Anterior instability at the shoulder can be due to a trauma, repetitive trauma, a tendency for a loose joint capsule/soft tissue, or multi-factorial.
For athletes who experience recurrent, painful episodes of dislocation, surgery may be required to stabilize the shoulder joint.
Individuals with anterior instability are generally uncomfortable or “apprehensive” in the abducted and externally rotated “high-five” position
Common exercises such as behind the neck military press, dumbbell press, pectoral flies using certain seated machines, back squats, and behind the neck pull-downs require assumption of the high-five position.
Balanced strength between the rotator cuff and scapular musculature plays a critical role in positioning the glenoid fossa at an appropriate angle to create an ideal meeting point for the humeral head. Modifying exercises/grips/hand positions may serve to prevent and/or minimize symptoms.
Background: While a large volume of literature has focused on risk factors for anterior shoulder instability, the rates of recurrence
are inconsistent and require additional population-based epidemiologic data.
Purpose/Hypothesis: The purpose was to report the effect of patient age on the number of instability events before physician
consultation, rate of surgical stabilization, recurrent instability, and progression to osteoarthritis in patients \40 years old with
anterior shoulder instability, utilizing an established US geographic population. We hypothesized that younger patients would
be more likely to experience multiple episodes of instability before evaluation, undergo surgery, and experience recurrent instability after surgical intervention.
Study Design: Descriptive epidemiologic study.
Methods: An established geographic database of more than 500,000 patients was used to identify patients\40 years of age with
anterior shoulder instability between 1994 and 2016. Medical records were reviewed to obtain patient characteristics, history,
imaging, surgical details, and outcomes. Patients were divided into 5 groups based on age (15, 16-20, 21-25, 26-30, and
31-40 years) at initial instability. Comparative analysis was performed to identify differences between groups.
Results: The study population consisted of 654 patients with a mean follow-up of 11.1 years (range, 2.0-25.2 years). This resulted
in 118 patients (18%) 15 years of age at initial instability; 250 (38%), 16 to 20 years; 110 (17%), 21 to 25 years; 80 (12%), 26 to 30
years; and 96 (15%), 31 to 40 years. Of patients 15 years old at initial instability 47% had 31 instability events, compared with
12% of patients aged 31 to 40 years (P \ .001). At 10 years of follow-up, patients 15 and 16 to 20 years old demonstrated the
highest recurrent instability rates of 38.8% and 47.1% after nonoperative management, respectively. Patients 16 to 20 years old
demonstrated the highest rates of both surgical intervention (40.4%) and recurrence after surgery (24.8%). Patients 31 to 40 years
of age were significantly more likely to develop clinically symptomatic osteoarthritis (15.6%) than all other age groups.
Conclusion: In a US epidemiologic population of patients \40 years old, the rate of recurrent anterior shoulder instability was
roughly one-third after initial physician consultation. Younger patients, particularly those 15 and 16 to 20 years of age, were
more likely to have experienced multiple instability events at the time of initial evaluation, require surgery, and experience recurrent instability compared with older patients. For every year of decrease in age at initial instability, the risk of recurrent instability or surgical intervention after physician consultation increased by 4.1% and 2.8%, respectively.