Review Question - QID 214621

The patient has sustained a right anterior glenohumeral dislocation without a history of prior shoulder instability. On the basis of his lack of weakness, he is unlikely to have sustained a rotator cuff tear. He has completed 1 week of immobilization and he may safely discontinue immobilization at this time without increasing his risk of recurrent shoulder instability.

The rehabilitation and length of immobilization following a primary traumatic anterior glenohumeral dislocation has been very controversial. Age, prior injuries and concurrent bony and soft tissue injuries all play a factor in determining a patient's likelihood for repeat instability. In general, studies have shown that patients less than age 30 are at a higher risk of recurrent dislocation. More recent studies have refuted evidence of any added benefit of additional immobilization greater than 1 week in preventing recurrent instability. Furthermore, the position of immobilization has been discussed extensively [neutral vs. internal rotation (IR) vs. external rotation (ER)] with various results. Most meta-analyses and randomized trials have not shown a benefit in reducing recurrent instability depending on shoulder position but a few studies have discussed a benefit in ER immobilization in younger patients (age < 40).

Paterson et al. performed a systematic review of 6 level I/II studies to determine if duration of immobilization played a role in preventing recurrent dislocation in patients with anterior glenohumeral dislocations. They noted that the rate of recurrent instability was 41% in patients who had been immobilized for one week or less and 37% in patients who had been immobilized for three weeks or longer. They noted that age less than 30 at the time of the index dislocation was significantly predictive of recurrence in most studies. The authors concluded that there is no benefit of conventional sling immobilization for longer than one week for the treatment of primary anterior shoulder dislocation and an age < 30 thirty years at the time of injury is significantly predictive of recurrence.

Hovelius et al. performed a twenty-five years followup study in 229 patients who underwent non-operative management after primary anterior shoulder glenohumeral dislocation. They noted that 43% of the shoulders had not re-dislocated, 15% had re-dislocated but had become stable over time, and 27% had undergone surgery for the treatment of recurrent instability. They noted that the length of immobilization after the primary dislocation did not change the prognosis. The authors concluded that after twenty-five years, half of the primary anterior shoulder dislocations that had been treated nonoperatively in patients with an age of 12-25 years had not recurred or had become stable over time.

Liavaag et al. performed a randomized trial to compare immobilization in IR versus ER in 158 patients with a primary traumatic anterior glenohumeral dislocation. Patients were randomly assigned to treatment with immobilization in either IR (95 patients) or ER (93 patients) for three weeks and a 2-year follow-up was obtained on 98% of the patients. The authors noted that the recurrence rate was 24.7% in the IR group and 30.8% in the ER group (p = 0.36). The authors concluded that immobilization in ER does not reduce the rate of recurrence for patients with first-time traumatic anterior shoulder dislocation.

Figures A and B are the scapular Y and AP radiographs revealing an anterior glenohumeral dislocation.

Incorrect Answers:
Answer 1, 3, 4: The patient will not decrease his risk of recurrent instability by further immobilization, regardless of the position of immobilization. There are studies that discuss immobilization in ER reduces the risk of recurrent instability, but this is mainly in the younger cohort (age < 40).
Answer 5: Patients < age 30 are at an increased likelihood of repeat dislocation.