Anterior Shoulder Instability in the Military Athlete

Abstract

Context: Given its young, predominately male demographics and intense physical demands, the US military remains an ideal cohort for the study of anterior shoulder instability.

Evidence acquisition: A literature search of PubMed, MEDLINE, and the Cochrane Database was performed to identify all peer-reviewed publications from 1950 to 2016 from US military orthopaedic surgeons focusing on the management of anterior shoulder instability.

Study design: Clinical review.

Level of evidence: Level 4.

Results: The incidence of anterior shoulder instability events in the military occurs at an order of magnitude greater than in civilian populations, with rates as high as 3% per year among high-risk groups. With more than 90% risk of a Bankart lesion and high risk for instability recurrence, the military has advocated for early intervention of first-time shoulder instability while documenting up to 76% relative risk reduction versus nonoperative treatment. Preoperative evaluation with advanced radiographic imaging should be used to evaluate for attritional bone loss or "off-track" engaging defects to guide comprehensive surgical management. With complex recurrent shoulder instability and/or cases of clinically significant osseous lesions, potential options such as remplissage, anterior open capsular procedures, or bone augmentation procedures may be preferentially considered.

Conclusion: Careful risk stratification, clinical evaluation, and selective surgical management for at-risk military patients with anterior shoulder instability can optimize the recurrence risk and functional outcome in this population.

Keywords: anterior; dislocation; military; shoulder instability; subluxation.

Figure 1.

(a) Calculation of the glenoid track. The inferior two-thirds of the glenoid approximates a circle, and the diameter of this circle represents the expected diameter of the glenoid. The glenoid track is calculated as 0.83 × diameter (yellow circle). Bone loss (red line) is measured as the distance from the edge of the circle to the edge of the remaining bone (black line) and is subtracted from the glenoid track measure. (b) Calculation of the Hill-Sachs lesion (HSL). On sagittal view, demonstrating the maximum bone defect, the HSL is the distance from the insertion of the rotator cuff to the medial edge of the HSL. The yellow line represents the Hill-Sachs defect, and the red line represents the bone bridge between it and the insertion of the cuff. These lines are added together to characterize the Hill-Sachs lesion used in the calculation of the glenoid track.

Figure 2.

(a) Arthroscopic view of a right shoulder from the anterior superior portal. A Hill-Sachs lesion is visualized with suture anchor placed through the infraspinatus tendon and capsule and inserted into the posterior aspect of the defect. The drill guide is positioned for the second anterior anchor. (b) After completion of the remplissage, the tendon is approximated at the edge of the articular cartilage defect, effectively excluding the Hill-Sachs defect from the joint.

Figure 3.

A right shoulder at the completion of Latarjet bone block transfer. A Fukuda retractor retracts the humeral head and a glenoid retractor is placed medially. A pair of forceps is placed on the edge of the coracoacromial ligament, which will be used for capsular reconstruction. The 2 visualized screws are placed through the coracoid bone block parallel with the glenoid surface.

Figure 4.

Distal clavicle transfer to bone using suture anchors demonstrating the potential of an autograft distal clavicle to reconstruct anterior glenoid bone loss.