Arthroscopic Dorsal Round-Block Capsulo-Ligamentoplasty for Dynamic Scapholunate Instability: An Anatomical Study and Case Series.

Background: Chronic dynamic scapholunate (SL) instability remains difficult to treat. Several treatment options exist. Purpose: We propose an arthroscopic dorsal round-block capsulo-ligamentoplasty technique to treat dynamic scapholunate instability: a dorsal purse-string-like suture around the dorsal aspect of the proximal row, following the course of the dorsal intercarpal ligament (DICL). A Fiberwire suture travels between the radiocarpal and midcarpal space, piercing the attachments of the DICL on the triquetrum and of the scaphotrapezial ligament on the distal scaphoid. It reinforces the DICL and the dorso-capsuloscapholunate septum, also inducing a fibrotic healing. Moreover, it produces an extension lever correcting the scaphoid flexion/pronation. Compared with other capsulodesis techniques, the all-inside dorsal round-block capsulo-ligamentoplasty is theoretically likely to produce less stiffness, without additional damage to the SL complex. The wrist remains practically undamaged after surgery: no bone tunnels, bone anchors, or tendon grafts are required, thus enabling all possible secondary procedures. Data of a cadaveric study and case series illustrate the technique. Conclusion: The arthroscopic dorsal round-block capsulo-ligamentoplasty can be considered to treat chronic dynamic scapholunate instability.