Superior humeral head migration might be a radiological aid in diagnosing patients with adhesive capsulitis of the shoulder

Abstract

Background: The diagnosis of adhesive capsulitis (AC) of the shoulder might be challenging, as it is a diagnosis of exclusion and mainly based on the clinical examination. The purpose of the present study was to investigate the validity and reliability of 4 commonly reported radiological parameters suggesting a superior humeral head migration on anteroposterior (a/p) shoulder radiograph in identifying patients with AC.

Methods: The a/p shoulder radiographs of 100 patients with AC and 100 control subjects were retrospectively reviewed. A disruption of the normal scapulohumeral arch (≥2 mm), the acromiohumeral interval (AHI), the inferior glenohumeral distance (IGHD), and the upward migration index (UMI) were measured.

Results: A disruption of the scapulohumeral arch was observed in 80% in the AC and 20% in the control group. The mean AHI was 9.3 ± 1.3 mm and 11.0 ± 1.7 mm (P < .001), the mean IGHD was 3.9 ± 3.0 mm and 0.9 ± 1.9 mm (P < .001), and the mean UMI was 1.37 ± 0.1 and 1.44 ± 0.1 (P < .001) in patients with AC and control subjects, respectively. The scapulohumeral arch's disruption demonstrated the best test characteristics with a sensitivity and specificity of 80% in detecting patients with an AC. Patients with a disruption of the scapulohumeral arch had 16 times increased odds of having an AC.

Conclusion: Measuring the superior humeral head migration might be a simple and clinically relevant tool in diagnosing an AC of the shoulder and could be reliably used by clinicians adjacent to the clinical examination without any additional cost. Especially a disruption of the scapulohumeral arch on the a/p shoulder radiograph should raise concerns of AC in the absence of a massive rotator cuff tear.

Keywords: Acromiohumeral interval; Adhesive capsulitis; Diagnosis; Frozen shoulder; Radiograph; Superior humeral head migration.

Figure 1

Anteroposterior shoulder radiograph in a patient with AC demonstrating the disruption of the glenohumeral arch (dashed blue line), the AHI (yellow double arrow), the IGHD (red double arrow) in a patient with AC. The UMI was defined as the distance between the lowest point of the acromion and the Center of the humeral head (orange arrow), divided by the radius of the humeral head (green arrow). AC, adhesive capsulitis; AHI, acromiohumeral interval; IGHD, inferior glenohumeral distance; UMI, upward migration index.