scholarly journals Biomechanical Strength of Retrograde Fixation in Proximal Third Scaphoid Fractures

Hand ◽  
2018 ◽  
Vol 14 (6) ◽  
pp. 760-764 ◽  
Author(s):  
Charles A. Daly ◽  
Allison L. Boden ◽  
William C. Hutton ◽  
Michael B. Gottschalk
Keyword(s):  
Cyclic Loading ◽  
Scaphoid Fracture ◽  
Maximum Load ◽  
Vascular Supply ◽  
Proximal Pole ◽  
Wrist Fractures ◽  
Scaphoid Fractures ◽  
Screw Length ◽  
Load To Failure ◽  
Biomechanical Strength

Background: Current techniques for fixation of proximal pole scaphoid fractures utilize antegrade fixation via a dorsal approach endangering the delicate vascular supply of the dorsal scaphoid. Volar and dorsal approaches demonstrate equivalent clinical outcomes in scaphoid wrist fractures, but no study has evaluated the biomechanical strength for fractures of the proximal pole. This study compares biomechanical strength of antegrade and retrograde fixation for fractures of the proximal pole of the scaphoid. Methods: A simulated proximal pole scaphoid fracture was produced in 22 matched cadaveric scaphoids, which were then assigned randomly to either antegrade or retrograde fixation with a cannulated headless compression screw. Cyclic loading and load to failure testing were performed and screw length, number of cycles, and maximum load sustained were recorded. Results: There were no significant differences in average screw length (25.5 mm vs 25.6 mm, P = .934), average number of cyclic loading cycles (3738 vs 3847, P = .552), average load to failure (348 N vs 371 N, P = .357), and number of catastrophic failures observed between the antegrade and retrograde fixation groups (3 in each). Practical equivalence between the 2 groups was calculated and the 2 groups were demonstrated to be practically equivalent (upper threshold P = .010). Conclusions: For this model of proximal pole scaphoid wrist fractures, antegrade and retrograde screw configuration have been proven to be equivalent in terms of biomechanical strength. With further clinical study, we hope surgeons will be able to make their decision for fixation technique based on approaches to bone grafting, concern for tenuous blood supply, and surgeon preference without fear of poor biomechanical properties.

scholarly journals Effect of Screw Length and Geometry on Interfragmentary Compression in a Simulated Proximal Pole Scaphoid Fracture Model

Hand ◽  
2018 ◽  
Vol 15 (3) ◽  
pp. 378-383
Author(s):  
Samik Patel ◽  
Juan M. Giugale ◽  
Richard E. Debski ◽  
John R. Fowler
Keyword(s):  
Analysis Of Variance ◽  
Scaphoid Fracture ◽  
Fracture Site ◽  
Proximal Pole ◽  
Scaphoid Fractures ◽  
Screw Length ◽  
Significant Difference ◽  
Headless Compression Screws ◽  
With Screws ◽  
Interfragmentary Compression

Background: The objective of this study was to determine interfragmentary compression forces based on screw length and geometry for simulated proximal scaphoid fractures. Methods: Sixty-four foam model simulated fractures were stabilized with screws of various length (10 mm, 18 mm, 20 mm, or 24 mm) and geometry (central threadless or fully threaded) across a proximal fracture. Interfragmentary compression was measured at the simulated fracture site upon fixation. An independent sample t test and 1-way analysis of variance were performed to assess differences in interfragmentary compression. Results: Fixation utilizing a 10-mm screw generated significantly less interfragmentary compression than fixation utilizing a 20-mm or 24-mm screw. When accounting for both screw length and geometry, an 18-mm central threadless screw generated greater interfragmentary compression than a 20-mm and 24-mm fully threaded screw; there was no significant difference in compression between an 18-mm and 24-mm central threadless screw. Conclusions: The design of headless compression screws allows for maximal interfragmentary compression at the screw midpoint; we questioned whether a short screw centered on the fracture site resulted in superior compression to a longer, noncentered screw. Our data suggest that centering a small screw (10 mm) along a proximal fracture generates significantly less interfragmentary compression than a longer, noncentered screw. Our results demonstrate that balance between maximizing screw length and centering the screw on the fracture is vital toward maximizing interfragmentary compression for the fixation of proximal third scaphoid fractures.

