Use of Computed Tomography in the Evaluation of Anterior Shoulder Instability: Possible Effect on Surgical Management

Abstract

Background:

Glenoid bone loss is a critical factor in the management of anterior shoulder instability (ASI). Computed tomography (CT) is often considered the gold standard to evaluate glenoid bone loss, but it is associated with negative factors such as radiation. Thus, interest exists as to when orthopaedic surgeons need a CT scan to guide decision-making when treating ASI.

Purpose:

To determine whether information gained from a shoulder CT scan alters orthopaedic surgeons’ management plan for ASI and, secondarily, to determine whether surgeon- and patient-specific factors affect whether a CT scan changes treatment and which clinical factors are most important in surgical decision-making.

Study Design:

Cross-sectional study.

Methods:

A questionnaire composed of 24 ASI vignettes was administered to Herodicus Society members, American Shoulder and Elbow Surgeons Neer Circle members, and sports medicine fellowship–trained orthopaedic surgeons. Participants chose their recommended surgical treatment from the options of arthroscopic Bankart repair, open Bankart repair, bony reconstruction procedure, or other based on patient history, radiographs, and magnetic resonance imaging. Participants were then shown CT images and asked whether their treatment plan changed and, if not, whether the CT scan was not necessary or had reinforced their decision. Generalized linear mixed-effects logistic regression modeling was performed to assess the influence of vignette and respondent characteristics on treatment decisions.

Results:

A total of 74 orthopaedic surgeons completed the survey; 96% were fellowship trained (sports medicine, 50%; shoulder and elbow surgery, 41%), and 66% practiced in academic settings. CT imaging did not change the selected treatment strategy in 75.6% of responses. In cases when management did not change, surgeons reported that the CT scan reinforced their decision in 53.4% of responses and was not necessary for decision-making in 22.2% of responses. Decision-making was more likely to be changed after CT in male patients and those with off-track lesions.

Conclusion:

Information gained from a CT scan did not alter treatment decision-making in three-quarters of vignettes among surgeons experienced in the management of ASI. The finding that CT scans did alter the treatment plan in nearly a quarter of cases is not insignificant, and it appears that in patients with borderline glenoid track status and few other risk factors for recurrence after arthroscopic stabilization, CT imaging is more likely to change management.