Orthopedics

Feature Article 

Effectiveness of External Rotation Immobilization in Highly Active Young Men With Traumatic Primary Anterior Shoulder Dislocation or Subluxation

Yoshitaka Tanaka, MD; Kenji Okamura, MD, PhD; Tomohito Imai, MD, PhD

  • Orthopedics. 2010;33(9)
  • Posted September 1, 2010

Abstract

We treated 15 highly active young men (16 shoulders) with traumatic primary anterior shoulder dislocation or subluxation using 3-week external rotation immobilization. Fourteen patients (14 shoulders) were members of the Self-Defense Force and the other patient (2 shoulders) was a high school student who played club-level rugby. Average patient age at the time of the primary injury was 21.3 years (range, 17-26 years). Magnetic resonance imaging (MRI) was performed on 14 of 16 shoulders after the 3-week external rotation immobilization and showed that the anteroinferior labrum was reduced on the glenoid rim in 11 shoulders but remained medially displaced on the glenoid neck in 3 shoulders. Five shoulders, including these 3 shoulders, underwent arthroscopic Bankart repair after 3-week external rotation immobilization. Eleven shoulders continued nonoperative treatment after the immobilization. Four of 11 shoulders had no recurrence of symptoms for >2 years, and these patients were able to return to their preinjury activities. However, 7 shoulders experienced recurrence within 2 years.

We concluded that external rotation immobilization may not be as effective as mentioned previously in highly active young men with primary traumatic anterior shoulder dislocation or subluxation. Whether a patient has instability symptom recurrence after external rotation immobilization depends on more than the fact that the anteroinferior labrum is not reduced on MRI.

Primary anterior shoulder dislocation is reportedly associated with a high rate of recurrence in young patients, especially in highly active men.1-5 Therefore, some clinicians suggest early arthroscopic stabilization for primary shoulder dislocation in highly active young men because this procedure significantly reduces the recurrence rate of shoulder dislocations6-9 and improves disease-specific quality of life in young patients compared with conventional internal rotation immobilization.9

Itoi et al10-12 reported that displacement of the labrum was less in externally rotated arms on magnetic resonance imaging (MRI)10; subsequently, they reported that 3-week external rotation immobilization after primary anterior shoulder dislocation displayed a lower recurrence rate than conventional internal rotation immobilization.11,12 However, the effectiveness of external rotation immobilization for highly active young men with primary shoulder dislocation or subluxation is unclear.

The purpose of this retrospective study was to report the results of 3-week external rotation immobilization in highly active young men with traumatic primary shoulder dislocation or subluxation.

From April 2004 to April 2008, we treated 22 patients (23 shoulders) with traumatic primary anterior shoulder dislocation or subluxation using 3-week immobilization in slight external rotation (10°) with a shoulder brace (Alcare, Tokyo, Japan) (Figure 1) that was always worn except during showers. Patients were instructed to protect against internal rotation when they removed their braces to shower. Treatment after primary shoulder dislocation or subluxation was initiated after informed consent was provided by our patients.

We provided each of them information about the results of the following treatments based on previous reports: internal rotation immobilization, external rotation immobilization, and early arthroscopic Bankart repair.1-9,11,12 Each patient was informed that the recurrence rate of internal rotation immobilization was 50% to 90%, while that of early arthroscopic Bankart repair was <15%. Until December 2007, we told our patients that the recurrence rate of external rotation immobilization was 0%.13 However, after the latest report by Itoi et al,11 we told them that it was >30% in young patients.

Patients were allowed to select their treatments, and all of them initially selected external rotation immobilization. No patients had a history of any symptoms in the affected shoulder before the primary injury. Twenty patients (21 shoulders) were able to continue the 3-week external rotation immobilization as instructed. Two patients (2 shoulders) removed the brace by themselves within 2 weeks.

Of the 20 patients who were able to continue…

Abstract

We treated 15 highly active young men (16 shoulders) with traumatic primary anterior shoulder dislocation or subluxation using 3-week external rotation immobilization. Fourteen patients (14 shoulders) were members of the Self-Defense Force and the other patient (2 shoulders) was a high school student who played club-level rugby. Average patient age at the time of the primary injury was 21.3 years (range, 17-26 years). Magnetic resonance imaging (MRI) was performed on 14 of 16 shoulders after the 3-week external rotation immobilization and showed that the anteroinferior labrum was reduced on the glenoid rim in 11 shoulders but remained medially displaced on the glenoid neck in 3 shoulders. Five shoulders, including these 3 shoulders, underwent arthroscopic Bankart repair after 3-week external rotation immobilization. Eleven shoulders continued nonoperative treatment after the immobilization. Four of 11 shoulders had no recurrence of symptoms for >2 years, and these patients were able to return to their preinjury activities. However, 7 shoulders experienced recurrence within 2 years.

We concluded that external rotation immobilization may not be as effective as mentioned previously in highly active young men with primary traumatic anterior shoulder dislocation or subluxation. Whether a patient has instability symptom recurrence after external rotation immobilization depends on more than the fact that the anteroinferior labrum is not reduced on MRI.

Primary anterior shoulder dislocation is reportedly associated with a high rate of recurrence in young patients, especially in highly active men.1-5 Therefore, some clinicians suggest early arthroscopic stabilization for primary shoulder dislocation in highly active young men because this procedure significantly reduces the recurrence rate of shoulder dislocations6-9 and improves disease-specific quality of life in young patients compared with conventional internal rotation immobilization.9

Itoi et al10-12 reported that displacement of the labrum was less in externally rotated arms on magnetic resonance imaging (MRI)10; subsequently, they reported that 3-week external rotation immobilization after primary anterior shoulder dislocation displayed a lower recurrence rate than conventional internal rotation immobilization.11,12 However, the effectiveness of external rotation immobilization for highly active young men with primary shoulder dislocation or subluxation is unclear.

The purpose of this retrospective study was to report the results of 3-week external rotation immobilization in highly active young men with traumatic primary shoulder dislocation or subluxation.

Materials and Methods

From April 2004 to April 2008, we treated 22 patients (23 shoulders) with traumatic primary anterior shoulder dislocation or subluxation using 3-week immobilization in slight external rotation (10°) with a shoulder brace (Alcare, Tokyo, Japan) (Figure 1) that was always worn except during showers. Patients were instructed to protect against internal rotation when they removed their braces to shower. Treatment after primary shoulder dislocation or subluxation was initiated after informed consent was provided by our patients.

Figure 1: Immobilization in external rotation
Figure 1: Immobilization in external rotation (10°).

We provided each of them information about the results of the following treatments based on previous reports: internal rotation immobilization, external rotation immobilization, and early arthroscopic Bankart repair.1-9,11,12 Each patient was informed that the recurrence rate of internal rotation immobilization was 50% to 90%, while that of early arthroscopic Bankart repair was <15%. Until December 2007, we told our patients that the recurrence rate of external rotation immobilization was 0%.13 However, after the latest report by Itoi et al,11 we told them that it was >30% in young patients.

Patients were allowed to select their treatments, and all of them initially selected external rotation immobilization. No patients had a history of any symptoms in the affected shoulder before the primary injury. Twenty patients (21 shoulders) were able to continue the 3-week external rotation immobilization as instructed. Two patients (2 shoulders) removed the brace by themselves within 2 weeks.

Of the 20 patients who were able to continue the 3-week external rotation immobilization, we enrolled 15 patients (16 shoulders) based on the following inclusion criteria: (1) male sex; (2) age younger than 30 years at time of initial dislocation or subluxation; and (3) engagement in high-risk sports activities (Table). Fourteen patients (14 shoulders) were members of the Self-Defense Force. Participants must complete martial arts and military field training and pass a yearly strength test including push-ups, chin-ups, and softball throwing. Therefore, they had high-demand activity levels. The other patient was a high school student who played club-level rugby and had completed 3-week external rotation immobilization of both shoulders.

Table: Patient Demographics

Average patient age at the time of primary injury was 21.3 years (range, 17-26 years). Ten patients (11 shoulders) with traumatic primary anterior shoulder dislocation were diagnosed by radiograph in our institution or other institutions; 9 shoulders (8 patients) were reduced manually by an author (Y.T., T.I.), and 2 shoulders (2 patients) were reduced manually by another doctor at an outside institution. Five patients (5 shoulders) were diagnosed with traumatic primary anterior shoulder subluxation at their initial visit to our institution; MRI showed that their shoulders had joint fluid, which was considered hematoma that interposed between the anteroinferior labrum and the subcondral cortex, indicating the anteroinferior labrum tear. Therefore, these shoulders were not subjected to additional invasive examination such as magnetic resonance arthrography, although its sensitivity and specificity is higher than MRI for labral pathologies.

None of the shoulders had concomitant injuries, such as fracture of the greater tuberosity or a rotator cuff tear. A small avulsion fracture fragment of the anterior inferior glenoid bone was observed on radiograph in only 1 patient; however, we were not able to evaluate erosion or microfracture of this area because 3-dimensional reconstruction of computed tomography (CT) was not performed in this study. No patients had multidirectional shoulder instability. The average time interval between the primary dislocation or subluxation and external rotation immobilization was 1.3 days (range, 0-3 days). After the 3-week external rotation immobilization, patients were allowed to gradually participate in passive and active-assisted range of motion (ROM) exercises of the shoulder as tolerated. Exercises to strengthen the rotator muscles and stabilize the scapula were started at 4 weeks postinjury. Unlimited performance of activities of daily living was allowed at 6 weeks. Non-contact sports and overhead throwing were permitted at 2 to 3 months. Contact sports were permitted at 4 to 5 months.

Recurrence was defined as either a subjective sense of subluxation or objective documentation of dislocation after external rotation immobilization. We performed arthroscopic Bankart repair for patients with recurrence when they required surgical treatment.

During surgery, a standard posterior portal was established and arthroscopic diagnosis was performed. Presence of the labrum lesion was confirmed at arthroscopy. A Bankart lesion was identified when the anteroinferior labrum was detached from the glenoid rim. Mobilization of the anterior capsulolabral tissue was performed with a rasp or a motorized shaver. The glenoid neck was also decorticated with a burr. The first anchor was placed at the 5 o’clock position in the right shoulder. The anchors were placed approximately 5 mm on the glenoid rim. The sutures from the anchor were then placed in an inferior and lateral position through the capsulolabral tissue to shift the capsulolabral tissue superiorly and medially. Bankart lesions were routinely repaired with 3 or 4 absorbable anchors (Panalok; DePuy Mitek, Raynham, Massachusetts). When type 2 superior labrum anterior posterior (SLAP) lesions occurred with Bankart lesions, 1 or 2 anchors were added for the SLAP lesion repair.

Postoperatively, patients wore a shoulder immobilizer for 2 weeks and then started passive and active-assisted ROM exercises. The rehabilitation program that followed was the same as that after external rotation immobilization.

Results

Magnetic resonance imaging was performed on 14 shoulders after 3-week external rotation immobilization. In 3 of 14 shoulders, MRI showed that the anteroinferior labrum remained displaced from the glenoid rim and that it existed on the glenoid neck (Figure 2A). We judged that external rotation immobilization was not effective for them and suggested early arthroscopic Bankart repair. Subsequently, these patients required surgical treatment before they experienced recurrence and underwent arthroscopic Bankart repair 2 to 6 months after the primary injury. Each patient had a positive apprehension test and a positive relocation test on preoperative examination.

Figure 2A: The anteroinferior labrum remained medially displaced from the glenoid rim Figure 2B: The anteroinferior labrum remained detached from the glenoid rim
Figure 2: MRIs after 3-week external rotation immobilization. The anteroinferior labrum (white arrow) remained medially displaced from the glenoid rim and on the glenoid neck (A). The anteroinferior labrum (white arrow) remained detached from the glenoid rim but on the glenoid rim without displacement (B).

In 11 of 14 shoulders, MRI showed that the anteroinferior labrum was on the glenoid rim without displacement (Figure 2B). However, 2 patients changed from conservative treatment to surgical treatment after conclusion of the 3-week external rotation immobilization. Each patient had initially selected external rotation immobilization. However, they felt uneasy about the immobilization treatment and required surgical treatment since the results of previous reports indicated that it was a more reliable treatment to avoid recurrence than external rotation immobilization. Therefore, we performed arthroscopic Bankart repair for 2 months after their primary injuries. Each patient had a positive apprehension test and a positive relocation test on preoperative examination. Bankart lesions were diagnosed at arthroscopy in all 5 patients who underwent early arthroscopic Bankart repair. Type 2 SLAP lesions occurred in 2 patients as well; however, no capsular tears or humeral avulsions of the glenohumeral ligaments were noted. Postoperatively, all 5 patients were able to return to their preinjury activities without any symptoms of anterior instability.

