Surgical Anatomy: The articulations between metacarpal bones and proximal row of phalanges are condyloid, permitting flexion, extension, adduction, abduction, and circumduction. These joints allow a variable amount of hyperextension and are held together by two lateral and one ventral ligament; the posterior ligament's role is taken by the extensor tendon crossing the articulation. Interphalangeal articulations are hinge joints allowing only flexion and extension. Metacarpo-phalangeal joints of the thumb and forefinger are more prone to dislocation than those of middle, ring, and little fingers.
Diagnosis: Recognition is easy as patients often diagnose themselves before seeing a surgeon; however, complicating fractures can be overlooked.
Symptoms: The injured finger loses function immediately with severe pain. Deformity varies according to the nature and direction of dislocation.
Treatment: In simple cases, reduction should be immediate. For compound luxations, wounds must be cleaned before displacement correction. Manipulations vary based on type of displacement; traction and counter-traction may not suffice in complete luxation with overriding deformity.
Operative Treatment: Indicated for compound cases or when tissue prevents manipulation-based reduction. Wounds must be thoroughly cleansed and irrigated to prevent infection leading to adhesions within joints.
After-Treatment: Injured articulation should rest initially, followed by early passive motion to restore function. Flexion and extension periods are repeated until after-treatment is complete; healing of torn ligaments should allow guarded use of the injured finger in two weeks.
Prognosis: Complete restoration of function with proper treatment in simple cases; compound cases may result in stiff fingers or amputation if severe infection occurs. <Callout type="important" title="Critical Ligament Tearing">In backward luxations, the anterior ligament is usually torn away from the metacarpal bone and can become interposed between bones, offering resistance to reduction.</Callout>
Key Takeaways
- Metacarpo-phalangeal joints of the thumb and forefinger are more prone to dislocation.
- Recognition of luxations is often self-diagnosed by patients.
- Wounds in compound cases must be cleaned before displacement correction.
Practical Tips
- Ensure thorough cleaning and irrigation of wounds in compound luxations.
- Use traction and counter-traction for simple luxation corrections.
- Early passive motion after reduction is crucial to restore finger function.
Warnings & Risks
- Complicating fractures can be overlooked during diagnosis.
- Infection following a compound luxation may result in permanent stiffness or loss of joint mobility.
Modern Application
While the surgical techniques described here are outdated, understanding the anatomy and principles of dislocation treatment remains crucial. Modern medical practices have advanced sterilization methods and antibiotics to prevent infection, but the importance of proper wound care and early motion exercises still applies.
Frequently Asked Questions
Q: What types of ligaments hold finger joints together?
Finger joints are held together by two lateral and one ventral ligament. The posterior ligament's role is taken by the extensor tendon crossing the articulation.
Q: Why is early passive motion important after dislocation treatment?
Early passive motion helps break up forming adhesions within joints, reducing the chances of these adhesions reforming and ensuring the subsequent restoration of finger function.
Q: What should be done before correcting displacement in compound luxations?
Before correcting displacement in compound luxations, wounds must be thoroughly cleaned and irrigated to prevent infection leading to adhesions within joints.