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Dhaniwala N, Jadhav S, Chirayath A, Saoji A. Ilizarov Ring Fixator in the Lower Limb for 2000 Days: A Case Report. Cureus 2023; 15:e43891. [PMID: 37746386 PMCID: PMC10511823 DOI: 10.7759/cureus.43891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 08/21/2023] [Indexed: 09/26/2023] Open
Abstract
Ring external fixators developed by Gavriil Abramovich Ilizarov from Russia are used to treat the difficult cases of infected non-union, shortening of limbs by bone lengthening, and deformity correction in joints and bones in isolation or in combination. Fixation of the involved bone with the ring is commonly achieved using four rings, each having two Ilizarov wires that are passed along the superior surface of the ring, then across the bone, and exiting out on the opposite side touching the surface of the ring. The case report herein reports a patient who kept the ring fixator on his thigh without any problem for a long period of five and a half years. The case is being reported due to the abnormally long period of ring fixator application without any complications and the excellent result achieved in terms of union and infection control.
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Affiliation(s)
- Nareshkumar Dhaniwala
- Department of Orthopaedic Surgery, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Shivshankar Jadhav
- Department of Orthopaedic Surgery, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Aditya Chirayath
- Department of Orthopaedic Surgery, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Amit Saoji
- Department of Orthopaedic Surgery, Datta Meghe Institute of Higher Education and Research, Wardha, IND
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Hutchinson B. Circular Fixation in Charcot. Clin Podiatr Med Surg 2022; 39:643-658. [PMID: 36180194 DOI: 10.1016/j.cpm.2022.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Static circular fixation is a valuable tool for patients with Charcot foot and ankle deformities. The versatility of circular fixators allows for dynamic adjustments over time and can allow for off-loading of flaps or ulcers. The circular fixator can be used as a primary fixation device in cases of osteomyelitis or to facilitate lengthening when a segmental bone defect exists such as loss of the talus. As a secondary fixation device it can protect the internal fixation or be used when there is a compromised soft tissue envelope.
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Affiliation(s)
- Byron Hutchinson
- CHI/Franciscan Advanced Foot & Ankle Fellowship, Franciscan Foot & Ankle Associates: Highline Clinic (Part of Franciscan Medical Group), 16233 Sylvester Road SW G-10, Seattle, WA 98166, USA.
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Bonardi A, Rovesti GL, Martini FM, Dondi F, Benedini D, Barbieri F. Comparison between Areas of Bone Visualization Using Radiolucent Hybrid Fixator Frames and Graphically Simulated Metallic Frames: An Ex Vivo Study. Vet Sci 2022; 9:vetsci9030120. [PMID: 35324848 PMCID: PMC8951392 DOI: 10.3390/vetsci9030120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 02/22/2022] [Accepted: 03/04/2022] [Indexed: 02/05/2023] Open
Abstract
The objective of this study is to evaluate the difference between the amount of bone visible with the superimposition of a radiolucent hybrid external fixator and a graphically simulated metallic frame. Eighteen frames were applied to eighteen bone specimens. The fracture area (FA), the radiolucent area (RLA) and the radiopaque area (ROA) inside the FA were calculated for each construct on both postoperative views. The ratio between the RLA and FA and between the ROA and FA was used to evaluate the amount of bone visible in the FA with a radiolucent and a radiopaque fixator, respectively. Finally, the areas of RLA and ROA were compared using the Wilcoxon test and Friedman test to evaluate the effect of the radiolucent material on the amount of bone visible. Differences were considered significant if p < 0.5. In every specimen p was <0.5. The amount of bone visible was significantly higher with the radiolucent frame compared to the radiopaque frame. Based on the results of this study, the use of radiolucent materials can be a valuable option for external fixation, in order to decrease the radiographic interference of the frame, allowing better assessment of fracture reduction and bone healing on postoperative radiographs.
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Affiliation(s)
- Andrea Bonardi
- Ortovet stp srl, Piazza Alessandrini 2/D, 43036 Fidenza, Italy;
| | - Gian Luca Rovesti
- Clinica Veterinaria M. E. Miller, Via della Costituzione 10, 42025 Cavriago, Italy;
| | - Filippo Maria Martini
- Department of Veterinary Science, University of Parma, Via del Taglio 10, 43126 Parma, Italy;
| | - Francesco Dondi
- Department of Veterinary Medical Sciences, Alma Mater Studiorum, University of Bologna, Via Tolara di Sopra 50, 40064 Ozzano dell’Emilia, Italy;
| | - Davide Benedini
- Ambulatorio Veterinario Dr. Lelio Benedini, Viale dell’Industria 97, 36071 Arzignano, Italy
- Correspondence: ; Tel.: +39-3493555415
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Chau L, Wilson L. Pes varus correction in dachshunds with mini hybrid external skeletal fixators. Aust Vet J 2021; 100:135-145. [PMID: 34907526 DOI: 10.1111/avj.13139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 10/15/2021] [Accepted: 11/30/2021] [Indexed: 11/29/2022]
Abstract
AIM To evaluate the clinical and radiographic outcome of pes varus deformity correction in dachshunds managed with acute medial opening wedge osteotomy of the distal tibia and stabilised with a mini hybrid external skeletal fixator (HESF). METHODS Surgical correction involved a transverse osteotomy over the premeasured location at the distal tibia and application of a IMEX mini HESF. All corrections were evaluated using centre of rotation and angulation methodology. RESULTS Medical records and radiographies of 20 dachshunds (28 pes varus corrections) were reviewed. All osteotomies healed and fixators were removed between 6 and 12 weeks. Lameness resolved in 18 dachshunds (90%) and significantly improved in two dachshunds (10%). Lateral patella luxation (LPL) was detected in 11/28 (39.2%) of the involved pelvic limbs, all of which resolved following pes varus correction. Mean frontal plane alignment (FPA) of the normal and abnormal tibiae were 12.3° valgus (range: 4°-18°) and 25° Varus (range: 16°-41°) respectively. Angular correction ranged between 30° and 50° (Mean: 39°) and the mean post-operative FPA was 13° valgus (range: 5°-21°). CLINICAL SIGNIFICANCE Pes varus deformity in dachshunds can be corrected by medial opening wedge osteotomy of the distal tibia stabilised by HESF. Single-session bilateral pes varus corrections can also be performed with minimal morbidity. LPL was commonly detected in dogs with pes varus deformity and all resolved spontaneously following pes varus correction alone.