Finally, 11 of 16 shoulders continued conservative treatment after the 3-week external rotation immobilization. Of these 11 shoulders, 4 did not experience recurrence for >2 years, and these patients were able to return to their preinjury activities. One of these 4 patients had a small avulsion fracture fragment of the anterior inferior glenoid bone. The other 7 shoulders experienced recurrence within 2 years. The average time interval between the primary injury and recurrence was 14.5 months (range, 6-24 months). The causes of recurrence were as follows: tackle during rugby (2 shoulders); falls during walking or skiing (3 shoulders); and throwing (2 shoulders). Five of the 7 shoulders experiencing recurrence initially had no symptoms of anterior instability after external rotation immobilization, and these patients were able to return to their preinjury activities until they experienced recurrence. The other 2 shoulders had already experienced symptoms of anterior instability of the shoulder after external rotation immobilization, and these patients had not been able to return to their preinjury activities prior to resubluxation. Four of 7 shoulders underwent arthroscopic Bankart repair after experiencing recurrence.

Discussion

We performed external rotation immobilization in highly active young men with primary traumatic anterior shoulder dislocation or subluxation after April 2004, since this method was reported to be effective in reducing the rate of recurrence after primary shoulder dislocation.11 However, in our study, recurrence occurred in 7 of 11 shoulders. Moreover, we judged external rotation immobilization as ineffective in 3 of 5 shoulders that underwent arthroscopic Bankart repair after 3-week external rotation immobilization despite the fact that they did not experience recurrence, since MRI after the immobilization showed that the anteroinferior labrum remained displaced from the glenoid rim. Therefore, we considered external rotation immobilization an ineffective method for highly active young men as previously mentioned.

Itoi et al12 compared conventional internal rotation immobilization with their new external rotation immobilization method for patients with primary shoulder dislocation in a randomized study. Of patients who were 30 years or younger, 18 of 56 (32.2%) developed recurrent instability in the external rotation group and 25 of 42 (60%) developed recurrent instability in the internal rotation group. Therefore, external rotation immobilization was deemed beneficial for patients who were 30 years or younger to reduce the risk of recurrence compared with that associated with conventional internal rotation immobilization. The results of external rotation immobilization for young patients in our study were poorer than those in the report of Itoi et al.12 We considered that this was because young women tend to not participate in collision or contact sports, and men who did not participate in such activities were excluded from our study, unlike the Itoi et al12 study.

The cause of the poor result in our study may be that immobilization was performed in slight external rotation. Itoi et al10 reported that displacement of the labrum was less with the arm in external rotation on MRI and the mean external rotation angle was 35°. Miller et al14 showed that contact force between the glenoid labrum and glenoid rim increased as the arm passed through neutral rotation and reached maximum external rotation of 45°. Given these reports, we thought that patients should be immobilized close to the maximum external rotation, but compliance was difficult since this position puts substantial strain on the patient. Patients were thus immobilized in slight (10°) external rotation as described by Itoi et al11 (Figure 1). Therefore, slight external rotation might be insufficient to reduce the anteroinferior labrum to a suitable position on the glenoid rim.

The anteroinferior labrum remained medially displaced on the glenoid neck on MRI after 3-week external rotation immobilization in 3 shoulders in our study. However, in our study, recurrence occurred in 5 of 11 shoulders, although their anteroinferior labrums had been on the glenoid rim without displacement on MRI after 3-week external rotation immobilization. Only Bankart lesions were insufficient to cause anterior dislocation of the shoulder13; therefore, we suspect that the position of the anteroinferior labrum on MRI after external rotation immobilization may not correlate with the external rotation immobilization results in highly active young men.

Because of low sample size in this study, we were unable to clarify the differences between the 4 shoulders without recurrence and the 5 shoulders with recurrence despite MRI of these 9 shoulders showing that the anteroinferior labrum was on the glenoid rim without displacement. Capsuloligamentous structures such as the anterior band of the inferior glenohumeral ligament have been thought to have an important function in stabilizing the shoulder.15,16 A large bony defect including >21% of the glenoid fossa may cause shoulder instability.17 Muscle strength and neuromuscular control were thought to affect functional stability of the shoulder.18 Therefore, studies that include a larger number of patients to clarify which of these factors relate to the failure of external rotation immobilization are required.

