Clinical Review

Traumatic Anterior Shoulder Instability: The US Military Experience

Am J Orthop. 2017 July;46(4):184-189

References

2. Owens BD, Duffey ML, Nelson BJ, DeBerardino TM, Taylor DC, Mountcastle SB. The incidence and characteristics of shoulder instability at the United States Military Academy. Am J Sports Med. 2007;35(7):1168-1173.

3. Owens BD, Nelson BJ, Duffey ML, et al. Pathoanatomy of first-time, traumatic, anterior glenohumeral subluxation events. J Bone Joint Surg Am. 2010;92(7):1605-1611.

4. DeBerardino TM, Arciero RA, Taylor DC, Uhorchak JM. Prospective evaluation of arthroscopic stabilization of acute, initial anterior shoulder dislocations in young athletes. Two- to five-year follow-up. Am J Sports Med. 2001;29(5):586-592.

5. Aronen JG, Regan K. Decreasing the incidence of recurrence of first time anterior shoulder dislocations with rehabilitation. Am J Sports Med. 1984;12(4):283-291.

6. Wheeler JH, Ryan JB, Arciero RA, Molinari RN. Arthroscopic versus nonoperative treatment of acute shoulder dislocations in young athletes. Arthroscopy. 1989;5(3):213-217.

7. Bottoni CR, Wilckens JH, DeBerardino TM, et al. A prospective, randomized evaluation of arthroscopic stabilization versus nonoperative treatment in patients with acute, traumatic, first-time shoulder dislocations. Am J Sports Med. 2002;30(4):576-580.

8. Dickens JF, Owens BD, Cameron KL, et al. Return to play and recurrent instability after in-season anterior shoulder instability: a prospective multicenter study. Am J Sports Med. 2014;42(12):2842-2850.

9. Owens BD, DeBerardino TM, Nelson BJ, et al. Long-term follow-up of acute arthroscopic Bankart repair for initial anterior shoulder dislocations in young athletes. Am J Sports Med. 2009;37(4):669-673.

10. DeBerardino TM, Arciero RA, Taylor DC. Arthroscopic stabilization of acute initial anterior shoulder dislocation: the West Point experience. J South Orthop Assoc. 1996;5(4):263-271.

11. Bottoni CR, Smith EL, Berkowitz MJ, Towle RB, Moore JH. Arthroscopic versus open shoulder stabilization for recurrent anterior instability: a prospective randomized clinical trial. Am J Sports Med. 2006;34(11):1730-1737.

12. Owens BD, Cameron KL, Peck KY, et al. Arthroscopic versus open stabilization for anterior shoulder subluxations. Orthop J Sports Med. 2015;3(1):2325967115571084.

13. Burkhart SS, De Beer JF. Traumatic glenohumeral bone defects and their relationship to failure of arthroscopic Bankart repairs: significance of the inverted-pear glenoid and the humeral engaging Hill-Sachs lesion. Arthroscopy. 2000;16(7):677-694.14. Shaha JS, Cook JB, Rowles DJ, Bottoni CR, Shaha SH, Tokish JM. Clinical validation of the glenoid track concept in anterior glenohumeral instability. J Bone Joint Surg Am. 2016;98(22):1918-1923.

15. Mologne TS, Provencher MT, Menzel KA, Vachon TA, Dewing CB. Arthroscopic stabilization in patients with an inverted pear glenoid: results in patients with bone loss of the anterior glenoid. Am J Sports Med. 2007;35(8):1276-1283.

16. Markenstein JE, Jaspars KC, van der Hulst VP, Willems WJ. The quantification of glenoid bone loss in anterior shoulder instability; MR-arthro compared to 3D-CT. Skeletal Radiol. 2014;43(4):475-483.

17. Itoi E, Lee SB, Berglund LJ, Berge LL, An KN. The effect of a glenoid defect on anteroinferior stability of the shoulder after Bankart repair: a cadaveric study. J Bone Joint Surg Am. 2000;82(1):35-46.

18. Shaha JS, Cook JB, Song DJ, et al. Redefining “critical” bone loss in shoulder instability: functional outcomes worsen with “subcritical” bone loss. Am J Sports Med. 2015;43(7):1719-1725.

19. Piasecki DP, Verma NN, Romeo AA, Levine WN, Bach BR Jr, Provencher MT. Glenoid bone deficiency in recurrent anterior shoulder instability: diagnosis and management. J Am Acad Orthop Surg. 2009;17(8):482-493.

20. Provencher MT, Frank RM, Leclere LE, et al. The Hill-Sachs lesion: diagnosis, classification, and management. J Am Acad Orthop Surg. 2012;20(4):242-252.

