Non-adherence to pain medication increases risk of postoperative frozen shoulder

Background: Postoperative frozen shoulder (FS) or adhesive capsulitis is a relatively frequent complication (5-20%), even after simple arthroscopic shoulder surgeries. The pathophysiology is still unclear, but psychological factors may play a pivotal role. From clinical experience, we hypothesized that patients, who are reluctant to take medications, particularly “pain-killers,” have an increased incidence of postoperative FS. Methods: We identified twenty patients who underwent limited arthroscopic operations of the shoulder and developed postoperative FS. Twenty patients with matching type of surgery, age, and gender served as control group (n = 20). All patients were at least one year postoperative and asymptomatic at the time of examination. Demographic data, the patient's adherence to self-medication (including self-medicating scale, SMS), development the Quality of life (QoL), and depression scale (PHQ-4-questionnaire) were assessed. Results: Patients with FS had a 2-fold longer rehabilitation and 3-fold longer work inability compared to the patients without FS (P