TY - JOUR

T1 - Corticosteroid administration alters the mechanical properties of isolated collagen fascicles in rat-tail tendon

AU - Haraldsson, B T

AU - Aagaard, P

AU - Crafoord-Larsen, D

AU - Kjaer, M

AU - Magnusson, S P

N1 - Keywords: Animals; Anti-Inflammatory Agents; Biomechanics; Collagen; Male; Methylprednisolone; Rats; Rats, Wistar; Tail; Tendons; Tensile Strength

PY - 2009

Y1 - 2009

N2 - Overload tendon injuries are frequent in recreational and elite sports. The optimal treatment strategy remains unknown, but local administration of corticosteroids is one common treatment option. The direct effects of the corticosteroid administration on the tissue are not fully understood. The present study examined the biomechanical effects of intratendinous corticosteroid injections on healthy rat-tail tendon collagen fascicles. A total of 24 Wistar male rats were divided into (A) a corticosteroid group where the animals were injected in the tail tendon with methylprednisolone acetate, 1.0 mL of 40 mg/mL mixed with 1.0 mL 9% saline (n=12), and (B) a control group that was injected with 9% saline (n=12). Three days after the injections, the animals were sacrificed and single individual collagen fascicles were collected and underwent displacement to failure. Corticosteroid administration significantly reduced tensile fascicle yield strength by 16% and Young's modulus by 14% compared with sham treatment (10.5+/-0.8 vs 12.4+/-0.5 MPa, P< or =0.05, and 537+/-27 vs 641+/-30 MPa, P<0.05, respectively), while the strain properties were unaffected. Peak stress was similar between the two groups. There was no difference in fascicle diameter between the two groups.

AB - Overload tendon injuries are frequent in recreational and elite sports. The optimal treatment strategy remains unknown, but local administration of corticosteroids is one common treatment option. The direct effects of the corticosteroid administration on the tissue are not fully understood. The present study examined the biomechanical effects of intratendinous corticosteroid injections on healthy rat-tail tendon collagen fascicles. A total of 24 Wistar male rats were divided into (A) a corticosteroid group where the animals were injected in the tail tendon with methylprednisolone acetate, 1.0 mL of 40 mg/mL mixed with 1.0 mL 9% saline (n=12), and (B) a control group that was injected with 9% saline (n=12). Three days after the injections, the animals were sacrificed and single individual collagen fascicles were collected and underwent displacement to failure. Corticosteroid administration significantly reduced tensile fascicle yield strength by 16% and Young's modulus by 14% compared with sham treatment (10.5+/-0.8 vs 12.4+/-0.5 MPa, P< or =0.05, and 537+/-27 vs 641+/-30 MPa, P<0.05, respectively), while the strain properties were unaffected. Peak stress was similar between the two groups. There was no difference in fascicle diameter between the two groups.

U2 - 10.1111/j.1600-0838.2008.00859.x

DO - 10.1111/j.1600-0838.2008.00859.x

M3 - Journal article

C2 - 18980605

VL - 19

SP - 621

EP - 626

JO - Scandinavian Journal of Medicine & Science in Sports

JF - Scandinavian Journal of Medicine & Science in Sports

SN - 0905-7188

IS - 5

ER -