Does the patellar tendon normalize after harvesting its central third?: a prospective long-term MRI study.

Abstract

The central third of the patellar tendon is the most frequently used autograft for ACL reconstruction. The patellar tendon at the donor site would look normal as seen on MRI 6 years after harvesting its central third. Nineteen consecutive patients were included in the study. MRI examinations of the donor site were performed at 6 (5 to 10) weeks, 6 (6 to 8) months, 27 (24 to 29) months, and 71 (68 to 73) months postoperatively. The contralateral normal side was examined only on the first occasion. The size of the donor-site gap decreased significantly (P = 0.0001) between 6 weeks and 6 years. In most patients, a thinning of the central part of the patellar tendon was still found at 6 years. The thickness of the peripheral patellar tendon was increased, compared with the contralateral healthy side, until 2 years (P = 0.003). On all occasions, the width was increased compared with the contralateral side (P < 0.015). Prospective MRI examinations revealed that the patellar tendon at the donor site had not normalized 6 years after harvesting its central third. The reharvesting of the patellar tendon can therefore not be recommended.