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Affiliation(s)
- L Chau
- Veterinary Specialist Service, Carrara, Queensland, 4211, Australia
| | - L Wilson
- Animal Referral Hospital, Centenary Technology Park, Sinnamon Park, Queensland, 4073, Australia
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Thiart G, Herbert C, Sivarasu S, Gasant S, Laubscher M. Influence of Different Connecting Rod Configurations on the Stability of the Ilizarov/TSF Frame: A Biomechanical Study. Strategies Trauma Limb Reconstr 2020; 15:23-27. [PMID: 33363637 PMCID: PMC7744669 DOI: 10.5005/jp-journals-10080-1447] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Aim The Ilizarov external fixator (IEF) is frequently used in trauma and elective orthopaedics. Many of its biomechanical variables (ring size, wire diameter, wire number, half pins vs wires, etc.) and their influence on stability and stiffness have been investigated. There is, however, a paucity in the literature regarding the influence of the connecting rod numbers and configurations between the rings on IEF stability. The primary aim of this biomechanical study was to compare the stability between four- and three-rod IEF configurations. Secondarily to assess the difference in stability between symmetrical and asymmetrical spacing of the IEF rods. Materials and methods A custom jig was designed to facilitate mounting of a basic two-ring IEF in a hydraulic press. Controlled centre and off-centre (thus simulated bending) axial loading was then applied across the frame. The configurations were loaded up to 4,000 N. The frame deformation was plotted and the data were then analysed and interpreted. Results Negligible differences were observed between different four- and three-rod configurations as long as the applied force at the loading point (LP) was within the area of support (AOS) created by the rods. The different four-rod constructs were always more stable than the three-rod constructs during bending. Conclusion There is comparable stiffness between a four-rod and a three-rod IEF construct as long as the LP is within the AOS created by the rods. A four-rod IEF is stiffer than a three-rod IEF in bending. Clinical significance This study will possibly change some paradigms regarding the planning and application of IEFs by Orthopaedics Traumatologists and Reconstruction Surgeons. How to cite this article Thiart G, Herbert C, Sivarasu S, et al. Influence of Different Connecting Rod Configurations on the Stability of the Ilizarov/TSF Frame: A Biomechanical Study. Strategies Trauma Limb Reconstr 2020;15(1):23–27.
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Affiliation(s)
- Gerhard Thiart
- Department of Orthopaedics, Worcester Provincial Hospital, Worcester, Western Cape, South Africa; Department of Orthopaedic Research, Groote Schuur Hospital Unit, University of Cape Town, Cape Town, Western Cape, South Africa
| | - Christopher Herbert
- Department of Biomechanical Engineering, University of Cape Town, Cape Town, Western Cape, South Africa
| | - Sudesh Sivarasu
- Department of Biomechanical Engineering, University of Cape Town, Cape Town, Western Cape, South Africa
| | - Saadiq Gasant
- Department of Biomechanical Engineering, University of Cape Town, Cape Town, Western Cape, South Africa
| | - Maritz Laubscher
- Department of Orthopaedic Research, Groote Schuur Hospital Unit, University of Cape Town, Cape Town, Western Cape, South Africa
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Kani KK, Porrino JA, Chew FS. External fixators: looking beyond the hardware maze. Skeletal Radiol 2020; 49:359-374. [PMID: 31515594 DOI: 10.1007/s00256-019-03306-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 08/25/2019] [Accepted: 08/27/2019] [Indexed: 02/02/2023]
Abstract
External fixation has a wide variety of orthopedic applications. Although external fixator frames may have a complex appearance, these constructs are formed from several basic components and can be broadly categorized into unilateral, circular, or hybrid designs. The introduction of computer-aided circular external fixation devices (hexapod frames) has simplified the treatment of multiaxial and especially rotational deformities. Serial radiography plays a central role in the evaluation of callus formation (at the level of treated fracture or nonunion as well as the regenerate and docking site with distraction osteogenesis), tailoring the rate and rhythm of distraction during distraction osteogenesis, evaluation of frame complications, and determination of the timing of frame removal. The goals of this article are to review: the components, types, and relevant terminology of external fixator constructs with special emphasis on the Taylor spatial frame, the principles and techniques of distraction osteogenesis, and complications of external fixation.
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Affiliation(s)
- Kimia Khalatbari Kani
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Jack A Porrino
- Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, 06520-8042, USA
| | - Felix S Chew
- Department of Radiology, University of Washington, 4245 Roosevelt Way NE, Box 354755, Seattle, WA, 98105, USA
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7
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Comparison of the axial stiffness of carbon composite and aluminium alloy circular external skeletal fixator rings. Vet Comp Orthop Traumatol 2017; 26:172-6. [DOI: 10.3415/vcot-12-03-0047] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 12/23/2012] [Indexed: 11/17/2022]
Abstract
SummaryObjectives: The purpose of this study was to compare the axial stiffness of aluminium alloy and carbon composite single-ring constructs.Methods: Single-ring constructs were made with rings of different material compositions (aluminium alloy and carbon composite), diameters (55 mm, 85 mm, and 115 mm), and thicknesses (6 mm for the single-ring, 12 mm for the double-ring) with all other components remaining constant. Stiffness of each construct was determined under loading in axial compression with a materials testing machine. The axial stiffness of each group was compared using a three-factor factorial analysis of variance investigating all main effects and interactions between ring diameter, ring thickness, and ring material composition; p <0.05 was considered significant.Results: Carbon composite constructs were 16-55% as stiff as corresponding aluminium alloy constructs. Within each combination of ring material composition and ring diameter, stiffness did not significantly increase when the ring thickness was doubled. Within each combination of ring material composition and ring thickness, stiffness significantly decreased with increased ring diameter.Clinical significance: Aluminium alloy rings were found to be significantly stiffer than carbon composite rings. Although the carbon composite rings were considerably less stiff, clinical recommendations cannot be made from a single-ring in vitro analysis. Further studies are needed to evaluate the behaviour of these rings in vivo.
