Scaphotrapezial trapezoidal arthrosis.

Scaphotrapezial trapezoidal degenerative arthritis as an isolated entity or as a preponderant part of a pantrapezial degenerative process was seen in 49 hands of 34 patients. Pain and weakness were the primary complaints. Point tenderness was present in all but two hands. Significant loss of grasp and pinch strength was noted in 18 hands, and loss of wrist motion occurred in 16 hands. Roentgenographic findings included narrowing of the scaphotrapezial trapezoidal joint space, subarticular cortical sclerosis, and cyst formation. A dorsiflexed position of the scaphoid, with a scapholunate angle of less than 45 degrees, was noted in 38 of the 45 hands. Late collapse of the intercarpal joint with dorsiflexion instability of the lunate also was noted. Twenty-nine hands were treated conservatively by protective splints, corticosteroid injections, and avoidance of exacerbating activities. Surgical treatments consisted of fibrous arthroplasty (four), silicone interposition arthroplasty (six), trapezial replacement arthroplasty (three), arthrodesis (five), joint debridement (one), and trapezial excision (one). Late results were more encouraging than were early results and were moderately satisfactory for each method. Improvement in grasp and pinch strength was most predictable for arthrodesis, although wrist motion was diminished.