Circular Frame Research Articles

Clinical Faceoff: The Complex Tibial Plafond Fracture: ORIF or Circular External Fixation?

Clinical Faceoff: The Complex Tibial Plafond Fracture: ORIF or Circular External Fixation?

High-speed visualization of soap films bursting dynamics

High-speed (2873 fps) visualization of soap film bursting dynamics has been performed by means of equipment available to a high school laboratory. This paper presents the geometry of the experiment and description of the analysis method of the video frames. We carried out the experiments on the bursting of vertical plane soap films using a circular frame with single central and non-central puncture of the film by a needle. The studies were also performed with simultaneous puncture of the film by two needles. Similar research of the films bursting was done using a non-circular frame in the form of a nonconvex hexagon. In all cases, the rupture line has the shape of a circle. For the first time, the displacement of the circular burst center upwards is recorded and explained. Flapping oscillations of the rupture line border at its movement are confirmed. The oscillating character of the rupture line movement is recorded and explained. In addition, we detected formation of the liquid bridge and its destruction at the interaction of two circular bursts with double puncture of the film.

The use of circular frame external fixation in the treatment of ankle/hindfoot Charcot Neuroarthropathy

Charcot Neuroarthropathy (CN) of the ankle/hindfoot is a devastating condition that results in a loss of alignment, bony malleolar protrusions and frequently leads to ulceration, infection, and amputation. Major limb amputations in this patient population has a 5-year mortality rate approximating 39%–68%. The treatment goal for CN of the ankle/hindfoot is to provide stability with a plantigrade foot that is infection free, shoeable and allows independent weight bearing. The use of a circular frame external fixator is often required when treating patients with CN of the ankle/hindfoot because they often present late with deformity, soft tissue compromise and infection which are contraindications to primary internal fixation. These patients require urgent surgical attention to salvage the limb or risk amputation. In this narrative review article we will discuss the indications, management options, surgical technique, evidence and describe our experience in the use of circular frame external fixation in patients with ankle/hindfoot Charcot Neuroarthropathy.

Treatment of Schatzker Type II-VI Tibial Plateau Fractures by Means of Syndesmotaxis Using an Ilizarov External Fixator and Postoperative CT Evaluation.

IntroductionTibial plateau fractures are more common in young patients following high-energy trauma. In this study, we aim to evaluate the articular surface reduction quality by means of postoperative computer tomography (CT) in Schatzker type II-VI tibial plateau fractures treated with an Ilizarov frame.Materials and methodsThis case series study included 45 patients with a mean age of 39.5 years (range: 18 to 65 years) with a Schatzker type II-VI tibial plateau fracture. The surgical technique was a mini-open reduction of the articular surface impaction followed by application of an Ilizarov circular frame with knee bridging. Pre- and postoperative CT scan evaluation was performed in all of the patients. Outcomes were measured using the American Knee Society Score (AKSS). Mean outpatient follow-up was of at least 12 months (range: 12 to 21 months). Mean time for fracture consolidation was 15.5 weeks (range: 13 to 19 weeks). According to the degree of postoperative articular surface impaction, patients were grouped as follows: 11 had less than 2 mm of depression, 27 had 2 to 4 mm of depression, and 7 over 4 mm of depression.ResultsPatients with articular surface impaction of more than 4 mm presented statistically significant lower values of AKSS compared to those with impaction of lower than 2 mm (p<0.001 ) and 2-4 mm (p<0.001). Patients with joint alignment equal to or more than 5° presented statistically significant lower values of AKSS compared to those with lower than 5°.ConclusionsSchatzker type II-VI tibial plateau fractures may be treated successfully with mini-open reduction and the application of an Ilizarov frame. The increase of articular surface impaction by 1 mm causes reduction of AKSS by 15 units. Patients with joint alignment equal to or more than 5° present lower values of AKSS. The preoperative CT scan is important and useful in planning the surgical intervention no matter the classification system is used.

