that the fractures healed well with no evidence of complications.CONCLUSION Open reduction and Herbert screw fixation is an available therapy to treat Pipkin type IV femoral head fractures in children.

Tubercular arthritis of the elbow joint following olecranon fracture fixation and the role of TGF-beta in its pathogenesis

Tuberculosis （TB） occurring after a closed bone fracture in the patient with no history of TB and no evidence of TB infection at the time of initial fracture is a rare entity. We report one such case of a 48-year-old female, who presented in the emergency department with an olecranon fracture which was open reduced and inter- nally fixed with tension band wiring. Patient presented in the outpatient department with serosanguineous discharge at 3 weeks after surgery. The discharge was sent for culture and sensitivity tests, and the patient was managed by anti- biotics and daily dressings. There was wound dehiscence and the underlying implant was exposed, which was removed at 12 weeks after surgery. Repeat debridements and dressings continued for 6 months, but the discharge from the wound site continued. X-rays of the elbow performed at 6 months raised the suspicion of TB, which was confirmed by Ziel-Neelsen staining and histopathological examination of the debrided tissue. Following the confirmation, patient was put on antitubercular drugs. The patient responded to anti- tubercular drug therapy （ATT）, the purulent discharge from the wound ceased, and eventually the wound healed after 2 months of starting ATT.

DEGRADATION AND PROCESSING OF PLA AND ITS APPLICATION IN FIXATION OF BONE FRACTURE

PLA is presently considered as the most attractive compound for temporarytherapeutic application in the biomedical field. In this paper we give an overview of thepresent knowledge on the degradation behavior,processing technology of PLA and itsapplication in the fixation of bone fracture.

Management of geriatric acetabular fractures:Contemporary treatment strategies

Acetabular fractures in the geriatric population are typically low-energy fractures resulting from a fall from standing height.Compromised bone quality in the elderly,as well as this population’s concomitant medical comorbidities,render the management of such fractures challenging and controversial.Non-operative management remains the mainstay of treatment,although such a choice is associated with numerous and serious complications related to both the hip joint as well as the general condition of the patient.On the other hand,operatively treating acetabular fractures(e.g.,with osteosynthesis or total hip arthroplasty)is gaining popularity.Osteosynthesis can be performed with open reduction and internal fixation or with minimally invasive techniques.Total hip arthroplasty could be performed either in the acute phase combined with osteosynthesis or as a delayed procedure after a period of non-operative management or after failed osteosynthesis of the acetabulum.Regardless of the implemented treatment,orthogeriatric co-management is considered extremely crucial,and it is currently one of the pillars of a successful outcome after an acetabular fracture.

Clinical outcomes of triceps reflecting anconeus pedicle and olecranon osteotomy approach for distal humerus intercondylar fractures

BACKGROUND The preferred treatment for distal humeral intercondylar fractures is open reduction and internal fixation.While there is consensus about the posterior approach,several posterior approaches have been developed.It is debatable as to which approach is best.AIM To compare triceps reflecting anconeus pedicle(TRAP)and olecranon osteotomy approaches for internal fixation of distal humeral intercondylar fracture.METHODS In total,40 cases of Arbeitsgemeinschaft für Osteosynthesefragen/Association of the Study of Internal Fixation type C,closed,and Gustilo type I intercondylar humeral fractures were included.Patients ranged in age from 18 years to 70 years.The patients were randomized into two groups:TRAP group and olecranon osteotomy group,with 20 cases in each.All were followed up at 6 wk,3 months,6 months,and 12 months.Functional outcomes were measured in terms of flexion-extension arc,Disabilities of Arm,Shoulder and Hand score,and Mayo Elbow Performance Score.RESULTS The mean age was 43.2 years in the TRAP group and 37.5 years in the olecranon osteotomy group.The mean operative time and mean duration of hospital stay in the TRAP group were significantly higher than in the olecranon osteotomy group(119.5 vs 111.5 min and 9.85 vs 5.45 d,respectively).The mean arc of flexion-extension,Disabilities of Arm,Shoulder and Hand score,and Mayo Elbow Performance Score were comparable without any significant difference in the groups at the 12-month follow-up(107.0 vs 106.2,18.3 vs 15.7,and 84.2 vs 86.2,respectively).Ulnar paresthesia and superficial infections were comparable in both groups(2 cases vs 3 cases and 3 cases vs 2 cases,respectively).Hardware prominence was significantly higher in the olecranon osteotomy group,mostly due to tension band wiring.CONCLUSION Both approaches were equivalent,but there is a need for further study including higher numbers of subjects and longer study duration to prove the benefits of one approach over the other.

Ankle fracture configuration following treatment with and without arthroscopic-assisted reduction and fixation

AIM: To report ankle fracture configurations and bone quality following arthroscopic-assisted reduction and internal-fixation(ARIF) or open reduction and internalfixation(ORIF). METHODS: The patients of ARIF(n = 16) or ORIF(n = 29) to treat unstable ankle fracture between 2006 and 2014 were reviewed retrospectively. Baseline data, including age, sex, type of injury, immediate postoperative fracture configuration(assessed on X-rays and graded by widest gap and largest step-off of any intraarticular site), bone quality [assessed with bone mineral density(BMD) testing] and arthritic changes on X-rays following surgical treatments were recorded for each group.RESULTS: Immediate-postoperative fracture configurations did not differ significantly between the ARIF and ORIF groups. There were anatomic alignments as 8(50%) and 8(27.6%) patients in ARIF and ORIF groups(P = 0.539) respectively. There were acceptable alignments as 12(75%) and 17(58.6%) patients in ARIF and ORIF groups(P = 0.341) respectively. The arthritic changes in follow-up period as at least 16 wk following the surgeries were shown as 6(75%) and 10(83.3%) patients in ARIF and ORIF groups(P = 0.300) respectively. Significantly more BMD tests were performed in patients aged > 60 years(P < 0.001), ARIF patients(P = 0.021), and female patients(P = 0.029). There was no significant difference in BMD test t scores between the two groups. CONCLUSION: Ankle fracture configurations following surgeries are similar between ARIF and ORIF groups, suggesting that ARIF is not superior to ORIF in treatment of unstable ankle fractures.