21. Yamamoto N, Itoi E, Abe H, et al. Contact between the glenoid and the humeral head in abduction, external rotation, and horizontal extension: a new concept of glenoid track. J Shoulder Elbow Surg. 2007;16(5):649-656.

22. Di Giacomo G, Itoi E, Burkhart SS. Evolving concept of bipolar bone loss and the Hill-Sachs lesion: from “engaging/non-engaging” lesion to “on-track/off-track” lesion. Arthroscopy. 2014;30(1):90-98.

23. Metzger PD, Barlow B, Leonardelli D, Peace W, Solomon DJ, Provencher MT. Clinical application of the “glenoid track” concept for defining humeral head engagement in anterior shoulder instability: a preliminary report. Orthop J Sports Med. 2013;1(2):2325967113496213.

24. Arciero RA, Parrino A, Bernhardson AS, et al. The effect of a combined glenoid and Hill-Sachs defect on glenohumeral stability: a biomechanical cadaveric study using 3-dimensional modeling of 142 patients. Am J Sports Med. 2015;43(6):1422-1429.

25. Waterman BR, Chandler PJ, Teague E, Provencher MT, Tokish JM, Pallis MP. Short-term outcomes of glenoid bone block augmentation for complex anterior shoulder instability in a high-risk population. Arthroscopy. 2016;32(9):1784-1790.

26. Schroder DT, Provencher MT, Mologne TS, Muldoon MP, Cox JS. The modified Bristow procedure for anterior shoulder instability: 26-year outcomes in Naval Academy midshipmen. Am J Sports Med. 2006;34(5):778-786.

27. Provencher MT, Frank RM, Golijanin P, et al. Distal tibia allograft glenoid reconstruction in recurrent anterior shoulder instability: clinical and radiographic outcomes. Arthroscopy. 2017;33(5):891-897.

28. Tokish JM, Fitzpatrick K, Cook JB, Mallon WJ. Arthroscopic distal clavicular autograft for treating shoulder instability with glenoid bone loss. Arthrosc Tech. 2014;3(4):e475-e481.

Classifying Bone Loss and Recognizing Its Effects

Burkhart and De Beer¹³ helped define the role and significance of bone loss in the setting of shoulder instability. They defined significant bone loss as an engaging Hill-Sachs lesion of the humerus in an abducted and externally rotated position or an “inverted pear” lesion of the glenoid. Overall analysis revealed recurrence in 4% of cases without significant bone loss and 65% of cases with significant bone loss. In a subanalysis of contact-sport athletes in the setting of bone loss, the failure rate increased to 89%, from 6.5%. Aiding in the quantitative assessment of glenoid bone loss, Itoi and colleagues¹⁷ showed that 21% glenoid bone loss resulted in instability that would not be corrected by a soft-tissue procedure alone. Bone loss of 20% to 25% has since been considered a “critical amount,” above which an arthroscopic Bankart has been questioned. More recently, several authors have shown that even less bone loss can have a significant effect on outcomes. Shaha and colleagues¹⁸ established that a subcritical level of bone loss (13.5%) on the anteroinferior glenoid resulted in clinical failure (as determined with the Western Ontario Shoulder Instability Index) even in cases in which frank recurrence or subluxation was avoided. It is thought that, in recurrent instability, glenoid bone loss incident rate is as high as 90%, and the corresponding percentage of patients with Hill-Sachs lesions is almost 100%.^19,20 Thus, it is increasingly understood that bone loss is a bipolar issue and that both sides must be considered in order to properly address shoulder instability in this setting. In 2007, Yamamoto and colleagues²¹ introduced the glenoid track, a method for predicting whether a Hill-Sachs lesion will engage. Di Giacomo and colleagues²² refined the track concept to quantitatively determine which lesions will engage in the setting of both glenoid and humeral bone loss. Metzger and colleagues,²³ confirming the track concept arthroscopically, found that manipulation with anesthesia and arthroscopic visualization was well predicted by preoperative track measurements, and thus these measurements can be a good guide for surgical management (Figures 1A, 1B).

At Tripler Army Medical Center, Shaha and colleagues¹⁴ clinically validated the concept in a series of arthroscopic stabilization cases. They found that the recurrence rate was 8% for “on-track” patients’ and 75% for “off-track” patients treated with the same intervention. In addition, positive predictive value was 75% for the off-track measurement and 44% for the glenoid bone loss assessment alone. The authors recommended the preoperative off-track measurement over the glenoid bone loss assessment.

