What is the recommended treatment for a patient with cam deformity, specifically regarding hip injection with corticosteroids, such as triamcinolone?

Hip Injection for Cam Deformity

Direct Answer

Corticosteroid injection is not the appropriate treatment for cam deformity itself; surgical correction is the definitive treatment for symptomatic cam-type femoroacetabular impingement (FAI), while corticosteroid injections may be used as a temporizing measure for associated hip osteoarthritis symptoms only. 1

Understanding Cam Deformity vs. Hip Osteoarthritis

Cam deformity is a structural bony abnormality of the femoral head-neck junction that causes mechanical impingement and progressive cartilage damage, not an inflammatory condition amenable to steroid treatment. 1, 2

• Cam deformity represents a significant risk factor for developing hip pain (relative risk 4.3), particularly when the alpha angle exceeds 61.5° at the 1:30 clock position or when internal rotation is limited to ≤20°. 2
• Surgical correction of cam deformity not only improves clinical function but also decreases T1ρ MRI values and bone mineral density, indicating stabilization of cartilage degeneration and improved joint health. 1
• The degenerative process associated with cam-type FAI requires biomechanical correction through surgery, not anti-inflammatory treatment. 1

When Corticosteroid Injection May Be Considered

If the patient has developed secondary hip osteoarthritis from longstanding cam deformity and is not a surgical candidate or is awaiting surgery, intra-articular corticosteroid injection may provide short-term symptomatic relief. 3, 4

Injection Requirements for the Hip Joint

• Hip injections require ultrasound or fluoroscopic guidance due to joint depth and proximity to neurovascular structures—this is a strong recommendation distinguishing hip from knee injections. 5, 3
• Strict aseptic technique is mandatory to minimize infection risk. 6

Evidence for Efficacy in Hip OA

• Intra-articular corticosteroid injections (80 mg triamcinolone acetonide) provide significant pain relief in hip osteoarthritis, with the greatest reduction in pain at rest and improved range of motion at 3-week follow-up. 4
• The American College of Rheumatology strongly recommends intra-articular corticosteroid injections for hip OA, though effects are time-limited without long-term improvement at 2-year follow-up. 3, 5
• EULAR guidelines recommend intra-articular steroid injections (guided by ultrasound or x-ray) for patients with a flare unresponsive to analgesics and NSAIDs. 3

Critical Timing Considerations

Avoid corticosteroid injection for 3 months preceding any planned hip surgery (arthroscopy for cam resection or joint replacement) due to theoretical infection risk. 5, 7

Dosing and Administration

• For hip joints, doses of 5-15 mg for larger joints are typical, though the FDA label indicates doses up to 40 mg for larger areas have been used. 6
• Triamcinolone acetonide 40-80 mg has been studied specifically for hip OA with demonstrated efficacy. 4
• The injection should be made into the synovial space for full anti-inflammatory effect. 6

Major Pitfall: Soft Tissue Injection

Do not inject corticosteroids into periarticular soft tissues (such as the greater trochanteric bursa) when treating cam deformity, as this provides no benefit for the intra-articular pathology and carries risk of severe soft tissue atrophy. 8

• A case report documented severe contour deformity requiring serial fat grafting after triamcinolone acetonide injection to the greater trochanteric bursa. 8
• Proper injection technique into the joint space (not surrounding tissues) is essential to avoid tissue atrophy. 6, 8

Definitive Treatment Algorithm

1. Confirm cam deformity diagnosis with imaging (alpha angle, internal rotation assessment). 2
2. If symptomatic with mechanical symptoms (catching, locking, activity-related pain): Refer for surgical evaluation for arthroscopic or open cam resection. 1, 9
3. If secondary hip OA with inflammatory symptoms (rest pain, effusion) and patient is not a surgical candidate: Consider image-guided intra-articular corticosteroid injection for short-term relief (3 months maximum benefit). 4, 5
4. If surgery is planned: Avoid corticosteroid injection within 3 months of the procedure. 5

Important Caveats

• Corticosteroid injections may contribute to cartilage loss, though the clinical significance remains uncertain as cartilage changes have not been associated with worsening pain or function in studies. 3, 7
• Repeat injections carry potential negative effects on bone health and joint structure that must be weighed against benefits. 5, 7
• The underlying cam deformity will continue to cause progressive damage regardless of symptomatic treatment with injections. 1, 2