Conservative Management for Osteoarthritis: Unlock Full Potential

Introduction

Although the benefits of education and exercise therapy are known and supported in clinical practice guidelines, many people with osteoarthritis of the knee or hip progress to surgery before having tried the recommended conservative treatment options. Joint replacement surgery is only recommended after an inadequate change from first-line treatments including education, exercise, and weight management. Trials by Svege et al. (2015), and Skou et al. (2015), and (2018) have indicated that participating in guideline-recommended and properly dosed exercise programs may delay or avoid joint replacement surgery. Until now, studies have only assessed which patient factors and baseline characteristics are related to progression to joint replacement surgery. The current study under review is pioneering by evaluating how changes in patient-reported outcomes or functional outcomes after exercise therapy can influence the progression to joint replacement surgery. The current question is: can conservative management for osteoarthritis help avoid joint replacement surgery?

Methods

To study the ability of conservative management for osteoarthritis and the risk of joint replacement surgery this cohort study utilized data from the Good Life with osteoArthritis in Denmark (GLA:D) Registry. The obtained data were linked with other national health registries, such as the National Patient Registry which contains info about diagnoses, and the National Prescription Registry which includes information on prescribed medications.

As this study is a cohort study, no treatment was applied like in a randomized controlled trial. A cohort study aims to follow a subset of people over time. In this case, the authors used patient data from the GLA:D Registry. The GLA:D Registry is a widely implemented conservative management program for osteoarthritis. It is designed to be a minimal intervention that offers 2 educational sessions and 12 supervised or home exercise sessions specifically designed for knee or hip osteoarthritis and adapted to each individual. In Denmark, people can self-refer or be referred to this program by their general practitioner or specialist. The treating physiotherapists are trained to deliver this GLA:D protocol.

The inclusion criteria for people to participate in the GLA:D program is a clinical diagnosis of osteoarthritis. The clinical diagnosis is based on the following criteria:

Age 45 years or older
Movement-related joint pain
No morning stiffness or morning stiffness that lasts for less than 30 minutes

Upon inclusion in the GLA:D program that offers conservative management for osteoarthritis, the participants were examined and their clinical characteristics were collected. These included

Body mass index
Average pain intensity in the past month was collected using a visual analog scale
Joint-related quality of life was assessed using the Hip disability and Osteoarthritis Outcome Score (HOOS) and Knee injury and Osteoarthritis Outcome Score (KOOS). The scores range from 0 to 100 with higher scores representing better joint-related quality of life.
Self-efficacy was assessed using the Arthritis Self-Efficacy Scale (ASES) and ASES other symptoms were evaluated as well. Here the scores range from 0 representing “very uncertain” to 100 “very certain”.
The question “Are you afraid that your joints will be damaged from physical activity and exercise?” was asked to inquire about fear of movement.
As part of the functional examination participants completed the 30-second timed chair stand test and a 40-meter fast-paced walk test.

The participants included in the GLA:D study were followed over time. The primary outcome was the rate of primary hip or knee replacements within two years after the program. The rate of primary hip and knee replacements was visualized using a Kaplan-Meier survival curve.

Predictor variables included changes in pain intensity over the 3-month program, quality of life derived from the KOOS and HOOS questionnaires, self-efficacy from the ASES questionnaire, functional test results, and fear of movement from baseline to three months. The hip and knee pain intensity scales were reversed to allow for a more consistent interpretation of the outcomes. For the hip and knee pain intensity, a positive change indicated an improved outcome.

The results were interpreted using hazard ratios for each 10-unit change in a predictor variable on a 0-100 scale.

Results

A large dataset was included in the study. 2304 patients were included in the hip cohort and 7035 in the knee cohort. At baseline, they reported moderate pain and impairments in quality of life and moderate self-efficacy. The cohorts had similar baseline characteristics.

After the 12 sessions of conservative management for osteoarthritis and the 2 educational sessions, the subjects were followed for two years. Over the study period of two years 10% of the knee cohort and 30% of the hip cohort progressed to primary joint replacement. Those who progressed to joint replacement surgery had this surgery at a mean of approximately one year after ending the GLA:D exercise program.

Progression to hip replacement surgery characteristics

Those who progressed to hip replacement surgery were 2 years older, had higher pain and joint-related quality of life, and lower self-efficacy at baseline and after participating in the conservative management for osteoarthritis program. The study revealed they had smaller improvements in pain and hip-related quality of life compared to the patients who did not progress to hip replacement surgery. Further, their self-efficacy scores worsened while the self-efficacy of people who did not progress to surgery improved. The attendance to the supervised sessions was similar for those who progressed to hip joint replacement and those who did not progress to surgery.

Progression to knee replacement surgery

Of the participants who progressed to receive knee joint replacement surgery, similar characteristics were found. They also were on average 2 years older. Their baseline pain scores, self-efficacy, and quality of life were significantly worse than in those who did not progress to joint replacement and this difference was retained at the follow-up. Equally like in the hip cohort, the participants that progressed to knee joint replacement had smaller improvements in pain and knee-related quality of life and deterioration rather than improvement in their self-efficacy scores.

