Developments in circular external fixators: a review

Circular external fixators (CEFs) are successfully used in orthopedics owing to their highly favorable stiffness characteristics which promote distraction osteogenesis. Although there are different designs of external fixators, how these features produce optimal biomechanics through structural and component designs is not well known. Therefore, the aim of this study was to conduct a review on CEFs following the PRISMA statement. A search for relevant research articles was performed on Scopus and PubMed databases providing the related keywords. Furthermore, a patent search was conducted on the Google Patent database. 126 records were found to be eligible for the review. Different designs of CEFs were summarized and tabulated based on their specific features. A bibliometric analysis was also performed on the eligible research papers. Based on the findings, the developments of CEFs in terms of materials, automation, adjustment methods, component designs, wire-clamping, and performance evaluation have been extensively discussed. The trends of the CEF design and future directions are also discussed in this review. Significant research gaps include a lack of consideration towards ease of assembly, effective wire-clamping methods, and CEFs embedded with online patient-monitoring systems, among others. An apparent lack of research interest from low-middle and low-income countries was also identified

Correcting angular limb deformities of radius-ulna and tibia in nine dogs using computer-assisted spider frame system

In this study, angular deformities in 9 dogs, including 8 antebrachium and 1 tibia, were corrected using hexapod external fixators with the help of the computer-aided Spider Frame system.Preoperative planning included measurement of craniocaudal and mediolateral angular deformities, rotational deformity, length deficit, as well as determination of the source of the deformity and assembly of the frame.Joint lines and osteotomy/ostectomy lines were determined according to CORA points determined during preoperative measurements. Proximal and distal rings were placed. After the installation of the spider, radial/ tibial osteotomy/ostectomy was performed at the CORA point of the radius/tibia. After the operation, craniocaudal and mediolateral radiographs were taken in all cases. Ring dimensions, angular deformity values (including angulation, translation and rotation) and the degree of shortening were evaluated by radiographs. These data were entered into the web-based Spider software to generate correction prescriptions, after which the length and deformity correction process started on postoperative days 3-5. Functional results were excellent in seven cases and good in the other two cases. Long-term cosmesis was good to excellent in all cases.In conclusion, Spider Frame is a new generation external fixator system with many technical advantages and we recommend its use in appropriate cases

A comparison of the complications and effectiveness of intramedullary limb lengthening

