import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Location**: Exits greater sciatic notch 10-20mm posterior to posterior column, travels 15mm lateral to ischial tuberosity **Protection**: Identify early with finger palpation, maintain retractor on lesser trochanter, avoid combined hip flexion and retraction posteriorly, assess with intraoperative monitoring if performing extensive posterior column work **Location**: Exits pelvis through suprapiriform foramen 30-40mm superior to acetabular rim, between gluteus medius and minimus **Protection**: Stay distal to gluteus medius insertion, limit superior dissection to 4-5cm above acetabular rim, use Charnley retractor positioned carefully if extending exposure superiorly **Location**: Lie 10-20mm medial to pelvic brim along iliopsoas, vulnerable during medial wall perforation or screw placement into anterior column **Protection**: Drill stop technique for all anterior column screws (25-30mm maximum depth), avoid medial wall protrusion, confirm screw trajectory with fluoroscopy, assess vessel position on preoperative CT **Location**: Travels along obturator foramen 15-25mm medial to quadrilateral plate, at risk during ischial screw placement and medial reaming **Protection**: Ischial screws directed posteroinferiorly (away from foramen), limit medial reaming depth, use curved osteotomes away from quadrilateral plate **Location**: Lies 20-30mm inferior and medial to AIIS along iliopsoas, vulnerable during anterior approaches and anterior column screw placement **Protection**: Gentle medial retraction with tagged vessels if using ilioinguinal approach, verify anterior column screw length (maximum 30mm), maintain capsule integrity when possible ## Primary Indications **Paprosky Type II Defects** - Moderate bone loss with intact columns - Superior migration less than 2cm - Cavitary or contained segmental defects - Distorted but identifiable acetabular landmarks - 40-60% bone stock remaining **Paprosky Type IIIA Defects** - Superior migration 2-3cm above obturator line - Loss of anterosuperior or posterosuperior rim - Kohler's line intact (medial wall competent) - Less than 50% bone stock but columns intact - Teardrop still identifiable **Additional Indications** - Recurrent instability requiring larger head/cup combination - Failed constrained liner requiring dual mobility - Periprosthetic osteolysis with progressive bone loss - Aseptic loosening with acceptable bone deficiency - Metallosis with pseudotumor requiring extensive debridement ## Contraindications **Absolute** - Active infection (requires staged protocol) - Pelvic discontinuity (Type IIIB - requires reconstruction cage or custom implant) - Superior migration more than 4cm (biomechanical center too high) - Non-reconstructible columns requiring structural allograft - Medical unfitness for major revision surgery **Relative** - Severe osteoporosis compromising screw purchase - Previous radiation therapy to pelvis - Neurologic disorders affecting compliance with protected weight-bearing - Severe soft tissue compromise from previous surgeries - Young active patient (biological reconstruction preferred when possible) ## Paprosky Classification System **Type I** - Intact bone stock with minor defects, standard cementless cup appropriate **Type II** - Moderate bone loss - IIA: Superior and medial intact, cavitary defects - IIB: Medial wall compromised, superior migration less than 2cm - IIC: Moderate superior and lateral defects **Type IIIA** - Severe superolateral deficiency - Superior migration 2-3cm - Ischium and teardrop intact - Less than 50% host bone contact achievable **Type IIIB** - Severe deficiency with pelvic discontinuity - Superior migration more than 3cm or discontinuity - Kohler's line disrupted - Requires reconstruction cage or custom triflange ## Imaging Assessment **Radiographic Analysis** - AP pelvis with obturator oblique views - Hip-center superior migration measured from inter-teardrop line - Kohler's line integrity (medial wall assessment) - Anterior and posterior column continuity - Residual cement or bone loss pattern - Heterotopic ossification classification (Brooker) **CT Protocol** - Fine-cut (1-2mm) with 3D reconstruction - Metal artifact reduction sequences - Bone stock quantification - Safe screw trajectory planning - Augment size and position templating - Vascular anatomy mapping (external iliac proximity) **Additional Studies** - Aspiration if ESR/CRP elevated (exclude infection) - SPECT-CT if bone viability questioned - Vascular imaging if iliac vessel injury suspected - MRI for soft tissue assessment (abductor integrity) ## Template Planning **Cup Sizing** - Measure