Delta Frame Research Articles

Delta Frame Versus Blocking Wire in Management of Mallet Finger. Which has Better Surgical Outcome? A Systematic Review and Meta-Analysis

Delta Frame Versus Blocking Wire in Management of Mallet Finger. Which has Better Surgical Outcome? A Systematic Review and Meta-Analysis

The Effects of Percutaneous Coronary Intervention on the Flow in Acute Coronary Syndrome Patients-Geometry in Focus.

Evaluation of the effect of three dimensional (3D) coronary plaque characteristics derived from two dimensional (2D) invasive angiography images (ICA) on coronary flow determined by TIMI frame count (TFC) in acute coronary syndrome (ACS) has not been thoroughly investigated. A total of 71 patients with STEMI, and 73 with NSTEMI were enrolled after primary angioplasty. Pre- and post-PCI TFCs were obtained. From 2D images, 3D reconstruction was performed of the culprit vessel, and multiple plaque parameters were measured. In STEMI, the average post-PCI frame count decreased significantly, resulting in better flow. With regards to 2/3D parameters, no differences were found between the STEMI and NSTEMI groups. The 3D parameters in the subgroup with an increase with at least three frames resulting in worsening post-PCI flow were compared to parameters of the patients with improved or significantly not change flow (delta frame count < 3), and greater minimal luminal diameter and area was found in the worsening (increased) frame group. In STEMI 2/3D, parameters showed no correlation with worsening flow, whereas in NSTEMI, greater minimal luminal diameter and area correlated with decreased flow. We can conclude that certain 2/3D parameters can predict slower flow in ACS, resulting in the use of GP IIb/IIIa receptor blocker.

Fracture union in extra articular distal tibia fracture after definitive delta frame external fixation in COVID 19 pandemic: a case report

&lt;p class="abstract"&gt;Distal tibia fractures account for 10% of lower limb fractures. Mode of trauma also determines the fate of soft tissue recovery. In low energy fractures soft tissue show better healing whereas fractures due to high energy trauma show high chances of soft tissue complications like poor soft tissue coverage, wound infection and necrosis. We presented a 50 years old male case of extra articular left distal tibia fibula open fracture managed by delta frame external fixator with fibular K wiring used as a definitive management with good fracture healing and range of motion 5 months postoperative. Ankle spanning external fixation is a good modality of surgical management of extra articular compound distal tibia fractures as both temporary and definitive surgical fixation.&lt;/p&gt;

Adding a First Metatarsal Pin to An Ankle Tubular External Fixator Does Not Reduce the Incidence of Early Reduction Loss

External fixation with a bilateral frame configuration (delta frame, DF) is a routine approach for treating ankle fractures and dislocations with severe soft tissue damage. The purpose of this study was to evaluate to what extent adding a first metatarsal fixation contributes to the stability of the fixation as evidenced by reduced frequency of early loss of reduction. A retrospective study was performed to compare the rate of early reduction loss in patients treated with a bilateral frame external fixation as part of a 2-stage treatment protocol for periarticular ankle fractures, in a level one trauma center between 2006 and 2016. The cohort was divided into 2 groups according to the frame configuration that had been used: DF only and DF with first metatarsal fixation (DF+1MT). A multivariate analysis assessing risk factors for postoperative loss of reduction was conducted. A total of 67 patients were included in the study, of which 30 underwent fixation by DF and 37 by DF+1MT. Early loss of reduction was recorded in 13 (19.4%) patients, 6 (20%) in the DF group and 7 (18.9%) in the DF+1MT group (p = .576). None of the assessed risk factors reached statistical significance. To conclude, the addition of a first metatarsal pin as an enhancement of external fixation with a delta frame configuration did not reduce the incidence of early loss of reduction. There is no evidence to support the claim that adding this pin contributes to the stability of the fixation in a clinically relevant manner.

