Inguinal / Hip Pain Algorithm

1) There are many types of referred hip pain, especially those resulting from lumbar radiculopathy. Referred pain rarely comes from the abdominal region.

2) In traumatic circumstances, an x-ray of the hip is a must and MRI is rarely useful. If symptoms persist, options are to request inlet or outlet views of the pelvis or a CT scan of the hip or to ask the on-call orthopaedist for advice.

3) Actual hip pain may be intra-articular or extra-articular. Most often hip pain is extra-articular.

4) With osteoarthritis, joint space narrowing, a cystic change in the femoral or acetabular head, hip joint narrowing and osteophytes (Pincer), an MRI scan to diagnose a labral tear is not indicated, as the patient’s symptoms are explained by osteoarthritis. No labrum surgery is possible, especially in patients over 60 years of age who already have these radiological signs of hip osteoarthritis. The first sign of osteoarthritis of the hip its diminution of the medial rotation of hip with the hip at 90 degrees of flexion.

5) With a symptomatic hip with CAM or Pincer or dysplastic hip deformity on the pelvis AP x-ray, it is recommended to refer the patient directly to orthopaedics with no other tests for care.

6) Legg-Calvé-Perthes disease of the hip is a result of partial avascular necrosis at a young age. It progresses towards hip osteoarthritis with age. These problems require orthopaedic follow-up. No investigation is required, except for an x-ray of the hip.

7) In non-traumatic circumstances, hip pain with or without red flag, the essential basic test is a simple x-ray of the pelvis or hip.

8) Orthopaedic consultations should be for patients with symptoms that have persisted for over six weeks. Appropriate conservative treatment should have been initiated. VSA: Visual scale analog.

9) Considering that indications for hip MRI are very rare, it is suggested to see the hip pain algorithm. If there are still questions after referring to the inguinal pain algorithm, it is more economical to discuss the usefulness of this examination with the on-call orthopaedist, who can see the patient or approve a request for an MRI scan.

10) Surgical treatment options are hip arthroscopy, hip prosthesis, and rarely hip drilling for AVN and hip osteotomy.

11) Because of its high cost, a request for an MRI scan of the hip with contrast to rule out a labral tear should be reserved for the orthopaedic specialty, sports medicine, and members of the pain management clinic team. This test is less relevant for patients over 60 years, as the incidence of hip osteoarthritis increases with age in this population.

12) Indications for hip MRI are:

a) Investigation of a bone or soft tissue primary malignant tumour around the hip. Assessment of a skip metastasis of the distal femur. A hip or pelvis bone metastasis should be investigated with a CT scan;
b) Investigation of avascular necrosis of the femoral head with no associated deformity of the femoral head. Investigation of the hip opposite AVN complicated or not by collapse that results from a systemic or idiopathic and not traumatic cause;
c) Ruling out a symptomatic labral tear in a patient aged 60 or under with normal x-rays of the hip;
d) Ruling out a tear of the tendon insertions of the hip abductors at the greater trochanter;
e) Ruling out a pseudo-tumour in a patient who had a metal on metal hip prosthesis.

13) Hip avascular necrosis does not automatically require an MRI scan. With an x-ray showing flattening, even minor, of the femoral head or hip osteoarthritis associated with necrosis, MRI is not useful nor indicated. If the problem is bilateral, an MRI scan of the hip is indicated to investigate the non-affected side in presence of non-traumatic avascular necrosis of the hip. With AVN of the hip, the patient should be non-weight bearing or using crutches and is referred to orthopaedics with or without crushing of the articular surface on standard x-rays. Hip pain, especially after 60 years of age with normal x-rays, is often related to early osteoarthritis associated or not with hip synovitis. Avascular necrosis of the hip is a lot less prevalent than hip osteoarthritis.