native acetabulum on contralateral side - Plan for 4-8mm oversizing (jumbo definition) - Typical sizes: 62-70mm for most revisions - Consider dual mobility option for high dislocation risk **Augment Selection** - Superior rim defect: 30-50mm oblique wedge augment - Posterosuperior: 45-degree augment common - Multiple small augments preferable to single large - Trabecular metal allows immediate screw fixation **Screw Trajectory Planning** - Dome screws: 30-40mm into superior ilium - Ischial screws: 25-35mm into posterior column - Avoid anterior column (vascular risk) - Plan 4-6 screws minimum for jumbo cups ## Patient Optimization **Medical Clearance** - Cardiac risk stratification for prolonged surgery - Anemia correction (target Hgb more than 110 g/L) - Nutritional assessment (albumin, prealbumin) - Diabetic control (HbA1c less than 7%) **Infection Screening** - ESR, CRP, IL-6 (if available) - Aspiration if inflammatory markers elevated - Alpha-defensin or leukocyte esterase if equivocal - Dental clearance for elective revision **Thromboprophylaxis Planning** - Extended duration prophylaxis (35 days) - Consider inferior vena cava filter if previous VTE - Aspirin alone insufficient for revision surgery - Regional anesthesia consultation for neuraxial techniques ## Positioning and Preparation **Patient Position** - Lateral decubitus for posterior/posterolateral approach (most common) - Supine for anterior approach or anterolateral - Bean bag with pelvic supports secured - All pressure points well padded - Fluoroscopy capability available **Surgical Approach Selection** - Previous incision approach preferred when possible - Posterior approach: most versatile for acetabular revision - Extended trochanteric osteotomy if femoral revision concurrent - Trochanteric slide if superior/lateral exposure needed - Ilioinguinal approach for anterior column plating (rare) **Field Preparation** - Waterproof adhesive drape to prevent skin strike-through - Double glove technique with planned change after extraction - Antibiotic-impregnated drape if available - Cell saver setup for blood conservation - Ensure adequate lighting and retractor options ## Detailed Operative Steps ### Step 1: Exposure via Previous Incision **Technique**: - Utilize previous incision when possible to minimize soft tissue trauma - Extend proximally or distally as needed (avoid parallel incisions) - Sharp dissection through scar tissue layers - Identify and protect lateral femoral cutaneous nerve superiorly - Develop interval through gluteus maximus split or in line with fibers **Anatomical Considerations**: - Abductor mechanism often scarred to lateral pelvis - Piriformis and short external rotators may be attenuated or absent - Previous capsule typically adherent to cup or excised - Heterotopic bone may limit exposure (staged excision after component removal) **Technical Tip**: Plan incision extension before starting - insufficient exposure causes iatrogenic injury. If significant heterotopic ossification present, consider removing after component extraction to improve access. Trochanteric osteotomy gives superior exposure but adds complexity. - Skin necrosis from excessive tension (allow 1-2cm undermining only) - Neurovascular injury during deep dissection through scar - Abductor avulsion if excessive traction on scarred tissue ### Step 2: Capsulectomy and Pseudocapsule Excision **Technique**: - Systematic circumferential excision of fibrous pseudocapsule - Preserve abductor insertion on greater trochanter when intact - Tag any remaining capsular tissue for later repair if substantial - Release adhesions between femoral neck and acetabular rim - Expose acetabular component from rim to rim **Specimen Management**: - Send at least 5 tissue samples for culture (aerobic, anaerobic, fungal) - Separate instruments after excision (minimize contamination) - Membrane specimen for histology (wear debris analysis) **Technical Tip**: The pseudocapsule often contains high concentrations of wear debris and inflammatory mediator cells. Systematic excision reduces residual inflammatory burden and improves visualization. Send tissue before antibiotics if infection suspected based on preoperative workup. - Sciatic nerve injury if dissection extends too far posteriorly - Superior gluteal bundle if extending more than 4cm above rim - Femoral neck fracture if excessive traction on stiff hip ### Step 3: Femoral Head Removal and Dislocation **Technique**: - If isolated acetabular revision: dislocate hip gently - Apply traction with limb flexed 90 degrees and internally rotated - Lever femoral head anteriorly with curved retractor on posterior aspect - Once dislocated, deliver femoral neck into wound - Place Steinmann pin in proximal femur for retraction **Neck Resection** (if femoral revision concurrent): - Oscillating saw perpendicular to femoral axis - Cut at level of lesser trochanter initially - May require more proximal osteotomy if stem well-fixed - Protect posterior soft tissues with retractor during cutting **Technical Tip**: Stiff hips from massive heterotopic bone or bony ankylosis may require in situ neck osteotomy before dislocation attempt. This prevents iatrogenic femoral fracture. Gentle sequential release safer than forceful manipulation. - Periprosthetic femoral fracture from excessive force - Sciatic nerve traction injury - Greater trochanter avulsion in osteoporotic bone ### Step 4: Acetabular Component Extraction **Technique for Cementless Cup**: - Identify cup-bone interface with thin curved osteotomes - Work sequentially around entire periphery (360 degrees) - Use high-speed burr if osseointegration extensive - Gigli saw technique for well-fixed modular cups - Apply extraction device once mobilized (slap hammer or Explant system) **Technique for Cemented Cup**: - Remove polyethylene liner first (if modular) - Curved gouges between metal shell and cement mantle - Cement-cup interface often easier than cement-bone - Ultrasonic cement removal tools for residual mantle - Preserve bone stock - avoid aggressive curettage **Explant Device Application**: - Thread extractor into polyethylene screw holes - Progressive gentle taps (avoid sudden violent force) - Rock cup slightly to break final adhesions - Expect significant bone removal with extraction (plan for this) **Technical Tip**: Morcellize polyethylene liner before extraction if it prevents access to cup-bone interface. For well-fixed cups, Gigli saw passed behind cup through obturator foramen allows controlled cutting of posterior interface without explosive extraction that damages bone stock. - Pelvic discontinuity creation from aggressive extraction - Medial wall perforation (intrapelvic structures) - Anterior column fracture during vigorous osteotome use - Retained cement fragments in pelvis (embolization risk) ### Step 5: Cement and Membrane Removal **Technique**: - Systematic removal of all cement fragments and particulate debris - Ultrasonic cement removal system for adherent mantle - Curved curettes for fibrous membrane - Pulsatile lavage (3L minimum) between steps - Visualize bleeding healthy cancellous bone **Polyethylene and Metal Debris**: - Remove all visible polyethylene particles - Curettage of pseudotumor tissue if metallosis present - Particle-laden membrane extends beyond acetabulum - Consider synovectomy if extensive wear debris **Technical Tip**: Retained cement is a nidus for persistent inflammation and infection. Use sharp curettes rather than rongeurs (which push cement deeper). Ultrasonic tools allow precise cement removal without additional bone loss. Expect to spend 15-20 minutes on thorough debridement. - Intrapelvic cement extrusion causing vascular injury - Medial wall perforation during aggressive curettage - Heat injury to surrounding bone from ultrasonic devices ### Step 6: Bone Defect Assessment - Paprosky Classification **Systematic Evaluation**: - Superior migration: measure from inter-teardrop line - Kohler's line integrity: medial wall competency - Anterior column: palpate and assess continuity - Posterior column: finger palpation through sciatic notch - Rim deficiency: clock-face documentation (12-3 o'clock etc.) **Intraoperative Classification**: - Type II: Mild superior migration, distorted landmarks, cavitary or small segmental defects - Type IIIA: Moderate migration (2-3cm), rim defects but columns intact - Type IIIB: Severe migration, pelvic discontinuity, non-reconstructible **Documentation**: - Photograph bone defect for operative note - Measure defect dimensions with ruler (mediolateral, superoinferior) - Document Paprosky classification in dictation **Technical Tip**: Intraoperative classification may differ from radiographic assessment. Finger palpation gives best assessment of column integrity. If unsure whether IIIA or IIIB, stress test by levering on ischium - independent motion of ilium indicates discontinuity requiring cage or custom implant, not jumbo cup. - Unrecognized pelvic discontinuity leads to early failure - Overestimation of bone stock leads to undersizing - Anterior column fracture during aggressive palpation ### Step 7: Medial Wall and Dome Preparation **Sequential Hemispherical Reaming**: - Start 4-8mm larger than extracted cup size - Ream in 2mm increments to bleeding cancellous bone - Aim for 50-60% host bone