INTRODUCTION: There are no published studies that have investigated the occurrence of pain sensitization in patients with postoperative shoulder stiffness. The aim of this study was to describe the presence of pain sensitization and its association with risk factors in patients with shoulder stiffness following arthroscopic rotator cuff (RC) repair. METHODS: From 2016 to 2020, a total of 115 patients with shoulder stiffness after RC repair were consecutive and prospectively recruited. All patients completed the Pain Sensitivity Questionnaire (PSQ). Additionally, sociodemographic, comorbidities, anthropometrics, clinical (Tampa Scale of Kinesiophobia [TSK]) and functional outcomes measures (Constant-Murley [CM], Disabilities of the Arm, Shoulder, and Hand [DASH] questionnaires, and Visual Analog Scale [VAS]) were analyzed as baseline predictors
measurements were assessed at 6 weeks after surgery. RESULTS: A total of 75 patients (65.2%) showed pain sensitization. The results showed a positive association between higher values of PSQ-total and a high number of comorbidities (β=3.5
p<
0.001), higher values of body mass index (β=1.1
p=0.04), longer duration of symptoms (β=2.6
p<
0.001), high level of irritability (β=4.1
p=0.01), higher values on the TSK (β=4.1
p<
0.001), lower scores on the CM (β=1.4
p<
0.01), higher scores on the DASH (β=1.9
p<
0.001), and higher values on the VAS (β=4.2
p<
0.001). CONCLUSION: A high percentage of patients with shoulder stiffness following arthroscopic RC showed pain sensitization 6 weeks after surgery. Factors such as a high number of comorbidities, fear of movement and pain intensity are predictors of pain sensitization in these patients. Knowledge and understanding of risk factors should be used in the decision-making process for identification of risk factors for chronic pain after arthroscopic RC repair to enable better care of patients. LEVEL OF EVIDENCE: III.