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Sisk MR, Yang LC, Paul KD, Elphingstone JW, Brabston EW, Ponce BA, Martin EC, Corriveau KM. Biomechanical Principles of Intramedullary Nails in Veterinary and Human Medicine. Vet Comp Orthop Traumatol 2024. [PMID: 38981690 DOI: 10.1055/s-0044-1788316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
Intramedullary nails are specialized metal rods inserted into the medullary cavity of a fractured bone and secured to reduce load on the fracture site, provide stability, and permit healing. The purpose of this review is to highlight the biomechanics of orthopaedic intramedullary nailing, as well as discuss the biomechanical considerations that have shaped implant design and fixation technique in veterinary and human medicine. Relevant studies were included from the PubMed database and Google Scholar for discussion on the basic science and nail design of intramedullary nails. Implant design and implementation continues to progress, with new innovative designs currently under investigation. A lack of consensus remains on the superior implant material. Recent studies, particularly in human populations, have supported the use of reaming based on reoperation rates, nonunion rates, and dynamization. Design modifications, such as the expandable intramedullary nails and angle-stable interlocking designs, have been investigated as methods of improving cortical contact and resisting torsional stress. Intramedullary nailing is a valuable stabilization technique for long bone fractures across a variety of species. The technology continues to undergo design improvements in both veterinary and human medicine.
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Affiliation(s)
- Morgan R Sisk
- Department of Orthopaedic Surgery, University of Alabama in Birmingham Heersink School of Medicine, Birmingham, Alabama, United States
| | - Lydia C Yang
- Department of Orthopaedic Surgery, University of Alabama in Birmingham Heersink School of Medicine, Birmingham, Alabama, United States
| | - Kyle D Paul
- Department of Orthopaedic Surgery, University of Alabama in Birmingham Heersink School of Medicine, Birmingham, Alabama, United States
| | - Joseph W Elphingstone
- Department of Orthopaedic Surgery, University of Alabama in Birmingham, Birmingham, Alabama, United States
| | - Eugene W Brabston
- Department of Orthopaedic Surgery, University of Alabama in Birmingham, Birmingham, Alabama, United States
| | - Brent A Ponce
- Hughston Foundation, Hughston Clinic, Columbus, Georgia, United States
| | | | - Kayla M Corriveau
- Department of Clinical Sciences, Auburn University College of Veterinary Medicine, Auburn, Alabama, United States
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Mund GM, Bitterli T, Häußler TC, Gerwing M, Feichtenschlager C. Management of Feline Femoral, Tibial and Humeral Fractures Using a 3.5 mm Titanium Interlocking Nail. Vet Comp Orthop Traumatol 2023; 36:53-62. [PMID: 36150695 DOI: 10.1055/s-0042-1756515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
OBJECTIVE Our objectives were to report complications associated with stabilization of long-bone fractures in cats using a 3.5-mm titanium interlocking nail and to examine the influences of signalment, fracture type and fixation evaluations on the occurrence of complications. STUDY DESIGN Retrospective clinical study. MATERIAL AND METHODS Medical and radiographic records of cats with long-bone fractures treated with an interlocking nail were reviewed. Data included age, sex, weight, cause of the fracture, fractured bone(s) and fracture type. Complications were classified as minor and major complications. Fisher's exact tests and logistic regression analysis were used to test whether certain variables of signalment and interlocking nail configuration had an effect on the occurrence of complications. RESULTS Sixty-seven fractures of 67 cats were examined in this study. Forty-eight femora, sixteen tibiae and three humeri were included. Complications occurred in 11/67 fractures. Major complications occurred in 8/67 fractures and included screw breakage (n = 3), nail breakage (n = 2), nail bending (n = 1), screw loosening (n = 1), non-union (n = 1). Statistical analysis showed a significant difference between fracture types and the occurrence of major complications (p = 0.02). CONCLUSION In conclusion, use of this commercially available standard 3.5-mm titanium interlocking nail for stabilization of comminuted and oblique humeral, femoral and tibial fractures in cats is feasible.
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Affiliation(s)
- Georg Michael Mund
- Department of Small Animal Surgery, Justus Liebig Universitat Giessen, Giessen, Hessen, Germany
| | - Thomas Bitterli
- Department of Small Animal Surgery, Justus Liebig Universitat Giessen, Giessen, Hessen, Germany
| | | | - Martin Gerwing
- Department of Small Animal Surgery, Justus Liebig Universitat Giessen, Giessen, Hessen, Germany
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Deprey J, Blondel M, Saban C, Massenzio M, Gauthier O, Moissonnier P, Viguier E, Cachon T. Mechanical evaluation of a novel angle-stable interlocking nail in a gap fracture model. Vet Surg 2022; 51:1247-1256. [PMID: 35675144 DOI: 10.1111/vsu.13837] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 03/05/2022] [Accepted: 05/14/2022] [Indexed: 12/01/2022]
Abstract
OBJECTIVE To describe the mechanical characteristics of a novel angle-stable interlocking nail (NAS-ILN) and compare them to those of a locking compression plate (LCP) by using a gap-fracture model. STUDY DESIGN Experimental study. SAMPLE POPULATION Synthetic bone models. METHODS Synthetic bone models simulating a 50 mm diaphyseal comminuted canine tibial fracture were treated with either a novel angle-stable interlocking nail (NAS-ILN) or a locking compression plate (LCP). Maximal axial deformation and load to failure in compression and 4-point bending, as well as maximal angular deformation, slack, and torque to failure in torsion, were statistically compared (P < .05). RESULTS In compression, the maximal axial deformation was lower for NAS-ILN (0.11 mm ± 0.03) than for LCP (1.10 mm ± 0.22) (P < .0001). The ultimate load to failure was higher for NAS-ILN (803.58 N ± 29.52) than for LCP (328.40 N ± 11.01) (P < .0001). In torsion, the maximal angular deformation did not differ between NAS-ILN (22.79° ± 1.48) and LCP (24.36° ± 1.45) (P = .09). The ultimate torque to failure was higher for NAS-ILN (22.45 Nm ± 0.24) than for LCP (19.10 Nm ± 1.36) (P = .001). No slack was observed with NAS-ILN. In 4-point bending, the maximal axial deformation was lower for NAS-ILN (3.19 mm ± 0.49) than for LCP (4.17 mm ± 0.34) (P = .003). The ultimate bending moment was higher for NAS-ILN (25.73 Nm, IQR [23.54-26.86] Nm) than for LCP (16.29 Nm, IQR [15.66-16.47] Nm) (P = .002). CONCLUSION The NAS-ILN showed greater stiffness in compression and 4-point bending, and a greater resistance to failure in compression, torsion, and 4-point bending, than LCP. CLINICAL IMPACT Based on these results, NAS-ILNs could be considered as alternative implants for the stabilization of comminuted fractures.
