Concomitant Rotator Cuff Tear with Frozen Shoulder: A Contemplation on the Necessity and Legitimacy of Magnetic Resonance Imaging Stratified by Age.

BACKGROUND

Frozen shoulder (FS) is often accompanied by a rotator cuff tear (RCT), but it can be challenging to diagnose a concomitant RCT without imaging studies. Therefore, having practical criteria to identify patients requiring imaging studies at initial presentation with FS would lead to more cost-effective use of these studies. This study investigated the relationship between RCT and stiffness in patients with FS and whether this relationship was modified by patient age.

METHODS

This study included 540 adults with shoulder pain who had ≥ 10° of limited passive range of motion in forward flexion, compared to the contralateral side. Patients were categorized into 2 groups depending on the degree of forward flexion stiffness: overhead stiffness (OHS) group, patients with ≥ 110° forward flexion (n = 349); and non-OHS group, patients with forward flexion < 110° (n = 191). The presence of concomitant RCT was determined by magnetic resonance imaging and compared between groups before and after stratification by age.

RESULTS

The OHS group had increased odds of concomitant RCT, compared to the non-OHS group (odds ratio [OR], 4.99; 95% CI, 3.36-7.42). OHS was also significantly associated with a more severe grade of RCT (no tear, partial-thickness tear, or full-thickness tear) (OR, 4.42; 95% CI, 3.05-6.39). The odds of RCT in the OHS group, compared to the non-OHS group, increased with age (50-59 years: OR, 3.83; 95% CI, 1.96-7.48; 60-69 years: OR, 5.94; 95% CI, 3.14-11.26; and 70-79 years: OR, 7.67; 95% CI, 2.71-21.66).

CONCLUSIONS

Patients with FS and forward flexion range of motion ≥ 110° (i.e., OHS) at initial presentation had approximately 5-fold higher odds of concurrent RCT than patients with non-OHS. Moreover, in patients aged 50 years or above, these odds increased up to almost 8-fold. Therefore, we recommend confirming the rotator cuff integrity with magnetic resonance imaging in patients with FS and OHS.