Typical Fracture Patterns Research Articles

Intra-articular distal radius fractures involving the distal radioulnar joint (DRUJ): three dimensional computed tomography-based classification

PurposeThe purpose of this study was to analyze fracture patterns and the magnitude of displacement in the distal radioulnar joint (DRUJ), by three-dimensional (3D) computed tomography (CT), for distal radius fractures with intra-articular displacement of the radiocarpal joint. MethodsWe reconstructed 3D images for 72 consecutive patients with displaced intra-articular distal radius fracture on the basis of fine-cut axial CT data. The fracture patterns involving the DRUJ were classified on the basis of the location and direction of fracture lines, and the extent of fracture comminution. We measured the maximum spatial distance of the gap and the step between the fragments in each 3D image, and the magnitudes of displacement between the groups were compared by analysis of variance followed by post-hoc analysis by use of Tukey’s test. ResultsSixty wrists had a fracture involving the DRUJ. We classified the 60 wrists into 3 types of fracture pattern. Type 1 was a transverse fracture with minimum displacement. Type 2, in which fracture lines extended into the distal margin of the sigmoid notch, was the most common longitudinal fracture. Type 3 was a fracture with multiple fragments. The step and gap in Type 3 was significantly larger than that in the other types. ConclusionsEighty-three percent of intra-articular distal radius fractures had DRUJ involvement, and 28% of the wrists had multiple fragments. For Type 3 fractures with dorsal or proximal comminution displacement was significantly larger than for simple Type 1 and 2 fractures. Surgical intervention for the DRUJ fragment may be beneficial when there is remarkable intra-articular displacement.

Imaging of maxillofacial and skull base trauma

•. Brain and cervical spine imaging is often appropriate in patients with suspected high-energy facial or skull base fractures. •. A systematic approach to plain radiograph analysis is required to screen patients for significant midfacial fractures and CT is not required for uncomplicated fractures. •. CT rather than plain films is the imaging of choice for suspected craniofacial or skull base fractures. •. Ultrasound, MRI, angiography and other radiological techniques have a role in the evaluation of soft tissue complications of facial and skull base trauma. •. It is useful to approach facial and skull base fractures using an anatomical framework comprising mandibular, central/lateral midface, orbital, craniofacial, middle skull base and temporal bone fractures. •. Neurovascular damage and dural injury leading to cerebrospinal fluid leak and meningitis are key complications of skull base fractures. We review the imaging techniques and protocols used to investigate facial and skull base trauma. Fractures will be classified as mandibular, central midface, lateral midface, orbital, craniofacial, middle skull base and temporal bone fractures. Typical fracture patterns, clinically important features and anticipated soft tissue complications will be emphasised and illustrated.

Central Versus Eccentric Internal Fixation of Acute Scaphoid Fractures

To accurately calculate the cross-sectional area of typical scaphoid fracture patterns and compare the amount of fracture surface area available for healing when a screw was positioned in the center of the scaphoid (central) versus perpendicular (eccentric) to the fracture plane. We employed a laser scanning technique to create 3-dimensional models of the scaphoid and permit the precise calculation of area along any cross-sectional cut of the bone. We computed approximate bone apposition areas for typical acute Herbert and Fisher fractures for 10 dry bone specimens. Next, we modeled internal fixation for each of these fracture geometries with screws placed either along the central axis of the scaphoid or eccentrically, perpendicular to the fracture plane. We calculated the proportional areas occupied by the screw and remaining area available for fracture healing. The mean surface area of the simulated distal oblique, complete waist, and proximal pole fractures was 131, 86, and 58 mm(2), respectively. There was little difference in available area for complete waist and proximal pole fractures, but eccentric screw fixation perpendicular to the plane in distal oblique fractures consumed significantly less area than the centrally placed position. The area available for apposition is widely variable and depends on each bone's unique morphology, the orientation of the fracture plane, and the design of the screw. Of the 3 fracture patterns studied, the obliquity of the screw with respect to the long axis was greatest for distal oblique fractures where perpendicular (eccentric) placement is preferable to maximize surface area available for healing. Given the poor vascular supply of the scaphoid and morbidity associated with scaphoid fracture nonunions, this study examined a key determinant of bone healing by characterizing the area of these fractures and amount of bone apposition available for blood flow and healing when internally fixed with a compression screw.