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Affiliation(s)
- Julie Deprey
- Department of Small Animal Surgery, VetAgro Sup, Campus Vétérinaire de Lyon, Marcy l'Etoile, France.,Research Unit ICE, UPSP 2016-A104, Université de Lyon, VetAgro Sup, Marcy l'Etoile, France
| | - Margaux Blondel
- Department of Small Animal Surgery, VetAgro Sup, Campus Vétérinaire de Lyon, Marcy l'Etoile, France.,Research Unit ICE, UPSP 2016-A104, Université de Lyon, VetAgro Sup, Marcy l'Etoile, France
| | - Charles Saban
- Department of Small Animal Surgery, VetAgro Sup, Campus Vétérinaire de Lyon, Marcy l'Etoile, France.,Research Unit ICE, UPSP 2016-A104, Université de Lyon, VetAgro Sup, Marcy l'Etoile, France
| | - Michel Massenzio
- Univ Lyon, Université Claude Bernard Lyon 1, Univ Gustave Eiffel, IFSTTAR, Lyon, France
| | - Olivier Gauthier
- Department of Small Animal Surgery and Anesthesia, ONIRIS Nantes-Atlantic College of Veterinary Medicine, Food Science and Engineering, Nantes, France
| | - Pierre Moissonnier
- Department of Small Animal Surgery, VetAgro Sup, Campus Vétérinaire de Lyon, Marcy l'Etoile, France.,Research Unit ICE, UPSP 2016-A104, Université de Lyon, VetAgro Sup, Marcy l'Etoile, France
| | - Eric Viguier
- Department of Small Animal Surgery, VetAgro Sup, Campus Vétérinaire de Lyon, Marcy l'Etoile, France.,Research Unit ICE, UPSP 2016-A104, Université de Lyon, VetAgro Sup, Marcy l'Etoile, France
| | - Thibaut Cachon
- Department of Small Animal Surgery, VetAgro Sup, Campus Vétérinaire de Lyon, Marcy l'Etoile, France.,Research Unit ICE, UPSP 2016-A104, Université de Lyon, VetAgro Sup, Marcy l'Etoile, France
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Biomechanical comparison of a new expandable intramedullary nail and conventional intramedullary nails for femoral osteosynthesis in dogs. PLoS One 2020; 15:e0231823. [PMID: 32369494 PMCID: PMC7200017 DOI: 10.1371/journal.pone.0231823] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 04/01/2020] [Indexed: 11/19/2022] Open
Abstract
Intramedullary nailing of diaphyseal femoral fractures is a commonly used treatment method in dogs because of its biological and biomechanical advantages compared to bone plating. To achieve adequate resistance of the intramedullary nail against torsional and axial compressive forces, additional application of transcortical screws is needed. As these interlocking screws represent a frequent cause of post-operative complications, a new expandable intramedullary nail (EXPN) was developed, which was designed to provide adequate fracture stabilisation without the need for transcortical fixation. The evaluation of the biomechanical properties of the new EXPN with regard to torsional, compressive and bending stability as well as direct comparison to the biomechanical properties of conventional Steinmann (STMN)- and interlocking (ILN) nails was carried out with different biomechanical test arrangements. No significant statistical differences regarding the torsional and bending resistance between the EXPN and ILN group were seen, which indicates that rotatory as well as bending stability of the innovative EXPN is similar to the conventional ILN. Nevertheless, the percentage deviation between the attempted and successfully reached physiological compressive forces was significantly higher (p = 0.045) in the EXPN group compared to the ILN group, which indicates that the compressive stability of the innovative EXPN might be weaker compared to the ILN. In summary, the new EXPN represents an interesting alternative to conventional intramedullary nails. However, in direct comparison to conventional interlocking nails, the EXPN has shown weaknesses in the neutralization of axial compressive forces, which indicates that at least biomechanically the interlocking nail seems advantageous. Further in-vitro and in-vivo investigations are required before clinical use can be recommended.
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Déjardin LM, Perry KL, von Pfeil DJF, Guiot LP. Interlocking Nails and Minimally Invasive Osteosynthesis. Vet Clin North Am Small Anim Pract 2019; 50:67-100. [PMID: 31668598 DOI: 10.1016/j.cvsm.2019.09.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reviews of clinical outcomes led to the foundation of a new approach in fracture management known as biological osteosynthesis. As intramedullary rods featuring cannulations and locking devices at both extremities, interlocking nails are well suited for bridging osteosynthesis. Unique biological and mechanical benefits make them ideal for minimally invasive nail osteosynthesis and an attractive, effective alternative to plating, particularly in revisions of failed plate osteosynthesis. Thanks to a new angle-stable locking design, interlocking nailing indications have been expanded to osteosynthesis of epi-metaphyseal fractures, including those with articular involvement and angular deformities such as distal femoral varus and associated patellar luxations.
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Affiliation(s)
- Loïc M Déjardin
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, East Lansing, MI 48824, USA.
| | - Karen L Perry
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, East Lansing, MI 48824, USA
| | - Dirsko J F von Pfeil
- Sirius Veterinary Orthopedic Center, 3125 South 61st Avenue, Omaha, NE 68106, USA
| | - Laurent P Guiot
- ACCESS Bone & Joint Center, ACCESS Specialty Animal Hospital, 9599 Jefferson Boulevard, Culver City, CA 90232, USA
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An in vitro biomechanical investigation of an interlocking nail system developed for buffalo tibia. Vet Comp Orthop Traumatol 2017; 27:36-44. [DOI: 10.3415/vcot-12-12-0149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 09/09/2013] [Indexed: 11/17/2022]
Abstract
SummaryObjectives: The objectives of the study were to determine the mechanical properties of a customized buffalo interlocking nail (BIN), intact buffalo tibia, and ostectomized tibia stabilized with BIN in different configurations, as well as to assess the convenience of interlocking nailing in buffalo tibia.Methods: The BIN (316L stainless steel, 12 mm diameter, 250 mm long, nine-hole solid nails with 10° proximal bend) alone was loaded in compression and three-point bending (n = 4 each); intact tibiae and ostectomized tibiae (of buffaloes aged 5–8 years, weighing 300–350 kg) stabilized with BIN using 4.9 mm standard or modified locking bolts (4 or 8) in different configurations were subjected to axial compression, cranio-caudal three-point bending and torsion (n = 4 each) using a universal testing machine. Mechanical parameters were determined from load-displacement curves and compared using Kruskal-Wallis test (p <0.05).Results: Intact tibiae were significantly stronger than BIN and bone-BIN constructs in all testing modes. The strength of fixation constructs with eight locking bolts was significantly more than with four bolts. Overall strength of fixation with modified locking bolts was better than standard bolts. Based on technical ease and biomechanical properties, cranio-caudal insertion of bolts into the bone was found better than medio-lateral insertion.Clinical significance: The eight bolt BINbone constructs could be useful to treat tibial fractures in large ruminants, especially buffaloes.
