Evolution of the patellar tendon size after Bone-Patelar tendon-Bone ACL reconstruction

Introduction

Bone-patellar tendon-bone (BPTB) autograft is the main treatment choice on complete anterior cruciate ligament (ACL) ruptures. However, high donor-site morbidity has been related to this procedure. A better understanding of the donor-site healing process could help us to decrease donor-site problems. The aim of this study is to describe the evolution of the patellar tendon size during the first year after BPTB procedure.

Materials and methods

42 consecutive patients underwent ACL reconstruction using BPTB technique in our facilities. We measured the tendon length, width and thickness through musculoskeletal ultrasound before and at 1, 2, 4, 6, 9 and 12 months after the operation. Tendon measurements from the contralateral unaffected tendon were used as a control group. We compared the values between injured and uninjured legs and between pre-op and post-op values.

Results

Tendon length decreased significantly in both legs, without any difference between legs at 12 months post-op. Tendon width and thickness of the unaffected limbs showed a tendency to stabilization, while the injured limb showed a significant increase in both values during the first 1-2 months. At 12-months post-op, patellar tendon of the injured limb was significantly wider and thicker than the unaffected contralateral limb.

Conclusion

Harvesting the central third of the patellar tendon during the BPTB procedure after an ACL injury leads to significant changes in the patellar tendon that can last for up to 12 months after the surgery. Further research must focus on the translation of these findings into clinical signs with longest follow-up periods.