Scaphotrapeziotrapezoid Joint Arthroplasty

Long-standing scaphotrapeziotrapezoid (STT) arthritis recalcitrant to nonoperative treatment

Dorsoradial incision that begins at Lister’s tubercle, traverses the anatomical snuffbox, and ends at the scaphotrapeziotrapezoid (STT) joint. Incision can be curved or zigzag configuration (Fig. 49-1).
Protect the radial sensory nerves and lateral antebrachial cutaneous branches using loupe magnification.
Expose the STT joint between the extensor pollicis brevis (EPB) (first compartment) and extensor pollicis longus (EPL) tendons. The deep branch of the radial artery resides just proximal to the STT joint and must be protected (Fig. 49-2).
A longitudinal arthrotomy is performed from the radial styloid to the distal scaphoid (S). The distal scaphoid fragment is identified.
The distal one fourth to one third of the scaphoid is removed with an oscillating saw or osteotome. Sharp dissection of the volar carpal ligaments around the distal scaphoid is required (Fig. 49-3).
An elongated radial styloid may prevent adequate exposure of the scaphoid. This enlarged styloid can be removed by subperiosteal exposure of the first compartment followed by radial styloidectomy.
Adequate excision has been performed when there is no impingement between the remaining scaphoid and the trapeziotrapezoid joint during on wrist motion.
The arthrotomy is closed by reapproximation of the capsular flap. The EPL is left transposed from its third compartment if transposition is needed for exposure.