Wrist pain can develop for many reasons, but one of the most common patterns of progressive wrist arthritis seen by hand and wrist specialists is a condition known as SLAC wrist. SLAC stands for Scapholunate Advanced Collapse, a form of wrist arthritis that develops after injury to one of the wrist's most important stabilizing ligaments.
SLAC wrist typically develops gradually over time. Many patients initially experience intermittent pain or weakness and may not realize that a prior wrist injury is contributing to their symptoms. As the condition progresses, pain, stiffness, loss of motion, and diminished grip strength can begin to interfere with work, recreation, and everyday activities.
Understanding how SLAC wrist develops and the treatment options available can help patients better understand their diagnosis and potential path forward.
What Is SLAC Wrist?
SLAC wrist is a specific pattern of degenerative arthritis that occurs when the scapholunate ligament becomes injured and no longer adequately stabilizes the wrist.
The scapholunate ligament connects the scaphoid and lunate, two small but critically important bones within the wrist. Together, these bones help coordinate normal wrist motion and distribute forces across the joint.
When the ligament is torn or becomes chronically incompetent, the scaphoid and lunate gradually move abnormally relative to one another. This altered mechanics creates uneven loading across the wrist joint. Over time, the cartilage begins to wear away in a predictable pattern, eventually leading to arthritis.
Because this process follows a characteristic progression, the resulting arthritis pattern is referred to as Scapholunate Advanced Collapse.
What Causes SLAC Wrist?
The most common cause of SLAC wrist is a chronic scapholunate ligament injury.
Many patients can recall a prior fall onto an outstretched hand, sports injury, work-related injury, or significant wrist sprain. In some cases, the original injury occurred years earlier and was never formally diagnosed.
Although not every scapholunate ligament injury progresses to arthritis, persistent instability can gradually damage the cartilage surfaces of the wrist.
Common causes include:
- Scapholunate ligament tears
- Previous wrist trauma
- Certain scaphoid fractures
- Chronic wrist instability
- Repetitive loading of an already unstable wrist
The progression from ligament injury to arthritis often occurs slowly, sometimes over many years.
What Are the Symptoms of SLAC Wrist?
Symptoms generally worsen gradually as arthritis advances.
Common symptoms include:
- Pain with activity
- Decreased grip strength
- Loss of wrist motion
- Difficulty lifting or carrying objects
- Pain when pushing up from a chair
- Clicking, popping, or grinding sensations
- Swelling around the wrist
- Progressive weakness
Many patients notice that activities they once performed comfortably become increasingly painful. Golf, tennis, pickleball, weight training, manual labor, and routine household activities may all become more difficult as the arthritis progresses.
How Is SLAC Wrist Diagnosed?
Diagnosis begins with a detailed history and physical examination.
During the evaluation, a hand and wrist specialist assesses:
- Wrist motion
- Grip strength
- Areas of tenderness
- Mechanical symptoms
- Signs of instability
- Overall wrist function
Standard wrist X-rays are often the most important diagnostic study. In many cases, characteristic radiographic findings allow the diagnosis to be established without advanced imaging.
Typical findings may include:
- Widening between the scaphoid and lunate
- Abnormal wrist alignment
- Progressive joint space narrowing
- Bone spur formation
- Arthritis in characteristic locations within the wrist
MRI or CT imaging may occasionally be useful when evaluating associated pathology or planning surgery, but standard radiographs often provide the key information needed to identify SLAC wrist.
Stages of SLAC Wrist
SLAC wrist generally progresses through a predictable sequence of arthritic changes.
Stage I
Arthritic changes begin between the radial styloid and the scaphoid.
Patients may experience relatively mild symptoms and often maintain good wrist motion.
Stage II
Arthritis progresses throughout the radioscaphoid joint.
Pain, stiffness, and activity limitations often become more noticeable during this stage.
Stage III
Arthritic changes extend into the midcarpal joint, particularly between the capitate and lunate.
Patients frequently experience significant pain, decreased motion, reduced grip strength, and greater functional limitations.
