Primary hip arthroplasty

1. High-Yield Summary

Primary total hip arthroplasty (THA) is the definitive surgical reconstruction of the coxofemoral articulation, replacing the diseased acetabulum and proximal femur with prosthetic components to relieve pain, restore joint biomechanics, correct deformity, and re-establish functional independence.

• Primary Clinical Indication: Intractable hip pain and progressive functional disability resulting from end-stage degenerative joint disease (primary osteoarthritis, post-traumatic osteoarthritis, avascular necrosis with femoral head collapse, or inflammatory arthropathy) refractory to exhaustive nonoperative management for at least three to six months, or acute displaced intracapsular femoral neck fractures in active geriatric patients.
• The Critical Move: Accurate reconstruction of the anatomical hip center of rotation by optimizing acetabular cup orientation (40 to 45 degrees inclination, 15 to 25 degrees anteversion) and matching native femoral neck-shaft angle, version, and horizontal offset, thereby avoiding prosthetic or bony impingement and maintaining equal limb lengths.
• Catastrophic Errors to Avoid: Component malposition causing recurrent instability or edge-loading; occult intraoperative proximal femoral burst fracture during compaction broaching or stem insertion; acetabular medial wall over-reaming past the teardrop; and neurovascular traction or laceration injury involving the sciatic, femoral, or obturator bundles from misplaced retractors.

2. Indications

Indications for primary total hip arthroplasty require strict correlation between documented radiographic pathology, functional limitations, and clinical failure of nonoperative protocols.

• Absolute Indication – End-Stage Degenerative Joint Disease: Advanced coxarthrosis (Kellgren-Lawrence Grade 3 or 4) with bone-on-bone contact, subchondral sclerosis, osteophyte formation, or geode development associated with debilitating pain and physical disability refractory to exhaustive nonoperative modalities.
• Absolute Indication – Osteonecrosis of the Femoral Head: Avascular necrosis with structural subchondral collapse (Ficat and Arlet Stage III or IV, Steinberg Stage IV to VI).
• Absolute Indication – Displaced Femoral Neck Fractures: Acute displaced intracapsular fractures (Garden Type III or IV) in physiologically active, cognitively intact community-ambulating elderly patients.
• Absolute Indication – Secondary Coxarthrosis: Severe secondary osteoarthritis following childhood hip disease (developmental dysplasia of the hip, slipped capital femoral epiphysis, Legg-Calve-Perthes disease) with symptomatic joint destruction.
• Relative Indication – Early Post-Collapse Osteonecrosis: Symptomatic avascular necrosis in younger patients where joint-preserving osteotomies or core decompression have failed or are anatomically contraindicated.
• Relative Indication – Rapidly Destructive Coxarthrosis: Rapid chondrolysis and osteolysis without neurological deficit causing severe joint collapse.
• Relative Indication – Fixed Spinopelvic Imbalance: Severe functional limitation with moderate radiographic findings in the setting of documented significant pelvic tilt or rigid spinopelvic imbalance.
• Absolute Contraindications: Active local joint sepsis or systemic bacteremia; severe active infection in remote sites (dental abscess, urinary tract infection, infected skin ulcers); complete absence or denervation of the functional abductor mechanism (for standard unconstrained bearings); rapidly progressive neurological disease; severe medical comorbidities precluding safe anesthesia.
• Relative Contraindications: Severe unmanaged medical comorbidities (uncontrolled diabetes with HbA1c >8.0%, morbid obesity with BMI >40 kg/m², end-stage renal disease on hemodialysis); active tobacco/nicotine use; neuropathic (Charcot) arthropathy; non-compliance or cognitive impairment that prevents adherence to perioperative precautions.

3. Preoperative Planning

Imaging Review

Accurate digital or 2D/3D templating relies on standardized radiographic views and pelvic landmark identification:

• Low-Centered AP Pelvis: Centered over the superior margin of the pubic symphysis with bilateral lower limbs positioned in 15 degrees of internal rotation to counteract femoral anteversion. Allows precise measurement of the anatomical teardrop, ilioischial line (Kohler line), sacroiliac joint orientation, abductor lever arm, and native limb length discrepancy (comparing the inter-teardrop line to the lesser trochanters).
• True Shoot-Through Cross-Table Lateral: Evaluates native femoral version, anterior and posterior acetabular rim bone stock, and femoral head sphericity without requiring painful manipulation of the arthritic hip.
• Spinopelvic Radiographs (Standing and Seated Lateral): Indicated in patients with prior lumbar spinal fusion, advanced degenerative lumbar spondylosis, or significant spinal deformity. Evaluates sacral slope change (delta SS) between standing and relaxed seated postures to distinguish flexible, stiff, or hypermobile spinopelvic phenotypes, guiding targeted adjustment of functional acetabular cup anteversion to prevent edge-loading and dislocation.
• Proximal Femoral Canal Morphology (Dorr Classification): Assesses canal taper to select femoral stem geometry. Dorr Type A (champagne-flute, thick cortices) requires careful canal broaching to avoid bursting fractures; Dorr Type B represents normal taper; Dorr Type C (cylindrical “stovepipe” canal with thin cortices) suggests higher risk of early subsidence with standard tapered wedges, favoring cemented fixation or specialized fully coated designs.

Equipment Checklist

The operative suite must have verified access to specialized instrumentation and multi-tier component back-ups:

• Specialized Hip Retractors: Curved Hohmann retractors, blunt cobra retractors, anterior acetabular wall retractor, inferior retractor for sub-transverse ligament placement, and self-retaining retractor systems (Charnley, Beckman, or Mueller).
• Bone Preparation Power Tools: High-torque battery/pneumatic oscillating saw with dedicated hip saw blades; spherical acetabular reamers (incremental sizes from 40 mm to 64 mm); straight and curved starter gouges; box osteotome; modular femoral broaches with calcar planers.
• Prosthetic Implants: Porous-coated hemispherical titanium shells (solid and multi-hole); 6.5 mm cancellous dome screws with matching flexible screwdrivers; highly cross-linked polyethylene (HXLPE) liners (neutral, 10-degree elevated lip, and face-changing options) and ceramic liners; cementless hydroxyapatite or porous-coated tapered-wedge femoral stems (standard and high-offset options); modular ceramic and cobalt-chromium heads (28 mm, 32 mm, 36 mm, 40 mm) with varying neck offsets (-3.5 mm to +10.5 mm); backup cemented stems and antibiotic cement.
• Consumables and Hemostatic Adjuncts: Intravenous tranexamic acid (TXA); high-tensile braided non-absorbable sutures (#2 and #5 Ethibond or FiberWire) for transosseous soft-tissue repair; barbed knotless absorbable sutures for fascial closure; pulsatile irrigation systems; bone wax and topical hemostatic matrix.

Examination Under Anesthesia (EUA)

Following successful administration of regional or general anesthesia and prior to skin antisepsis, perform a structured EUA:

• Range of Motion and Contracture Assessment: Measure maximum passive flexion, extension, abduction, and adduction. Perform a modified Thomas test to identify fixed flexion contracture of the ipsilateral hip. Check for fixed adduction or abduction contractures that may alter intraoperative leg length perception.
• Direct Clinical Leg Length Comparison: Palpate bilateral anterior superior iliac spines (ASIS), patellae, and medial malleoli. Place both limbs in identical abduction/adduction alignment to establish the baseline functional and anatomical leg length discrepancy.
• Abductor Mechanism Tone: Assess soft-tissue tension and myofascial compliance under complete neuromuscular blockade.

4. Patient Positioning & Setup

Positioning depends on the planned surgical approach and must ensure rigid pelvic stability while protecting peripheral nerve contact points.

Lateral Decubitus Positioning (Posterior, Direct Lateral, Anterolateral Approaches):

• Pelvic Fixation Rigidity: Position the patient on the operative table with the operative hip facing upward. Secure the pelvis rigidly using an adjustable pegboard, padded anterior pubic/sternal posts, and posterior sacral/scapular posts, or a conforming vacuum beanbag.
• Brachial Plexus Decompression: Place an axillary roll inferior to the dependent axilla to protect the brachial plexus. Ensure the dependent ear and eye are completely uncompressed.
• Peroneal Nerve Cushioning: Pad the dependent fibular head and lateral malleolus with gel pads to prevent common peroneal nerve palsy. Place pillows or large gel bolsters between the lower extremities.
• Pelvic Perpendicularity: Align the pelvis strictly perpendicular (90 degrees) to the floor. Prevent inadvertent anterior pelvic tilt, which can deceptively lead the surgeon into retroverting the acetabular component.

