We thank Dr. Kain and colleagues for their interest and comments on our study and for reporting their study outcomes.

According to their letter,only 2 patients (7%) re-dislocated the same shoulder within the 18-month time period after being treated with an external rotation brace. This outcome is excellent and almost equivalent to the outcomes reported after surgical stabilization (1,2). We suggest that these excellent results might be a reflection of a few factors: 1) shorter period of follow-up, 2) smaller sample size, and 3) a difference in the method of immobilization compared to our study.

We performed shoulder immobilization with the arm in adduction and 10 degrees of external rotation. Recent biomechanical and clinical studies have demonstrated that external rotation in adduction may not be the best position for reduction of a Bankart lesion. According to Hart and Kelly (3),the best reduction of a Bankart lesion was achieved with the arm in 30 degrees of abduction and 60 degrees of external rotation during arthroscopic examination of shoulders after initial dislocation. Limpisvasti and colleagues measured the strain of the IGHL using cadaver shoulders in various arm positions (4). They reported that no significant difference in the strain of the IGHL was observed between intact and dislocated specimens with the arm in 30 and 45 degrees of abduction and between 0 and 60 degrees of external rotation.

These reports indicate that not keeping the shoulder in external rotation and some degree of abduction may be of further benefit for patients after first time dislocation in reducing the Bankart lesion. We do not know the details of how Dr. Kain and colleagues immobilized the shoulder, but their excellent results might have resulted from a difference in the method of immobilization. Of course, this speculation must be proven in a future study.

References

1. Jakobsen BW, Johannsen HV, Suder P, Søjbjerg JO. Primary repair versus conservative treatment of first-time traumatic anterior dislocation of the shoulder: a randomized study with 10-year follow-up. Arthroscopy. 2007;23:118-23.

2. Kirkley A, Werstine R, Ratjek A, Griffin S. Prospective randomized clinical trial comparing the effectiveness of immediate arthroscopic stabilization versus immobilization and rehabilitation in first traumatic anterior dislocations of the shoulder: long-term evaluation. Arthroscopy. 2005;21:55-63.

3. Hart WJ, Kelly CP. Arthroscopic observation of capsulolabral reduction after shoulder dislocation. J Shoulder Elbow Surg. 2005;14:134-7.

4. Limpisvasti O, Yang BY, Hosseinzadeh P, Leba TB, Tibone JE, Lee TQ. The effect of glenohumeral position on the shoulder after traumatic anterior dislocation. Am J Sports Med. 2008;36:775-80.

To the Editor:

From the preliminary findings reported by Itoi et al.(1), we established a protocol for immobilizing patients in an external rotation brace following a first time anterior shoulder dislocation. According to the protocol, patients had to meet the following criteria:

1. Radiographic evidence of primary shoulder dislocation, excluding subluxation

2. Under the age of 30 years

3. Deemed to be compliant with the treatment for 3 weeks

Those who met the criteria had the external rotation brace applied on their first visit to the fracture clinic. They retained the brace for 3 weeks, after which for a further 2 weeks, they used a broad arm sling coming out of it only for physiotherapy.

From April 2006 to October 2007, 29 patients who presented with first time anterior shoulder dislocations and who met the inclusion criteria were treated with the external rotation brace. Of these, 2 (7%) patients re-dislocated the same shoulder within the 18 month time period. Our re-dislocation rate is less than that reported by Itoi et al., who found a 26% recurrence rate in the external rotation base group at a minimum follow up of two years (2). Importantly, our findings using the external rotation brace method compare favorably with previous studies in which immobilization in internal rotation was used for treating primary anterior shoulder dislocations (3-7).

The authors did not receive any outside funding or grants in support of their research for or preparation of this work. Neither they nor a member of their immediate families received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which the authors, or a member of their immediate families, are affiliated or associated.

References

1. Itoi E, Hatakeyama Y, Kido T, Sato T, Minagawa H, Wakabayashi I, Kobayashi M. A new method of immobilization after traumatic anterior dislocation of the shoulder: a preliminary study. J Shoulder Elbow Surg. 2003;12:413-5.

2. Itoi E, Hatakeyama Y, Sato T, Kido T, Minegawa H, Yamamoto N, Wakabayashi I, Nozaka K. Immobilization in external rotation after shoulder dislocation reduces the risk of recurrence. A randomized controlled trial. J Bone Joint Surg Am. 2007;89:2124-31.

3. Hovelius L, Augustini BG, Fredin H, Johansson O, Norlin R, Thorling J. Primary anterior dislocation of the shoulder in young patients. A ten-year prospective study. J Bone Joint Surg Am. 1996;78:1677-84.

4. Kralinger FS, Golser K, Wischatta R, Wambacher M, Sperner G. Predicting recurrence after primary anterior shoulder dislocation. Am J Sports Med. 2002;30:116-20.

5. Rowe CR, Sakellarides HT. Factors related to recurrences of anterior dislocations of the shoulder. Clin Orthop. 1961;20:40-8.

6. Ryf C, Matter P. [The initial traumatic shoulder dislocation. Prospective study]. Z Unfallchir Versicherungsmed. 1993;Suppl 1:204-12. German.

7. Simonet WT, Cofield RH. Prognosis in anterior shoulder dislocation. Am J Sports Med. 1984;12:19-24.