Cambridge Protocol for Management of Segmental Bone Loss

Introduction:Segmental long bone defects are some of the most challenging to surgically reconstruct; however, there is no clear guidance on which of the myriad of techniques is superior in a given clinical context. We describe three cases of segmental bone loss presenting to a major trauma center and have use these to develop a treatment algorithm for the sub-acute management of such fractures.Case Report:Case 1 - Acute shortening and delayed lengthening using lengthening intramedullary (IM) nail to treat diaphyseal non-union of the femur with associated 3 cm shortening. Case 2 - 15 cm traumatic bone loss of femur, failed Masquelet, treated with IM nail, monolateral external-fixation and cable with a mean lengthening rate of 46 days/cm. Case 3 – 12 cm tibial traumatic bone loss, failed Masquelet, treated with fine wire frame with a mean lengthening rate of 49 days/cm.Conclusion:As our cases illustrate; attempting complicated, definitive management in the acute phase generates complications and necessitates re-intervention. As such, we have developed a treatment algorithm for traumatic segmental bone loss. We recommend waiting 6 weeks and reimaging to check for evidence of spontaneous bone formation before deciding on definitive treatment. First-line treatment for femoral defects <4 cm is acute limb shortening with delayed lengthening using lengthening IM nail. First-line treatment for femoral defects >4 cm is lengthening over nail with monolateral external fixator. First-line treatment of tibial segmental bone defects in our hands is fine wire circular frames which provide excellent scope for soft tissue coverage and deformity correction. Treatment times of over 2 years in a frame are not uncommon and patients must diligently comply with pin sites management and lengthening protocols. This is the first paper providing an algorithm to guide surgeons in choosing the best lower limb reconstruction options in the sub-acute setting; considering the skill set and resources of the center in which one works.

Effect of Model Height and Model Position on Forming Table on Mouthguard Thickness in Thermoforming Using Circular Frame

Effectiveness and safety of mouthguards are greatly affected by its thickness. The aim of this study was to clarify the effect of model height and model position on the forming table on the mouthguard thickness in thermoforming using a circular frame. Mouthguards were thermoformed using 4.0-mm-thick ethylene-vinyl-acetate sheets and a vacuum forming machine. The sheet was sandwiched between circular frames and fixed to the clamp of the forming machine. Working models were two types of hard gypsum models trimmed so that the height of the anterior part was 25 mm (Model A) and 30 mm (Model B). The model was placed with its anterior rim positioned 40 mm (P40), 30 mm (P30), 20 mm (P20), or 10 mm (P10) from the front of the forming table. Differences in the reduction rate of the thickness due to the model height and model positions were analyzed by two-way ANOVA and Bonferroni’s multiple comparison test. Differences depending on the model height were observed at P40 at the incisal edge and P30, P20, and P10 on the labial surface, and the reduction rate of the thickness was significantly smaller in Model A (P < 0.01). As the distance from the model anterior rim to the front of the forming table was smaller, the rate of the thickness of the incisal edge and the labial surface decreases became larger. The rate of decrease in the thickness of the cusp and buccal surface was the smallest at P20. This study indicated that the difference in the thickness of the single-layer mouthguard depending on the model position on the forming table is affected by the model height. However, that is only the anterior part of the mouthguard, and the difference in thickness reduction rate is less than 5%. Additionally, in order to perform stable forming, it is useful to increase the distance from the model to the frame, and it is important to position the part whose thickness is desired to be maintained in the center of the forming table.

‘Lactobacillus sp. strain TERI-D3’, as microbial cell factory for fermentative production of lactic acid’.

This study reports for lactic acid production from different carbohydrates; monosaccharide (glucose, galactose, lactose) & disaccharides (sucrose) and from lignocellulose biomass (rice straw) by a novel strain ‘Lactobacillus sp. strain TERI-D3’. ‘TERI-D3’ strain produced 19.9, 19.4, 18.1 and 15.8 ​g/L of lactic acid from glucose, sucrose, lactose and galactose, respectively. Maximum lactic acid yield efficiency (0.97 ​g/g) was observed with glucose (>95% of the theoretical maximum yield). Lactic acid titer from glucose was 0.41 ​g/L. The lactic acid titer and yield from rice straw biomass sugar was; 11.58 ​g/L and 0.73 ​g/g (>80% of the theoretical maximum yield), respectively. The novelty of this study is that the ‘TERI-D3’ strain is a promising microbe for green lactic acid as it has potential to valorize cheese industry waste, algae biomass as well as to utilize inexpensive next generation lignocellulose biomass that are abundant and do not compete with food chain supply. This approach of recycling and or reuse of organic waste holds importance in the circular economy frame.

