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Filardi V, Vaishya R. Comparative Finite Element (FE) Analysis of the Mechanical Behavior in an Innovative Nitinol Staple for Arthrodesis in Distal Interphalangeal Joint. J Hand Microsurg 2024; 16:100040. [PMID: 38855509 PMCID: PMC11144644 DOI: 10.1055/s-0043-1769091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2024] Open
Abstract
Objective Osteoarthritis (OA) is a source of significant limitations for individuals, health systems, and economies. The most common complications of OA are often associated with risk factors related to chronic diseases, cardiovascular disease, and depression. In this article, a new kind of staple is proposed, designed to provide better strength when subjected to bending and torque loads. Methods This innovative staple has been numerically tested and compared to a MEMOFIX staple by Smith + Nephew, in order to evaluate its mechanical behavior. The radius and ulna were fixed at the lower extremity, while the distal interphalangeal of the little finger was loaded with a bending load of 50 N and a torque moment of 500 N/mm2. Results For the bending load, a maximum value of stress of 120 MPa in the traditional staple, while 90 MPa are registered in the innovative one. The torsional load produces a value of 107 MPa in the traditional staple and 85 MPa in the innovative one. Conclusion Computational simulations showed the biomechanical performance of a new type of nitinol staple compared with a traditional one. This staple is designed with an elliptical shape in order to support different kinds of loads. Our results confirm an optimal mechanical behavior, compared to the traditional staple, in terms of the evaluated Equivalent Von Mises stress; also the contact force exerted by the innovative staple was increased.
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Affiliation(s)
- V. Filardi
- Administrative Department of Research and Internationalization, University of Messina, Messina, Italy
| | - R. Vaishya
- Department of Orthopaedics, Indraprastha Apollo Hospital, New Delhi, India
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Sleiman A, Bejcek C, Nestler A, Revelt N, Thuppal S, Mills A, Gardner M. The history of orthopaedic use of nitinol compression staples. Injury 2023; 54:111036. [PMID: 37769424 DOI: 10.1016/j.injury.2023.111036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 08/28/2023] [Accepted: 09/08/2023] [Indexed: 09/30/2023]
Abstract
INTRODUCTION The use of nitinol continuous compression staples has shown clinical utility in the management of various orthopaedic injuries. While literature is most robust in the realm of foot/ankle and spine surgery, the use of nitinol staples has been documented in fixation of wrist, olecranon, patella, and pelvis fractures. METHODOLOGY A narrative review was conducted by searching three online databases - PubMed, Web of Science, and Cochrane using the terms "Nitinol" and "Staple" published between 2003 and 2023. A total of 42 articles met inclusion/exclusion criteria and were included in this review. REVIEW Literature outside of foot/ankle and spine surgery is largely limited to biomechanical studies, case reports, and finite element analyses. The literature is summarized within this review by anatomic location including foot/ankle, lower extremity, hand, upper extremity, spine, and pelvis. CONCLUSION Existing literature demonstrates a diverse array of applications for nitinol continuous compression staples in both axial and appendicular orthopaedic care. Advantages of these implants include ease of application, ability to capture small bony fragments, continuous compression across a fracture or arthrodesis, and full coaptation which maximizes the surface area for healing and/or fusion.
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Affiliation(s)
- Anthony Sleiman
- Division of Orthopedics and Rehabilitation, Department of Surgery, Southern Illinois University School of Medicine, 801 N. Rutledge St, Springfield, IL 62702, United States
| | - Christopher Bejcek
- Division of Orthopedics and Rehabilitation, Department of Surgery, Southern Illinois University School of Medicine, 801 N. Rutledge St, Springfield, IL 62702, United States
| | - Anthony Nestler
- Division of Orthopedics and Rehabilitation, Department of Surgery, Southern Illinois University School of Medicine, 801 N. Rutledge St, Springfield, IL 62702, United States
| | - Nicolas Revelt
- Division of Orthopedics and Rehabilitation, Department of Surgery, Southern Illinois University School of Medicine, 801 N. Rutledge St, Springfield, IL 62702, United States
| | - Sowmyanarayanan Thuppal
- Division of Orthopedics and Rehabilitation, Department of Surgery, Southern Illinois University School of Medicine, 801 N. Rutledge St, Springfield, IL 62702, United States
| | - Andrew Mills
- Division of Orthopedics and Rehabilitation, Department of Surgery, Southern Illinois University School of Medicine, 801 N. Rutledge St, Springfield, IL 62702, United States; Springfield Clinic Orthopedic Surgery, 800 N 1st St, Springfield, IL 62702, United States
| | - Matthew Gardner
- Division of Orthopedics and Rehabilitation, Department of Surgery, Southern Illinois University School of Medicine, 801 N. Rutledge St, Springfield, IL 62702, United States; Springfield Clinic Orthopedic Surgery, 800 N 1st St, Springfield, IL 62702, United States.
