Freeze-dried allografts for anterior cruciate ligament reconstruction.

Freeze-dried allografts represent a viable and functional alternative to fresh-frozen allograft and autograft constructs. Compared with fresh-frozen allograft constructs, freeze-dried soft tissue allograft constructs have many advantages including limited immunogenicity, ease of graft storage, comparable mechanical properties of soft tissue constructs, and the potential for improved biologic incorporation. This article reviews the fundamental processing of freeze-dried allografts and summarizes the clinical and basic science studies supporting the safe and effective use of freeze-dried allograft constructs for anterior cruciate ligament reconstruction. It also discusses potential directions of future research on tissue-engineered anterior cruciate ligament constructs using freeze-dried tendon constructs.