Glenohumeral Osteoarthritis: Current Concepts in Pathophysiology, Diagnosis and Management

Abstract

Glenohumeral osteoarthritis is a whole-joint disorder in which cartilage loss, subchondral bone remodelling, synovial inflammation, capsular fibrosis and altered glenohumeral mechanics interact to produce pain, stiffness and progressive loss of function. Its clinical expression is heterogeneous: radiographic severity does not map reliably onto symptoms, posterior glenoid erosion may evolve along distinct pathways, and associated rotator cuff or capsular pathology can change both diagnosis and treatment. This critical narrative review integrates current concepts in disease biology, clinical assessment, imaging and management, with particular attention to areas in which practice has moved faster than comparative evidence. Literature was selected through transparent searches of PubMed/MEDLINE and PubMed Central, supplemented by an authoritative professional guideline and backward citation searching of high-quality reviews. Evidence was appraised for study design, population selection, outcome validity, duration of follow-up, confounding and applicability. Plain radiography remains the initial imaging standard, whereas computed tomography with three-dimensional reconstruction is central to characterising glenoid version, bone loss and humeral head subluxation before arthroplasty. Non-operative care should be individualised and may include education, activity modification, analgesia, therapeutic exercise and injections, but high-certainty evidence for sustained benefit is limited. Arthroscopy can defer arthroplasty in selected younger patients, although durability declines in advanced incongruent disease. Anatomic total shoulder arthroplasty remains a highly effective option for cuff-intact, reconstructable anatomy and offers superior rotational motion, while reverse total shoulder arthroplasty has become an increasingly credible alternative for older patients, severe glenoid deformity, uncertain cuff durability or instability risk. Contemporary comparative studies suggest broadly similar short- to mid-term patient-reported outcomes, but they are predominantly non-randomised and vulnerable to selection bias. Treatment should therefore be based on symptoms, functional priorities, cuff status, bone morphology, biological age, complication tolerance and implant-specific trade-offs rather than radiographic grade alone. Major priorities include shoulder-specific disease phenotyping, standardised imaging measures, pragmatic non-operative trials and long-term comparative arthroplasty studies.