Dislocated finger

Dislocated fingers are a common hand injury that can result from trauma, sports injuries, or falls. They often cause pain, swelling, and deformity, potentially impairing hand function if not promptly treated. Understanding the anatomy and mechanisms of injury is essential for proper diagnosis and management.

Anatomy of the Finger

Bones

The fingers are composed of phalanges arranged in three segments: proximal, middle, and distal. Each finger contains three phalanges, except for the thumb, which has two. The joints connecting these bones are the metacarpophalangeal (MCP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints, which allow complex movements of the hand.

Ligaments and Tendons

• Collateral ligaments: Stabilize the sides of the finger joints and prevent excessive lateral movement.
• Volar plate: Thick fibrocartilage on the palmar aspect of PIP and MCP joints that prevents hyperextension.
• Extensor and flexor tendons: Flexor tendons run along the palmar side allowing finger flexion, while extensor tendons on the dorsal side facilitate extension.

Neurovascular Structures

• Digital nerves: Provide sensory innervation to the palmar and dorsal aspects of the fingers.
• Digital arteries: Supply blood to the phalanges, joints, and surrounding soft tissues.

Etiology

Traumatic Causes

• Direct impact or blow to the finger during sports or accidents
• Falls on an outstretched hand causing forceful hyperextension or lateral stress
• Crush injuries from machinery or heavy objects

Other Causes

• Congenital joint laxity, predisposing the finger to dislocation even with minor trauma
• History of previous dislocations or ligamentous injuries increasing susceptibility to recurrent dislocations

Pathophysiology

Finger dislocations occur when the articulating surfaces of the phalanges are forcibly displaced from their normal alignment. This displacement often involves tearing or stretching of the surrounding ligaments, joint capsule, and volar plate. The type and direction of dislocation are determined by the mechanism of injury, commonly classified as dorsal, volar, or lateral dislocations. Associated soft tissue damage, including tendon or neurovascular injury, can complicate the clinical course.

Clinical Presentation

Symptoms

• Acute pain localized to the affected joint
• Swelling and bruising over the finger
• Visible deformity or abnormal angulation of the finger
• Loss of normal joint function, including inability to flex or extend the finger

Signs

• Palpable misalignment of the joint
• Tenderness on palpation of the joint and surrounding ligaments
• Instability of the finger joint
• Possible neurovascular compromise, including numbness, tingling, or reduced capillary refill

Diagnosis

History and Physical Examination

Diagnosis of a dislocated finger begins with a detailed history of the injury, including the mechanism, timing, and any previous dislocations. Physical examination focuses on inspecting for deformity, swelling, bruising, and joint instability. Palpation helps identify the displaced phalange and assess tenderness. Neurovascular status should be carefully evaluated by checking capillary refill, pulse, and sensation in the distal finger.

Imaging

• X-ray: Standard anteroposterior, lateral, and oblique views are used to confirm the dislocation and rule out associated fractures.
• CT scan or MRI: Employed in complex, recurrent, or irreducible dislocations to assess ligamentous injury and soft tissue involvement.

Management

Initial Care

• Immobilization with a splint or buddy taping to stabilize the joint before reduction.
• Pain management using analgesics and anti-inflammatory medications.
• Monitoring neurovascular status to ensure adequate blood flow and nerve function.

Reduction Techniques

• Closed reduction: Manual manipulation under local or digital block anesthesia to realign the joint without surgery.
• Open reduction: Surgical intervention required for complex, irreducible, or recurrent dislocations, often involving repair of torn ligaments or volar plate.

Post-Reduction Care

• Immobilization of the joint using a splint for 2–4 weeks, depending on the severity and location of the dislocation.
• Early initiation of physiotherapy and range of motion exercises after immobilization to prevent stiffness and maintain joint function.
• Regular follow-up to monitor healing, detect recurrent dislocations, and assess for any complications such as malalignment or joint instability.

Complications

• Joint stiffness: Reduced range of motion due to prolonged immobilization or inadequate rehabilitation.
• Chronic instability: Persistent looseness of the joint from ligamentous injury.
• Osteoarthritis: Degenerative changes in the joint due to repeated trauma or poor reduction.
• Neurovascular injury: Damage to digital nerves or arteries during dislocation or reduction.
• Fracture-dislocation or malunion: Associated fractures can complicate healing and result in deformity.

Prognosis

The prognosis of a dislocated finger largely depends on the severity of the dislocation, promptness of treatment, and the presence of associated injuries. Simple, isolated dislocations treated early generally have an excellent prognosis with full recovery of function. Complicated dislocations, especially those involving fractures or neurovascular injury, may have a prolonged recovery period and a higher risk of long-term complications such as stiffness or recurrent dislocations.

• Early and appropriate reduction improves functional outcomes and minimizes joint stiffness.
• Physical therapy and gradual mobilization help restore strength, range of motion, and dexterity.
• Delayed treatment or inadequate reduction increases the likelihood of chronic instability and degenerative changes.

References

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