In an analysis of computer modeling of 3-D CT of patients who underwent Bankart repair, Arciero and colleagues²⁴ found that bipolar bone defects (glenoid bone loss combined with humeral head Hill-Sachs lesion) had an additive and combined negative effect on soft-tissue Bankart repair. In particular, soft-tissue Bankart repair could be compromised by a 2-mm glenoid defect combined with a medium-size Hill-Sachs lesion or, conversely, by a 4-mm glenoid defect combined with a small Hill-Sachs lesion (Figures 2A, 2B).

Strategies for Addressing Bone Loss in Anterior Shoulder Instability

Several approaches for managing bone loss in shoulder instability have been described—the most common being coracoid transfer (Latarjet procedure). Waterman and colleagues²⁵ recently studied the effects of coracoid transfer, distal tibial allograft, and iliac crest augmentation on anterior shoulder instability in US military patients treated between 2006 and 2012. Of 64 patients who underwent a bone block procedure, 16 (25%) had a complication during short-term follow-up. Complications included neurologic injury, pain, infection, hardware failure, and recurrent instability.

After undergoing 1 of the 3 procedures, 33% of patients had persistent pain, and 23% had recurrent instability. In an older, long-term study of Naval Academy midshipmen, patients who underwent a modified Bristow procedure between 1975 and 1979 demonstrated 70% good to excellent results at an average follow-up of 26.4 years.²⁶

The recurrent instability rate was 15%, with 9% of the cohort dislocating again and 6% of the cohort experiencing recurrent subluxation. Direct bone grafting to the glenoid has also been described. Provencher and colleagues²⁷ introduced use of distal tibial allograft in addressing bony deficiency, and clinical results were promising (Figures 3A-3C). Tokish and colleagues²⁸ introduced use of distal clavicular autograft in addressing these deficiencies but did not report clinical outcomes (Figures 4A-4C).

Conclusion

Traumatic anterior shoulder instability is a common pathology that continues to significantly challenge the readiness of the US military. Military surgeon-researchers have a long history of investigating approaches to the treatment of this pathology—applying good science to a large controlled population, using a single medical record, and demonstrating a commitment to return service members to the ready defense of the nation.

References

1. Owens BD, Dawson L, Burks R, Cameron KL. Incidence of shoulder dislocation in the United States military: demographic considerations from a high-risk population. J Bone Joint Surg Am. 2009;91(4):791-796.

2. Owens BD, Duffey ML, Nelson BJ, DeBerardino TM, Taylor DC, Mountcastle SB. The incidence and characteristics of shoulder instability at the United States Military Academy. Am J Sports Med. 2007;35(7):1168-1173.

3. Owens BD, Nelson BJ, Duffey ML, et al. Pathoanatomy of first-time, traumatic, anterior glenohumeral subluxation events. J Bone Joint Surg Am. 2010;92(7):1605-1611.

4. DeBerardino TM, Arciero RA, Taylor DC, Uhorchak JM. Prospective evaluation of arthroscopic stabilization of acute, initial anterior shoulder dislocations in young athletes. Two- to five-year follow-up. Am J Sports Med. 2001;29(5):586-592.

5. Aronen JG, Regan K. Decreasing the incidence of recurrence of first time anterior shoulder dislocations with rehabilitation. Am J Sports Med. 1984;12(4):283-291.

6. Wheeler JH, Ryan JB, Arciero RA, Molinari RN. Arthroscopic versus nonoperative treatment of acute shoulder dislocations in young athletes. Arthroscopy. 1989;5(3):213-217.

7. Bottoni CR, Wilckens JH, DeBerardino TM, et al. A prospective, randomized evaluation of arthroscopic stabilization versus nonoperative treatment in patients with acute, traumatic, first-time shoulder dislocations. Am J Sports Med. 2002;30(4):576-580.

8. Dickens JF, Owens BD, Cameron KL, et al. Return to play and recurrent instability after in-season anterior shoulder instability: a prospective multicenter study. Am J Sports Med. 2014;42(12):2842-2850.

9. Owens BD, DeBerardino TM, Nelson BJ, et al. Long-term follow-up of acute arthroscopic Bankart repair for initial anterior shoulder dislocations in young athletes. Am J Sports Med. 2009;37(4):669-673.

10. DeBerardino TM, Arciero RA, Taylor DC. Arthroscopic stabilization of acute initial anterior shoulder dislocation: the West Point experience. J South Orthop Assoc. 1996;5(4):263-271.

11. Bottoni CR, Smith EL, Berkowitz MJ, Towle RB, Moore JH. Arthroscopic versus open shoulder stabilization for recurrent anterior instability: a prospective randomized clinical trial. Am J Sports Med. 2006;34(11):1730-1737.