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Posey SL, Gaston RG. Staple Technology for Fracture Fixation and Joint Arthrodesis. Hand Clin 2023; 39:505-513. [PMID: 37827603 DOI: 10.1016/j.hcl.2023.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/14/2023]
Abstract
The use of staple technology in the upper extremity has continued to evolve with the development of shape-memory alloys (SMAs) such as Nitinol that display superelastic properties that can be exploited for persistent compression. Clinical and biomechanical studies support the use of SMA staples for upper extremity fracture fixation and joint arthrodesis. To optimize biomechanical strength and clinical outcomes, it is recommended to place two staples, if possible, at the site of interest as well as to trough the staples to prevent hardware prominence.
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Affiliation(s)
- Samuel L Posey
- Department of Orthopaedic Surgery, Atrium Health, 1000 Blythe Boulevard, Charlotte, NC 28203, USA
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Zhang M, Jiang W, Wang ZX, Zhou ZM. Using shape-memory alloy staples to treat comminuted manubrium sterni fractures: A case report. World J Clin Cases 2023; 11:7386-7392. [PMID: 37969455 PMCID: PMC10643072 DOI: 10.12998/wjcc.v11.i30.7386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 09/22/2023] [Accepted: 10/08/2023] [Indexed: 10/25/2023] Open
Abstract
BACKGROUND Comminuted manubrium sterni fractures are rare, and internal fixation methods are limited. This report explored a practical and feasible method of internal fixation for comminuted manubrium sterni fractures. CASE SUMMARY A 17-year-old female was injured in a car accident for which she underwent debridement and suturing of her head and anterior chest wounds in another hospital. Eight days later, the patient was transferred to our hospital for surgical treatment. The manubrium sterni was found intraoperatively to be split into three irregular fragments with obvious overlap and separation displacement. Meanwhile, a manubriosternal joint dislocation and left first rib cartilage fracture were observed. The retraction force of the shape-memory alloy staples was used to pull the fracture fragments together. Two more titanium locking plates were then used to fix the manubrium sterni and corpus sterni longitudinally, and the left first rib cartilage fracture was repositioned and fixed with a titanium locking plate. A postoperative computed tomography scan showed reduced and rigid fixation of the comminuted manubrium sterni fractures. The patient recovered well with no significant complaints of discomfort. The patient was discharged 10 days postoperatively after the stitches had been removed. CONCLUSION Shape-memory alloy staples had the advantage of being safe and effective during the repositioning and internal fixation of comminuted manubrium sterni fractures. Therefore, they provided a new surgical option for comminuted manubrium sterni fractures.
