Finger dislocation occurs when the finger bones are no longer in their normal position. These lesions are most often the result of a sudden or inappropriate gesture, sometimes very violent, and can lead to serious consequences. The majority of finger dislocations occur at the middle joint, usually when the finger bends backwards, but they can occur at other finger joints.
What Is A Finger Dislocation?
In each of our joints, the two bone ends are not in contact but separated by an aqueous cushion, the synovial fluid, which ensures mobility without friction.
On the other hand, these ends are held together from the inside out by:
- a capsule, which allows the joint to maintain its tightness
- ligaments, which play the role of fixators
- the periarticular muscles.
Finger dislocation is characterized by the loss of contact of two articular surfaces at the level of a finger, following a violent shock which also damages the ligaments. These lesions are frequent and potentially serious because they are very stiff. There are different types: dorsal, lateral and palmar dislocations. We also speak in everyday language of “dislocations”.
They should not be confused with sprains where only one ligament is damaged and the bone ends remain in place.
Finger sprains, Finger dislocation and Jammed Finger
Finger sprains occur when the ligaments between the bones are stretched resulting in hyperextension. In case of finger sprain, ligament is partially or a complete tear. A Finger dislocation, on the other hand, happens when a finger joint is pushed out of alignment completely.
A jammed finger is an injury which is caused by injury in the joint of the middle finger resulting in difficult movement of the finger and swelling of the finger and even it bends.
Which Examinations To Detect A Finger Dislocation?
Sprains and dislocations of the fingers result from the same lesional mechanisms and are sometimes difficult to differentiate when the dislocation has spontaneously reduced. The examination of the patient is often falsely reassuring, with a simply swollen and slightly painful finger. It is therefore advisable to remain very cautious as soon as the diagnosis is mentioned and to systematically carry out a “testing” of the joint to retain a precise diagnosis of the lesion, which will determine the therapeutic approach.
The examination is sometimes difficult because of the pain and can be repeated if necessary after 48 hours of immobilization. Palpation highlights, depending on the case, anterior (palmar plate), lateral (lateral ligaments) or posterior (insertion of the median band of the extensor) pain.
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X-rays should be taken from multiple angles. Frontal and lateral X-rays look for an associated fracture and/or subluxation. It also makes it possible to highlight bone tearing and to control joint congruence. Dynamic X-rays can help assess the extent of lateral laxity. If necessary, ultrasound can assess ligament damage.
What Are Treatments For Dislocated Fingers?
To treat most dislocations, doctors inject an anesthetic into the base of the affected finger, and the bones of the finger are pushed back into place: this is called reduction. This can be done with or without surgery.
Once the joint is back in place, doctors gently move the finger in different directions to determine how badly the ligaments are affected. Generally, a splint is applied and worn for about 3 weeks. An analgesic and possibly anti-inflammatory treatment are associated, as well as an icing and a temporary cessation of sports activities.
Metacarpophalangeal dislocations of the thumb
The treatment of simple forms of dislocations is orthopedic. The reduction maneuver must be performed carefully, as described by Farabeuf, and consists of exaggerating the hyperextension of the phalanx by keeping it pressed against the joint so that it maintains intimate contact with the back of the metacarpal. It was then slid from top to bottom, maintaining pressure to push the sesamoid strap back along the back of the metacarpal. The reduction will be accompanied by a jump. The purpose of this maneuver is to bring the base of the phalanx back to its normal position, keeping it under strong pressure to avoid any interposition.
Complicated forms can correspond to a dorsal dislocation which was simple at the start and which became complicated following a bad reduction maneuver. The treatment is most often surgical, generally via the palmar approach, which allows good exposure of the buttonhole, reinsertion of the palmar plate and repair of the ligament lesion and the sesamoid apparatus.
Interphalangeal dislocations of the thumb
Once the reduction has been carried out, they are stable and allow rapid rehabilitation after a short immobilization. However, they often remain painful and tend to stiffen.
A spontaneously reduced dislocation can lead to major instability, usually the metacarpal subluxates when the thumb is flexed in the palm. The treatment is identical to that of an unreduced dislocation. The reduction is easy under anesthesia (simple traction) and must be followed at least by stabilization with a pin, or even ligamentoplasty from the outset. Careful monitoring is necessary to detect the secondary appearance of a subluxation, which would then impose the realization of a ligamentoplasty.
Dislocations of the metacarpophalangeal joints of the long fingers
Palmar dislocations are exceptional and always surgical. Dorsal dislocations, which are more frequent, require treatment in the operating room, under anesthesia. The reduction can then be carried out by external manoeuvre, by putting the wrist in flexion to relax the flexor apparatus, and the reduction must be carried out according to the Faraboeuf manoeuvre, by maintaining the phalanx firmly applied to the head of the metacarpal throughout its course of reduction.
Otherwise the complete reduction is irreducible because there is an interposition of the volar plate or intrinsic incarceration. Reduction is surgical via the palmar approach, taking great care not to injure the collateral bundles.
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After a finger dislocation, rehabilitation is essential in order not to lose the functionality of the hand and to retain its ability to grip and use. The objective of physiotherapy rehabilitation is here to:
- Fight against edema
- Maintain the tendino-periosteal slippage
- Maintain capsulo-ligament flexibility
- Fighting pain… all this without harming tissue healing!
Rehabilitation must be as early as possible in order to avoid irreversible stiffness of the finger. Various exercises are offered:
Phase 1 (D0 to D30): recovery and maintenance of range of motion
- Massages, drainages
- Immediate active mobilizations, gentle, in full flexion and extension taking into account pain and swelling
- Gentle electro-active stimulation of flexor and extensor muscles
Phase 2 (after D30): recovery of functionality
- Same exercises as before
- Active work against finger resistance
- Proprioception work
- Specific work related to the patient’s profession, sport or hobbies
- If necessary, use splints.
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