Original Research

The Effect of Arthroscopic Rotator Interval Closure on Glenohumeral Volume

Am J Orthop. 2015 June;44(6):E190-E194

References

1. Creighton RA, Romeo AA, Brown FM, Hayden JK, Verma NN. Revision arthroscopic shoulder instability repair. Arthroscopy. 2007;23(7):703-709.

2. Gartsman GM, Roddey TS, Hammerman SM. Arthroscopic treatment of anterior-inferior glenohumeral instability. Two to five-year follow-up. J Bone Joint Surg Am. 2000;82(7):991-1003.

3. Gartsman GM, Taverna E, Hammerman SM. Arthroscopic rotator interval repair in glenohumeral instability: description of an operative technique. Arthroscopy. 1999;15(3):330-332.

4. Neer CS 2nd, Foster CR. Inferior capsular shift for involuntary inferior and multidirectional instability of the shoulder: a preliminary report. J Bone Joint Surg Am. 1980;62(6):897-908.

5. Neer CS 2nd. Displaced proximal humerus fractures: I. Classification and evaluation. J Bone Joint Surg Am. 1970;52(6):1077-1089.

6. Nobuhara K, Ikeda H. Rotator interval lesion. Clin Orthop. 1987;(223):44-50.

7. Rowe CR, Zarins B, Ciullo JV. Recurrent anterior dislocation of the shoulder after surgical repair. J Bone Joint Surg Am. 1984;66(2):159-168.

8. Rowe CR, Zarins B. Recurrent transient subluxation of the shoulder. J Bone Joint Surg Am. 1981;63(6):863-872.

9. Stokes DA, Savoie FH, Field LD. Arthroscopic repair of anterior glenohumeral instability and rotator interval lesions. Orthop Clin North Am. 2003;34(4):529-539.

10. Taverna E, Sansone V, Battistella F. Arthroscopic rotator interval repair: the three-step all-inside technique. Arthroscopy. 2004;20 Suppl 2:105-109.

11. Treacy SH, Field LD, Savoie FH. Rotator interval capsule closure: an arthroscopic technique. Arthroscopy. 1997;13(1):103-106.

12. Field LD, Warren RF, O’Brien SJ, Altcheck DW, Wickiewicz TL. Isolated closure of rotator interval defects for shoulder instability. Am J Sports Med. 1995;23(5):557-563.

13. Harryman DT 2nd, Sidles JA, Harris SL, Matsen FA 3rd. The role of the rotator interval capsule in passive motion and stability of the shoulder. J Bone Joint Surg Am. 1992;74(1):53-66.

14. Jost B, Koch PP, Gerber C. Anatomy and functional aspects of the rotator interval. J Shoulder Elbow Surg. 2000;9(4):336-341.

15. Plausinis D, Bravman JT, Heywood C, Kummer FJ, Kwon YM, Jazrawi LM. Arthroscopic rotator interval closure: effect of sutures on glenohumeral motion and anterior-posterior translation. Am J Sports Med. 2006;34(10):1656-1661.

16. Provencher MT, Mologne TS, Hongo M, Zhao K, Tasto JP, An KN. Arthroscopic versus open rotator interval closure: biomechanical evaluation of stability and motion. Arthroscopy. 2007;23(6):583-592.

17. Selecky MT, Tibone JE, Yang BY, et al. Glenohumeral joint translation after thermal capsuloplasty of the rotator interval. J Shoulder Elbow Surg. 2003;12(2):139-143.

18. Wolf R, Zheng N, Iero J, Weichel D. The effects of thermal capsulorrhaphy and rotator interval closure on multidirectional laxity in the glenohumeral joint: a cadaveric biomechanical study. Arthroscopy. 2004;20(10):1044-1049.

19. Yamamoto N, Itoi E, Tuoheti Y, et al. Effect of rotator interval closure on glenohumeral stability and motion: a cadaveric study. J Shoulder Elbow Surg. 2006;15(6):750-758.

