ARTHRITIS OF WRIST
Primary osteoarthritis of the wrist is exceedingly rare, and most often wrist arthritis develops after trauma to the joint. Intra-articular malunion after radius fracture, scapholunate interrosseous ligament disruption (SLAC), and scaphoid nonunion (SNAC) all are common causes of articular destruction of the wrist.
SLAC and SNAC wrist share a common pathophysiology of actual or relative flexion of the scaphoid and altered loading of the radiocarpal and midcarpal articulations. There is a defined sequence of arthritic progression first involving the scaphoid and radial styloid (stage I), involvement of the entire radioscaphoid joint (stage II), capitolunate degeneration (stage III), and pancarpal arthritis (stage IV). The radiolunate joint is preserved except in the most advanced stages of disease. Nonoperative treatment consists of activity modification, nonsteroidal anti-inflammatory agents, splinting, and judicious use of intra-articular corticosteroid injection. Operative treatment is reserved for those who fail conservative treatment and have pain or deformity that limits their daily activities. Surgical options can be grouped into motion-sparing versus motion-eliminating procedures. Total wrist fusion is the best option for the heavy laborer and/or patients with pancarpal degeneration. Patients with sparing of the midcarpal joint are candidates for proximal row carpectomy, which is the elimination of the scaphoid, lunate, and triquetrum. Stability is maintained by the careful preservation of the volar radioscaphocapitate ligament, and the wrist “runs” on the newly created radiocapitate articulation. Proximal row carpectomy may not be appropriate in the young/heavy laborer. When the radiolunate articulation is preserved, some form of midcarpal fusion can provide excellent pain relief and acceptable motion. Midcarpal fusion is always accompanied by scaphoid excision and then is achieved via either capitolunate arthrodesis or four-bone fusion. Total wrist arthroplasty is a motion-sparing procedure that can provide excellent pain relief and preserve motion. Current designs are appropriate for the patient with pancarpal degeneration with low demand for activities requiring wrist motion.
Radiocarpal destruction secondary to distal radius malunion can be managed with either elimination of the radiocarpal joint via radioscapholunate fusion or total wrist arthrodesis/arthroplasty. Again, the surgical decision is based on patient factors as well as on direct intraoperative inspection of the anticipated preserved articulations.