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Bierens D, Unis MD, Cabrera SY, Kass PH, Owen TJ, Mueller MG. Radius and ulna fracture repair with the IMEX miniature circular external skeletal fixation system in 37 small and toy breed dogs: A retrospective study. Vet Surg 2017; 46:587-595. [PMID: 28370231 DOI: 10.1111/vsu.12647] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 10/27/2016] [Accepted: 11/02/2016] [Indexed: 11/27/2022]
Affiliation(s)
| | - Marcos D. Unis
- LeadER Animal Specialty Hospital, Department of Surgery; Cooper City Florida 33024
| | - Sady Y. Cabrera
- Southern California Veterinary Specialty Hospital, Department of Surgery; Irvine California 92614
| | - Philip H. Kass
- School of Veterinary Medicine, University of California, Department of Population Health and Reproduction; Davis California 95616
| | - Tina J. Owen
- College of Veterinary Medicine-Small Animal Surgery Department; Washington State University; 205 Ott Road Pullman Washington 99164
| | - Maureen G. Mueller
- VCA West Los Angeles Animal Hospital-Surgery Department; 1900 S. Sepulveda Blvd Los Angeles California 90025
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Lewis RA, Lewis DD, Anderson CL, Hudson CC, Coggeshall JD, Iorgulescu AD, Banks SA. Mechanics of Supplemental Drop Wire and Half-Pin Fixation Elements in Single Ring Circular External Fixator Constructs. Vet Surg 2016; 45:471-9. [PMID: 27009685 DOI: 10.1111/vsu.12467] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 12/08/2015] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Evaluate the effects of supplemental fixation elements on the mechanical properties of a single ring circular fixator construct. STUDY DESIGN In vitro mechanical testing. SAMPLE POPULATION Five construct configurations (six replicates of each configuration) were used to stabilize a 1.6 cm diameter Delrin rod bone model. METHODS Constructs were assembled using 66 mm complete rings, 1.6 mm olive wires, and 3.2 mm diameter half-pins. Construct configurations tested were a base single ring construct, constructs with 1 supplemental drop wire or constructs with 1, 2, or 3 supplemental half-pins. Constructs were loaded in axial compression, caudocranial and mediolateral bending, and torsion. Strain was measured in individual fixation elements during axial loading. RESULTS A supplemental drop wire or half-pin significantly increased bending and torsional stiffness. The supplemental half-pin increased caudocranial stiffness significantly more than placing a drop wire. Placing a 2nd or 3rd pin afforded significantly greater increases in construct stiffness in all modes of loading, with 3 half-pin constructs having significantly greater axial and caudocranial stiffness than 2 half-pin constructs. Placing a single supplemental pin induced cantilever bending resulting in angular displacement of the Delrin rod during axial loading and high strain in both the fixation wire secured distal to the ring and the pin. Supplemental half-pins incrementally reduced strain in all fixation elements and resulted in linear displacement of the Delrin rod during axial loading. CONCLUSION If using supplemental half-pins as fixation elements, insertion of 2 or 3 pins is preferred over a single pin.
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Affiliation(s)
- Ryan A Lewis
- Comparative Orthopaedics and Biomechanics Laboratory, University of Florida, Gainesville, Florida
| | - Daniel D Lewis
- Comparative Orthopaedics and Biomechanics Laboratory, University of Florida, Gainesville, Florida.,Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Christopher L Anderson
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida.,Department of Mechanical and Aerospace Engineering, College of Engineering, University of Florida, Gainesville, Florida
| | - Caleb C Hudson
- Comparative Orthopaedics and Biomechanics Laboratory, University of Florida, Gainesville, Florida.,Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, Florida
| | - Jason D Coggeshall
- Comparative Orthopaedics and Biomechanics Laboratory, University of Florida, Gainesville, Florida
| | - Alex D Iorgulescu
- Comparative Orthopaedics and Biomechanics Laboratory, University of Florida, Gainesville, Florida
| | - Scott A Banks
- Comparative Orthopaedics and Biomechanics Laboratory, University of Florida, Gainesville, Florida.,Department of Mechanical and Aerospace Engineering, College of Engineering, University of Florida, Gainesville, Florida
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Tresley J, Schoenleber SJ, Singer AD, Clifford P. "Ilizarov" external fixation: what the radiologist needs to know. Skeletal Radiol 2015; 44:179-95. [PMID: 25223361 DOI: 10.1007/s00256-014-2001-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 08/30/2014] [Indexed: 02/02/2023]
Abstract
Circular external fixation, including the Ilizarov method, is a complex and often long-term treatment used for various orthopedic conditions. Due to the complexity of the hardware, frequent postoperative complications, and the potential for significant radiographic changes between visits, it is important for the radiologist to have a basic understanding of ring fixators. This publication reviews indications for external fixation versus internal fixation and whether to use a circular or uniplanar construct if external fixation is elected. Indications for and characteristics of static circular frames, intercalary and non-intercalary transport frames, and deformity circular frames will also be discussed. While general similarities exist between frame types, each has unique components of which the radiologist must be aware. An emphasis is placed on the important features and complications that arise during treatment.
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Affiliation(s)
- Jonathan Tresley
- Department of Diagnostic Radiology, Jackson Memorial Hospital, West Wing 279, 1611 NW 12th Ave, Miami, FL, 33136, USA,
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Evaluation of the accuracy of a veterinary dynamometric wire tensioner. Vet Comp Orthop Traumatol 2015; 28:104-8. [PMID: 25633163 DOI: 10.3415/vcot-14-07-0111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 12/09/2014] [Indexed: 11/17/2022]
Abstract
OBJECTIVES The purpose of this study was to determine the accuracy of a commonly used veterinary wire tensioner. METHODS Wire tension was measured using a load cell after each of five tensioners were used to tension each of six wires to the 66, 84, and 118 mm ring settings in an adjustable custom testing fixture. Each tensioner then experienced simulated aging and testing was repeated. Percentage error was calculated for each ring size, before and after tensioner aging. Measured tension values were compared to manufacturer reported tension values for each ring size using a one-sample two-way t-test; p <0.05 was considered significant. RESULTS Compared to the manufacturer reported values, measured wire tension values were significantly lower for 66 mm and 84 mm rings and significantly higher for 118 mm rings, before and after simulated aging. Mean wire tension values did not significantly differ between individual wire tensioners. CLINICAL SIGNIFICANCE The tensioners tested achieved significantly different wire tension values than those reported by the manufacturer. This discrepancy could lead to under-tensioning and allowing excessive movement at a fracture site or over-tensioning, leading to wire breakage. We recommend tensioning wires at least to the recommended line on the device for 66 mm and 84 mm rings and at most to the recommended line for 118 mm rings. Further studies are needed to evaluate other veterinary wire tensioners and to develop a calibration method for these devices in practice.