Supine Positioning (Direct Anterior Approach):

• Radiolucent Traction Table: Position the patient supine on a specialized radiolucent traction table (such as a Hana table) or a standard radiolucent table with mobile leg spar.
• Perineal and Boot Padding: Secure the feet in padded traction boots. Place the perineal post with abundant padding to prevent pudendal nerve injury. Ensure bilateral anterior superior iliac spines (ASIS) are horizontal and level.
• Upper Extremity Corridors: Tuck bilateral upper extremities in neutral padding alongside the thorax, ensuring unobstructed fluoroscopic arcs.

Safety Check

Prior to sterile draping, execute mandatory positioning verification steps:

• Pelvic Stability Stress Test: Apply firm manual anterior and posterior directed forces across the iliac crest and sacrum. Confirm zero pelvic toggle or slippage within the positioner.
• Imaging Clearance Check: For anterior or fluoroscopy-assisted approaches, swing the C-arm across the pelvis and proximal femur to verify unobstructed sterile AP and lateral visualization corridors prior to incision.
• Limb Mobilization Arc: Verify that the operative limb can achieve unhindered internal rotation, external rotation, adduction, and hyperextension within the sterile field.

5. Approach

Surgical exposure must exploit safe intermuscular and internervous planes, respect neurovascular danger zones, and preserve musculotendinous envelopes to ensure rapid recovery and dynamic joint stability.

Detailed neurovascular danger corridors include:

• Sciatic Nerve Safe Corridor: Located posterior to the obturator internus and gemelli muscles, coursing down the posterior thigh. The nerve is at highest risk during posterior capsular exposure, aggressive acetabular retraction, and acute limb lengthening (>2 cm). Placing the knee in flexion relaxes sciatic nerve tension, and tagging the short external rotators creates a protective muscular buffer.
• Femoral Neurovascular Bundle: Lies anterior to the anterior acetabular wall, separated by the iliopsoas tendon and muscle belly. Retractors hooked over the anterior acetabular rim must be positioned directly subperiosteally on bone; placing retractors through the psoas belly or medially risks direct compression of the femoral nerve.
• Obturator Neurovascular Bundle & Corona Mortis: The obturator canal lies inferior to the acetabulum, and the corona mortis (aberrant anastomosis between external iliac/inferior epigastric and obturator vessels) crosses the superior pubic ramus. Retractors placed in the inferior acetabular notch must hug the inferior rim beneath the transverse ligament; drilling screw holes in the anterior quadrants of the acetabulum is strictly avoided to prevent life-threatening retroperitoneal bleeding.

6. Technique

Step 1: Exposure and Soft-Tissue Mobilization

Procedural sequence detailed for the posterior approach (the most widely utilized worldwide technique, with key variations noted):

• Incise: Make a gently curved skin incision centered over the posterior third of the greater trochanter, extending 6 to 8 cm proximally toward the posterior superior iliac spine along the gluteus maximus fibers, and 6 to 8 cm distally parallel to the femoral shaft.
• Mobilize Fascia: Incise the fascia lata distally in line with the skin incision. Extend the fascial division proximally by blunt splitting of the gluteus maximus muscle fibers along their natural pennation vector, controlling hemostasis of bleeding transmuscular branches of the inferior gluteal artery with bipolar cautery.
• Retract and Clear Bursa: Insert a Charnley or self-retaining retractor to spread the gluteus maximus. Excise the trochanteric bursa to clearly visualize the posterior border of the gluteus medius, the insertion of the piriformis, the conjoined tendon (obturator internus and gemelli), and the quadratus femoris.
• Tag and Release Rotators: Internally rotate the hip to put the short external rotators under tension. Identify the piriformis tendon and conjoined tendon. Place two heavy #2 braided non-absorbable stay sutures through their tendinous insertions for subsequent identification and repair. Sharply peel the tendons off the posterior trochanteric crest, leaving a small cuff of tissue on bone. Reflect the detached muscular flap medially over the sciatic nerve to serve as a protective soft-tissue shield. Maintain the quadratus femoris intact whenever possible to safeguard the underlying medial femoral circumflex artery.
• Capsulotomy: Expose the underlying posterior hip capsule. Perform a generous inverted T-shaped or broad-based H-shaped capsulotomy, peeling the capsular flaps superiorly and inferiorly off the acetabular rim. Place stay sutures in the capsular flaps for subsequent transosseous closure.
• Dislocate: Gently dislocate the femoral head by placing the limb into progressive flexion, adduction, and internal rotation. Apply gentle axial traction and manual pressure; avoid extreme levering maneuvers against the femoral shaft to prevent spiral periprosthetic fractures.