A prospective interventional study of external fixator and delta frame as primary and definitive mode of treatment for open tibial fractures

A prospective interventional study of external fixator and delta frame as primary and definitive mode of treatment for open tibial fractures

Two-Stage Surgical Procedure in Intra-articular Distal Tibiofibular Fractures with Soft Tissue Injury: in Which Stage Should the Fibular Plate be Applied at Initial Surgery?

Introduction:The selection of the stage where fibular plate was performed in two-stage surgery of the intra-articular distal tibiofibular fractures with soft tissue injury is still controversial. The aim of the study was to compare the complications, radiological and functional outcomes between the patients who had fibular plate at initial or second phase during surgical management of such fractures.Materials and Methods:In this study, medical records of 47 patients who underwent a two-stage surgical procedure for intra-articular distal tibia fractures accompanying soft tissue injury were retrospectively examined. Delta frame was applied in all cases within 24 hours following admission to the emergency department in accordance with AO principles. Those cases where fibular plate was applied during the initial stage and the second stage were classified as Group 1 and Group 2 in order to compare recorded data between the two groups.Results:According to the results of the study, there were 25 cases in Group 1 and 22 cases in Group 2 in which fibular plate was applied at the first stage and the second stage, respectively. The mean follow-up was found as 27.7±7.0 months in Group 1 and 28.2±6.2 months in Group 2 (p=0.778). No difference was found between the two groups in terms of the age, sex, hospital stay, the time between two surgical procedures, tibiofibular angle and AOFAS scoring (p>0.05).These two groups were also similar in mechanism of injury, Denise-Weber or AO classification, rates of tibiofibular malalignment on post-operative CT, fibular rotation, intra-articular tibial step-off, tibial varus-valgus duration of union, rate of infection, fibular angulation and the presence of the flap/graft/debridement (p>0.05).Conclusion:In conclusion, two-stage surgical procedure in intra-articular distal tibiofibular fractures may be an effective method decreasing soft tissue complications. The timing of the open reduction and internal fixation of the fibula at different stages may not necessarily have an impact on the success of the post-operative tibial reduction, the total duration of surgery, syndesmosis malalignment or soft tissue complications.

Three-Dimensional Modeling and Finite Element Analysis of an Ankle External Fixator

External fixator has played an important role in repairing fractured ankle bone. This surgery is done due to the several factors which are the bone is not normal position or has broken into several pieces. The external fixator will help the broken bone to grow and remodel back to the original appearance. However, there are some issues regarding to the stability of this fixation. Improper design and material are the major factor that decreased the stability since it is related to the deformation of the external fixator to hold the bone fracture area. This study aims to design a stable structure for constructing delta frame ankle external fixator to increase the stability of the fixation. There are two designs of external fixator with two types of material used in this present study. Both external fixators with different materials are analyzed in terms of von Mises stress and deformation by using a conventional Finite Element Analysis software; ANSYS Workbench V15. The result obtained shows the Model 1 with stainless steel has less stress and deformation distributions compared to the Model 2. Hence, by using Model 1 as the external fixator, the stability of the fixation can be increased.

Spanning External Fixation for Pilon Fractures: Steering Wheel and Kickstands.

High-energy pilon fractures are challenging for patients and surgeons. Joint-spanning external fixation can be used successfully as temporary stabilization in a staged fashion. Despite this common strategy, there are varying types of external fixator applications. The authors present an efficient and easily reproducible modification to the classic delta frame configuration, which may afford improved fracture reduction and prevent decubitus lesions. [Orthopedics. 2020;43(3):e187-e190.].

Biomechanical features of six design of the delta external fixator for treating Pilon fracture: a finite element study.

