Reluctant knee: understanding and managing stiffness after total knee arthroplasty

Purpose Post-total knee arthroplasty (TKA) stiffness remains a clinically important cause of pain, restricted range of motion (ROM), functional limitation, and reintervention. This narrative review synthesises current evidence on the pathophysiology, evaluation, and staged management of post-TKA stiffness, with particular emphasis on manipulation under anaesthesia (MUA). Methods A narrative review was performed using literature relating to post-TKA stiffness, arthrofibrosis, diagnostic evaluation, rehabilitation, MUA, lysis of adhesions, and revision TKA. Evidence was synthesised thematically to support a practical diagnostic and management framework. Results Acquired idiopathic stiffness occurs in approximately 3.6% to 4.0% of TKAs, while MUA is required in roughly 2.6% to 3.6% of cases. The available literature supports a diagnosis-of-exclusion approach, in which infection, component malposition, instability, and other secondary causes are excluded before arthrofibrosis is diagnosed. MUA remains the principal first-line procedural intervention once early conservative measures fail. Earlier MUA, generally within 6–12 weeks, is associated with greater ROM gain than delayed intervention, although outcomes remain influenced by baseline ROM severity, patient selection, and the quality of post-manipulation rehabilitation. Conclusion Post-TKA stiffness is a heterogeneous complication requiring structured evaluation and staged management. When MUA fails, escalation to arthrolysis or revision TKA should be individualised and guided by the distinction between persistent soft-tissue fibrosis and correctable mechanical pathology. A practical algorithm is proposed to support diagnosis, timing of intervention, and escalation after failed MUA.