scholarly journals Impact of Screw Length on Proximal Scaphoid Fracture Biomechanics

2019 ◽  
Vol 08 (05) ◽  
pp. 360-365 ◽  
Author(s):  
Samik Patel ◽  
Juan Giugale ◽  
Nathan Tiedeken ◽  
Richard E. Debski ◽  
John R. Fowler
Keyword(s):  
Cyclic Loading ◽  
Fracture Fixation ◽  
Ultimate Load ◽  
Scaphoid Fracture ◽  
Fracture Site ◽  
Compression Screw ◽  
Headless Compression Screw ◽  
Scaphoid Fractures ◽  
Screw Length ◽  
Significant Difference

Background Proximal scaphoid fractures display high nonunion rates and increased revision cases. Waist fracture fixation involves maximizing screw length within the cortex; however, the optimal screw length for proximal scaphoid fractures remains unknown. Purpose The main purpose of this article is to compare stiffness and ultimate load for proximal scaphoid fracture fixation of various headless compression screw lengths. Methods Eighteen scaphoids underwent an osteotomy simulating a 7 mm oblique proximal fracture. Screws of three lengths (10, 18, and 24 mm) were randomly assigned for fixation. Each specimen underwent cyclic loading with stiffness calculated during the last loading cycle. Specimens that withstood cyclic loading were loaded to failure. Results No significant difference in stiffness between screw lengths was found. Ultimate load was significantly impacted by the screw length. A significant difference in ultimate load between a 10 and 24 mm screw was found; however, no significant difference occurred in ultimate load between an 18 and 24 mm screw. Conclusions No significant difference in stiffness between all groups could be due to similarities in purchase in the proximal aspect. The 10 mm screw withstanding less ultimate load compared to the 24 mm screw could be due to the 10 mm screw gaining less purchase on either side of the fracture site compared to the 24 mm screw. Lack of significant difference in ultimate load between the 18 and 24 mm screw could be occurring because the fracture site is closer to the 18 mm screw midpoint, as distal threads are engaged closer to the fracture. Clinical Relevance Maximizing screw length may not provide superior fixation biomechanically compared with fixation utilizing a 6 mm shorter screw for proximal scaphoid fractures.

scholarly journals Diagnostic accuracy of history taking, physical examination and imaging for phalangeal, metacarpal and carpal fractures: a systematic review update.

2019 ◽  
Author(s):  
Patrick Krastman ◽  
Nina M. Mathijssen ◽  
Sita M.A. Bierma-Zeinstra ◽  
Gerald Kraan ◽  
Jos Runhaar
Keyword(s):  
Physical Examination ◽  
Diagnostic Accuracy ◽  
Predictive Value ◽  
Scaphoid Fracture ◽  
Radiological Examination ◽  
Supporting Evidence ◽  
History Taking ◽  
Wrist Fractures ◽  
Scaphoid Fractures ◽  
Work Up