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Affiliation(s)
- Min Zhang
- Department of Thoracic Surgery, Central Hospital Affiliated to Shenyang Medical College, Shenyang 110024, Liaoning Province, China
| | - Wei Jiang
- Department of Thoracic Surgery, Central Hospital Affiliated to Shenyang Medical College, Shenyang 110024, Liaoning Province, China
| | - Ze-Xue Wang
- Department of Thoracic Surgery, Central Hospital Affiliated to Shenyang Medical College, Shenyang 110024, Liaoning Province, China
| | - Zhi-Ming Zhou
- Department of Thoracic Surgery, Central Hospital Affiliated to Shenyang Medical College, Shenyang 110024, Liaoning Province, China
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Jang SR, Suh IW, Heng L. Nanoscale Polishing Technique of Biomedical Grade NiTi Wire by Advanced MAF Process: Relationship between Surface Roughness and Bacterial Adhesion. J Funct Biomater 2023; 14:jfb14040177. [PMID: 37103267 PMCID: PMC10143815 DOI: 10.3390/jfb14040177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 03/22/2023] [Accepted: 03/22/2023] [Indexed: 04/28/2023] Open
Abstract
Nitinol (NiTi), an alloy of nickel and titanium, wires are an important biomedical material that has been used in catheter tubes, guidewires, stents, and other surgical instruments. As such wires are temporarily or permanently inserted inside the human body, their surfaces need to be smoothed and cleaned in order to prevent wear, friction, and adhesion of bacteria. In this study, NiTi wire samples of micro-scale diameters (i.e., Ø 200 μm and Ø 400 μm) were polished by an advanced magnetic abrasive finishing (MAF) process using a nanoscale polishing method. Furthermore, bacterial adhesion (i.e., Escherichia coli (E. coli), and Staphylococcus aureus (S. aureus)) to the initial and final surfaces of NiTi wires were investigated and compared in order to assess the impact of surface roughness on bacterial adhesion to the surfaces of NiTi wires. The finding revealed that the surfaces of NiTi wires were clean and smooth with a lack of particle impurities and toxic components on the final surface polished using the advanced MAF process. The surface roughness Ra values of the Ø 200 μm and Ø 400 μm NiTi wires were smoothly enhanced to 20 nm and 30 nm from the 140 nm and 280 nm initial surface roughness values. Importantly, polishing the surfaces of a biomedical material such as NiTi wire to nano-level roughness can significantly reduce bacterial adhesion on the surface by more than 83.48% in the case of S. aureus, while in the case of E. coli was more than 70.67%.
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Affiliation(s)
- Se Rim Jang
- Division of Mechanical Design Engineering, College of Engineering, Jeonbuk National University, 567, Baekje-daero, Jeonju-si 54896, Republic of Korea
| | - Il Won Suh
- Department of Bionanotechnology and Bioconvergence Engineering, Graduate School, Jeonbuk National University, Jeonju 561-656, Republic of Korea
| | - Lida Heng
- Division of Mechanical Design Engineering, College of Engineering, Jeonbuk National University, 567, Baekje-daero, Jeonju-si 54896, Republic of Korea
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Horner K, Summerhays B, Fiala K, Schweser KM. Radiographic Evaluation of Isolated Continuous Compression Staples for Akin Osteotomy Fixation. J Foot Ankle Surg 2022; 62:487-491. [PMID: 36513576 DOI: 10.1053/j.jfas.2022.11.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 11/01/2022] [Accepted: 11/20/2022] [Indexed: 11/26/2022]
Abstract
Continuous compression implants (nitinol staples) are gaining popularity secondary to their lower profile, less demanding technique, and less surgical dissection. Biomechanical support exists; however, clinical data is limited in the foot/ankle. This study's purpose is to determine the efficacy of nitinol staples to achieve stable, bony healing in Akin osteotomies and examine their clinical outcomes, complications, re-operations, and pain scores. We performed a retrospective chart review on 90 patients (93 osteotomies) who underwent an Akin osteotomy using a nitinol staple over a 2-year period. Radiographs were randomized and independently reviewed by 3 blinded foot and ankle surgeons. Osteotomies were deemed healed if greater than 50% of the osteotomy contained bridging bone, partially healed as less than 50% bridging bone, and nonunion as no healing, broken hardware, or loss of reduction. Visual analog scale pain scores were analyzed. Radiographic union was seen in 98.9% of Akin osteotomies (92/93), with no loss of reduction or broken staples (0/95). Only 3.2% (3/93) of patients returned to the operating room unplanned: 1 infection (1.1%), 1 symptomatic hardware removal (1.1%), and 1 traumatic disruption of fixation (1.1%). Postoperative pain scores were significantly lower than preoperative. Staples are lower profile and technically less demanding compared to headed screws, plates, and tension band constructs. They offer continuous compression of the osteotomy and are rigid enough to maintain reduction. Based on the findings of this paper, the use of staples provides robust and stable fixation for Akin osteotomies and has low complication and high healing rates.
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Affiliation(s)
- Kevin Horner
- School of Medicine, University of Missouri, Columbia, MO
| | | | - Kyle Fiala
- Department of Orthopaedic Surgery, University of Missouri, Columbia, MO
| | - Kyle M Schweser
- Department of Orthopaedic Surgery, University of Missouri, Columbia, MO.
