Hip Joint Osteoarthritis

• Hip Joint Osteoarthritis is an inflammatory process occurs in the synovial joints such as the hip joint, and causes progressive loss of articular cartilage.
• The primary changes in hip joint osteoarthritis are:
  • Loss of articular cartilage
  • Remodeling of subchondral bone
  • Formation of osteophytes

Risk factors for Hip Joint Osteoarthritis

1. Obesity.
2. Joint trauma.
3. Muscle weakness;
   • These three factors all increase the mechanical forces to which the articular cartilage is subjected.
4. Gender: Female > male
5. Hormones.
6. Metabolic disorders.
7. Genetics.
8. Developmental or acquired deformities:
   1. Hip dysplasia.
   2. Slipped capital femoral epiphysis SCFE
   3. Legg-Calvé-Perthes disease.

• Elderly populations are affected by osteoarthritis more frequently and more severely than younger populations.
• Obesity is the strongest modifiable risk factor.

See Also: Risk factors associated with osteoarthritis disease

Pathophysiology

Clinical Evaluation

Symptoms & Signs:

• Hip pain that increased by activity.
  • By disease development, the pain occurs at rest and night, and limits the patient function.
• Stiffness of the hip joint.
• Sensation of instability, locking or catching.

See Also: Anatomic sources of pain in osteoarthritis

Physical Examination:

• Gait:
  • Analgesic gait
  • Trendelenburg gait.
  • Leg length discrepancy.
• Passive range of motion of the hip joint may causes pain.
  • Loss of internal rotation of the hip.
  • Limited hip flexion and extension
• Hip flexion contracture or limb length discrepancy may be present.
• Atrophy in muscles crossing the affected joint is often present in chronic disease.

See Also: Hip Examination Special Tests.

Imaging Evaluation

Radiographic:

• Recommended views:
  • Weight-bearing antero-posterior radiographs are the most effective at confirming the diagnosis of Hip Joint Osteoarthritis.
  • Antero-posterior view + Lateral view of the hip.
• Findings:
  1. Narrowing of the cartilage space
  2. Increased density of the subchondral bone (sclerosis).
  3. Osteophytes
  4. In more severe cases, subchondral cysts (geodes), loose bodies, joint subluxation, deformity, and malalignment may be present.
  5. Bony ankylosis is rare but may occur.

See Also: Osteonecrosis of the Hip

Treatment

Non-Operative Treatment:

• First line of treatment for all patients with hip joint osteoarthritis.
• Non-operative treatment includes:
  1. Activity modification.
  2. Reduce impact-loading exercises.
  3. Reduce weight.
  4. Avoid stairs, inclines, squatting.
  5. Drugs:
     1. Acetaminophen.
     2. Nonsteroidal anti inflammatory drugs (NSAIDs).
     3. Cyclooxygenase (COX)-2 inhibitors.
     4. Glucosamine and chondroitin sulfate.
     5. Prednisone.
  6. Physical therapy.
  7. Joint injections:
     1. Corticosteroid: anti inflammatory treatment.
        • Can be therapeutic and/or diagnostic of symptomatic hip joint osteoarthritis.
     2. Hyaluronate.
  8. Acupuncture
  9. Assist device (cane or crutch):
     • In the opposite hand of affected hip.
     • Decreases the joint reaction force on the affected hip.

Operative Treatment:

1. Arthroscopy of the hip joint:

• Indications:
  1. Traumatic labral tear not associated with dysplasia:
     • Labral resection should be avoided because it provides stability in a shallow acetabular socket (labrum usually is hypertrophic).
     • In cases of significant dysplasia, arthroscopic débridement is not recommended.
  2. Hip joint shows mechanical signs of locking, catching, and clicking.
  3. Loose body removal.
  4. Débridement of chondral flap tears.
  5. Synovitis: diagnostic biopsy and therapeutic lavage.
  6. Diagnostic procedure in undiagnosed mechanical hip pain cases.
  7. Degenerative arthritis:
     • Not helpful in moderate to advanced disease
     • Generally, will help only mechanical symptoms, not arthritic ache.

2. Osteotomy:

• Indicated in adult / young patients with symptomatic dysplasia with concentrically reduced hip and mild-to-moderate arthritis.

3. Total Hip Arthroplasty:

• Indicated in:
  • End-stage and symptomatic or severe hip joint osteoarthritis.
  • It’s a preferred treatment for older patients (>50) and those with advanced structural changes.

4. Hip fusion:

• Less frequently used as THA technology advances
• Classical indication:
  • Very young male laborer
  • Unilateral hip arthritis
• Fusion position:
  • 20 to 25 degrees of flexion.
  • Neutral abduction.
    • Increased back and knee pain when fusion is done in abduction position.
  • Neutral or slight external rotation of 10 degrees.
• Indications to convert hip fusion into THA:
  • Disabling back pain—most common.
  • Disabling ipsilateral knee pain with instability.
  • Disabling contralateral hip pain.

5. Femoral Head Resection:

• Indicated in:
  • Pathological hip lesions.
  • Painful head subluxation.