Pilon fractures can be caused by high-energy vertical forces which may result in long-term patient immobilization. Many experts in orthopedic surgery recommend the use of a Delta external fixator for type III Pilon fracture treatment. This device can promote immediate healing of fractured bone, minimizing the rate of complications as well as allowing early mobilization. The characteristics of different types of the Delta frame have not been demonstrated yet. By using the finite element method, this study was conducted to determine the biomechanical characteristics of six different configurations (Model 1 until Model 6). CT images from the lower limb of a healthy human were used to reconstruct three-dimensional models of foot and ankle bones. All bones were assigned with isotropic material properties and the cartilages were assigned to exhibit hyperelasticity. A linear link was used to simulate 37 ligaments at the ankle joint. Axial loads of 70 and 350N were applied at the proximal tibia to simulate the stance and swing phase. The metatarsals and calcaneus were fixed distally in order to prevent rigid body motion. A synthetic ankle bone was used to validate the finite element model. The simulated results showed that Delta3 produced the highest relative micromovement (0.09mm, 7μm) during the stance and swing phase, respectively. The highest equivalent von Mises stress was found at the calcaneus pin of the Delta4 (423.2MPa) as compared to others. In conclusion, Delta1 external fixator was the most favorable option for type III Pilon fracture treatment. Graphical abstract ᅟ.

A prospective study of delta frame as external fixator for open-distal tibial fractures

Distal tibial fractures pose a serious challenge to the orthopaedician because muscular coverage is very less and poorly vascularized [1]. It is further complicated by comminution, joint involvement, open fractures and high energy trauma [1]. The goals of management are proper care of the injured soft tissues, restoration of joint congruity, stable fixation [2]. Ankle spanning external fixation ie Delta frame has become the initial treatment of choice for complex tibial pilon fractures [3]. The ‘tripolar configuration’ allows facilitation of wound care, plastic procedures and good xray or CT images [4]. The Delta external fixator was found to be the most stable external fixator for treating not stable as type III according AO/OTA’s classification [5]. The IM nails often do not provide enough stability in distal tibial fractures and plating requires extensive soft tissue dissection [6]. External fixators can also be used in osteoporotic and unreconstructable comminuted metaphyseal fractures with poor bone stock [6]. However literature support is scanty, hence we decided to do the above study with an aim to analyze its results using the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle Hindfoot score.

Use of optokinetics based OKCSIB protocol in restoring mobility in primary progressive MS

The case is of a mid-40s patient who developed progressive muscle weakness and loss of mobility over 6 weeks due to primary progressive multiple sclerosis. 2.5 days before admission, she...

Treatment of humerus supracondylar nonunion with pin and plate fixation as a simple device

Introduction Pin and plate fixation as an effective internal fixation for humerus supracondylar fracture has been introduced. It is especially useful in difficult cases with comminuted fractures or very low fracture line. We used this technique for treatment of difficult cases of humerus supracondylar nonunions and reviewed its results. Material and methods From October 2008 to September 2014, 27 patients with humerus supracondylar nonunion underwent open reduction and internal fixation with pin and plate in one or both column with or without bone grafting. Results and complications were evaluated. Surgical technique of pin and plate After preliminary reduction two or more 1.2 mm pin inserted cross nonunion site like a preliminary fixation. Pins were bent to be placed on the humeral posterior cortex, a 3.5 mm three or four holes reconstruction plate put on the pins and was fixed to humerus with two screws. In the cases with very small distal segment as an alternative, the pins inserted parallel to articular surface and were bent at both side and be placed on humerus as a delta frame and were fixed with a plate on them. Results In 6 years we had 27 patients with supracondylar humerus nonunion that pin and plate fixation was used as fixation device for one column in 12 of them and for both column in 15 of them. Age of the patients was 19 to 68 (mean 51) years. Union has been achieved in all of the cases but nonunion of olecranon osteotomy occurred in three patient till last follow-up and we had to remove the implants in 11 patients. Conclusion Pin and plate fixation is a simple and effective technique for fixation of the humeral supracondylar nonunions.

