Based on the history, physical exam, and radiographs, the diagnosis of scaphoid nonunion advanced collapse (SNAC), stage II was made. The development of degenerative changes following scaphoid nonunion progresses in a characteristic manner, much like in chronic scapholunate ligament insufficiency. Stage I SNAC involves the radial styloid-scaphoid articulation; Stage II involves the scaphocapitate interface, as well as progression of degeneration in the radioscaphoid articulation; and finally Stage III SNAC involves the capitolunate interface with progression of the previously involved joints. Generally, the proximal radioscaphoid and radiolunate articulations are preserved in true SNAC wrists [1]. Stage IV represents pan-carpal arthritis .

Initial treatment for SNAC wrist should almost always be conservative. Activity modification, splinting, nonsteroidal anti-inflammatory medications, and intra-articular corticosteroid injections may be beneficial. Surgical intervention may be indicated when conservative treatment has failed.

Reasonable surgical treatments for advanced SNAC wrist include proximal row carpectomy , scaphoid excision with four-corner arthrodesis , total wrist arthrodesis, and total wrist arthroplasty , although the latter two options are usually reserved for Stage IV disease. For Stage II disease, either a proximal row carpectomy (PRC) or a scaphoid excision and four corner fusion are appropriate treatment options . In younger (less than 50 years of age) patients, we recommend a four corner fusion as the longevity of the radiolunate joint is quite predictable once a solid fusion occurs. The longevity of the capitate head articulation in younger patients following PRC is less predictable with subsequent arthritis a relatively more common finding. In older patients (more than 60 years of age), we generally recommend a proximal row carpectomy. In between 50 and 60 years of age, we favor four corner fusions in active individuals and proximal row carpectomies in the more sedentary.

Scaphoid excision with four-corner arthrodesis is contraindicated in the presence of radiolunate degenerative changes or radiolunate instability (e.g., ulnar carpal translocation due to radioscaphocapitate or long radiolunate ligament insufficiency), as well as in the presence of active infection .

Scaphoid excision with four-corner arthrodesis , with use of a dorsal four corner fusion specific plate and autologous distal radius cancellous bone graft.

Following cast immobilization for 4 weeks and hand therapy for range of motion and strengthening for another 4 weeks, the patient returned to activities of daily living without restriction. At 3 months postoperative, the patient resumed golfing and tennis. Occasional aching in the wrist was noted for the first 3–4 months which ultimately resolved. Radiographs taken at 4 months demonstrated a solid four corner fusion and excellent plate recession (Fig. 25.4a, b)Follow-up examination at 6 months will generally demonstrate range of motion (ROM) of 35° wrist extension and 30° of wrist flexion. In general, wrist flexion lags wrist extension. By 1 year postoperative, average wrist ROM = extension 45° and flexion 35°. Average grip strength at 1 year is 75 % of the contralateral hand.VAS pain scores at 1.5 out of 10 at 6 months and 0.9 out of 10 at 1 year.

While a number of different fixation techniques have been described (e.g., K-wires, screws, staples, various plates, etc.), a good functional result following four-corner arthrodesis is likely more due to technical factors than specific implant or fixation technique chosen [2]. We believe that an adequate amount of quality bone graft is critical; we recommend distal radius autogenous cancellous bone. We caution against the use of the morselized scaphoid as bone graft as this poor quality bone may have contributed to previously reported elevated nonunion rates [2] .