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Schafer KA, Baldini T, Hamati M, Backus JD, Hunt KJ, McCormick JJ. Two Orthogonal Nitinol Staples and Combined Nitinol Staple-Screw Constructs for a First Metatarsophalangeal Joint Arthrodesis: A Biomechanical Cadaver Study. Foot Ankle Int 2022; 43:1493-1500. [PMID: 36036524 DOI: 10.1177/10711007221119157] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND End-stage hallux metatarsophalangeal (MTP) joint arthritis is commonly treated with arthrodesis using stainless steel or titanium implants. These implants provide static compression that is maximal at the time of implant insertion. Alternatively, nitinol staples are capable of dynamic compression. They have most frequently been used for midfoot arthrodesis procedures. However, their biomechanical performance during hallux MTP arthrodesis has not been described. METHODS 8 matched pairs of cadaveric feet (4 female, 4 male) were prepared for hallux MTP arthrodesis using cup and cone reamers. Cadaveric pairs were then instrumented with either (1) a transarticular lag screw and dorsal nitinol staple or (2) orthogonal nitinol staples placed dorsally and medially. Walking in a short leg cast for 6 weeks was simulated by applying 90-N forces at 3 Hz to the plantar proximal phalanx for up to 250 000 cycles. Failure was defined as catastrophic implant failure or plantar gapping beyond 7 mm. RESULTS 15 of 16 specimens failed cyclic loading. All 8 specimens fixed with orthogonal staples failed at an average of 37 ± 81 cycles. 7 of 8 specimens fixed with a dorsal staple and crossed screw failed at 14 900 ± 39 000 cycles. Collectively, 5 specimens failed because of bone fracture (1 in orthogonal staples, 4 in staple-screw group) and 10 failed because of excessive gap formation (7 in orthogonal staples, 3 in staple-screw group). The number of cycles to failure was significantly lower (P = .0469) in the orthogonal staple constructs compared with the dorsal staple and crossed screw constructs. CONCLUSION The tested constructs permit significant motion at the first MTP fusion surface during simulated protected weightbearing. Although multiple in vivo factors should be considered when extrapolating results from this cadaveric study, this motion may result in clinical failure with early postoperative weightbearing protocols. CLINICAL RELEVANCE We report the first biomechanical evaluation of hallux MTP arthrodesis using modern nitinol staples in 2 separate constructs.
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Affiliation(s)
- Kevin A Schafer
- Department of Orthopedic Surgery, Washington University in St Louis, St Louis, MO, USA
| | - Todd Baldini
- Department of Orthopaedic Surgery, University of Colorado School of Medicine, Aurora, CO, USA
| | - Mary Hamati
- Department of Orthopaedic Surgery, University of Colorado School of Medicine, Aurora, CO, USA
| | - Jonathon D Backus
- Department of Orthopedic Surgery, Washington University in St Louis, St Louis, MO, USA
| | - Kenneth J Hunt
- Department of Orthopaedic Surgery, University of Colorado School of Medicine, Aurora, CO, USA
| | - Jeremy J McCormick
- Department of Orthopedic Surgery, Washington University in St Louis, St Louis, MO, USA
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Safranski DL, Chapman SC, Wee ZR, Lareau CR, Ritter ZT, Seybold JD, Kwon JY. Effect of Bone Quality and Leg Depth on the Biomechanical Performance of a Nitinol Staple. J Foot Ankle Surg 2022; 61:93-98. [PMID: 34275718 DOI: 10.1053/j.jfas.2021.06.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 06/15/2021] [Indexed: 02/03/2023]
Abstract
The use of Nitinol compression staples has increased in foot and ankle procedures due to their ease of delivery and ability to offer sustained, dynamic compression. Prior biomechanical studies have predominantly examined mechanical performance in healthy bone models without investigating the effect of unicortical versus bicortical fixation. The purpose of this study was to examine the effect of bone quality and staple leg depth on the biomechanical performance of Nitinol staples in a bicortical bone model. Two-legged Nitinol staples were implanted in bicortical sawbone of 2 densities. Two different leg depths were tested to simulate unicortical versus bicortical fixation. Interfacial compressive forces, interfacial compression area, torsional strength, and shear strength were measured for each group. The effect of leg depth was minimal compared to the effect of sawbone density on the mechanical performance of Nitinol staples. Interfacial compressive force and interfacial compression areas were greater in the low density bone model, while torsional strength and shear strength were greater in the normal density bone model. Nitinol staple's mechanical performance is highly dependent upon bone quality and less dependent on whether staple legs terminate in cancellous versus cortical bone. Low density bone allows for a higher compressive interfacial area to be imparted by the staple. Staples in normal density bone are able to resist torsion and shear deformation more readily than staples in low density bone. Bone density may have a greater effect on the Nitinol staple's stability and compressive capability in vivo as compared to unicortical versus bicortical leg fixation.
