Shoulder Arthritis: AI-Powered Imaging Analysis

Primary glenohumeral osteoarthritis shows characteristic findings on X-ray and MRI: joint space narrowing, subchondral sclerosis, osteophytes at the inferior humeral head and glenoid, and posterior glenoid erosion with posterior humeral head subluxation (the Walch classification). Rheumatoid arthritis presents with symmetric joint space loss, periarticular erosions, and osteopenia without large osteophytes. Rotator cuff arthropathy is characterized by superior migration of the humeral head, acetabularization of the acromion, and femoralization of the humeral head due to chronic massive rotator cuff tear. Post-traumatic arthritis can show irregular joint surfaces, hardware from prior surgery, and malunion deformity. MRI additionally demonstrates cartilage thickness and rotator cuff integrity, critical for surgical planning.

Preoperative MRI provides information not available on plain radiographs that directly impacts implant selection and surgical technique. Assessment of rotator cuff integrity on coronal-oblique and axial T2-FS sequences determines whether an anatomic total shoulder arthroplasty (requiring intact rotator cuff) or a reverse total shoulder arthroplasty (suitable for cuff-deficient shoulders) is appropriate. Glenoid morphology and version are evaluated on axial images to guide glenoid component positioning and the need for bone grafting. The degree of posterior glenoid erosion and humeral head subluxation on axial sequences helps quantify deformity correction required. Muscle quality of the rotator cuff, deltoid, and periscapular muscles informs rehabilitation prognosis.

Conservative management of glenohumeral arthritis includes NSAIDs for analgesic and anti-inflammatory effect, activity modification to avoid high-impact loading, and physical therapy to maintain range of motion and strengthen periarticular musculature. Intra-articular corticosteroid injections provide temporary relief lasting weeks to months and may be repeated two to three times per year. Viscosupplementation with hyaluronic acid is used off-label by some practitioners, though evidence for glenohumeral arthritis is less robust than for the knee. Platelet-rich plasma injections are under investigation. Total shoulder or reverse shoulder arthroplasty is the definitive treatment for end-stage arthritis refractory to non-surgical measures, with excellent pain relief and functional outcomes.