We used the hydrogen wash-out technique to determine the rate of
wash-out of an inert tracer from the posterior cruciate ligament in dogs
and rabbits after we had detached the ligament from bone and synovial
structures, and after we had isolated it from the synovial tissue with
aluminum foil. These rates were compared with those from controls and no
differences could be found between them. The uptake of tritiated proline
administered intravenously was also shown not to be significantly different
in the detached ligament as compared with an intact ligament. Isolation of
the ligament from contact with the synovial lining prevented the uptake of
hydrogen. Cruciate ligaments removed from the knee and placed in the
suprapatellar pouch appeared viable after eight to ten days. These findings
suggest that diffusion can serve as a major pathway for delivery of
nutrients to the cruciate ligaments.