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Segmented interlocking nail: An in vivo evaluation of a novel humeral osteotomy fixation device in a caprine model. Vet Comp Orthop Traumatol 2017; 25:28-35. [DOI: 10.3415/vcot-11-04-0060] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2011] [Accepted: 07/27/2011] [Indexed: 11/17/2022]
Abstract
SummaryObjectives: To describe a novel humeral fixation device, the insertion technique, healing of humeral osteotomies, and clinical outcomes in a caprine model over a six month period.Methods: Fourteen mature female Boer/Nubian cross goats with a mean body weight of 50.7 kg were implanted with a proprietary segmented interlocking nail (SILN) in both humeri. Each goat had one humerus randomly selected for mid-diaphyseal osteotomy.Results: Immediately after surgery all but one goat was able to stand, although none of the goats were weight bearing on the osteotomy limb. During the six month study, clinical lameness was always associated with the osteotomy limb. One month after surgery, lameness for twelve of the goats was grade 2/5 or better. At three months, 11 of the 14 did not exhibit any signs of lameness. On radio-graphic images, notable malalignment of the osteotomy was observed, although all osteotomies went to bone union.Clinical significance: The results of this study suggest that despite misalignment, the SILN maintained adequate osteotomy fixation to achieve bone union in the research model studied, with reduced morbidity and early return to function with bilateral implantation. The SILN used in this study allowed intramedullary fixation of humeral diaphyseal osteotomies with a limited and safe surgical approach.
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Matres-Lorenzo L, Diop A, Maurel N, Boucton MC, Bernard F, Bernardé A. Biomechanical Comparison of Locking Compression Plate and Limited Contact Dynamic Compression Plate Combined with an Intramedullary Rod in a Canine Femoral Fracture-Gap Model. Vet Surg 2016; 45:319-26. [PMID: 26909507 DOI: 10.1111/vsu.12451] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To compare the biomechanical properties of locking compression plate (LCP) and a limited contact dynamic compression plate combined with an intramedullary rod (LC-DCP-R) in a cadaveric, canine, femoral fracture-gap model. STUDY DESIGN In vitro biomechanical study; nonrandomized, complete block (dog). SAMPLE POPULATION Paired cadaveric canine femora (n = 10 dogs). METHODS Paired femurs with a mid-diaphyseal 20 mm gap were stabilized with either LCP or LC-DCP-R. Nondestructive testing up to 60% of body weight (BW) was followed by a continuous destructive test. Comparative structural properties, 3-dimensional (3D) interfragmentary motion, and plate linear strain were evaluated. Paired comparisons were made between LCP and LC-DCP-R. RESULTS Stiffness after nondestructive testing was significantly lower for LCP with a mean (95% confidence interval [CI]) of 61 N/mm (46-76) versus 89 N/mm (67-110) for LC-DCP-R (P = .0072). Ultimate load to failure was significantly lower for LCP with a median (interquartile range [IQR]) of 270 N (247-286) versus 371.5 (353-385) for LC-DCP-R (P = .002). Axial motion at 60% BW was significantly higher for LCP with a median (IQR) of 1.01 mm (0.71-1.26) versus 0.36 mm (0.20-0.49) for LC-DCP-R (P = .002). Shear motion was significantly higher for LCP with a median (IQR) of 1.18 (0.78-1.58) versus 0.72 mm (0.45-1.00) for LC-DCP-R (P = .018). Strain was significantly higher for mid-LCP surface with a mean (95%CI) at 60% BW of 979 μdef (579-1378) versus 583 μdef (365-801) at mid-LC-DCP-R surface (P = .0153). The elastic limit strain of the plates was not different and was reached at a mean (95%CI) load of 241 N (190-292) for LCP versus 290 N (245-336) for LC-DCP-R (P = .12). CONCLUSION The LC-DCP-R showed higher stiffness and resistance to failure, lower interfragmentary motion, and lower plate strain and stress compared to LCP.
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Affiliation(s)
| | - Amadou Diop
- Equipe Biomécanique et Remodelage Osseux (EPBRO), École Nationale Supérieure d'Arts et Métiers, Paris, France
| | - Nathalie Maurel
- Equipe Biomécanique et Remodelage Osseux (EPBRO), École Nationale Supérieure d'Arts et Métiers, Paris, France
| | - Marie-Charlotte Boucton
- Equipe Biomécanique et Remodelage Osseux (EPBRO), École Nationale Supérieure d'Arts et Métiers, Paris, France
| | - Fabrice Bernard
- Centre Hospitalier Vétérinaire Saint-Martin, Saint Martin Bellevue, France
| | - Antoine Bernardé
- Centre Hospitalier Vétérinaire Saint-Martin, Saint Martin Bellevue, France
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Pozzi A, Peck JN, Chao P, Choate CJ, Barousse D, Conrad B. Mechanical Evaluation of Adjunctive Fixation for Prevention of Periprosthetic Femur Fracture With the Zurich Cementless Total Hip Prosthesis. Vet Surg 2013; 42:529-34. [DOI: 10.1111/j.1532-950x.2013.12018.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 02/01/2013] [Indexed: 11/27/2022]
Affiliation(s)
- Antonio Pozzi
- Department of Small Animal Clinical Sciences, Comparative Orthopaedics and Biomechanics Laboratory; University of Florida, College of Veterinary Medicine; Gainesville; Florida
| | | | - Peini Chao
- Department of Small Animal Clinical Sciences, Comparative Orthopaedics and Biomechanics Laboratory; University of Florida, College of Veterinary Medicine; Gainesville; Florida
| | - Christina J. Choate
- Department of Small Animal Clinical Sciences, Comparative Orthopaedics and Biomechanics Laboratory; University of Florida, College of Veterinary Medicine; Gainesville; Florida
| | - Dan Barousse
- Department of Small Animal Clinical Sciences, Comparative Orthopaedics and Biomechanics Laboratory; University of Florida, College of Veterinary Medicine; Gainesville; Florida
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Treatment of tibial shaft fractures in sheep using interlocking nails, Schanz screws and type I external fixators. Pol J Vet Sci 2013; 15:651-9. [PMID: 23390754 DOI: 10.2478/v10181-012-0102-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This paper presents the results of a study of the treatment of transverse tibial shaft fractures in six sheep with the use of interlocking nails and type I extemal fixators. During surgery, tibial osteotomy was performed to induce an experimental fracture which was stabilized using a type I extemal fixator. Osteosynthesis was monitored for nine weeks by performing clinical tests, observing the degree of lameness and subjecting the patients to weekly radiological examinations. After nine weeks, the animals were euthanized, and samples of bone callus were sampled for histopathological analyses. Weight bearing on the fractured limb began on day 2 to 4 after treatment. Limb function was fully restored around five weeks after surgery. Radiograms taken during the observation period revealed gradual hyperplasia and progressing mineralization of bone callus at different stages of healing. The histopathological picture of the bone callus was characteristic of the phase of bone turnover and remodeling.
