What is the cause of persistent hip pain after physical therapy (PT) and corticosteroid injection have failed?

From the Guidelines

For persistent hip pain that has not responded to physical therapy and injections, I recommend obtaining advanced imaging, specifically an MRI of the hip, as it is highly sensitive and specific for detecting many abnormalities involving the surrounding soft tissues and bone marrow, including labral tears, osteoarthritis, avascular necrosis, or tendinopathy 1. This approach is supported by the American College of Radiology, which suggests that MRI is frequently performed after initial radiographs to detect osseous and soft tissue abnormalities, and it should, in general, be the first imaging technique used after radiographs 1. Before proceeding with an MRI, X-rays should be obtained first if not already done to assess for structural abnormalities and arthritis. While waiting for imaging results, pain management can include NSAIDs like naproxen 500mg twice daily or ibuprofen 600mg three times daily with food, along with activity modification to avoid aggravating movements, as suggested by the 2020 US Department of Veterans Affairs/US Department of Defense clinical practice guideline for the non-surgical management of hip and knee osteoarthritis 1. Heat or ice application for 15-20 minutes several times daily may provide temporary relief. Advanced imaging is justified at this point because failure of conservative measures (PT and injections) suggests either a more serious underlying condition or an incorrect initial diagnosis. The results will guide next steps, which might include referral to orthopedic surgery, rheumatology, or pain management depending on findings. It's also important to consider the classification, definition, and diagnostic criteria of hip-related pain in young and middle-aged active adults, as recommended by the International Hip-related Pain Research Network, Zurich 2018, which suggests that imaging can help categorize hip disease into conditions such as FAI syndrome, acetabular dysplasia and/or hip instability, and other conditions causing hip-related pain without specific bony morphology 1. Additionally, the American College of Rheumatology 2012 recommendations for the use of nonpharmacologic and pharmacologic therapies in osteoarthritis of the hand, hip, and knee suggest that modalities such as instruction in joint protection techniques, provision of assistive devices, and use of thermal modalities may be beneficial for patients with hip osteoarthritis 1. However, the most recent and highest quality study, the 2021 Mayo Clinic Proceedings, suggests that MRI is the preferred imaging modality for evaluating hip pain, especially when labral tears or other soft tissue abnormalities are suspected 1. Therefore, an MRI of the hip is the recommended next step in the evaluation and management of persistent hip pain that has not responded to physical therapy and injections. Some key points to consider include:

• MRI is highly sensitive and specific for detecting soft tissue and bone marrow abnormalities
• X-rays should be obtained first to assess for structural abnormalities and arthritis
• Pain management with NSAIDs and activity modification can be used while waiting for imaging results
• Advanced imaging is justified after failure of conservative measures
• Results will guide next steps, including potential referral to orthopedic surgery, rheumatology, or pain management.

From the Research

Increased Hip Pain Imaging after PT and Injection Failed

• The patient's hip pain persists after physical therapy (PT) and injection, indicating a need for further evaluation and diagnosis 2, 3, 4.
• Imaging tests such as radiography, ultrasonography, or magnetic resonance imaging (MRI) may be necessary to determine the cause of hip pain 2, 3, 4.
• The location of hip pain (anterior, lateral, or posterior) can help guide the diagnosis and treatment plan 2, 4.
• Intra-articular pathology such as labral tears, femoroacetabular impingement, or osteoarthritis may require advanced imaging and/or early referral to an orthopedic surgeon 2, 3, 4.
• Anesthetic injection during hip MR arthrography can help differentiate between intra- and extra-articular pathology, with a positive predictive value of 91% for intra-articular pathology 5.

Diagnostic Approach

• A thorough history and physical examination are essential in diagnosing hip pain 2, 3, 4.
• Radiography of the hip and pelvis should be the initial imaging test, followed by MRI or other advanced imaging modalities if necessary 2, 3, 4.
• Ultrasound-guided anesthetic injections can aid in the diagnosis of an intra-articular cause of pain 2.
• Clinical examination tests, although helpful, are not highly sensitive or specific for most diagnoses, and a rational approach to the hip examination can be used 4.

Treatment Options

• Physical therapy may be beneficial for patients with non-arthritic hip pain, with exercises to help alleviate hip pain and improve strength, movement, and balance 6.
• Intra-articular injections, such as corticosteroid injections, may be used to treat intra-articular pathology 5.
• Surgical intervention may be necessary for certain conditions, such as femoroacetabular impingement, labral tears, or gluteus medius tendon tears, which typically have good surgical outcomes 2.