You’re walking into a patient’s room on postoperative day one after a Total Hip Arthroplasty (THA) —and a few moments later, you’re helping them out of bed while remembering exactly which way they can and cannot bend. That moment is where your knowledge of THA transitions from textbook to treatment.
What is Total Hip Arthroplasty (THA/THR)?
Total Hip Arthroplasty (THA), also called total hip replacement (THR), is a surgical procedure that replaces a diseased or damaged hip joint with a prosthetic implant. The procedure resurfaces the acetabulum with a metal shell and liner, replaces the femoral head with a metal or ceramic ball, and inserts a femoral stem into the proximal femur. This is a definitive intervention for end-stage osteoarthritis, avascular necrosis, or displaced femoral neck fractures.
Why THA Matters in Physical Therapy Practice
THA is one of the most common elective orthopedic surgeries in the U.S., and PT is essential to restoring mobility, strength, and function. Your Plan of Care (POC) depends heavily on the surgical approach—posterolateral versus anterolateral/anterior—which dictates precautions. Recognizing these precautions prevents the most feared complication: hip dislocation. Your role also includes managing pain, edema, and gait deficits while educating the patient on safe movements for discharge.
What You’ll See in the Clinic
In acute care, you’ll see a patient who is typically weight-bearing as tolerated (WBAT) or toe-touch weight-bearing (TTWB), depending on the surgeon. Watch for abductor weakness (Trendelenburg sign), decreased hip extension, and a stiff gait pattern. Patients often report anterior thigh pain or incisional discomfort. You’ll also see standard precautions—like no hip flexion beyond 90°, no adduction past midline, and no internal rotation (if posterior approach).
“Day 1 post-op left THA (posterolateral approach). Patient transfers with moderate assist, using a front-wheeled walker. Gait shows limited stance time on left and trunk lean to the right. Educated on posterior hip precautions: no bending past 90°, no crossing legs, no twisting. Plan: progressive ambulation and home exercise program focusing on gluteal activation and hip precautions.”
Common Pitfall & Pro Tip
⚠️ Pitfall: Treating every THA the same. Anterior approach patients often have fewer restrictions, but they may still be at risk for lateral femoral cutaneous nerve irritation. Ignoring the surgeon’s specific protocol can lead to dislocation or delayed healing.
💡 Pro Tip: Use functional cues to teach the precautions. For a posterior approach, tell your patient to imagine a “no-cross line” at midline and to “turn your toes out” when sitting or standing. Better yet, practice sit-to-stand with a pillow between the knees to prevent adduction.
Memory Aid for Total Hip Arthroplasty
Think “Socket and Ball”: The hip is a ball (femoral head) in a socket (acetabulum). After THA, you need to keep the ball from popping out of the socket. Remember the “Three Nos” for a posterior approach: No flexion past 90°, No adduction, No internal rotation. Simple, safe, and easy to teach.
NPTE Connection
Watch for questions that test your ability to identify hip dislocation precautions based on surgical approach, differentiate weight-bearing status, or sequence the phases of rehabilitation (early protected motion → strengthening → functional training). These are classic exam items.
Related Physical Therapy Concepts
THA rehab connects naturally to Gait Training (use of walker or cane), Joint Protection (hip precautions), and Muscle Strengthening (gluteus medius and quadriceps). It also overlaps with Osteoarthritis Management and Geriatric Rehabilitation, especially when addressing fall risk and functional independence.
Quick Reference
✓ Weight-bearing: Usually WBAT (surgeon-dependent) for standard THA ✓ Precautions (posterior approach): No >90° flexion, no adduction, no IR ✓ Priority level: High – Dislocation risk, safety, and functional recovery ✓ PT Interventions/Considerations: • Early mobilization with assistive device (walker → cane) • Strengthen hip abductors, extensors, and quadriceps • Gait training with verbal and tactile cues for heel strike and stance stability • Educate on safe transfers, sleeping positions, and ADL adaptations • Monitor for signs of infection, DVT, or dislocation
Bottom line: Total hip arthroplasty is a transformative surgery, but your clinical eye and teaching skills are what get that patient walking out the door safely—and confidently.