Patellar tendon length after anterior cruciate ligament reconstruction.A prospective study

Shortening of the patellar tendon after anterior cruciate ligament (ACL) reconstruction has been implicated as a cause of postoperative complications such as anterior knee pain, patella infera syndrome, and traumatic patellar tendon rupture. This prospective study was designed to asses whether closure of the patellar tendon defect during ACL reconstruction with mid-third bone-patellar tendon-bone autograft leads to radiographic evidence of patellar tendon shortening. One hundred fourteen patients underwent arthroscopically assisted ACL reconstruction using mid-third bone-patellar tendon-bone autograft. Group I (59 patients) had the patellar tendon defect left open. Group II (55 patients) had the defect sutured closed. The paratenon was approximated in all patients. Lateral knee radiographs were taken pre- and post-operatively. The pre- and postoperative patellar tendon lengths were measured and compared. Group I (defect left open) showed virtually no patellar tendon shortening (average 0.3%). Group II (defect closed) showed minimal but slightly more shortening (average: 0.51%). The maximum shortening was 2.3% in Group I and 4.3% in Group II. Therefore, closure of the patellar tendon defect does not significantly alter the length of the patellar tendon after ACL reconstruction.