Forming and fracture limits of aluminium alloy

Forming and fracture limits of an AA 3104-H19 aluminium alloy sheet were studied by hydraulic bulging and Marciniak type deep drawing and tensile tests. The alloy appeared to be highly anisotropic, exhibiting distinctly different fracture patterns in the rolling and transverse directions. The preferred fracture direction was transverse to the rolling direction. In the tensile test, samples loaded in the rolling direction failed transverse to the rolling direction, but in the transverse direction, the fracture was inclined at ∼55° to the tensile axis. In some cases, two such competing fractures in the characteristic directions could be observed. Scanning electron microscopy studies revealed a typical ductile fracture pattern. The fracture occurred by shearing in the through thickness direction, and typical alternating shear lips in a direction inclined at ∼45° to the through thickness direction could be observed. Forming limit diagrams for both rolling and transverse directions were determined from the experiments. The measured limit strains in uniaxial tension were predicted well by the modified Rice–Tracey theory, but in equibiaxial tension, the theory overestimated the fracture limit strains.

Fractal study for the fractured surface of Nd-Fe-B permanent magnets

Fractal study was used to the analysis of the fractured surface of commercial N50-type Nd-Fe-B sintered magnets. The strain-stress properties of the specimens indicate that the elastic and plastic deformations occur simultaneously during intergranual cracking. The microfractography of the specimens exhibits typical brittle fracture pattern with some toughness dimples, indicating that plastic deformation has happened in some local areas. A “line-measuring dimension” Dline was selected to discuss the fracture behavior. The calculated Dline is about 1.28 and 1.29 for the specimens with c-axis parallel and perpendicular to the applied force direction, respectively. The line-measuring dimension analysis indicates that the fracture feature may be isotropic for our studied specimens, which is a bit inconsistent with previous report on the fracture characterization of Nd-Fe-B sintered magnets. More comprehensive fractal study is further needed to confirm the fracture behavior in detail in the future.

Arthritis predicting factors in distal intraarticular radius fractures

Intra-articular malunion with step off and gap formation is claimed to be crucial for radiocarpal degeneration. In addition to well-defined intraarticular malunion, the shape of the distal radius is important for unaffected wrist function. In typical intra-articular fracture patterns with a dorsoulnar and palmar ulnar fragment, alterations of the shape of the articular surface, in a kind of a cavity, without obvious step off can be observed. The aim of the present study is to determine the residual articular deformity following intra-articular radius fractures and to analyze their impact on the final clinical and radiological outcome. Eighty one patients with dorsally displaced distal intraarticular radius fractures were followed up for a mean period of 9 years. Surgical treatment of all patients included open reduction, plate fixation and corticocancellous bone grafting. Radiological measurements included palmar tilt, radial inclination and radial shortening as defined by ulnar variance, intra-articular Stepps and the measurement of the anteroposterior distance of the radial joint surface. Clinical assessment included active range of motion (ARM) of the wrist, pain according to a visual analogue scale (VAS), grip power, working ability, Disability of Arm, Shoulder and Hand Score (DASH Score). Articular malunion in the form of a cavity in the sagittal plane measured 4.8mm, 1.3mm more than on the non-injured side. Anteroposterior distance measured 20.6mm, 2.1mm more than on the non-injured side. Articular step-off and gap was noticed in 11 patients. At the final follow-up examination, there was a significant difference in articular cavity depth and the anteroposterior distance between arthritis stage I and II. Arthritis stage was associated with the range of motion (ROM) in the sagittal plane, but had no significant influence on the DASH, pain level, grip strength and ROM in the frontal plane. ORIF leads to predictable results in the restoration of length and form of the distal radius. Increasing the articular cavity depth should be avoided to prevent degenerative arthritis at the radiocarpal joint at long-term follow-up visits.