Step 2: Bone Preparation / Debridement

Accurate bony preparation requires precise anatomical referencing of both acetabular and femoral geometry:

• Femoral Neck Resection Marking: Expose the anterior and posterior femoral neck. Measure the resection height above the superior border of the lesser trochanter using preoperatively templated cutting guides (typically 10 to 15 mm proximal to the lesser trochanter). Mark the osteotomy line with electrocautery, angling approximately 40 to 45 degrees relative to the femoral diaphyseal axis aimed toward the piriformis fossa.
• Femoral Neck Osteotomy Execution: Complete the osteotomy using an oscillating saw cooled with sterile saline irrigation to prevent thermal bone injury. Take special care at the posterosuperior exit to avoid notching the greater trochanter or abductor tendon insertion. Remove the resected femoral head using a corkscrew extractor.
• Acetabular Retractor Placement: Place three specialized retractors to visualize the acetabulum circumferentially: an anterior Hohmann retractor resting subperiosteally on the anterior acetabular wall; a curved posterior wall retractor displacing the proximal femur anteriorly; and a hooked inferior retractor positioned in the obturator foramen beneath the transverse acetabular ligament (TAL).
• Labral and Cotyloid Debridement: Excise the entire labrum circumferentially. Debride the pulvinar fat pad and ligamentum teres from the cotyloid fossa using a ring curette and electrocautery until the medial bony wall (lamina interna) is identified. Clearly expose the TAL at the inferior rim as the primary anatomical reference for cup anteversion.
• Sequential Acetabular Reaming: Begin with a small starter hemispherical reamer (e.g., 42 or 44 mm) directed medially toward the floor of the acetabular cotyle to establish the anatomical center of rotation down to the medial cortical floor without penetrating the inner pelvic cortex. Progress sequentially in 1 mm or 2 mm increments, orienting the reamer handle to replicate 40 to 45 degrees of operative inclination and 15 to 25 degrees of anteversion (parallel to the plane of the TAL). Ream until a uniform hemispherical bed of bleeding cancellous bone is achieved across the superior dome and anterior/posterior walls, while preserving supportive subchondral peripheral cortical bone rims.
• Femoral Canal Exposure and Alignment: Deliver the proximal femur into the wound by flexing the hip to 90 degrees, internally rotating to 90 degrees, and adducting the limb. Place a Mueller retractor beneath the lesser trochanter. Open the femoral canal at the posterosuperior junction of the femoral neck and greater trochanter using a box osteotome or starter gouge. Ensure adequate lateral bone removal from the trochanteric shoulder to allow a straight-line axial entry vector, preventing varus stem placement.
• Compaction Broaching: Pass a starter canal finder along the long axis of the diaphysis. Progressively broach with compaction rasps of increasing sizes, aligning each broach with 10 to 15 degrees of native femoral anteversion relative to the posterior condyles. Palpate the anterior femoral neck during insertion to verify central containment and prevent anterior cortical perforation. Broach until achieving stable axial and rotational seating (“cortical chatter”). Planer the calcar smooth if required for calcar-seating stems.

Step 3: Trialing and Provisional Fixation

Provisional trialing validates stability, leg length equality, and horizontal femoral offset prior to committing to final components:

• Acetabular Shell and Liner Trialing: Seat the trial acetabular shell corresponding to the final reamed diameter. Confirm 360-degree rim contact and absence of bottoming out. Verify proper inclination (40 to 45 degrees) and anteversion (15 to 25 degrees). Snap in the trial polyethylene liner.
• Femoral Trial Assembly: Maintain the final broach in the canal as the femoral trial base. Attach the preoperatively templated trial modular neck (standard vs. high-offset) and a trial modular femoral head (e.g., standard +0 offset).
• Posterior Instability Challenge: Reduce the hip joint with gentle longitudinal traction and external rotation. Flex the hip to 90 degrees, adduct to 10-15 degrees, and internally rotate to 40-45 degrees. The hip must remain completely stable without posterior subluxation, and there must be no prosthetic neck-on-liner or anterior bony impingement.
• Anterior Instability Challenge: Fully extend the hip, externally rotate to 40 degrees, and apply extension traction. Confirm absence of anterior subluxation or posterior trochanteric/ischial bony impingement.
• Shuck (Traction) Test: Apply vigorous axial distraction to the femur. A normal balanced reconstruction demonstrates 1 to 2 mm of elastic displacement with crisp snap-back recoil. Excessive displacement (>3 mm) indicates inadequate offset or length; zero displacement with high joint resistance suggests over-lengthening and excessive abductor tension.
• Leg Length and Offset Verification: Palpate bilateral patellae and medial malleoli; assess tension of the conjoined tendon and anterior capsule; measure the distance from the lesser trochanter to the head center against the preoperative template.

