Transverse Fracture Line Research Articles

Iatrogenic Sciatic Nerve Injury in Posterior Acetabular Surgery: Surgeon More Predictive Than Position.

To identify factors that contribute to iatrogenic sciatic nerve palsy during acetabular surgery through a Kocher-Langenbeck approach and to evaluate if variation among individual surgeons exists. Retrospective cohort. Level I trauma center. Adults undergoing fixation of acetabular fractures (AO/OTA 62) through a posterior approach by 9 orthopaedic traumatologists between November 2010 and November 2022. The prevalence of iatrogenic sciatic nerve palsy and comparison of the prevalence and risk of palsy between prone and lateral positions before and after adjusting for individual surgeon and the presence of transverse fracture patterns in logistic regression. Comparison of the prevalence of palsy between high-volume (>1 patient/month) and low-volume surgeons. A total of 644 acetabular fractures repaired through a posterior approach were included (median age 39 years, 72% male). Twenty of 644 surgeries (3.1%) resulted in iatrogenic sciatic nerve palsy with no significant difference between the prone (3.1%, 95% confidence interval [CI], 1.9%-4.9%) and lateral (3.3%, 95% CI, 1.3%-8.1%) positions (P = 0.64). Logistic regression adjusting for surgeon and transverse fracture pattern demonstrated no significant effect for positions (odds ratio 1.0, 95% CI, 0.3-3.9). Transverse fracture pattern was associated with increased palsy risk (odds ratio 3.0, 95% CI, 1.1-7.9). Individual surgeon was significantly associated with iatrogenic palsy (P < 0.02). Surgeon and the presence of a transverse fracture line predicted iatrogenic nerve palsy after a posterior approach to the acetabulum in this single-center cohort. Surgeons should perform the Kocher-Langenbeck approach for acetabular fixation in the position they deem most appropriate, as the position was not associated with the rate of iatrogenic palsy in this series. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Distinct patterns of fracture propagation in distal radial fractures and the relationship to the ulnar head

BackgroundThe aim was to assess the direction of distal radius fractures and their relationship to the ulnar head. MethodsWe reviewed the 160 wrist radiographs. The fracture line was measured on the postero-anterior and lateral radiographs relative to the long axis of the forearm and the relationship to the ulnar head. FindingsPA radiographs: the fracture line ran distal ulnar to proximal radial (ulnar to radial) in 11%, transverse in 74% and distal radial to proximal ulnar (radial to ulnar) in 16%. Lateral radiographs: the fracture line ran distal volar to proximal dorsal in 88%, transverse in two 1% and dorsal to volar in 11%. Radial shift (7.5%) only occurred with ulnar to radial or transverse fractures.The ulnar to radial fracture line started at the proximal end of the ulnar head/distal radio-ulnar joint in 88%. The radial to ulnar fracture line started ended a mean of 2.5 mm proximal to the distal radio-ulnar joint (p < 0.01). The transverse fracture line started at the base of the distal radio-ulnar joint in 53% and proximally in 47%. InterpretationThere are two distinct coronal patterns: radial to ulnar ending c. 2 mm proximal to the distal radio-ulnar joint; ulnar to radial starting at the proximal distal radio-ulnar joint. There may be third pattern - transverse fractures; these may be variants of the above. Sagittally the main direction is volar to dorsal but 11% are obverse.This is the first description of distinct fracture patterns in extra-articular distal radius fractures. In addition the fracture patterns appear to correlate with different directions of force transmission which fit with our understanding of falling and the relatively uncontrolled impact of the wrist/hand with the ground.These patterns of fracture propagation help understand how the biomechanics of wrist fractures and may enable prediction of collapse.

Finite element analysis of the stability of retrograde intramedullary nail and plate-screw combinations for periprosthetic femoral fractures following total knee replacement.