Introduction: Intramedullary limb lengthening to correct congenital or acquired length discrepancy has become a generally accepted concept in reconstructive surgery, but as yet comparative clinical studies are missing, we compared the complications and effectiveness of two types of intramedullary limb lengthening apparatuses. Patients and Methods: In a retrospective series of 303 consecutive patients with internal limb lengthening, we identified 19 matching pairs in terms of predetermined matching parameters (Group A with PRECICE® nail, Group B with Fitbone® nail). All surgeries underwent the sametechnique and every case implemented equivalent pre- and post-operative treatment in patient management. The performance of different implants was estimated by using distraction distance (mm) Distraction Index (DI: quotient between the distraction distance and distraction time (mm/d)), Weight Bearing Index (WBI: quotient from time between the surgery to full weight bearing and distraction distance (d/cm)) and Consolidation Index (CI: quotient from time between surgery to radiological consolidation and distraction distance (d/mm)). Complications were evaluated according to Lee’s classification system for intramedullary lengthening nails. Results: 19 PRECICE® nail patients (Group A) could successfully be matched to 19 Fitbone® nail (Group B) out of 241 Fitbone® nail patients, according to the five aforementioned criteria (1. Equivalent surgical technique and pre- and post-operative treatment protocol; 2. Location of the osteotomy; 3. Simultaneous realignment of the mechanical axis; 4. maximum variation 20% of the lengthening; 5. maximum variation 20% of age). The average age of Group A is 25.7yrs (15-43yrs), The average age of Group B is 25yrs (16-40yrs); the average lengthening in Group A is 34.3mm (20-60mm), and the average lengthening in Group B is 34.1mm (23-55mm). The follow-up of all matched cases averaged 29.5months (14-48months). Viewed separately, the follow-up for the PRECICE® group was 29.5months(16-48months) and for the Fitbone® group 29.4months (14 – 42months).The mean value of Distraction Index in Group A was 0.8mm/d (range: 0.3-1.0 mm/d), and the mean value of Distraction Index in Group B was 0.7mm/d (range:0.2-0.9 mm/d); the mean value of WBI between Group A and Group B differs from 37.7 d/cm (Range: 18.3-62.9 d/cm) to 47.5 d/cm (Range: 20.4-80.7 d/cm); the average value of CI in Group A is 4.8 d/mm (Range: 2.3-9.7 d/mm), as to Group B is 6.9 d/mm (Range: 5.2-9.4 d/mm). The results of paired t-test showed that the DI of Group A was higher than that of Group B, The WBI of Group A was lower than that of Group B, The CI of Group A was lower than that of Group B, all three parameters has statistically significant differences (p＜0.05). By subgrouping the osteotomy sites into proximal femur, distal femur and proximal tibia, we found there were no statistically significant differences among three osteotomy site groups, the p-values of DI、WBI and CI are all bigger than 0.05. After categorizing the patients according to three diagnoses (congenital, acquired and posttraumatic), finding out there were no significant differences of PRECICE® and Fitbone® nail patients in DI, WBI and CI among three diagnostic groups. (Both p＞0.05). According to Lee’s complication system, “Problems” are all unexpected events that can be resolved without surgical intervention. Examples include the formation of a pointed foot that requires physiotherapy treatment. “Obstacles” are incidents that result in one or more surgical interventions, but at the most delay the completion of the treatment and do not endanger the treatment goal. For example, insufficient callus formation, which requires a bone grafting or a re-osteotomy due to premature consolidation of the regenerate. “Sequela” is used in the subsection instead of complications to avoid misunderstanding, which means that results in residual damage after treatment, which lead to the planned distraction distance being missed by more than 10 mm, as well as e.g. an infection of foreign material. There were 8 recorded problems, 4 recorded obstacles and no sequela in Group A patients, and for Group B patients, there were 9 recorded problems, 4 recorded obstacle and no sequela in both matching patients. Conclusions: Specific technical handicaps of the two systems, such as the so-called magnet operated PRECICE® nail and backtracking of the Fitbone® nail seem to bring about the differences in DI, WBI and CI. Aetiology and osteotomy site did not influence as much as the nail differences according to the results of this study. Further comparative studies might engender technical progress and perfection in intramedullary limb lengthening.Einleitung: Die intramedulläre Gliedmaßenverlängerung zur Korrektur angeborener oder erworbener Längendifferenz hat sich in der rekonstruktiven Chirurgie zu einem allgemein akzeptierten Konzept entwickelt. Da