Knee OA

Evaluation of treatment with orthotics

(wedged insole and knee brace)

Preliminary data

Kjell G Nilsson, MD, PhD, FRACSJan Karlsson, CPO

Department of OrthopaedicsUmeå University hospital

Umeå, Sweden

Implant Research Unit

Osteoarthrosis (OA) OA is a very common disease More common than diabetes and heart diseases Incidence increases with age However, common even in younger patients

• approx 5 % between 35 och 54 years have OA

30 40 50 60 70 800

10

20

30

40

50

60

70

80

90

Age

Hip OA

Knee OA

Finger OA

Prevalence of OA (%)

Implant Research Unit

OA

Cost for the society (Sweden 2002)• Direct costs (drugs and treatmenmt)

– 2 billion SEK

• Sick leave and loss of income and loss of production

– 10 billion SEK

Symptoms of OA at the knee

Often insidious onset

Stiffness

Decreased mobility and range of motion

Crepitations

Pain with activity

Swelling

Tenderness

Pain at rest

Deformity

Implant Research Unit

Treatment of OA

Few

Some

All

?

Treatment of knee OA with orthotics

• Wedged insole (keel)• Brace

Suggested function:• Reduce the load on the concave side of the deformity

during weight bearing (“dynamic unloading”)

reduce pain

Wedged insole

Suggested function Reduce the load (varus moment) lateral keel reduce pain

Suggested function

Reduce the load

(varus moment)

keel + valgusbrace

(three point pinciple)

reduce pain

Wedged insole + brace

Treatment of knee OA with orthotics

• Several studies have shown biomechanical effects of wedged insoles and knee braces

But

• What about their clinical effects??

Questions

• What are the effects (if any) (as measured by KOOS) of– 1. Wedged insole (keel) only– 2. Wedged insole (keel) + varus or valgus brace

• Do all patients require brace? Or is insole sometimes enough?

• Are there gender differences?• Are there age differences?

Knee Injury and Osteoarthritis Outcome Score (KOOS)• A knee specific instrument• Consists of 5 subscales

– 1. Pain 9 questions– 2. Other symptoms 7 questions

» (swelling, joint movement, mechanical symptoms)

– 3. Function in daily living (ADL) 17 questions– 4. Function in sports and recreation 5 questions– 5. Knee related Quality of Life (QoL) 4

questions• Each answer alternative is scored 0 to 4

Roos, Lohmander et al, Health Qual Life Outcomes 2003:1:64Roos, Roos, Lohmander et al, Scand J Med Sci Sports 1998:8:439Roos, Roos, Lohmander et al, J Orthop Sports Phys Ther 1998:28:88

KOOS

• All scores for each subscale are summarized and thereafter normalized to a 0-100 scale– 0 extreme knee symptoms– 100 no knee symptoms

• A total score for all 5 subscales is NOT calculated

KOOS

• Change over time “Effect Size”

(After – Before)/SD (Before)

Before treatment

After treatment

After

Before

Arthroplasty ACL reconstr Meniscectomy ACI

0.0

0.5

1.0

1.5

2.0

2.5

3.0

painsymptomsADLSportsRecrQoL

Effect size, examples

Present Study

1. Initially, offer all patients a laterally or medially wedged insoleFollow up minimum 6 weeks

2. For those who are unsatisfied with insole, offer a knee brace in addition to insoleFollow up minimum 6 weeks

3. (Plan: Continued follow up of all patients > 5 years)

Patient logistics (1)

• Referred from the Orthopaedic Department• Medial or lateral OA as confirmed by X ray• Clinical symptoms of OA• No inflammatory arthritis

• For various reasons not ready for surgery– (Too young, too old, too infirm, not mentally ready for

surgery, want to try conservative treatment before accepting operation, etc…)

Methods (1)

• 1. After receiving the referral– Information letter and 1st KOOS questionnaire sent to the patient– KOOS form to be filled out before first visit

• 2. First visit– 1st KOOS form collected (i.e. PRE treatment form)– Repeat information about the study– 10 degree laterally or medially wedged insole (keel) given to all

patients– 2nd KOOS form given, to be sent back after ≥ 6 weeks of insole/keel

treatment (i.e. keel/insole form)– Asked to indicate after 6 weeks if insole/keel treatment is sufficient

or insufficient

Methods (2)

• Second visit (for those patients who felt insole/keel treatment was insufficient)– All these patients received a varus or valgus brace to be used in

addition to the wedged insole/keel– Given a 3rd KOOS form (insole/keel-brace form) to be filled in after ≥

6 weeks of treatment with insole/keel + brace treatment

Patient logistics (2)

136 referralsreceived

120 KOOS formscorrectly filled out

90 KOOS formsreceived after 6 weeks

treatment with insole/keel

Insole/keel treatment

56 patients satisfiedwith insole/keel

treatment

34 patients NOT satisfiedwith insole/keel treatment

Addition ofbrace

34 KOOS forms received after 6 weeksof insole/keel treatment

Patients

• N = 90, mean age 58 y– 47 men (mean 56 y)– 43 women (mean 60 y)

• (Bilat OA n=19) - (10 men, 9 women)

• Medial – (38 men, 36 women)

• Lateral OA n=16 (18%) - (9 men, 7 women)

Inlay sole:10° laterally or medially based keel

Braces used

Custom CarbonFibre

1 patient

DonJoy (11-0872)

1 patient

Camp (Breg 0700, Breg 25262)

8 patients

Custom, DonJoy, Camp

• Difficult to adjust to the patients• Felt by the patient to be “bulky”• Relatively small pads for soft tissue pressure

• Abandoned after 10 patients

Össur Unloader One

24 patients

Össur Unloader One

• Large pads for soft tissue contact and pressure• Easy to adjust to the individual patient• Easy to apply and remove• Easily accepted by the patient

