AANA/ASES JOINT WEBINAR: Shoulder instability: When to operate?-Feeley Article

Feeley Article

Pdf Summary

This retrospective study compared bipolar bone loss—specifically glenoid bone loss, Hill-Sachs lesion size, and glenoid track status—between adolescents (ages 10-19) and adults (≥20) with anterior shoulder dislocations. The cohort included 45 adolescents (mean age 16.1) and 30 adults (mean age 28.9) who underwent MRI evaluation. Bipolar bone loss was assessed by measuring glenoid bone loss (using the best-fit circle technique) and Hill-Sachs lesion size (distance between medial rotator cuff margin and medial Hill-Sachs lesion margin). Lesions were categorized as "on track" if the Hill-Sachs lesion remained within the glenoid track and "off track" if extending medially beyond the track, indicating higher engagement risk and recurrent instability.<br /><br />Key findings showed no significant difference in average glenoid bone loss (adolescents 8.4%, adults 9.9%; P=0.23) or Hill-Sachs lesion size (adolescents 12.7 mm, adults 9.9 mm; P=0.12) between groups. However, off-track lesions were significantly more common in adolescents (24.4%) than adults (3.3%), conferring a 9.4-fold increased risk (odds ratio 9.38). Subgroup analysis identified multiple dislocations as an independent risk factor for off-track lesions (odds ratio 4.15), with multiple dislocators displaying larger Hill-Sachs lesions but similar glenoid bone loss versus single dislocators.<br /><br />The study supports that adolescence and multiple dislocations are independent risk factors for higher likelihood of off-track shoulder lesions, possibly contributing to the higher recurrence rates seen in younger patients. Since adolescents are more likely to sustain these lesions during contact or high-risk sports, bipolar shoulder assessment incorporating glenoid track evaluation is particularly important in this population to guide treatment decisions.<br /><br />Limitations include retrospective design, predominance of male patients, reliance on MRI rather than CT, and measurement variability; however, intra- and interobserver reliability were adequate. The authors suggest further investigation into optimal management strategies for off-track bipolar bone loss in adolescent and recurrent shoulder dislocators.

Keywords

bipolar bone loss

glenoid bone loss

Hill-Sachs lesion

glenoid track

anterior shoulder dislocation

adolescents

adults

off-track lesions

multiple dislocations

MRI evaluation