Original Research

Headless Compression Screw Fixation of Vertical Medial Malleolus Fractures is Superior to Unicortical Screw Fixation

Author and Disclosure Information


  • Optimal fixation of vertical sheer ankle fractures is unknown.
  • Headless compression screws are stiffer than cancellous screws in offset axial load.
  • Headless compression screws have a higher load to failure than cancellous screws.
  • Headless compression screws may offer a soft tissue friendly fixation of method for vertical sheer ankle fractures.
  • These findings may not apply when subject to cyclic loads or in osteoporotic bone.




This study is the first biomechanical research of headless compression screws for fixation of vertical shear fractures of the medial malleolus, a promising alternative that potentially offers several advantages for fixation.

Vertical shear fractures were simulated by osteotomies in 20 synthetic distal tibiae. Models were randomly assigned to fixation with either 2 parallel cancellous screws or 2 parallel Acutrak 2 headless compression screws (Acumed). Specimens were subjected to offset axial loading to simulate supination-adduction loading and tracked using high-resolution video.

The headless compression screw construct was significantly stiffer (P < .0001) (360 ± 131 N/mm) than the partially threaded cancellous screws (180 ± 48 N/mm) and demonstrated a significantly increased (P < .0001) mean load to clinical failure (719 ± 91 N vs 343 ± 83 N). When specimens were displaced to 6 mm and allowed to relax, the headless compression screw constructs demonstrated an elastic recoil and were reduced to the pretesting fragment alignment, whereas the parallel cancellous screw constructs remained displaced.

Along with the headless design that may decrease soft tissue irritation, the increased stiffness and elastic recoil of the headless compression screw construct offers improved fixation of medial malleolus vertical shear fractures over the traditional methods.

Continue to: Headless compressions screws...


Next Article: