Anterior Shoulder dislocation
Common injury of young people playing contact sport, may progress to recurrent episodes of symptomatic instability.
The usual treatment for a primary anterior dislocation is a short period of immobilisation followed by a programme of rehabilitation and a gradual return to full activity. In young high demand athletes with high energy traumatic dislocations, consideration could be given to primary arthroscopic stabilisation.
At present however the standard treatment remains non operative management.
Patients less than 40 (1)
30-90 % of young patients (<30 years of age) may need operative stabilization. Some shoulders with recurrent dislocation become stable over time.
This finding of
only 30 % needing surgery in a prospective 10 year follow up study throws
questions on prophylactic operative treatment, in the young first time
The same degree of arthropathy is noted in the shoulders that have had recurrent or operatively treated dislocation as those with only one dislocation. Only 10% of the shoulders having a replacement for OA are associated with recurrent dislocation.
Recurrent dislocation occurs in 0-20% of cases.
tears occur in 30-80% of cases. The persistence of significant pain or weakness
3 weeks after primary dislocation in this age group is an indication for further
investigation (arthrography or ultrasound). Beware may have been pre-existing
tear. In asymptomatic patients over 70 yrs up to 50% will have asymptomatic rotator
cuff tears and in patients over 80, 80% will have asymptomatic tears.
Several relocation methods exist.
In the UK conventional practice is intravenous sedation and manipulation in A&E.
Recently reported is an interesting technique. (Shown to be safe and as effective)
An intra-articular injection of 20 mL of 1% lidocaine, injected into the glenohumeral joint, from just off the lateral edge of the acromion, through a 20-gauge, 35-mm needle. The shoulder is then reduced by Stimsons technique, hanging the arm over the edge of the trolley with a weight on it. (6)
Popular practice is to immobilise inside shirt (internal rotation) 3 weeks then in sling outside shirt for further 3 weeks (total 4 to 6 weeks). However some studies show no difference in long term if just treat symptomatically. (1) Perhaps one of the reasons the duration of immobilization inside a sling or shirt does not affect recurrence is because with internal rotation the anterior capsule and labrum ("Bankart lesion") floats away from the glenoid. In external rotation subscapularis becomes taught and coapts the "Bankart" lesion onto the glenoid rim. As shown in an MRI study of dislocated shoulders. (7)
Nerve injury (3,4)
The prognosis of nerve lesions after dislocations of the shoulder is favourable, it is not necessary to carry out EMG routinely. In cases of paralysis or severe paresis it is essential to perform an EMG at three weeks. If, after two to three months, no electrophysiological and or clinical improvement occurs, exploration should be undertaken.
The reported prevalence of nerve injury after anterior dislocation of the shoulder ranges from 5% to 55% this tends to increase with advancing age. The more actively you look for it the higher the incidence. The most common nerve injured is the axillary nerve 42%, suprascapular nerve 14%, radial nerve 7%, musculocutaneous nerve 12%, median nerve 4%, ulna nerve 8%. The presence of normal sensation does not exclude a motor injury.
Most nerve injuries will recover near complete EMG and motor function within a period of 12 to 45 weeks. Ultimate shoulder function depends on active physiotherapy to maintain passive range of motion awaiting recovery.
Rotator cuff tears in association with anterior dislocation occurs in 30%-80% of elderly patients.
Bearing in mind in asymptomatic patients over 70 yrs up to 50% will have asymptomatic rotator cuff tears and in patients over 80, 80% will have asymptomatic tears.
In patients beyond retirement age:
If loss of abduction is due to a nerve lesion, muscle strength will recover spontaneously. If there is, in addition, a ruptured cuff, it is possible that the latter is long standing. Furthermore, the symptoms of an acute rupture often resolve spontaneously.
In young patients:
With an extensive acute tear of the rotator cuff, restoration of the normal anatomy is important. In these cases, needle electrodiagnosis is essential in order to identify additional nerve lesions.
1. Primary Anterior Dislocation of the Shoulder in
Young Patients. A Ten-Year Prospective Study . HOVELIUS, B. G. AUGUSTINI, H.
FREDIN, O. JOHANSSON, R. NORLIN, and J. THORLING
2. Anterior dislocation of the shoulder in elderly patients; S. Gumina; F. Postacchini -JBJS -B1997 (79): 540-543
3. The incidence of nerve injury in anterior dislocation of the shoulder and its influence on functional recovery - C. P. J. Visser; L. N. J. E. M. Coene; R. Brand; D. L. J. Tavy - JBJS - B 1999 (81): 679-685
4. Isolated and
combined lesions of the axillary nerve
5. C. M. Robinson,
M. Kelly, and A. E. Wakefield
6. Suzanne L.
Miller, Edmond Cleeman, Joshua Auerbach, and Evan L. Flatow
7. Eiji Itoi, Ryuji Sashi, Hiroshi Minagawa, Togo Shimizu,
Ikuko Wakabayashi, and Kozo Sato
Last updated 10/04/2005