How to ease the fixation of carpal bones? Twenty-four lesions treated by 1,5 mm headless compression screws

Background: Management of scaphoid nonunions with bone loss varies substantially. Commonly, internal fixation consists of a single headless compression screw. Recently, some authors have reported on the theoretical benefits of dual-screw fixation. We hypothesized that using 2 headless compression screws would impart improved stiffness over a single-screw construct. Methods: Using a cadaveric model, we compared biomechanical characteristics of a single tapered 3.5- to 3.6-mm headless compression screw with 2 tapered 2.5- to 2.8-mm headless compression screws in a scaphoid waist nonunion model. The primary outcome measurement was construct stiffness. Secondary outcome measurements included load at 1 and 2 mm of displacement, load to failure for each specimen, and qualitative assessment of mode of failure. Results: Stiffness during load to failure was not significantly different between single- and double-screw configurations ( P = .8). Load to failure demonstrated no statistically significant difference between single- and double-screw configurations. Using a qualitative assessment, the double-screw construct maintained rotational stability more than the single-screw construct ( P = .029). Conclusions: Single- and double-screw fixation constructs in a cadaveric scaphoid nonunion model demonstrate similar construct stiffness, load to failure, and load to 1- and 2-mm displacement. Modes of failure may differ between constructs and represent an area for further study. The theoretical benefit of dual-screw fixation should be weighed against the morphologic limitations to placing 2 screws in a scaphoid nonunion.

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Metacarpal Bony Dimensions Related to Headless Compression Screw Sizes

Journal of Hand and Microsurgery ◽

10.1055/s-0039-3400443 ◽

2019 ◽

Vol 12 (S 01) ◽

pp. S39-S44

Author(s):

Michael Okoli ◽

Kevin Lutsky ◽

Michael Rivlin ◽

Brian Katt ◽

Pedro Beredjiklian

Keyword(s):

Computed Tomography ◽

Fracture Fixation ◽

Ct Scans ◽

Compression Screw ◽

Metacarpal Head ◽

Headless Compression Screw ◽

Metacarpal Bones ◽

Headless Compression Screws ◽

The Mean ◽

Distal Aspect

Abstract Introduction The purpose of this study is to determine the radiographic dimensions of the finger metacarpals and to compare these measurements with headless compression screws commonly used for fracture fixation. Materials and Methods We analyzed computed tomography (CT) scans of the index, long, ring, and small metacarpal bones and measured the metacarpal length, distance from the isthmus to the metacarpal head, and intramedullary diameter of the isthmus. Metacarpals with previous fractures or hardware were excluded. We compared these dimensions with the size of several commercially available headless screws used for intramedullary fixation. Results A total of 223 metacarpals from 57 patients were analyzed. The index metacarpal was the longest, averaging 67.6 mm in length. The mean distance from the most distal aspect of the metacarpal head to the isthmus was 40.3, 39.5, 34.4, and 31 mm for the index, long, ring, and small metacarpals, respectively. The narrowest diameter of the isthmus was a mean of 2.6, 2.7, 2.3, and 3 mm for the index, long, ring, and small metacarpals, respectively. Of 33 commercially available screws, only 27% percent reached the isthmus of the index metacarpal followed by 42, 48, and 58% in the long, ring, and small metacarpals, respectively. Conclusion The index and long metacarpals are at a particular risk of screw mismatch given their relatively long lengths and narrow isthmus diameters.

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Biomechanical stability of complex coronal plane fracture fixation of the capitellum

Archives of Orthopaedic and Trauma Surgery ◽

10.1007/s00402-021-04126-1 ◽

2021 ◽

Author(s):

Paul Borbas ◽

Rafael Loucas ◽

Marios Loucas ◽

Maximilian Vetter ◽

Simon Hofstede ◽

...

