A broken thumb, or thumb fracture, is a common injury that significantly disrupts hand function. Treatment depends entirely on the break’s severity and specific location within the thumb’s two bones (phalanges) and the metacarpal bone. A correct diagnosis through imaging is the first step in determining the proper course of action, which may involve a cast, a splint, or surgery.
Signs of a Broken Thumb
A thumb fracture presents with physical signs that distinguish it from a less severe sprain. Immediate and intense pain at the injury site is the most common indicator, often worsening with any attempt to move or grip an object. This pain is usually accompanied by significant swelling that can spread around the base of the thumb.
Visible deformity is another sign, where the thumb appears misshapen, crooked, or angled unnaturally. A person may also experience a distinct grinding sensation, known as crepitus, when attempting to move the thumb, suggesting bone fragments are rubbing together. Localized tenderness and extensive bruising or discoloration around the area also point toward a fracture. If there is numbness, tingling, or the thumb feels cold, it indicates that blood flow or nerve function may be compromised, requiring immediate medical attention.
Non-Surgical Immobilization Options
For stable fractures, where bone fragments have not moved significantly or can be easily realigned, non-surgical immobilization is used. This approach holds the bones still to allow the natural healing process to occur.
The most common device is a thumb spica cast, designed to immobilize the thumb and wrist while leaving the fingers free. The cast prevents bone fragments from shifting out of alignment during the healing phase, which typically lasts four to six weeks. Alternatively, a removable rigid splint or brace may be used for less severe or non-displaced fractures, offering the advantage of being removed for cleaning and skin checks. Regular X-rays are often taken throughout the immobilization period to ensure the bone remains stable and has not slipped from its correct position.
When Surgical Intervention is Required
Surgery is necessary when a fracture is unstable, significantly displaced, or involves the joint surface, making non-surgical methods insufficient for proper healing. Fractures involving the joint (intra-articular fractures) are concerning because misalignments of even one millimeter can lead to long-term joint instability and post-traumatic arthritis.
Complex fractures at the base of the thumb, such as a Bennett’s fracture or a Rolando’s fracture, almost always require surgical stabilization. A Bennett’s fracture is an unstable break at the base of the thumb metacarpal bone that often subluxates due to the pull of surrounding tendons. A Rolando’s fracture is a more complicated comminuted intra-articular fracture, presenting a Y- or T-shaped pattern at the base of the thumb.
Surgical treatment involves techniques like closed reduction with percutaneous pinning, where metal pins or wires are inserted through the skin to hold the bone fragments in place. More extensive procedures, such as open reduction and internal fixation, use small screws and plates to secure the fragments. These procedures are particularly used for complex breaks or those with larger bone pieces.
Recovery Timeline and Rehabilitation
Regardless of whether the treatment involves a cast or surgery, the initial bone healing phase takes between four to eight weeks, depending on the fracture’s complexity and location. Once the cast, splint, or pins are removed, the thumb and wrist often feel stiff, weak, and limited in their range of motion.
Physical therapy is a necessary step in the recovery process to restore full function to the hand. A hand therapist guides the patient through specific exercises to regain flexibility, improve grip strength, and increase the thumb’s ability to move and oppose the fingers. While the bone is healed after six to eight weeks, it can take up to three to four months to regain full strength and return to high-impact activities like contact sports. Full recovery involves consistent effort with rehabilitation exercises to minimize the risk of chronic stiffness or pain.