jedoch noch keine vergleichenden klinischen Studien vorliegen, haben wir die Komplikationen und die Wirksamkeit von zwei Typen intramedullärer Verlängerungsmarknägel verglichen. Patienten und Methoden: In einer retrospektiven Serie von 303 aufeinanderfolgenden Patienten mit innerer Gliedmaßenverlängerung konnten wir 19 Paare in Bezug auf vorbestimmte passende Parameter (Gruppe A mit PRECICE®-Nagel, Gruppe B mit FITBONE®-Nagel) matchen. Alle Eingriffe wurden mit der gleichen Vorbereitung und Technik durchgeführt und in jedem Fall wurde eine gleichwertige prä- und postoperative Behandlung durchgeführt. Die Leistung von verschiedenen Implantaten wurde anhand des Distraktionsstrecke(mm), des Distraktion Index (DI: Quotient aus Distraktionsstrecke und der Distraktions-Zeit (mm/d)), Weight Bearing Index (WBI: Quotient aus Zeit zwischen Operation bis Vollbelastung und Distraktions-Strecke (d/cm)) und Consolidation Index (CI: Quotient aus Zeit zwischen Operation bis radiologischer Konsolidierung und Distraktions-Strecke(d/mm)) geschätzt. Komplikationen wurden nach Lee´s Klassifikation für die intramedulläre Nagelverlängerung bewertet. Ergebnisse: 19 PRECICE® Nagel-Patienten (Gruppe A) können nach den fünf vorgegebenen Kriterien (1. Äquivalente Operationstechnik und prä- und postoperatives Behandlungsprotokoll; 2. Ort der Osteotomie; 3. Gleichzeitige Neuausrichtung der mechanischen Achse; 4. maximale Variation 20% der Verlängerung; 5. maximale Variation 20% des Alters) erfolgreich mit 19 FITBONE® Nagel (Gruppe B) von 241 Fitbone® Nagel-Patienten abgeglichen werden. Das Durchschnittsalter der Gruppe A beträgt 25,7 Jahre (15-43 Jahre). Das Durchschnittsalter der Gruppe B beträgt 25,0 Jahre (16-40 Jahre). Die durchschnittliche Distraktionsstrecke beträgt in Gruppe A 34,3 mm (20-60 mm) und in Gruppe B 34,1 mm (23-55 mm). Das Follow-Up aller übereinstimmenden Fälle beträgt durchschnittlich 29,5 Monate (14-48 Monate). Separat betrachtet beträgt das Follow-Up für die PRECICE®-Gruppe 29,5 Monate (16-48 Monate) und für die Fitbone®-Gruppe 29,3 Monate (14 - 42 Monate). Der Mittelwert von DI ist in Gruppe A 0,79 mm/d (Bereich: 0,30 bis 0,97 mm/d) in Gruppe B ist 0,67 mm/d (Bereich: 0,23 bis 0,91 mm/d). Der Mittelwert des WBI zwischen Gruppe A und Gruppe B unterscheidet sich von 37,7 d / cm (Bereich: 18,3-62,9 d/cm) bis 47,5 d / cm (Bereich:20,3-80,7 d/cm); Der Durchschnittswert von CI in Gruppe A ist 4,8 d/mm (Bereich: 2,34 bis 9,71 d/mm), während für Gruppe B 6,87 d/mm (Bereich: 5,16 bis 9,44 d/mm) gilt. Die Ergebnisse des gepaarten t-Tests zeigen, dass der DI von Gruppe A höher war als der von Gruppe B, der WBI von Gruppe A niedriger als der von Gruppe B, der CI von Gruppe A niedriger als der von Gruppe B, und alle drei Parameter weisen statistisch signifikante Unterschiede auf (p＜0,05). Bei der Untergruppierung der Lokalisation der Osteotomien in proximales Femur, distales Femur und proximale Tibia fanden sich keine statistisch signifikanten Unterschiede zwischen drei Lokalisationen. Die p-Werte von DI, WBI und CI sind alle größer als 0,05. Nach Kategorisierung der Patienten nach drei Diagnosen (angeboren, erworben und posttraumatisch längen Differenz) ergab sich kein signifikanter Unterschied zwischen PRECICE®- und Fitbone®-Nagelpatienten bei DI, WBI und CI zwischen drei Diagnosegruppen. (beide p＜0,05) Die Auswertung der Komplikationen und Probleme nach Lee’s Klassifikation „Probleme“ sind alle unerwarteten Ereignisse, die ohne chirurgischen Eingriff behoben werden können. Beispiele hierfür sind die Bildung eines spitzen Fußes, der eine physiotherapeutische Behandlung erfordert. „Hindernisse“ sind Vorfälle, die zu einem oder mehreren chirurgischen Eingriffen führen, jedoch den Abschluß der Behandlung höchstens verzögern und das Behandlungsziel nicht gefährden. Zum Beispiel unzureichende Kallus Bildung, die eine Knochentransplantation oder eine Reosteotomie aufgrund einer vorzeitigen Konsolidierung des Regenerats erfordert. „Weiteren Folgen“ bedeutet, dass nach der Behandlung Restschäden auftreten, die dazu führen, dass der geplante Distraktionsabstand um mehr als 10 mm verfehlt wird, z. eine Infektion mit Fremdmaterial. Es gab 8 aufgezeichnete „Probleme“, 4 aufgezeichnete „Hindernisse“ und keine „weiteren Folgen“ bei Patienten der Gruppe A. Und bei Patienten der Gruppe B gab es 9 aufgezeichnete „Probleme“, 4 aufgezeichnete „Hindernisse“ und ebenso keine „weiteren Folgen“. Fazit: Spezifische technische Nachteile der beiden Systeme, wie ein gelegentliches, unkontrolliertes Rücklaufen des Fitbone®-Nagels, scheinen die Unterschiede in DI, WBI und CI hervorzurufen. Die Ätiologie der Beinlängendifferenzen und die Lokalisation der Osteotomie verursachen keine signifikanten Unterschiede im Ergebnis der beiden Implantate. Weitere, größere klinische Vergleichsstudien könnten zu technischem Fortschritt und weiterer Perfektionierung bei der intramedullären Gliedmaßenverlängerung führen

