Summary Various forms of wrist arthritis based on location SLAC wrist (scapholunate advanced collapse) most common STT arthrosis second most common SNAC (scaphoid nonunion advanced collapse) DRUJ arthrosis Pisotriquetrial arthrosis Etiology Mechanism degenerative primary OA posttraumatic leads to SLAC/SNAC/DRUJ inflammatory Rheumatoid arthritis congenital may be secondary to Madelung's deformity idiopathic may secondary to Kienbock's or Preiser's disease Pathoanatomy SLAC Injury to SL ligament --> palmar rotary subluxation of scaphoid --> incongruency of joint surfaces --> arthrosis of radiocarpal joint --> arthrosis of capitolunate joint radiolunate typically spared SNAC proximal portion of scaphoid remains attached to lunate while distal scaphoid flexes leads to early arthritis between radial styloid and distal scaphoid like SLAC, radiolunate typically spared Rheumatoid arthritis wrist becomes supinated, palmarly dislocated, radially deviated, and ulnarly translocated early disruption of DRUJ leads to dorsal subluxation of ulna (Caput-ulna) Anatomy Wrist ligaments and biomechanics Imaging Radiographs obtain standard hand series with additional views to visualize specific joints pisotriquetral joint (pisotriquetral arthrosis) obtain lateral in 30 degrees of supination Treatment Nonoperative NSAIDs, bracing, intra-articular steroid injections indications first line of treatment for mild to moderate symptoms Operative aimed at addressing diseased area SLAC SNAC Pisotriquetrial arthritis excision of pisiform in refractory cases DRUJ abutment syndrome & arthrosis distal ulna resection (Darrach procedure) Sauvé-Kapandji procedure partial ulna resection and interposition ulnar head replacement can be used as primary procedure, or as salvage for failed Darrach early results are promising, long-term results pending Rheumatoid arthritis