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Hudson CC, Lewis DD, Cross AR, Horodyski M, Banks SA, Pozzi A. Axial stiffness and ring deformation of complete and incomplete single ring circular external skeletal fixator constructs. Am J Vet Res 2012; 73:2021-8. [DOI: 10.2460/ajvr.73.12.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Hudson CC, Lewis DD, Cross AR, Dunbar NJ, Horodyski M, Banks SA, Pozzi A. A Biomechanical Comparison of Three Hybrid Linear-Circular External Fixator Constructs. Vet Surg 2012; 41:954-65. [DOI: 10.1111/j.1532-950x.2012.01035.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | - Nicholas J Dunbar
- Department of Mechanical and Aerospace Engineering; College of Engineering; University of Florida; Gainesville; FL
| | | | - Scott A Banks
- Department of Mechanical and Aerospace Engineering; College of Engineering; University of Florida; Gainesville; FL
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Biomechanical comparison of strategies to adjust axial stiffness of a hybrid fixator. Vet Comp Orthop Traumatol 2012; 25:224-30. [PMID: 22451135 DOI: 10.3415/vcot-11-04-0053] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Accepted: 01/11/2012] [Indexed: 11/17/2022]
Abstract
OBJECTIVES To evaluate strategies for increasing the axial stiffness of a hybrid external bone fixator. MATERIALS AND METHODS Type Ia hybrid fixators, consisting of a uniplanar linear component connected to a circular ring, were tested in displacement controlled loading in axial compression. The basic hybrid construct was modified to explore strategies considered to increase fixator stiffness including: decreasing ring diameter, increasing ring thickness, adding pins to the ring fixation, and adding struts between the ring and vertical post components of the device. Stiffness in the initial phase of loading was compared between the groups. RESULTS The addition of a single diagonal bar between the ring and linear connecting rail did not significantly improve the stiffness of constructs. However, the addition of two half-pins to the ring, the addition of two struts between the ring and linear connecting rail, or decreasing the internal ring diameter from 115 to 85 mm progressively increased the stiffness of the frame. The most effective strategy consisted of increasing the thickness of the ring from 6 to 12 mm, thereby increasing the stiffness of the control frame by 335%. CLINICAL SIGNIFICANCE Modulating the ring thickness, adding two struts between the ring and linear connecting rail, and reducing the ring diameter appear to be the most effective, simple, and clinically versatile ways to increase axial stiffness, most likely due to their impact on reducing ring bending.
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15
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Coomer AR, Lewis DD, Wiedner E, Isaza R, Winter MD, Aloisio F, Pool R. Stabilization of juxta-physeal distal tibial and fibular fractures in a juvenile tiger using a hybrid circular-linear external fixator. Vet Surg 2011; 41:248-53. [PMID: 22092453 DOI: 10.1111/j.1532-950x.2011.00897.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To report stabilization of closed, comminuted distal metaphyseal transverse fractures of the left tibia and fibula in a tiger using a hybrid circular-linear external skeletal fixator. STUDY DESIGN Clinical report. ANIMAL Juvenile tiger (15 months, 90 kg). METHODS From imaging studies, the tiger had comminuted distal metaphyseal transverse fractures of the left tibia and fibula, with mild caudolateral displacement and moderate compression. Multiple fissures extended from the fractures through the distal metaphyses, extending toward, but not involving the distal tibial and fibular physes. A hybrid circular-linear external skeletal fixator was applied by closed reduction, to stabilize the fractures. RESULTS The fractures healed and the fixator was removed 5 weeks after stabilization. Limb length and alignment were similar to the normal contralateral limb at hospital discharge, 8 weeks after surgery. Two weeks later, the tiger had fractures of the right tibia and fibula and was euthanatized. Necropsy confirmed pathologic fractures ascribed to copper deficiency. CONCLUSION Closed application of the hybrid construct provided sufficient stability to allow this 90 kg tiger's juxta-articular fractures to heal with minimal complications and without disrupting growth from the adjacent physes.
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Affiliation(s)
- Alastair R Coomer
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610-0126, USA
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Seibert RL, Lewis DD, Coomer AR, Sereda CW, Royals SR, Leasure CS. Stabilisation of metacarpal or metatarsal fractures in three dogs, using circular external skeletal fixation. N Z Vet J 2011; 59:96-103. [DOI: 10.1080/00480169.2011.552860] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Spiegelberg B, Parratt T, Dheerendra SK, Khan WS, Jennings R, Marsh DR. Ilizarov principles of deformity correction. Ann R Coll Surg Engl 2010; 92:101-5. [PMID: 20353638 DOI: 10.1308/003588410x12518836439326] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ilizarov frames provide a versatile fixation system for the management of bony deformities, fractures and their complications. The frames give stability, soft tissue preservation, adjustability and functionality allowing bone to realise its full osteogenic potential. It is important that we have a clear and concise understanding of the Ilizarov principles of deformity correction to best make use of this fixation system. In this review article, the history of Ilizarov frame, the basic sciences behind it, the mechanical principles governing its use and the clinical use of the fixation system are discussed.
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Affiliation(s)
- B Spiegelberg
- University College London Institute of Orthopaedics and Musculoskeletal Sciences, Royal National Orthopaedic Hospital, Stanmore, Middlesex, UK
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Khurana A, Byrne C, Evans S, Tanaka H, Haraharan K. Comparison of transverse wires and half pins in Taylor Spatial Frame: a biomechanical study. J Orthop Surg Res 2010; 5:23. [PMID: 20346178 PMCID: PMC3003246 DOI: 10.1186/1749-799x-5-23] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Accepted: 03/27/2010] [Indexed: 01/12/2023] Open
Abstract
Background The aim of this study was to compare the stiffness characteristics of Taylor Spatial Frame (TSF) fixed with transverse wires and half pins. Design & Methods Experiments were carried out at the biomechanics laboratory at Cardiff University. All mechanical testing was performed with a servo hydraulic test frame (MTS 858 Mini Bionix II(R), MTS Corp., Mineapolis, USA). Custom built mounts were used to attach the bone rigidly to the one end of machine and the TSF ring to the other. Rings were fixed with 1.8 mm transverse wires or hydroxy-apatite coated 6.5 mm half pins in 45degrees, 60degrees, 75degrees and 90degrees divergence angles. Bone was loaded with axial load to 400 N and torque to 20 Nm in an indestructible manner. Load/displacement curve data were analyzed for slope and axial and angular displacements. Results For larger diameter rings (180 mm), for axial stiffness there was no statistically significant difference between the transverse wires (4 wires with 2 rings) and the half pins (2 pins with 1 ring) (p > 0.05). For 155 mm internal diameter rings, half pins provided statistically higher axial stiffness than transverse wires (p = 0.036). The half pins show significantly more torsion stiffness in both ring diameters (p < 0.05) in comparison to transverse wires. As in axial stiffness, small diameter rings show increased stiffness in torsion. There is increase in axial and torsion stiffness with the increase in the divergence angle between the wires or pins (p < 0.05). Conclusion & Clinical Relevance Half pins provide greater stiffness to TSF frames and allow for axial micro motion as well. This work provides a rationale for clinical decision making about the use of tensioned transverse wires in comparison to half pins in construction of a TSF frame
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Affiliation(s)
- Ashish Khurana
- Department of Trauma & Orthopaedics, University Hospital of Wales, Heath Park, Cardiff, UK.
