Mechanical tensile properties of the quadriceps tendon and patellar ligament in young adults

We analyzed mechanical tensile properties of 16 10-mm wide, full-thickness central parts of quadriceps tendons and patellar ligaments from paired knee s of eight male donors (mean age, 24.9 years). Uniaxial tensile testing was performed in a servohydraulic materials testing machine at an extension ra te of 1 mm/sec. Sixteen specimens were tested unconditioned and 16 specimen s 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 mm(2) for s even unconditioned and 61.9 +/- 9.0 mm(2) for eight preconditioned quadrice ps tendons and were significantly larger than those values of seven uncondi tioned and seven preconditioned patellar ligaments (36.8 +/- 5.7 mm(2) and 34.5 +/- 4.4 mm(2), respectively). Mean ultimate tensile stress values of u nconditioned patellar ligaments were significantly larger than those values of unconditioned quadriceps tendons: 53.4 +/- 7.2 N/mm(2) and 33.6 +/- 8.1 N/mm(2), respectively. Strain at failure was 14.4% +/- 3.3% for preconditi oned patellar ligaments and 11.2% +/- 2.2% for preconditioned quadriceps te ndons (P = 0.0428). Preconditioned patellar ligaments exhibited significant ly higher elastic modulus than preconditioned quadriceps tendons. Based on mechanical tensile properties analyses, the quadriceps tendon-bone construc t may represent a versatile alternative graft in primary and revision anter ior and posterior cruciate ligament reconstruction.