Step 4: Final Implant Placement or Suture Fixation

Implantation follows a strict irreversible sequence requiring pristine component preparation and secure biological fixation:

• Definitive Acetabular Shell Impaction: Irrigate the acetabular bed thoroughly. Mount the definitive porous-coated press-fit cup (typically sized 1 mm larger than the last reamer for press-fit stability) onto the impactor handle. Align the cup at 40 to 45 degrees of inclination and 15 to 25 degrees of anteversion, referencing the plane of the TAL. Impact firmly with a heavy mallet until a solid, low-pitched acoustic tone confirms rigid seating against bleeding cancellous bone. Inspect through the apical dome screw hole to verify that no polar gap exists between the inner shell surface and the medial acetabular floor.
• Supplemental Posterosuperior Screw Placement: If supplemental screw fixation is desired or required due to compromised bone quality, drill pilot holes through the posterosuperior quadrant (“safe zone”) directed toward the sacroiliac joint, measure depth, and insert 6.5 mm cancellous bone screws, countersinking their heads flush with the shell.
• Liner Seating and Locking Engagement: Seat the definitive highly cross-linked polyethylene (HXLPE) or ceramic liner into the shell. Confirm that the locking mechanism engages circumferentially without soft-tissue interposition.
• Definitive Femoral Stem Insertion: Irrigate and aspirate the femoral canal. Insert the definitive cementless tapered-wedge stem matching the size of the final broach. Guide the stem along the prepared axial trajectory, maintaining 10 to 15 degrees of anteversion. Impact the stem using controlled, progressive hammer strikes until the collar or shoulder reaches the exact level established by the final broach, producing a resonant cortical tone. Confirm rotational stability.
• Modular Head Engagement: Thoroughly clean and dry the Morse taper trunnion, removing all blood, bone debris, and fluid. Place the definitive modular ceramic or cobalt-chromium head onto the trunnion. Engage the taper with a firm push-and-twist motion, followed by a solid axial mallet strike using a protected head impactor.
• Transosseous Soft-Tissue Reconstruction: Irrigate the articulation copiously with warm saline to eliminate all particulate debris. Gently reduce the prosthetic joint with axial traction. Re-confirm full range-of-motion stability. Perform an anatomical transosseous capsulotendinous repair: drill two or three 2.5 mm transosseous tunnels through the posterior trochanteric crest. Pass the heavy #2 braided stay sutures from the posterior capsule and conjoined tendon (piriformis, obturator internus, and gemelli) through the drill holes. Tie the sutures down securely while holding the limb in 15 degrees of abduction, extension, and neutral rotation.
• Anatomical Layered Closure: Close the fascia lata with running barbed or heavy absorbable sutures in a watertight fashion. Close subcutaneous fat in layers and approximate skin with subcuticular sutures or staples.

Critical Move

The irreversible procedural step (“point of no return”) in primary total hip arthroplasty is the definitive impaction of the acetabular cup and the final rotational trajectory of the femoral stem:

• Cup Orientation Triangulation: Visual alignment guides reference the operating room floor and walls, which can be profoundly misleading if the patient has tilted forward in the lateral position. Set cup anteversion parallel to the Transverse Acetabular Ligament (TAL) with 10 to 15 degrees of additional anterior inclination relative to the ligament plane, ensuring 15 to 25 degrees of true anatomical anteversion. Verify 40 to 45 degrees of operative inclination by referencing the inferior teardrop and superior cotyloid rim, ensuring 2 to 3 mm of native anterior and posterior bone overhang to confirm complete containment.
• Combined Anteversion Rule: Ensure that the sum of acetabular cup anteversion and femoral stem anteversion falls strictly between 25 and 35 degrees (Ranawat safe zone). If femoral anatomy forces a retroverted or excessively anteverted stem trajectory, the acetabular cup version must be proactively adjusted before final impaction to prevent mechanical impingement.
• Acoustic and Tactile Feedback During Stem Impaction: During final stem seating, recognize changes in acoustic pitch. A drop in pitch or sudden loss of resistance signals a cortical fracture of the calcar or greater trochanter. If a hoop stress hairline crack occurs, immediately stop impaction, place a prophylactic cerclage cable around the proximal femur, and verify stable stem fixation.