Abstract Background The standard diagnostic work-up for hand and wrist fractures consists of history taking, physical examination and imaging if needed, but the supporting evidence for this work-up is limited. The purpose of this study was to systematically examine the diagnostic accuracy of tests for hand and wrist fractures. Methods A systematic search for relevant studies was performed. Methodological quality was assessed and sensitivity (Se), specificity (Sp), accuracy, positive predictive value (PPV) and negative predictive value (NPV) were extracted from the eligible studies. Results Of the 35 eligible studies, one described the diagnostic accuracy of history taking for hand and wrist fractures. Physical examination with or without radiological examination for diagnosing scaphoid fractures (five studies) showed Se, Sp, accuracy, PPV and NPV ranging from 15-100%, 13-98%, 55-73%, 14-73% and 75-100%, respectively. Physical examination with radiological examination for diagnosing other carpal bone fractures (one study) showed a Se of 100%, with the exception of the triquetrum (75%). Physical examination for diagnosing phalangeal and metacarpal fractures (one study) showed Se, Sp, accuracy, PPV and NPV ranging from 26-55%, 13-89%, 45-76%, 41-77% and 63-75%, respectively. Imaging modalities of scaphoid fractures showed predominantly low values for PPV and the highest values for Sp and NPV (24 studies). Magnetic Resonance Imaging (MRI), Computed Tomography (CT), Ultrasonography (US) and Bone Scintigraphy (BS) were comparable in diagnostic accuracy for diagnosing a scaphoid fracture, with an accuracy ranging from 85-100%, 79-100%, 49-100% and 86-97%, respectively. Imaging for metacarpal and finger fractures showed Se, Sp, accuracy, PPV and NPV ranging from 73-100%, 78-100%, 70-100%, 79-100% and 70-100%, respectively. Conclusions Only one study was found on the diagnostic accuracy of history taking for hand and wrist fractures in the current review. Physical examination was of moderate use for diagnosing a scaphoid fracture and of limited use for diagnosing phalangeal, metacarpal and remaining carpal fractures. MRI, CT and BS were found to be moderately accurate for the definitive diagnosis of clinically suspected carpal fractures.

The morphology of proximal pole scaphoid fractures: implications for optimal screw placement

2017 ◽  
Vol 43 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Timothy J. Luchetti ◽  
Youssef Hedroug ◽  
John J. Fernandez ◽  
Mark S. Cohen ◽  
Robert W. Wysocki
Keyword(s):  
Sagittal Plane ◽  
Fracture Line ◽  
Screw Thread ◽  
Proximal Pole ◽  
Screw Insertion ◽  
Scaphoid Fractures ◽  
Starting Point ◽  
Screw Length ◽  
Sagittal Image ◽  
The Ideal

The purpose of this study was to measure the radiographic parameters of proximal pole scaphoid fractures, and calculate the ideal starting points and trajectories for antegrade screw insertion. Computed tomography scans of 19 consecutive patients with proximal pole fractures were studied using open source digital imaging and communications in medicine (DICOM) imaging measurement software. For scaphoid sagittal measurements, fracture inclination was measured with respect to the scaphoid axis. The ideal starting point for a screw in the proximal pole fragment was then identified on the scaphoid sagittal image that demonstrated the largest dimensions of the proximal pole, and hence the greatest screw thread purchase. Measurements were then taken for a standard screw trajectory in the axis of the scaphoid, and a trajectory that was perpendicular to the fracture line. The fracture inclination in the scaphoid sagittal plane was 25 (SD10) °, lying from proximal palmar to dorsal distal. The fracture inclination in the coronal plane was 9 (SD16) °, angling distal radial to proximal ulnar with reference to the coronal axis of the scaphoid. Using an ideal starting point that maximized the thread purchase in the proximal pole, we measured a maximum screw length of 20 (SD 2) mm when using a screw trajectory that was perpendicular to the fracture line. This was quite different from the same measurements taken in a trajectory in the axis of the scaphoid. We also identified a mean distance of approximately 10 mm from the dorsal fracture line to the ideal starting point. A precise understanding of this anatomy is critical when treating proximal pole scaphoid fractures surgically.

scholarly journals Diagnostic accuracy of history taking, physical examination and imaging for phalangeal, metacarpal and carpal fractures: a systematic review update

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Patrick Krastman ◽  
Nina M. Mathijssen ◽  
Sita M. A. Bierma-Zeinstra ◽  
Gerald Kraan ◽  
Jos Runhaar
Keyword(s):  
Physical Examination ◽  
Diagnostic Accuracy ◽  
Predictive Value ◽  
Scaphoid Fracture ◽  
Radiological Examination ◽  
Supporting Evidence ◽  
History Taking ◽  
Wrist Fractures ◽  
Scaphoid Fractures ◽  
Work Up

