Although numerous procedures have been described for the reconstruction
of the anterior and posterior cruciate ligaments, there has been little
evaluation of the viability and strength of these substitutes. Using
microangiographic, histological, and biomechanical techniques, we studied
the vascularity and tensile strength of the medial one-third of the
patellar tendon at intervals after it had been inserted as a substitute for
either the anterior or the posterior cruciate ligament in twenty-nine young
adult Rhesus monkeys. For the anterior cruciate reconstruction (nineteen
knees), we used and medial one-third of the patellar tendon elongated by a
portion of the patella. For the posterior cruciate reconstruction (ten
knees), we used the medial one-third of the patellar tendon lengthened by
attached portions of the patella and tibia as a free graft. Both the
anterior and the posterior cruciate ligament substitutes were
revascularized at eight weeks, and at one year they had approximately 80
per cent of the tensile strength that they had prior to transfer.