Does a trochanteric lag screw improve fixation of vertically oriented femoral neck fractures? A biomechanical analysis in cadaveric bone

Hawks, Michael A.; Kim, Hyunchul; Strauss, Joseph E.; Oliphant, Bryant W.; Golden, Robert D.; Hsieh, Adam H.; Nascone, Jason W.; O’Toole, Robert V.

doi:10.1016/j.clinbiomech.2013.08.007

Cited by 41 publications

(32 citation statements)

References 9 publications

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“…26 Compared with three parallel cancellous screws, PCS significantly improved the mechanical properties of vertical femoral neck fractures, and the improvements seemed to be consistent with the performance of dynamic hip screws. 12 The models developed in this study fully support the improved biomechanical stability of the new plate fixation technique.…”

Section: Discussionmentioning

confidence: 58%

Finite element analysis of a new plate for Pauwels type III femoral neck fractures

Wang

Tang²,

et al. 2020

J Int Med Res

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Background: A new plate for the treatment of Pauwels type III femoral neck fractures was developed, and its biomechanical stability was analyzed by the finite element method. Method: Using 3-matic and UG-NX software, we constructed models of Pauwels type III femoral neck fractures with angles of 50 , 60 , and 70 . Moreover, a new femoral neck plate (NFNP) fixation model and a Pauwels screw fixation model were developed. Under axial loads of 1400 N and 2100 N, von Mises stress (VMS) distribution on the screws, peak VMS, displacement between fracture fragments, and model principal strains in cancellous bone were recorded. Result: The peak VMS of internal fixation in the two models was mostly located near the fracture line, and the screw closest to the femoral calcar experienced maximum stress. With a Pauwels angle of 50 , 60 , and 70 , the peak VMS values of the new plates were lower than in the Pauwels screw. The displacement of fracture fragments in the NFNP was smaller than in the Pauwels screw, and peak VMS values of cancellous bone in the NFNP were lower than in the Pauwels screw. Conclusion: The newly developed plate provided excellent biomechanical stability for Pauwels type III femoral neck fractures.

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Section: Discussionmentioning

confidence: 58%

Finite element analysis of a new plate for Pauwels type III femoral neck fractures

Wang

Tang²,

et al. 2020

J Int Med Res

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show abstract

“…However, the stiffness of the construct can be modulated by using a Pauwel screw configuration or strategically placed fully threaded screws. In a biomechanical study, Pauwel screws, which include a trochanteric lag screw followed by screws placed parallel to the femoral neck, were 70% stiffer than parallel screws [14]. However, in a retrospective review, 23% of patients treated with parallel screws developed nonunion or avascular necrosis compared to 59% of those treated with crossed/Pauwel screws [15].…”

Section: Biomechanical Studiesmentioning

confidence: 97%

Fixed angle devices versus multiple cancellous screws: What does the evidence tell us?

Hoshino

O’Toole

2015

Injury

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“…The results clearly showed that the triangle configuration withstood higher levels of peak and ultimate loads, higher energy absorption, and less displacement compared with the other screw configurations. Hawks et al assessed the biomechanics of a lag screw construct perpendicular to the fracture combined with two parallel cannulated screws [42]. The study suggested that using this construct to fix a vertically oriented femoral neck fracture provided substantial improvement in mechanical performance compared with the traditional inverted triangle construct.…”

Section: Main Textmentioning

confidence: 99%

“…The author suggested that the optimal fixation for the Pauwels type II or III femoral neck fracture among young adults was DHS combined with an anti-rotation screw. In another clinical study, Virkus et al reviewed the results of 28 vertical femoral neck fractures treated with a horizontal construct combined with two parallel cannulated screws [42]. The results presented a healing rate of 86% and suggested the use of the trochanteric lag screw construct for vertical femoral neck fractures.…”

Section: Main Textmentioning

confidence: 99%

An update on the Pauwels classification

et al. 2016

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BackgroundFemoral neck fractures typically occur as a result of high-energy mechanisms among non-geriatric patients. Complications, including femoral neck shortening, non-union, and avascular necrosis, are relatively common after the internal fixation of this fracture pattern. These complications have serious effects on young patients. The Pauwels classification, which is the first biomechanical classification for femoral neck fractures, is still frequently used to determine and prescribe the appropriate treatment for femoral neck fractures. However, we lack a unified standard for measuring the Pauwels angle, which may make the classification unreliable. Understanding the relationship between the Pauwels classification and the complications arising from the internal fixation of femoral neck fractures is necessary. Meanwhile, a Pauwels type III femoral neck fracture among young adults, which involves a high shear load at the fracture site, is difficult to treat successfully. In addition, the recognized internal fixation for this fracture pattern remains uncertain.Main bodyThis review aims to provide an update on the viewpoint on the Pauwels classification including the measurement of the Pauwels angle and to present evidence to prove the aforementioned relationship. Moreover, this article also discusses the optimal internal fixation for femoral neck fractures based on the Pauwels classification.ConclusionA unified standard of measurement should be established for the Pauwels classification, which is still frequently used in the literature and in determining appropriate treatment for femoral neck fractures, to achieve a credible classification. In addition, more randomized, multicentric, and prospective trials should be conducted in the future to clearly understand the relationship between the Pauwels classification and complications arising from the internal fixation of femoral neck fractures and, consequently, to explore ideal fixations for a Pauwels type III femoral neck fracture.

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Does a trochanteric lag screw improve fixation of vertically oriented femoral neck fractures? A biomechanical analysis in cadaveric bone

Cited by 41 publications

References 9 publications

Finite element analysis of a new plate for Pauwels type III femoral neck fractures

Finite element analysis of a new plate for Pauwels type III femoral neck fractures

Fixed angle devices versus multiple cancellous screws: What does the evidence tell us?

An update on the Pauwels classification

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