7. Pearls and Pitfalls

Pearls

• TAL Referencing for Pelvic Tilt Immunity: The Transverse Acetabular Ligament (TAL) is an internal landmark that moves synchronously with the pelvis. Referencing the TAL provides patient-specific anteversion independent of whether the pelvis has rolled into anterior or posterior tilt on the table.
• Lateralize the Femoral Entry Portal: Always use the box osteotome to aggressively clear the lateral cortical overhang of the greater trochanter at the piriformis fossa. A medialized entry drives the broach down into varus, increasing shear stresses and predisposing to medial calcar fracturing or early femoral loosening.
• Offset Restoration Over Modular Neck Lengthening: When addressing joint laxity during trial reduction, first optimize horizontal femoral offset by switching to a high-offset stem geometry rather than simply increasing head/neck length. Restoring offset retensions the abductor lever arm without lengthening the operative limb.
• Meticulous Transosseous Posterior Repair: Anchoring the conjoined tendon and capsule directly through transosseous bone tunnels into the greater trochanter re-establishes a powerful posterior dynamic barrier, dramatically reducing posterior dislocation risks.
• Dual-Dose Tranexamic Acid (TXA): Administer 1 gram of IV TXA prior to incision followed by a second 1 gram dose at wound closure (or 2 grams total) to suppress fibrinolysis, reducing total perioperative blood loss by over 50% and virtually eliminating allogeneic blood transfusions.

Pitfalls

• The Pelvic Tilt Illusion: Patient positioning in the lateral decubitus position is dynamic; muscle relaxation under anesthesia commonly causes the pelvis to tilt forward (anterior tilt). Aligning the cup to external room coordinates under unrecognized pelvic tilt results in severe functional cup retroversion and verticality, causing posterior dislocation.
• Over-Reaming the Medial Wall: In osteopenic or female acetabula, overzealous reaming past the teardrop breaches the lamina interna, causing intrapelvic cup migration, loss of peripheral press-fit, and danger of retroperitoneal vascular injury. Stop medial reaming as soon as the floor of the cotyloid fossa is lightly decorticated.
• Anterior Femoral Cortical Perforation: The femoral neck and anterior diaphysis bow anteriorly. Introducing starter broaches in an anteriorly directed trajectory can punch directly through the thin anterior femoral cortex. Always palpate the anterior femoral neck during broaching to ensure central instrument containment.
• Sciatic Nerve Traction Injury from Over-Lengthening: Lengthening the limb by more than 2 cm to compensate for soft-tissue laxity stretches the peroneal and tibial divisions of the sciatic nerve, causing postoperative foot drop. If nerve tension is suspected postoperatively, immediately place the patient with the knee flexed and hip extended.

8. Postoperative Care

Immediate

• Weight-Bearing Status: Full weight-bearing as tolerated (WBAT) immediately on postoperative day 0 with crutches or a walker under supervised physical therapy. Modern press-fit and cemented implants achieve immediate mechanical stability capable of supporting full body weight.
• Thromboprophylaxis Protocol: Initiate multimodal venous thromboembolism (VTE) prophylaxis within 12 to 24 hours postoperatively. For standard-risk patients: Aspirin 81 mg twice daily for 4 to 6 weeks combined with pneumatic sequential compression devices during hospital rest. For high-risk patients (history of VTE, active malignancy, morbid obesity): Direct oral anticoagulants (apixaban 2.5 mg BID or rivaroxaban 10 mg daily) or low-molecular-weight heparin for 28 to 35 days.
• Multimodal Pain Management: Opioid-sparing analgesia integrating local infiltration analgesia (LIA), scheduled oral acetaminophen (1000 mg every 8 hours), oral NSAIDs (celecoxib 200 mg daily), and short-course gabapentinoids, minimizing opioid-related nausea, sedation, and urinary retention.