On Factors behind the Reasonable Failure Mode of Concrete‐Filled Circular Steel Tubular Composite Frame

As the most basic structure, the concrete‐filled steel tubular (CFST) frame has been widely used in various structures and systems. Compared with conventional reinforced concrete structures and steel structures, CFST structures in strong earthquake showcase more complicated strength and deformation behavior because there are many factors underlying the failure mode. Furthermore, according to the specifications at home and abroad, the corresponding design method to achieve reasonable failure modes for CFST structures has not been clarified. Based on a destructive test on steel beam‐CFST plane frames under constant axial load and lateral load, the fiber mode method and solid element model method are adopted to simulate the failure process of the test frames. Based on finite element model simulations and tests, the fiber model method is proposed to carry out the pushover analysis on the CFST frame structures. The factors behind the reasonable failure mode of steel beam‐concrete‐filled circular steel tubular (CFCST) frame structures are analyzed. Furthermore, the law and influencing factors behind the ratio of flexural capacity of column to beam, the ratio of line stiffness of beam to column, and the ratio of axial compression on the deformation, bearing capacity, and failure modes of the structure are discussed. Some suggestions on the design of reasonable failure mode of steel beam‐concrete‐filled circular steel tubular (CFCST) frame structures are proposed.

Effect of axial dynamization in circular external fixation on bone segment vertical and lateral displacements

Context: The field of deformity correction with external fixation has continued to advance since with the addition of half-pins, even though they can act to stiffen the construct and undermine healing. Dynamization increases axial motion at the fracture site and improves fracture and osteotomy healing in the experimental and clinical studies. No study compares the lateral and vertical displacements of bone segment in dynamized versus nondynamized frames. Aims: The purpose of this study was to compare the segmentary motion in the axial, coronal, and sagittal planes using nondynamized and dynamized circular external fixation frames. Subjects and Methods: Seven frame models were tested including classic Ilizarov three-wire construct and two frame configurations representing the most common modern half-pin and wire combinations. These models were either nondynamized or dynamized with two types of dynamization modules. Each model underwent axial loading up to 50 kg for 11 cycles. Statistical Analysis Used: One-way analysis of variance testing followed by post hoc Tukey's test. Results: The addition of each half pin sequentially decreased axial motion while increased sagittal motion. Dynamization had a limited effect on the sagittal motion but significantly improved axial motion. The sagittal to axial motion ratio increased with half pins in nondynamized frames but decreased equal to or beyond the Ilizarov three-wire fixation frame with dynamization. At the limit of the dynamizers' motion, there was change in the rate of displacement, suggesting that subsequent motion was strictly from the wires and half-pins. Overall, there was minimal coronal motion. Conclusions: While half pins decrease axial micromotion and increase detrimental sagittal motion, dynamization restores.

Biomechanical Analysis of the Behaviour at the Metaphyseal-Diaphyseal Junction of Complex Tibial Plateau Fractures Using Two Circular Fixator Configurations.

BackgroundHigh-energy tibial plateau fractures are challenges in treatment with controversy over operative stabilisation, especially for fractures with metaphyseal–diaphyseal dissociation. Treatment with percutaneous or minimally invasive direct reduction techniques, usually associated with circular external fixation, has generated interest although there is no consensus regarding the type of external fixation to be used.AimThis study aims to compare the two hybrid circular external fixation mountings used to treat the high-energy tibial plateau fractures.MethodsTwo different groups of hybrid circular external fixation frame mountings were assembled using composite tibiae with proximal metaphyseal osteotomies simulating tibial plateau fractures with metaphyseal–diaphyseal dissociation. The standard all-wire frame mounting was assembled, and the comparison frame mounting had the distal K-wires replaced with half-pins. Both groups were tested through cyclic loading between 300 and 1000 N for 10,000 cycles. Interfragmentary linear and rotational displacements were analysed.ResultsThe standard frame mounting behaved similarly to a classic Ilizarov frame, allowing greater axial movement (mean, 3.76 ± 0.26 mm in the standard group and 3.02 ± 0.23 mm in the test group) and smaller mediolateral displacement compared with the test frame (mean, 0.17 ± 0.16 mm compared to 0.56 ± 0.12 mm). The test frame behaved more similarly to a linear external fixator and provided greater axial stability, similar anteroposterior displacement, and lower mediolateral stability. Despite these differences, in both groups the axial displacement was greater than the prejudicial nonaxial movements.ConclusionIncreasing the number of half-pins and decreasing the number of K-wires in hybrid circular external fixation generate frames that tend to behave more similarly to the linear external fixators.How to cite this articleCardoso GS, Amorim R, Penha FM, et al. Biomechanical Analysis of the Behaviour at the Metaphyseal–Diaphyseal Junction of Complex Tibial Plateau Fractures Using Two Circular Fixator Configurations. Strategies Trauma Limb Reconstr 2020;15(3):138–145.