Our study has some limitations. The number of patients was small, the follow-up period was short, and it lacked objective and patient-rated outcome measures. Also, the study was retrospective and the patient selection criteria were criticized. Patients selected their treatment themselves based on the information we provided, and not all of the patients in our institution selected external rotation immobilization. Moreover, we discontinued conservative treatment and performed early arthroscopic Bankart repair after 3-week external rotation immobilization in 5 patients although they did not experience recurrence. Some clinicians suggest early arthroscopic stabilization for primary shoulder dislocation in young athletes because this procedure significantly reduces the recurrence rate.6-9 Comparing the external rotation immobilization results of Itoi et al12 with the results of early arthroscopic Bankart repair in their report, we judged external rotation immobilization not as effective as early arthroscopic Bankart repair to prevent recurrent instability in highly active young men with primary shoulder dislocation or subluxation.

Most of our patients were members of the Self-Defense Force who were required to return to their preinjury activities as soon as possible without recurrence. Therefore, we performed early arthroscopic Bankart repair when patients required it, regardless of the presence of instability symptoms after 3-week external rotation immobilization. However, some clinicians consider that the indication for surgery should be based on patients’ chief complaint of instability and not on imaging or patients’ requirements. Therefore, we suspect that our principle may be criticized, and it makes evidence of this study low because of some bias. Despite these limitations, we believe that this study provides clinicians with useful information when performing external rotation immobilization on highly active young men with primary traumatic anterior shoulder dislocation or subluxation.

References

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Authors

Drs Tanaka and Imai are from the Department of Orthopedic Surgery, Japan Self Defense Force, Sapporo General Hospital, and Dr Okamura is from the Department of Orthopedic Surgery, Hitsujigaoka Hospital, Sapporo, Japan.

Drs Tanaka, Okamura, and Imai have no relevant financial relationships to disclose.

Correspondence should be addressed to: Yoshitaka Tanaka, MD, Department of Orthopedic Surgery, Japan Self Defense Force, Sapporo General Hospital, Hiragishi 1-12-1-32, Toyohira-ku, Sapporo 062-8610, Japan (yoshi1869@paw.hi-ho.ne.jp).

doi: 10.3928/01477447-20100722-07

Commentary

Duong Nguyen, MD, FRCSC

The indication, timing, and method of immobilization after an acute shoulder dislocation remain topics of debate among orthopedic surgeons. Contrary to previous findings by Itoi et al, the authors of this study have shown limited success with immobilization in external rotation in young active men with a primary traumatic anterior shoulder dislocation.

Compliance issues with wearing the external rotation brace may potentially affect the true effectiveness of this treatment. There has recently been a new wave of thinking that immediate immobilization within 48 hours of the injury by emergency department physicians may be more effective at restoring the optimal tension on the capsulolabral complex. This is due to the potential of hematoma formation beneath the labrum, which may prevent anatomic reduction and therefore compromise the success of this treatment.

Every patient is different, and every shoulder within the same patient is also different. Variations in rehabilitation protocols (length of immobilization and the timing of initiation of motion exercises); in the definition of the actual injury (dislocation vs subluxation, acute vs chronic); in the categorization of the study patient (where the patient fits in the progressive spectrum instability: multidirectional instability with a traumatic event vs a pure primary traumatic anterior dislocation); in the quantification of the severity of the injury (simple Bankart lesion or large extension along the face of the glenoid both anteriorly and posteriorly); and in the presence of associated injuries (SLAP tear, glenoid bony defects, Hill-Sachs lesions, and rotator cuff tears); as well as the lack of group stratification in studies with respect to age (young patients tend to be more active), sex (men tend to be involved in more contact sports), and level of activity (football players and military recruits) create variability in diagnosis and treatment that may ultimately affect outcomes.

There is an urgent need in the orthopedic literature for a level-1 evidence, multicenter, randomized clinical trial, with clearly defined inclusion and exclusion criteria, a specific rehabilitation protocol, and precise outcome measures that will ultimately settle this debate.

Dr Nguyen is from the Division of Orthopedic Surgery, William Osler Health System, Toronto, Ontario, Canada.


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