Periprosthetic fractures following total knee replacement are rare but challenging. The goal of the treatment is to achieve the most stable fixation that allows early mobilization. Therefore, the aim of this study was to evaluate the biomechanical results of the use of different fixation systems in the treatment of distal femur periprosthetic fractures with finite element analysis. A total knee prosthesis was implanted in Sawbone femur models. A transverse fracture line was created in the supracondylar region and was fixed in four different groups. In group 1, fracture line fixation was fixed using retrograde intramedullary nailing. In group 2, fixation was applied using a lateral anatomic distal femoral. In group 3, in addition to the fixation made in group 1, a lateral anatomic distal femoral plate was used. In group 4, in addition to the fixation made in group 2, a 3.5 mm Limited Contact Dynamic Compression Plate (LC-DCP) was applied medially. Computed Tomography (CT) scans were taken of the created models and were converted to three-dimensional models. Axial and rotational loading forces were applied to all the created models. The least deformation with axial loading was observed in the double plate group. Group 3 was determined to be more advantageous against rotational forces. The greatest movement in the fracture line was found in group 2. The application of the medial plate was determined to reduce the tension on the lateral plate and increase stability in the fracture line. Combining a lateral anatomic plate with intramedullary nailing or a medial plate was seen to be biomechanically more advantageous than using a lateral plate or intramedullary nailing alone in the treatment of distal femoral periprosthetic fractures.

A novel patella fracture fixation technique: finite element analysis.

Patella fractures account for approximately 1% of all bone fractures. The tension band wiring technique has been used in surgical treatment. However, there is no clear information about the location of the K-wires in sagittal plane. Thus, a transverse fracture line was created in the patella finite element model and fixed with Kirchner (k) wires and cerclage at different angles and compared with two different standard tension band models. A total of 10 finite element models were created to study AO/OTA 34-C1 patella fractures. Two models used the classical tension band method with either circumferential or 8-shaped cerclage wire. The other 8 models used K-wires placed at 45° or 60°, either alone or combination with cerclage wire. A force of 200N, 400N, and 800N were applied at 45° knee angle and the resulting data fracture line opening, surface pressure and stress in the implants were analyzed through finite element analysis. When all the results are considered, it was determined that the K-wires 60° crossing at the fracture line and with cerclage modeling was superior to the other models. The diagonal placement of the K-wires with cerclage (could be 45° or 60° medium) was superior to the reference models. This study has shown that the new fixation method we propose could come to the fore as an alternative method to be used successfully in transverse patella fractures and lower complications. In transverse patellar fractures, the use of K-wires crossed at 60° may be a good alternative to the standard method.

Comparison of The Two Different Patella Fracture Fixation Technique: Finite Element Analysis

Introduction: Fractures of patella account for 1% of bone fractures and this type of injuries can lead to severe knee funciton restrictions due to its role in extansor mechanism. The most common type of fracture pattern is transverse or comminute. According to the guidelines, the most often used surgical techniques are modified tension band wiring and circumferential cercle wiring. However there is no clear information about the configuration of cerclage wiring in the tension band technique. For this purpose, a transverse fracture line was created in the patella finite element model and biomechanical comparison was made in both figure of eight and zero configurations&#x0D; Material and Method: A transverse fracture line was created in patella and the k-wires were directed proximally at 90 degrees in coronal plane, perpendicular to the fracture line. A cerclage wire was wound on each finite element model in figure of zero (reference 1 model) and figure of eight (reference 2 model) configurations. These models were compared with each other in finite element model, with the knee at a 45 degree flexion angle and applying 200 Nm, 400 Nm and 800 Nm of force.&#x0D; Results: When the opening amounts of reference 1 and 2 models were evaluated under 200 Nm, 400 Nm, and 800 Nm loads, it was found that there were 14%, 8%, 13% less openings in the reference 1 model, respectively. When the amount of pressure in the fracture line was evaluated under the same loads, the average pressure was 10%, 15% and 12% higher in the reference 1 model compared to the reference 2 model, respectively.&#x0D; Conclusion: When the determined parameters were evaluated, although the amount of opening at the fracture line was better in the reference 1 model, there was no significant difference between the parameters in both models. Both fixation types allow early motion in clinical applications and help the prevention of displacement of the fracture.

