MANUAL MINORS
A dislocation of the fifth metacarpal refers to the displacement of the base of the fifth metacarpal (the bone connecting to the pinky finger) from its articulation with the hamate bone in the wrist. This dislocation is rare and typically occurs due to direct trauma to the hand or falls onto a closed fist, causing pain, deformity, and difficulty moving the pinky finger.
Diagnosis
Diagnosis is made based on trauma history, with clinical signs of deformity, pain, and swelling on the back of the hand. X-rays are essential to confirm the dislocation and check for associated fractures.
Differential Diagnosis
Condition | Key Differences |
|---|---|
Fifth metacarpal fracture | Deformity and pain localised to the shaft or head of the bone, with a visible fracture line on X-rays. |
Carpometacarpal joint dislocation | Affects the connection between the carpal and metacarpal bones, with visible displacement on imaging studies. |
Hand ligament sprain | Pain and swelling, but no bone displacement evident on X-rays. |
Tenosynovitis | Pain and stiffness without evidence of direct trauma or dislocation on imaging studies. |
Emergency Management
Immediate immobilisation of the affected hand to prevent further damage.
Administration of analgesics and anti-inflammatories for pain management.
Closed reduction of the dislocation under local anaesthesia or sedation to realign the fifth metacarpal.
Post-reduction X-ray to confirm successful realignment.
Application of a plaster cast or immobiliser to protect the reduced joint.
Definitive Treatment
After reduction, the patient should wear a splint or cast for 3-6 weeks, depending on the stability of the reduction. If instability or ligament damage is present, surgical fixation may be required to ensure proper alignment of the metacarpal. Post-reduction rehabilitation with physical therapy is crucial for regaining mobility and hand function.
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