1. Harvard/MIT Division of Health Sciences and Technology, Cambridge, Massachusetts 02139.
2. Department of Orthopedic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115.
3. Genzyme Tissue Repair, Framingham, Massachusetts 01701.
4. Department of Orthopedic Surgery, University of Vienna, Austria A-1090.
5. Rehabilitation Engineering R&D Laboratory, Brockton/West Roxbury VA Medical Center, West Roxbury, Massachusetts 02132.