contact minimum - Medialization acceptable to improve contact (up to anatomic center) - Final reamer typically 4-6mm smaller than planned cup **Medial Wall Management**: - Minor deficiencies: ream to bleeding bone - Moderate cavitary loss: impaction bone grafting - Major defects: mesh or augment reconstruction - Avoid excessive medialization (hip center biomechanics) **Dome Preparation**: - Superior bone typically best quality - Ream to expose cancellous bleeding surface - Multiple drill holes to enhance biological fixation - Avoid over-reaming (compromises screw purchase) **Technical Tip**: Jumbo cups defined as more than 4mm oversizing achieve press-fit through hoop stress. Typical progression: 60mm extractor to 66mm final reamer to 70mm cup. Maintain anatomic anteversion during reaming (10-20 degrees) - easy to drift into retroversion with sequential reaming of deficient anterosuperior rim. - Medial wall perforation into pelvis (intrapelvic structures) - Anterior column fracture from eccentric reaming force - Over-reaming compromises screw fixation into dome ### Step 8: Augment Application for Segmental Defects **Augment Selection**: - Superior rim defect: 30-50mm oblique wedge augment - Posterosuperior: 45-degree or 60-degree augment - Anterosuperior: 30-degree wedge most common - Trabecular metal preferred (immediate screw fixation) - Size to fill defect without proud overhang **Augment Fixation Technique**: - Trial augments to assess fit and stability - Multiple screws (minimum 2, ideally 3-4 per augment) - Screws divergent for maximum purchase - Bone graft behind augment to enhance biological incorporation - No cement between augment and bone (promotes ingrowth) **Multiple Augments**: - Several small augments preferable to single large - Independent screw fixation for each segment - Avoid gaps between augments (liner impingement risk) - Sequential trial reduction to verify stability **Technical Tip**: Trabecular metal augments allow immediate screw fixation and exhibit bone ingrowth within 6-12 weeks. Morcellized allograft packed behind augment enhances biological reconstruction. Augment position determines final cup orientation - place augment first, then trial cups to assess combined construct stability before final implantation. - Screw penetration into intrapelvic space (vessels) - Augment malposition causing liner impingement - Insufficient screw purchase leading to early loosening ### Step 9: Impaction Bone Grafting for Cavitary Defects **Graft Preparation**: - Morcellized allograft (fresh frozen preferred) - Particle size 5-10mm optimal - Autograft from femoral head if available - Mix with bone marrow aspirate to enhance biology **Impaction Technique**: - Contained defects suitable for impaction - Mesh or augment required if medial wall deficient - Sequential impaction with progressively larger trials - Achieve firm stable graft bed before cup insertion - Goal: reconstitute bone stock for biological fixation **Volume Assessment**: - Measure defect volume on 3D CT preoperatively - Typical requirement: 20-60mL morcellized graft - Over-pack slightly (20% consolidation expected) **Technical Tip**: Impaction grafting re-establishes bone stock for future revisions and provides biological substrate for cup ingrowth. Requires contained defect - use mesh if medial wall compromised. Sequential impaction with reverse reaming technique compacts graft optimally. Combined with jumbo cup oversizing, provides excellent long-term fixation even with substantial bone loss. - Graft extrusion into pelvis if wall deficient - Insufficient impaction leads to subsidence - Over-impaction causes pelvic fracture in osteoporotic bone ### Step 10: Jumbo Cup Trial and Assessment **Trial Cup Insertion**: - Insert trial cup with planned orientation - Assess stability with manual stress testing - Verify 50-60% host bone contact (minimum requirement) - Check rim deficiency coverage - Confirm no impingement on augments or bone **Orientation Assessment**: - Target inclination: 35-45 degrees (radiographic) - Target anteversion: 15-25 degrees (operative) - May accept non-anatomic version for stability - Computer navigation helpful but not mandatory - Intraoperative fluoroscopy to verify position **Stability Testing**: - Rock trial cup in multiple directions - Should be rigid with no gross motion - Micromotion acceptable (less than 150 microns) - If unstable: add screws, increase size, or add augments **Technical Tip**: Jumbo cups achieve fixation through peripheral hoop stress and screw augmentation, not complete host bone coverage. Acceptable to have superior deficiency if augments used and screw fixation adequate. Trial