Factors affecting shoulder joint range of motion after breast cancer surgery: a retrospective cohort study in Japan

Purpose: To evaluate factors influencing the range of motion (ROM) in shoulder flexion and abduction, which are often compromised by postoperative conditions, including pain, soft tissue damage, and muscle weakness, 1 month after breast cancer surgery in patients undergoing inpatient rehabilitation. Methods: In this retrospective study, the electronic medical database of a university hospital was searched for patients who underwent inpatient rehabilitation following breast cancer surgery between May 2014 and April 2020. The extracted data included age, sex, affected side, body mass index, number of nodes removed, levels of axillary lymph nodes, type of mastectomy, chemotherapy, radiation therapy, duration of postoperative drain placement, and length of hospital stay after the surgery. Passive shoulder joint ROM was examined before and 1 month after surgery. Multivariable logistic regression was performed to explore the prevalence of and factors associated with the presence of shoulder joint ROM limitations 1 month after surgery. Results: This study enrolled 258 patients. A total of 210 participants (81.4%) had shoulder ROM limitation after the surgery. Shoulder flexion and abduction ROM decreased after surgery by an average of 31.3° and 35.9°, respectively. Age, number of nodes removed, and total mastectomy were significantly associated with shoulder joint ROM limitation after surgery. Conclusion: Over 80% of participants had reduced shoulder ROM 1 month after surgery, even after inpatient rehabilitation. We identified age, number of nodes removed, and total mastectomy as risk factors for reduced shoulder ROM, providing useful prognostic information regarding the restriction of passive shoulder ROM after breast cancer surgery.