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Kirkby KA, Lewis DD, Lafuente MP, Radasch RM, Fitzpatrick N, Farese JP, Wheeler JL, Hernandez JA. Management of Humeral and Femoral Fractures in Dogs and Cats With Linear- Circular Hybrid External Skeletal Fixators. J Am Anim Hosp Assoc 2008; 44:180-97. [DOI: 10.5326/0440180] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Linear-circular hybrid fixators were used to stabilize humeral and femoral fractures in 21 dogs and five cats. Twenty-two of 24 fractures with sufficient follow-up radiographic evaluation obtained union. Time to radiographic union ranged from 25 to 280 days (mean ± standard deviation [SD] 110±69 days; median 98 days). Eleven animals developed minor and two dogs developed major pin and/or wire tract inflammation. Functional outcome was rated as excellent (n=16), good (n=5), and fair (n=3) at the time of final long-term assessment (range 4.5 to 60.0 months; mean ± SD 28.4±15.4 months; median 28.5 months). Follow-up information was unavailable for two animals. Hybrid fixators were useful constructs for stabilization of humeral and femoral fractures, particularly fractures with short, juxta-articular fracture segments.
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Affiliation(s)
- Kristin A. Kirkby
- Departments of Small Animal Clinical Sciences (Kirkby, Lewis, Lafuente, Farese, Wheeler) and Large Animal Clinical Sciences (Hernandez), College of Veterinary Medicine, University of Florida, 2015 SW 16th Avenue, Gainesville, Florida 32610
- Dallas Veterinary Surgical Center (Radasch), 4444 Trinity Mills Road, Suite 203, Dallas, Texas 75287
- Orthopedic and Neurology Referrals (Fitzpatrick), Tilford, Farnham, Surrey, United Kingdom GU102DZ
- From the
| | - Daniel D. Lewis
- Departments of Small Animal Clinical Sciences (Kirkby, Lewis, Lafuente, Farese, Wheeler) and Large Animal Clinical Sciences (Hernandez), College of Veterinary Medicine, University of Florida, 2015 SW 16th Avenue, Gainesville, Florida 32610
- Dallas Veterinary Surgical Center (Radasch), 4444 Trinity Mills Road, Suite 203, Dallas, Texas 75287
- Orthopedic and Neurology Referrals (Fitzpatrick), Tilford, Farnham, Surrey, United Kingdom GU102DZ
- From the
| | - M. Pilar Lafuente
- Departments of Small Animal Clinical Sciences (Kirkby, Lewis, Lafuente, Farese, Wheeler) and Large Animal Clinical Sciences (Hernandez), College of Veterinary Medicine, University of Florida, 2015 SW 16th Avenue, Gainesville, Florida 32610
- Dallas Veterinary Surgical Center (Radasch), 4444 Trinity Mills Road, Suite 203, Dallas, Texas 75287
- Orthopedic and Neurology Referrals (Fitzpatrick), Tilford, Farnham, Surrey, United Kingdom GU102DZ
- From the
| | - Robert M. Radasch
- Departments of Small Animal Clinical Sciences (Kirkby, Lewis, Lafuente, Farese, Wheeler) and Large Animal Clinical Sciences (Hernandez), College of Veterinary Medicine, University of Florida, 2015 SW 16th Avenue, Gainesville, Florida 32610
- Dallas Veterinary Surgical Center (Radasch), 4444 Trinity Mills Road, Suite 203, Dallas, Texas 75287
- Orthopedic and Neurology Referrals (Fitzpatrick), Tilford, Farnham, Surrey, United Kingdom GU102DZ
- From the
| | - Noel Fitzpatrick
- Departments of Small Animal Clinical Sciences (Kirkby, Lewis, Lafuente, Farese, Wheeler) and Large Animal Clinical Sciences (Hernandez), College of Veterinary Medicine, University of Florida, 2015 SW 16th Avenue, Gainesville, Florida 32610
- Dallas Veterinary Surgical Center (Radasch), 4444 Trinity Mills Road, Suite 203, Dallas, Texas 75287
- Orthopedic and Neurology Referrals (Fitzpatrick), Tilford, Farnham, Surrey, United Kingdom GU102DZ
- From the
| | - James P. Farese
- Departments of Small Animal Clinical Sciences (Kirkby, Lewis, Lafuente, Farese, Wheeler) and Large Animal Clinical Sciences (Hernandez), College of Veterinary Medicine, University of Florida, 2015 SW 16th Avenue, Gainesville, Florida 32610
- Dallas Veterinary Surgical Center (Radasch), 4444 Trinity Mills Road, Suite 203, Dallas, Texas 75287
- Orthopedic and Neurology Referrals (Fitzpatrick), Tilford, Farnham, Surrey, United Kingdom GU102DZ
- From the
| | - Jason L. Wheeler
- Departments of Small Animal Clinical Sciences (Kirkby, Lewis, Lafuente, Farese, Wheeler) and Large Animal Clinical Sciences (Hernandez), College of Veterinary Medicine, University of Florida, 2015 SW 16th Avenue, Gainesville, Florida 32610
- Dallas Veterinary Surgical Center (Radasch), 4444 Trinity Mills Road, Suite 203, Dallas, Texas 75287
- Orthopedic and Neurology Referrals (Fitzpatrick), Tilford, Farnham, Surrey, United Kingdom GU102DZ
- From the
| | - Jorge A. Hernandez
- Departments of Small Animal Clinical Sciences (Kirkby, Lewis, Lafuente, Farese, Wheeler) and Large Animal Clinical Sciences (Hernandez), College of Veterinary Medicine, University of Florida, 2015 SW 16th Avenue, Gainesville, Florida 32610
- Dallas Veterinary Surgical Center (Radasch), 4444 Trinity Mills Road, Suite 203, Dallas, Texas 75287
- Orthopedic and Neurology Referrals (Fitzpatrick), Tilford, Farnham, Surrey, United Kingdom GU102DZ
- From the
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20
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Rovesti GL, Bosio A, Marcellin-Little DJ. Management of 49 antebrachial and crural fractures in dogs using circular external fixators. J Small Anim Pract 2007; 48:194-200. [PMID: 17381764 DOI: 10.1111/j.1748-5827.2006.00267.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To evaluate frame constructs, postoperative fracture reduction, postoperative care, complications, treatment duration and outcome of circular external fixation for management of 49 antebrachial and crural fractures in dogs. METHODS Medical records of dogs that underwent surgery with circular external fixation were examined for fracture location, frame configuration, postoperative fracture reduction, treatment duration, complications and outcome. RESULTS Forty-nine fractures in 48 dogs were stabilised using circular external fixation. Frame removal occurred on average 61 days after surgery (median+/-sd, 52+/-30 days). Minor complications were observed in 35 cases (71 per cent) and major complications in seven (14 per cent). Radiographic outcome at frame removal was judged as excellent in 18 cases (37 per cent), as good in 26 (53 per cent), as fair in four (8 per cent) and poor in one (2 per cent). After frame removal, one fracture was stabilised with a plate, and eight patients were lost to follow-up. Functional and cosmetic outcome at follow-up was judged as excellent in 32 cases (80 per cent), good in seven (18 per cent) and fair in one (2 per cent). CLINICAL SIGNIFICANCE Circular external fixation can effectively treat antebrachial and crural fractures in dogs, even geometrically complex fractures. Minor complications are frequent but easily managed in most instances. Healing time is comparable to that of other external fixation methods.
