Epidemiology and prognosis of osteoarthritis 111 Joost Dekker PhD Department of Rehabilitation Medicine & Department of Psychiatry VU University Medical Center, Amsterdam, Netherlands

Contents Definitions Prevalence, Incidence Prognostic factors for development of OA Course and prognosis of activity limitations in OA 2

Definitions Radiographic OA –Kellgren – Lawrence grading –KL ≥ 2 (KL ≥ 1) 3

Kellgren & Lawrence grading 0 - No radiographic features of osteoarthritis 1 - Possible joint space narrowing and osteophyte formation 2 - Definite osteophyte formation with possible joint space narrowing 3 - Multiple osteophytes, definite joint space narrowing, sclerosis and possible bony deformity 4 - Large osteophytes, marked joint space narrowing, severe sclerosis and definite bony deformity 4

Definitions Radiographic OA –Kellgren – Lawrence grading –KL ≥ 2 (KL ≥ 1) Symptomatic OA –Radiographic + symptoms (pain, stiffness) Clinical OA –Symptoms –American College of Rheumatology (ACR) criteria –Knee pain in older people Activity limitations in OA 5

Prevalence and Incidence 6

7 Suri et al, PM&R, 2012

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Prognostic factors for development of OA (radiographic, symptomatic) 9

10 Suri et al, PM&R, 2012

Suri, Morgenroth and Hunter, PM&R, 2012 Figure 1: Potential risk factors Narrative review Evidence for some risk factors for incidence/progression of OA –Age, gender, overweight/obesity –Joint injury, limb-length inequality, alignment, hip dysplasia Evidence for other risk factors less clear 11

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Silverwood et al, 2015 Meta-analysis 13

Silverwood et al, 2015 Systematic review –Overweight, obesity –Previous knee injury –Female gender –Age –Occupational factors (see also Ezzat et al, Physiotherapy Canada, 2014) –Intense physical activity 14

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Risk factors for the development of OA (radiographic, symptomatic) Evidence from meta-analyses and systematic reviews –Systemic factors : Age, gender, overweight/obesity –Local factors: Joint injury, limb-length inequality, alignment, hip dysplasia, occupational factors, intense physical activity, muscle weakness Rapid developments –Evidence will change 16

Course and prognosis of activity limitations 17

Course of activity limitations Highly variable Worse, stable and better functioning 18 Dekker, 2009

Course of activity limitations in early knee OA Holla et al,

Characteristics of the subgroups Subgroup 2 (‘moderate outcome’) compared with Subgroup 1 (‘good outcome’) –Higher BMI –Greater knee pain, hip pain –Less vitality/more fatigue –≥3 comorbidities Subgroup 3 (‘poor outcome’) compared with Subgroup 1 (‘good outcome’) –Younger age –Greater knee pain, hip pain –Bony tenderness, lower range of active knee flexion, osteophytosis –Less vitality/more fatigue –Resting/avoidance of activity –≥3 comorbidities 20

Prognosis of pain and physical functioning in knee OA - Systematic review Strong evidence on –Knee characteristics –worsening in radiographic osteoarthritis –bilateral knee symptoms –higher knee pain at baseline –worsening of knee pain –pain on patella-femoral joint compression –lower knee extension strength Strong evidence on –Clinical factors –lower walking speed –more disability –higher morbidity count –poor general health –Psychosocial factors –lower vitality –poor mental health –more depressive symptoms. 21 de Rooij et al, submitted

Summary Radiographic OA, Symptomatic OA, Clinical OA, Activity limitations in OA Risk factors for the development of OA (radiographic, symptomatic) –Systemic factors : Age, gender, overweight/obesity –Local factors: Joint injury, limb-length inequality, alignment, hip dysplasia, occupational factors, intense physical activity, muscle weakness Activity limitations in OA –Highly variable –Knee characteristics, clinical factors, psychosocial factors 22