Is the T-shaped acetabular fracture really likes a "T"? A study based on three-dimensional fracture mapping

ObjectivesTo explore the morphological pattern of T-shaped acetabular fractures (T-SAFs) by mapping the fracture line using 3D software. Material and methodsWe retrospectively reviewed 1298 consecutive patients with acetabular fractures, and a total of 56 T-SAF patients were enrolled. After the simulated reduction of each fracture in the software, the fracture lines of all patients were overlaid and plotted on a template. A frequency heat map was generated according to the differences in fracture line density distribution. According to the location of fracture lines, all cases were divided into three groups: posterior group, anterior group, extra-posterior group. In surgically treated patients, the surgical approach, fixation methods, and reduction quality were recorded or evaluated. ResultsThe transverse fracture line was sinuous without involving the acetabular roof, and the longitudinal fracture line sloped forward or backward along the edge of the acetabular fossa to split the obturator foramen. The anterior and posterior edges of the acetabular fossa, the transition zone of the acetabular roof and anterior wall, the transition zone of the superior pubic ramus and anterior wall, and the posterior wall near the greater sciatic notch were areas with high rates of fracture incidence. The posterior group included 26 patients (46.4%) and the distribution of fracture lines resembled a “T” or “Y”. The anterior group included 25 patients (44.6%) and the distribution of fracture lines resembled a “7″. The extra-posterior group included 5 patients (8.9%) and the fracture lines run through the ischial body. The surgical strategies vary among different groups of T-SAF patients. ConclusionOur findings shed light on the characteristics of fracture lines for T-SAFs and provide a reference for surgical treatment strategies.

Ferreira-Ishida Technique: Spare Roof Technique B. Step-by-Step Guide to Preserving the Bony Cap While Dehumping.

For V-shaped nasal bones, the authors consider that ostectomy of the dorsal keystone area can be avoided, and this has led to the development of a new preservation technique: the spare roof technique B (or Ferreira-Ishida technique), where the bony cap is preserved. It includes six main steps, as follows. Step 1, draw on the surface of the skin the desired dorsal brow-tip aesthetic lines, the pyriform aperture, the rhinion, and the amount of triangular bone that has to be taken out to allow pushing-down the bony cap, and the transversal line in the beginning of the nasal hump. Step 2, release the upper lateral cartilages from the dorsal septum ("high septal strip"). Step 3, take out the amount of dorsal septum necessary to dehump. Step 4, perform the paramedian high parallel osteotomies exactly below the marked brow-tip dorsal aesthetic lines. Then, perform the second group of lower osteotomies, until the E-point, to achieve a triangular shape of bone in each side of the bony cap. Perform the ostectomy of the mentioned triangular areas. Release the lateral keystone area. Perform partial ultrasonic ostectomy endonasally, below the nasal bones, to promote the weakening of the transverse fracture line, in the sagittal plane just above the E-point. Push-down gently the rectangular bony cap with a Luc nasal forceps (19 cm) in a greenstick fashion. Perform lateral traditional osteotomies from high to low to high to narrow the bony bridge as much as is needed. Step 5, perform a regular L-shape Cottle septoplasty (if necessary). Step 6, suture the cartilaginous middle vault (upper lateral cartilages) to the dorsal aspect of the remaining septum.

Fracture patterns in midshaft clavicle fractures

Current classifications of midshaft clavicle fractures are based on radiography. The aim of the study was to evaluate the fracture pattern of clavicle fractures using 3-dimensional computed tomography (3D CT). A retrospective analysis was performed on CT scans of 65 acute clavicle fractures. Using quantitative 3D CT reconstruction techniques, the fracture of the clavicle was virtually reduced. Based on these reconstructions, a group-based fracture heat map and small fragment heat map, and the location of the most common fracture line were determined. Also, the direction and amount of displacement were evaluated. Three fracture patterns could be distinguished. The primary fracture line in type 1 is going from posteromedial to anterolateral and located between 50% and 68% of the clavicle's length. In type 2, a transverse fracture line is located around 55%, and in type 3, a superolateral to inferomedial line is located between 47% and 56%. Wedged fracture fragments can be seen in types 1 and 2 and are mainly situated inferiorly. The displacement is similar in all types, but the main direction of displacement is specific for the different types (posterior, anterior, inferior). We can conclude that several fracture patterns can be seen in clavicle fractures. Most fractures are located laterally at the midshaft of the clavicle. Wedged segments are mainly located inferiorly, and at the posterior part of the clavicle, no comminution is ever seen. The direction of displacement depends on the fracture pattern.

