What are the step-by-step procedures for a total hip replacement using the posterior approach?

Step-by-Step Procedure for Total Hip Replacement Using the Posterior Approach

Pre-operative Preparation

The posterior approach to total hip arthroplasty requires meticulous attention to patient positioning, soft tissue handling, and enhanced capsular repair to minimize dislocation risk while providing excellent surgical exposure.

Patient Positioning and Anesthesia

• Position the patient in lateral decubitus position with the operative hip facing upward 1
• Either spinal or general anesthesia is appropriate, with both showing equivalent safety profiles 1
• Ensure adequate hydration before induction and maintain systolic blood pressure within 20% of pre-induction values throughout surgery using vasopressors and/or fluids 1
• Consider invasive blood pressure monitoring for higher-risk patients (elderly, male sex, significant cardiopulmonary disease, or diuretic use) 1

Analgesia Strategy

• Administer intra-operative strong long-acting opioids to secure analgesia when the patient awakens 1
• Consider peripheral nerve blockade (femoral nerve block or posterior lumbar plexus block) which can be continued postoperatively 1
• Alternatively, use spinal local anesthetic with morphine 0.1-0.2 mg for lasting postoperative analgesia 1
• Administer pre-operative dexamethasone 8-10 mg to reduce pain scores, opioid consumption, and length of stay 1

Surgical Technique

Incision and Exposure

• Make a posterior incision centered over the greater trochanter 2
• Incise the fascia lata in line with the skin incision 2
• Split the gluteus maximus muscle fibers bluntly in line with their orientation 2
• Identify and protect the sciatic nerve throughout the procedure 2

Deep Dissection

• Perform external rotation of the hip to expose the short external rotators 2
• Tag the piriformis tendon and short external rotators with sutures for later repair 3
• Incise the posterior capsule in line with the femoral neck, preserving tissue for enhanced repair 3
• Dislocate the hip posteriorly by flexion, adduction, and internal rotation 2

Femoral Head Removal and Acetabular Preparation

• Once the femoral head is removed, maintain heightened vigilance for cardiovascular events as this is when bone cement implantation syndrome risk increases 1
• Confirm with anesthesia team before instrumenting the femoral canal 1
• Expose the acetabulum by placing retractors around the rim 2
• Ream the acetabulum to bleeding bone, using patient-specific anatomic landmarks (anterior acetabular rim and transverse acetabular ligament when visible) rather than relying solely on traditional radiographic abduction and anteversion goals 4
• Position the acetabular component with mean abduction of approximately 48° and anteversion of approximately 25° based on anatomic landmarks 4

Femoral Preparation (If Using Cemented Fixation)

• Carefully prepare, wash, and dry the femoral canal using a pressurized lavage system to clean endosteal bone of fat and marrow contents 1
• Place a distal suction catheter on top of an intramedullary plug 1
• Insert cement from a gun in retrograde fashion on top of the plug, pulling the catheter out as soon as it is blocked with cement 1
• Avoid excessive manual pressurization in patients at higher cardiovascular risk 1
• Have vasopressors (metaraminol/adrenaline) immediately available for potential cardiovascular collapse during cementation 1

Note: Current guidelines strongly support the use of cemented stems in hip fracture patients for improved pain-free mobility, reduced reoperation rates, and lower 30-day mortality compared to uncemented prostheses 1

Component Implantation

• Insert the acetabular component with secure press-fit fixation 2
• Consider using a monoblock dual-mobility construct to minimize dislocation risk 4
• Insert the femoral component (cemented or uncemented based on indication) 1
• Reduce the hip and perform a significant, dynamic intra-operative test of range of motion to assess stability 4

Enhanced Posterior Soft Tissue Repair

The enhanced posterior soft tissue repair is critical and reduces dislocation rates from 4-6% to less than 1% 3

• Meticulously repair the posterior capsule using strong, non-absorbable sutures 3
• Reattach the short external rotators (piriformis, obturator internus, gemelli) to their anatomic insertion on the greater trochanter 3
• Ensure robust repair of all posterior structures to restore the posterior restraint mechanism 3

Closure

• Close the gluteus maximus fascia 2
• Close the fascia lata and subcutaneous tissues in layers 2
• Close the skin with sutures or staples 2

Post-operative Management

Immediate Post-operative Care

• For high-intensity pain (VAS >50): Use COX-2 selective inhibitors or conventional NSAIDs plus IV strong opioids by PCA or regular injection 1
• For moderate to low-intensity pain (VAS <50): Use COX-2 selective inhibitors or conventional NSAIDs plus paracetamol, with weak opioids as needed 1
• Paracetamol should be given as baseline treatment for all pain intensities in combination with other analgesics 1

Mobilization and Precautions

• With enhanced posterior soft tissue repair and modern dual-mobility constructs, traditional posterior hip precautions may not be necessary 4
• Allow weight bearing as tolerated immediately after surgery 1
• Initiate VTE prophylaxis for 1 month duration 1

Common Pitfalls to Avoid

• Inadequate posterior soft tissue repair is the primary cause of posterior dislocations; meticulous repair technique is non-negotiable 3
• Failure to communicate with anesthesia during femoral canal preparation and cementation can result in unrecognized cardiovascular collapse 1
• Using intramuscular opioids causes unnecessary injection-associated pain and should be avoided 1
• NSAIDs increase intra-operative and postoperative blood loss risk in THR patients, so monitor accordingly 1