OsseoFit Stemless Shoulder System (Anatomic)

The purpose of this clinical research protocol is to evaluate the safety, efficacy, and long-term outcomes of the OsseoFit Stemless Shoulder System (Anatomic) in patients with a primary diagnosis of osteoarthritis. The study aims to assess the intraoperative characteristics, postoperative complications, functional outcomes, and radiographic findings associated with the use of the stemless implant system. Ultimately, this research aims to improve patient outcomes, enhance surgical techniques, and inform clinical decision-making in the treatment of shoulder pathology.

The objectives of this study are to confirm the safety, performance, and clinical benefits of the OsseoFit Stemless Shoulder System (implants and instruments) in primary total shoulder arthroplasty (anatomic). Safety of the system will be assessed by monitoring the frequency and incidence of adverse events. The performance and clinical benefits will be evaluated by assessment of the overall pain and functional performance, survivorship, quality of life, and radiographic parameters for all enrolled study participants. The primary endpoint is the improvement in the American Shoulder and Elbow Surgeons (ASES) Shoulder score between the pre-operative period (baseline) and 2 years of follow up. The key secondary endpoint is the survival of the implant system at 10 years, which is based on removal of any part of the study device and will be determined using Kaplan Meier method. The safety of the system will be assessed by monitoring the frequency and incidence of adverse events. The secondary endpoint evaluation will also assess the overall pain/functional performance (ASES, Constant Murley Shoulder Score, and ROM), quality of life, satisfaction, and radiographic parameters of all enrolled study participants.

Inclusion Criteria: * Patient must be 20 years of age or older. * The patient must be anatomically and structurally suited, as evident by scapula and proximal humerus closure, to receive the implants. * Patient planned to receive OsseoFit™ anchor with uncemented fixation. * Patient planned to receive a Modular Alliance Glenoid with bone cement. The porous posts must be coated with Porous Plasma Spray (PPS) and may be inserted without bone cement. * Patient planned to receive shoulder arthroplasty due to osteoarthritis. * Patient must be able and willing to complete the protocol required follow-up schedule. * Patient must be able and willing to sign the IRB approved consent. Exclusion Criteria: * Patient is unwilling or unable to give consent or to comply with the follow-up program. * Patient has any condition which would in the judgement of the Investigator, place the patient at undue risk or interfere with the study. * Patient is known to be pregnant or breastfeeding. * Patient is a vulnerable participant (prisoner, mentally incompetent or unable to understand what participation to the study entails, a known alcohol or drug abuser, and/or anticipated to be non-compliant). * Patient is uncooperative or patient with neurologic disorders who is incapable or unwilling to follow directions. * Patient has any neuromuscular disease compromising the affected limb. * Patient has any sign of infection affecting the shoulder joint or in its proximity which may spread to the implant site. This may include: * Local/systemic infection * Sepsis * Osteomyelitis * Patient presents with Osteomalacia. * Patient presents with a humeral bone fracture. * Patient presents with malunion or non-union of the tuberosities of the proximal humerus. * Patient has had a previous operative shoulder prosthesis (stem or stemless). * Patient has irreparable cuff tear. * Patient presents with inadequate humeral bone, which in the opinion of the Investigator, may lead to poor implant fixation. This may include but is not limited to: * Osteoporosis * Extensive Avascular Necrosis * Rheumatoid Arthritis * Metaphyseal bony defects (including large cysts)