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Affiliation(s)
- G L Rovesti
- Ambulatorio Ventinario Associato M. E. Miller, 42025 Cavriago (RE), Italy
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21
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Rubio-Martínez LM, Koenig JB, Halling KB, Wilkins K, Schulz K. Use of a circular external skeletal fixator for stabilization of a comminuted diaphyseal metatarsal fracture in an alpaca. J Am Vet Med Assoc 2007; 230:1044-8. [PMID: 17397347 DOI: 10.2460/javma.230.7.1044] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
CASE DESCRIPTION A 3-year-old male alpaca was evaluated because of non-weight-bearing lameness (grade 5/5) in the left hind limb. CLINICAL FINDINGS Clinical and radiographic examination revealed a closed, comminuted, nonarticular, displaced diaphyseal fracture of the left third and fourth metatarsal bones. TREATMENT AND OUTCOME Initial attempts at treatment via reduction of the fracture under traction and subsequent application of a cast were unsuccessful, and more stable fracture fixation was pursued. The alpaca underwent closed reduction of the fracture, which was stabilized by the application of a 3-ring circular external skeletal fixator (CESF). Improved weight bearing on the affected limb was evident soon after surgery and gradually increased; full weight bearing was evident by the seventh day after discharge from the hospital (day 20 after application of the CESF). Lameness was hardly noticeable during walking at that time. After 3 months, complete fracture healing was evident and the CESF was removed; mild outward rotation of the distal fragment and metatarsophalangeal joint was present. A Robert Jones bandage was applied to the limb, and the alpaca was kept in a stall for another 4 weeks. Eleven months after CESF application, the owners and referring veterinarian reported that the alpaca was healthy, not lame, and serving as a stallion without apparent impediment. CLINICAL RELEVANCE Although mostly restricted to small animals, application of a CESF can be a viable alternative for management of long bone fractures in South American camelids.
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Affiliation(s)
- Luis M Rubio-Martínez
- Veterinary Teaching Hospital, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada
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22
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Abstract
External fixation has evolved from being used primarily as a last resort fixation method to becoming a main stream technique used to treat a myriad of bone and soft tissue pathologies. Techniques in limb reconstruction continue to advance largely as a result of the use of these external devices. A thorough understanding of the biomechanical principles of external fixation is useful for all orthopedic surgeons as most will have to occasionally mount a fixator throughout their career. In this review, various types of external fixators and their common clinical applications are described with a focus on unilateral and circular frames. The biomechanical principles that govern bony and fixator stability are reviewed as well as the recommended techniques for applying external fixators to maximize stability. Additionally, we have illustrated methods for managing patients while they are in the external frames to facilitate function and shorten treatment duration.
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Affiliation(s)
- Austin T Fragomen
- Hospital for Special Surgery, Weill Medical College of Cornell University, Limb Lengthening and Reconstruction Institute, 535 East 70th Street, New York, NY 10021, USA.
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23
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Roberts CS, Antoci V, Antoci V, Voor MJ. The effect of transfixion wire crossing angle on the stiffness of fine wire external fixation: a biomechanical study. Injury 2005; 36:1107-12. [PMID: 16098336 DOI: 10.1016/j.injury.2004.08.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2004] [Revised: 08/17/2004] [Accepted: 08/23/2004] [Indexed: 02/02/2023]
Abstract
To analyse the effect of transfixion wire-crossing angle on the stiffness of fine wire external fixation, a laboratory investigation using a fibreglass tibia fixed into an idealised fixator was performed with a servohydraulic test frame. Load-deformation behaviour was compared at the different wire-crossing angles (30 degrees -90 degrees ) under identical conditions of central axial compression, medial compression-bending, posterior compression-bending, posteromedial compression-bending, and torsion. Stiffness values were calculated from the load-deformation and torque-angle curves. The increase in wire-crossing angle led to an overall increase in the stiffness, except medial bending stiffness. The wire-crossing angle of 90 degrees provided significantly greater stiffness than all other angles in all load configurations (p<0.05) except medial bending. In medial bending, the wire-crossing angle of 30 degrees provided significantly greater stiffness than all the other angles (p<0.05). Increasing wire-crossing angle from 30 degrees to 90 degrees contributed to an overall increase of 75% in external fixation stiffness, which included axial, torsional, and bending stiffness, but bending stiffness was a function of the wire positioning with respect to the loading axis. Therefore, using the widest possible wire-crossing angle and placing wires as close to the loading plane as possible can increase the stiffness of external fixation.
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Affiliation(s)
- Craig S Roberts
- Department of Orthopaedic Surgery, University of Louisville School of Medicine, 210 East Gray Street, Suite 1003, Louisville, KY 40202, USA.
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24
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Rahal SC, Volpi RS, Vulcano LC. Treatment of segmental tibial defects using acute bone shortening followed by gradual lengthening with circular external fixator. ACTA ACUST UNITED AC 2005; 52:180-5. [PMID: 15882403 DOI: 10.1111/j.1439-0442.2005.00708.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The aim of this study was to clinically and radiographically evaluate acute bone shortening followed by gradual lengthening in the treatment of large segmental tibia defects induced in seven clinically normal dogs. A circular external fixator was assembled with one proximal 5/8-circle ring, one middle ring and one distal ring connected with three rods. Thirty per cent of the tibia and fibula were removed in the middle and distal parts of the diaphyses, between the middle and distal rings. Acute bone shortening with compression of proximal and distal segments was performed. A subperiosteal osteotomy was performed between the half-ring and middle ring. Bone distraction started 7 days after surgery; after lengthening, the apparatus was left in place for 14 weeks for consolidation of regenerated bone. The frame was removed at the end of this period, and the dogs observed for four more weeks. Functional results were considered excellent in two, good in three and fair in the other two dogs. Bone regeneration within the distraction gap was obtained 14 weeks after neutral fixation period. We concluded that acute bone shortening followed by gradual lengthening by Ilizarov method can be used to treat extensive tibial defects in dogs, although it presents limb temporary abnormal limb shape and unequal length as early disadvantages.
