Inclusion Criteria:

• Adult subject 18 years or older.
• Scapula and proximal humerus must have reached skeletal maturity.
• Clinical indication for reversed TSA due to: non-inflammatory degenerative joint disease (i.e., osteoarthritis), avascular necrosis, pseudoparalysis or anterior superior escape, functional deformity, post-traumatic arthritis, and/or rotator cuff tear arthropathy.
• Willing and able to comply with the protocol.
• Willing and able to sign the informed consent form.
• Patients with an adjusted Constant Score ≤ 65.

Exclusion Criteria:

• Active local or systemic infection, sepsis, or osteomyelitis.
• In the opinion of the clinician, there is inadequate bone stock in the proximal humerus or glenoid fossa for supporting the components.
• In the opinion of the clinician, there is poor bone quality where there could be a considerable migration of the prosthesis and/or a chance of fracture of the humerus or glenoid.
• In surgeon’s opinion, rotator cuff tear requires a latissimus dorsi transfer.
• In the clinician’s opinion, the subject is unwilling or unable to be compliant with the recommendations of the healthcare professional.
• Metabolism disorder that could compromise bone formation, or Osteomalacia.
• Rapid destruction of the joint, marked bone loss, or bone resorption apparent on imaging.
• Known allergy or suspected allergy to the materials.
• Female subjects who are pregnant or planning to become pregnant within the study period.
• Medical condition(s) or balance impairments that could lead to falls (e.g., epilepsy not well-controlled with medication, Multiple Sclerosis, etc).
• Previous failed arthroplasty.
• Nonfunctional deltoid muscle.
• Neuromuscular compromise condition of the shoulder (e.g., neuropathic joints or brachial plexus injury with a flail shoulder joint).
• Known active metastatic or neoplastic disease, Paget’s disease or Charcot’s disease.
• Currently, or within the last six months, or planning to be on chemotherapy or radiation.
• Recent or ongoing alcohol or drug abuse as determined by the investigator.
• Taking > 5mg/day corticosteroids (e.g., prednisone), excluding inhalers and one-time injections, within three months before surgery.
• Currently enrolled in any clinical research study that might interfere with the current study.
• Known history of severe depression.
• Primary insurance is Workers’ Compensation.
• The study has completed 109 implant attempts for the randomized treatment arm.
• Sequela of proximal humerus trauma requiring greater tuberosity osteotomy during RSA.
• Chronic shoulder dislocation with or without fracture, > 6 weeks.
• Parkinson’s disease.

Eligibility last updated 1/21/22. Questions regarding updates should be directed to the study team contact.