What is end-stage knee osteoarthritis? A scoping and narrative review

The term 'end-stage knee osteoarthritis (OA)' was explored with combined scoping and narrative review methodology to identify and critique definitions and current practice usage.

Medline and 16 relevant websites were searched for the term 'end-stage (knee) osteoarthritis'. Extracted text-based data were analysed with an inductive qualitative content analysis method and discussed in relation to contemporary understanding of knee OA.

From 130 resources, the term was almost universally used to mean eligible for surgery. Analysis of the 20 definitions identified the themes: (1) Radiographic evidence approach (based on joint imaging), (2) Clinical criteria or symptom burden approach (incorporated symptom and function experiences), (3) Surgical indication (term used synonymously to mean surgery is needed), and (4) Integrated radiographic and clinical algorithm (radiographic and clinical dimensions combined in a decision rule). Total knee arthroplasty was frequently reported as the 'gold standard' treatment. Pain and function can improve in people with end-stage OA and non-surgical treatment options are available.

Our review identified limited definitions. The term is often used in a way that is inconsistent with actual patient experiences. That is, 'end-stage' is not necessarily the 'end'. Our recommendations include using different terminology in clinical practice (e.g., using 'surgical threshold' to mean when the person becomes eligible to consider surgery), and recognising the right time for surgery is complex and individual given the multidimensional and variable nature of the OA experience. For determining research study eligibility, we recommend using specific tools to measure clearly defined constructs.