The relationship between chronic type III acromioclavicular joint dislocation and cervical spine symptoms

BACKGROUND: This study was aimed at evaluating if patients with chronic type III acromioclavicular dislocation develop more frequently cervical spine symptoms respect to normal subjects. METHODS: The cervical spine of 34 patients with chronic type III AC dislocation was radiographically evaluated. Osteophytosis presence was registered and the narrowing of the intervertebral disc and cervical lordosis were evaluated. Subjective cervical symptoms were investigated using the Northwick Park Neck Pain Questionnaire (NPQ). One-hundred healthy volunteers were recruited as a control group. RESULTS: The rate and distribution of osteophytosis and narrowed intervertebral disc were similar in both of the groups. Patients with chronic AC dislocation had a lower value of cervical lordosis. NPQ score was 17.3% in patients with AC separation (100% = the worst result) and 2.2% in the control group (p < 0.05). An inverse significant nonparametric correlation was found between the NPQ value and the lordosis degree in the AC dislocation group (p = 0.001) wheras results were not correlated (p = 0.27) in the control group.Fair values of NPQ also resulted in patients with AC dislocation and scapular dyskinesis CONCLUSIONS: Our study shows that chronic type III AC dislocation does not interfere with osteophytes formation or intervertebral disc narrowing, but that it may predispose cervical hypolordosis. The higher average NPQ values were observed in patients with chronic AC dislocation, especially in those that developed cervical hypolordosis. The higher mean NPQ values have been observed in patients with chronic AC dislocation, mainly in those who developed cervical hypolordosis and or scapular dyskinesis.