26. | Manual of Rheumatology and Outpatient Orthopedic Disorders (LB Spiral Manuals)

Chapter 19 Hip Pain

Manual of Rheumatology and Outpatient Orthopedic Disorders

Chapter 19 Hip Pain

Thomas P. Sculco and Paul Lombardi

Etiology
History
Physical examination
Laboratory and radiographic studies
Differential diagnosis
Therapy

I. Etiology. The bone and soft- tissue structures around the hip joint, thigh, and low back should be considered in evaluating the patient's symptoms.

Hip joint
1. Proximal femur and acetabulum.
2. Articular surfaces.
3. Synovium.
Periarticular soft tissues
1. Bursae. Greater trochanteric, iliopsoas, ischial.
2. Tendons. Hip abductor, adductor, internal-external rotators, extensors, flexors, and hamstrings.
3. Acetabular labrum. Soft-tissue rim surrounding the acetabulum.
4. Herniae. Inguinal, femoral.
Referred pain
1. Lumbosacral. L-1 and L-2 dermatomes traverse the proximal thigh.
2. Visceral. Ovarian and prostate disorders.
3. Knee symptoms. Obturator nerve supplies sensory innervation to the hip and knee. Hip pathology can present as knee pain.

II. History. Patients with hip pain usually complain of limitation of hip motion and a painful limp. Careful history taking may reveal childhood hip disorders such as Legg-Calv -Perthes disease, slipped capital femoral epiphysis, developmental dysplasia of the hip, and septic arthritis. Concomitant disorders such as osteoarthritis , rheumatoid arthritis (RA), malignancy, or low back pain may provide insight into the etiology of the hip pain. A history of alcohol or steroid use is pertinent in patients suspected of having osteonecrosis. Response to prior therapies, including physical therapy, antiinflammatory medications, modification of activity, or use of assistive devices, helps one to assess the severity of the pain.

Duration and location of pain
1. Pain of short duration is usually posttraumatic or inflammatory.
2. Pain that is chronic and progressive may indicate mechanical joint incongruity related to an underlying arthritis. The pain of osteoarthritis is usually alleviated with rest. Constant hip pain is characteristic of an inflammatory or neoplastic process. The presence of morning stiffness and its duration are important aspects of RA.
3. Groin pain with radiation into the buttock indicates hip joint dysfunction. Pure buttock or back pain without a groin component is usually back in origin. When patients say their hip hurts, they mostly point to the buttock. Lateral hip pain with radiation to the lateral thigh may be related to greater trochanteric bursitis or abductor tendinitis. Discomfort over the anterior superior iliac spine extending down the anterior thigh is associated with meralgia paresthetica ( inflammation of the lateral femoral cutaneous nerve).
4. Buttock pain may be related to ischial tuberosity bursitis or spinal disorders such as spinal stenosis, ruptured intervertebral disk, and instability.
Relation of pain to activity
1. Pain from the hip joint and surrounding soft tissues is usually aggravated by weight bearing and relieved by rest.
2. Patients will usually describe a specific position of the limb that exacerbates or relieves their symptoms.
Decreased function. Patients complain of progressive decrease in maximum walking distance and exercise tolerance. Ability to perform activities of daily living is decreased. These decreases can be quantified with functional assessment scores such as WOMAC, the Harris Hip Score, and SF-36.