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11
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Interlocking Nails and Minimally Invasive Osteosynthesis. Vet Clin North Am Small Anim Pract 2012; 42:935-62, vi. [DOI: 10.1016/j.cvsm.2012.07.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Burns CG, Litsky AS, Allen MJ, Johnson KA. Influence of Locking Bolt Location on the Mechanical Properties of an Interlocking Nail in the Canine Femur. Vet Surg 2011; 40:522-30. [DOI: 10.1111/j.1532-950x.2011.00838.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Gatineau M, Planté J. Ulnar Interlocking Intramedullary Nail Stabilization of a Proximal Radio-Ulnar Fracture in a Dog. Vet Surg 2010; 39:1025-9. [DOI: 10.1111/j.1532-950x.2010.00731.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Lewis D, Lutton C, Wilson LJ, Crawford RW, Goss B. Low cost polymer intramedullary nails for fracture fixation: a biomechanical study in a porcine femur model. Arch Orthop Trauma Surg 2009; 129:817-22. [PMID: 19172285 DOI: 10.1007/s00402-009-0819-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Whilst intramedullary nailing is a commonly accepted technique for lower limb fracture fixation, the cost of nails can be prohibitive in hospitals in developing nations. In these institutions bone cement has found many off label applications, that whilst are effective do not meet manufacturers guidelines. The aim of this study was to examine the biomechanics of one such application, fracture fixation using a bone cement intramedullary nail. MATERIALS AND METHODS Five porcine femurs underwent a mid-shaft osteotomy and were fixed using a nail made from antibiotic simplex bone cement. The torsional and flexural stiffness and shear modulus of these constructs were compared to five intact porcine femurs. RESULTS The bone cement intramedullary nail was able to achieve relative stability in both torsion, with a mean shear modulus of 0.17 GPa and in flexion with a mean flexural stiffness of 358 N/mm. This corresponds to 47 and 22% of the respective measurements in the intact femurs. The mean ultimate flexural strength of fracture/nail constructs was 936 +/- 350 N, which is 20% of the ultimate flexural strength of an intact porcine femur (4,820 +/- 698 N). CONCLUSION Intramedullary nails made from bone cement were able to provide sufficient promise in this situation to warrant further investigation for their applicability as a low cost alternative for use in developing countries.
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Affiliation(s)
- D Lewis
- AOSpine Reference Centre, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
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15
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Lansdowne JL, Sinnott MT, Déjardin LM, Ting D, Haut RC. In Vitro Mechanical Comparison of Screwed, Bolted, and Novel Interlocking Nail Systems to Buttress Plate Fixation in Torsion and Mediolateral Bending. Vet Surg 2007; 36:368-77. [PMID: 17547600 DOI: 10.1111/j.1532-950x.2007.00277.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To compare standard interlocking nails (ILN) with a newly designed ILN featuring an angle-stable locking mechanism (ILNn). STUDY DESIGN Six experimental groups. SAMPLE POPULATION Bone models (n=48) treated with 6 and 8 mm nails locked with screws or bolts (ILN6s, ILN8s, ILN6b, ILN8b, respectively), ILNn, and a 3.5 mm broad-DCP (br-DCP); n=4/testing mode. METHODS Specimens were tested in torsion or 4-point bending. Construct compliance, deformation, and slack were statistically compared (P<.05). RESULTS Regardless of testing mode, construct compliance was greater with smaller ILN. Screwed constructs were more compliant than bolted ones, with a significant difference between ILN6s and ILN6b in torsion. Plated constructs were significantly more compliant than the ILNn. Angular deformation was consistently greater with smaller ILN. Screwed ILN constructs sustained approximately 2 x the torsional deformation of the bolted ones (approximately 36 degrees [ILN6s] versus approximately 18 degrees [ILN6b]). Comparatively, ILNn constructs had significantly less torsional (approximately 8 degrees) and bending (approximately 4 degrees) deformation than other constructs. Whereas standard ILN constructs had slack in both modes, ILNn and br-DCP construct deformations consistently occurred without slack. CONCLUSIONS Use of bolts rather than screws improved ILN mechanical behavior, but neither locking mechanism completely counteracted torsion and bending forces. Conversely, the ILNn angle-stable locking system eliminated torsional and bending slack, resulting in comparable mechanical performances between ILNn and plated constructs. CLINICAL RELEVANCE The angle-stable locking mechanism of the new ILN eliminates all slack in the system; thus, interfragmentary motion will likely be reduced compared with standard ILN, which may improve the local environment for fracture healing.
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Affiliation(s)
- Jennifer L Lansdowne
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
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16
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Reems MR, Pluhar GE, Wheeler DL. Ex vivo comparison of one versus two distal screws in 8 mm model 11 interlocking nails used to stabilize canine distal femoral fractures. Vet Surg 2006; 35:161-7. [PMID: 16472296 DOI: 10.1111/j.1532-950x.2006.00127.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To compare the structural properties of an 8 mm model 11 interlocking nail (IN) with 2 proximal and 2 distal screws (2/2) to 2 proximal and 1 distal screws (2/1) in an unstable canine fracture model. STUDY DESIGN Ex vivo biomechanical investigation. SAMPLE POPULATION Eight pairs of adult canine femurs. METHODS A simple transverse distal metaphyseal femoral fracture with a 1 cm gap was created. The unstable fracture in 1 femur was repaired with a nail with 2 distal and 2 proximal screws and the paired femur with a nail with 1 distal and 2 proximal screws. Cyclic mechanical testing in torsion was performed to assess fatigue life, peak torque, stiffness, and mode of failure. RESULTS All 2/1 IN-femoral constructs, but only 2 of eight 2/2 constructs, failed before completion of 50,000 loading cycles. The 2/2 constructs had significantly greater peak torque to failure (P = .002) and longer fatigue life (P = .00003) compared with 2/1 constructs. There were no significant differences in stiffness between 2/2 and 2/1 constructs when the non-failed constructs were compared (P > .5). All constructs failed by screw deformation. CONCLUSIONS An 8 mm model 11 IN used for fixation of unstable canine distal femoral fractures has a longer fatigue life and is stronger under torsional loads when 2 rather than 1 distal screws are placed. CLINICAL RELEVANCE When repairing unstable canine distal femoral fractures with an IN system, 2 distal screws should be inserted to avoid catastrophic implant failure before bone healing is achieved.