Lumbopelvic Fixation and Sacral Decompression for U-shaped Sacral Fractures： Surgical Management and Early Outcome

U-shaped sacral fractures are rare and often difficult to diagnose primarily due to the difficulty in obtaining adequate imaging and the severe associated injuries. These fractures are highly unstable and frequently cause neurological deficits. The majority of surgeons have limited experience in management of U-shaped sacral fractures. No standard treatment protocol for U-shaped sacral fractures has been available till now. This study aimed to examine the management of U-shaped sacral fractures and the early outcomes. Clinical data of 15 consecutive patients with U-shaped sacral fracture who were admitted to our trauma center between 2009 and 2014 were retrospectively analyzed. Demographics, fracture classification, mechanism of injury and operative treatment and deformity angle were assessed. All the patients were treated with lumbopelvic fixation or （and） sacral decompression. EQ-5d score was applied to evaluate the patients＇ quality of life. Of the 15 consecutive patients with U-shaped sacral fracture, the mean age was 28.8 years （range： 15-55 years） at the time of injury. There were 6 females and 9 males. The mean follow- up time was 22.7 months （range： 9-47 months） and mean full weight-bearing time was 9.9 weeks （range： 8-14 weeks）. Ten patients received lumbopelvic fixation and sacral decompression, one lombosacral fixation, and 4 merely sacral decompression due to delayed diagnosis or surgery. The post-operation deformity angle （mean 27.87°, and range： 8°-90°） of the sacrum was smaller than that pre-operation （mean 35.67; range： 15-90） with no significance difference noted. At the latest follow-up, all patients obtained neurological recovery with different extents. Visual analogue score （VAS） was reduced from preoperative 7.07 （range： 5-9） to postoperetive 1.93 （range： 1-3）. All patients could walk without any aid after treatment. Eight patients were able to care for themselves and undertook some daily activities. Five patients had returned to work full time. In conclusion, lumbopelvic fixation is an effective method for stabilization of U-shaped sacral fractures with fewer complications developed. Effective reduction and firm fixation are the prerequisite of early mobilization and neurological recovery. Sacral decompression effectively promotes neurological recovery even in patients with old U-shaped sacral fractures.

A Biomechanical Comparison of Conventional versus an Anatomic Plate and Compression Bolts for Fixation of Intra-articular Calcaneal Fractures

The purpose of this study was to compare the biomechanical stability obtained by using our technique featured an anatomical plate and compression bolts versus that of the conventional anatomic plate and cancellous screws in the fixation of intraarticular calcaneal fractures.Eighteen fresh frozen lower limbs of cadavers were used to create a reproductive Sanders type-Ⅲ calcaneal fracture model by using osteotomy.The calcaneus fractures were randomly selected to be fixed either using our anatomical plate and compression bolts or conventional anatomic plate and cancellous screws.Reduction of fracture was evaluated through X radiographs.Each calcaneus was successively loaded at a frequency of 1 Hz for 1000 cycles through the talus using an increasing axial force 20 N to 200 N and 20 N to 700 N,representing the partial weight bearing and full weight bearing,respectively,and then the specimens were loaded to failure.Data extracted from the mechanical testing machine were recorded and used to test for difference in the results with the Wilcoxon signed rank test.No significant difference was found between our fixation technique and conventional technique in displacement during 20-200 N cyclic loading(P=0.06),while the anatomical plate and compression bolts showed a great lower irreversible deformation during 20-700 N cyclic loading(P=0.008).The load achieved at loss of fixation of the constructs for the two groups had significant difference:anatomic plate and compression bolts at 3839.6±152.4 N and anatomic plate and cancellous screws at 3087.3±58.9 N(P=0.008).There was no significant difference between the ultimate displacements.Our technique featured anatomical plate and compression bolts for calcaneus fracture fixation was demonstrated to provide biomechanical stability as good as or better than the conventional anatomic plate and cancellous screws under the axial loading.The study supports the mechanical viability of using our plate and compression bolts for the fixation of calcaneal fracture.

Pedicle Screw Fixation with Kyphoplasty Decreases the Fracture Risk of the Treated and Adjacent Non-treated Vertebral Bodies:a Finite Element Analysis

Adjacent vertebral fractures are common in patients with osteoporotic vertebral compression fractures（OVCFs） after kyphoplasty.This finite element study was to examine whether short segment pedicle screw fixation（PSF） with kyphoplasty may decrease the fracture risk of the treated and adjacent non-treated vertebrae after kyphoplasty for OVCFs.By simulating cement augmentation with or without short segment pedicle screw fixation（PSF）,two tridimensional,anatomically detailed finite element models of the T10–L2 functional spinal junction were developed.The insertion of pedicle screws into the intact vertebra apparently decreased the stress distribution of the treated vertebra in vertical compression and other load situations.The stress distribution in the bone structures of the intact vertebra adjacent to the intact-screwed vertebra was much less than that in the one adjacent to the treated vertebra.The insertion of pedicle screws into the intact vertebra greatly decreased the maximum displacement of the cortical bones and cancellous bones of the vertebrae.Our results indicated that short segment PSF with kyphoplasty may decrease the fracture risk of the treated and adjacent non-treated vertebrae in the management of OVCFs.