A radiographic and histologic evaluation of the patellar tendon after harvesting its central third

Nineteen consecutive patients undergoing anterior cruciate ligament reconst ruction using the central third of the ipsilateral patellar tendon were inc luded in the study. Serial magnetic resonance images revealed that the dono r-site gap in the tendon decreased with time (mean follow-up, 26 months). T he thickness was significantly increased compared with the intact contralat eral patellar tendon, regardless of when the magnetic resonance imaging was performed. Ultrasonography showed the same findings at a mean follow-up of 26 months. Histologic evaluation of the repair tissue in the central part of the tendon, as well as the tissue in the peripheral part of the patellar tendon at the donor site, revealed a significant increase in cellularity a nd vascularity as compared with normal control tendons. Thus, 2 years after the harvesting procedure, the patellar tendon displayed significant radiog raphic and histologic abnormalities. On the basis of these findings, reharv est of the patellar tendon, at least up to 2 years after primary harvest, c annot be recommended.