Abstract Background The standard diagnostic work-up for hand and wrist fractures consists of history taking, physical examination and imaging if needed, but the supporting evidence for this work-up is limited. The purpose of this study was to systematically examine the diagnostic accuracy of tests for hand and wrist fractures. Methods A systematic search for relevant studies was performed. Methodological quality was assessed and sensitivity (Se), specificity (Sp), accuracy, positive predictive value (PPV) and negative predictive value (NPV) were extracted from the eligible studies. Results Of the 35 eligible studies, two described the diagnostic accuracy of history taking for hand and wrist fractures. Physical examination with or without radiological examination for diagnosing scaphoid fractures (five studies) showed Se, Sp, accuracy, PPV and NPV ranging from 15 to 100%, 13–98%, 55–73%, 14–73% and 75–100%, respectively. Physical examination with radiological examination for diagnosing other carpal bone fractures (one study) showed a Se of 100%, with the exception of the triquetrum (75%). Physical examination for diagnosing phalangeal and metacarpal fractures (one study) showed Se, Sp, accuracy, PPV and NPV ranging from 26 to 55%, 13–89%, 45–76%, 41–77% and 63–75%, respectively. Imaging modalities of scaphoid fractures showed predominantly low values for PPV and the highest values for Sp and NPV (24 studies). Magnetic Resonance Imaging (MRI), Computed Tomography (CT), Ultrasonography (US) and Bone Scintigraphy (BS) were comparable in diagnostic accuracy for diagnosing a scaphoid fracture, with an accuracy ranging from 85 to 100%, 79–100%, 49–100% and 86–97%, respectively. Imaging for metacarpal and finger fractures showed Se, Sp, accuracy, PPV and NPV ranging from 73 to 100%, 78–100%, 70–100%, 79–100% and 70–100%, respectively. Conclusions Only two studies were found on the diagnostic accuracy of history taking for hand and wrist fractures in the current review. Physical examination was of moderate use for diagnosing a scaphoid fracture and of limited use for diagnosing phalangeal, metacarpal and remaining carpal fractures. MRI, CT and BS were found to be moderately accurate for the definitive diagnosis of clinically suspected carpal fractures.

scholarly journals Comparing Biomechanical Properties, Repair Times, and Value of Common Core Flexor Tendon Repairs

Hand ◽  
2017 ◽  
Vol 13 (3) ◽  
pp. 313-318 ◽  
Author(s):  
Aakash Chauhan ◽  
Patrick Schimoler ◽  
Mark C. Miller ◽  
Alexander Kharlamov ◽  
Gregory A. Merrell ◽  
...  
Keyword(s):  
Flexor Tendon ◽  
Maximum Load ◽  
Biomechanical Properties ◽  
Barbed Suture ◽  
Load To Failure ◽  
Fresh Frozen ◽  
Post Hoc ◽  
Biomechanical Strength ◽  
Determining Factor

Background: The aim of the study was to compare biomechanical strength, repair times, and repair values for zone II core flexor tendon repairs. Methods: A total of 75 fresh-frozen human cadaveric flexor tendons were harvested from the index through small finger and randomized into one of 5 repair groups: 4-stranded cross-stitch cruciate (4-0 polyester and 4-0 braided suture), 4-stranded double Pennington (2-0 knotless barbed suture), 4-stranded Pennington (4-0 double-stranded braided suture), and 6-stranded modified Lim-Tsai (4-0 looped braided suture). Repairs were measured in situ and their repair times were measured. Tendons were linearly loaded to failure and multiple biomechanical values were measured. The repair value was calculated based on operating room costs, repair times, and suture costs. Analysis of variance (ANOVA) and Tukey post hoc statistical analysis were used to compare repair data. Results: The braided cruciate was the strongest repair ( P > .05) but the slowest ( P > .05), and the 4-stranded Pennington using double-stranded suture was the fastest ( P > .05) to perform. The total repair value was the highest for braided cruciate ( P > .05) compared with all other repairs. Barbed suture did not outperform any repairs in any categories. Conclusions: The braided cruciate was the strongest of the tested flexor tendon repairs. The 2-mm gapping and maximum load to failure for this repair approached similar historical strength of other 6- and 8-stranded repairs. In this study, suture cost was negligible in the overall repair cost and should be not a determining factor in choosing a repair.