Development and application features of 3-d atlas of transosseous elements positions for pre-surgery planning of the shin bones osteosynthesis

КОНЕЧНОСТИ НИЖНЕЙ ТРАВМЫЛОДЫЖКИ ПОВРЕЖДЕНИЯГОЛЕНОСТОПНОГО СУСТАВА ПОВРЕЖДЕНИЯПЕРЕЛОМЫ КОСТЕЙ ГОЛЕНИПЕРЕЛОМА ИММОБИЛИЗАЦИЯ ВНУТРЕННЯЯОСТЕОСИНТЕЗ ПЕРЕЛОМАЧРЕСКОСТНЫЙ ОСТЕОСИНТЕЗПРЕДОПЕРАЦИОННОЕ ВЕДЕНИЕ БОЛЬНОГОПРЕДОПЕРАЦИОННЫЙ ПЕРИОД, ВЕДЕНИЕПРЕДОПЕРАЦИОННЫЙ ЭТАП ЛЕЧЕНИЯПРЕДОПЕРАЦИОННОЕ ПЛАНИРОВАНИЕКОМПЬЮТЕРНОЕ МОДЕЛИРОВАНИЕТРЕХМЕРНАЯ МОДЕЛЬЦель. Оптимизировать процесс предоперационного планирования чрескостного остеосинтеза при переломах костей голени путем разработки и применения 3-D атласа позиций чрескостных элементов. Материал и методы. На основе поперечных компьютерных томографических сканов интактной нижней конечности взрослого человека, с помощью программного пакета 3-D Doctor в автоматическом режиме, созданы трехмерные имитационные модели костей голени и окружающих их мягкотканных структур. Данные модели экспортированы в программный комплекс Autodesk Inventor 11. В режиме Part Modeling проведено разделение модели мягкотканных структур голени на 96 частей – сегментов, соответствующих позициям для проведения чрескостных элементов согласно методу унифицированного обозначения чрескостного остеосинтеза, и их сохранение в отдельных файлах. В режиме "Assembly" программы проведена сборка сегментов голени. Результаты. Предложен алгоритм действий для создания 3-D атласа позиций для проведения чрескостных элементов, согласно которому в программе Autodesk Inventor 11 созданы трехмерные имитационные модели систем "голень – аппарат внешней фиксации" и проведен анализ их возможностей по предоперационному планированию чрескостного остеосинтеза. В результате проведенного исследования установлено, что использование 3-D атласа позиций обеспечивает возможность выбора оптимальной конструкции и наиболее рациональной, в каждой конкретной клинической ситуации, компоновки аппарата внешней фиксации; определения количества и оптимальных уровней расположения опор; выбора типа и наиболее целесообразных мест проведения чрескостных элементов. Заключение. Применение 3-D атласа позиций чрескостных элементов позволяет вплотную приблизиться к решению вопроса предоперационного планирования с позиций комплексного подхода: адекватного существующей клинической ситуации выбора типа аппарата внешней фиксации, его компоновки, определения количества чрескостных элементов, направлений и плоскостей их проведения, что позволит значительно уменьшить количество технических ошибок, обеспечит снижение рисков возникновения осложнений и будет способствовать достижению положительных анатомо-функциональных результатов в подавляющем большинстве клинических случаев.Objective. To improve the pre-surgery planning of transosseous osteosynthesis in the shin bone fractures by developing and applying the 3-D atlas of transosseous elements positions. Methods. On the basis of transverse computer tomographic scans of the intact lower limb of an adult using the 3-D Doctor software package, three-dimensional simulation models of the shin bones and surrounding soft tissue structures were created in the automatic mode. These models were exported as separate files into the Autodesk Inventor 11 software package. In Part Modeling mode, the division of the model of the soft tissue structures of the shin into 96 parts was carried out - the segments corresponding to the positions for passing the transosseous elements according to the method of the unified marking of transosseous osteosynthesis and their preservation in separate files. In Assembly mode, the assemblage of the shin segments has been performed. Results. The algorithm for the creation of 3-D atlas of transosseous elements positions was proposed, according to which the three-dimensional simulation models of the "shin - external fixation device" system were created in the Autodesk Inventor 11 program and the analysis of their possibilities regarding pre-surgery planning of transosseous osteosynthesis was conducted. As a result of the research, it was found out that the use of the 3-D atlas of positions provides an opportunity for selecting the optimal design and the most efficient layout of the external fixation device in each particular clinical situation; determination of the number and optimal layout levels of the supports; the choice of the type and the most appropriate places for passing of the transosseous elements. Conclusions. The application of 3-D Atlas of transosseous elements positions permits to approach the solution of the problem of pre-surgery planning from the standpoint of an integrated approach to choosing the type of external fixation device that is adequate to the existing clinical situation, its layout, determining the number of transosseous elements, directions and planes for passing them, which will allow reducing significantly the number of technical errors, reducing the risk of complications and promoting the achievement of positive anatomical and functional results in the vast majority of clinical cases

