Innovations in arthroscopic management of Basal joint arthritis of the thumb.

Thumb arthroscopy and arthroscopically assisted treatment of the thumb are safe and effective techniques. This report describes technical innovations particularly useful in the surgical performance of arthroscopically assisted treatment of basal joint arthritis. (1) With adduction and hyperextension of the thumb, the bony landmarks are easier to palpate and a volar radial soft spot is clearly defined between the trapezium and metacarpal (i.e., the adduction-hyperextension maneuver). (2) After the distension of the joint with saline solution, the thumb automatically abducts and flexes if the capsule has been distended successfully (i.e., the flexion-abduction sign). (3) The radial and ulnar borders of the proximal phalanx and the local tendons can serve as external landmarks if fluid extravasation occurred. (4) Finally, the simultaneous use of the 3 portals described in the first carpometacarpal joint is very effective for better visualization and performance of the procedures in this joint (i.e., the 3-portal technique). We propose a new description of the portals for carpometacarpal arthroscopy as follows: (1) volar portal, which is just distal to the oblique ridge of the trapezium following a line referencing the radial edge of the flexor carpi radialis; (2) ulnar portal, which is just ulnar to the extensor pollicis brevis; and (3) radial portal, which is just radial to the abductor pollicis longus.