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Affiliation(s)
- Michael R Reems
- Department of Clinical Sciences, Colorado State University, Fort Collins, CO, USA
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17
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von Pfeil DJF, Déjardin LM, DeCamp CE, Meyer EG, Lansdowne JL, Weerts RJH, Haut RC. In vitro biomechanical comparison of a plate-rod combination-construct and an interlocking nail-construct for experimentally induced gap fractures in canine tibiae. Am J Vet Res 2006; 66:1536-43. [PMID: 16261826 DOI: 10.2460/ajvr.2005.66.1536] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare structural properties of a plate-rod combination-bone construct (PRCbc) and interlocking nail-bone construct (ILNbc) by use of an experimentally induced gap fracture in canine tibiae. SAMPLE POPULATION 12 paired canine tibiae. PROCEDURE Specimens were implanted with a plate-rod combination consisting of a 3.5-mm, limited-contact, dynamic-compression plate combined with an intramedullary rod or 6-mm interlocking nail. Ostectomy (removal of 10-mm segment) was performed. Paired constructs were loaded for bending, compression, or torsion measurements (4 constructs/group). Compliance was determined by fitting regression lines to the load-position curves at low (initial compliance) and high (terminal compliance) loads. RESULTS Bending compliances did not differ significantly between constructs. For the ILNbc, initial compliance was greater than terminal compliance in compression and torsion. Initial compliance and terminal compliance for the PRCbc were similar in compression and torsion. Initial compliance in compression and torsion was greater for the ILNbc, compared with initial compliance for the PRCbc. Maximum deformations in bending and compression were similar between constructs; however, maximum torsional angle was significantly greater for the ILNbc, compared with values for the PRCbc. CONCLUSIONS AND CLINICAL RELEVANCE The study documented that for an experimentally induced gap fracture in canine tibiae, a plate-rod combination is a significantly less compliant fixation method in torsion and compression, compared with an interlocking nail. Considering the deleterious effects of torsional deformation on bone healing, a plate-rod combination may represent a biomechanically superior fixation method, compared with an interlocking nail, for the treatment of dogs with comminuted tibial diaphyseal fractures.
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Affiliation(s)
- Dirsko J F von Pfeil
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Ml 48824, USA
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18
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Abstract
Over the past decade, many improvements to small animal internal fracture fixation have been developed, including improved fixation techniques and a more diverse selection of implants. The understanding that appropriate fixation selection is based on a plethora of biologic, mechanical, and clinical factors has also emerged. Classically, the methods of internal fracture fixation have used pins, wires, screws, and plates to rigidly stabilize fractures that have been anatomically reduced with significant disruption to the biologic fracture environment. Newer methods attempt to minimize trauma to the soft tissues surrounding a fracture and promote biologic osteosynthesis using such implants as interlocking nails and plate-rod fixations. This review provides an overview of both the traditional and current principles of small animal internal fracture fixation.
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Affiliation(s)
- Kevin S Stiffler
- Department of Small Animal Medicine and Surgery, University of Georgia, College of Veterinary Medicine, Athens, GA, USA.
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19
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Basinger RR, Suber JT. Two Techniques for Supplementing Interlocking Nail Repair of Fractures of the Humerus, Femur, and Tibia: Results in 12 Dogs and Cats. Vet Surg 2004; 33:673-80. [PMID: 15659025 DOI: 10.1111/j.1532-950x.2004.04095.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To describe 2 devices for improving stabilization of inadequately stabilized interlocking nail (ILN) repairs of the humerus, tibia, and femur in dogs and cats. STUDY DESIGN Prospective study. ANIMALS Twelve client-owned dogs and cats. METHODS Two devices to further stabilize ILN repair of inadequately stabilized diaphyseal fractures were developed. Device 1 was an axial extension for the ILN that was connected to a conventional type I external skeletal fixator (ESF) with a short connecting bar. Device 2 had hybrid ILN bolt/ESF pins that were used to lock the ILN and serve as the pins for a type I ESF. Devices were used at the initial surgery when the stability of ILN repair was considered inadequate based on palpable fracture segment movement, insufficient medullary canal filling of the ILN at the fracture site, or when the ILN was used in a buttress mode. Outcome was obtained by recheck examinations, radiography, and telephone interview. RESULTS Device 1 was applicable to fractures of the humerus and femur, but was not used for fractures of the tibia because the ILN extension would have interfered with the stifle. No gross loosening of the ILN/ESF extension connection to the ILN occurred. Device 2 was easily placed and used in the humerus, femur, and tibia. Device 2 allowed removal of the ILN interlock to one or both main fracture segments non-invasively. Clinically, both devices added stability compared with ILN repair alone. Both devices facilitated controlled destabilization of the fracture repair as healing progressed. Complications of pin tract infection, and premature hybrid bolt/ESF pin loosening resulting in premature ESF removal each occurred in 1 patient. Four of 28 hybrid ILN/ESF pins were grossly loose at 4- or 6-week postoperative recheck examinations. Outcomes were excellent (9), good (1), fair (1), and poor (1). CONCLUSIONS Inadequately stabilized ILN repair of fractures can be stabilized by use of either device, both of which also permit controlled destabilization of the repair during healing. Device 2 can be used when non-invasive removal of the ILN interlock is desired during healing. CLINICAL RELEVANCE These 2 devices should be considered as alternative methods for stabilization of inadequately stabilized ILN repairs in dogs and cats, or when controlled destabilization of an ILN fracture repair is desired.
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Affiliation(s)
- R Randy Basinger
- South Carolina Surgical Referral Service, 124 Stonemark Lane, Columbia, SC 29210, USA.
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20
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Abstract
Femur fractures occur commonly in cats and dogs following substantial trauma. Fractures of the femur may be categorized as capital physeal, femoral neck, trochanteric, subtrochanteric, diaphyseal, supracondylar or condylar or distal physeal. Most femur fractures are closed due to the heavy overlying muscle, unless due to a penetrating injury such as a gunshot wound. Femur fractures are generally not amenable to conservative repair, and some kind of internal fixation is generally required. Implant systems suitable for repair of femur fractures include bone plates, interlocking nails, plate-rod construct, lag screws, pins and wires and external fixators. Fractures may be repaired using anatomic reduction and rigid fixation or using the principles of biologic osteosynthesis. Biologic osteosynthesis is particularly effective for highly comminuted fractures because vascular supply and soft tissue attachments to bone fragments are preserved, speeding the formation of bone callus. Articular fractures should be anatomically reduced and rigidly stabilized to reduce the chance of progressive osteoarthritis.
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Affiliation(s)
- Brian Beale
- Gulf Coast Veterinary Specialists, Houston, TX 77027, USA.
