Comparison of failure strength between metallic and absorbable interference screws. Influence of insertion torque, tunnel-bone block gap, bone mineral density, and interference

Am J Sports Med. 1996 May-Jun;24(3):329-34. doi: 10.1177/036354659602400314.

Abstract

Because of the good initial fixation strength of interference screws used in anterior cruciate ligament reconstruction, metal interference screws have become the standard method for fixation of bone-patellar tendon-bone grafts. To avoid some of the complications with metal screws, a bioabsorbable interference screw was developed. Data on fixation strength in older human cadavers indicate a similar failure strength between bioabsorbable and metal screws. We studied the failure mechanisms, insertion torques, and fixation strengths of absorbable and metal interference screws in cadaveric knees from young and middle-aged donors. With identical gap and screw size, the mean insertion torque for the metal screws (mean, 1.5 N-m; SD, 0.8) was significantly higher than for the absorbable screws (mean, 0.3 N-m; SD, 0.19). The mean failure load for the metal screws (mean 640 N; SD, 201) was also significantly higher than for the absorbable screws (mean, 418 N; SD, 118).

Publication types

  • Comparative Study

MeSH terms

  • Absorption
  • Adult
  • Anterior Cruciate Ligament / surgery*
  • Biocompatible Materials* / chemistry
  • Bone Density*
  • Bone Screws*
  • Bone Transplantation
  • Cadaver
  • Equipment Design
  • Equipment Failure
  • Femur / surgery*
  • Humans
  • Metals* / chemistry
  • Middle Aged
  • Patellar Ligament / transplantation
  • Rotation
  • Stress, Mechanical
  • Surface Properties
  • Tensile Strength
  • Tibia

Substances

  • Biocompatible Materials
  • Metals