A Staged Approach to Combined Extra-articular Limb Deformity Correction and Total Ankle Arthroplasty for End-Stage Ankle Arthritis.

Patients presenting with end-stage ankle osteoarthritis (OA) in the setting of a concomitant extra-articular limb deformity pose a challenging problem that has not yet been described in the literature. We describe a case series of patients treated with external and internal fixation techniques followed by total ankle arthroplasty (TAA) in a staged approach to treat this complex presentation. Eight patients with limb deformity and end-stage ankle OA who underwent staged deformity correction and TAA from 2016 to 2019 at our institution were retrospectively identified. Average age was 58.5 (range, 49-68) years, with an average follow-up of 2.6 (range, 0.8-4.2) years. All patients underwent limb reconstruction with either tibial osteotomy with a circular frame (n=6) or intramedullary nail (n=2). Limb deformities consisted of the following: posttraumatic tibial malunion (2), limb length discrepancy (1), acquired tibial deformity (1), genu varum (2), or genu valgum (2). Radiographic parameters were assessed pre- and postoperatively on 51-inch standing and ankle radiographs: limb length discrepancy (LLD), genu varum/valgum deformity, recurvatum deformity, mechanical axis deviation, medial proximal tibial angle, lateral distal tibial angle, anterior distal tibial angle, and tibiotalar alignment. Pre- and postoperative patient-reported outcomes were assessed using 2 metrics, the Limb Deformity-Scoliosis Research Society (LD-SRS) and Patient-Reported Outcomes Measurement Information System (PROMIS) scores (Physical Function, Pain Intensity, Pain Interference, Global Physical Function, and Global Mental Function). Following staged limb deformity correction and TAA, all patients achieved correction of LLD and angular deformities of the lower limb, along with restoration of normal alignment of the ankle joint. There was significant mean improvement in all patient-reported LD-SRS and PROMIS domains, except for LD-SRS mental health. LD-SRS function improved from 2.6 (±0.7) to 4.6 (±0.2), P = .008; pain improved from 2.9 (±0.9) to 4.8 (±0.2), P = .012; self-image improved from 2.9 (±0.4) to 4.7 (±0.3), P < .001; and total LD-SRS improved from 3.3 (±0.4) to 4.8 (±0.2), P = .002. Average satisfaction was 4.9 (±0.3). PROMIS physical function improved from 32.3 (±6.8) to 51.3 (±5.3), P = .008; pain interference improved from 66.0 (±9.1) to 41.3 (±6.2), P = .004; pain intensity improved from 60.0 (±13.3) to 33.1 (±5.3), P = .007; global physical health improved from 39.3 (±6.8) to 60.7 (±5.1), P = .002; global mental health improved from 54.8 (±5.9) to 65.6 (±2.8), P = .007. There was one incidence of pin site infection and one reoperation. Deformity correction with either external frame or intramedullary nail fixation followed by TAA in a staged approach was a viable surgical option in the treatment of end-stage ankle OA with concurrent extra-articular limb deformity. This unique approach was capable of achieving deformity correction with improved patient-reported outcomes, minimal complications, and good patient satisfaction. Level IV, retrospective case series.

Combined Internal and External Fixation for Charcot Neuroarthropathy: A Learning Curve

Category:Diabetes; TraumaIntroduction/Purpose:Management of complex foot and ankle deformities secondary to charcot neuroathropathy represents a significant challenge. This is a consequence of medical co-morbidities, vascular disease, peripheral neuropathy, and immune compromise with the surgical challenges of progressive bony defomity and bone resorption. To combat these challenges ‘superconstructs’ have been developed to improve fixation. These aim for fusion beyond the zone of injury with adequate deformity correction all whilst maintaining viability of the soft tissue envelope and mechanical function. This can be achieved with internal fixation using indication specific plates and beaming techniques, external fixation with a circular frame or a combination of the two. The aim of this study was to evaluate of a tertiary referral hospital in the operative management of charcot neuroarthopathy.Methods:This is a retrospective two surgeon case series with all cases jointly operated upon. Cases were identified from a locally held diabetic patient registry as those undergoing charcot foot and ankle reconstruction from 2017 to 2019. No exclusion criteria were outlined. Patient demographics and co-morbidities were collected, pre-op radiological markers (meary’s angle) measured and repeated at 6 weeks and one year. Pre-op radiographs were classifed accroding to brodsky classification. Patient outcomes were recorded of amputation, mortality, ulcer recurrence, reported pain, stable heel, ability to ambulate, need for revision surgery, need for prolonged antibiotics, fusion and surgical complications. PROMS were requested and still awaited at time of submission.Results:Eleven Cases were identified from ten patients, all were included for analysis. Three patients had internal fixation, two had external fixation and six had combined internal with external fixation. Eight patients were Brodsky 1, two patients were Brodsky 3 and one patient was Brodsky 2. Limb salvage was 100% with nil amputations, mortality 0%, ulcer recurrence 0%, 100% improved pain score, and 100% with a stable heel. Meary’s angle improved by a mean of 14o from -16o to -2o at 1 year. Fusion rate determined clinically and radiologically with X-ray was 100% with mean of 129 days and range of (360 - 52). Mean follow-up 454 days and range (547-417). Complications of 2 tibial fractures and 1 deep infection with delayed wound healing.Conclusion:The outcomes of using all three methods is positive with 100% limb salvage, 100% fusion rate, 100% ulcer free and maintenace of Meary’s angle at 1 year post op. We believe that combined internal and external fixation, not widely reported in the literature, is a good option in these cases. The complications reported here were in the first three patients undergoing said technique and represent a learning curve.

Dynamic multi-patch isogeometric analysis of planar Euler–Bernoulli beams

This study presents a novel isogeometric Euler–Bernoulli beam formulation for in-plane dynamic analysis of multi-patch beam structures. The kinematic descriptions involve only displacements of the beam axis, which are approximated by non-uniform rational B-spline (NURBS) curves. Translational displacements of the control points are here considered as control variables. The motivation of this work is to propose a penalty-free method to handle in-plane dynamic analysis of multi-patch beam structures. A simple relation between cross-sectional rotations at the ends of the beams and control variables is derived, allowing the incorporation of the end rotations as degrees of freedom. This improved setting can straightforwardly tackle beam structures with many rigid multi-patch connections, a major challenging issue when using existing isogeometric Euler–Bernoulli beam formulations. Additionally, rotational boundary conditions are conveniently prescribed. Numerical examples with complicated beam structures such as circular arches and frames with kinks are considered to show the accuracy and performance of the developed formulation. The computed results are verified with those derived from the conventional finite element method, and the superior convergence properties of the proposed formulation are illustrated. A possible extension of the present approach to spatial beam structures is discussed.

Investigation Effects of Different Wind Turbine Designs on Air Flow and Generated Power

This paper describes a study of different designs for the wind turbine. The basic wind turbine configuration with a second smaller rotor mounted in the front of the main rotor to extract as much force as possible from the flow. The wind turbine used in all the simulations was an upwind turbine with a 3 MW horizontal axis. The behaviors of pressures, velocities, and power generated were simulated and discussed. Three different configurations have been designed and simulated in SolidWorks at four different wind velocities ranging from 10 to 40 mph with an increment of 10 mph. The results revealed that the power generated by the rotor of the dual turbine to the rotor of the conventional turbine, the power created by the conventional turbine’s rotor is higher even though the size is the same. Furthermore, adding a diffuser equipped with a plat-type circular frame achieved the best performance. Finally, some numbers and figures are highlighted, and a conclusion is stated to summarize the results.

