Osteoarthritis (OA) is a degenerative condition as a result of mechanical overload in a weight bearing joint. Current thought is that hip OA results from a number of distinct conditions, each associated with unique factors and possible treatments that share a common final pathway.
The most common symptom of hip OA is pain around the hip joint (generally located in the groin area). Most of the time, the pain develops slowly and worsens over time, or pain can have a sudden onset. Aging and genetic factors are important contributing causes of hip OA.
Hip OA mainly affects the articular cartilage, as well as causing changes to the subchondral bone, synovium, ligaments and capsule leading to loss of joint space. Hip OA is prevalent in 10% of people above 65, where 50% of these cases are symptomatic. The hip is the second most painful joint (after the knee) as a result of osteoarthritis.
In primary OA, the disease is of idiopathic origin (no known cause) and usually affects multiple joints in a relatively elderly population.
Secondary OA usually develops as a result of a disorder affecting the joint articular surface (e.g., trauma) or from abnormalities of joint.
Risk factors: Previous hip trauma (causing injury or fracture), Primary inflammatory arthritis, Joint morphology, Genetics, Congenital and developmental hip disease, Subchondral bone defects, Obesity, Occupation causing excessive strain on hips, Increase in age, Gender (female > male), Sport (higher impact sport at a younger age can cause increase in articular cartilage strength, where low impact sport do not change the composition of the cartilage), Menopause, Metabolic diseases, Sedentary lifestyle, Femoroacetabular impingement, Avascular necrosis, Ethnicity - 80-90% less prevalent in the Asian population when compared to the Caucasian population in the USA, Diet - low Vitamin D, C and K levels
Signs & symptoms:
• Progressively increasing
• Aggravating movement; when hip is loaded wrong or too long
• Cold weather
• Eased with continuous movement
• Commonly in groin/thigh, radiating to buttocks or knee
• Constant pain, night pain
• Morning stiffness with end-stage osteoarthritis, usually eased with
movement (<1 hour)
• "Locking" of hip movement
• Decreased range of motion - leading to joint contractures and muscle
• Crepitus with movement
• Gait abnormalities - short limb gait, antalgic gait, Trendelenburg gait,
stiff hip gait
Joint preserving surgery prior to onset of hip osteoarthritis/early in disease process
Modification of risk factors: Weight control, Switching from high-impact to low-impact activities, Minimization of pain aggravating activities
Additional treatments include pharmacological treatment, physical therapy, and surgical.
Physical therapy plays a major role in the management of patients with hip osteoarthritis. The goal is to improve strength, mobility and increase range of motion. Physical therapy also helps relieve pain and restores normal movement in the hip and legs and also addresses pain management and functional adaptions. Patient-specific exercise programs has shown to decrease pain and improve function in hip osteoarthritis.
Total Hip Replacement (THR) -90% of total hip replacements are done as a result of end-stage hip osteoarthritis. It is a successful orthopedic procedure in the treatment of hip osteoarthritis, when conservative management has failed and is highly effective at relieving symptoms.