BackgroundPsychological symptoms are highly prevalent in patients with shoulder complaints. Psychological symptoms in patients with shoulder complaints might play a role in the aetiology, perceived disability and pain and clinical outcome of treatment. The aim of this study was to assess whether preoperative symptoms of distress, depression, anxiety and somatisation were associated with a change in function after shoulder surgery and postoperative patient perceived improvement of pain and function. In addition, the change of psychological symptoms after shoulder surgery was analyzed and the influence of postoperative symptoms of psychological disorders after surgery on the change in function after shoulder surgery and perceived postoperative improvement of pain and function.Methods and FindingsA prospective longitudinal cohort study was performed in a general teaching hospital. 315 consecutive patients planned for elective shoulder surgery were included. Outcome measures included change of Disabilities of the Arm, Shoulder and Hand (DASH) score and anchor questions about improvement in pain and function after surgery. Psychological symptoms were identified before and 12 months after surgery with the validated Four-Dimensional Symptom Questionnaire (4DSQ). Psychological symptoms were encountered in all the various shoulder diagnoses. Preoperative symptoms of psychological disorders persisted after surgery in 56% of patients, 10% of patients with no symptoms of psychological disorders before surgery developed new psychological symptoms. Preoperative symptoms of psychological disorders were not associated with the change of DASH score and perceived improvement of pain and function after shoulder surgery. Patients with symptoms of psychological disorders after surgery were less likely to improve on the DASH score. Postoperative symptoms of distress and depression were associated with worse perceived improvement of pain. Postoperative symptoms of distress, depression and somatisation were associated with worse perceived improvement of function.ConclusionsPreoperative symptoms of distress, depression, anxiety and somatisation were not associated with worse clinical outcome 12 months after shoulder surgery. Symptoms of psychological disorders before shoulder surgery persisted in 56% of patients after surgery. Postoperative symptoms of psychological disorders 12 months after shoulder surgery were strongly associated with worse clinical outcome.
Purpose
The pathophysiology of frozen shoulders is a complex and multifactorial process. The purpose of this review is to scope the currently available knowledge of the pathophysiology of frozen shoulders.
Methods
A systematic search was conducted in Medline, Embase and the Cochrane library. Original articles published between 1994 and October 2020 with a substantial focus on the pathophysiology of frozen shoulders were included.
Results
Out of 827 records, 48 original articles were included for the qualitative synthesis of this review. Glenohumeral capsular biopsies were reported in 30 studies. Fifteen studies investigated were classified as association studies. Three studies investigated the pathophysiology in an animal studies. A state of low grade inflammation, as is associated with diabetes, cardiovascular disease and thyroid disorders, predisposes for the development of frozen shoulder. An early immune response with elevated levels of alarmins and binding to the receptor of advance glycation end products is present at the start of the cascade. Inflammatory cytokines, of which transforming growth factor-β1 has a prominent role, together with mechanical stress stimulates Fibroblast proliferation and differentiation into myofibroblasts. This leads to an imbalance of extracellular matrix turnover resulting in a stiff and thickened glenohumeral capsule with abundance of type III collagen.
Conclusion
This scoping review outlines the complexity of the pathophysiology of frozen shoulder. A comprehensive overview with background information on pathophysiologic mechanisms is given. Leads are provided to progress with research for clinically important prognostic markers and in search for future interventions.
Level of evidence
Level V.
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