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Affiliation(s)
- David L Safranski
- Director of Basic Research, MedShape, Inc., School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA.
| | | | - Zong-Rui Wee
- Engineering Intern, Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA
| | - Craig R Lareau
- Foot and Ankle Surgeon, New England Orthopedic Surgeons, Springfield, MA
| | - Zachary T Ritter
- Chief, Podiatric Surgery, University of Pittsburgh Medical Center Susquehanna, Williamsport, PA
| | | | - John Y Kwon
- Chief, Division of Foot and Ankle Surgery, Harvard Medical School; Beth Israel Deaconess Medical Center, Boston, MA
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Curenton TL, Davis BL, Darnley JE, Weiner SD, Owusu-Danquah JS. Assessing the biomechanical properties of nitinol staples in normal, osteopenic and osteoporotic bone models: A finite element analysis. Injury 2021; 52:2820-2826. [PMID: 34404510 DOI: 10.1016/j.injury.2021.08.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 07/12/2021] [Accepted: 08/02/2021] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Bone staples are internal fixation devices that are frequently used in the foot, ankle, and hand to provide stabilization. Fixation stability is vital after fusion or fracture surgeries to ensure proper bone healing. Patients undergoing surgeries that require fixation to keep bones aligned and stable may present with diminishing bone mechanical properties, and this may compromise the ability of the fixation hardware to maintain a stable construct. The purpose of this study was to investigate the mechanical performance of shape memory and superelastic nitinol bone staples with different bridge geometries in normal, osteopenic, and osteoporotic bone models. Contact forces and maximum principal stress and strain in the bone were recorded. METHODS Finite element simulations of a bone staple fixation procedure were performed to examine the initial and post-surgery contact force, as well as the maximum principal stress and strain of 15 mm bridge and 20 mm bridge staple-bone constructs. RESULTS Shape memory nitinol staples exhibited higher contact forces compared to superelastic nitinol staples. Nitinol bone staples with 20 mm bridge lengths displayed higher contact forces and lower stresses in all bone types, as well as lower strains in osteoporotic bone models compared to nitinol staples with a 15 mm bridge length. CONCLUSION Nitinol bone staple constructs with 20 mm bridge length staples provide higher contact forces and display lower stresses in the bone than 15 mm bridge staple-bone constructs, which may be beneficial in bone with diminishing mechanical properties. Both superelastic and shape memory effect nitinol staples provide adequate compression and stress relief. However, if osteopenia is present, shape memory effect nitinol staples with a 20 mm bridge length may provide more stress relief and compression, if the bone anatomy allows.
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Affiliation(s)
- Tanetta L Curenton
- Department of Chemical and Biomedical Engineering, Cleveland State University, Cleveland, OH 44115, USA
| | - Brian L Davis
- Department of Mechanical Engineering, Cleveland State University, Cleveland, OH 44115, USA
| | - James E Darnley
- Department of Orthopaedic Surgery, Summa Health System, Akron, OH 44304, USA
| | - Scott D Weiner
- Department of Orthopaedic Surgery, Summa Health System, Akron, OH 44304, USA
| | - Josiah S Owusu-Danquah
- Department of Civil and Environmental Engineering, Cleveland State University, Cleveland, OH 44115, USA.
