Total Hip Arthroplasty (THA)

Total Hip Arthroplasty (THA)

Prepared by Dr. Kayahan KARAYTUG 

Key Points

• THA is primarily indicated for end-stage symptomatic hip degeneration refractory to non-operative management.
• Success depends on accurate component positioning, restoration of hip biomechanics (offset, leg length, center of rotation), and stable soft-tissue tension.
• Approach selection (posterior, direct anterior, anterolateral, direct lateral) should match surgeon expertise and patient-specific risk factors.
• Major complications include dislocation, periprosthetic fracture, aseptic loosening, wound issues, prosthetic joint infection (PJI), and venous thromboembolism (VTE).

Overview

Total hip arthroplasty (THA) is a highly successful and cost-effective procedure that reliably improves pain, function, and quality of life in patients with debilitating hip pathology. The most common indication is hip osteoarthritis, followed by osteonecrosis, congenital/developmental disorders, inflammatory arthropathies, and post-traumatic degeneration.

Anatomy and Biomechanics

The hip is a diarthrodial ball-and-socket joint. Stability and load transfer depend on acetabular and proximal femoral geometry, the labrum, capsule, and surrounding musculature. THA aims to restore the hip center of rotation, femoral offset, and leg length while maintaining stable soft-tissue tension and an impingement-resistant range of motion.

Indications

• Symptomatic end-stage hip osteoarthritis refractory to conservative management.
• Femoral head osteonecrosis with collapse or secondary arthritis.
• Developmental dysplasia of the hip (DDH) with degenerative change.
• Inflammatory arthritis with pain, deformity, or functional limitation.
• Post-traumatic degenerative changes and selected sequelae of hip fractures.

Contraindications

Absolute / strong contraindications:

• Active local or systemic infection (including bacteremia).
• Uncontrolled medical comorbidity that prohibits anesthesia or safe rehabilitation (case-dependent).

Relative considerations (optimize and individualize):

• Severe vascular insufficiency or poor soft-tissue envelope.
• Poorly controlled diabetes, malnutrition, active smoking, or other modifiable risk factors.
• Severe neuromuscular disorders affecting stability or safe ambulation (individualized).

Implant Design and Bearing Options

Typical components:

• Acetabular shell (cementless press-fit or cemented) + liner.
• Femoral stem (cementless or cemented) + femoral head.

Common bearing couples (selection depends on age, activity, bone quality, and wear priorities):

• Ceramic-on-highly cross-linked polyethylene (CoP/HXLPE).
• Metal-on-highly cross-linked polyethylene (MoP/HXLPE).
• Ceramic-on-ceramic (CoC) in selected patients (consider noise and fracture risk).

Surgical Approaches

Common approaches include posterior, direct anterior, anterolateral, and direct lateral. Each has trade-offs in exposure, soft-tissue handling, dislocation risk profile, and learning curve. Regardless of approach, meticulous technique and accurate component placement are key determinants of outcome.

Technical Principles

1. Preoperative planning: assess leg length discrepancy, offset, and templating for implant sizing.
2. Acetabular preparation: restore hip center of rotation and achieve stable cup fixation and appropriate orientation.
3. Femoral preparation: achieve stable stem fixation, restore offset/length, and maintain appropriate version.
4. Stability assessment: confirm impingement-free ROM and adequate soft-tissue tension before closure.

Complications

• Dislocation (risk influenced by component position, soft-tissue tension, approach, and patient factors).
• Periprosthetic fracture (intraoperative or postoperative).
• Aseptic loosening and wear-related osteolysis (long-term).
• Wound complications and hematoma.
• Prosthetic joint infection (PJI).
• Venous thromboembolism (DVT/PE).

Clinical Outcomes

THA is associated with high patient satisfaction and durable functional improvement. With appropriate patient selection, planning, and perioperative optimization, long-term implant survivorship is commonly reported.

Pearls and Pitfalls

Pearls:

• Template routinely and document planned offset/length targets.
• Prioritize component position and soft-tissue tension to reduce instability.
• Optimize modifiable risk factors preoperatively (infection risk, nutrition, glycemic control, smoking).

Pitfalls:

• Relying on intraoperative feel without verifying leg length/offset restoration.
• Underestimating patient-specific instability risks (spinopelvic issues, neuromuscular conditions, compliance).
• Inadequate infection prevention pathway (skin prep, antibiotics, OR discipline).

References

• Callaghan JJ, Rosenberg AG, Rubash HE (eds). The Adult Hip. 3rd ed. Wolters Kluwer.
• Berry DJ, Lieberman JR (eds). Surgery of the Hip. Elsevier.
• AAOS. Clinical Practice Guidelines / Appropriate Use Criteria related to hip osteoarthritis and arthroplasty (latest version).
• Springer BD, et al. Proceedings/consensus documents on prevention and management of periprosthetic joint infection (MSIS/ICM).
• Campbell’s Operative Orthopaedics. Elsevier (THA chapters).
• Malchau H, et al. Registry-based survivorship concepts in THA (national arthroplasty registry reports).
• Parvizi J, Gehrke T (eds). Periprosthetic Joint Infection: Practical Management Guide. Springer.