Comparison Between Exactech Guided Personalized Surgery (GPS) and Conventional Instrumentation of Shoulder Arthroplasty

Primary outcomes

• SST-12 [Through study completion, an average of 1 per year]: Shoulder Simple Test (SST) - 12 questions with yes/no responses that measure shoulder pain and function from a patient's perspective - 12 yes corresponds to 100%
• SPADI [Through study completion, an average of 1 per year]: Shoulder Pain and Disability Index (SPADI) -13 questions assessing about pain scale (5 questions) and disability scale (8 questions) where 0 indicates no pain/no difficulty and 10 indicates worst pain imaginable/so difficult it requires help while performin these activities
• Constant [Through study completion, an average of 1 per year]: Constant Shoulder Score - 100 points scale about pain, Activities of daily living, Strength test, and Range of Motions questions about shoulder where 100 % corresponds to the highest pain
• ASES [Through study completion, an average of 1 per year]: American Shoulder and Elbow Surgeons Score (ASES) - 100 points scale about shoulder pain and performance evaluation in activities of daily living where 100 indicates the best shoulder condition
• UCLA [Through study completion, an average of 1 per year]: University of California Los Angeles Shoulder Score (UCLA) - 5 Items score which combines both physician (3 items) and patient assessment (2 items) whith a total range from 0-35 where 0 indicates worse shoulder function and 35 better shoulder function outcomes

Sex: All, ages: 21 Years to any

Inclusion Criteria:

* Patient is at least 21 years of age at the time of surgery
* Patient is indicated for reverse shoulder arthroplasty
* Patient is willing to participate by complying with pre- and postoperative visit requirements
* Patient is willing to participate for the entire length of the prescribed follow-up (minimum 2 years)
* Patient is willing and able to review and sign a study informed consent form
* Preop CT scan is within 3 months of the date of surgery

Exclusion Criteria:

* Revision shoulder arthroplasty
* Reverse shoulder arthroplasty for fracture
* Need for structural glenoid bone graft
* Osteomyelitis of the proximal humerus or scapula; if a systemic infection or a secondary remote infection is suspected or confirmed, implantation should be delayed until infection is resolved
* Inadequate or malformed bone that precludes adequate support or fixation of the prosthesis
* Neuromuscular disorders that do not allow control of the joint
* Significant injury to the brachial plexus
* Non-functional deltoid muscles
* The patient is unwilling or unable to comply with the post-operative care instructions
* Patients who are a known drug or alcohol abuser, or have a psychological disorder (e.g. schizophrenia major depression, bipolar disorder, etc.) as defined by the DSM4 that affect follow-up care or treatment outcomes.
* Alcohol, drug, or other subtance abuse
* Any disease state that could adversaly affect the function or longevity of the implant
* Patient is pregnant
* Patient is a prisoner
* Patient who are currently involved in any personal injury litigation, medical-legal or worker's compensation claims

• Robert J Hillen, MD, Principal investigator, Dijklander Ziekenhuis
• Ron Onstenk, MD, Principal investigator, Groene Hart Ziekenhuis