Salter-Harris Type III Fractures of the Distal Femur

Salter-Harris (SH) III fractures of the distal femur, although rare, can have devastating effects. The purposes of this study were to: (1) compare the intra-articular fracture displacement measured on plain x-ray and magnetic resonance imaging (MRI) or computed tomography (CT) scan and (2) report the outcomes of patients with a SH III fracture of the distal femur. All SH III distal femur fractures treated at a large Children's Hospital with a Level I Pediatric Trauma Center between 1995 and 2006 were retrospectively reviewed. A total of 14 patients (average age: 13 y, 11 mo; range: 7 y, 8 mo to 17 y, 11 mo) with an average follow-up time of 21.50 months (range: 2 to 47 mo) were included in this study. Fracture displacement on plain x-ray was compared with the fracture displacement measured on MRI or CT scan. The average time between the initial plain x-ray and MRI or CT scan was 37.48 days (range: 3 h to 6 mo). Plain x-rays significantly underestimated the displacement of SH III fractures versus MRI or CT scan. Six patients who had both plain x-ray and MRI or CT scan had a measured displacement of 0.42 mm and 2.70 mm, respectively (paired Student t test, P=0.005). Ten of the 14 patients (71%) had no physical limitations and full knee motion at their most recent follow-up visit. The treatment of 4 patients (29%) was changed based on the findings of the additional MRI or CT scan. This study and earlier studies have shown a high rate of poor results with SH III fractures of the distal femur. This type of fracture pattern is extremely unstable and the true displacement is often underestimated by x-rays. Thus, it is strongly recommended that an MRI or CT scan be obtained on every SH III fracture of the distal femur. Moreover, any SH III fracture visible on plain radiographs should be treated with open reduction, internal fixation. Level IV.

Compressive fracture characteristics of Zr-based bulk metallic glass

The compressive fracture characteristics of Zr-based bulk metallic glass under uniaxial compression tests are studied. The zigzag rheological behavior is observed in the compression stress-strain curves of amorphous alloys. At room temperature the uniaxial compression fracture takes place along the plane which is at a 45-degree angle to the direction of the compressive stress. The microstructure of a typical fracture pattern is the vein network. A unique, finger-like vein pattern is found to exist at the fracture surface of Zr-based bulk metallic glass.

Nasoethmoid Orbital Fractures: Diagnosis and Treatment

Blunt trauma to the midface frequently results in fractures of the nasoethmoid orbital skeleton. These complex injuries are often misdiagnosed or inadequately treated and are perhaps the most difficult of all facial fractures to treat. The purpose of this article is to describe the author's technique for the diagnosis and treatment of these complex fractures. Presented is an organized approach to the diagnosis and surgical management of nasoethmoid orbital fractures that has evolved in the author's treatment of over 450 nasoethmoid fractures. Early diagnosis is confirmed by computed tomographic scan using the simple classification system described. Fractures that demonstrate displacement or movement on examination require open reduction and stabilization. Identifying the extent and type of fracture pattern and associated injuries determines the exposure and method of fixation needed. Wide exposure with meticulous reduction is necessary, with stabilization of the medial orbital rim fragment using a transnasal wire technique. Plate-and-screw fixation of the superior and inferior rim is performed with bone graft reconstruction of the nose as needed. Attention to redraping of soft tissue in the naso-orbital valley with the use of nasal compression bolsters is a crucial step in the repair. Multiple clinical cases are used to illustrate the different fracture patterns, soft-tissue injuries, and surgical technique recommended. This organized approach has proven effective in restoring preinjury appearance. Early diagnosis combined with the aggressive surgical techniques described will optimize results and minimize the late posttraumatic deformity.

Clinical Results of Surgical Treatment of Acetabular Fractures according to Quality of Reduction

Purpose: To analyze postoperative clinical and radiological results of displaced acetabular fractures and to determine the factors affecting the clinical results. Materials and Methods: Clinical analysis was performed on 51 patients with displaced acetabular fractures who had been operated on and followed up for a minimum of 1 year. The mean follow-up duration after surgery was 45 months (range, 12 to 67 months). The outcome was analyzed clinically using Postel's clinical grade criteria and radiologically using Mattas roentgenographic grading system. Results: There was a statistical relationship between the type of fracture patterns (Letournel classification) and the degree of immediate postoperative reduction (p＜0.05). A comparison of the radiological and clinical results at the last follow-up revealed a good correlation between good or excellent radiology results and good or excellent clinical results (p＜0.05). The factors affecting the clinical outcomes of the last follow-up were the type of fracture (Letournel classification), the presence or absence of a femoral head injury and the degree of immediate postoperative reduction. Conclusion: The results of this study suggest that the degree of reduction was closely related to the clinical result. Therefore, it is important in the surgical treatment of the acetabular fractures to classify the fractures accurately, reduce the fragments anatomically and minimize the complications.

