Study design: Retrospective cohort study.
Objective: To investigate the relationship between cervical spine (C-spine) and rotator cuff (RTC) pathology.
Summary of background data: Cervical spine and RTC pathology cause significant shoulder pain in isolation and in tandem, but there is limited information about the relationship between these 2 entities.
Methods: Patients with a diagnosis of C-spine and/or RTC pathology between 2005 and 2011 were identified using a large national database composed of private payer as well as Medicare patient records. Patients with concomitant C-spine and RTC diagnoses were then stratified by age group and sex. Patients with lumbar spine (L-spine) and RTC pathology were used as a comparative group, and multivariate logistic regression was used for statistical analysis.
Results: Concomitant C-spine and RTC diagnoses were identified in 86,928 patients representing 13% of 679,112 patients with a RTC diagnosis and 16% of 531,177 patients with a C-spine diagnosis. The association between C-spine and RTC pathology increased significantly with age as RTC diagnoses were present in 13% of patients with C-spine pathology younger than 60 years old but increased to 25% in C-spine patients older than 60 years (P<0.0001). For patients over 60 years old who developed a new C-spine diagnosis, 11% would develop a new RTC diagnosis or undergo an operation for a RTC disorder within 5 years. Lumbar diagnosis codes (2,297,480 patients) were over 4 times more common than C-spine codes but RTC pathology had a significantly higher correlation with C-spine pathology than L-spine pathology (odds ratio, 2.32) and patients with C-spine pathology were more likely to develop new rotator cuff pathology (odds ratio, 1.53).
Conclusions: The association between cervical spine and RTC pathology is significantly greater than that between L-spine and RTC pathology and increases substantially with patient age. Further studies are needed to elucidate the cause of this relationship.