What are the indications, peri‑operative management, potential complications, and alternative surgical approaches for the direct anterior approach total hip arthroplasty in adults (approximately 50‑80 years) with end‑stage hip osteoarthritis or rheumatoid arthritis who have adequate bone stock and limited comorbidities?

Direct Anterior Approach for Total Hip Arthroplasty

Surgical Approach Selection

The direct anterior approach (DAA) is a valid and safe option for total hip arthroplasty with comparable long-term outcomes to posterior and lateral approaches, though it offers modest early postoperative advantages in pain control and functional recovery that diminish by 5-6 weeks. 1, 2, 3

The American Academy of Orthopaedic Surgeons states that surgical approach (anterior, lateral, or posterior) does not significantly affect long-term outcomes in hip arthroplasty, with current evidence failing to support the superiority of one approach over another. 1, 2, 3

Indications

The DAA is appropriate for adults with end-stage hip osteoarthritis or rheumatoid arthritis requiring total hip replacement when: 1, 4, 5

• Radiographic evidence of hip OA exists with refractory pain and disability despite conservative management 1
• Adequate bone stock is present for prosthetic fixation 5
• Patient is deemed an appropriate surgical candidate with limited comorbidities 1
• Surgeon has adequate experience with the technique to minimize learning curve complications 5, 6

Early Postoperative Advantages

The DAA demonstrates several modest early benefits that are clinically relevant in the first 5 weeks: 2, 3, 7

• Lower pain scores on postoperative day 1 (though the VAS difference is <10mm, which is of questionable clinical significance) 2, 3, 7
• Decreased length of hospital stay compared to posterior approach 7
• Earlier discontinuation of assistive devices (approximately 8 days sooner) 7
• Earlier return to driving (approximately 5 days sooner) and leaving home (3 days earlier) 7
• Reduced narcotic requirements on postoperative day 1 and overall 7
• Improved early mobilization with increased walking distance on postoperative days 1-2 7

These advantages persist up to 5 weeks postoperatively but equalize with other approaches by 6 weeks. 2, 7

Surgical Technique Considerations

The DAA utilizes an internervous and intermuscular plane between the tensor fascia lata (superior gluteal nerve) and sartorius (femoral nerve), theoretically minimizing muscle damage. 4, 5, 6

Specialized surgical instruments and fracture tables designed specifically for DAA have made the approach more accessible, though they are not mandatory. 5, 6

Complications and Learning Curve

Unique Risks

The DAA carries specific complications that require attention: 2, 3, 5, 6

• Five-fold higher risk of iatrogenic nerve damage when performed as a minimally invasive technique compared to conventional approaches 2, 3
• Increased risk of intraoperative femoral fractures during the learning curve 5
• Lateral femoral cutaneous nerve injury (transient paresthesias) 5, 8

Learning Curve

A steep learning curve exists for the DAA, with complication rates decreasing substantially with surgeon experience. 5, 6 The variance in published complication rates (ranging widely across studies) is largely attributable to surgeon and institutional experience with the procedure. 6

Surgeons should anticipate higher complication rates during their initial cases and consider proctoring or specialized training before implementation. 5, 6

Overall Complication Profile

When performed by experienced surgeons, the DAA demonstrates: 8, 6

• Dislocation rates <1% (lower than traditional approaches) 6
• Acceptable overall complication rate of approximately 16% in revision settings 8
• Component placement more frequently in the "safe zone" compared to other approaches 6

Perioperative Management

Timing of Surgery

Surgery should be performed within 24-48 hours of hospital admission when medically optimized, as this timing is associated with improved outcomes. 1

Antirheumatic Medication Management (for RA/SpA/SLE patients)

For patients with rheumatoid arthritis, spondyloarthritis, or SLE undergoing elective THA: 1

• Continue nonbiologic DMARDs throughout the perioperative period 1
• Withhold biologic medications as close to 1 dosing cycle as scheduling permits prior to surgery 1
• Restart biologic medications after evidence of wound healing, typically 14 days postoperatively 1
• Continue glucocorticoids with appropriate stress-dose coverage perioperatively 1

VTE Prophylaxis

Strong recommendation for VTE prophylaxis in all hip arthroplasty patients, particularly elderly patients. 1

Prosthetic Selection

Use cemented femoral stems in older adults undergoing hip arthroplasty, as this carries a strong recommendation based on reduced periprosthetic fracture risk despite slightly increased surgical time and blood loss. 1

Pain Management Protocol

Surgical approach has minor impact on postoperative pain compared to the analgesic regimen employed. 2, 3 The optimal multimodal regimen includes: 2, 3

• Paracetamol (acetaminophen) plus COX-2 inhibitors or NSAIDs
• Intravenous dexamethasone 8-10mg
• Fascia iliaca block or local infiltration analgesia

Alternative Surgical Approaches

Posterior Approach

• Most commonly used approach with extensive surgeon familiarity 1, 3
• Slightly higher early postoperative pain compared to DAA (clinically insignificant difference) 2, 3, 7
• Historical concerns about higher dislocation rates have not been supported by recent evidence 1
• Similar long-term outcomes to DAA 1, 2, 3

Direct Lateral Approach

• Associated with lower postoperative pain but higher surgical complication rates compared to anterior and posterior approaches 2, 3
• Risk of abductor muscle damage with potential Trendelenburg gait 3
• Similar long-term outcomes to other approaches 2, 3

Clinical Decision-Making Algorithm

Choose the DAA when:

1. Surgeon has adequate experience (past the learning curve)
2. Patient prioritizes faster early recovery and return to activities
3. Patient accepts the small increased risk of nerve injury
4. Appropriate equipment and institutional support are available

Choose posterior or lateral approaches when:

1. Surgeon has limited DAA experience
2. Complex revision surgery is anticipated (though DAA is feasible for revisions in experienced hands) 8
3. Patient anatomy or body habitus makes DAA technically challenging
4. Specialized equipment is unavailable

Critical Pitfalls to Avoid

• Do not assume DAA provides superior long-term outcomes - all approaches equalize by 6 weeks to 3 months 1, 2, 3
• Do not attempt DAA without adequate training - the learning curve is steep with increased complications during initial cases 5, 6
• Do not use "minimally invasive" incision length as the primary goal - this significantly increases nerve injury risk without meaningful benefit 2, 3
• Do not rely solely on surgical approach for pain control - the analgesic regimen is more important than approach selection 2, 3
• Do not use uncemented stems in elderly patients - cemented stems have strong evidence for reduced periprosthetic fracture risk 1

Interdisciplinary Care

All hip arthroplasty patients should be managed within an interdisciplinary care program to decrease complications and improve outcomes, regardless of surgical approach selected. 1