scholarly journals Biomechanical Strength of Scaphoid Partial Unions

2018 ◽  
Vol 07 (05) ◽  
pp. 399-403 ◽  
Author(s):  
Mark Snoddy ◽  
Donald Lee ◽  
Marc Richard ◽  
Mihir Desai ◽  
Adam Brekke
Keyword(s):  
Failure Mechanism ◽  
Clinical Relevance ◽  
Permanent Deformation ◽  
Maximum Load ◽  
Control Group ◽  
Average Maximum ◽  
Significant Difference ◽  
Load To Failure ◽  
Biomechanical Strength ◽  
Inherent Stability

Background It remains unknown how much force a partially united scaphoid can sustain without refracturing. This is critical in determining when to discontinue immobilization in active individuals. Purpose The purpose of this study was to test the biomechanical strength of simulated partially united scaphoids. We hypothesized that no difference would exist in load-to-failure or failure mechanism in scaphoids with 50% or more bone at the waist versus intact scaphoids. Materials and Methods Forty-one cadaver scaphoids were divided into four groups, three experimental osteotomy groups (25, 50, and 75% of the scaphoid waist) and one control group. Each was subjected to a physiologic cantilever force of 80 to 120 N for 4,000 cycles, followed by load to failure. Permanent deformation during physiologic testing and stiffness, max force, work-to-failure, and failure mechanism during load to failure were recorded. Results All scaphoids survived subfailure conditioning with no significant difference in permanent deformation. Intact scaphoids endured an average maximum load to failure of 334 versus 321, 297, and 342 N for 25, 50, and 75% groups, respectively, with no significant variance. There were no significant differences in stiffness or work to failure between intact, 25, 50, and 75% groups. One specimen from each osteotomy group failed by fracturing through the osteotomy; all others failed near the distal pole loading site. Conclusion All groups behaved similarly under physiologic and load-to-failure testing, suggesting that inherent stability is maintained with at least 25% of the scaphoid waist intact. Clinical Relevance The data provide valuable information regarding partial scaphoid union and supports mobilization once 25% union is achieved.

scholarly journals Biomechanical Analysis of the Efficacy of Locking Plates during Cyclic Loading in Metacarpal Fractures

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Stefanie Doht ◽  
Rainer H. Meffert ◽  
Michael J. Raschke ◽  
Torsten Blunk ◽  
Sabine Ochman
Keyword(s):  
Cyclic Loading ◽  
Locking Plate ◽  
Screw Fixation ◽  
Maximum Load ◽  
Biomechanical Analysis ◽  
Locking Plates ◽  
Functional Rehabilitation ◽  
Metacarpal Bones ◽  
Load To Failure ◽  
Bicortical Screw

Purpose.To analyse the biomechanical characteristics of locking plates under cyclic loading compared to a nonlocking plate in a diaphyseal metacarpal fracture.Methods.Oblique diaphyseal shaft fractures in porcine metacarpal bones were created in a biomechanical fracture model. An anatomical reduction and stabilization with a nonlocking and a comparable locking plate in mono- or bicortical screw fixation followed. Under cyclic loading, the displacement, and in subsequent load-to-failure tests, the maximum load and stiffness were measured.Results.For the monocortical screw fixation of the locking plate, a similar displacement, maximum load, and stiffness could be demonstrated compared to the bicortical screw fixation of the nonlocking plate.Conclusions.Locking plates in monocortical configuration may function as a useful alternative to the currently common treatment with bicortical fixations. Thereby, irritation of the flexor tendons would be avoided without compromising the stability, thus enabling the necessary early functional rehabilitation.

Gadolinium Enhanced Mr Assessment of Proximal Fragment Vascularity in Nonunions after Scaphoid Fracture: Does It Predict the Outcome of Reconstructive Surgery?

2004 ◽  
Vol 29 (5) ◽  
pp. 444-448 ◽  
Author(s):  
A.K. SINGH ◽  
T.R.C. DAVIS ◽  
J.S. DAWSON ◽  
J.A. ONI ◽  
N.D. DOWNING
Keyword(s):  
Internal Fixation ◽  
Reconstructive Surgery ◽  
Scaphoid Fracture ◽  
Proximal Fragment ◽  
Proximal Pole ◽  
Scaphoid Fractures ◽  
Fracture Nonunion ◽  
Fracture Nonunions ◽  
Outcome Of Surgery ◽  
Mr Scanning

This study investigated whether the outcome of bone graft and internal fixation surgery for nonunion of scaphoid fractures could be predicted by gadolinium-enhanced MR assessments of proximal fragment vascularity. Sixteen established scaphoid fracture nonunions underwent gadolinium-enhanced MR scanning before surgical treatment with bone grafting and internal fixation. No relationship was found between MR enhancement and the outcome of surgery. Union was achieved in eight of the 12 nonunions with more than 50% enhancement, and three of the four with less than 50% enhancement, of the proximal pole. Furthermore, union was achieved in both of the nonunions which had less than 25% enhancement of the proximal pole. We conclude that enhanced MR assessments of the vascularity of the proximal fragment of a scaphoid fracture nonunion do not accurately predict the outcome of reconstructive surgery.

scholarly journals Scaphoid Fracture Patterns—Part Two: Reproducibility and Demographics of a Simplified Scaphoid Fracture Classification

2019 ◽  
Vol 08 (06) ◽  
pp. 446-451
Author(s):  
Tessa Drijkoningen ◽  
Amin Mohamadi ◽  
Wouter F. van Leeuwen ◽  
Yonatan Schwarcz ◽  
David Ring ◽  
...  
Keyword(s):  
Electronic Medical Records ◽  
Medical Records ◽  
Interobserver Reliability ◽  
Scaphoid Fracture ◽  
Fracture Classification ◽  
Proximal Pole ◽  
Level Of Evidence ◽  
Related Factors ◽  
Scaphoid Fractures ◽  
Fracture Patterns

Abstract Objective To analyze the reproducibility, reliability, and demographics of a simplified anatomical scaphoid fracture classification based on posteroanterior radiographs using a large database of scaphoid fractures. Methods The study consisted of a retrospective review of electronic medical records of 871 consecutive patients. All patients presented between 2003 and 2014 at two centers. Patient- and surgeon-related factors were analyzed. Additionally, interobserver reliability of the Herbert and simplified scaphoid fracture classifications were tested. Results Proximal pole fractures were defined as fractures in which the center of the fracture line was proximal to the distal scapholunate interval (n = 30), waist fractures (n = 802) were defined as fractures involving the scaphocapitate interval, and distal tubercle fractures (n = 39) were defined as fractures involving the scaphotrapeziotrapezoid (STT) interval. The interobserver reliability of the simplified classification was fair (κ = 0.37) as for the Herbert classification (κ = 0.31). The average doubt of the answers of the observers was 2.1 on a scale from 0 to 10 for the simplified classification and 3.6 for the Herbert classification (P < 0.05). Conclusions All complete fractures across the entire scaphoid distal to the scapholunate articulation and proximal to the STT joint can be classified as waist fractures; nonwaist scaphoid fractures are uncommon (6%) and have somewhat different presentations compared to waist fractures. Simplifying the fracture classification slightly improves interobserver reliability, although remaining fair, and significantly reduces doubt. Level of Evidence This is a Level III, prognostic study.

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