The scaphoid bone is one of the eight carpal bones in the wrist, located on the thumb side, just above the radius bone. It is the largest bone in the first row of wrist bones and coordinates motion and stability between the carpal rows. A scaphoid fracture, a break in this boat-shaped bone, is the most frequently fractured carpal bone, typically resulting from a fall onto an outstretched hand. This injury is unique because the scaphoid has a limited blood supply, making healing slow and uncertain. Specific treatment is necessary to prevent long-term complications, such as non-union, where the bone fragments fail to fuse.
Identifying a Scaphoid Fracture
A person with a scaphoid fracture often experiences pain and swelling on the thumb side of the wrist. This injury may be mistaken for a simple wrist sprain because a visible deformity is rare. The pain is worsened by gripping, lifting, or trying to pinch something. The most telling symptom is tenderness in the “anatomic snuffbox,” a triangular depression on the back of the wrist near the base of the thumb.
Diagnosis commonly begins with a physical exam and standard X-rays of the wrist. However, a scaphoid fracture can be “occult,” meaning it is not visible on initial X-rays following the injury. If X-rays are negative but a fracture is still suspected, the wrist is often immobilized, and follow-up imaging is scheduled. Advanced imaging, such as a Computed Tomography (CT) scan or Magnetic Resonance Imaging (MRI), may be used to confirm the fracture, especially if initial X-rays are inconclusive. An MRI is useful because it can detect the fracture before it is visible on X-ray and can also show damage to surrounding soft tissues.
Non-Surgical Treatment Options
Non-surgical treatment is reserved for acute fractures that are non-displaced and stable. The primary method involves immobilizing the wrist in a cast, often a thumb spica cast. This cast includes the thumb and extends below the elbow to prevent motion, holding the bone fragments in place to allow them to heal.
The duration of immobilization is highly variable, often ranging from six to twelve weeks, and sometimes longer, depending on the fracture’s location. Fractures in the distal third of the scaphoid, closer to the thumb, usually heal faster (six to eight weeks) due to a better blood supply. Fractures in the middle (waist) or proximal third, closer to the forearm, require longer casting times, sometimes up to 24 weeks.
Healing is slow because the scaphoid’s blood supply enters mainly from the distal end and flows backward toward the proximal pole. A fracture in the middle or proximal part can interrupt this retrograde blood flow, starving the proximal fragment of oxygen and nutrients. Repeat imaging, such as X-rays or CT scans, is necessary every few weeks to monitor the healing process and confirm that the bone is fusing. If a fracture shows no sign of healing after a prolonged period, it may require surgical intervention.
When Surgery Becomes Necessary
Surgical intervention is advised for fractures that are displaced by more than a millimeter, involve the proximal pole, or have failed to heal after prolonged casting. Displaced fractures are associated with a high rate of non-union and complications like avascular necrosis. Surgery provides immediate stability to the fracture fragments, promoting more predictable healing.
The most common procedure is Open Reduction and Internal Fixation (ORIF), where the surgeon makes an incision to visualize and realign the fracture fragments. The bone is then stabilized using internal hardware, typically a specialized compression screw or pins buried within the bone. For fractures that have failed to heal (non-unions), the procedure almost always involves bone grafting.
Bone grafting involves placing bone material into the fracture gap to stimulate new bone growth. This material may be taken from another part of the patient’s body, such as the distal radius, and can be either non-vascularized or vascularized. A vascularized graft is taken with its own attached blood supply, which is often preferred for non-unions, especially if avascular necrosis is present. While surgery can lead to quicker mobilization and higher union rates, it carries risks, including infection, anesthetic complications, and the potential for hardware irritation or removal.
Life After Treatment: Recovery and Rehabilitation
Following treatment, the recovery phase focuses on restoring the function of the wrist and hand. Once the cast is removed or the bone is determined to be stable, a physical therapy (PT) program is initiated. PT focuses on regaining the range of motion in the wrist and thumb, which is often limited due to the long period of immobilization.
Therapy gradually progresses to strengthening exercises to rebuild muscle mass and grip strength lost during treatment. Returning to heavy lifting, manual labor, or contact sports is a gradual process that typically takes several months after the bone is confirmed to be fully healed. The full timeline for recovery is highly individualized and depends on the initial severity of the fracture and adherence to rehabilitation.
Even after the fracture has healed, there is a risk of long-term complications. Avascular necrosis (AVN) is a unique risk where the blood supply to a bone fragment is permanently lost, causing the tissue to die. If the scaphoid does not heal correctly, it can lead to Scaphoid Non-union Advanced Collapse (SNAC wrist), a form of degenerative arthritis that causes chronic pain and stiffness. Early diagnosis and appropriate treatment minimize the risk of these long-term issues.