The connective-tissue envelope in revascularisation of patellar tendon grafts

Free patellar tendon grafts used for the intra-articular replacement of rup tured anterior cruciate ligaments (ACL) lack perfusion at the time of impla ntation. The central core of the graft undergoes a process of ischaemic nec rosis which may result in failure. Early reperfusion of the graft may dimin ish the extent of this process. We assessed the role of peritendinous connective tissue in the revascularis ation of the patellar tendon graft from the day of implantation up to 24 da ys in a murine model using intravital microscopy, The peritendinous connect ive-tissue envelope of the graft was either completely removed, partially r emoved or not stripped before implantation into dorsal skinfold chambers of recipient mice. Initial revascularisation of the grafts with preserved peritendinous connec tive tissues began after two days. The process was delayed by five to six t imes in completely stripped patellar tendons (p < 0.05). Only grafts with p reserved connective tissues showed high viability whereas those which were completely stripped appeared to be subvital, The presence of peritendinous connective tissues accelerates the revascular isation of free patellar tendon grafts.