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Affiliation(s)
- S C Rahal
- Department of Veterinary Surgery and Anesthesiology, Faculty of Veterinary Medicine and Animal Science, UNESP Botucatu, Caixa, Postal 560 Rubião Júnior, s/n, CEP: 18618-000 Botucatu (SP), Brazil.
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25
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Rochat MC, Hoover JP, DiGesualdo CL. Repair of a Tibiotarsal Varus Malunion in a Bald Eagle (Haliaeetus leucocephalus) With a Type lA Hybrid External Skeletal Fixator. J Avian Med Surg 2005. [DOI: 10.1647/2004-003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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26
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Antoci V, Roberts CS, Antoci V, Voor MJ. The effect of transfixion wire number and spacing between two levels of fixation on the stiffness of proximal tibial external fixation. J Orthop Trauma 2005; 19:180-6. [PMID: 15758671 DOI: 10.1097/00005131-200503000-00005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVES Anatomic constraints about the proximal tibia limit the ability to insert wires at the biomechanically optimum angle of 90 degrees, thus diminishing the potential stability of external fixators used for proximal tibial fractures. To overcome this problem, surgeons use more than 2 wires at a single level of fixation or a second level of fixation. This study evaluated the effect of transfixion wire number and placement of a second level of fixation on the stiffness of proximal tibial external fixation. METHODS A fiberglass tibia fixed into an idealized ring external frame was tested. Load-deformation behavior was compared among the different wire numbers (1 level with 2, 3, 4, and 5 wires) and placement of a second level of fixation (2 wires first level and 1 wire second level, and 2 wires first level and 2 wires second level) at 2, 3, 4, 5, 6, 7, 8, 9, and 10 cm distance from the first level of fixation. Identical loading conditions of central axial compression, medial compression-bending, posterior compression-bending, posteromedial compression-bending, and torsion were used. Stiffness values were calculated from the load-displacement and the torque-angle curves. RESULTS An increase in wire number at 1 level led to an overall increase in stiffness, whereas the addition of a second level of fixation and increased spread between these 2 levels increased bending stiffness. CONCLUSIONS The addition of a second level of external fixation of the proximal tibia fragment with maximum possible distance between the 2 levels increases bending stiffness, whereas increasing the number of transfixion wires increases overall stiffness. Axial and torsional stiffness is proportional to the total number of wires regardless of the number of levels of fixation.
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Affiliation(s)
- Valentin Antoci
- Department of Orthopaedic Surgery, University of Louisville School of Medicine, Louisville, KY 40202, USA
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27
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Abstract
Surgeons who use external fixators for foot and ankle conditions need to understand the biomechanical principles to ensure good outcomes. Fixators can be used for fracture fixation, correction of contractures, distraction osteogenesis, and distraction arthroplasty. A two-ring fixator with wire fixation remains the gold standard with which all other frames are compared. Small changes in mechanical characteristics can have major implications on new bone or cartilage formation.
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Joyner PH, Rochat MC, Hoover JP. Use of a hybrid external skeletal fixator for repair of a periarticular tibial fracture in a Patagonian cavy. J Am Vet Med Assoc 2004; 224:1298-301, 1280. [PMID: 15112778 DOI: 10.2460/javma.2004.224.1298] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
An 8-week-old female Patagonian cavy was examined because of acute right hind limb lameness; radiography revealed a moderately displaced, comminuted fracture of the proximal third of the tibia. The fracture was stabilized with a hybrid external skeletal fixator. Two Kirschner wires were placed in the main proximal fragment, parallel to the tibial plateau and at right angles to each other. These wires were connected to a partial circular external fixator ring. Three half pins were placed in the distal fragment, and a straight connecting rod positioned on the medial side of the limb was connected to these pins and the fixator ring. A second connecting rod was positioned on the craniomedial side of the limb and was connected to the fixator ring and a fourth half pin in the distal fragment. The fracture healed without complications, and the fixator was removed 3 weeks after surgery. Hybrid external skeletal fixators combine the benefits of circular and linear external skeletal fixation methods, enabling rigid fixation of periarticular long bone fractures without adversely affecting mobility of the adjacent joint.
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Affiliation(s)
- Priscilla H Joyner
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK 74078, USA
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Cross AR, Lewis DD, Rigaud S, Rapoff AJ. Effect of various distal ring-block configurations on the biomechanical properties of circular external skeletal fixators for use in dogs and cats. Am J Vet Res 2004; 65:393-8. [PMID: 15077678 DOI: 10.2460/ajvr.2004.65.393] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate mediolateral, axial, torsional, and craniocaudal bending behavior of 6 distal ring-block configurations commonly used to stabilize short juxta-articular bone segments in small animals. SAMPLE POPULATION 8 circular external skeletal fixator constructs of each of 6 distal ring-block configurations. The distal ring-block configurations were composed of combinations of complete rings, incomplete rings, and drop wires. PROCEDURE Constructs were nondestructively loaded in axial compression, craniocaudal bending, mediolateral bending, and torsional loading by use of a materials testing machine. Gap stiffness was determined by use of the resultant load displacement curve. RESULTS Circular external skeletal fixator configurations and constructs significantly affected gap stiffness in all testing modes. Within each loading mode, gap stiffness was significantly different among most configurations. In general, complete ring configurations were significantly stiffer than similar incomplete ring configurations, and addition of a drop wire to a configuration significantly increased stiffness of that configuration. CONCLUSIONS AND CLINICAL RELEVANCE When regional anatomic structures permit, the use of complete ring configurations is preferred over incomplete ring configurations. When incomplete ring configurations are used, the addition of a drop wire is recommended.
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Affiliation(s)
- Alan R Cross
- Department of Small Animal Clinical Sciences and the Center for Veterinary Sports Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL 32610, USA
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30
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Roberts CS, Antoci V, Antoci V, Voor MJ. The accuracy of fine wire tensioners: a comparison of five tensioners used in hybrid and ring external fixation. J Orthop Trauma 2004; 18:158-62. [PMID: 15091270 DOI: 10.1097/00005131-200403000-00006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVES To compare the accuracy of 5 commonly available fine wire tensioners used in hybrid and ring external fixation. DESIGN A laboratory investigation. SETTING The testing of 5 commonly available tensioners was performed with a servohydraulic test frame (MTS Bionix 858, Minneapolis, MN). MAIN OUTCOME MEASUREMENT The real wire tension data of each tensioner provided by the MTS were compared with corresponding nominal values. The percent error for each tensioner was calculated. Clinical ease of usage of the wire tensioners was also evaluated. RESULTS The EBI tensioner was the most accurate (-0.17% to 0.09% error). The Smith and Nephew tensioner had a -13.97% to -8.61% error, the How medica tensioner a -12.48% to -10.86% error, and the Synthes tensioner a -0.2% to 24.28% error. The DePuyACE tensioner was the least accurate, with errors ranging from -36.76% to -30.92%. The Howmedica tensioner was the easiest to use, followed by the Smith and Nephew tensioner, the DePuyACE tensioner, the Synthes tensioner, and the EBI tensioner. CONCLUSIONS Most commonly available tensioners tend to undertension. Future efforts should focus on the development of wire tensioners that combine accuracy and ease of usage.