Management of Acetabular Fractures in the Elderly Patient

Operative management of displaced acetabular fractures yields better results than nonoperative management. Over the past decade, surgical approaches to the acetabulum and the surgical tactic for repair of common fracture patterns have been advanced. Excellent outcomes after repair of these injuries can be achieved. In some cases, as in the elderly, or in those cases in which there is significant destruction of the articular cartilage, primary total hip arthroplasty may provide the best solution. Removal of the femoral head allows for excellent exposure of the acetabulum, making it possible to stabilize most fractures without the need for extensile or intrapelvic approaches. The surgical technique that has been successfully used calls for gaining primary stability of the acetabular columns by open reduction and internal fixation and then using the acetabular component to replace the articular surface. The columns need not be anatomically reduced. Multiholed acetabular shells can be used as internal fixation devices by placing screws into the columns enhancing the stability of the repair. In older individuals with severe osteoporosis, a typical fracture pattern results in intrapelvic dislocation of the femoral head with a blowout fracture of the anterior column and medial wall. Reinforcement rings with cemented acetabular fixation can be used in these cases. The femoral head can be used as bulk bone graft to replace and reinforce the reconstruction. Techniques common to revision of failed acetabular components are helpful in this setting. The results of reconstruction of severe acetabular fractures with total hip replacement have been reported to be similar to those achieved for reconstruction of osteoarthritis.

Neglected Femoral Diaphyseal Fracture

Femoral diaphyseal fractures usually result after trauma of high magnitude and because of this, can be life-threatening injuries or may result in considerable physical disability if not treated with care and caution. Nonoperative treatment of these fractures continues to be popular among the patient population in the Indian subcontinent, which in majority of cases, leads to healing in malalignment, shortening of the limb, chondromalacia patellae, and loss of knee motion. Although the majority of these fractures are being treated by operative methods today, success of the treatment depends largely on the surgeon's familiarity with the procedure or the type of fracture pattern (comminuted or segmental) particularly in a polytraumatized patient. Delayed union and nonunion of femoral-diaphyseal fractures and implant failures usually result after these procedures or the type of injury. The purpose of this study is to discuss various types of neglected femoral diaphyseal fractures and to review the literature on their treatment.

Micro-rotary fatigue of tooth–biomaterial interfaces

The bonding effectiveness of restorative materials to tooth tissue is typically measured statically. Clinically tooth/composite bonds are however subjected to cyclic sub-critical loads. Therefore, in vitro fatigue testing of dental adhesives should predict better the in vivo performance of adhesives. The objective of this study was to determine the fatigue resistance of two representative adhesives, a self-etch and an etch&rinse adhesive, bonded to enamel and dentin. Therefore, tooth/composite interfaces were cyclically loaded using a miniaturized version of a rotating beam fatigue testing device. Subsequently, the load at which 50% of the specimens fail after 105 cycles, was determined as the median micro-rotary fatigue resistance (μRFR). For both adhesives, the μRFR was about 30–40% lower than the corresponding micro-tensile bond strength (μTBS) to both enamel and dentin. Analysis of the fracture surfaces by Feg-SEM revealed typical fatigue fracture patterns. It is concluded that resin/tooth interfaces are vulnerable to progressive damage by sub-critical loads, with the 3-step etch&rinse adhesive being more resistant to fatigue than the 2-step self-etch adhesive.

Compressive fracture of Zr55Al10Ni5Cu30 bulk amorphous alloy at high temperatures

The fracture behavior of the Zr55Al10Ni5Cu30 bulk amorphous alloy under uniaxial compression at high temperatures has been investigated. At room temperature, the fracture occurred along the maximum shear plane which declined by 45° to the direction of the applied load, and a crack with serrated edge appeared on the ridge of the veins at the fracture surface for the Zr55Al10Ni5Cu30 bulk amorphous alloy. At high temperatures, the compressive fracture surface of the Zr55Al10Ni5Cu30 bulk amorphous alloy became much rougher than that at room temperature and steps appeared on the fracture surface. With increasing temperature, a different pattern from the vein-like morphology appeared on the fracture surface, which is very similar to the lava-flow. This type of fracture pattern is most likely due to the adiabatic heating created by plastic flow.

Quasistatic fractures in brittle media and iterated conformal maps.

We study the geometrical characteristic of quasistatic fractures in brittle media, using iterated conformal maps to determine the evolution of the fracture pattern. This method allows an efficient and accurate solution of the Lamé equations without resorting to lattice models. Typical fracture patterns exhibit increased ramification due to the increase of the stress at the tips. We find the roughness exponent of the experimentally relevant backbone of the fracture pattern, it crosses over from about 0.5 for small scales to about 0.75 for large scales. We propose that this crossover reflects the increased ramification of the fracture pattern.

