Subacromial impingement in patients with whiplash injury to the cervical spine

BACKGROUND Impingement syndrome and shoulder pain have been reported to occur in a proportion of patients following whiplash injuries to the neck. In this study we aim to examine these findings to establish the association between subacromial impingement and whiplash injuries to the cervical spine. METHODS AND RESULTS We examined 220 patients who had presented to the senior author for a medico-legal report following a whiplash injury to the neck. All patients were assessed for clinical evidence of subacromial impingement. 56/220 patients (26%) had developed shoulder pain following the injury; of these, 11/220 (5%) had clinical evidence of impingement syndrome. Only 3/11 patients (27%) had the diagnosis made prior to evaluation for their medico-legal report. In the majority, other clinicians had overlooked the diagnosis. The seatbelt shoulder was involved in 83% of cases (p < 0.03). CONCLUSION After a neck injury a significant proportion of patients present with shoulder pain, some of whom have treatable shoulder pathology such as impingement syndrome. The diagnosis is, however, frequently overlooked and shoulder pain is attributed to pain radiating from the neck resulting in long delays before treatment. It is important that this is appreciated and patients are specifically examined for signs of subacromial impingement after whiplash injuries to the neck. Direct seatbelt trauma to the shoulder is one possible explanation for its aetiology.