Factors associated with progression to hip replacement

The analyses were adjusted for confounding variables and only the improvements in joint-related quality of life and self-efficacy were associated with the hazard of hip replacement.

An improvement of 10 points on the HOOS quality of life questionnaire was associated with a 26% reduction in the risk of progressing to a hip replacement surgery 2 years after the conservative management for osteoarthritis program.
A 10-point improvement in ASES self-efficacy was associated with a 10% reduction in the hazard of hip replacement.

Factors associated with progression to knee replacement

An improvement in knee pain intensity of 10 points led to a 19% reduction over the first 200 days after ending the conservative management for osteoarthritis program and a 10% reduction for the remaining follow-up period.
Functional improvements in the 40-meter walk speed and the number of chair rises were associated with reductions in the hazard of knee replacement during the first 200 days after ending the conservative program.

Progression to hip replacement when attaining clinically relevant improvements

A clinically relevant improvement in HOOS quality of life of 15 points is related to a 36% reduced hazard of hip replacement surgery.
A clinically relevant reduction of the pain intensity was not statistically significantly related to the progression to a total hip replacement.
Clinically relevant improvements of 10 points in self-efficacy are related to a 10% reduced hazard of total hip replacement

Progression to knee replacement when attaining clinically relevant improvements

A clinically relevant improvement in pain intensity of 15 points is related to a reduced hazard of progression to a total knee replacement by 27% in the first 200 days and in a 14% reduction of progression to total knee replacement in the period beyond 200 days.
Clinically relevant improvements in the KOOS quality of life scale of 15 points are related to a 41% reduced hazard ratio of progression to total knee replacement in the first 200 days and a 30% reduction in the following period.
A clinically relevant improvement in self-efficacy of 10 points is related with a 11% reduction in the hazard of knee replacement
When a clinically relevant increase of 2.1 repetitions in the chair stand test is attained the risk of knee replacement is reduced by 10% in the first 200 days. Side note, at least 3 repetitions should be performed as obviously we can not do 2.1 repetitions.

Questions and thoughts

Often studies like these are rolled out in waitlisted patients. Then the problem arises that these people have often no or bad expectations about exercise therapy making them less motivated. They assume from the beginning that surgery will be the only solution to fix their complaints. On the contrary, this study had only 2 percent of both cohorts were waitlisted for hip or knee replacement surgery.

Further, another strong point of this study was the high attendance to the exercise sessions, with over 80% of people in the hip and knee cohorts going to at least 10 of the 12 exercise sessions.

The analysis revealed that respectively 10% and 30% of people progressed to knee and hip replacement surgery after the conservative management for osteoarthritis program, irrespective of the attendance to the exercise program.

When 10% and 30% progress to worsening outcomes, that means that also 90% and 70% of participants did not progress to joint replacement surgery and thus had good outcomes. Since the analysis revealed that the progression in patients was irrespective of the adherence to the exercise program, it seems likely that some people are benefiting from participating in exercise therapy (so-called responders) while others are not (non-responders). The characteristics presented in this study can help determine who might benefit from following your physiotherapy program and those you might want to refer for a surgical opinion straightaway. The data from this study can thus be used to help you stratify your care processes and tailor it to the individual presenting.

Talk nerdy to me

The current study delivers evidence to support the conservative management for osteoarthritis exercise program as was delivered through the GLA:D study. This study did not compare the effectiveness of a treatment since it was not a randomized trial. Instead, by following a cohort of people with the same characteristic (a clinical hip or knee osteoarthritis diagnosis) over time and evaluating their progression to receive joint replacement surgery 2 years after participating in an exercise program, the authors were able to study the natural progression of osteoarthritis and examine the characteristics of responders and non-responders.

The requirement of a clinical diagnosis rather than one confirmed by medical imaging can be regarded as a limitation of the study. However, the Osteoarthritis: care and management guidelines of the NICE criteria indicate that a clinical diagnosis can be established confidently and requires no routine medical imaging in case no red flags or atypical presentations emerge. They state that a “clinical diagnosis is sufficient to diagnose OA and additional imaging procedures would increase costs with no significant benefits.” Furthermore, both Skou et al. (2020) and Young et al. (2020) reported that the NICE criteria outperformed the EULAR and ACR criteria, adding that the NICE criteria to establish an osteoarthritis diagnosis are widely recommended and accepted.

Take home messages

A lot of people with knee or hip osteoarthritis undergo surgery before completing the recommended conservative therapy alternatives. Joint replacement surgery is only advised when first-line management has not been effective. Trials have revealed that participating in guideline-recommended and adequately dosed exercise programs may delay or prevent joint replacement surgery and this study confirms this. Using the protocol as was done in the current study, you might improve your patient to a level where he can delay or avoid having their hip or knee replaced (early).