Biomechanical approach to the choice of the type of intramedullary fixator in a simulated femoral fracture

Intramedullary osteosynthesis is currently one of the main methods of treating fractures of long tubular bones. There is a large selection of both the fixators themselves and the manufacturers of these implants. The aim of this study was to conduct biomechanical testing of three types of intramedular rods – ChM, BNB (three-bladed), SarNIITO rod and Fixion (Israel) in femoral fractures of types A1, A2, A3 and B1. According to the results of the study of the displacement of fragments in different types of fractures, affecting the “bone– fixator” system with three types of loads (axial, transverse and rotational) – the stability is not the same. The most commonly used cross-blocking rod (or perhaps the entire type of such rods) showed fairly good indicators of the stability of fragments that can lead to the desired result – bone fusion. The use of different types of intramedullary fixators based on a different method of locking in the bone (transversely inserted screws, by expanding in the bone marrow canal, embedding the blades into the bone from the inside and with a spoke) allows a more rational approach to increasing the stability of a fixed fracture by using their positive sides. So, for a fracture of type A1 and A2, it is better to use Fixion rod. With a transverse bone fracture line (type A3), it is better to give preference to the three-bladed BNB rod, since it holds the transverse and rotational load better, and when exposed to the axial one, the fracture is autodynamized (compression), stimulating regeneration. Fractures of type B2 (comminuted, with a small contact line between the fragments) require the maximum possible stability. For this purpose, Fixion rod is better suited, which is blocked throughout the entire bone marrow canal. But when it is used, it is possible for the fragment to move away from the mother bed when the rod is stabilized by its expansion.

Differential diagnosis of benign and malignant vertebral fracture on CT using deep learning

To evaluate the performance of deep learning using ResNet50 in differentiation of benign and malignant vertebral fracture on CT. A dataset of 433 patients confirmed with 296 malignant and 137 benign fractures was retrospectively selected from our spinal CT image database. A senior radiologist performed visual reading to evaluate six imaging features, and three junior radiologists gave diagnostic prediction. A ROI was placed on the most abnormal vertebrae, and the smallest square bounding box was generated. The input channel into ResNet50 network was 3, including the slice with its two neighboring slices. The diagnostic performance was evaluated using 10-fold cross-validation. After obtaining the malignancy probability from all slices in a patient, the highest probability was assigned to that patient to give the final diagnosis, using the threshold of 0.5. Visual features such as soft tissue mass and bone destruction were highly suggestive of malignancy; the presence of a transverse fracture line was highly suggestive of a benign fracture. The reading by three radiologists with 5, 3, and 1 year of experience achieved an accuracy of 99%, 95.2%, and 92.8%, respectively. In ResNet50 analysis, the per-slice diagnostic sensitivity, specificity, and accuracy were 0.90, 0.79, and 85%. When the slices were combined to ve per-patient diagnosis, the sensitivity, specificity, and accuracy were 0.95, 0.80, and 88%. Deep learning has become an important tool for the detection of fractures on CT. In this study, ResNet50 achieved good accuracy, which can be further improved with more cases and optimized methods for future clinical implementation. • Deep learning using ResNet50 can yield a high accuracy for differential diagnosis of benign and malignant vertebral fracture on CT. • The per-slice diagnostic sensitivity, specificity, and accuracy were 0.90, 0.79, and 85% in deep learning using ResNet50 analysis. • The slices combined with per-patient diagnostic sensitivity, specificity, and accuracy were 0.95, 0.80, and 88% in deep learning using ResNet50 analysis.