An important feature of many SLAC wrists is that the radiolunate joint often remains relatively preserved despite substantial arthritis elsewhere in the wrist. This preservation can make certain motion-preserving surgical procedures possible even in more advanced cases.
Can SLAC Wrist Be Treated Without Surgery?
Many patients initially benefit from nonsurgical treatment.
Conservative treatment options may include:
- Activity modification
- Wrist bracing
- Anti-inflammatory medications
- Corticosteroid injections
- Hand therapy
These treatments are designed to reduce symptoms and improve function. While they may provide meaningful relief, they do not reverse the underlying arthritic process.
For some patients, conservative treatment remains effective for years. Others eventually reach a point where pain and functional limitations persist despite appropriate nonoperative management.
When Is Surgery Considered?
Surgery may be considered when:
- Pain interferes with daily activities
- Conservative treatment no longer provides adequate relief
- Grip strength continues to decline
- Wrist motion becomes increasingly limited
- Symptoms significantly affect work, recreation, or quality of life
The most appropriate procedure depends on multiple factors, including the patient's age, activity level, occupation, goals, degree of arthritis, and the condition of the remaining cartilage surfaces.
Surgical Options for SLAC Wrist
Several surgical options may be appropriate depending on the stage of disease and the specific pattern of arthritis.
Proximal Row Carpectomy (PRC)
A proximal row carpectomy involves removal of three bones from the proximal row of the wrist.
For appropriately selected patients, PRC can provide reliable pain relief while preserving meaningful wrist motion and function.
Potential advantages include:
- Pain reduction
- Preservation of wrist motion
- No requirement for bone fusion
- Durable functional outcomes in properly selected patients
Four-Corner Fusion
A four-corner fusion involves removal of the scaphoid and fusion of several remaining wrist bones.
This procedure is designed to reduce pain while preserving a portion of normal wrist motion.
Four-corner fusion remains a commonly utilized motion-preserving option for appropriately selected patients with more advanced SLAC wrist.
Wrist Denervation
For selected patients, wrist denervation procedures may help reduce chronic wrist pain while maintaining existing wrist motion.
These procedures involve addressing specific sensory nerve branches that transmit pain signals from the wrist.
Total Wrist Fusion
In cases of severe arthritis involving multiple wrist articulations, total wrist fusion may provide reliable and durable pain relief.
Although wrist motion is eliminated, many patients experience substantial improvements in comfort, strength, and overall function.
What Is Recovery Like?
Recovery depends on the procedure performed, the severity of arthritis, and individual patient factors.
Most patients require a period of immobilization followed by progressive rehabilitation.
The primary goals of treatment include:
- Reducing pain
- Improving function
- Restoring strength
- Preserving motion whenever possible
- Returning to desired activities
Recovery may range from several weeks to several months depending on the specific procedure and the patient's overall condition.
When Should You See a Hand and Wrist Specialist?
Persistent wrist pain should not be ignored, particularly when symptoms continue despite rest or conservative treatment.
Evaluation may be appropriate for patients experiencing:
- Ongoing wrist pain
- Decreased grip strength
- Clicking, grinding, or mechanical symptoms
- Progressive loss of motion
- Difficulty performing work, sports, or daily activities
Early evaluation may identify underlying ligament injuries or developing arthritis before symptoms become more severe.
Conclusion
SLAC wrist is one of the most common forms of progressive wrist arthritis encountered in hand and upper extremity practice. It develops when injury to the scapholunate ligament alters normal wrist mechanics, eventually leading to cartilage wear and arthritis in a characteristic pattern.
Although SLAC wrist can cause significant pain, weakness, and loss of motion, a variety of effective treatment options are available. Depending on the stage of arthritis and a patient's goals, treatment may range from bracing and injections to advanced motion-preserving procedures such as proximal row carpectomy and four-corner fusion.
A thorough evaluation can help determine the extent of arthritis and identify the treatment approach best suited to the individual patient.
