DISTRIBUTION OF CELLULAR REPOPULATION AND COLLAGEN-SYNTHESIS IN A CANINE ANTERIOR CRUCIATE LIGAMENT AUTOGRAFT

Whether the central core of an anterior cruciate ligament autograft re construction is nutritionally compromised at a time when revasculariza tion is known to be complete has not been determined by methods that d etect matrix synthesis. In a canine model of anterior cruciate ligamen t reconstruction with patellar tendon autograft, the adequacy of the s upply of metabolites for cellular matrix synthesis was determined by a utoradiographic analysis. Total collagen synthesis and cellularity wer e also quantified. Total collagen synthesis was found to be significan tly elevated (p = 0.014 by analysis of variance) in the ligament recon structions as compared with normal anterior cruciate ligaments or pate llar tendons, but cellularity was not (p = 0.13 by analysis of varianc e). Autoradiography demonstrated even distribution of [H-3]proline inc orporation throughout the graft and normal tissue. When revascularizat ion was complete, there was an adequate supply of metabolites for cell ular synthesis of protein macromolecules within all regions of the lig ament reconstruction. At 3 months after reconstruction, the grafts wer e found to be actively remodeling their collagen matrix. Since the lon g-term function of an anterior cruciate ligament autograft is dependen t on viable fibroblasts to maintain the collagen matrix, the canine an terior cruciate ligament reconstruction contains living cells that are able to remodel the matrix under appropriate conditions.