Diagnosis: SLAC Wrist
Scapholunate advanced collapse (SLAC) is the most common pattern for
degenerative osteoarthritis in the wrist. Non-union of a scaphoid
fracture and chronic untreated scapholunate dissociation are two common
injuries which may alter the location or position of the scaphoid. Over
time, abnormal loading resulting from mal-alignment of a wrist bone
causes damage to several joint surfaces. As the condition persists,
other wrist bones may experience migration and mal-positioning. End
stage SLAC wrist involves collapse of the scapholunate joint as both the
scaphoid and lunate bones are rotated out of a normal, functional
SLAC wrist may not present any symptoms, though some patients notice
pain or discomfort following increased activity or overuse of the wrist.
Often, this condition is diagnosed when a patient presents a secondary
problem such as carpal tunnel syndrome. Swelling, weakness, pain, and
decreased wrist motion may indicate SLAC wrist.
Conservative options include splinting to reduce wrist motion.
Anti-inflammatory medications or steroid injections may temporarily
reduce pain and swelling.
conservative treatment is not effective, surgery may be recommended to
alleviate pain and prevent further damage to the wrist. Options may
include proximal row carpectomy and wrist fusion, depending on the level
of damage to the joint.
Proximal row carpectomy involves excision (removal) of the scaphoid,
lunate, and triquetrum bones and allows for better preservation of
strength and motion. The wrist will be splinted for 4 weeks, at which
point range of motion exercises will be initiated. About 3 months after
surgery, strengthening exercises may begin.
Wrist fusion may be more successful at alleviating pain, though motion
is limited. Surgery involves placement of an implant, typically a metal
plate and screws. A short arm splint is worn until fusion takes place,
typically 6-8 weeks after surgery.