Scapholunate Instability

Clearwater, Tampa, St Petersburg, Florida

Scapholunate instability is the most common form of carpal instability or instability of the bones in the wrist. Patients frequently complain of pain and weakness on the dorsal radial aspect of the wrist (“dorsal” being the topside of the hand as opposed to the palm, and the “radial aspect” is the side of the hand the thumb is on).

The eight bones that comprise the wrist are held together by tough bands of ligaments that connect the wrist bones to each other, and to the forearm bones and finger bones.

Scapholunate instability is a disruption of the ligaments that connect the carpal bones that are adjacent to the radius – the larger forearm bone. This disruption of the ligament may or may not result in an increase in interval space between the scaphoid and lunate bones. This instability of the carpal bones may result in weakness, stiffness, chronic pain and often arthritis, if not treated appropriately.

Scapholunate occurs when the scapholunate ligament is completely torn or stretched, allowing the scaphoid and lunate bones to separate or disassociate. The scaphoid may then tilt in a rotatory direction (volar), whereas the lunate bone tilts in a dorsal direction. This allows the two carpal bones to not only separate, but tilt away from each other. This can be seen on x-rays and MRIs. This rotary subluxation of the scaphoid and lunate in relationship to one another is the most common instability pattern of the wrist.

Scapholunate instability can result from several occurrences:

1. Discontinuity of the ligament

2. Complete absence of the scapholunate ligament

3. The occurrence of fraying, thinning and/or irregularity of the ligament

4. Stretched or elongated ligament

Associated wrist pain in scapholunate instability may also result from a direct fracture of the scaphoid bone. The scaphoid, if fractured, is one of the more frequent bones to undergo avascular necrosis , where the bony substance essentially dies.

Partial tears may more commonly affect the weaker volar attachment of the ligaments.

The chronic wrist pain associated with a scapholunate ligament tear is also referred to as scapholunate disassociation. In cases where the scapholunate ligament tears have not resulted in a complete disassociation, ligament fraying, thinning and/or irregularities result in an elongated ligament, which increases carpal space.

A problem associated with scapholunate ligament disruption and chronic instability of the scaphoid can cause the scaphoid to drift more toward the radius bone or proximally, which then results in an advanced scapholunate collapse of the wrist (SLAC). Accelerated degenerative changes may result from this condition.

Conservative treatments for scapholunate instability include immobilizing the injured segment and, obviously, refraining from athletic endeavors during the healing period. There are a variety of conservative measures in the mild or early cases that are effective without surgical intervention, including therapeutic modalities.

Platelet-rich plasma (PRP) has also shown a role in the conservative measures of healing scapholunate instability and even in other ligament injuries. Platelet-Rich Plasma (PRP) therapy captures the healing growth factors that are in a person’s own blood. By injecting the PRP into the damaged area of the wrist, it may help heal the affected area and diminish pain. In addition, there are indications for platelet-rich plasma in healing a variety of conditions, in much the same way that stem cell therapy may help regenerate different types of tissues.

Other courses of treatment involve surgery.

If you continue to suffer with chronic wrist pain caused by scapholunate instability and your current treatment plan leaves you feeling hopeless, perhaps a fresh set of experienced eyes can change your outlook.  Since 1990, Dennis M. Lox, M.D has applied his personal interests in sports medicine, cutting-edge regenerative medicine and chronic pain management to helping patients increase their quality of life. Contact us for an appointment at 727-462-5582.

Dr. Dennis Lox and the Florida Spine Center serve patients within the greater Tampa Bay area, including Clearwater, Tampa and St. Petersburg, as well as all of Florida and the US.

All statements, information or opinions provided by this website are provided for educational purposes only. We do not diagnose nor treat through this website or by telephone. As you consider any treatment, discuss them with your physician.

Regarding platelet-rich plasma or stem cell therapy: Neither statements nor treatments have been evaluated by the FDA. We do not claim that these treatments work for any listed or unlisted condition. Patient testimonials offer only the patient’s impression of how a therapy worked for them – individual results will vary; results are not guaranteed nor warranteed. As you consider any treatment, discuss them with your physician.