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Examining the novel use of continuous compression implants in clavicle reconstruction: A biomechanical study. Clin Biomech (Bristol, Avon) 2021; 88:105437. [PMID: 34311318 DOI: 10.1016/j.clinbiomech.2021.105437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 06/15/2021] [Accepted: 07/15/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Current implants for clavicle fractures are known to cause poor cosmesis and irritation, which may require implant removal. Low-profile shape-memory staples provide an attractive alternative, but their biomechanical utility in clavicle reconstruction is unknown. We hypothesized that shape-memory reconstructions would be more compliant compared to traditional constructs but would also outperform conventional plates during cyclic loading to failure. METHODS This study was performed with 36 synthetic clavicles and 12 matched pairs of cadaveric specimens. The synthetic study tested four reconstructions: a single superiorly placed staple (n = 6), a single anteroinferiorly-placed staple (n = 6), a 3.5 mm reconstruction plate (n = 12), and two orthogonally placed staples (n = 12). The cadaveric study tested three constructs: reconstruction plate (n = 8), two orthogonal staples (n = 8), and a 2.7 mm reconstruction plate combined with a superior staple (n = 8). Non-destructive 4-point bending, compression, and torsion assays were performed prior to destructive cantilever bending and cyclic torsion tests. FINDINGS The single staple and double staple groups demonstrated significantly decreased resistance to bending (p < 0.001) and torsion (p ≤ 0.027) when compared to reconstruction plate groups. The double staple group sustained significantly fewer cycles to failure than the reconstruction plate group in cyclic torsional tests (p = 0.012). The synthetic models produced higher stiffness and failure mechanisms that were completely different from cadaveric specimens. INTERPRETATION Shape memory alloy implants provided inadequate stiffness for clavicle fixation but may have utility in other orthopaedic applications when used as a supplementary compression device in conjunction with traditional plated constructs. Synthetic bones have limited capacity for modeling fragility fractures.
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Mahenthiran A, Kacena-Merrell E, Chen WW, Lim BH, Dineen H. Nitinol Staples for Olecranon Osteotomy Fixation, Juxtacortical Versus Inset, Effect on Biomechanical Stability. JOURNAL OF HAND SURGERY GLOBAL ONLINE 2021; 3:172-175. [PMID: 35415560 PMCID: PMC8991424 DOI: 10.1016/j.jhsg.2021.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 03/04/2021] [Indexed: 11/29/2022] Open
Abstract
Purpose Hardware prominence is a concern in the fixation of olecranon osteotomies. Staple fixation has provided low-profile secure fixation in other areas of orthopedics. Without insetting, staples still have subcutaneous prominence. This study examines whether nitinol staples, when inset into bone via cortical notching, in an olecranon osteotomy can provide fixation strength sufficient for daily activities. Methods Olecranon osteotomies were created in 8 cadaver arms and fixed with 2 nitinol staples. For inset and juxtacortical (noninset) staples, a micrometer measured the displacement between preplaced proximal and distal wires for 3 increasing loads: 0 N, 15 N, and 150 N. This measurement reflected the loss of osteotomy compression. We placed each arm in a pneumatic machine that flexed the elbow from 0° to 90° for 500 cycles at each load. We performed a 2-tailed t test (α value 0.05, β value 0.2) to evaluate for differences in the loss of compression between inset and noninset nitinol staples. Results We performed the displacement measurement procedure for both staple types at each of the 3 loads. At 0 N, the average displacement of inset was 0 mm and that of noninset was 0.02 mm. At 15 N, the average displacement of inset was 0.02 mm and that of noninset was 0.04 mm. At 150 N, the average displacement of inset was 0.05 mm and that of noninset was 0.09 mm. When comparing the displacement at the 3 force loads, there were no statistically significant differences between the staple types (P = .323). Conclusions This study shows that inset staples do not considerably weaken osteotomy fixation with nitinol staples. Thus, nitinol staples may provide a low-profile, operatively-efficient fixation method compared with tension-band or screw-and-plate fixation methods for olecranon osteotomies. Future research can include comparing staples with plate constructs. Type of study/level of evidence: Therapeutic III.
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Affiliation(s)
| | - Ethan Kacena-Merrell
- Indiana Hand to Shoulder Center, Indianapolis, IN
- Corresponding author: Ethan Kacena-Merrell, Indiana Hand to Shoulder Center, 6584 Regents Park Drive, Zionsville, IN 46077.
| | | | - Boon Him Lim
- Indiana Hand to Shoulder Center, Indianapolis, IN
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