Wrist Instability (Scapholunate Ligament Injuries): Overview

Wrist Instability (Scapholunate Ligament Injuries): Overview

This video will provide an overview of scapholunate joint injuries. The scapholunate joint lies between the scaphoid and lunate bones of the wrist. Injuries to this joint often involve the scapholunate ligament.

Typically, injuries to this joint and ligament are often accompanied by other nearby ligament injuries. They can also be associated with wrist fractures. The scapholunate ligament is the most injured ligament in the wrist.

Damage to this ligament can happen abruptly, as in a traumatic injury to the wrist. Most commonly, this occurs with a fall on an outstretched hand. These ligament injuries can also be seen over time in those that repetitively load the wrist, like a gymnast.

While these injuries are most likely to be seen in young patients, they can occur in patients over time with other degenerative conditions like rheumatoid arthritis or those with excessive laxity or mobility in the joints.

Injuries to this ligament vary in severity. They are classified as partial or total tears and are graded based on additional instability in the joint and malalignment in the wrist bones. Often these injuries worsen over time.

It may be months from the initial injury that a patient will develop instability in the joint. If these injuries are not treated, they can progress to a pattern of arthritis known as scapholunate advanced collapse. This is referred to as a SLAC wrist.

Patients with injury to this joint often note pain on the top of the wrist, closer to the thumb. Clicking or clunking may be reported with wrist movement, along with decreased range of motion and strength. Pain may be worsened by loading the wrist, such as in a push-up position.

A health care provider will make the diagnosis of these injuries based on a combination of factors including history, exam findings, and imaging. There are specific tests a health care provider may perform to localize a patient's symptoms if injury to this joint is suspected.

In addition, multiple wrist x-rays will be done looking for abnormality in the alignment of the bones. One malalignment pattern that can occur is a gap between the scaphoid and lunate. While advanced imaging such as an MRI may be done and are useful, these tears can be difficult to localize.

To improve the accuracy of diagnosing these injuries, a health care provider may advise performing a wrist arthroscopy in which a small camera will be used to visualize the joint directly. Given this diagnosis can be difficult to detect along with the progressive nature, it is important patients seek a health care provider with expertise in wrist injuries to make the proper diagnosis and help develop a treatment plan.

Making the diagnosis early is critical in preventing the progression of complications in this injury.