What's In My Bag? 3.5 mm SwiveLock with Steven Lee, MD
Q. What made you start using the SwiveLock anchor for scapholunate dissociations?
A. Currently, treatments of scapholunate dissociations are suboptimal and often unsatisfactory. Direct repairs are rarely successful and typically fall apart so we rely on a secondary procedure like a capsulodesis to help control DISI deformity. Therefore, a reconstruction makes more sense. However, current reconstructions are either too complex to perform or have weak fixation strength. SwiveLocks are easy to use and have unbelievably strong fixation strength, allowing the tendon to heal into the bone as opposed to the surface of the bone.
Q. Can you describe your operating technique when using these SwiveLocks?
A. The operative technique entails using a tendon graft to reconstruct the dorsal portion of the scapholunate interosseous ligament as well as to control the relationship of the lunate to the distal pole of the scaphoid. After restoring the DISI deformity to normal alignment using K-wires, the tendon graft along with a 2-0 FiberLoop is dunked into the proximal pole of the scaphoid with a modified 3.5 mm PEEK SwiveLock. Both the tendon graft and the FiberLoop are dunked into the lunate and secured with another 3.5 mm SwiveLock. Then the graft and FiberLoop is dunked into the distal pole of the scaphoid with a third SwiveLock. The tendon graft is reinforced with the double-stranded 2-0 FiberLoop as an internal brace to provide extra fixation strength during the time that the tendon graft is healing into the bone. I have been leaving the K-wires in for added provisional fixation, and taking them out at about six weeks.
Q. What are a few of the significant advantages over current techniques you have tried?
A. The advantages of this technique are that it does not rely on the healing of the native ligament which in my mind usually does not heal after a direct repair (sort of like an ACL). Therefore, it can be used acutely or chronically as long as significant arthritis hasn’t set in and the carpal bones are still reducible. This reconstruction addresses not only SLIL, but also the flexion of the scaphoid and the extension of the lunate. Finally, it’s relatively easy and fast to do. Typically this surgery takes about 30-45 minutes to perform.
Q. What is your post-op protocol?
A. I put the patient into a plaster thumb spica splint immediately post-op, then change them over to an orthoplasty type thumb spica splint, which stays on until about six weeks post-op. I take out the K-wires and start on a hand therapy program that typically goes for about six weeks.
The views expressed in this post reflect the experience and opinions of the presenting surgeon and do not necessarily reflect those of Arthrex Inc.