Components of laxity in interference fit fixation of quadrupled hamstring grafts

Acta Orthop Scand. 2002 Jan;73(1):65-71. doi: 10.1080/000164702317281431.


We tested in vitro 15 Poly-L-lactic acid and 14 titanium interference screws in male human cadaver tibia-hamstring constructs. Elongation of the graft, displacement of the screw in the tibial tunnel, and slippage at the graft/screw interface were measured as outcomes with an infrared optical system. All constructs failed by slippage of the graft past the interference screw. On average, graft slippage accounted for 92% of total construct laxity at 5mm total construct elongation, whereas permanent stretching of the midsubstance of the graft accounted for only 8%. Movement of the interference screw in the tibial canal was minimal, averaging 0.01 (0-0.5) mm at construct failure. Inadequacy of isolated tibial interference screw fixation of soft tissue grafts may be overcome if early failure at the graft/screw interface is prevented.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Anterior Cruciate Ligament / surgery*
  • Biomechanical Phenomena
  • Cadaver
  • Confidence Intervals
  • Graft Survival
  • Humans
  • Male
  • Middle Aged
  • Muscle, Skeletal / surgery
  • Polyesters
  • Probability
  • Sensitivity and Specificity
  • Stress, Mechanical
  • Tensile Strength
  • Tissue Transplantation / methods*
  • Titanium


  • Polyesters
  • poly(lactide)
  • Titanium