Keyword(s):

Fracture Fixation ◽

Ultimate Load ◽

Locking Plate ◽

Distal Humerus ◽

Coronal Plane ◽

Fixation Strength ◽

Biomechanical Stability ◽

Significant Difference ◽

Load To Failure ◽

Headless Compression Screws

Abstract Introduction Coronal plane fractures of the distal humerus are relatively rare and can be challenging to treat due to their complexity and intra-articular nature. There is no gold standard for surgical management of these complex fractures. The purpose of this study was to compare the biomechanical stability and strength of two different internal fixation techniques for complex coronal plane fractures of the capitellum with posterior comminution. Materials and methods Fourteen fresh frozen, age- and gender-matched cadaveric elbows were 3D-navigated osteotomized simulating a Dubberley type IIB fracture. Specimens were randomized into one of two treatment groups and stabilized with an anterior antiglide plate with additional anteroposterior cannulated headless compression screws (group antiGP + HCS) or a posterolateral distal humerus locking plate with lateral extension (group PLP). Cyclic testing was performed with 75 N over 2000 cycles and ultimately until construct failure. Data were analyzed for displacement, construct stiffness, and ultimate load to failure. Results There was no significant difference in displacement during 2000 cycles (p = 0.291), stiffness (310 vs. 347 N/mm; p = 0.612) or ultimate load to failure (649 ± 351 vs. 887 ± 187 N; p = 0.140) between the two groups. Conclusions Posterolateral distal humerus locking plate achieves equal biomechanical fixation strength as an anterior antiglide plate with additional anteroposterior cannulated headless compression screws for fracture fixation of complex coronal plane fractures of the capitellum. These results support the use of a posterolateral distal humerus locking plate considering the clinical advantages of less invasive surgery and extraarticular metalware. Level of evidence Biomechanical study.

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Four-corner fusion: Clinical and radiological outcome after fixation by headless compression screws or dorsal locking plate at minimum 5 years’ follow-up

Orthopaedics & Traumatology Surgery & Research ◽

10.1016/j.otsr.2021.102886 ◽

2021 ◽

pp. 102886

Author(s):

Marc-Antoine d’Almeida ◽

Nadine Sturbois-Nachef ◽

Thomas Amouyel ◽

Christophe Chantelot ◽

Marc Saab

Keyword(s):

Locking Plate ◽

Radiological Outcome ◽

Headless Compression Screws ◽

Clinical And Radiological Outcome

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Metacarpal shaft fixation: a biomechanical comparison of dorsal plating, lag screws, and headless compression screws

BMC Musculoskeletal Disorders ◽

10.1186/s12891-021-04200-0 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Felix G. E. Dyrna ◽

Daniel M. Avery ◽

Ryu Yoshida ◽

David Lam ◽

Simon Oeckenpöhler ◽

...

Keyword(s):

Peak Load ◽

Rigid Fixation ◽

Advantages And Disadvantages ◽

Shaft Fractures ◽

Metacarpal Shaft ◽

Significant Difference ◽

Load To Failure ◽

Headless Compression Screws ◽

Diaphyseal Fractures ◽

Dorsal Plating

Abstract Background Metacarpal shaft fractures are common and can be treated nonoperatively. Shortening, angulation, and rotational deformity are indications for surgical treatment. Various forms of treatment with advantages and disadvantages have been documented. The purpose of the study was to determine the stability of fracture fixation with intramedullary headless compression screws in two types of metacarpal shaft fractures and compare them to other common forms of rigid fixation: dorsal plating and lag screw fixation. It was hypothesized that headless compression screws would demonstrate a biomechanical stronger construct. Methods Five matched paired hands (age 60.9 ± 4.6 years), utilizing non-thumb metacarpals, were used for comparative fixation in two fracture types created by an osteotomy. In transverse diaphyseal fractures, fixation by headless compression screws (n = 7) and plating (n = 8) were compared. In long oblique diaphyseal fractures, headless compression screws (n = 8) were compared with plating (n = 8) and lag screws (n = 7). Testing was performed using an MTS frame producing an apex dorsal, three point bending force. Peak load to failure and stiffness were calculated from the load-displacement curve generated. Results For transverse fractures, headless compression screws had a significantly higher stiffness and peak load to failure, means 249.4 N/mm and 584.8 N, than plates, means 129.02 N/mm and 303.9 N (both p < 0.001). For long oblique fractures, stiffness and peak load to failure for headless compression screws were means 209 N/mm and 758.4 N, for plates 258.7 N/mm and 518.5 N, and for lag screws 172.18 N/mm and 234.11 N. There was significance in peak load to failure for headless compression screws vs plates (p = 0.023), headless compression screws vs lag screws (p < 0.001), and plates vs lag screws (p = 0.009). There was no significant difference in stiffness between groups. Conclusion Intramedullary fixation of diaphyseal metacarpal fractures with a headless compression screw provides excellent biomechanical stability. Coupled with lower risks for adverse effects, headless compression screws may be a preferable option for those requiring rapid return to sport or work. Level of evidence Basic Science Study, Biomechanics.

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