Foot Deformity Correction with Hexapod External Fixator, the Ortho-SUV Frame™

External fixators enable distraction osteogenesis and gradual foot deformity corrections. Hexapod fixators have become more popular than the Ilizarov apparatus. The Ortho-SUV Frame™ (OSF; Ortho-SUV Ltd, St. Petersburg, Russia), a hexapod that was developed in 2006, allows flexible joint attachment such that multiple assemblies are available. We assessed the reduction capability of several assemblies. An artificial bone model with a 270-mm-long longitudinal foot was used. A 130-mm tibial full ring was attached 60 mm proximal to the ankle joint. A 140-mm, two-third ring forefoot was attached perpendicular to the metatarsal bone axis. A 130-mm, two-third ring hindfoot was attached parallel to the tibial ring. A V-osteotomy, which was combined with 2 oblique osteotomies at the navicular-cuboid bone and the calcaneus, was performed. The middle part of the foot, including the talus, was connected to the tibial ring. We assessed 5 types of forefoot applications and 4 types of hindfoot applications. The range of correction included flexion/extension in the sagittal plane, adduction/abduction in the horizontal plane, and pronation/supination in the coronal plane. Additionally, we reported the short-term results in 9 clinical cases. The forefoot applications in which the axis of the hexapod was parallel to the axis of the metatarsal bones had good results, with 52°/76° for flexion/extension, 48°/53° for adduction/abduction, and 43°/51° for pronation/supination. The hindfoot applications in which the hexapod encircled the ankle joint also had good results, with corresponding values of 47°/58°, 20°/35°, and 28°/31°. Clinically, all deformities were corrected as planned. Thus, multiple assemblies and a wide range of corrections are available with the OSF. © 2013 American College of Foot and Ankle Surgeons

Unexpected case of ankle tuberculosis in a young professionals leading to delay in diagnosis