The Problems of Locked Intramedullary Nailing in the Proximal Shaft Fractures of the Tibia

Proximal shaft fractures of the tibia have a high incidence of complication and often result in poor outcomes. Plate fixation and locked intramedullary nailing are the most common methods of treatment, but now the latter is more popular because of soft tissue problem, osteomyelitis etc.. The purpose of this study is to evaluate the results of locked intramedullary nailing in the treatment of proximal shaft fractures of the tibia and to draw a conclusion that what type of fracture patterns are the appropriate indication of nailing. We analyzed 18 proximal shaft fractures of the tibia which were treated by locked intramedullary nailing from October 1991 to March 1997 and followed more than 12 months. The results were as follows ; The complications were occurred in 12 cases(66.6%); 4 cases of delayed or non-union, 8 of angular deformity, 1 of leg length discrepancy. Delayed or non-unions were caused by fracture site comminution and bone defect. 5 anterior angular deformities were due to the pulling of the knee extensor mechanism and 3 valgus deformities were due to medially located entry portal.

Reflection of Nonlinear Waves in Crystal Lattices at Finite Temperatures, and Dynamic Fracture

Reflection of nonlinear waves, which are excited by impulsive forces, in one-dimensional crystal lattices at finite temperatures, and dynamic fracture of the lattice induced by the reflection are numerically analyzed using the basic statistical-mechanical equations proposed in the preceding paper. Enhancement of the strength of the reflected waves, and typical fracture patterns are found. Their physical implications are also briefly discussed. The equations are, therefore, confirmed to be valid for analyzing such nonequilibrium phenomena.

アルミニウム片埋込みエポキシ樹脂モデル試験片による冷熱サイクル試験の信頼性評価

Cyclic thermal stress tests were carried out by using aluminum chip embedded resin specimens as the model of an insulating epoxy material for semiconductor packaging or electrode molding in large scale apparatus, and the morphology of fracture pattern and the reliability were discussed.The tests showed four types of fracture patterns, and the life distribution of each fracture pattern obeyed Weibull distribution. Thus, in the case where the specimen fractured with several patterns, the statistical study has to be carried out for each pattern by determining the life distribution for each one in detail.The experiments made in different heating baths at various temperature conditions showed that the effects of these variables on lives depended on fracture patterns. The test results of the experiments with constant temperature difference showed that the mean life decreased with decreasing temperature range above the glass transition temperature (Tg). On the other hand, the test results with constant cooling temperature indicated that the temperature difference above Tg had an influence on the mean life, though the effect was less than that in the glassy state range.

En echelon crack-arrays in potash salt rock

There are two types of fracture patterns in the yield pillars of the potash mines of Saskatchewan. The individual members of both patterns are tensile (extension) fractures that propagate parallel with the maximum principal stress trajectory (perpendicular to the minimum principal stress). The difference between the two patterns lies in the arrangement of the member fractures. In theen echelon tensile crack-array, the macroscopic fracture consists of individual tensile cracks that are slightly offset from each other. They have only a small overlap and the child crack seems to form randomly on either side of its parent. Consequently, the en echelon tensile crack-array inherits the axial orientation of its members. In contrast, the tensile cracks of anen echelon shear crack-array, have a larger overlap and their lateral displacement from each other is biased in one direction. Therefore, the crack-array is no longer axial but inclined 20–25 degrees from the maximum principal stress direction. With increasing stress, the shear crack-array often collapses, forming theenvelope orhourglass structures of the potash mines.

Treatment of non-union after tibial shaft fracture with a full cortical thickness inlay bone graft.

Twenty-seven non-infected delayed union or non-union fractures of the shaft of the tibia in 26 patients were operated on with a full cortical thickness inlay graft taken from the injured leg. The initial trauma was moderate in 9 fractures and severe in 18. Fifteen fractures were closed injuries and 12 open. The fracture pattern was longitudinal in 5 cases, transverse in 11 and communited in 11. Surgery was performed 12 to 72 weeks (mean: 30 weeks) after the fractures had been sustained. All fractures healed after the bone grafting procedure. The time until union was established after surgery ranged from 6 to 37 weeks (mean: 17 weeks). The healing time was neither influenced by the initial type of fracture pattern (p > 0.05) nor by the fracture age at surgery (r = -0.21). Of 13 patients re-examined 8 to 16 years after surgery, the clinical results were classified as excellent in 8, as fair in 2, and as poor in 3 patients.