Disturbance of osteonal bone remodeling and high tensile stresses on the lateral cortex in atypical femoral fracture after long-term treatment with Risedronate and Alfacalcidol for osteoporosis

An 83 year-old Japanese woman complained of left lateral thigh pain following a low-energy fall 4 months prior to admission. She had been treated for osteoporosis with Risedronate and Alfacalcidol for the previous five years. She was diagnosed with an atypical femoral fracture (AFF) according to the American Society for Bone and Mineral Research (ASBMR) Task Force revised criteria. Radiographs revealed cortical thickening and a transverse radiolucent fracture line in the lateral cortex of the shaft. MRI showed a high intensity signal on the T2WI image 1 cm long in the lateral cortex. The patient had normal levels of bone resorption and formation biomarkers except for low 25(OH) Vitamin D. Double fluorescent labeling was done preoperatively.Due to significant bowing, a corrective osteotomy and intramedullary nailing were performed, and the resected bone wedge was analyzed by bone histomorphometry. Three ground sections of the lateral cortex at the fracture site showed many and large pores, with or without tetracycline labeling. Histomorphometric assessment was done on intracortical pores, classified by a novel criteria, only to assess size of the pores to know prolonged osteoclastic activity and its characteristics of inner surfaces to assess whether bone formation has been occurring or not in labeling period in remodeling cycle, and coalition of multi-pores. Increased size with widespread variation of pores suggested prolonged osteoclastic activity in the reversal/resorptive phase. Bone labeling showed lamellar bone on the endocortical surface.We hypothesize that the case had developed from a regional disturbance of osteonal remodeling in the lateral cortex, in which accumulated microcracks might have initiated a resorption process resulting in resorption cavities, i.e., pores, which became larger due to prolonged activity of secondary osteoclasts. Various sized pores could form lamellar bone, still forming at the time of biopsy, some had formed lamellar bone, but stopped to form before labeling and not to start to form at all, probably due to incomplete coupling. Endocortical lamellar bone might had started to resorbed to smooth off endocortical surface, followed by formation of lamellar bone. The endocortical bone formation was assessed and its formation period is about 2.7 years.A finite element analysis using preoperative CT data revealed high tensile stresses on the lateral aspect of the femur. Histomorphometric results suggest that there might be more pores in the tensile area than the compressive area. These findings may subsequently connect accumulation of microcracks, an increase of size and number of pores and coalition and subsequent fracture in the lateral cortex.

Biomechanical Analysis of the Kirschner-Wire Depth of the Modified Tension Band Wiring Technique in Transverse Patellar Fractures: An Experimental Study Using the Finite-Element Method.

BackgroudModified tension band wiring is one of the most preferred surgical methods for transverse patellar fractures. However, the optimal depth or sagittal position of a Kirschner wire (K-wire) in modified tension band wiring has yet to be determined. The purpose of this study was to evaluate whether the depth of a K-wire affects the biomechanical characteristics of modified tension band wiring using the finite-element method.MethodsA patella model was designed with a cuboid shape (length, 34.3 mm; width, 44.8 mm; and thickness, 22.4 mm) and divided into the cortical and cancellous bone parts. A transverse fracture line was formed on the midline of the cuboid shape model. The cuboidal model was applied to modified tension band wiring. The depth or sagittal position of the K-wire was divided into superficial, center, and deep. With the Abaqus v2017 program (Dassault System Inc.), the distal part of the model was fixed, and a tensile load of 850 N was applied to the proximal part of the model at an angle of 45°. The maximum pressures of the cortical and cancellous bones at the fracture plane were measured. The largest von Mises values of the K-wire and stainless steel wire were also measured. The fracture gap on the distracted or anterior side was measured.ResultsIn deep K-wire placement, the highest peak von Mises values of the cortical and cancellous bones were observed. The K-wire and stainless steel wire showed the highest von Mises values in deep K-wire placement. The fracture gap was also largest in deep K-wire placement.ConclusionsThe depth of the K-wire affects the biomechanical characteristics of modified tension band wiring. Deep placement of the K-wire will be more favorable for bone union than the empirically known 5-mm anterior or center placement of the K-wire.

