Atraumatic shoulder instability: patient characteristics, comorbidities, and disability

BACKGROUND: Atraumatic shoulder instability of the shoulder is well described, and numerous extrinsic factors have been identified as having a negative influence on long-term shoulder function, including age, sex, smoking, and workers' compensation status. Furthermore, physical factors such as acute or chronic pain, as well as psychological comorbidities such as depression and suicidal thoughts, are common in shoulder-related conditions. METHODS: Patients with atraumatic shoulder instability were recruited from a review of outpatient logbook and inpatient rehabilitation center admission records. Average and worst pain visual analogue scale rates were recorded for acute and chronic shoulder pain. Disability was measured using the “Disability of the Arm and Hand” score, as well as the Stanmore Percentage of Normal Shoulder Assessment (SPONSA). Depression was assessed using Becks Depression Inventory II, and further single psychological items were selected from other psychological assessment questionnaires. RESULTS: We included 64 patients, of which 51 (79.7%) were female. Mean visual analogue scale pain scores were in average 5.11 (standard deviation 2.24) and 5.58 (standard deviation 2.34) for acute and chronic shoulder pain, respectively. A stepwise, multiple linear regression revealed that only chronic shoulder pain remained significantly related to disability (F(1,61) = 46.13, P < .001). A second linear regression analysis was performed and showed a significant association between the overall Disability of the Arm, Shoulder and Hand score and overall Becks Depression Inventory score (F(1,62) = 12.78, P < .001). A further stepwise, multiple linear regression analysis indicated that chronic pain and depression remain independent variables in the prediction of disability. CONCLUSION: In addition to sociodemographic factors, pain and psychological comorbidities were found to have a negative impact on patient's functional outcome. This study further supports the need for an multidisciplinary team, holistic approach in the management of atraumatic shoulder instability patients with particular emphasis on chronic pain management and psychological support.