Bone grafting of the regenerate: a previously undescribed case and surgical technique

&lt;p&gt;Distraction osteogenesis can occasionally be complicated with poor-quality regenerated bone. Several factors have been identified in the literature in order to reinforce the maturation of the regenerate. We would like to present a case in a 40 years old patient who presented with shortening and uniplanar varus angulation at his proximal tibia. The patient was treated with distraction osteogenesis using a circular frame. He had significant delay in the maturation of the 4-5 cm gap, and it was decided to use a non-vascularized fibular graft that was introduced using the tibial intramedullary nailing instrumentation. The graft led to an impressive acceleration of the maturation of the regenerate, mostly posteriorly and laterally with poor progression at the anterior part of the tibia. As this is the first such case presented in the international literature it is difficult to speculate why the regenerate was stimulated only in specific areas. Further reporting is necessary to reach safe conclusions.&lt;/p&gt;

Limb lengthening for deformities in Ollier's disease: a systematic review.

The management of limb deformity, shortening, and bone defects in treatment of Ollier's disease is a major challenge. This study aims to summarize and compare the different surgical treatments, and to evaluate the outcome and possible prognostic factors of leg lengthening in these patients. A systematic review of the literature from 1993 to 2017 was performed. Nineteen articles were found including a total of 121 patients with limb deformities because of Ollier's disease. The mean patients' age at the time of first surgery was 12years. A total of 272 segments were surgically treated (14 segments in the upper limbs) with variable techniques including osteotomies and external fixation, intramedullary nails, as well as epiphysiodesis and lengthening over nail. We studied the bone healing index (BHI), distraction index (DI), distraction time, gained length, total treatment time, and complications. Available implants and techniques allowed correction of patients' deformities (lengthening and correction of angular defects) in most cases. External fixators, circular or monolateral frames were the most commonly used technique. The Ilizarov external fixator was the most commonly used frame (196 segments). The BHI was significantly better when the external fixation was combined with intramedullary nails. Epiphysiodesis was most likely to be more associated with the past than to the present. Joint stiffness, infection, early consolidation, pathological fracture, deformity recurrence, delayed union, non-union, neurapraxia, and overlengthening were the reported complications with an overall rate of 27.9%. There is no consensus for the optimal surgical technique and implants for correction of limbs deformities in patients with Ollier's disease. External fixators most commonly circular are the most commonly used implants; however, complications do occur.

Integrated Limb Lengthening Is Superior to Classical Limb Lengthening: A Systematic Review and Meta-analysis of the Literature.

Introduction:Integrated limb lengthening combines both internal and external fixation methods. It has been introduced to improve time to union, patient time in frame, risk of regenerate refracture, and patient function. We systematically review studies to assess whether integrated limb lengthening methods are superior to classic limb lengthening.Methods:A total of 457 patients had classic limb lengthening, whereas 488 underwent integrated limb lengthening. The primary outcome measures were total length achieved (cm), external fixator index (month/cm) and bone healing index (month/cm). Problems, obstacles, and sequelae were compared using random effects meta-analyses of all available cases. Kaplan-Meier curves were generated to compare the time spent in frame.Results:Integrated limb lengthening demonstrated a superior external fixator index (P = 0.0001) and bone healing index (P = 0.0146). The mean time spent in frame for integrated lengthening was significantly shorter (P = 0.0015). Significantly fewer problems (P = 0.000) and sequelae (P = 0.001) were observed with integrated lengthening. Deep infections were more common in the integrated cohort. The lengthening over a nail deep infection rate was significantly higher than with the lengthening and then nailing and lengthening and then plating techniques (P = 0.005).Conclusions:Integrated methods of limb lengthening are superior to classic methods. We suggest the integration of plates and nails with circular frames to improve outcomes in patients undergoing limb lengthening procedures.