• Therefore used in the majority of the patients (the last 24)

Preliminary data

Effect of a wedged insole

Pain Symptoms ADL Sports QoL

100

80

60

40

20

0

Pre

Keel

0.05 ns ns ns 0.003

Insole/Keel (90 patients)

Paired t test

Mean values ± 95% CI

Pain Symptoms ADL Sports QoL

100

80

60

40

20

0

Pre

Keel

ns ns ns ns ns

Insole/Keel(women)

Paired t test

Mean values ± 95% CI

Pain Symptoms ADL Sports QoL

100

80

60

40

20

0

Pre

Keel

0.01 ns ns ns 0. 002

Insole/Keel(men)

Paired t test

Mean values ± 95% CI

Summary: Effects of Insole/Keel

• Some improvement in total material

– Effect size 0.10 (symptoms) to 0.31 (QoL)

• Smaller effect in women– Effect size 0.05 (symptoms) to 0.27

(QoL)

• Larger effect in men– Effect size 0.10 (symptoms) to 0.55

(QoL)

Keel all Keel women Keel men

0.0

0.2

0.4

0.6

0.8

1.0

painsymptomsADLSportsRecrQoL

Pain Symptoms ADL Sports QoL

100

80

60

40

20

0

Men Pre

Men Keel

Women Pre

Women Keel

Women vs menw and w/o insole/keel

0.02 0.006 0.04 0.17 0.45Women keel vs men keel

0.17 0.004 0.09 0.11 0.81Women pre vs men pre

Un-paired t test

Effects of insole/keel and age

Pain Symptoms ADL Sports QoL

100

80

60

40

20

0

Pre

Keel

ns ns ns ns ns

Insole/Keel(age < 60 years)

Paired t test

Mean values ± 95% CI

Pain Symptoms ADL Sports QoL

100

80

60

40

20

0

Pre

Keel

0.04 ns 0.04 ns 0.001

Insole/Keel(age > 60 years)

Paired t test

Mean values ± 95% CI

Summary: Effects of Insole/Keel and Age

• Small effect in the young (< 60 years)

– Effect size 0.00 (symptoms) to 0.17 (sports/recr)

• Larger effect in the elderly (> 60 years)

– Effect size 0.19 (sports/recr) to 0.64 (QoL)

Keel young Keel old

0.0

0.2

0.4

0.6

0.8

1.0

painsymptomsADLSportsRecrQoL

Results after 6 weeks of insole/keel

• 56 patients were satisfied• 34 patients were dissatisfied

• Question: • Was there a difference in KOOS between those groups?

Pain Symptoms ADL Sports QoL

100

80

60

40

20

0

Satisfied vs dissatisfied after 6w with insole/keel

56 Satisfied with keel

34 Dissatisfied with keel

0.02 0.28 0.08 0.71 0.02 Un-paired t test

Effects of insole/keel and brace

Pain Symptoms ADL Sports QoL

100

80

60

40

20

0

Pre

Keel + orthosis

0.9 0.02 0.048 0.04 0.01

Keel + Brace (34 patients)

Paired t test

Mean values ± 95% CI

Pain Symptoms ADL Sports QoL

100

80

60

40

20

0

Pre

Keel + orthosis

0.29 0.32 0.30 0.53 0.54

Keel + Brace (34 patients)

Effect Size:

Summary: Effects of Keel and Brace

• Significant improvement of all 5 subscales of KOOS– Effect size 0.29 (pain) to 0.54 (QoL)

Effects of keel and braceand age

Pain Symptoms ADL Sports QoL

100

80

60

40

20

0

Pre

Keel + orthosis

0.04 0.01 0.01 0.01 0.002

Keel + Brace (< 60 years)

Paired t test

Mean values ± 95% CI

Pain Symptoms ADL Sports QoL

100

80

60

40

20

0

ns ns ns ns ns

Pre

Keel + orthosis

Keel + Brace (> 60 years)

Paired t test

Mean values ± 95% CI

Keel+Brace young Keel+Brace old

0.0

0.2

0.4

0.6

0.8

1.0

painsymptomsADLSports/RecrQoL

Summary: Effects of Keel and Brace and Age• Highly significant

improvement in all 5 subscales in younger patients (< 60 y)

– Effect size 0.45 (symptoms) to 0.87 (sports/recr)

• No significant effect in older patients (>60 y)

– Effect size -0.27 (sports/recr) to 0.12 (symptoms)

Keel+Brace old

Effect size, examples

MeniscectomyKeel old

Keel youngKeel+Brace old

Keel+Brace young

0.0

0.2

0.4

0.6

0.8

painsymptomsADLSportRecrQoL

Keel+Brace old

Effect size summary

Discussion (1)

• This study shows that orthotics indeed are effective in treating OA

• There was improvement in every domain/subscale of KOOS with treatment

• However, it seems that there are differences in the results, not at least as regards the age of the patient

Discussion (2)

• A wedged insole (keel) can be used to start treatment– Easy– Cheap– Sufficient for > 50% of the patients (56 of 90)– Especially for elderly patients– Effect size in elderly similar to meniscectomy

Discussion (3)

• If a wedged insole is insufficient, addition of a brace is beneficial, provided the patient is younger

• Effect size in the younger patient larger than for meniscectomy

Discussion (4)

• As in other studies of patients with symptoms of OA, female patients score lower values for all items of the KOOS questionnaire

Discussion (5)

So far unanswered questions:• How long will the improvement last?• Differences among insole only compared to insole+brace?• Will the patients continue to use their insoles/braces• What about compliance?• How many of these patients will go on having knee

arthroplasty in the future?