A dislocated thumb occurs when the bones of one of the thumb’s joints are forced out of their normal alignment. This usually happens at the metacarpophalangeal (MCP) joint near the base, or the interphalangeal (IP) joint closer to the tip. The injury typically results from a forceful impact or sudden hyperextension, such as falling onto an outstretched hand. Because the thumb is vital for hand function, immediate medical evaluation and treatment are necessary to ensure proper healing and prevent complications.
Recognizing a Dislocated Thumb
A dislocated thumb presents with immediate and clear signs that distinguish it from a less severe sprain or fracture. The most definitive indicator is an obvious deformity where the joint looks visibly crooked, bent at an unusual angle, or shortened compared to the other thumb. Intense, severe pain occurs instantly upon injury. Swelling and bruising develop quickly around the joint.
Movement of the affected joint will be extremely painful or completely impossible, unlike a simple sprain. Numbness or tingling may also be felt if nerves have been stretched or compressed by the displaced bone.
Immediate Steps Before Medical Care
The immediate priority is to stabilize the injury and seek professional medical attention. The hand and thumb should be immobilized in the most comfortable position using a makeshift splint, such as a rolled magazine or a rigid object secured gently with a bandage. Keeping the hand still helps prevent further trauma to the surrounding ligaments, nerves, and blood vessels.
To manage swelling and pain, apply a cold compress or ice pack to the injured area, wrapped in a cloth or towel to protect the skin. Elevating the hand above the level of the heart can also help limit swelling.
Do not attempt to “pop” or force the thumb back into place. This action, known as self-reduction, can cause severe and irreversible damage to the joint capsule, blood vessels, tendons, or nerves, complicating medical treatment.
Professional Treatment Options
Upon arrival at a medical facility, the diagnosis is confirmed with X-rays. Imaging assesses the exact nature of the dislocation, determines the presence of any associated fractures, and evaluates the degree of displacement. This is performed before any manipulation to guide the treatment plan.
The initial and most common treatment is closed reduction, where a healthcare professional manually manipulates the bones back into their correct anatomical position without surgery. Closed reduction is performed after the patient receives appropriate local or regional anesthesia to ensure comfort and allow the surrounding muscles to relax. The technique involves applying axial traction to the thumb and specific pressure to guide the joint back into the socket.
After the reduction is complete, a second set of X-rays verifies that the joint has been fully and correctly realigned. The joint is then immobilized, often in a thumb spica cast or splint, to protect the healing soft tissues.
If closed reduction is unsuccessful, or if X-rays show a complex fracture or soft tissue caught within the joint, a surgical procedure known as open reduction is required. Soft tissue structures, such as the volar plate or tendons, can become trapped, physically blocking the bone from returning to its place. Surgery may also be indicated if the joint remains unstable after a successful closed reduction, often requiring the repair of torn ligaments or stabilization with Kirschner wires (K-wires).
Recovery and Rehabilitation
After the thumb joint has been successfully reduced, the primary phase of recovery involves immobilization to allow the damaged ligaments and joint capsule to heal. The thumb spica splint or cast is typically worn for three to six weeks, depending on the severity of the injury and the joint’s stability. Follow-up appointments are scheduled to monitor the healing process and ensure the alignment is maintained with periodic radiographic checks.
The patient must monitor for any signs of complications during immobilization, such as persistent or worsening pain, new numbness, or tingling, which could indicate issues like nerve compression or loss of reduction. Once the immobilization period is complete, the focus shifts to restoring function through physical or occupational therapy.
A structured rehabilitation program is necessary to regain the full range of motion and strength lost while the thumb was held still. Therapy exercises begin with gentle active range of motion and gradually progress to strengthening exercises over several weeks, with full recovery often taking several months.