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Affiliation(s)
- Craig S Roberts
- Department of Orthopaedic Surgery, University of Louisville School of Medicine, Louisville, KY 40202, USA.
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31
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Halling KB, Lewis DD, Cross AR, Sammy RJ, Rapoff AJ. Biomechanical comparison of a circular external skeletal fixator construct to pin and tension band wire fixation for the stabilization of olecranon osteotomies in dogs: a cadaveric study. Vet Surg 2003; 32:324-35. [PMID: 12865994 DOI: 10.1053/jvet.2003.50045] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To compare anatomic reduction and the biomechanical properties of a circular external skeletal fixator (CESF) construct to pin and tension band wire (PTBW) fixation for the stabilization of olecranon osteotomies in dogs. STUDY DESIGN Cadaveric study. ANIMALS Forelimbs from 12 skeletally mature mixed-breed dogs, weighing 23 to 28 kg. METHODS An olecranon osteotomy was stabilized with either a CESF construct or PTBW fixation. A single distractive load to failure was applied to each specimen through the triceps tendon. Osteotomy reduction and biomechanical properties were compared between fixation groups. RESULTS Reduction was not significantly different (gap: P =.171; malalignment: P =.558) between fixation groups. Osteotomies stabilized with the CESF had greater stiffness (P <.0001) and maximum load sustained (P <.0001) compared to PTBW fixation. There was no significant difference for yield load (P =.318) or for load at 1 mm of axial displacement (P =.997) between fixation groups. Failure of fixation occurred by bending of the intramedullary Steinmann pin and the fixation wires in the CESF specimens and by untwisting of the tension band wire knot with pullout and bending of the Kirschner wires in the PTBW specimens. CONCLUSIONS Specimens stabilized with the CESF construct had similar reduction and yield load, greater stiffness and maximum load sustained, and less elastic deformation than specimens stabilized with PTBW fixation. CLINICAL RELEVANCE The CESF construct may provide a biomechanically favorable alternative to PTBW fixation for stabilization of olecranon osteotomies in dogs, and its application warrants clinical investigation.
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Affiliation(s)
- Krista B Halling
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA
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Störk CK, Canivet P, Baidak AA, Balligand MH. Evaluation of a nontoxic rigid polymer as connecting bar in external skeletal fixators. Vet Surg 2003; 32:262-8. [PMID: 12784203 DOI: 10.1053/jvet.2003.50029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To investigate the mechanical characteristics of a nontoxic, low-cost, rigid polymer (RP) and to compare the structural and mechanical properties of a full-frame external skeletal fixator (ESF) with either RP connecting bars, polymethylmethacrylate (PMMA) connecting bars, or stainless-steel (SS) clamps and connecting bars. STUDY DESIGN In vitro mechanical evaluation. METHODS Mechanical properties were assessed using an in vitro bone fracture model with a bilateral uniplanar ESF (type II). Identical ESF were built with connecting bars using RP (n = 8), PMMA (n = 8), and SS connecting bars and clamps (System Meynard; n = 3). Nondestructive mechanical tests were performed in uniaxial compression (AC) and craniocaudal (CC) 4-point bending, as well as fatigue AC. Composite stiffness for each specimen and for each loading mode was calculated from 6 replicate measures using the slope of the load displacement curve at small displacements. RESULTS RP, PMMA, and SS ESF constructs yielded mean +/- SD composite stiffness values of 227 +/- 15, 381 +/- 30, and 394 +/- 9 N/mm in AC and of 35 +/- 2, 24 +/- 2, and 15 +/- 0 N/mm in CC, respectively. CONCLUSIONS Structural and mechanical properties of RP are satisfactorily rigid and fatigue resistant for its use as a connecting bar in ESF. CLINICAL RELEVANCE RP connecting bars in an ESF are a reliable, versatile, nontoxic and inexpensive option for the veterinary surgeon.
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Affiliation(s)
- Christoph K Störk
- Department of Clinical Sciences, Faculty of Veterinary Medicine and the Department of Macromolecular Chemistry and Multi-Materials, Faculty of Applied Sciences, University of Liège, Liège, Belgium.
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Wosar MA, Marcellin-Little DJ, Roe SC. Influence of bolt tightening torque, wire size, and component reuse on wire fixation in circular external fixation. Vet Surg 2002; 31:571-6. [PMID: 12415526 DOI: 10.1053/jvet.2002.34672] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVES To evaluate the effects of bolt torque, wire size, and component reuse on the ability to maintain wire tension in 3 external skeletal fixation systems. STUDY DESIGN Biomechanical study. METHODS Yield strength in tension of 1.0-, 1.2-, 1.5-, and 1.6-mm-diameter wires, and yield strength in torque of Hofmann Small Bone Fixation (SBF) cannulated and slotted bolts and IMEX regular and miniature bolts were determined on a testing machine. The minimum bolt tightening torque needed to prevent wire slippage at clinically recommended wire tensions was determined. Components were tested 10 times, and loads at slippage were recorded. RESULTS The IMEX system required a mean of 8 Nm of bolt tightening torque to maintain 900 N (1.6-mm wires). The SBF system required a mean of 3 Nm bolt torque to maintain 300 N (1.0-mm wires) and 5 Nm to maintain 600 N (1.2-mm wires). The SBF cannulated bolt required 9 Nm of torque to maintain 900 N (1.5-mm wires). The SBF slotted bolts could only maintain 800 N before yield. The IMEX miniature system required a mean bolt torque of 1.1 Nm to maintain 300 N. The cannulated and slotted bolts from both manufacturers failed to maintain 70% of initial wire tension after 7 and 4 uses, respectively. CONCLUSIONS The IMEX systems and the SBF system using 1.0- and 1.2-mm wires could maintain clinically recommended wire tension safely. Only the IMEX system could maintain clinically recommended wire tension safely using 1.5- or 1.6-mm wires. CLINICAL RELEVANCE The SBF system using 1.0- and 1.2-mm wires and the IMEX system using all wire sizes can maintain clinically relevant wire tension. The SBF system using 1.5-mm wires could not. Cannulated and slotted bolts should not be used more than 6 and 3 times, respectively. Nuts should not be reused.
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Affiliation(s)
- Marc A Wosar
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh 27606, USA
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