Magnetic resonance imaging evaluation of the patellar tendon after use of its central one-third for anterior cruciate ligament reconstruction.

Magnetic resonance imaging was used to evaluate the remaining patellar tendon after its central one-third had been harvested for anterior cruciate ligament reconstruction. Twenty patients were studied at either 6 weeks, 4, 6, 9, or 18 months postoperatively. The average thickness, width, cross-sectional area, and signal intensity of the operated and contralateral non-operated tendons were calculated and compared for each magnetic resonance imaging scan. A significant increase in the thickness was noted at all periods of followup, but no change in width occurred despite the defect being closed at the time of surgery. High signal intensity was present in the early periods, which signified edema and scar tissue. Signal intensity decreased at subsequent follow-up periods until at 18 months the operated tendon appeared normal. These findings indicate that the patellar tendon has the potential to regenerate and remodel in the postoperative period.