Scapholunate (SL) dissociation happens when the scaphoid and lunate bones in your wrist move apart. Falls on an outstretched hand often cause this condition. Symptoms include wrist pain and swelling. Providers diagnose SL dissociation with a scaphoid shift test, X-rays and MRI. After surgery, you can often recover fully in several months.
Scapholunate (SL) dissociation is when the small bones in your wrist (scaphoid and lunate) move out of alignment. During SL dissociation, a gap forms between the bones. When you use your wrist, these bones move apart (dissociate) from each other.
Scapholunate dissociation usually occurs from an injury to the ligament connecting your scaphoid and lunate bones (scapholunate interosseous ligament).
You may need surgery to treat scapholunate dissociation. But proper treatment followed by physical therapy can help you recover fully.
Scapholunate dissociation can affect anyone no matter their gender, ethnicity or race. But you’re at greatest risk of this condition if you fall on your hand.
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SL dissociation most often occurs from falling on an outstretched hand. This type of fall can tear your scapholunate interosseous ligament (SLIL).
Other causes of SL dissociation may include:
The main symptoms of SL dissociation include:
Your healthcare provider will ask about symptoms and examine your wrist for pain, swelling and tenderness. They may also do the following:
Scapholunate dissociation treatment first includes:
Your provider may refer you to a hand specialist. You will likely need hand surgery within six weeks of your injury.
Your surgeon may perform surgery while you’re asleep under general anesthesia. Or they may do it after numbing your entire upper extremity (regional anesthesia). They will:
You can reduce your risk of scapholunate dissociation by taking steps to prevent falls. These steps may include:
If you don’t get prompt treatment for SL dissociation, complications may include:
If you have surgery for SL dissociation, you’ll need to wear a cast for a few weeks. Once your provider removes your cast, physical therapy can help restore strength to your wrist. You can usually return to your normal activities within a few months.
After treatment for SL dissociation, talk to your doctor about what activities you can safely perform. Specific exercise programs can help you regain strength and range of motion in your wrist.
A note from Cleveland Clinic
Scapholunate (SL) dissociation happens when small bones in your wrist (scaphoid and lunate) misalign. SL dissociation occurs when you injure the ligament connecting these bones. Falling on an outstretched hand usually causes this condition. Symptoms include wrist pain, swelling and tenderness. Providers diagnose scapholunate dissociation with a scaphoid shift test, X-rays, MRI and arthroscopy. Treatment usually includes surgery. With proper treatment, most people with SL dissociation can return to their regular activities in a few months.
Last reviewed by a Cleveland Clinic medical professional on 05/31/2022.
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