Anatomic Anterior Cruciate Ligament Reconstruction Using Hamstring Tendons Restores Quantitative Pivot Shift

Area of Science:

• Orthopedic Surgery
• Sports Medicine
• Biomechanical Engineering

Background:

• The precise restoration of rotatory knee laxity after anterior cruciate ligament (ACL) reconstruction remains unclear.
• The optimal graft restraint for replicating a healthy knee's stability is not fully defined.

Purpose of the Study:

• To quantify the efficacy of single-bundle anatomic ACL reconstruction using hamstring tendons in mitigating the pivot-shift phenomenon immediately post-surgery.

Main Methods:

• A case series (Level 4 evidence) involving 89 patients across 4 international centers.
• Utilized inertial sensors and image analysis to measure tibial acceleration and lateral compartment translation during the pivot-shift test.
• Compared side-to-side laxity preoperatively and postoperatively under anesthesia.

Main Results:

• A statistically significant reduction in rotatory knee laxity was observed postoperatively compared to preoperatively (P < .001 for both measurement methods).
• Postoperative measurements indicated lower laxity in the reconstructed knee compared to the contralateral healthy knee.
• Both inertial sensors and image analysis successfully detected the reduction in pivot shift after surgery.

Conclusions:

• Anatomic single-bundle ACL reconstruction significantly reduces the pivot-shift phenomenon.
• Inertial sensors and image analysis are reliable tools for quantitatively assessing pivot-shift restoration post-ACL reconstruction.
• Future studies should investigate long-term pivot-shift control and its correlation with return to activity.