Mechanical Tensile Properties of the Quadriceps Tendon and Patellar Ligament in Young Adults

Abstract

We analyzed mechanical tensile properties of 16 10-mm wide, full-thickness central parts of quadriceps tendons and patellar ligaments from paired knees of eight male donors (mean age, 24.9 years). Uniaxial tensile testing was performed in a servohydraulic materials testing machine at an extension rate of 1 mm/ sec. Sixteen specimens were tested unconditioned and 16 specimens were tested after cyclic preconditioning (200 cycles between 50 N and 800 N at 0.5 Hz). Mean cross-sectional areas measured 64.6 8.4 mm2 for seven unconditioned and 61.9 9.0 mm 2 for eight preconditioned quadriceps tendons and were significantly larger than those values of seven unconditioned and seven preconditioned patellar ligaments (36.8 5.7 mm2 and 34.5 4.4 mm2, respectively). Mean ultimate tensile stress values of unconditioned patellar ligaments were significantly larger than those values of unconditioned quadriceps tendons: 53.4 7.2 N/mm2 and 33.6 8.1 N/mm2, respectively. Strain at failure was 14.4% 3.3% for preconditioned patellar ligaments and 11.2% 2.2% for preconditioned quadriceps tendons (P 0.0428). Preconditioned patellar ligaments exhibited significantly higher elastic modulus than preconditioned quadriceps tendons. Based on mechanical tensile properties analyses, the quadriceps tendon-bone construct may represent a versatile alternative graft in primary and revision anterior and posterior cruciate ligament reconstruction.