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21
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Hollamby S, Dejardin LM, Sikarskie JG, Haeger J. Tibiotarsal fracture repair in a bald eagle (Haliaeetus leucocephalus) using an interlocking nail. J Zoo Wildl Med 2004; 35:77-81. [PMID: 15193078 DOI: 10.1638/02-086] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A 14-yr-old, 5.13-kg bald eagle (Haliaeetus leucocephalus) was hit by a car and presented to the Michigan State University Small Animal Clinic with an open, grade II, transverse, midshaft, Winquist-Hansen type-II-comminuted left tibiotarsal fracture. The fracture was reduced and fixation established with a 4.7-mm-diameter, 112-mm-long, four-hole veterinary intramedullary interlocking nail maintained in position by single 2-mm transcortical screws placed in the main proximal and distal fragments. The bird was weight bearing on the bandaged limb 48 hr postoperatively. Radiographs obtained 4 wk postoperatively revealed bridging callus over three of four cortices. The bird was released after 5 mo of rehabilitation.
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Affiliation(s)
- Simon Hollamby
- Department of Small Animal Clinical Sciences, Veterinary Medical Center, Michigan State University, East Lansing, Michigan 48824-1314, USA
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22
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Horstman CL, Beale BS, Conzemius MG, Evans R R. Biological Osteosynthesis Versus Traditional Anatomic Reconstruction of 20 Long-Bone Fractures Using an Interlocking Nail: 1994-2001. Vet Surg 2004; 33:232-7. [PMID: 15104629 DOI: 10.1111/j.1532-950x.2004.04034.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To observe differences in surgical and healing times as well as complication rates in dogs with a comminuted long-bone fracture stabilized with an interlocking nail (IN) using either anatomic or biologic repair. STUDY DESIGN Retrospective study. ANIMALS Twenty client-owned dogs with comminuted long-bone fractures. METHODS Medical records for dogs with fractures repaired during a 7-year period were reviewed; 20 dogs had repair with an IN nail and radiographic evidence of healing. These 20 dogs where divided into 2 groups, anatomic (11 dogs) and biological (9) repair, for statistical evaluation. Surgical and healing time and complication rates were compared between groups. RESULTS Median surgical times were: anatomic (95 minutes) and biologic (110 minutes; P=.06). Median healing times were anatomic (8 weeks) and biologic (6 weeks; P=.04). No statistical differences were observed in complication rates (the likelihood that a case required a second surgery [P=.58], the likelihood of a complication that was managed non-surgically [P=.27]). Use of a bone graft did not shorten healing times (P=.55). CONCLUSIONS Biological osteosynthesis provides clinical advantages over anatomic reconstruction with respect to a reduction in surgical and healing time without increasing complication rates. CLINICAL RELEVANCE Highly comminuted long-bone fractures can be successfully repaired using an IN without reconstructing the fracture fragments in dogs.
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Affiliation(s)
- Christopher L Horstman
- Orthopedic Research Laboratory, Department of Veterinary Clinical Sciences, Iowa State University, Ames, IA.
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23
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Duhautois B. Use of veterinary interlocking nails for diaphyseal fractures in dogs and cats: 121 cases. Vet Surg 2003; 32:8-20. [PMID: 12520485 DOI: 10.1053/jvet.2003.50008] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To report clinical outcome after use of an interlocking nail (veterinary interlocking nail [VIN]) for stabilization of diaphyseal fractures in dogs and cats. STUDY DESIGN Retrospective study. ANIMALS Seventy-eight dogs and 43 cats with diaphyseal fractures of the femur (n = 96), tibia (n = 14), or humerus (n = 11). METHODS Interlocking nails (4 mm diameter [n = 72], 6 mm [n = 25] or 8 mm [n = 24]), were used in static (n = 106) or dynamic (n = 15) fixation mode. Cerclage wires also were used in 63 (52%) cases. Data about the patient (species, breed, weight, age), characteristics of the fracture, and details of the surgery and perioperative complications were recorded. The surgeon evaluated functional outcome, and fracture healing was quantified 6 weeks (W6) and 3 months (M3) after surgery with a radiographic index. RESULTS Twelve cases had been unsuccessfully treated by another technique. Of 106 comminuted fractures, 60 were classified as unstable. Only 112 animals were evaluated at W6; 86 (77%) healed without complication and had a functional outcome considered excellent (n = 80, 93%), good (n = 5, 4%), or fair (n = 1). Twenty-six complications were noted: 16 (14%) patients did not require additional surgery and had a good or excellent outcome, whereas 10 (8%) patients needed surgical intervention to CONCLUSIONS VINs can be used to repair diaphyseal fractures of the femur, tibia, and humerus in dogs and cats provided the implants are appropriately sized for the fractured bone. The high healing rate (even with unstable fractures), associated with a functional outcome, and low complication rate support the use of VINs for these fracture types. However, a period of training and the application of basic principles are necessary to ensure successful results. CLINICAL RELEVANCE VINs should be considered as alternative technique for management of selected diaphyseal fractures of the femur, tibia, and humerus in dogs and cats.
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Moses PA, Lewis DD, Lanz OI, Stubbs WP, Cross AR, Smith KR. Intramedullary interlocking nail stabilisation of 21 humeral fractures in 19 dogs and one cat. Aust Vet J 2002; 80:336-43. [PMID: 12153056 DOI: 10.1111/j.1751-0813.2002.tb14781.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To assess the suitability of the intramedullary interlocking nail to stabilise humeral diaphyseal fractures in dogs and cats. METHOD This multi-centre study retrospectively examined medical records, between June 1994 and May 2001, of 19 dogs and one cat, in which a total of 21 humeral fractures were stabilised with intramedullary interlocking nails. RESULTS Animals ranged in body-weight from 4 to 97 kg. Eighteen (86%) of the fractures were comminuted. Adjunctive stabilisation was used in twelve (57%) fractures and bone grafts in nine (43%) fractures. A rapid return of function was noted in the majority of animals, with 14 (67%) having good or excellent function within four days of surgery. In two fractures the repair collapsed when a single proximal transcortical screw was placed cranial to the tricipital line of the humerus. This suggests that if a single transcortical screw is placed proximally the screw should be distal or caudal to the tricipital line in order to engage sufficient cortical bone. Eighteen (86%) of the fractures healed when stabilised with intramedullary interlocking nails. Three fractures did not heal. One was in a dog where a pathological fracture was temporarily stabilised with an intramedullary interlocking nail, one in a dog that died of an abdominal crisis three weeks after surgery and one in a dog in which fracture stabilisation collapsed due to incorrect implant selection. CONCLUSION Intramedullary interlocking nails are well suited to the stabilisation of humeral diaphyseal fractures in dogs and cats.
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Affiliation(s)
- P A Moses
- Veterinary Specialist Services, Underwood, Queensland
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25
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Galuppo LD, Stover SM, Aldridge A, Hewes C, Taylor KT. An in vitro biomechanical investigation of an MP35N intramedullary interlocking nail system for repair of third metacarpal fractures in adult horses. Vet Surg 2002; 31:211-25. [PMID: 11994848 DOI: 10.1053/jvet.2002.32400] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To compare monotonic mechanical properties of gap-ostectomized third metacarpal bones (MC3) stabilized with an MP35N interlocking nail system with contralateral intact bones. ANIMALS OR SAMPLE POPULATION Twenty-four pairs of cadaveric equine MC3s. METHODS Third metacarpal bones were divided into 4 mechanical testing groups (6 pairs per group): compression, palmarodorsal (PD) and mediolateral (ML) 4-point bending, and torsion. One MC3 from each pair was randomly selected as an intact specimen, and the contralateral gap ostectomized bone was stabilized with a 4-hole, 14-mm-diameter, 250-mm-long, MP35N intramedullary nail, and four, 7-mm-diameter, 60-mm-long MP35N interlocking screws (constructs). Mechanical testing properties were compared between intact specimens and constructs with a paired t test (significance set at P <.05). RESULTS Intact specimens were significantly stronger and stiffer than constructs in all testing modes except PD bending. Constructs achieved mean yield strengths that were 57% (compression), 81% (PD bending), 68% (ML bending), and 78% (torque) of intact specimens. Constructs achieved mean stiffnesses that were 53% (compression), 58% (PD bending), 41% (ML bending), and 47% (torque) of intact specimens. CONCLUSION Monotonic yield mechanical properties of MP35N intramedullary interlocking nail-stabilized, gap-ostectomized MC3 were lower than those of paired intact bones but exceeded reported in vivo loads for dorsopalmar bending and compression and estimated in vivo torsional loads. CLINICAL RELEVANCE Considering the benefits associated with intramedullary interlocking nail fixation of fractures, this system should be considered for use for repair of MC3 fractures with applicable fracture configurations.
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Affiliation(s)
- Larry D Galuppo
- J. D. Wheat Veterinary Orthopedic Research Laboratory, School of Veterinary Medicine, University of California, One Shields Avenue, Davis, CA 95616, USA
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26
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Larin A, Eich CS, Parker RB, Stubbs WP. Repair of diaphyseal femoral fractures in cats using interlocking intramedullary nails: 12 cases (1996-2000). J Am Vet Med Assoc 2001; 219:1098-104. [PMID: 11700708 DOI: 10.2460/javma.2001.219.1098] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine the outcome of femoral fractures repaired with 4.0- and 4.7-mm interlocking intramedullary nails in cats. DESIGN Retrospective study. ANIMALS 12 cats with diaphyseal femoral fractures. PROCEDURE Records of all cats in which the 4.0- and 4.7-mm interlocking nail system was used for repair of diaphyseal femoral fractures at the Animal Medical Center and Florida Veterinary Specialists between 1996 and 2000 were reviewed. Information included signalment, type of fracture, size of the implant, details of the surgery, intra- and postoperative complications, fracture healing, and clinical outcome. RESULTS Femoral fractures in 12 cats were repaired. Eleven of the fractures were comminuted, with 2 of these being open. Clinical outcome was excellent in 7 cats, good in 3, and fair in 1. One resulted in a nonunion. Complications included screw breakage (1 cat) and fracture distal to the nail (1). Fracture distal to the nail occurred from a second trauma. CONCLUSION AND CLINICAL RELEVANCE Use of the interlocking nail has been limited in cats because of the small diameter of the medullary canal. Use of the 4.0-mm nail will allow for greater application of this implant in small patients. Results of this study indicate that the 4.0- and 4.7-mm interlocking nails can be used to repair simple or comminuted diaphyseal femoral fractures in cats.
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Affiliation(s)
- A Larin
- Department of Surgery, The E & M Bobst Hospital of the Animal Medical Center, New York, NY 10021, USA
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27
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Bernarde A, Diop A, Maurel N, Viguier E. An in vitro biomechanical study of bone plate and interlocking nail in a canine diaphyseal femoral fracture model. Vet Surg 2001; 30:397-408. [PMID: 11555814 DOI: 10.1053/jvet.2001.25863] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To compare the structural properties and the interfragmentary motion in ostectomized canine femurs stabilized with either an 8-mm interlocking nail system (IN) or a 10-hole dynamic compression broad plate (DCP). ANIMAL OR SAMPLE POPULATION Ten pairs of adult canine femurs with a 25-mm mid-diaphyseal gap. METHODS Bone specimens were divided into 2 groups (10 femurs each). Left femurs were stabilized with a DCP and 8 bicortical screws; right femurs were stabilized with an IN and 3 screws. Mechanical tests were performed in eccentric axial loading and in craniocaudal bending. The testing was first conducted nondestructively and then until breakage. Structural properties, ie, stiffness, yield limits, and failure limits, were determined. Interfragmentary motion was measured during nondestructive tests with the use of an optoelectronic device. Axial, transverse, and rotational motions were calculated. Mean values of stiffness, yield and failure limits, and axial and shear motions for each fixation method were compared using a paired t test within each group (P <.05). RESULTS Mean (+/-SD) values of stiffness and failure limit were significantly higher for IN constructs than for DCP constructs in compression, while there was little difference in the results between each tested group in bending. Mean yield load values were significantly higher for IN than for DCP specimens in compression as well as in bending. The axial-motion analysis revealed significant differences between IN and DCP groups during bending tests only. The highest score of transverse motion at the gap was recorded during bending tests, and was higher for DCP than for IN specimens. There were insignificant differences between the two groups with regard to rotation around the diaphyseal axis. CONCLUSIONS AND CLINICAL RELEVANCE Structural properties and interfragmentary shear motion analysis demonstrated a much higher rigidity in the IN-bone than in the DCP-bone constructs.
