Ortho Dx: Avascular necrosis of the hip - Clinical Advisor

Ortho Dx: Avascular necrosis of the hip

Slideshow

  • Left hip radiograph of a 27-year-old woman with a several-year history of lower back and left hip pain.

    Slide

    Left hip radiograph of a 27-year-old woman with a several-year history of lower back and left hip pain.

  • Another left hip radiograph of the patient.

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    Another left hip radiograph of the patient.

A 27-year-old woman presents with lower back and left hip pain that has been present for several years. The previous year, the patient consulted a spine specialist, who diagnosed a lumbar spine strain. The woman underwent several months of physical therapy and received trigger-point injections, without relief. Recently, she started seeing a different physical therapist, who thinks the pain is related to her hip and recommended hip radiographs. The patient contacted her primary care physician, who ordered left hip radiographs and instructed her to follow-up with an orthopedist. She denies any medical problems and does not drink alcohol or use tobacco. She does not take any prescription medications currently but admits, “I’ve taken more steroid dose packs than I can count” for her asthma and cat allergy.

This case has been brought to you in partnership with the Journal of Orthopedics for Physician Assistants.

Radiographs of the patient's left hip revealed flattening of the femoral head and advanced degenerative changes consistent with the diagnosis of avascular necrosis (AVN) of the femoral head. Hip AVN is a relatively common condition that is caused by a...

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Radiographs of the patient’s left hip revealed flattening of the femoral head and advanced degenerative changes consistent with the diagnosis of avascular necrosis (AVN) of the femoral head. Hip AVN is a relatively common condition that is caused by a disruption of the blood supply to the femoral head. The condition is so common in fact that 10% of all total hip replacements performed in the United States are for AVN.

Taking oral steroids has been linked to the disease and could potentially be the cause in this patient. AVN can occur bilaterally in up to 80% of patients, and therefore, bilateral hip radiographs should always be ordered if AVN diagnosis has been made or is suspected. If AVN is diagnosed by means of radiographs, no further imaging is necessary.1

Symptoms of hip and lumbar spine pathology often overlap, causing a delayed diagnosis. Knowing the key physical examination findings and symptoms that differentiate hip and lumbar spine disease facilitates timely diagnosis and treatment. When the hip is the source of pathology, symptoms commonly include groin, thigh, and buttock pain. Hip pain is usually made worse with hip flexion and internal rotation. Lumbar spine pathology usually causes back and buttock pain, and with lumbar nerve impingement, radiating pain that travels distally past the knee. Pain to palpation over the lumbar spine and positive straight leg raise are common symptoms associated with lumbar spine pathology.

This patient’s case is a good example of the value of obtaining a careful medical history and performing an appropriate physical examination to make an accurate initial diagnosis.2

Dagan Cloutier, MPAS, PA-C, practices in a multispecialty orthopedic group in the southern New Hampshire region and is editor-in-chief of the Journal of Orthopedics for Physician Assistants (JOPA).

References

  1. Hatch D. Hip Osteonecrosis. http://www.orthobullets.com/recon/5006/hip-osteonecrosis. Accessed March 7, 2017.
  2. Buckland AJ, Miyamoto R, Patel RD, Slover J, Razi AE. Differentiating hip pathology from lumbar spine pathology: key points of evaluation and management. J Am Acad Orthop Surg. 2017;25:e23-e34. 
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