Special Issue on Design, Analysis, and Construction of Segmental Bridges

Special Issue on Design, Analysis, and Construction of Segmental Bridges

Finite element analysis of three commonly used external fixation devices for treating Type III pilon fractures

Pilon fractures are commonly caused by high energy trauma and can result in long-term immobilization of patients. The use of an external fixator i.e. the (1) Delta, (2) Mitkovic or (3) Unilateral frame for treating type III pilon fractures is generally recommended by many experts owing to the stability provided by these constructs. This allows this type of fracture to heal quickly whilst permitting early mobilization. However, the stability of one fixator over the other has not been previously demonstrated. This study was conducted to determine the biomechanical stability of these external fixators in type III pilon fractures using finite element modelling. Three-dimensional models of the tibia, fibula, talus, calcaneus, navicular, cuboid, three cuneiforms and five metatarsal bones were reconstructed from previously obtained CT datasets. Bones were assigned with isotropic material properties, while the cartilage was assigned as hyperelastic springs with Mooney–Rivlin properties. Axial loads of 350N and 70N were applied at the tibia to simulate the stance and the swing phase of a gait cycle. To prevent rigid body motion, the calcaneus and metatarsals were fixed distally in all degrees of freedom. The results indicate that the model with the Delta frame produced the lowest relative micromovement (0.03mm) compared to the Mitkovic (0.05mm) and Unilateral (0.42mm) fixators during the stance phase. The highest stress concentrations were found at the pin of the Unilateral external fixator (509.2MPa) compared to the Mitkovic (286.0MPa) and the Delta (266.7MPa) frames. In conclusion, the Delta external fixator was found to be the most stable external fixator for treating type III pilon fractures.

Experimental verification of a stay cable delta frame model

The accuracy of a finite-element model depends on the assumptions made during modelling. A combined experimental and analytical approach which uses a minimum of expensive instrumentation and construction loading to verify the modelling assumptions and validate the mathematical model was used to study a delta frame on the Veterans′ Glass City Skyway (VGCS). The VGCS is a twin segmental box girder cable-stayed bridge with three lanes in each direction located in Toledo, Ohio. The delta frame is a complex and critical element of the bridge that transfers loads from the box girders to the stay cables. It was instrumented with a sparse array of strain gauges. A small number of strain gauges were placed in regions of expected high strain. The model was calibrated using the prestressing loads and was used to investigate potential cracking during construction of the delta frame and was incorporated in a larger model of the entire bridge. The accuracy of the work was confirmed by inspection for cracking and strain measurements on the completed bridge.

Early Clinical and Radiographic Outcomes after Treatment of Displaced Intra-articular Calcaneal Fractures Using Delta-Frame External Fixator Construct

Intra-articular calcaneal fractures are associated with high morbidity, persistent pain, and long-term disability. This retrospective study assesses early clinical and radiographic postoperative findings of intra-articular calcaneal fractures following treatment by ligamentotaxis using a delta frame construct with a large fragment external fixator. Minimally invasive percutaneous reduction of calcaneal fractures is an alternative treatment for Sanders type II, III, and IV fractures. Ten patients from the Detroit Medical Center were followed between January 2002 and December 2004 for follow-up over a mean of 353.5 ± 85.45 days postoperatively. The mean age of the patients was 45.8 ± 12.3 years. There were 2 patients with Sanders type IIA, 3 patients with type IIIAB, 1 patient with type IIIAC, and 4 patients with type IV fracture patterns. The results demonstrated that the mean calcaneal width decreased, the calcaneal height increased, and the calcaneal length increased when comparing preoperative to postoperative measurements. Böhler’s angle increased from 20.8 ± 8.27° preoperatively to 25.7 ± 5.21° postoperatively, and Gissane’s angle decreased from 127.4 ± 45.22° preoperatively to 111.2 ± 39.38° postoperatively. The posterior facet step-off on CT examination reduced from 2.6 ± 0.82 mm preoperatively to 0.4 ± 0.26 mm postoperatively. The mean postoperative total subtalar joint range of motion was 19.0 ± 4.5° on the affected side and 34.4 ± 4.58° on the contralateral foot. The mean Maryland Foot score was 85.8 ± 6.41 in the 10 patients. With the exception of the change from preoperative to postoperative Böhler’s angle, and the comparison of the ipsilateral (side of the fracture) to contralateral resting calcaneal stance position, all of the comparisons revealed statistically significant ( P ≤ .05) differences. The authors conclude that the delta frame construct is a viable alternative method to open reduction and internal fixation for treating intra-articular calcaneal fractures.

