Tightening elongated ACL grafts by application of bipolar electromagnetic energy (ligament shrinkage)

In ACL transplants showing elongation with functional deficit but no interruption of structure (Marburg Arthroscopic Score type III) there is the possibility of reinsertion, augmentation, or revision ACL reconstruction to stabilize the joint. Bipolar electromagnetic energy can be used to induce the tightening of elongated ACL transplants. We examined 14 patients with a secondary instability after ACL transplantation (mean 23.6 months). During arthroscopy a type III transplant without signs of nonisometric position was found. The elongated transplants were treated by bipolar application probe. All knees where protected by an unlimited orthosis over a period of 12 weeks. Postoperative follow-up took 9.4 months. There was a significant improvement in subjective discomforts (35.9 to 88.5 points on the Lysholm score), and the Rollimeter test showed a reduction of the ventral tibial translation (13.1 to 2.6 mm). There was a correlation between the degree of chondral damage and a Lysholm score but not between subjective discomforts and the degree of instability. Our findings confirm that elongated ACL transplants can be tightened by applying bipolar electromagnetic energy during rearthroscopy, thus avoiding revision ACL reconstruction in some cases.