Is initial interfragmentary compression made to last? An ovine bone in vitro study.

Interfragmentary compression, a major principle of fracture treatment, is clinically not quantified and might be lost quickly even without functional loads. We designed an experimental study hypothesizing that (1) compression can be controlled using either lag screw or compression plate, and expecting similar initial compression, (2) loss of interfragmentary compression through relaxation within one hour is reduced with neutralization locking plate next to lag screw compared to compression plate. Twelve ovine femora (N=6) and humeri (N=6) were assigned into groups: Group 1 received a 45° oblique osteotomy at mid-diaphysis and was fixated using a 3.5mm interfragmentary lag screw and locking compression plate (3.5mm LCP, DePuy Synthes) as neutralization plate. Group 2 received a transverse osteotomy and was fixated with dynamic compression using compression plate (LCP). Interfragmentary pressure and relative bone fragment displacements were recorded over one hour. Median loss of compression over one hour time (relaxation) were 0.52% in Group 1, and 0.17% in Group 2 (p>0.05). Median rotational displacements amounted to 0.46° for Group 1, and 0.31° for Group 2, and axial displacement to a median of -20μm in Group 1 and 25μm in Group 2. Ovine bone interfragmentary stress relaxation maintains compression over the first hour for lag screw with neutralization plate for an oblique fracture line or compression plate for a transverse fracture line. Measured compression forces around 100N could be overcome by physiological tension loading in bending or torsion, necessitating for instance tension band plating, additional lag screws or absolutive stability.

Morphologic Characteristics of the Medial Malleolar Fragment based on CT Scan in Ankle Fractures

Category:Ankle; TraumaIntroduction/Purpose:The aim of this study was to describe and evaluate the morphologic characteristics of the medial malleolar fragment in ankle fractures and suggest the guideline for proper fixation of the fragmentMethods:From August 2011 to June 2018, 172 cases were enrolled. There were performed the operation in ankle fractures with a medial malleolar fragment. All cases were divided into three types, based on the transverse fracture line of the medial malleolar by the CT (computed tomography) scan; type 1 was involved in the anterior colliculus, type 2 was the intercollicular groove and type 3 was the posterior colliculus. All cases were classified by Lauge-Hansen classification and compared with the groups statistically. The fixation methods by the groups were reviewed and compared. All cases were analyzed by SPSS 19.0, the p-value was less than 0.05.Results:According to the CT scan, type 1 was 14 cases (8.1%), type 2 was 48 cases (27.9%) and type 3 was 110 cases (63.9%). Based on the Lauge-Hansen classification, SER (supination-external rotation) type was 136 cases(76.4%), PER (pronation-external rotation) was 30 cases(17.4%) and PA(pronation abduction) was 8 cases(4.7%).In SER type, type 1 was 6 cases(4.4%), 2 was 42 cases(30.9%) and 3 was 86 cases(63.2%). In PER type, 1 was 6 cases (20%), 2 was 4 cases (13.3%) and 3 was 20 cases (18.9%). In PA type, 1 was 2 cases (25%), 2 was2 cases (25%) and 3 was 4 cases (50%). The fixation methods were various, such as a tension band wiring, 4.0 cannulated screw, hook plate.Conclusion:The morphology of a medial malleolar fragment based on CT scan in ankle fractures were 3 types. There was common a morphology involved the posterior colliculus, Type 3. We suggest that the operators should choose the proper fixation method by the morphology of the fragment and should be careful to avoid the injury of the posterior tibialis tendon.

