Exercise in Patients With Osteoarthritis of the Hip

According to Danish and international guidelines the recommended first-line of management for people with osteoarthritis consist of exercise, education, analgesic medication, and, if necessary, weight reduction. It is well documented that exercise has a positive effect on pain and physical function in patients with knee OA, but the effect of exercise on hip OA is sparsely investigated. Aim of the study: To investigate the effects of 1) strength training, and 2) Nordic Walking, and 3) unsupervised home based exercise on muscle function, endurance, pain level, physical activity, and health related quality of life in patients with osteoarthritis of the hip. The effects of exercise on muscle mass and the mechanisms behind the osteoarthritis, i.e., disease activity, inflammation, and cartilage degradation, are investigated in a subgroup (n=45) of the participants. Study hypotheses: Strength training will have a greater effect on physical function and muscle strength than Nordic Walking and home based exercise; 2) Nordic Walking will have a greater effect on endurance than strength training and unsupervised home based exercise; 3) Strength training and Nordic Walking will have a greater effect on pain level and health related quality of life than unsupervised home based exercise.

Strength training three times weekly, i.e.supervised strength training twice weekly and un-supervised strength training once weekly for 4 months.

Nordic walking three times weekly, i.e.Nordic walking twice weekly and un-supervised Nordic walking once weekly for 4 months.

The home based unsupervised exercise comprised exercises recommended by the Danish Arthritis Association.

Supervised strength training in groups 2 x 1 hour weekly and un-supervised strength training 1 hour weekly for 4 months

Supervised Nordic Walking in groups 2 x 1 hour weekly and un-supervised Nordic Walking 1 hour weekly for 4 months

Unsupervised home based exercise as recommended by the Danish Arthritis Association 1 hour 3 x weekly for 4 months

Change from Baseline to 2, 4 and 12 months in isometric muscle strength (N) of the thigh and hip muscles at 2, 4 and 12 months

Change from Baseline to 2, 4 and 12 months in lower limb extensor muscle power (Watt/kg BW) at 2, 4 and 12 months

Change from Baseline to 2, 4 and 12 months in 6 minute walking distance (m), stair climbing time (s), 15 s marching on the spot (number of knee lifts), Timed-Up-and-Go (s) at 2, 4 and 12 months

Change from Baseline to 4 months in the anatomical cross sectional area (cm2) of the quadriceps femoris muscle measured with MRI. The measurements are performed in a subgroup (15 participants from each group)

MRI (magnetic resonance imaging)- The anatomical cross sectional area is measured at mid-thigh level, i.e. 20 cm proximal to the tibia plateau.

Change from Baseline to 4 months in biomarkers of disease activity, inflammation, and cartilage degradation, in a subgroup (15 participants from each group)

Blood samples: COMP (cartilage oligomeric matrix protein) and CRP (C-reactive protein)and Urine sample: CTX II (C-terminal telopeptide of collagen II)

Inclusion Criteria: 1)Home-dwelling 60+ year old persons with primary, symptomatic hip OA who meet the clinical criteria of hip OA according to American College of Rheumatology (ACR), and who are not on a waiting list for hip joint replacement. Exclusion Criteria: symptomatic OA in the knee or the big toe, joint replacement of the knee or the hip, other types of arthritis, e.g., rheumatoid arthritis, previous hip fracture, limitation in physical function to the extent that using public transportation is impossible, co-morbidity that prevents exercising, physiotherapy related to hip problems within the last 3 months, steroid injections in the hip joint within the last 3 months, performing exercise/sports 2+ times weekly, and inability to cooperate.

Institute of Sports Medicine - Copenhagen & Musculoskeletal Rehabilitation Research Unit, Bispebjerg Hospital

Institute of Sports Medicine - Copenhagen & Musculoskeletal Rehabilitation Research Unit, Bispebjerg Hospital