Copyright © 2007 by The Journal of Bone and Joint Surgery, Inc.

Commentary & Perspective

Commentary & Perspective on
"Can the Need for Future Surgery for Acute Traumatic Anterior Shoulder Dislocation Be Predicted?"
by Raymond A. Sachs, MD, et al.

Commentary & Perspective by
Bertram Zarins, MD*,
Massachusetts General Hospital, Boston, Massachusetts

Posted August 2007

This study confirms that the younger a patient is at the time of initial traumatic anterior shoulder dislocation, the more likely it will be that the patient will sustain a recurrent dislocation (Table I). This finding was previously reported by Rowe and Sakellarides1, Hovelius et al.2, te Slaa et al.3, and others4-6. The information is very useful when discussing the likelihood of recurrent shoulder instability with a patient who has just dislocated the shoulder for the first time.
TABLE I Age of Patient at the Time of Primary Dislocation in Relation to the Prevalence of Recurrence
Study Length of
Follow-up		 Age Range
(yr)		 No. of
Patients with
Primary
Dislocation		 No. of
Patients with
Recurrences
Rowe and Sakellarides (1961)
1 to 10 yr
11-20
 49
46 (94%)
 
21-30
 64
51 (80%)
 
31-40
 16
  8 (50%)
 
41-90
188
 27 (14%)
Total
317
132 (42%)
 
Hovelius et al. (1996)
10 yr
12-22
102
 68 (67%)
 
23-29
 60
 35 (58%)
 
30-40
 95
 25 (26%)
Total
257
128 (50%)
 
Kralinger et al. (2002)
1 to 6 yr
 0-20
 12
 2 (17%)
 
21-30
 31
19 (61%)
 
31-40
 26
 9 (35%)
 
>40
111
23 (21%)
Total
180
53 (29%)
 
te Slaa et al. (2004)
4 to 7 yr
<20
 14
 9 (64%)
 
20-40
 43
16 (37%)
 
>40
 50
 3 (06%)
Total
107
28 (26%)
 
Sachs et al. (2007)
2 to 5 yr
12-19
 39
22 (56%)
 
20-29
 29
11 (38%)
 
30-39
 22
 6 (27%)
 
≥40
 41
 4 (10%)
Total
131
43 (33%)

This study also confirms previous reports that rotator cuff tears are more common in patients who are older than forty years at the time of initial shoulder dislocation. At least eight of forty-one patients who were over the age of forty had torn rotator cuffs; in contrast, only one of ninety younger patients had a concomitant rotator cuff tear.

One patient in this series was found to have a torn rotator cuff interval. This pathological finding was first reported by Rowe and Zarins in 19817. An interval tear is not really a true rotator cuff tear, but an enlargement of a normal space. A separation between the anterior edge of the supraspinatus tendon and the superior edge of the subscapularis tendon normally exists and is necessary to allow full shoulder motion. The seam between the two tendons can tear when a shoulder dislocates anteriorly. As the shoulder dislocates, the subscapularis tendon follows the humeral head anteroinferiorly, but the supraspinatus is restrained by the intervening coracoid process. The rotator cuff itself does not tear.

I disagree with the concept, as presented in this report, that patients "require" or "need" surgery. Whether or not a patient has an operation depends on a number of factors, many of which are socioeconomic. A surgeon can greatly influence a patient's decision to undergo surgery, and patients vary widely in their reasons to undergo or abstain from surgery. A military cadet or a professional athlete will probably make a different choice in submitting to surgery than would a person whose livelihood is not affected by the disorder. One cannot equate the performance of surgery with the need for surgery.

*The author did not receive any outside funding or grants in support of his research for or preparation of this work. Neither he nor a member of his immediate family 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 author, or a member of his immediate family, is affiliated or associated.

References

1. Rowe CR, Sakellarides HT. Factors related to recurrences of anterior dislocations of the shoulder. Clin Orthop. 1961;20:40-8.
2. 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.
3. te Slaa RL, Wijffels MP, Brand R, Marti RK. The prognosis following acute primary glenohumeral dislocation. J Bone Joint Surg Br. 2004;86:58-64.
4. Krazar B, Relovszky E. Prognosis of primary dislocation of the shoulder. Acta Orthop Scand. 1969;40:216-24.
5. Simonet WT, Melton LJ, Cofield RH, Ilstrup DM. Incidence of anterior shoulder dislocation in Olmsted County, Minnesota. Clin Orthop Relat Res. 1984;186:186-91.
6. 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.
7. Rowe CR, Zarins B. Recurrent transient subluxation of the shoulder. J Bone Joint Surg Am. 1981;63:863-72.