The biomechanical response to doses of TGF-beta 2 in the healing rabbit medial collateral ligament.
Ligament injuries result in significant disability in over 100,000 patients each year. Despite current methods of treatment, 13% of patients with medial collateral ligament (MCL) injury develop early signs of arthritis, suggesting an incomplete return of knee stability. The principal hypothesis of this work was that the addition of TGF-beta 2 to the healing MCL would accelerate the development of scar strength and stiffness. Forty-four rabbits were divided evenly into four groups, with each group receiving either 0.1, 1 or 5 microg of TGF-beta 2 and the fourth group receiving 1 microg TGF-beta 2 and 1 microg of PDGF. Each rabbit underwent bilateral transection of the MCL, with one side having treatment with one of four doses of growth factor and the other side left untreated. All animals were sacrificed at 6 weeks and the structural properties of maximum load at failure, stiffness, and energy absorbed at failure measured. All treatment groups demonstrated an increase in scar mass, but no group had a significant increase in scar load at failure at 6 weeks. The addition of 0.1 microg TGF-beta 2 led to a significant increase in scar stiffness. The addition of PDGF had no significant effect on any of the parameters studied. This study suggests the mechanical stiffness, but not the load at failure, of ligament scar can be significantly altered by the administration of TGF-beta 2.
Spindler
Kurt P
KP
Department of Orthopaedics and Rehabilitation, Vanderbilt University Medical Center, 2601 Jess Neely Drive, Nashville, TN 37212, USA. kurt.spindler@mcmail.vanderbilt.edu
Murray
Martha M
MM
Detwiler
Kenneth B
KB
Tarter
Jeremy T
JT
Dawson
John M
JM
Nanney
Lillian B
LB
Davidson
Jeffrey M
JM
D000818:Animals; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004548:Elasticity / Q000187:drug effects; D006801:Humans; D017888:Medial Collateral Ligament, Knee / Q000187:drug effects* / Q000293:injuries / Q000503:physiopathology; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D011817:Rabbits; D011994:Recombinant Proteins; D013314:Stress, Mechanical; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053781:Transforming Growth Factor beta2; D014945:Wound Healing / Q000187:drug effects
D010982:Platelet-Derived Growth Factor; D011994:Recombinant Proteins; C509041:TGFB2 protein, human; D016212:Transforming Growth Factor beta; D053781:Transforming Growth Factor beta2