Primary shoulder stiffness

Primary shoulder stiffness manifests as shoulder pain accompanied by a progressive loss of both active and passive range of motion. It typically affects people in their fourth to sixth decades of life and shows a slight female predominance. Metabolic and endocrine comorbidities, particularly diabetes mellitus, dyslipidemia, and hypothyroidism, are considered as risk factors and are linked to protracted courses and reduced responsiveness to treatment. From a pathobiological perspective, the disease represents a fibroinflammatory process of the capsule, characterized by synovial inflammation, new vessel formation, myofibroblast proliferation, excessive matrix deposition, upregulation of proinflammatory and profibrotic mediators, and a disturbed MMP/TIMP-mediated matrix turnover. The clinical course typically follows a stage-like dynamic (pain, movement restriction, and recovery: freezing, frozen, thawing, lasting between 12 to 42 months), with spontaneous improvements possible but not guaranteed and residual rotation deficits possibly persisting. Diagnosis relies principally on history and physical examination; imaging mainly aids differential diagnosis and may show typical but not pathognomonic findings. Treatment is phase-adapted according to the dominant pathophysiology: early stages prioritize pain control and anti-inflammatory measures, while later stages focus on restoring capsular distensibility. Conservative management remains central in treating primary shoulder stiffness, with physiotherapy, especially when combined with manual therapy, stretching, and home exercise, playing a key role in reducing pain and restoring mobility. Nonsteroidal anti-inflammatory drugs and corticosteroids, administered orally or via intra-articular injection, can provide notable short-term relief, with intra-articular corticosteroid injections being currently considered the gold standard treatment for their effectiveness during the inflammatory stage and fewer potential side effects. This review summarizes the current state of knowledge and offers consensus-based, practical diagnostic and treatment recommendations.