Knee OA Evaluation of treatment with orthotics (wedged insole and knee brace) Preliminary data Kjell G Nilsson, MD, PhD, FRACS Jan Karlsson, CPO Department of Orthopaedics Umeå University hospital Umeå, Sweden

Implant Research Unit Osteoarthrosis (OA) u OA is a very common disease u More common than diabetes and heart diseases u Incidence increases with age u However, common even in younger patients approx 5 % between 35 och 54 years have OA

Age Hip OA Knee OA Finger OA Prevalence of OA (%)

Implant Research Unit OA u 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 2003:1:64 Roos, Roos, Lohmander et al, Scand J Med Sci Sports 1998:8:439 Roos, 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 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

Effect size, examples

Present Study 1.Initially, offer all patients a laterally or medially wedged insole Follow up minimum 6 weeks 2.For those who are unsatisfied with insole, offer a knee brace in addition to insole Follow 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 referrals received 120 KOOS forms correctly filled out 90 KOOS forms received after 6 weeks treatment with insole/keel Insole/keel treatment 56 patients satisfied with insole/keel treatment 34 patients NOT satisfied with insole/keel treatment Addition of brace 34 KOOS forms received after 6 weeks of 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 ( ) 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

PainSymptomsADLSportsQoL Pre Keel 0.05ns Insole/Keel (90 patients) Paired t test Mean values ± 95% CI

PainSymptomsADLSportsQoL Pre Keel Insole/Keel (90 patients) Effect Size:

PainSymptomsADLSportsQoL Pre Keel ns Insole/Keel (women) Paired t test Mean values ± 95% CI

PainSymptomsADLSportsQoL Pre Keel Insole/Keel (women) Effect Size:

PainSymptomsADLSportsQoL Pre Keel 0.01ns Insole/Keel (men) Paired t test Mean values ± 95% CI

PainSymptomsADLSportsQoL Pre Keel Insole/Keel (men) Effect Size:

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)

PainSymptomsADLSportsQoL Men Pre Men Keel Women Pre Women Keel Women vs men w and w/o insole/keel Women keel vs men keel Women pre vs men pre Un-paired t test

Effects of insole/keel and age

PainSymptomsADLSportsQoL Pre Keel ns Insole/Keel (age < 60 years) Paired t test Mean values ± 95% CI

PainSymptomsADLSportsQoL Pre Keel Insole/Keel (age < 60 years) Effect Size:

PainSymptomsADLSportsQoL Pre Keel 0.04ns0.04ns0.001 Insole/Keel (age > 60 years) Paired t test Mean values ± 95% CI

PainSymptomsADLSportsQoL Pre Keel Insole/Keel (age > 60 years) Effect Size:

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)

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?

PainSymptomsADLSportsQoL Satisfied vs dissatisfied after 6w with insole/keel 56 Satisfied with keel 34 Dissatisfied with keel Un-paired t test

Effects of insole/keel and brace

PainSymptomsADLSportsQoL Pre Keel + orthosis Keel + Brace (34 patients) Paired t test Mean values ± 95% CI

PainSymptomsADLSportsQoL Pre Keel + orthosis 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 brace and age

PainSymptomsADLSportsQoL Pre Keel + orthosis Keel + Brace (< 60 years) Paired t test Mean values ± 95% CI

PainSymptomsADLSportsQoL Pre Keel + orthosis Keel + Brace (< 60 years) Effect Size:

PainSymptomsADLSportsQoL ns Pre Keel + orthosis Keel + Brace (> 60 years) Paired t test Mean values ± 95% CI

PainSymptomsADLSportsQoL Pre Keel + orthosis Effect Size Keel + Brace (> 60 years) Effect Size:

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 (sports/recr) to 0.12 (symptoms) Keel+Brace old

Effect size, examples 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?