20. Yamamoto N, Itoi E, Tuoheti Y, et al. The effect of the inferior capsular shift on shoulder intra-articular pressure: a cadaveric study. Am J Sports Med. 2006;34(6):939-944.

21. Cole BJ, Rodeo SA, O’Brien SJ, et al. The anatomy and histology of the rotator interval capsule of the shoulder. Clin Orthop. 2001;(390):129-137.

22. Lee HJ, Kim NR, Moon SG, Ko SM, Park JY. Multidirectional instability of the shoulder: rotator interval dimension and capsular laxity evaluation using MR arthrography. Skeletal Radiol. 2013;42(2):231-238.

23. Warner JP, Deng X, Warren RF, Torzilli PA, O’Brien SJ. Superoinferior translation in intact and vented glenohumeral joint. J Shoulder Elbow Surg. 1993;2(2):99-105.

24. Chechik O, Maman E, Dolkart O, Khashan M, Shabtai L, Mozes G. Arthroscopic rotator interval closure in shoulder instability repair: a retrospective study. J Shoulder Elbow Surg. 2010;19(7):1056-1062.

25. Chiang, E, Wang J, Wang S, et al. Arthroscopic posteroinferior capsular plication and rotator interval closure after Bankart repair in patients with traumatic anterior glenohumeral instability—a minimum follow-up of 5 years. Injury. 2010;41(10):1075-1078.

26. Karas SG, Creighton RA, DeMorat GJ. Glenohumeral volume reduction in arthroscopic shoulder reconstruction: a cadaveric analysis of suture plication and thermal capsulorrhaphy. Arthroscopy. 2004;20(2):179-184.

27. Miller MD, Larsen KM, Luke T, Leis HT, Plancher KD. Anterior capsular shift volume reduction: an in vitro comparison of 3 techniques. J Shoulder Elbow Surg. 2003;12(4):350-354.

28. Luke TA, Rovner AD, Karas SG, Hawkins RJ, Plancher KD. Volumetric change in the shoulder capsule after open inferior capsular shift versus arthroscopic thermal capsular shrinkage: a cadaveric model. J Shoulder Elbow Surg. 2004;13(2):146-149.

29. Ponce BA, Rosenzweig SD, Thompson KJ, Tokish J. Sequential volume reduction with capsular plications: relationship between cumulative size of plications and volumetric reduction for multidirectional instability of the shoulder. Am J Sports Med. 2011;39(3):526-531.

30. Lubowitz J, Bartolozzi A, Rubenstein D, et al. How much does inferior capsular shift reduce shoulder volume? Clin Orthop. 1996;(328):86-90.

31. Moon YL, Singh H, Yang H, Chul LK. Arthroscopic rotator interval closure by purse string suture for symptomatic inferior shoulder instability. Orthopedics. 2011;34(4).

32. Jerosch J, Castro WH. Shoulder instability in Ehlers-Danlos syndrome: an indication for surgical treatment? Acta Orthop Belg. 1990;56(2):451-453.

33. Schenk TJ, Brems JJ. Multidirectional instability of the shoulder: pathophysiology, diagnosis, and management. J Am Acad Orthop Surg. 1998;6(1):65-72.

34. Cohen SB, Wiley W, Goradia VK, Pearson S, Miller MD. Anterior capsulorrhaphy: an in vitro comparison of volume reduction. Arthroscopic plication versus open capsular shift. Arthroscopy. 2005;21(6):659-664.

