Figure 3.
Local overexpression of Ad.TGF-β1 in the knee joint induces severe arthrofibrosis. The knees of nude rats were injected bilaterally with 2.0 × 109 v.p. of Ad.TGF-β1 or Ad.GFP (as a negative control). Groups of three animals were killed at days 5, 10 and 30 and the joints (n = 6 per vector and time point) were analyzed for the effects of transgene expression. Images shown are representative of animals killed at day 30. (a, c) External views of knee joints after removal of the skin. (b, d) Internal views of the joints following dissection. For joints receiving Ad.TGF-β1 there was a visible increase in joint size, and the knees became encased in a dense, scar-like tissue. On dissection, the fibrotic tissue was observed to override the joint space and displace preexisting structures. Arrows indicate the location of the patella.