MON-356 Atypical Femur Fracture with Denosumab

Background: Osteoporosis (OP) is a systemic disease that is associated with increased risk for fractures. Anti-resorptive medications (ARM) are an effective modality for treatment and prevention of fractures in OP. Long-term use of ARM like bisphosphonates (BP) is associated with increased risk of atypical femoral fractures (AFF). Denosumab (DM) is monoclonal antibody that targets receptor activator of nuclear factor KB ligand (RANKL). A few cases of AFF with DM have been reported in patients who have previously been on long term BP therapy. We present a case where the patient had only received two zoledronic acid (ZA) infusions, last one three years prior to being initiated on DM and experienced AFF. Case: 73-year-old postmenopausal woman presented to the emergency room with sudden onset pain in the right thigh. Patient was standing and reaching into her closet when she felt a snap in right thigh followed by inability to move the right leg or bear weight on it. X-ray of the right femur showed a displaced femoral shaft fracture with a short transverse fracture line and a spike, without comminution.History was significant for OP for which she received raloxifene for a couple of years followed by ZA in 2013 and 2015 by her primary care. Fracture history was significant for a wrist fracture in 2015, and T12 and L1 fractures in 2017 from coughing while on Medrol dospak for an acute episode of bronchitis. In 2017, bone density showed L1-L4 T score of -2.0, the left total hip T score was -1.8 and left femoral neck T score was -2.5 consistent with OP. Work up for secondary causes of OP was unremarkable. Due to recent T12 and L1 compression fractures, she was recommended DM. She received DM in June 2018 as she was undergoing a dental implant followed by December 2018 and June 2019 and presented with the right femoral fracture in November 2019.Past history was significant for idiopathic pulmonary fibrosis which had been relatively stable without need for long-term steroid therapy. History was negative for diabetes or kidney disease. Menarche was at age 14, menopause at 52 and she did not take any hormone replacement therapy.She underwent surgical fixation with intramedullary rod. Due to concern about ARM associated sub-trochanteric fracture in the right femur, left femur was imaged. She had cortical beaking in the distal third of the left femur, and underwent prophylactic medullary nailing of the left femur as well. Conclusion: AFF are an uncommon complication of ARM used for OP. Not many cases of AFF have been reported with the use of DM and most of the reported cases are associated with prolonged BP therapy. Our case is unusual in that AFF occurred in the absence of prolonged BP therapy and raises concern that a couple of ZA infusions in the past can also increase the risk of AFF. Clinicians need to have a high index of suspicion and may consider doing femur x-rays in patients who have previously been on BP prior to starting DM.

Fracture Patterns and Comminution Zones in OTA/AO 34C Type Patellar Fractures.

To characterize the fracture patterns and comminution zones for complete articular (OTA/AO 34C type) patellar fractures, using a computed tomography mapping technique. Eighty-three OTA/AO 34C type patellar fractures were included. Images of patellar fractures were superimposed on a coronal template of the patella, created from a healthy right knee, to identify fracture patterns and comminution zones. Our analysis was based on 83 computed tomography images of patellar fractures, contributed by 69 male and 14 female patients (mean age, 52 years; range, 18-79 years), and included 13 type C1, 26 type C2 and 44 type C3 fractures. A transverse fracture, including both the medial and lateral facets, was the most common fracture pattern, identified in 92.8% of cases. In the C1 and C2 types, the fracture line affecting the medial and lateral joint surface was either transverse or oblique. In the C3 type, the transverse and vertical fracture line of the medial articular surface extended to the inferior pole of the patella, with transverse and oblique fractures lines on the lateral joint surface. In addition, a concentration of the fracture lines around the vertical ridge was observed. The patterns of fracture lines and comminution zones OTA/AO 34C type fractures were repeatable on the constructed maps. A transverse fracture line on the inferior pole which was observed in the C2 and C3 type fractures may be used for the modification of current classification systems to direct treatment.

Classifications in Brief: The Denis Classification of Sacral Fractures.

Classifications in Brief: The Denis Classification of Sacral Fractures.

Spinopelvic dissociation in patients suffering injuries from airborne sports.

