Total Hip Replacement (THR) Protocol

1. Indications

• Osteoarthritis (primary and secondary) - the most frequent indication
• Rheumatoid/inflammatory arthritis
• Avascular necrosis (AVN) of the femoral head
• Displaced femoral neck fractures (in the elderly or physiologically frail)
• Post-traumatic arthritis
• Dysplastic hip disease
• Ankylosing spondylitis
• Failed previous hip procedures (e.g., hemiarthroplasty, internal fixation)

2. Components and Design Principles

• Biocompatible and inert
• Well fixed to host tissue
• Allow good range of movement and stability
• Minimize wear particles (to prevent osteolysis)
• Release non-toxic materials
• Remove the minimum amount of bone (to allow future revision)
• Cost-effective and ideally outlive the patient

Femoral Component Materials

Bearing Surfaces (Table 39.6 - Bailey and Love)

3. Fixation Method

• Requires: live host bone + appropriate ingrowth surface + initial rigid fixation
• Hydroxyapatite coating shortens time to biologic fixation
• Motion within bone leads to fibrous encapsulation instead of osseointegration
• Femoral stress shielding results from modulus mismatch between stem and femoral bone

4. Surgical Approaches

5. Perioperative Protocol

Preoperative

• Patient optimization (medical comorbidities, BMI, nutritional status)
• Blood management: patient blood management programs including erythropoietin and intraoperative blood salvage, especially for elective THR
• Antibiotic prophylaxis planning (e.g., cefazolin within 60 min of incision)
• Templating: restore correct offset, center of rotation, and leg length

Intraoperative

• Antibiotic prophylaxis: perioperative antibiotics are a key part of infection prevention, alongside strict aseptic technique in theatre - [Bailey and Love, 28th Ed](p. 581)
• Reproduce patient's anatomy: correct offset, center of rotation, component orientation, leg length restoration
• Intraoperative radiographs/fluoroscopy (especially with anterior approach) to verify implant position

Postoperative

• Hospital stay: typically 2-3 days; day-case THR is performed in select centers
• Physiotherapy: early mobilization to avoid dislocation-prone movements, especially for the first 6 weeks
• Occupational therapy: home assessment prior to discharge; raised toilet seat, grab rails, etc.
• Radiographs: mandatory post-op to confirm implant alignment/orientation and exclude iatrogenic fracture
• Follow-up: outpatient review at 6 weeks and 1 year post-surgery

6. VTE Prophylaxis

• Adequate hydration
• Regional anaesthesia (reduces VTE risk vs. general anaesthesia)
• Early mobilization
• Mechanical devices: TED stockings, foot pumps, intermittent pneumatic calf compression
• Chemical thromboprophylaxis (continued for 4-6 weeks post-op):
  • Low-molecular-weight heparin (LMWH)
  • Warfarin
  • Direct oral anticoagulants (DOACs - e.g., rivaroxaban, apixaban)

7. Complications

Intraoperative

• Nerve injury (sciatic, femoral, obturator nerves; most commonly deep peroneal nerve - foot drop)
• Vascular injury (femoral vein/artery)
• Femoral or acetabular fracture
• Cement fragments left in joint

Postoperative

Dislocation Management

• Closed reduction under conscious sedation (traction/manipulation) - usually successful
• Recurrent dislocation + malpositioned components → component revision
• Recurrent dislocation + well-positioned components → larger femoral head, dual-mobility construct, or constrained THA - [Schwartz's, 11th Ed](p. 519)

8. Revision THR Indications

• Symptomatic implant loosening (aseptic or septic)
• Recurrent dislocations
• Periprosthetic fracture
• Femoral prosthesis fracture
• Significant osteolysis/polyethylene wear

• Bailey and Love's Short Practice of Surgery, 28th Ed, Ch. 39 (pp. 580-582)
• Schwartz's Principles of Surgery, 11th Ed, Ch. 43 (pp. 1934-1938)
• Miller's Review of Orthopaedics, 9th Ed, Section 5-7 (pp. 11608-11660)
• Campbell's Operative Orthopaedics, 15th Ed 2026
• Rockwood and Green's Fractures in Adults, 10th Ed 2025

