Clinical utilization of injectable collagen.

The applications for an injectable, highly purified form of calfhide collagen (Zyderm Collagen Implant) were first described by Knapp et al in 1977. Since that time, the material has undergone evaluation in a nationwide clinical trial in which 728 physicians participated under a cooperative protocol. In these trials--which culminated in marketing clearance by the Food and Drug Administration--over 5,000 patients were treated for a variety of soft-tissue depressions resulting from surgery, atrophy, acne, viral pox, and aging. We participated in the clinical trial and have used injectable collagen in our practices since 1977 when the material was undergoing evaluation in California. We have treated over 400 patients with injectable collagen for a variety of facial cutaneous defects. The material has proved to be an effective tool for correction of certain soft-tissue defects not previously amenable to correction, and a useful surgical adjunct. Simplicity and safety are its major advantages. The persistence of correction afforded by injectable collagen is variable, but the majority of our patients have maintained improvement twelve or more months since the end of treatment. Hence we believe that there is a definite role for injectable collagen but that its long-term persistence must still be confirmed. This paper represents our state-of-the-art assessment of injectable collagen after six years of personal experience.