Exercise therapy in Knee Osteoarthritis

Marike van der Leeden PT PhD

1Amsterdam Rehabilitation Research Center | Reade

Osteoarthritis

Prevalence symptomatic OA in among adults aged ≥45 years

• Knee 16.7% • Hip 9.2%

Top 10 of most disabling diseases in European region Most important cause of pain and disability in the elderly

Jordan et al, 2007

WHO, 2008

Conaghan et al, 20082

Total joint failure

3

Bijlsma et al, Lancet, 2011

• Impairments of cartilage and bone• Findings on X-rays, MRI

Physical impairments• Muscle weakness, instability

• Sensory impairments• Pain, stiffness

• Limitations in activity and functioning• Walking, rising

• Problems in participation• Work

Osteoarthritis – multiple levels

4

Exercise therapy in knee OA

• Exercise is dominant intervention• Pain relieve• Improved performance of activities

• Exercise recommended in all major guidelinesFranssen, 2008, 2009

5

Definition and types of exercise

Definition: ‘a planned, structured and repetitively movement designed to improve or maintain one or more components of physical fitness’

Types of exercises: • Muscle strenghtening:

• strength: maximum amount of force a muscle can generate• endurance: ability of muscles to sutain muscle action

• Aerobic: improvement of aerobic capacity, eg walking, cycling• Flexibility: stretching exercises to increase ROM• Functional exercises: train problematic activities

6

Cochrane Review “Exercise for Osteoarthritis of the Knee”

Fransen M et al., January 2015

Evidence?

4

Objectives

Update of Cochrane review of 2008

‘To determine whether land-based therapeutic exercise is beneficial for people with knee OA in terms of reduced joint pain or improved physical function and quality of life’

5

Data collection and analysis

• A systematic review and meta-analysis was conducted

• Five databases were searched from their inception until May 2013

• Inclusion of all randomised controlled trials (RCTs) recruiting people with knee OA and comparing some form of land-based therapeutic exercise (as opposed to exercises conducted in the water) with a non-exercise or non-treatment (or waiting list) intervention were included (n =54)

6

Main results on pain

High-quality evidence from 44 trials (3537 participants) indicates that exercise reduced pain (SMD -0.49, 95% CI -0.39 to -0.59) immediately after treatment

Pain was estimated at 44 points on a 0 to 100-point scale (0 indicated no pain)in the control group; exercise reduced pain by an equivalent of 12 points (95% CI 10 to 15 points).

7

Moderate-quality evidence from 44 trials (3913 participants) showed that exercise improved physical function (SMD -0.52, 95% CI -0.39 to -.064) immediately after treatment

Physical function was estimated at 38 points on a 0 to 100-point scale (0 indicated no lossof physical function) in the control group; exercise improved physical function by an equivalent of 10 points (95% CI 8 to 13 points)

11

Main results on physical function

Treatment content

1210

Conclusion Cochrane review

High-quality evidence indicates that land-based therapeutic exercise provides short-term benefit in terms of reduced knee pain, and moderate-quality evidence shows improvement in physical function among people with knee OA.

The magnitude of the treatment effect would be considered moderate (immediate) to small (two to six months) but comparable with estimates reported for non-steroidal anti-inflammatory drugs.

13

Optimization of effectiveness

• Effects are small to moderate

• Optimization of effects through targeted exercise programs for specific subgroups

Targeted exercise therapy

Pain• Pain medication and exercise

Muscle weakness• Vitamin D, strength training

Comorbidity• Exercise adapted to comorbidity

Depressive mood and avoidance• Exercise plus graded increase of physical activity level

Instability of the knee joint• Proprioceptive exercise, strength training

15

Veenhof et al, Arthritis Care Res, 2006

Knoop et al, Osteoarthritis Cartilage, 2013

van Tunen et al, submitted

de Zwart et al, accepted

de Rooij et al, in progress

Stability trial

16

Muscle weakness

Laxity

Poor proprioception

Varus-valgus knee motion during walking

(In)stabilityknee

van der Esch et al,’06/’07

Activity limitations

Instability of knee joint: >60% of knee OA patients1,2

associated with activity limitations1,2

1 van der Esch et al, ’12; 2 Fitzgerald et al, ‘04

• 159 knee OA with knee joint instability: randomized

• 12 weeks with 2 sessions + home exercises;

• 6-8 patients per group, supervised by two pt’s;

• gradual increase in intensity and knee loading;

• exercises linked to daily activities;

• patients encouraged to remain physically active after treatment

Minimal intensity/loading Increasing intensity and loading

Muscle endurance

Week 1-4 Week 9-12Week 5-8

Week 1-8

Focus on muscle strengthening

Week 9-12

Focus on performance daily activities

Control program

Functional training + maximal strength + aerobic training

Exercise programs

Minimal muscle training + education

Minimal intensity/loading Increasing intensity and loading

Muscle endurance Functional training + maximal strength + aerobic training

Week 1-4

Focus on knee stabilization

Week 5-8

Focus on muscle strengthening

Week 9-12

Focus on performance daily activities

Experimental program

Knee stabilization training + education

Week 1-4 Week 9-12Week 5-8

Knee joint stabilization training

- feedback by PT’s- use of mirrors - specific exercises

Amsterdam Rehabilitation Research Center | Reade

Study design

•Randomized controlled trial (single-blinded)• two exercise programs.

