It's also important to measure balance performance and activities that predict the risk of falls in adults with hip osteoarthritis.
What is hip osteoarthritis (OA)?
Hip osteoarthritis (OA) is a common disease with symptoms including joint pain, joint stiffness, and joint swelling. OA can result in functional impairment in daily activities, like walking, stair climbing, squatting, and bending. Due to its high prevalence in the older population, hip OA has a major impact on healthcare costs globally.
Recommended course: Osteoarthritis of the Hip: Rehabilitation and Treatment Strategies, 2nd Edition
Risk factors for hip osteoarthritis
The risk of developing hip OA increases with age. It is more likely to develop in people with a past hip injury or history of hip dysplasia. Obesity also may increase the risk of developing hip OA. Lifetime risk for symptomatic hip OA is 18.5% for men and 28.6% for women.
Evaluating patients with hip osteoarthritis
Evaluation of patients with hip OA should start with standardized outcomes measures. I like to use the Lower Extremity Functional Scale (LEFS), but the Hip disability and Osteoarthritis Outcome Score (HOOS) is also a well-used outcome measure. It is important to have a baseline to monitor the progress made as we grow through their treatment.
The next step is to assess activity limitation. This allows the therapists to monitor changes in the patient's level of function over the episode of care. Clinicians should utilize reliable and valid physical performance measures. For patients with hip OA, I like to use the 6-minute walk test, or the 30-second chair stand.
It's also important to measure balance performance and activities that predict the risk of falls in adults with hip osteoarthritis, especially those with decreased physical function or a high risk of falls. The 4-square step test helps measure both activity limitations and fall risk.
Performing a physical examination
Next in my evaluation is the actual physical examination, where I assess hip ROM and hip strength. Often you will find that hip internal rotation (IR) and hip extension are limited in ROM. Weakness of the hip abductors, hip flexors, and hip rotators is also common. Mechanically, the hip is very intertwined with the lumbar spine and the knee, so therapists need to assess lumbar mobility and knee strength as well.
Many patients with restricted hip extension also tend to have restricted lumbar extension, which therapists can use to improve hip mobility. Lastly, it's important to assess lower extremity flexibility, as the hip flexors, hamstrings and piriformis tend to be restricted for patients with hip related pathology.
Increasing hip ROM
If the patient has restricted hip ROM, I like to try to some hip distraction during my evaluation to see if we can make a quick change in their ROM. I prefer lateral distraction over long-axis distraction, but either one works.
Nothing is more powerful than showing the patient that some manual therapy can quickly change their ROM. It allows me to start the narrative that “exercise can really help improve your function and decrease your pain.” It also allows me to make a better prognosis. Patients that respond to manual therapy tend to improve faster than those who do not respond with manual therapy.
Conservative treatment approaches for hip osteoarthritis
Experts consider aerobic and strength training as the best conservative treatment approach in adults with mild-to-moderate knee OA. Despite current national and international guidelines for the use of exercise in patients with hip OA, however, there have been very few clinical exercise trials to research what the best conservative treatment is for patients with hip OA.
Programs developed for OA of the lower limbs — usually consisting of aerobic conditioning and improving quadriceps strength — seem to benefit patients with knee OA more than those with hip OA. Therapists will need specific exercise programs that benefit patients with hip OA.
Case study: Exercise programs for patients with OA
Uusi-Rasi, et al did a pilot study on a specific exercise program to help patients with OA. This 12-week study showed great promise: Pain declined 30% from baseline. Objective assessment of physical functioning showed statistically significant improvement in the maximal isometric leg extensor strength by 20%. Hip extension range of motion (ROM) showed a 30% improvement as well.
Experienced exercise leaders (physiotherapists) led training sessions 3 times a week for 12 weeks. Training was progressive and was implemented as group-based sessions but was planned with individual goals and limitations in mind.
The first two weeks focused on getting participants familiar with exercising. The next five weeks were dedicated to range of motion, lower limb muscle strength, balance, agility, mobility, and change of direction. Patients made progress using different surfaces, multidirectional movement patterns, and changing the support base. In addition to each patient’s own body weight, ankle or vest weights and step-boards of increasing height were used to increase the intensity of training. Advanced programs were also aerobic in nature.
During the last five weeks of the trial, trial participants used weight machines for strengthening the leg muscles, including knee extensors, hip extensors, hip abductors, hip rotators, knee extensors, calf muscles. The program also included exercises for the abdominal, back, shoulder, and arm muscles.
The program began with 30-60% of one repetition maximum (1RM) progressing to 60-75% of 1RM over 5 weeks. Participants completed two sets of each exercise, with each set consisting of 8-12 repetitions. The rate of perceived exertion scale (RPE) assessed the intensity of training.
Incorporating manual therapy and IASTM
My treatment approach for patients with hip OA is specific to each patient, but in general, I use Manual Therapy if the patient has pain and/or restricted ROM. I use Thrust and Non-Thrust joint mobilization with Instrument Assisted Soft Tissue Mobilization (IASTM) for the soft tissues around the hip.
The importance of patient education
The emphasis of the treatment for hip OA is on patient education and teaching them a home program that incorporates ROM, flexibility, balance, strengthening, and condition exercises. If the patient has access to a gym, I also teach them how to properly use the weight equipment and follow the pilot study described above.
One of the hardest parts of the treatment involves explaining to patients the importance of weight loss in assisting with regular physical activity. In many cases, I find it difficult to confront an obese patient with their obesity. However, it can be very rewarding to see the patient making lifestyle changes that help them both in the short and long term.
As Physical Therapists, we should not shy away from these discussions. As much as any therapy regimen, it’s vital that we educate our patients on the benefits of a proper diet, regular physical activity, good sleeping habits, and anything they can do to reduce stress and anxiety to help reduce their pain and improve their function.