Rehabilitation Protocol

Modern Enhanced Recovery After Surgery (ERAS) pathways eliminate obsolete rigid movement restrictions while guiding progressive functional recovery across four defined phases:

9. Outcome

Primary total hip arthroplasty delivers exceptional, reproducible long-term survivorship and functional restoration, established across national joint replacement registries and prospective clinical trials:

• Long-Term Implant Survivorship: Data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), the UK National Joint Registry (NJR), and the Swedish Hip Arthroplasty Register consistently demonstrate 15- to 20-year all-cause revision-free implant survivorship of 90% to 95%. When utilizing modern uncemented porous shells with highly cross-linked polyethylene (HXLPE) or ceramic bearings, survivorship against aseptic loosening exceeds 96% at 15 years.
• Patient-Reported Outcome Measures (PROMs): THA produces among the highest improvements in health-related quality of life across all surgical disciplines. Validated scoring instruments, including the Harris Hip Score (HHS), Hip disability and Osteoarthritis Outcome Score (HOOS), Oxford Hip Score (OHS), and EQ-5D, demonstrate dramatic pain relief and functional restoration, with over 90% of patients achieving good-to-excellent results.
• Registry Survivorship by Approach and Fixation: National registries indicate that while cementless femoral stems dominate North American practice with excellent outcomes in Dorr Type A and B bone, cemented femoral fixation maintains superior survivorship and lower periprosthetic fracture rates in patients aged 75 years and older with Dorr Type C osteoporotic bone. When performed with anatomical soft-tissue repair, long-term revision rates between posterior, direct anterior, and anterolateral approaches show no statistically significant difference at 10 years.

10. Complications

Anticipation, early recognition, and structured mitigation strategies protect patient safety and implant survivorship:

11. Evidence-Based Synthesis

Modern clinical decision-making is grounded in high-quality randomized controlled trials and prospective registry analyses, corroborated by seminal biomechanical and anatomical descriptions.

12. References

• Saueressig T, Owen PJ, Zebisch J et al. Evaluation of Exercise Interventions and Outcomes After Hip Arthroplasty: A Systematic Review and Meta-analysis. JAMA Netw Open. 2021. doi:10.1001/jamanetworkopen.2021.0254 [Level I: Systematic Review / Meta-Analysis]
• Zhang Q, Chen Y, Li Y et al. Enhanced recovery after surgery in patients after hip and knee arthroplasty: a systematic review and meta-analysis. Postgrad Med J. 2024. doi:10.1093/postmj/qgad125 [Level I: Systematic Review / Meta-Analysis]
• Korfitsen CB, Mikkelsen LR, Mikkelsen ML et al. Hip precautions after posterior-approach total hip arthroplasty among patients with primary hip osteoarthritis do not influence early recovery: a systematic review and meta-analysis of randomized and non-randomized studies with 8,835 patients. Acta Orthop. 2023. doi:10.2340/17453674.2023.11958 [Level I: Systematic Review / Meta-Analysis]
• Steven Michael Kurtz, Kevin L. Ong, Edmund Lau et al. Projections of Primary and Revision Hip and Knee Arthroplasty in the United States from 2005 to 2030. Journal of Bone and Joint Surgery. 2007. doi:10.2106/jbjs.f.00222 [Level V (Expert Conceptual Review): Seminal Conceptual / Observational Study]

13. Master Class Pro-Tip

When restoring hip stability during primary total hip arthroplasty, never attempt to resolve soft-tissue laxity simply by selecting a longer modular neck length. Increasing neck length lengthens the extremity vertically and tensions the myofascial sleeve, but does not address a deficiency in horizontal femoral offset. If the trial construct exhibits laxity, dislocates in extension and external rotation, or demonstrates soft-tissue pistoning, first confirm that the acetabular cup is fully seated at 40 to 45 degrees of inclination and 15 to 25 degrees of anteversion. Next, switch from a standard neck to an extended high-offset femoral stem. Lateralizing the femoral shaft restores the native abductor moment arm, tensions the abductor musculature across its true vector without lengthening the operative limb, and eliminates bony impingement between the greater trochanter and the ilium, achieving rock-solid biomechanical stability while maintaining exact limb length equality.

Master Class Surgical Pearl: Primary Total Hip Arthroplasty