This prospective blinded study aims to investigate the relationship between objectively measured sleep parameters and patient-reported sleep and functional outcomes in patients undergoing reverse shoulder arthroplasty. Sleep will be assessed using MotionWatch 8, and outcomes will be correlated with validated clinical scores. This study is designed as a prospective, blinded clinical investigation conducted at a single tertiary referral center. Patients undergoing reverse shoulder arthroplasty for cuff arthropathy or glenohumeral osteoarthritis will be consecutively enrolled.

Objective sleep parameters will be collected using MotionWatch 8 one week prior to surgery in the patients' home environment. Functional and subjective sleep assessments will be performed preoperatively using validated scoring systems including ASES, Constant-Murley Score, VAS, SST, PSQI, and Jenkins Sleep Scale.

Postoperative follow-up will include reassessment of functional scores at 1, 3, and 6 months. At the 6-month follow-up, both subjective sleep assessments and objective sleep measurements will be repeated.

The primary objective is to evaluate the correlation between objective sleep parameters and ASES and PSQI scores.

Inclusion Criteria:

Patients undergoing reverse shoulder arthroplasty Diagnosis of cuff arthropathy or glenohumeral osteoarthritis Age ≥18 years Ability to provide informed consent

Exclusion Criteria:

Refusal to participate Known psychiatric disorders Pre-existing diagnosed sleep disorders or ongoing treatment for sleep disturbances Pathology affecting the contralateral shoulder Inability to comply with study protocol

Adult patients undergoing reverse shoulder arthroplasty for cuff arthropathy or glenohumeral osteoarthritis at a single tertiary referral center will be included. All participants will be consecutively recruited and treated by the same experienced surgeon using a standardized surgical technique and implant system.

The study population consists of patients without diagnosed sleep disorders or psychiatric conditions, who are able to complete patient-reported outcome measures and comply with home-based sleep monitoring using actigraphy (MotionWatch 8).