Initial studies proposed that rotator interval closure limited inferior and posterior translation.³⁰ More recent studies have demonstrated that rotator interval closure confers little effect on posterior instability but increases anterior stability in cadaveric models.^15,16 Clinical series have provided evidence that rotator interval closure can increase anterior stability.^1,3,7,9,12 In a series of isolated rotator interval closures for multidirectional instability, Field and colleagues¹² found that preoperative anterior and inferior symptoms predominated over posterior symptoms. Isolated closure of the rotator interval resulted in 100% excellent results with no cases of recurrent instability. Moon and colleagues³¹ reported that arthroscopic rotator interval closure with or without inferior capsular plication in multidirectional instability and predominant symptomatic inferior instability has shown benefit by improving function and stability. Other clinical reports of rotator interval closure in conjunction with arthroscopic Bankart repair have suggested it has an additive effect on anterior shoulder stability without limiting motion.^24,25

In our study, arthroscopic closure of the rotator interval with 2 superior-to-inferior stitches reduced intracapsular volume by 45%. Even though open capsular shifts use different surgical techniques, similar technique volume reduction studies have reported reductions between 34% and 54% with open shifts.^27,30 It is unknown if the stability resulting from decreased GHV is primarily from increasing intra-articular pressures or from restricting ROM, or from a combination of both. In shoulders with multidirectional instability, the joint volume may be increased, the joint capsule may be enlarged, or the glenohumeral ligaments may be lax and thin.^4,6,32,33 Yamamoto and colleagues¹⁹ stated that intra-articular pressure is determined by 3 factors: load, joint volume, and material properties of the capsule. Load is a constant; joint volume and material properties can be changed.¹⁹ In our study, material properties were controlled by using a majority of matched specimens. Regardless of the stabilizing mechanism, our study results demonstrated that arthroscopic rotator interval closure may be a powerful tool in reducing shoulder volume, a consistent principle of surgical techniques used in reestablishing shoulder stability.^19,20

When a single rotator interval closure stitch was used, volume reduction with a lateral stitch was superior to that with a medial stitch. This finding is logical, as anatomically the dimensions of the rotator interval are larger laterally as the CHL fans out to insert on the greater and lesser tuberosities.¹⁴ This finding has also been reported in open capsular shifts for multidirectional instability, with a lateral humeral shift having a larger volume reduction than a medial glenoid shift.²⁷ Miller and colleagues²⁷ used the image of a cone, with its larger opening facing the humerus and narrower side facing the glenoid, to illustrate this difference in open capsular shifts.

Our study also showed a larger volume reduction with 2 rotator interval closure stitches than with a single interval stitch. As ROM testing has not shown a difference between results with 1 and 2 sutures, we recommend a minimum of 2 sutures for arthroscopic rotator interval closure.¹⁵ If a single plication stitch is preferred, a lateral stitch (vs a medial stitch) can be used for a significantly larger reduction in shoulder volume. We think this is because of a larger amount of capsule being purchased with lateral closure (Figure 5). However, if a medial stitch is used, it is important to not place it too near the glenoid to avoid CHL tethering and subsequent excessive loss of external rotation.¹⁵

This study had several weaknesses. First, it was a cadaveric study, and use of specimens not known to have instability or specific rotator interval injury may make generalization to a clinical situation difficult. Second, although our power analysis called for 5 shoulders in each group, full-thickness rotator cuff tears rendered 2 shoulders unusable. This reduced our sample sizes and potentially decreased the power of the study, though the data demonstrated statistically significant differences. Third, we did not compare the effects of an open medial-to-lateral imbrication of the rotator interval on intracapsular volume with the effects of our arthroscopic method. We also did not assess our specimens’ ROM, effects of interval closure stitches on shoulder stability, or glenohumeral contact surface pressures, as these factors have already been studied.^13-19 Instead, we focused on the effects of rotator interval closure on intracapsular volume, which had not been quantified until now. The clinical significance of such a volume reduction is unknown, especially with respect to influence on ROM, but the degree of volume reduction was larger than with previously reported arthroscopic instability repairs and smaller than with open capsular shifts, demonstrating that it may be a powerful tool in restoring stability in an unstable shoulder.^26-30,34 Fourth, the role of isolated rotator interval closure is poorly defined, as only 1 clinical series of isolated rotator interval closure has been reported thus far.¹² It has been far more common for rotator interval closure to be used with Bankart repair or capsulorrhaphy.^1-3,7-9