Treatment of Traumatic Dislocations.
Last updated Thursday, February 10, 2005
Acute traumatic anterior dislocations
Acute dislocations of the glenohumeral joint should be reduced as
gently and expeditiously as possible, ideally after a complete set of
radiographs is obtained to rule out associated bony injuries.Timing of reduction and analgesia Early relocation promptly eliminates the stretch and compression of
neurovascular structures, minimizes the amount of muscle spasm that
must be overcome to effect reduction, and prevents progressive
enlargement of the humeral head defect in locked dislocations. The
extent of anesthesia required to accomplish a gentle reduction depends
on many factors, including the amount of trauma that produced the
dislocation, the duration of the dislocation, the number of previous
dislocations, whether the dislocation is locked, and to what extent the
patient can voluntarily relax the shoulder musculature. When seen
acutely, some dislocations can be reduced without the use of
medication. At the other extreme, reduction of a long-standing, locked
dislocation may require a brachial plexus block or general anesthetic
with muscle relaxation. Many practitioners use narcotics and muscle
relaxants to aid in the reduction of shoulder dislocations. A potential
trap exists: the dosages required to produce muscle relaxation while
the shoulder is dislocated may be sufficient to produce respiratory
depression once the shoulder is reduced. Our recommendation is that if
these medications are to be used, they should be administered through
an established intravenous line. This produces a more rapid onset, a
short duration of action, and the opportunity to adjust the required
dose more appropriately. Furthermore, resuscitation (if necessary) is
facilitated by the prospective presence of such a route of access.
Airway management tools should be readily available.
Lippitt et al (Lippitt et al, 1991; Lippitt et al, 1992) compared
two methods of analgesia for the reduction of anterior dislocations:
(1) intravenous analgesia and muscle relaxation and (2) intraarticular
lidocaine. With respect to the first, they found a 75% success rate and
a 37% complication rate in a retrospective series of 52 reductions in
which intravenous narcotics (morphine (3-24 mg) or meperidine (12.5 -
100 mg) with or without diazepam (1.5 - 15 mg) or midazolam (1 - 10
mg)) were used for analgesia. They remarked on the difficulty of
determining the appropriate intravenous dose of narcotics. Level of
pain, age, smoking history, alcohol consumption, cardiac disease and
regional perfusion are just a few of the factors which may influence
the narcotic requirement (Bailey and Stanley, 1986). Older patients and
intoxicated patients are more sensitive to the respiratory depressant
effects of narcotics. Because pain counteracts the respiratory
depressant effects, patients sedated by narcotics are at increased risk
of respiratory depression after removal of the painful stimulus when
the shoulder is reduced. Complications from intravenous analgesia
included respiratory depression, hypotension, hyperemesis, and
oversedation. With respect to the second method using 20 cc of 1% plain
intraarticular lidocaine, Lippitt et al found a 100% success rate in
the reduction of 40 dislocations with no complications. One patient
inadvertently received 400 mg instead of 200 mg of lidocaine and
developed transient tinnitus, perioral numbness, and mild dysarthria. A
survey revealed that both the patients and the physicians were
satisfied with this method. The authors speculated that the success of
the intraarticular injection may be due to a combination of pain relief
allowing reduction, relief from muscle spasm and venting of the joint. Method of reduction Once the shoulder is relaxed, a variety of gentle methods can be
used to achieve reduction. Gentle traction on the arm is common to
most. One such method is known as the Stimson technique. Although named
for Lewis A. Stimson (Stimson, 1900; Stimson, 1912) of New York City,
Stimson credited a Dr. Cole, a house-staff physician of the Chambers
Street Hospital. In the Stimson method, the patient is placed prone on
the edge of the examining table while downward traction is gently
applied. (Stimson, 1900) The traction force may be applied by the
weight of the arm, by weights taped to the wrist, or by the surgeon. It
may take several minutes for the traction to produce muscle relaxation.
It is important that patients not be left unattended in this position,
particularly if narcotics and muscle relaxants have been administered.
Analgesia While analgesia may not be necessary to achieve reduction, we are
impressed with the safety and effectiveness of intraarticular lidocaine
as described by Lippitt et al. (Lippitt, Kennedy and Thompson, 1991;
Lippitt, Kennedy and Thompson, 1992) In this method a maximum 20 cc of
1% plain lidocaine is injected using an 18 gauge needle placed two
centimeters below the lateral edge of the acromion just posterior to
the dislocated humeral head and directed towards the glenoid fossa. The
amount of lidocaine is limited to 200 mg. (Savarsee and Covino, 1986)
Placement of the needle in the joint is confirmed by a combination of
(1) feeling the needle penetrate the glenohumeral capsule, (2)
aspirating joint fluid/hemarthrosis and assuring that the injection is
not intravascular, (3) gently palpating the glenoid fossa with the
needle, and (4) verifying easy flow on injection and return of the
injected lidocaine solution. Fifteen minutes are allowed to maximize
the analgesic effect of the lidocaine prior to manipulation.
Maneuver Reduction of either anterior or posterior glenohumeral dislocations
usually can be effected by traction on the abducted and flexed arm with
counter traction on the body. The patient is placed supine with a sheet
around the thorax, with the loose ends on the side opposite the
shoulder dislocation where they are held by an assistant. The surgeon
stands on the side of the dislocated shoulder near the waist of the
patient. The elbow of the dislocated shoulder is flexed to 90 degrees
(to relax the neurovascular structures) and traction applied through a
sheet looped over the patient's forearm or traction can be applied
directly. Steady traction along the axis of the arm will usually effect
reduction. To this basic maneuver, one may add gentle rocking of the
humerus from internal to external rotation or outward pressure on the
proximal humerus from the axilla. These additions are particularly
useful if prereduction axillary roentgenograms show the humeral head to
be impaled on the glenoid rim. Postreduction roentgenograms are used to
confirm reduction and to detect fractures. A postreduction
neurovascular check is routine.
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