We report a case of a 38 year-old engineer presented with left ankle pain for 2 years and initially treated as gouty arthritis because of high serum uric acid. A year later his left ankle become swollen and plain radiograph showed soft tissue swelling around the ankle with normal articular surface and bone. An MRI investigation reported as gouty arthritis of ankle with tophi. While on treatment for gouty arthritis, he developed pus discharge from the swelling. The ankle pain also worsen and he was unable to weight bear on the affected leg. An incision and drainage shown pus from the ankle joint which grew pseudomonas aeruginosa. He was treated with intravenous followed by oral ciprofloxacin 250 mg bd. However his condition does not improved and a month after antibiotic treatment a repeated radiograph shows narrowing of joint space with irregular cortical destruction, osteopenic bone . suggestive of worsening of his septic arthritis. During this period he deny of having any fever, cough or night sweats. However he did notice some loss of weight and loss of appetite. He has worked in Africa and Russia before in petroleum industry. After 4 months of antibiotic and no sign of improvement, a biopsy and repeat culture was taken from the ankle which reveal tuberculous arthritis and positive for AFB culture. A plain chest radiograph revealed miliary tuberculosis picture. He was started on a anti TB treatment and the wound healed after a few weeks. After 4 months of treatment he was able to walk without support with reduce ankle range of motion. This case illustrate that the diagnosis was delay because tuberculosis was not suspected in a young professionals with ankle pain and elevated serum uric acid level. Further delay in diagnosis because MRI report also suggestive of gouty tophi and the pus culture and sensitivity grew pseudomonas aeruginosa

Development of a Personalised 3D Mandibular Distraction Device for the Management of Craniofacial Microsomia

Introduction: Surgical correction of the facial skeleton in deformity has evolved significantly over the recent past as techniques and technology have improved. Where there exist significant skeletal discrepancies, large skeletal changes are required and there remains a need to further improve upon our current standard to achieve these surgical goals. Distraction osteogenesis (DO) is a technique that induces bone formation without the need for bone grafting and allows for guided shape change in addition to expanding the overlying tissue envelope. Current mandibular distractors are limited as they are bulky; there are wound problems related to the external siting of the actuator; there is a limited geometry of possible distraction; the final result is unpredictable; they function in a discontinuous rather than continuous motion and they require daily winding by the patient. There exists a clear potential benefit to patients should these drawbacks be overcome. Aim: The aim of the project is to design a novel device to modify the shape of the deformed jaw to a prescribed, predetermined shape that is specific to the patient and that does not require external manipulation. Methods: The mechanical properties of helical springs constructed from a nonlinear material were tested to review their suitability for use as actuators to deliver force in a fully buried continuous distractor. A finite element model was then created to generalise the concept for use where different forces may be required. Lastly a prototype was designed and empirically tested ex-vivo to assess whether the aims of the project were fulfilled. Results: The nonlinear material was found to deliver adequate, continuous and relatively constant force over a distance in keeping with DO. The finite element model was demonstrated to accurately represent the empirical properties of the helical spring. The prototype designed was able to modify the shape of a deformed jaw to a predetermined position without requiring external manipulation in a surgical model. Discussion: This project develops and tests a prototype that is fully buried and can achieve multiplanar continuous DO without the need for patient involvement and therefore provides novel technology as a solution to improving practice

The effect of leg lengthening surgery on muscle function : implications for rehabilitation

Limb length discrepancy is a common orthopaedic problem, frequently requiring surgical intervention. This thesis is concerned with one method of limb equalisation, leg lengthening surgery. It investigates the effect of leg lengthening surgery on the muscle function and rehabilitation of patients. Qualitative research methodologies demonstrated that there is considerable uncertainty about the best physiotherapy management of patients treated by the Ilizarov method. There is little evidence-basedre search into the rehabilitation of patients treated by this method of surgery. A clinical cohort study was conducted which examined different aspects o f rehabilitation. These included the effects of leg lengthening surgery on joint range of motion, muscle strength and on the ability to perform functional activities. The study of the effect of surgery on joint range of motion highlighted the need for repeatable measurement techniques. It found that there was a significant loss of joint range of motion in the latent period prior to distraction of the bones starting. Factors that influenced loss of joint range in the subjects included in this study included the rate of lengthening, the age and the diagnosis of the patient. A mathematical model was developed to assist in predicting the loss of joint range, at the pre-operative examination. The ability to perform functional activities and the effect on muscle strength were investigated and found to recover for up to 2 years following surgery and the removal of the Ilizarov fixator. Muscle strength recovered to within 5% of the baseline value by 2 years. This emphasises the need for a prolonged period of rehabilitation for patients treated by this method of surgery. Finally a Delphi survey was conducted to produce Clinical Guidelines about the physiotherapy management of patients treated by the Ilizarov method