Investigation of the interaction between shoulder and cervical vertebral pathologies in isolated shoulder pain: clinical and morphological aspects

BACKGROUND: The anatomical interaction and overlap between the cervical vertebra and the shoulder presents a diagnostic challenge for both orthopedic surgeons and neurosurgeons. Musculoskeletal disorders, affecting 1.71 billion people globally, often involve shoulder pain, which is frequently linked to cervical issues. Understanding this connection is crucial for accurate diagnosis and treatment. This study aimed to explore potential structural associations between annular bulging and shoulder pathologies in patients presenting with isolated shoulder pain. METHODS: Using a retrospective screening approach, we analyzed MRI images of patients admitted to the Orthopedics Clinic between 2017 and 2019 who presented with pain in the shoulder region, identified through the Hospital Management Information System. A total of 618 patients were included, and their demographic details, along with shoulder and cervical pathologies, were recorded and assessed. The association between annular bulging and shoulder pathologies was evaluated using regression models as sex and age covariants. RESULTS: In this study of 618 patients with isolated shoulder pain, 61.3% were female (n = 379), and the mean age of the patient group was 51.66 ± 9.5 years. Pathological findings appeared in 47.7% of cases in both cervical spine and shoulder MRIs, with 24.1% showing pathology only in shoulder MRIs and 5.7% only in cervical MRIs. Annular bulging was most common, especially in the C5-C6 segment. Women exhibited a higher incidence of acromion type 2 morphology and subcoracoid effusion, while men commonly had subcoracoid effusion and acromioclavicular joint arthrosis. CONCLUSIONS: This exploratory study demonstrates morphological associations between cervical spine and shoulder pathologies in patients presenting with shoulder pain. It is imperative to interpret these findings as descriptive structural correlations rather than causal relationships. The observed co-occurrence is likely to reflect shared degenerative and biomechanical processes affecting adjacent anatomical regions.