Lower limb paediatric trauma with bone and soft tissue loss: Ortho-plastic management and outcome in a major trauma centre

AimWe examined the management and outcome of patients suffering complex paediatric lower limb injuries with bone and soft tissue loss. MethodPatients were identified from our prospective trauma database (2013-2018). Inclusion criteria were age (<18 years) and open lower-limb trauma. We assessed severity of soft tissue and/or bone loss, fracture complexity, surgical techniques and time to surgery. Paediatric quality of life and psychological trauma impact scores (HRQOL and CRIES), Ganga Hospital Injury Severity score (GHISS), union and complication rates were measured. ResultsWe identified 32 patients aged between 4 and 17 years. Twenty-nine patients had open tibia fractures including 14 patients with bone loss, one patient had an open femur fracture, one patient an open talus fracture and one an open ankle fracture with dorsal degloving. Thirty injuries were classified intra-operatively as Gustilo IIIB (or equivalent) and two injuries as Gustilo IIIC. In 10 patients primary skin closure was achieved by acute shortening following segmental bone loss. Twenty-two patients required soft tissue coverage: 17 free vascularised flaps, two fascio-cutaneous flaps and three split skin grafts were used. Two patients required vascular repair. Soft tissue coverage was achieved within 72 hours in 26 patients (81%) and within a week in 30 patients (94%). The surgical techniques applied were: circular fine wire frame (19), monolateral external fixator (4) and open reduction internal fixation (8). Median follow up time was 18 (7-65) months. Paediatric quality of life scores were available in 30 patients (91%) with a median total score of 77.2 out of 100. The psychological trauma impact scores showed one in three patients was at risk of developing post-traumatic stress symptoms (PTSD). The GHISS scores ranged from 6-13. All fractures went on to unite over a median time of 3.8 (2-10) months. Three patients (9%) had major complications; two flap failures requiring revision, one femur non-union requiring revision fixation. ConclusionLimb salvage and timely fracture union is possible in children with complex lower limb trauma. Early intervention providing adequate debridement, skeletal stabilisation and early soft-tissue cover including the option of free microvascular reconstruction in small children when required, delivers acceptable outcomes. A multidisciplinary team approach including clinical psychologists to address the psychological impact of trauma provides optimal holistic care for these children and adolescents. Therefore, treatment for these patients should only be performed in paediatric major trauma centres.

Improving radiographic imaging for circular frames: the Cambridge experience.

Limb reconstruction using circular frames requires complex accurate measurements to achieve correction of mechanical bone axis. Inadequate imaging could ultimately lead to poor clinical outcome. Therefore, radiographs should be obtained in a standardised manner to yield accurate results. Our aim is to improve the effectiveness of post-operative imaging by obtaining precise examinations and improving the accuracy of frame correction; therefore, reducing technical repeats, radiation exposure, time waste in clinic, and achieving cost effectiveness. We implemented a simple technique for obtaining adequate imaging using standard X-ray equipment. This technique was introduced to the radiographers in the radiology department to image patients with circular frames. Images were taken by obtaining a field of view using the X-ray machine cone of light that is orthogonal to the location of interest in both the antero-posterior (AP) and lateral planes. We compared the quality of radiographs, number of repeated X-rays and radiation dose both before and after implementing our protocol RESULTS: We assessed 54 consultations before and 63 consultations after the implementation of our protocol. The results showed a reduction in inadequate radiographs from 78% to 13% department at Addenbrooke's Hospital at a statistical significance of p < 0.00001. In addition, we found a potential radiation dose reduction of 2.7-0.32mSev between the two cohorts. Our results indicate that there would also be a reduction in the cost to the department as well as time spent repeating inaccurate radiographs. We have been able to achieve a significant improvement in the quality of post-operative radiographic imaging and have expanded its use to adult frame patients with a background of traumatic or infectious aetiologies.

Bubble entrainment by a sphere falling through a horizontal soap foam

Processes such as particle separation, froth flotation and explosion suppression rely on the extent to which particles are trapped by foam films. We simulate the quasi-static motion of a spherical particle through a stable, horizontal soap film. The soap film subtends a fixed contact angle, in the range , where it meets the particle. The tension and pressure forces acting on the particle are calculated in two cases: when the film is held within a vertical cylinder, trapping a bubble but otherwise free to move vertically, and when the outer rim of the film is held in a fixed circular wire frame. Film deformation is greater in the second case, and the duration of the interaction therefore increases, increasing the contact time between particle and film. As the soap film returns towards its equilibrium shape following the passage of the particle a small bubble is trapped for contact angles below a threshold value of 90°. We quantify how the size of this bubble increases when the particle is larger and when the contact angle is smaller.