Introduction: Three direct volar arthroscopic portals to the wrist have been previously described: 2 radiocarpal and 1 midcarpal. This study aims at systematically describing 4 volar arthroscopic portals through mini-invasive incisions using inside-out approach from known posterior portals. Method: Four arthroscopic volar wrist portals were studied on 6 hand specimens with an inside/out technique: a radial radiocarpal approach (RRCA), an ulnar radiocarpal approach (URCA), a radial midcarpal approach (RMCA), and an ulnar midcarpal approach (UMCA). Each volar approach corresponded to a posterior approach: a 3/4 portal for RRCA, a 4/5 portal for URCA, a posterior radial midcarpal approach for RMCA, and a posterior ulnar midcarpal approach for UMCA. Results: The average range of motion of the scope through the RRCA was 65° of radial inclination and 71.66° of ulnar inclination, through the URCA was 62.5° in radial inclination and 64.16° in ulnar inclination, through the RMCA was 61.66° in radial inclination and 60° in ulnar inclination, and through the UMCA was 59.16° in radial inclination and 68.33° in radial inclination. No iatrogenic injury to important anatomical structures was noted. Conclusions: Results showed it was possible to perform these 4 volar portals through an inside/out technique with incisions mirroring the posterior portals. They were easy to perform, safe, and seemed useful in indications for ligament or bony intracarpal repairs.