12. Owens BD, Cameron KL, Peck KY, et al. Arthroscopic versus open stabilization for anterior shoulder subluxations. Orthop J Sports Med. 2015;3(1):2325967115571084.

13. Burkhart SS, De Beer JF. Traumatic glenohumeral bone defects and their relationship to failure of arthroscopic Bankart repairs: significance of the inverted-pear glenoid and the humeral engaging Hill-Sachs lesion. Arthroscopy. 2000;16(7):677-694.14. Shaha JS, Cook JB, Rowles DJ, Bottoni CR, Shaha SH, Tokish JM. Clinical validation of the glenoid track concept in anterior glenohumeral instability. J Bone Joint Surg Am. 2016;98(22):1918-1923.

15. Mologne TS, Provencher MT, Menzel KA, Vachon TA, Dewing CB. Arthroscopic stabilization in patients with an inverted pear glenoid: results in patients with bone loss of the anterior glenoid. Am J Sports Med. 2007;35(8):1276-1283.

16. Markenstein JE, Jaspars KC, van der Hulst VP, Willems WJ. The quantification of glenoid bone loss in anterior shoulder instability; MR-arthro compared to 3D-CT. Skeletal Radiol. 2014;43(4):475-483.

17. Itoi E, Lee SB, Berglund LJ, Berge LL, An KN. The effect of a glenoid defect on anteroinferior stability of the shoulder after Bankart repair: a cadaveric study. J Bone Joint Surg Am. 2000;82(1):35-46.

18. Shaha JS, Cook JB, Song DJ, et al. Redefining “critical” bone loss in shoulder instability: functional outcomes worsen with “subcritical” bone loss. Am J Sports Med. 2015;43(7):1719-1725.

19. Piasecki DP, Verma NN, Romeo AA, Levine WN, Bach BR Jr, Provencher MT. Glenoid bone deficiency in recurrent anterior shoulder instability: diagnosis and management. J Am Acad Orthop Surg. 2009;17(8):482-493.

20. Provencher MT, Frank RM, Leclere LE, et al. The Hill-Sachs lesion: diagnosis, classification, and management. J Am Acad Orthop Surg. 2012;20(4):242-252.

21. Yamamoto N, Itoi E, Abe H, et al. Contact between the glenoid and the humeral head in abduction, external rotation, and horizontal extension: a new concept of glenoid track. J Shoulder Elbow Surg. 2007;16(5):649-656.

22. Di Giacomo G, Itoi E, Burkhart SS. Evolving concept of bipolar bone loss and the Hill-Sachs lesion: from “engaging/non-engaging” lesion to “on-track/off-track” lesion. Arthroscopy. 2014;30(1):90-98.

23. Metzger PD, Barlow B, Leonardelli D, Peace W, Solomon DJ, Provencher MT. Clinical application of the “glenoid track” concept for defining humeral head engagement in anterior shoulder instability: a preliminary report. Orthop J Sports Med. 2013;1(2):2325967113496213.

24. Arciero RA, Parrino A, Bernhardson AS, et al. The effect of a combined glenoid and Hill-Sachs defect on glenohumeral stability: a biomechanical cadaveric study using 3-dimensional modeling of 142 patients. Am J Sports Med. 2015;43(6):1422-1429.

25. Waterman BR, Chandler PJ, Teague E, Provencher MT, Tokish JM, Pallis MP. Short-term outcomes of glenoid bone block augmentation for complex anterior shoulder instability in a high-risk population. Arthroscopy. 2016;32(9):1784-1790.

26. Schroder DT, Provencher MT, Mologne TS, Muldoon MP, Cox JS. The modified Bristow procedure for anterior shoulder instability: 26-year outcomes in Naval Academy midshipmen. Am J Sports Med. 2006;34(5):778-786.

27. Provencher MT, Frank RM, Golijanin P, et al. Distal tibia allograft glenoid reconstruction in recurrent anterior shoulder instability: clinical and radiographic outcomes. Arthroscopy. 2017;33(5):891-897.

28. Tokish JM, Fitzpatrick K, Cook JB, Mallon WJ. Arthroscopic distal clavicular autograft for treating shoulder instability with glenoid bone loss. Arthrosc Tech. 2014;3(4):e475-e481.

Traumatic Anterior Shoulder Instability: The US Military Experience

References

Classifying Bone Loss and Recognizing Its Effects

Strategies for Addressing Bone Loss in Anterior Shoulder Instability

Conclusion

Pages

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