Hip Osteoarthritis | Diagnosis & Treatment for Physiotherapists

Introduction

According to Felson et al. (2005) A classical feature of osteoarthritis is histological changes in the quality and thickness of joint cartilage. A decrease in joint cartilage leads to hypertrophy of the subchondral bone and osteophyte formation at the edges of the joint surfaces. Another consequence is chronic inflammation of the synovial tissue. All of these changes lead to irregular joint surfaces, bony enlargement, possible thickening of the joint capsule, and eventually hydrops. The resulting decrease in joint space is visible on radiographic imagery, which is why we also speak of “radiological osteoarthritis”.

Pain is the most evident limiting factor in osteoarthritis. As previously mentioned, the pathophysiology describes a loss of cartilage but nociceptors are missing in joint cartilage.

We know that a decrease in joint cartilage occurs also in those without clinical symptoms (radiological osteoarthritis).

Nociceptors are present in tissues surrounding the hip joint such as the joint capsule, ligaments, or the synovium. These nociceptors get triggered by the inflammation that occurs.

Osteoarthritis can occur post-traumatically, as a process of aging, and in other inflammatory conditions affecting the quality of joint cartilage.

Epidemiology

Hip osteoarthritis is less common than knee osteoarthritis. For the peak incidence between the age of 78-79, Felson et al. (1998) report an incidence of 600/100.000 person-years for females and 420/100.000 for males with hip osteoarthritis.
The point prevalence of osteoarthritis in the Netherlands in 2007 was 24,5/1000 in males and 42,7/1000 in females. Around the world, the prevalence is reported at 0,85% (Cross et al. 2014)

Clinical Picture

For most patients, the most evident symptom is pain. Patients mostly experience pain when starting to move or after prolonged loading. The pain usually increases over the course of the day. They may also report hearing or feeling crepitations.

Patients typically report morning stiffness of up to 60 minutes. Range of motion is usually limited due to osteophyte formation. This can manifest in the difficulty or inability to tie shoes or put on socks for example.

Physical Examination

The diagnostic criteria (ACR) for hip OA are (Altman et al. 1991):

• Age >45
• Pain for more than 3 months
• Pain during loading, no increase when sitting, radiating pain into the groin/buttock/low back
• Reduced internal rotation, external rotation, extension, and flexion with bone-to-bone end feel
• Weakness of the hip abductors
• Difficulty getting going and/or stiffness when moving
• Tenderness upon palpation of the inguinal ligament

Furthermore, a cluster of tests has been described by Sutlive et al. (2008). Furthermore, the FABER test and Trendelenburg sign are referenced in the literature as measures to identify intra-articular pathology and hip abductor weakness though their validity is questionable.

Other orthopedic tests for hip osteoarthritis are:

• Passive Range of Motion of the hip joint
• Active Range of Motion of the hip joint

Treatment

There is widespread consensus that conservative management of hip osteoarthritis is indicated as a first step before a total hip replacement may be considered. Randomized controlled trials of high quality showed that structured exercise programs result in decreased pain and disability compared to a control group.

National guidelines advocate for clinicians to educate a patient on the course of the condition and to promote self-management, which includes an active lifestyle, encouraging general movement, and if necessary, consulting a dietician.

With regards to exercise selection, it is advised to work across the spectrum from mobilization or “motor learning”, to balance or postural control exercises and of course strength training exercises. These exercises should work the hip complex three-dimensionally with an emphasis on the hip abductors. So let’s look at a couple of examples:

Mobilization/motor learning:

• Pelvic tilts sitting
• Hip hinge sitting/standing with aid(stick)
• Internal rotations/external rotations in sitting/lying

Posture control/ balance:

• Tandem stance (normal/Airex mat) open and closed eyes
• Single leg (normal/Airex mat) open and closed eyes
• Star excursion balance
• Hurdles side to side

Strength Training:

• Bridges (short and long lever/single leg)
• Leg Press
• BoxSquat
• Squats (kettlebell)
• Hip abductors supine/standing/clamshell/resisted standing (with aid holding on to chair)
• Adductor strengthening with a ball in supine, side-lying
• Skate sliders
• Hip extension (Roman chair/on a table with ankle weight)

These exercises can be done by a patient at home with minimal equipment. Remember that these are just sample exercises and not a tailored exercise program. The dosage of the exercise program should be tailored to the individual and their load-taking capacity and adhering to a rehab program of a minimum of 12 weeks is required.

Would you like to learn more about osteoarthritis? Then check out the following resources:

• Adding hip adductor strengthening to a strengthening program for knee OA  (Research review)
• Podcast Episode 036: Hip Pathologies with Mehmet Gem
• Podcast Episode 014: Knee Osteoarthritis with Anthony Teoli

References

Altman, R., Alarcon, G., Appelrouth, D., Bloch, D., Borenstein, D., Brandt, K., … & Wolfe, F. (1991). The American College of Rheumatology criteria for the classification and reporting of osteoarthritis of the hip. Arthritis & Rheumatism: Official Journal of the American College of Rheumatology, 34(5), 505-514.

Beumer, L., Wong, J., Warden, S. J., Kemp, J. L., Foster, P., & Crossley, K. M. (2016). Effects of exercise and manual therapy on pain associated with hip osteoarthritis: a systematic review and meta-analysis. British journal of sports medicine, 50(8), 458-463.

Cross, M., Smith, E., Hoy, D., Nolte, S., Ackerman, I., Fransen, M., … & March, L. (2014). The global burden of hip and knee osteoarthritis: estimates from the global burden of disease 2010 study. Annals of the rheumatic diseases, 73(7), 1323-1330.

Felson, D. T. (2005). The sources of pain in knee osteoarthritis. Current opinion in rheumatology, 17(5), 624-628.

Felson, D. T., & Zhang, Y. (1998). An update on the epidemiology of knee and hip osteoarthritis with a view to prevention. Arthritis & Rheumatism: Official Journal of the American College of Rheumatology, 41(8), 1343-1355.

Sampath, K. K., Mani, R., Miyamori, T., & Tumilty, S. (2016). The effects of manual therapy or exercise therapy or both in people with hip osteoarthritis: a systematic review and meta-analysis. Clinical Rehabilitation, 30(12), 1141-1155.

Sutlive, T. G., Lopez, H. P., Schnitker, D. E., Yawn, S. E., Halle, R. J., Mansfield, L. T., … & Childs, J. D. (2008). Development of a clinical prediction rule for diagnosing hip osteoarthritis in individuals with unilateral hip pain. Journal of Orthopaedic & Sports Physical Therapy, 38(9), 542-550.

Steinhilber, B., Haupt, G., Miller, R., Janssen, P., & Krauss, I. (2017). Exercise therapy in patients with hip osteoarthritis: effect on hip muscle strength and safety aspects of exercise—results of a randomized controlled trial. Modern rheumatology, 27(3), 493-502.