Dataset Information

Rotational Stability of Scaphoid Osteosyntheses: An In Vitro Comparison of Small Fragment Cannulated Screws to Novel Bone Screw Sets.

ABSTRACT:

Background

The current standard of care for operative repair of scaphoid fractures involves reduction and internal fixation with a single headless compression screw. However, a compression screw in isolation does not necessarily control rotational stability at a fracture or nonunion site. The single screw provides rotational control through friction and bone interdigitation from compression at the fracture site. We hypothesize that osteosyntheses with novel bone screw sets (BSS) equipped with anti-rotational elements provide improved rotational stability.

Methods

Stability of osteosynthesis under increasing cyclic torsional loading was investigated on osteotomized cadaveric scaphoids. Two novel prototype BSS, oblique type (BSS-obl.) and longitudinal type (BSS-long.) were compared to three conventional screws: Acutrak2®mini, HCS®3.0 and Twinfix®. Biomechanical tests were performed on scaphoids from single donors in paired comparison and analyzed by balanced incomplete random block design. Loading was increased by 50 mNm increments with 1,000 cycles per torque level and repeated until a rotational clearance of 10°. Primary outcome measure was the number of cycles to 10° clearance, secondary outcome measure was the maximum rotational clearance for each torque level.

Findings

BSS-obl. performed significantly better than Acutrak2®mini and HCS® (p = 0.015, p<0.0001). BSS-long. performed significantly better than HCS® (p = 0.010). No significant difference in performance between BSS-obl. and BSS-long. (p = 0.361), between BSS obl. and Twinfix® (p = 0.50) and BSS long. and Twinfix® (p = 0.667) was detected. Within the torque range up to 200 mNm, four of 21 (19%) BSS-long. and four of 21 (19%) BSS-obl. preparations showed early failure. The same loading led to early failure in four (29%) Twinfix®, seven (50%) Acutrak2®mini and 10 (71%) HCS® of 14 screw samples, respectively.

Conclusions

For both BSS and to a lesser extent for Twinfix® (as dual-component screw), higher rotational stabilities were identified in comparison to single component headless compression screws.

SUBMITTER: Erhart J

PROVIDER: S-EPMC4892476 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

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Publications

Rotational Stability of Scaphoid Osteosyntheses: An In Vitro Comparison of Small Fragment Cannulated Screws to Novel Bone Screw Sets.

Erhart Jochen J Unger Ewald E Schefzig Philip P Varga Peter P Trulson Inga I Gormasz Anna A Trulson Alexander A Reschl Martin M Hagmann Michael M Vecsei Vilmos V Mayr Winfried W

PloS one 20160603 6

<h4>Background</h4>The current standard of care for operative repair of scaphoid fractures involves reduction and internal fixation with a single headless compression screw. However, a compression screw in isolation does not necessarily control rotational stability at a fracture or nonunion site. The single screw provides rotational control through friction and bone interdigitation from compression at the fracture site. We hypothesize that osteosyntheses with novel bone screw sets (BSS) equipped ...[more]

PMID: 27258387

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Dataset Information

Rotational Stability of Scaphoid Osteosyntheses: An In Vitro Comparison of Small Fragment Cannulated Screws to Novel Bone Screw Sets.

Background

Methods

Findings

Conclusions

Publications

Rotational Stability of Scaphoid Osteosyntheses: An In Vitro Comparison of Small Fragment Cannulated Screws to Novel Bone Screw Sets.

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