Abstract
Bilateral shoulder dislocations are rare, and if they occurred, posterior type of dislocations is common. Bilateral anterior shoulder dislocations are very rare and occur due to trauma with unique mechanism of injury. We report a case of unreduced simultaneous bilateral anterior dislocations of shoulder without associated fractures in a forty-year-old man following a unique mechanism of injury; both hands of the patient were pulled from either side. To the best of our knowledge, this unusual mechanism of injury has not been reported in the literature.
1. Introduction
Anterior glenohumeral dislocations are most commonly encountered major joint dislocations in emergency room. Bilateral shoulder dislocations with or without fractures are rare. For a simultaneous bilateral dislocation to occur, the forces must act synchronously on both shoulders in a similar manner. Bilateral posterior dislocations are commonly seen during electrocution, convulsions, or hypoglycemic seizures due to violent contractions of internal rotators of shoulder. There are few reported cases of bilateral anterior shoulder dislocations with different mechanisms of injury: at the start of backstroke swimming competition, bench pressing athlete, fall on elbows, postseizure episode, trying to prevent a backward fall by extending both arms behind the back, and, in our case, pulling of both hands from either side with both limbs in abduction and external rotation.
2. Case Report
A forty-year-old man presented to our hospital in December 2013 with pain and restricted range of movements in both shoulders. Patient was involved in a quarrel six weeks back and both the hands of the patient were held by two people on either side and were pulled. He had no history of seizures, previous shoulder dislocations, or laxity of other joints. On examination, arms were abducted and externally rotated. There was loss of round contour of shoulder with fullness over anterior aspect of both shoulders. No neurovascular injury and no associated fractures were confirmed by radiographs and CT scan in both arms (Figures 1 and 3). Patient was able to perform flexion up to 30 degrees and abduction and external rotation with no pain restraint. Adduction and internal rotations were restricted (Figure 1).
Old unreduced dislocations are difficult to reduce by closed methods because of soft tissue contractures, fibrous tissue in the glenoid cavity, retracted rotator cuff muscle, iatrogenic fractures, and neurovascular damage. Left shoulder was operated on six weeks back. Soft tissue release and open reduction of the head into glenoid cavity was done through deltopectoral approach and secured with k-wires (Figure 2).
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3. Discussion
Unilateral anterior shoulder dislocations account for 95% of all shoulder dislocations, but simultaneous bilateral anterior dislocations are a clinical rarity because almost always one extremity takes the brunt of impact during trauma incidence [1]. Axial loading with arm in internal rotation and adduction produces posterior dislocation, which is common in electrical shock or postseizure episode due to violent contraction of internal rotators of shoulder. Mechanism of bilateral anterior dislocation is combination of forced extension, abduction, and external rotation of both arms and these forces need to be symmetrical and simultaneous. Acute bilateral anterior dislocations have to be reduced quickly with various closed methods: the Stimson gravity method, Kocher maneuver, or Milch maneuver. Unreduced bilateral anterior dislocations cannot be reduced by closed methods because of fibrous tissue in glenoid cavity, risk of iatrogenic fractures, soft tissue interposition, and neurovascular damage.
Simultaneous bilateral anterior shoulder dislocations are rare. They have a unique mechanism of injury and were first described in 1902 in patients in whom excessive muscular contraction occurred as a result of camphor overdose by Mynter [2]. Cresswell in 1998 reported a case of bilateral anterior dislocation of the shoulder without any fractures in a bench pressing athlete [3]. Lasanianos and Mouzopoulos in 2008 reported a case of bilateral anterior dislocation of the shoulders after a seizure episode [4]. Turhan and Demirel in 2008 reported a bilateral anterior dislocation case in a horse rider [5], Felderman et al. in 2009 reported a similar case in a 44-year-old woman who was doing chin-up exercise [6], Thakur et al. reported a similar case where patient was trying to prevent a backward fall by extending both arms behind his back [7], Dlimi et al. in 2012 reported a case of bilateral anterior dislocation of the shoulders at the start of a backstroke swimming competition [8], and Yashwantha et al. in 2013 reported a similar case due to a fall over pointed elbows [9]. In our case, it was pulling of both hands on either side, with both arms in abduction and external rotation, which is a unique mechanism of injury never described in the literature (Table 1).
Conflict of Interests
The authors declare that there is no conflict of interests regarding the publication of this paper.