Spinopelvic dissociation which is also called U-type or referred to H-type sacral fractures with a transverse fracture line is an infrequent injury that results mainly from high-energy accidents. This results in an osseous dissociation of the upper central segment of the sacrum and the entire spine from the lower sacral segments. The purpose was to investigate the incidence of spinopelvic fracture in general among airborne injuries. Using our electronic patient records, we retrospectively investigated all sacral fractures related to airborne sports between 2010 and 2017. All injuries were classified according to the Roy-Camille, Denis, AOSpine and the Tile classification system. During the period of interest, 44 patients (18.7%) were admitted with sacral fractures after accidents obtained from airborne sports, including 16 spinopelvic dissociations (36.4%). The majority of these injuries were obtained from paragliding (75.0%), followed by BASE jumping (21.4%) and parachuting (4%). The mean injury severity score(ISS) in the spinopelvic dissociation group was significantly higher compared with other sacral fracture group (38.1 vs. 20.0; p < 0.001). Six lambda-type, four T-type, four H-type and two U-type injuries were identified. In total, four patients (25%) were found to have neurological impairment. For treatment, 87.5% of patients underwent subsequent surgical stabilization. Airborne sports have high potential for serious, life-threatening injuries with a high incidence of spinopelvic dissociation. In the literature, the prevalence of spinopelvic dissociation in sacral fractures is described to be between 3 and 5%. In our series, the prevalence is 36.4%. It is important to identify the potential injuries promptly for the further treatment. These slides can be retrieved under Electronic Supplementary Material.

Radiological criteria for atypical features of femur fractures: what we can learn when applied in a clinical study setting.

Assess American Society of Bone and Mineral Research (ASBMR) criteria for identifying atypical femoral fractures (AFFs). Two orthopedic surgeons independently evaluated radiographs of 372 fractures, applying ASBMR criteria. We assessed ease of applying ASBMR criteria and whether criteria-based assessment matched qualitative expert assessment. There was up to 27% uncertainty about how to classify specific features. 84% of films were classified similarly for the presence of AFF according to ASBMR criteria; agreement increased to 94% after consensus meeting. Of 37 fractures categorized as AFFs based on ASBMR criteria, 23 (62.2%) were considered AFFs according to expert assessment (not relying on criteria). Only one (0.5%) femoral shaft fracture that did not meet ASBMR criteria was considered an AFF per expert assessment. The number of major ASBMR features present (four vs five) and whether there was periosteal or endosteal thickening ("beaking" or "flaring") played major roles in the discrepancies between ASBMR criteria-based and expert-based determinations. ASBMR AFF criteria were useful for reviewers but several features were difficult to interpret. Expert assessments did not agree with the ASBMR classification in almost one-third of cases, but rarely identified an AFF when a femoral shaft fracture did not meet ASBMR AFF criteria. Experts identified lateral cortical transverse fracture line and associated new-bone formation along with no or minimal comminution as crucial features necessary for the definition of atypical femoral fractures.

Mind the gap between the fracture line and the length of the working area: a 2-D finite element analysis using an extramedullary fixation model

ObjectiveTo determine the ideal working area for a simple transverse fracture line treated with a bridge plate. MethodsA 2-D finite element analysis of a hypothetical femur was performed for the quantitative evaluation of a large-fragment titanium alloy locking plate based on the precept of relative stability in a case of a simple transverse diaphyseal fracture. Two simulations (one case of strain and another case of stress distribution) were analyzed in three unique situations according to the von Mises stress theory. Load distributions were observed when the bone was subjected to a single vertical load of 1000N. ResultsThe longer the length of the implant flexion, which coincided with the working area of the plate, the greater the flexion of the implant. The highest concentrations of stress on the plate occurred in the region around the screws closest to the bone gap. The closer the screws to the fracture site, the greater the demands on the plate. ConclusionWhen using a large-fragment titanium alloy locking plate to stabilize a simple transverse fracture based on the precept of relative stability (bridge plate), there must be considerable distance between the proximal and distal screws closest to the fracture line. The farther away this fixation is, the lower the stress on the plate and the greater the dissipation of force in the form of deflection.