What is the recommended management for iliopsoas tendonitis following total hip arthroplasty?

Management of Iliopsoas Tendonitis After Total Hip Arthroplasty

Begin with conservative management using NSAIDs or COX-2 inhibitors combined with ultrasound-guided corticosteroid injections, reserving surgical intervention (endoscopic iliopsoas tenotomy) for patients who fail conservative treatment after 3-6 months.

Initial Conservative Management (First-Line)

Start with a multimodal analgesic regimen that mirrors the evidence-based approach for post-THA pain management:

• NSAIDs or COX-2-selective inhibitors as the foundation of treatment 1
• Paracetamol can be added for additional analgesia 1
• Physical therapy focusing on hip flexibility and strengthening 2

Ultrasound-guided corticosteroid injections into the iliopsoas bursa represent the next step when oral medications alone are insufficient 3. The evidence shows:

• 78.6% overall success rate in resolving groin pain 3
• Mean Harris Hip Score improvement from 69 to 81 points 3
• Higher success rates (81.8% pain resolution) in patients without anterior cup overhang 3
• Lower success rates in patients with mechanical impingement from cup overhang 3

Critical Decision Point: Assess for Mechanical Impingement

Obtain cross-table lateral radiographs or CT scans to evaluate for anterior acetabular cup overhang 3. This distinction is crucial because:

• No cup overhang: Conservative management with injections is highly effective (82% success), with only 18% having persistent pain 3
• Cup overhang present: 25% (5/20) required acetabular revision despite injection, indicating mechanical etiology 3

Surgical Management (Second-Line)

When to Proceed to Surgery

Consider surgical intervention when:

• Persistent symptoms after 3-6 months of conservative management including at least one injection trial
• Confirmed diagnosis via positive response to diagnostic injection 4
• Failed conservative management with NSAIDs, physical therapy, and corticosteroid injections 2, 4

Surgical Options: Endoscopic Tenotomy (Preferred)

Endoscopic iliopsoas tendon release at the lesser trochanter is the preferred surgical approach over open tenotomy or acetabular revision 4, 5. The evidence strongly supports this:

Endoscopic tenotomy outcomes 4:

• 97.2% success rate (only 2.8% failure)
• Significant improvement in all patient-reported outcomes at every time point (p < 0.001)
• Biggest improvement within first 4 weeks post-surgery
• 71% patient satisfaction rate 6
• Minimal complications with no reported complications in recent series 4

Comparison to open tenotomy 5:

• Endoscopic: 91.8% successful outcomes (56/61 patients)
• Open: 77.8% successful outcomes (21/27 patients)
• Lower complication rate with endoscopic approach

Important Surgical Consideration

Endoscopic tenotomy can be performed even in the presence of cup malposition or edge loading 4. This is a critical finding because it means you can avoid acetabular revision surgery in most cases. The 2024 study showed excellent outcomes regardless of component position, with only 10% showing edge loading and 50% having variable cup overhang 4.

Acetabular Revision (Last Resort)

Reserve acetabular component revision for:

• Failed endoscopic tenotomy
• Severe mechanical impingement with cup overhang that failed both conservative and tenotomy approaches 3
• All 5 patients who underwent revision after failed injection in the cup overhang group had complete pain resolution 3

Clinical Predictors of Success

Better outcomes with conservative management (injections) when 3:

• No anterior cup overhang
• Earlier intervention
• Lower baseline pain scores

Better outcomes with endoscopic tenotomy when 6:

• Cup prominence >8 mm
• BMI >30
• Less than 2 years from index THA
• VAS pain scores <5

Common Pitfalls to Avoid

1. Don't rush to acetabular revision: Endoscopic tenotomy should be attempted first, even with cup malposition 4, 5
2. Don't dismiss injection therapy: 78.6% success rate makes it worthwhile before surgery 3
3. Don't use open tenotomy as first surgical option: Endoscopic approach has superior outcomes and lower complications 5
4. Don't forget diagnostic injection: A positive response confirms the diagnosis and predicts surgical success 4

Algorithmic Approach

1. Confirm diagnosis with physical examination (HEC test has 94% sensitivity, 88% specificity) 7 and imaging for cup position
2. Start NSAIDs/COX-2 inhibitors + physical therapy for 6-12 weeks
3. If persistent: Ultrasound-guided corticosteroid injection
4. Assess response at 3-6 months:
   • Success: Continue conservative management
   • Failure: Proceed to endoscopic iliopsoas tenotomy
5. If tenotomy fails (rare, 2.8%): Consider acetabular revision only then 4