Biomechanics of ACL reconstruction may differ with adjustable-, fixed-loop cortical devices
Although some adjustable-loop femoral cortical devices have been shown to provide strong fixation in terms of ultimate load to mechanical failure in cases of ACL reconstruction, results published in The Orthopaedic Journal of Sports Medicine showed a fixed-loop cortical device had the least cyclic displacement.
“There is significant promise in these devices, both in their strength and cyclic displacement, but there are, indeed, statistical differences and the actual numbers of which may become clinically significant in the right scenario,” Jonathan T. Bravman, MD, sports medicine and shoulder surgeon, associate professor and director of sports medicine research at CU Sports Medicine, told Healio.com/Orthopedics.
Through a systematic review of multiple databases, two independent reviewers identified six studies that compared the biomechanical strength of fixed- and adjustable-loop cortical suspension devices for ACL reconstruction with isolated device or specimen set-ups using porcine femora and bovine flexor tendons. Bravman and his colleagues extracted data on displacement during cyclic loading, ultimate load to failure and mode of failure of the different cortical suspension devices.
“One of the adjustable-loop devices, specifically what is called the ToggleLoc, was the strongest in regard to load to failure,” Bravman said. “That was, though a small difference, indeed a statistically significant difference from the Endobutton closed-loop device.”
The researchers also found the ToggleLoc with ZipLoop adjustable-loop device (Biomet) had a stronger fixation when compared with the TightRope RT adjustable-loop device (Arthrex).
However, when it came to cyclic displacement, results showed the least displacement with the Endobutton CL (Smith & Nephew) followed by ToggleLoc with ZipLoop and TightRope RT. Researchers noted suture failure occurred in 83.8% of TightRope RT devices, 69.4% of ToggleLoc with ZipLoop devices and 60.3% of Endobutton CL devices.
“The application of these [devices] and the ability for the surgeon to potentially change their technique or modify their technique based on certain characteristics of the patient is important,” Bravman said. “It is important to understand the subtle differences in regard to how these devices are both deployed and tensioned.” – by Casey Tingle
Disclosures: Bravman reports he is a consultant for DJ Orthopaedics, Shukla Medical, Encore Medical and Smith & Nephew; receives royalties from Shukla Medical; receives research support from Stryker; received hospitality payments from Encore Medical and Smith & Nephew; and received fellowship funding from Smith & Nephew, Mitek and Stryker. Please see the full study for a list of all other authors’ relevant financial disclosures.