Press-Fit vs Loose-Fit Radial Head Arthroplasty

Inclusion Criteria:

1. Age 18 years or older.
2. Scheduled for primary RHA.
3. Willing and able to provide written informed consent.
4. Willing and able to comply with post-operative follow-up visits at 3 months, 6 months, 1 year, and 2 years.
5. No concurrent elbow procedures such as ligament reconstruction or additional joint resurfacing at the time of RHA.
6. No prior history of revision RHA.
7. RHA to be performed using press-fit or loose-fit implants (no other fixation methods included).
8. Must be able to complete PROs independently.

Exclusion Criteria:

1. Diagnosed with any significant comorbidities that could interfere with rehabilitation or study participation, including but not limited to:

   * Severe osteoarthritis affecting elbow function
   * Rheumatoid arthritis or other autoimmune disorders affecting musculoskeletal function
   * Full-thickness cartilage lesion in the elbow joint
   * Neurological or vascular complications
   * Neuromuscular disorders affecting movement or coordination
   * Neurocognitive conditions impacting study participation
   * Chronic infections or immunodeficiency conditions
   * Uncontrolled diabetes
   * Cardiovascular diseases (e.g., congestive heart failure, ischemic heart disease)
   * Severe chronic obstructive pulmonary disease (COPD) or other significant respiratory conditions
   * Renal insufficiency or chronic kidney disease (stage 3 or higher)
   * Obesity with a body mass index (BMI) \> 40
   * Active cancer treatment or history of cancer within the past 5 years
2. Known allergy or contraindication to any surgical materials used in the radial head implant procedure.
3. Patients currently participating in another clinical trial that may interfere with this study's outcomes.
4. Risk factors for poor implant integration and healing, including:

   * Active alcohol or substance dependence
   * Nicotine/tobacco use
   * Chronic corticosteroid use
   * Recent chemotherapy
5. Any condition that, in the opinion of the principal investigator, would make participation in the study unsafe or not in the patient's best interest.