Physiotherapy After Total Hip Replacement (THR)

Phase 0 - Preoperative (Prehabilitation)

• Transfers (bed to chair, chair to standing)
• Correct use of walking aids (walker, crutches, cane)
• How to negotiate stairs safely
• Dislocation precautions - movements to avoid post-op
• Expected discharge process (ambulatory surgery centre or hospital)

Phase 1 - Immediate Postoperative (Day 0-1)

Positioning

• Hip positioned in approximately 15 degrees of abduction during anaesthetic recovery
• Posterior approach (PA): triangular abduction pillow between the thighs to maintain abduction and prevent extremes of flexion; pillows must be strapped carefully to avoid peroneal nerve pressure
• Direct anterior approach (DAA): a standard pillow may be used instead
• When sitting: one or two pillows in the seat of the chair to prevent excessive hip flexion; an additional pillow between the thighs limits adduction and internal rotation

Gait Training

• Gait training begins on the day of surgery in most patients
• Elderly patients: walker for balance and stability initially
• Younger patients: typically need a walker for only a few days, then progress more rapidly

Phase 2 - Early Mobilization (Days 1-6, Inpatient)

Weight-Bearing Protocol

• Method of fixation (cemented vs. cementless)
• Presence of structural bone grafts
• Stress risers in the femur
• Whether a trochanteric osteotomy was performed

Activities of Daily Living

• Bathroom privileges with an elevated toilet seat when the patient can walk far enough with supervision
• Bedside commode may be used initially
• Occupational therapy: a few sessions to teach safe dressing, putting on shoes, picking up objects from the floor, and other ADLs
• Many simple assistive appliances are available (long-handled shoehorn, sock aid, grabber)

Discharge Criteria

1. Get in and out of bed independently
2. Walk over level surfaces
3. Climb a few steps

Phase 3 - Early Home Rehabilitation (Weeks 1-6)

Dislocation Precautions (first 6 weeks)

• No hip flexion beyond 90°
• No adduction (crossing legs)
• No internal rotation

Practical Restrictions (First 6 Weeks)

• Use an elevated toilet seat
• Sleep with one or two pillows between the knees when lying on the non-operative side
• Showers allowed when wound healing is satisfactory - no baths
• Sexual activity can be resumed, avoiding extremes of range of motion

Walking Aid Progression

• Continue two-handed support (walker/frame) until first outpatient visit at 2 weeks
• At 2-week review: transition to a single cane when strength and balance allow
• Continue cane use until pain and limp have fully resolved
• Timing of this transition is best decided between the patient and their supervising physiotherapist

Driving

• Uncomplicated primary THR: patients usually resume driving at approximately 2-4 weeks
• Individualized based on return of strength, leg control, and reaction time

Phase 4 - Strengthening and Return to Function (Weeks 6-12+)

Exercise Programme

• Strengthening exercises - improve gait, balance, and endurance
• Stretching exercises - continued until the patient can reach the foot for dressing and nail care
  • Foot dressing technique: place the ankle of the operated limb on the opposite knee
• Note: gait analysis and force-plate data show that recovery of hip abductor muscle strength is prolonged, with persistent abductor weakness still measurable at 1 year post-op (Foucher et al.) - supporting the need for a prolonged exercise regimen beyond the initial weeks

Outpatient / Home Physiotherapy

• Outpatient or home health physical therapy is historically recommended after hospital discharge
• Internet-based, self-directed physical therapy has grown in popularity at some centres; however, approximately one-third of patients on self-directed programs were found to require referral back to outpatient PT due to slow recovery (Klement et al., n=941)
• Patients with multiple joint involvement, pre-existing weakness, or lack of social support may need an inpatient rehabilitation facility before returning to independent living

Phase 5 - Return to Work and Activity (Months 1-3)

Permitted Activities

• Safe: swimming, cycling, golf
• Caution/avoid: jogging, racquet sports, repetitive impact loading, extremes of hip positioning - these may increase the risk of arthroplasty failure

Cardiovascular Benefit

Follow-Up Schedule