Glenohumeral internal rotation deficit after operative treatment of mid-shaft clavicle fractures: a subclinical, scapula-related phenomenon.

backgroundGlenohumeral internal rotation deficit (GIRD) is a well-recognized component of shoulder dysfunction and has been extensively described in overhead athletes within the framework of scapular dyskinesis. However, whether a similar or distinct pattern of GIRD exists after mid-shaft clavicle fractures remains insufficiently understood. This study aimed to evaluate the prevalence and features of GIRD in a post-traumatic population and to explore their potential relationship with scapular positioning.

methodsThis cross-sectional comparative study included 99 patients with healed mid-shaft clavicle fractures, comprising 62 patients treated with open reduction and internal fixation (ORIF) and 37 patients managed conservatively. Internal and external rotation were measured bilaterally using a standardized supine protocol, and side-to-side differences were calculated to identify GIRD. Scapular dyskinesis was assessed using the SICK Scapula Rating Scale, and subjective function was evaluated using the Disabilities of the Arm, Shoulder and Hand (DASH) score. Scapular orientation was indirectly and exploratorily assessed on standardized anteroposterior radiographs using group-specific projected area ratios. Within the ORIF cohort, exploratory analyses were also performed to identify factors potentially associated with postoperative GIRD.

resultsThe ORIF group demonstrated a significantly greater internal rotation deficit than the conservative group (25° [11.5, 27] vs. 0° [0, 5], P < 0.001). No significant difference in external rotation gain was observed between groups. The ORIF group also showed a significantly greater G-C ratio and higher SICK Scapula Rating Scale scores than the conservative group, while DASH scores remained similarly low in both groups. Within the ORIF cohort, 45 of 62 patients (72.6%) met the predefined criterion for GIRD. Compared with patients without GIRD, those with GIRD demonstrated significantly higher values for both the G-G ratio and the G-C ratio as well as higher SICK Scapula Rating Scale scores, but no significant difference in DASH scores. No routinely recorded demographic, injury-related, or peri-treatment variable was significantly associated with postoperative GIRD in the ORIF group.

conclusionGIRD appears to be a common but largely subclinical finding after operative treatment of mid-shaft clavicle fractures. In contrast to the pattern described in overhead athletes, this post-traumatic internal rotation deficit was not accompanied by external rotation gain, suggesting a potentially distinct underlying mechanism. The observed association with a tendency toward scapular protraction may provide insight into this phenomenon. Awareness of this pattern may be relevant to postoperative assessment and may help inform future studies aimed at optimizing rehabilitation strategies.