III. Physical examination

Gait. Observe the patient entering the examination room, and note the presence of a limp or expressions of pain.
1. Abductor lurch (Trendelenberg gait). The patient shifts the center of gravity over the affected limb during the stance phase of gait to unload weakened abductors and avoid pain production.
2. Coxalgic gait. The patient quickly unloads the painful leg while bearing weight. Decreased stance phase of gait and stride length on the affected side will be seen.
3. Stiff hip gait. Patient will walk by rotating the pelvis and swinging the legs in a circular fashion.
Patient standing
1. Measure unequal leg lengths by balancing the pelvis with calibrated blocks, if necessary. Note a fixed pelvic obliquity if present.
2. Evaluate the spine for scoliosis or kyphosis.
3. Trendelenburg's sign. While bearing weight with one leg on the affected side, the patient will drop the opposite side of the pelvis because the hip abductor, which normally elevates the pelvis, is weakened. This may take 30 to 45 seconds to become apparent.
Patient supine
1. Record active and passive range of motion, and compare with values of the opposite side.
  1. Note flexion, extension, abduction, adduction, and internal-external rotation in both flexion and extension. Internal rotation is usually most affected in osteoarthritis.
  2. Snapping hip (coxa sultans) can be elicited with range of motion (see section V ).
  3. Thomas test for hip flexion contracture. Flex the contralateral knee and hip; extend the affected hip while keeping the lower back flat on the examination table. Note the amount of affected hip flexion present against the horizontal.
  4. Patrick's test for sacroiliac joint symptoms. While the patient is supine, place the affected side in a figure 4 position with knee flexed and ankle on opposite knee. Apply pressure to the knee. Positive result if significant pain is present in the contralateral sacroiliac joint.
  5. Hip apprehension test for acetabular labrum pathology. Flex, adduct, and internally rotate the affected limb while looking for pain.
2. Palpate the anterior hip capsule by applying pressure just inferior to the inguinal ligament over the femoral triangle, and evaluate the degree of tenderness.
3. Palpate the groin in supine and standing positions , searching for femoral or inguinal herniae.
4. Measure thigh circumference bilaterally to assess muscle atrophy.
5. Measure leg lengths with a tape measure, recording from umbilicus to medial malleolus and from anterior superior iliac spine to medial malleolus. Note whether a fixed pelvic obliquity is present.
6. Perform a complete neurovascular examination.
7. Examine the knee and ankle. Patients with RA will often present with polyarticular involvement.
Patient lying on unaffected side
1. Palpate the greater trochanteric area for bursal tenderness.
2. Assess abductor muscle power.
3. Ober's test for iliotibial band tightness. With the patient in the lateral position, extend the affected hip and attempt adduction. If you are unable to do this, the test result is positive.
Patient lying prone
1. Palpate the lumbosacral area to evaluate the low back as a potential source of pain.
2. Evaluate hip extensor power.
3. Palpate the sciatic notch for tenderness.
4. Ely's test for hamstring tightness. With the patient prone, extend the knees until the buttocks are raised involuntarily. Positive result if this happens.

IV. Laboratory and radiographic studies

Radiographs should include an anteroposterior view of the pelvis, and anteroposterior and lateral views of the affected hip. Lumbosacral films should be obtained if spinal pathology is present. Current films should be compared with prior ones, if available, to look for progression of disease. In osteoarthritis, patients' symptoms may often not correlate with the degree of radiographic involvement of the affected hip.
1. Degenerative changes in the hip joint, with osteophytes, subchondral sclerosis, and cyst formation, is consistent with osteoarthritis.
2. Periarticular osteoporosis and global joint space narrowing is seen in RA. Osteophytes are not typically present.
3. In cases of bone involvement by a neoplastic process, tissue erosion of 50% can occur before being detected on radiographs.
4. Computed tomography (CT) may be used to visualize complex acetabular pathology, and to determine the degree of bone involvement in a neoplastic or fracture process.
5. Magnetic resonance imaging (MRI) is the most sensitive tool for diagnosing occult hip fractures and osteonecrosis.
Laboratory studies. Directed by physical examination and history.
1. A complete blood cell count with differential, measurements of erythrocyte sedimentation rate or C-reactive protein, and hip aspiration should be performed if infection is suspected.
2. Serum and urine immunoelectrophoreses should be performed to rule out multiple myeloma in patients with bone pain in the setting of anemia and an elevated ESR.