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Affiliation(s)
- A Bernarde
- Laboratoire de Biomécanique, Ecole Nationale Supérieure d'Arts et Métiers, Paris, France
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28
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Radcliffe RM, Lopez MJ, Turner TA, Watkins JP, Radcliffe CH, Markel MD. An in vitro biomechanical comparison of interlocking nail constructs and double plating for fixation of diaphyseal femur fractures in immature horses. Vet Surg 2001; 30:179-90. [PMID: 11230773 DOI: 10.1053/jvet.2001.21396] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To compare the biomechanical properties of intact immature horse femurs and 3 stabilization methods in ostectomized femurs. ANIMAL OR SAMPLE POPULATION Eighteen pairs of femurs from immature horses aged 1 to 15 months, and weighing 68 to 236 kg. METHODS Thirty-four immature horse femurs were randomly assigned to 1 of 5 test groups: 1) interlocking intramedullary nail (IIN) (n = 6); 2) IIN with a cranial dynamic compression plate (I/DCP) (n = 6); 3) 2 dynamic compression plates (2DCP) (n = 8); 4) intact femurs tested to failure in lateromedial (LM) bending (n = 6); and 5) intact femurs tested to failure in caudocranial (CaCr) bending (n = 8). Mid-diaphyseal ostectomies (1 cm) were performed in all fixation constructs. Biomechanical testing consisted of 4 nondestructive tests: CaCr bending, LM bending, compression, and torsion, followed by bending to failure. All groups were tested to failure in LM bending with the exception of 1 group of intact femurs tested to failure in CaCr bending. Stiffness and failure properties were compared among groups. RESULTS The 2DCP-femur construct had greater structural stiffness in nondestructive bending than the IIN-femur construct in either LM or CaCr bending, and the I/DCP-femur construct in LM bending. Only the I/DCP and 2DCP fixations were similar to intact bone in nondestructive-bending tests. In addition, the 2DCP-femur construct had greater structural and gap torsional stiffness than the I/DCP-femur construct, and greater gap torsional stiffness than the IIN-femur construct. However, all of the fixation methods tested, including the 2DCP-femur construct, had lower structural stiffness in torsional loading compared with intact bone. No significant differences in structural stiffness were found between intact bones and femur constructs tested nondestructively in compression. In resistance to LM bending to failure, the 2DCP-femur construct was superior to the IIN-femur construct, yet similar to the I/DCP-femur construct. Also, evaluation of yield and failure loads revealed no significant differences between intact bone and any of the femur constructs tested to failure in LM bending. CONCLUSIONS In general, the 2DCP-femur construct provided superior strength and stiffness compared with the IIN and I/DCP-femur constructs under bending and torsion. CLINICAL RELEVANCE Double plating of diaphyseal comminuted femoral fractures in immature horses may be the best method of repair, because in general, it provides the greatest strength and stiffness in bending and torsion.
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Affiliation(s)
- R M Radcliffe
- Comparative Orthopaedic Research Laboratory, Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA
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29
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Abstract
A basic understanding of biomechanics, the material and structural properties of bone, and the effects that forces have on long bones enables the veterinary orthopedic surgeon to make rational decisions in selecting the most appropriate method of fracture fixation. This knowledge should enhance a surgeon's clinical ability to create a biomechanically stable environment at the fracture site that is conducive to rapid bone healing and early return to function of the patient. Furthermore, the ability to comprehend biomechanics as it pertains to fracture management enables the surgeon to scientifically critique new implant systems as they are developed with regard to their inherent ability to effectively neutralize the potential disruptive forces acting on a fracture after stabilization.
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Affiliation(s)
- R M Radasch
- Dallas Veterinary Surgical Center, Texas, USA
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30
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McLaughlin R. Internal fixation. Intramedullary pins, cerclage wires, and interlocking nails. Vet Clin North Am Small Anim Pract 1999; 29:1097-116. [PMID: 10503286 DOI: 10.1016/s0195-5616(99)50104-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
IM pins, cerclage wires, and ILNs are valuable tools for repairing long bone fractures. Successful bone healing is readily achieved with these tools but also requires aseptic technique, attention to preserving soft tissues, and proper application procedures.
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31
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Lopez MJ, Wilson DG, Vanderby R, Markel MD. An in vitro biomechanical comparison of an interlocking nail system and dynamic compression plate fixation of ostectomized equine third metacarpal bones. Vet Surg 1999; 28:333-40. [PMID: 10493637 DOI: 10.1111/j.1532-950x.1999.00333.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To compare the mechanical properties of two stabilization methods for ostectomized equine third metacarpi (MC3): (1) an interlocking nail system and (2) two dynamic compression plates. Animal or Sample Population-Ten pairs of adult equine forelimbs intact from the midradius distally. METHODS Ten pairs of equine MC3 were divided into two test groups (five pairs each): caudocranial four-point bending and torsion. Interlocking nails (6 hole, 13-mm diameter, 230-mm length) were placed in one randomly selected bone from each pair. Two dynamic compression plates one dorsally (12 hole, 4.5-mm broad) and one laterally (10 hole, 4.5-mm broad) were attached to the contralateral bone from each pair. All bones had 1 cm mid-diaphyseal ostectomies. Five construct pairs were tested in caudocranial four-point bending to determine stiffness and failure properties. The remaining five construct pairs were tested in torsion to determine torsional stiffness and yield load. Mean values for each fixation method were compared using a paired t-test within each group. Significance was set at P<.05. RESULTS Mean (+/-SEM) values for the MC3-interlocking nail composite and the MC3-double plate composite, respectively, in four-point bending were: composite rigidity, 3,454+/-407.6 Nm/rad and 3,831+/-436.5 Nm/rad; yield bending moment, 276.4+/-40.17 Nm and 433.75+/-83.99 Nm; failure bending moment, 526.3+/-105.9 Nm and 636.2+/-27.77 Nm. There was no significant difference in the biomechanical values for bending between the two fixation methods. In torsion, mean (+/-SEM) values for the MC3-interlocking nail composite and the MC3-double plate composite were: composite rigidity, 124.1+/-16.61 Nm/rad and 262.4+/-30.51 Nm/rad; gap stiffness, 222.3+/-47.32 Nm/rad and 1,557+/-320.9 Nm/rad; yield load, 94.77+/-7.822 Nm and 130.66+/-20.27 Nm, respectively. Composite rigidity, gap stiffness, and yield load for double plate fixation were significantly higher compared with interlocking nail fixation in torsion. CONCLUSIONS No significant differences in biomechanical properties were identified between an interlocking nail and double plating techniques for stabilization of ostectomized equine MC3 in caudocranial four-point bending. Double plating fixation was superior to interlocking nail fixation in torsion.
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Affiliation(s)
- M J Lopez
- Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin, Madison 53706, USA
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32
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Endo K, Nakamura K, Maeda H, Matsushita T. Interlocking intramedullary nail method for the treatment of femoral and tibial fractures in cats and small dogs. J Vet Med Sci 1998; 60:119-22. [PMID: 9492372 DOI: 10.1292/jvms.60.119] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We have developed an interlocking intramedullary nail method for the treatment of femoral and tibial fractures and used this method for the treatment of 7 cats and 6 dogs with these fractures. The interlocking nails, with a diameter of 4-6 mm and length of 60-140 mm, have holes at 10 mm intervals for screwing. The nail placed on the insertion device was inserted into the marrow cavity from the end of the fractured bone in the usual procedures for intramedullary fixation, then fixed by screws at the distal and proximal ends with a jig which was also attached to the insertion device. Animals were able to bear weight on the treated legs within three days, and the prognosis was excellent.
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Affiliation(s)
- K Endo
- Endo Animal Hospital, Tochigi, Japan
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