Organic geochemical evaluation of the oil/gas-generative potential of organic matter in Cretaceous strata from the Lower Benue Trough, Nigeria

An analytical procedure involving Rock-Eval pyrolysis of whole-rocks was adopted on fresh outcrop samples covering the three lithostratigraphic units in the Afikpo Basin of the Lower Benue Trough. Three petroleum systems are present in the Cretaceous delta frame: the Asu-River Group, the Eze-Aku Group and proto-Niger Delta sequences. The Afikpo Basin has been correlated to three petroleum systems in the Lower Congo Basin, Niger Delta and the Anambra Basin.

Observations and theory of dispersion in rip currents at the Scripps Pier Bubble Experiment of 1997.

Two of the authors (Caruthers and Stanic), with help and advice from Ralph Goodman, were instrumental in planning and conducting the 1997 Scripps Pier Bubble Experiment. Ralph’s participation was invaluable in making this effort a success. A number of institutions were involved in the overall experiments, but the main experiments, conducted by the Naval Research Laboratory, centered on what was termed the “delta frame” [Caruthers et al., J. Acoust. Soc. Am., 106, 617–625 (1999)]. The delta frame was a triangle 10 m on a side with sources at two apexes and eight hydrophones distributed along the arms. Eight frequencies (39 to 244 kHz) were propagated from the two sources. The NRL personnel and other participants in the experiment published a number of detailed measurements and analyses. In the delta frame experiments, a significant amount of the data was relevant to sound-speed-dispersion analyses. Ralph was always keenly interested in dispersion, but we never fully analyzed, nor published those observations. With that oversight and regret in mind that the relevant analyses were not conducted during Ralph’s lifetime, we have revisited that data in his honor. [Work supported by ONR and NRL.]

Rate scalable video coding technology based on flexible block wavelet

Rate scalable video compression techniques are very attractive, because they are able to encode the video in embedded way that makes the decoding process more flexible to the bandwidth changes. Embedded wavelet coding technology plays an important role in this area. Traditional wavelet transforms are globally optimized. It is very efficient to code the natural images where sudden transitions rarely exist. On the other hand, video compression mostly deals with the differences between adjacent frames, also known as delta frames. Unfortunately, commonly used wavelet transforms are not so efficient on delta frame coding. In this paper, we are presenting a new wavelet coding technique—flexible block wavelet coding (FBWC). It is specially designed for delta frame compression. FBWC not only makes delta frame compression more efficient but also keeps the rate scalability and other scalabilities of wavelet-based scalable video compression techniques. Based on this new delta frame compression technique, we have implemented a highly efficient rate scalable video codec. Its overall performance surpasses the video codec based on set partitioning in hierarchical trees and is comparable to that of H263.

Tomographic reconstruction of shallow water bubble fields

In March of 1997, a shallow water experiment was conducted near the Scripps Pier in La Jolla, CA, USA. The goal was to determine the dynamics, distribution, and acoustic effects of bubbles just offshore from active surf. A major component of the experiment was the "Delta Frame", an apparatus that supported two acoustic sources and eight receivers. Acoustic intensity was measured at frequencies between 39 and 244 kHz over the resulting 16 horizontal ray paths. Paths ranged in length from 2.5 to 8.6 m. In the present paper, a tomography algorithm is developed and implemented using Delta Frame data. Measurements are combined to produce quantitative cross-sectional images of the attenuation associated with the bubble cloud. Numerical simulations predict that the Frame ran resolve details of the field down to about 2 m. Images constructed at different acoustic frequencies are scaled and compared. A 5-min sequence of images is studied in detail. Swell waves are shown to cause rapid fluctuations in the images.