V. Differential diagnosis

Hip joint
1. Acetabulum and proximal femur
  1. Fractures may occur in the femoral neck or intertrochanteric region. Fractures may also occur to the acetabulum after trauma. Stress fractures of the femoral neck or acetabulum, particularly in runners and patients with osteoporosis, may be seen.
  2. Primary or metastatic tumors may infiltrate the femoral head and acetabulum, and pathologic fractures may occur. The most common tumors to metastasize to bone are breast , lung, prostate, kidney, and thyroid . The most common primary tumor of bone is multiple myeloma.
  3. Osteonecrosis of the femoral head with or without collapse may produce severe hip pain, especially in alcoholics, patients taking steroid preparations and steroid-treated patients with systemic lupus.
2. Articulating surfaces
  1. Osteoarthritis, RA, ankylosing spondylitis, or septic arthritis may cause hyaline cartilage destruction with resultant hip joint incongruity and pain.
  2. Incongruity of the femoral head and subsequent arthritis can be seen in osteonecrosis with segmental collapse, or in the adult manifestations of pediatric hip disorders such as Legg-Calv -Perthes disease, slipped capital femoral epiphysis, and developmental dysplasia of the hip.
3. Synovium
  1. Synovitis of the hip joint may result from RA, seronegative spondyloarthropathies such as ankylosing spondylitis, viral infections, and hemophilia.
  2. Tuberculosis may lead to a proliferative synovitis and severe joint destruction. Hip aspiration, acid-fast stain , and histologic assessment culture confirm the diagnosis. Pigmented villonodular synovitis may lead to cyst formation in the femoral neck or joint destruction. The radiographic changes seen in these two conditions are present on both sides of the joint.
  3. Synoviochondromatosis is a benign cartilage tumor of the synovium that usually presents with pain and a decreased range of motion.
  4. Pigmented villonodular synovitis is a synovial proliferation in the hip joint characterized histologically by hemosiderin-stained synovium and giant cells .
Periarticular soft tissues
1. Bursae
  1. Greater trochanteric bursitis is common and produces acute pain over the lateral thigh, which usually radiates distally. Swelling and pain with weight bearing are often present, and a limp may result. Pain is present when the patient is lying on the affected side and often awakens the patient from sleep.
  2. Iliopsoas bursitis is uncommon. It may communicate with the hip joint in 15% of patients.
2. Tendons and fascia
  1. Hamstring, adductor, abductor, and rotator tendons may become inflamed at their insertions into bone. Piriformis syndrome is diagnosed by pain in the sciatic notch with palpation and resisted external rotation.
  2. The fascia lata is quite taut as it passes over the greater trochanter and may produce a snapping sensation and pain, particularly on hip flexion and adduction. Other causes of a snapping hip (coxa sultans) include a tight iliopsoas tendon and hypertrophic fovea.
3. Herniae
  1. Inguinal herniae, if symptomatic, may produce severe groin pain and limitation of hip motion.
  2. Femoral herniae with prolapse may produce severe groin pain and limping. However, pain is intermittent until incarceration occurs.
4. Referred pain
  1. Lumbosacral. Osteoarthritis involving the lumbosacral apophyseal joints can produce buttock pain. Radicular pain from nerve root irritation may be manifested in the lateral thigh or groin. Disk herniations involving L1-2 and L2-3 may produce these symptoms. Pott's disease, tuberculous infection of the intervertebral disks and vertebral bodies, may spread to the hip joint via the psoas muscle insertions along the anterior portion of the lumbar spine.
  2. Visceral origin
    1. Renal colic can radiate to the groin. Ovarian or prostate disorders may mimic hip pathology.
    2. Vascular occlusive disease of the aorta can produce buttock pain; femoral vein phlebitis can present with thigh and groin pain.

VI. Therapy. (For therapy of specific disease entities, see the appropriate chapters.)

Rest
1. Joint rest may be accomplished by unloading the affected hip with various forms of external support.
  1. Cane. It should be held in the contralateral hand to assist weakened abductors and to unload the hip. Forearm crutches or axillary crutches can be used in more severe disease or bilateral involvement.
Compresses
1. If an acute inflammatory condition involves a tendon or bursa, ice compresses are useful.
2. For chronic pain, moist heat improves local blood supply and relaxes spastic musculature.
Medications
1. Antiinflammatory medications are useful for arthritic problems involving the hip joint. Nonsteroidal antiinflammatory drugs such as ibuprofen 600 mg to 800 mg three times daily can be helpful. These medications are contraindicated in patients taking anticoagulants or who have peptic ulcer or renal disease. Cox-2 specific antiinflammatory agents may offer relief to patients who are currently unable to take traditional NSAIDs.
2. Analgesics. Darvocet-N 100 (100 mg of propoxyphene napsylate and 650 mg of acetaminophen) may be used in conjunction with an antiinflammatory drug. The dosage is one to two tablets q4h as needed.
3. Soft-tissue injections. For bursitis or tendinitis, local injection with 40 mg of methylprednisolone acetate (Depo-Medrol) and 3 to 5 mL of 1% lidocaine is effective. If no improvement occurs after one injection, two more weekly injections may be given.
Exercises
1. Attempts should be made to maintain passive and active hip motion without aggravating the underlying pain.
2. Gentle isometric exercises for the quadriceps and hamstrings and antigravity exercises as tolerated for hip flexors, extensors, abductors, adductors, and rotators are recommended. See Chapter 56 for specific exercise prescriptions. Weight reduction is an important aspect of the treatment of hip disorders. The prognosis in many hip disorders is guarded if aggravating factors such as obesity are not addressed. Ideal patient weights are listed in Appendix C.

Books@Ovid
Copyright 2000 by Lippincott Williams & Wilkins
Stephen A. Paget, M.D., Allan Gibofsky, M.D., J.D. and John F. Beary, III, M.D.
Manual of Rheumatology and Outpatient Orthopedic Disorders

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