Scapholunate (SL) Ligament Tear

What it is

The scapholunate ligament connects the scaphoid and lunate bones in the middle of the wrist and is essential for smooth, painless motion. Injuries range from stretching to complete tears, and any of them can make the wrist painful and unstable.

What causes it

Usually a fall onto the hand that bends the wrist backward. The ligament can also stretch out over time from repeated strain, age, or long-standing inflammation such as gout.

Symptoms

• Pain and swelling, often on the back of the wrist
• Pain bending the wrist backward
• Limited motion, weakness, or popping and grinding

Some people only notice a problem years after the original injury.

Diagnosis

Diagnosis can be difficult. An examination is compared with the other wrist, and X-rays may show a gap between the scaphoid and lunate. An MRI, sometimes with dye (MR arthrogram), or wrist arthroscopy can show the ligament directly.

Treatment

Because a torn SL ligament does not heal on its own and can lead to arthritis (SLAC wrist), treatment aims to reduce pain and keep the wrist bones aligned.

Recent injuries: a splint or cast and rest for six weeks or more, sometimes followed by therapy. Injections and anti-inflammatories ease pain but do not realign the bones.

Surgery: repair or reconstruction of the ligament, arthroscopically or through an incision. The wrist may be stiffer afterward, but it is more stable and usually less painful.

Long-standing injuries: when arthritis has already developed, the goal is pain relief and preserving function. Options include cutting the small pain nerves to the wrist (denervation), removing some wrist bones, or partial wrist fusion.