•Inclusion criteria: • diagnosis of knee OA (ACR)• knee instability• age 40-75 years.

•Outcome measures: • WOMAC, physical function (primary)• NRS pain, GUG- test, global perceived effect, self-reported knee instability,

muscle strength, proprioception • measurements at baseline, 6-week (mid-treatment), 12-week (post-

treatment) and 38-week follow-up (6 months post-treatment)• assessor blinded for treatment allocation.

Amsterdam Rehabilitation Research Center | Reade

Flow chart

61% femaleage: 62 ± 7 yr69% K/L ≥ 2

Results (1)

Mean difference: B (95% CI) = -0.26 (-0.76-0.23)Mean difference: B (95% CI) = -0.01 (-2.58-2.57)

Primary outcome: WOMAC, physical function (0-68)

Secundary outcome: NRS knee pain (0-10)

• No difference in effectiveness between programs

Result on muscle strength

23

Result on knee stability

24

Results (2)

• Both exercise programs are highly effective and safe:• effect size: 0.9 for pain and 0.7-0.8 for function• effects unharmed after 6 months• no adverse events

• No added value of additional knee joint stabilization treatment, which is consistent with literature:

No differences between:• strength only vs. proprioceptive/balance + strength training (Diracoglu, ‘05)

• strength only vs. agility/perturbation + strength training (Fitzgerald, ‘11)

• strength only vs. neuromuscular + strength training (Bennell, ‘14)

Conclusion Stability trial (1)

Important role of muscle strength in knee stabilization:

a) Most important mechanoreceptors for proprioception located inside muscles: muscle spindles.

b) Self-reported knee instability associated with muscle weakness, while not with poor proprioception or high laxity (Knoop et al. Arthritis Care Res, 2012 Jan; 64(1)-38-45).

Conclusion Stability trial (2)

Implications for exercises

Exercising knee OA patients starts with muscle strengtening exercises (focus on quadriceps strength) and additional attention on knee joint stability

It seems that specific attention for knee stability is neccessarry in case of sufficient muscle strength or high laxity AND knee joint instability

18

Is the severity of knee OA on MRI associated with outcome

of exercise therapy?

Knoop et al, 2014

Background

• Effectiveness and safety of exercise therapy for OA patients with severe joint damage have been questioned

• Randomized clinical trial to compare two exercise programs (Knoop et al, Osteoarthritis Cartilage 2013)

• The two 12-week, supervised exercise programs (with/without knee stabilization training) were equally effective

• From the total group of (ranging from K/L grade 0-4), baseline MRIs were obtained in a random subsample (n=95)

Aim of study

To explore whether the severity of knee OA on MRI is associated with treatment outcome in knee OA patients treated with exercise therapy

Study sample (n=95)MRI features*

Cartilage loss:grade 0grade 1grade 2grade 3

7%8%31%54%

Bone marrow lesions:grade 0grade 1grade 2grade 3

17%25%27%31%

Osteophytes:grade 0grade 1grade 2grade 3

15%38%33%15%

MRI features*

Effusion:grade 0grade 1grade 2grade 3

34%30%23%13%

Synovitis:absentpresent

66%34%

Meniscal lesions:grade 0grade 1grade 2grade 3

7%13%22%58%

*highest regional grade per knee

MRI protocol:

• 3.0 Tesla MRI (GEMS)

• 5 sequences

• one index knee

• Boston Leeds Osteoarthritis Scoring (BLOKS) system, in which knee is subdivided into multiple regions; each region scored for severity of MRI-feature (Hunter et al, 2008).

Results (1/3)

• Outcome of exercise therapy independent of severity of knee OA in any MRI-feature

Example:

• With two exceptions

Results (2/3)

PF cartilage loss p=0.01 for WOMAC physical function

p=0.04 for upper leg muscle strength

Results (3/3)

PF osteophyte formation

p<0.01 for upper leg muscle strength

Conclusions

• First study to explore the role of OA severity on MRI in the effectiveness of exercise therapy

• Outcome of exercise therapy is independent of OA severity

• Only exception seems to be advanced PF OA, in which effects might be reduced; this needs replication for validation

Implications

• Referral to exercise therapy needs to be considered prior to total knee arthroplasty in patients with ‘end-stage’ knee OA

• Also in patients with severe knee OA, weightbearing intense exercises can be provided, if gradually increased and professionally supervised

Future research

Effects on inflammation

Exercise more effective in inflammatory phenotype of OA?

38

Summary

• Exercise therapy is effective to reduce pain and improve function

• Targeting exercise therapy to specific groups seems promising for patients with severe pain, comorbidities, and probably inflammation

• No added value of additional knee joint stabilization treatment in patients with knee instability

• Exercise therapy can be effective in all grades of OA severity

39

Questions:

m.vd.leeden@reade.nl