Due to lack of stability from the distorted scaphoid, a DISI can be developed. Scaphoid Non-union Advanced collapse (SNAC) is the pattern of osteoarthritis that eventually develops by this process. Stages
Post-traumatic osteoarthritis can be classified into four stages. These stages are similar between SLAC and SNAC wrists. Each stage has a different treatment. Stage I: the osteoarthritis is only localized in the distal scaphoid and radial styloid. Stage II: the osteoarthritis is localized in the entire radioscaphoid joint. Stage III: the osteoarthritis is localized in the entire radioscaphoid joint with involvement of the capitolunate joint. Stage IV: the osteoarthritis is located in the entire radiocarpal joint and in the intercarpal joints. It also may involve the distal radio-ulnar joint (DRUJ). Signs and symptoms
The most common initial symptom of wrist osteoarthritis is joint pain. The pain is brought on by activity and increases when there is activity after resting. Other signs and symptoms, as with any joint affected by osteoarthritis, include:

Morning stiffness, which usually lasts less than 30 minutes. This is also present in patients with rheumatoid arthritis, but in those patients this typically lasts for more than 45 minutes. Swelling of the wrist. Crepitus (crackling), which is felt when the hand is moved passively. Joint locking, where the joint is fixed in an extended position. Joint instability.These symptoms can lead to loss of function and less daily activity. Mechanism
In order to understand the cause of post-traumatic wrist osteoarthritis it is important to know and understand the anatomy of the wrist.
Treatment
Post-traumatic wrist osteoarthritis can be treated conservatively or with a surgical intervention. In many patients, a conservative (non-surgical) approach is sufficient. Because osteoarthritis is progressive and symptoms may get worse, surgical treatment is advised in any stage. Stage I
For stage I, normally, nonsurgical treatment is sufficient. This type of therapy includes the use of splint or cast immobilization, injections of corticosteroid in the pain causing joints and the use of a systemic non-steroidal anti-inflammatory drug to reduce pain and improve the functional use of the affected joint. However, the amount of pain that can be suppressed by nonsurgical therapy is limited and with the progression of the wrist osteoarthritis surgical treatment is inevitable.In stage I surgical treatment often consists of neurectomy of the posterior interosseous nerve and is often combined with other procedures. In the case of a SLAC, the scapholunate ligament can be reconstructed in combination with a radial styloidectomy, in which the radial styloid is surgically removed from the distal radius. In the case of a SNAC, the scaphoid can be reconstructed by fixating the scaphoid with a screw or by placing a bone graft (Matti-Russe procedure) to increase the stability of the scaphoid. Stage II
In the treatment of stage II wrist osteoarthritis, there are two treatment options that have proved to be most successful. The first treatment option is proximal row carpectomy. During this surgical intervention the proximal row of the carpal bones is removed (scaphoid, lunate, triquetrum, pisiform).