cups must replicate final implant thickness - use correct trial system. Computer navigation reduces malposition risk, particularly anteversion assessment. - Unrecognized instability leads to early failure - Malposition increases dislocation risk - Excessive inclination causes accelerated liner wear ### Step 11: Screw Trajectory Planning and Drilling **Safe Screw Zones**: - **Superior dome**: Excellent bone quality, screws into superior ilium 30-40mm - **Posterior dome**: Screws into posterior column and ischium 25-35mm - **Anterior dome**: AVOID - risk to external iliac vessels - **Posteroinferior quadrant**: AVOID - risk to sciatic nerve **Drilling Technique**: - Use drill guide through cup holes (prevents skiving) - Drill stop technique mandatory (set depth 3-5mm less than desired) - Feel for far cortex - bicortical purchase ideal - Irrigate during drilling to prevent thermal necrosis - Tap if bone dense (avoid crack propagation) **Screw Number and Size**: - Minimum 4-6 screws for jumbo cups - 6.5mm diameter most common (increased purchase) - Length: 25-45mm depending on location - Cluster screws in dome (maximum bone quality) - At least 2 ischial screws for rotational stability **Technical Tip**: Safe screw zones: superior (10-2 o'clock) and posterior (7-9 o'clock). Anterior screws (2-4 o'clock) risk external iliac vessels 10-20mm from inner table. Posteroinferior screws (5-7 o'clock) risk sciatic nerve. Dome screws should converge toward sacroiliac joint for maximum purchase. Fluoroscopy helpful to verify depth and trajectory, particularly in severe bone loss. - Intrapelvic vascular injury from anterior screws - Sciatic nerve injury from posteroinferior screws - Intraarticular screw penetration causing impingement - Crack propagation from excessive screw diameter ### Step 12: Final Jumbo Cup Implantation **Insertion Technique**: - Align cup with planned orientation marks - Sequential mallet impacts around periphery (avoid center) - Seat fully until rim flush with native bone - Maintain version during final impacts (easy to rotate) - Check stability - should be completely rigid **Press-Fit Assessment**: - Visual: circumferential bone contact at rim - Manual: no toggle or rotation with firm stress - Acoustic: solid thud (not hollow sound) - If inadequate: remove, increase 2mm, and re-insert **Screw Insertion**: - Insert all planned screws sequentially - Tighten to finger-tight, then quarter-turn (avoid over-tightening) - Locking screws if available (prevents backout) - Verify no prominent heads (liner impingement) **Technical Tip**: Final cup insertion requires controlled impacts distributed around periphery - central impacts cause rim deformation or fracture. Maintain orientation carefully - jumbo cups difficult to remove once seated. If primary stability inadequate despite appropriate sizing and screws, consider supplemental augments or alternative construct. Acceptable threshold: completely rigid to manual stress testing with no visible motion. - Cup fracture from excessive central impaction force - Pelvic fracture in severely osteoporotic bone - Version change during final seating impacts - Incomplete seating leaving gap (loosening risk) ### Step 13: Liner Selection and Insertion **Liner Options**: - **Standard polyethylene**: Low dislocation risk, young patients - **Dual mobility**: High dislocation risk (most common choice in revision) - **Constrained**: Last resort if dual mobility contraindicated - **Cemented polyethylene**: Alternative for jumbo cups (some systems) **Dual Mobility Rationale**: - Effective head size 36-40mm (increased jump distance) - Reduces dislocation rate from 10-15% to 2-5% in revision - Preferred for abductor deficiency, prior instability, neurologic disorders - No increased wear compared to standard bearings in modern designs **Liner Insertion**: - Clean taper thoroughly (debris prevents seating) - Align orientation markers (version control) - Impactor on polyethylene surface (not metal shell) - Verify full seating (no gap between liner and shell) - Check for secure locking mechanism engagement **Technical Tip**: Dual mobility liners are now standard in most acetabular revisions given substantially reduced dislocation rates without increased complications. Cemented polyethylene into jumbo metal shells provides alternative fixation when biological ingrowth uncertain (radiation, metabolic bone disease). Ensure adequate liner thickness (minimum 6-8mm) to prevent fracture and wear-through. - Malseated liner causes dissociation and dislocation - Insufficient polyethylene thickness leads to fracture - Wrong orientation increases impingement and instability ### Step 14: Trial Reduction and Stability Assessment **Systematic Stability Testing**: - Reduce hip with trial femoral head - Assess range of motion: flexion 90 degrees, internal rotation 30 degrees, external rotation 45 degrees - Stress testing in provocative positions (flexion-adduction-internal rotation) - Posterior approach: extension-external rotation stress - Should be stable throughout full arc **Leg Length and Offset**: - Compare to contralateral side clinically - Shuck test: less than 1cm translation acceptable - If excessively long: consider smaller head, alternative liner - If short: may need extended head or femoral revision **Impingement Testing**: - Full range stress in all planes - Feel and listen for bony or prosthetic impingement - Identify limiting factors (osteophytes, component malposition, soft tissue) - Address impingement before final implantation **Technical Tip**: Accept 5-10mm overlengthening in revision surgery - provides soft tissue tension that enhances stability. Excessive shortening (more than 10mm) correlates with dislocation and patient dissatisfaction. If unstable despite appropriate component positioning, consider: larger head, dual mobility, constrained liner, or femoral revision to adjust offset/version. Do not accept instability intraoperatively. - Unrecognized instability leads to early dislocation - Excessive leg lengthening causes nerve palsy - Impingement not addressed causes accelerated wear or fracture ### Step 15: Final Implantation and Wound Closure **Final Component Insertion**: - Clean all tapers and surfaces meticulously - Insert final liner with orientation verified - Reduce hip with definitive head - Final stability check (should replicate trial) - Intraoperative radiographs if available **Capsular Repair** (if tissue quality adequate): - Re-approximate posterior capsule to external rotators - Gluteus maximus repair to fascia lata - Enhanced closure reduces dislocation risk - Use non-absorbable suture (#2 Ethibond) **Abductor Repair**: - Trochanteric slide/osteotomy: secure fixation with cables or plate - Direct gluteus medius tear: anatomic repair to footprint - Tension-free repair mandatory (prevent re-rupture) **Layered Closure**: - Deep drain to pseudocapsule space (remove at 24-48h) - Fascia closed with #1 absorbable suture - Subcutaneous closure with 2-0 absorbable - Skin: staples or subcuticular (patient preference) - Sterile occlusive dressing **Technical Tip**: Meticulous soft tissue repair crucial for stability in revision arthroplasty. Posterior capsular repair reduces dislocation rate significantly. If tissue quality poor from multiple prior surgeries, consider Achilles tendon allograft augmentation of posterior structures. Deep drain prevents hematoma but remove early (risk of infection with prolonged drainage). Apply abduction brace if concerned about stability. - Inadequate soft tissue repair increases dislocation - Excessive drain output may indicate vascular injury - Wound closure under tension causes necrosis ## Additional Complications **Heterotopic Ossification** (20-40% incidence) - Higher risk in revision, trauma history, prior HO - Prophylaxis: Indomethacin 75mg daily for 6 weeks OR single-dose radiation (700 cGy) within 72h - Excision if symptomatic and mature (more than 12 months) **Leg Length Inequality** - Inevitable in reconstruction with superior migration - Acceptable: 5-10mm overlengthening for stability - Manage with shoe lift if more than 15mm discrepancy **Chronic Pain** - Multifactorial: nerve injury, bone pain, soft tissue trauma - Exclude infection and loosening first - Multimodal pain management, physical therapy - Neurogenic pain responds to gabapentin/pregabalin **Liner Dissociation** - Dual mobility specific complication (rare with modern designs) - Presents as instability or clicking - Requires liner revision or conversion to constrained ## Immediate Postoperative Management **Recovery Room Assessment**: - Neurovascular examination bilateral lower extremities - Assess sciatic and femoral nerve function immediately - Document motor and sensory status (medicolegal) - Pain control with multimodal analgesia - Hemoglobin check at 6-8 hours postoperatively **DVT Prophylaxis**: - LMWH (enoxaparin 40mg daily) or rivaroxaban 10mg daily - Extended duration: 35 days for revision surgery - Mechanical prophylaxis: sequential compression devices until ambulatory - Early mobilization (day 1) reduces VTE risk - Consider aspirin alone insufficient for revision **Wound Management**: - Deep drain removal at 24-48 hours (less than 30mL output) - Dressing change at 48 hours if drainage minimal - Suture/staple removal at 14-21 days (delayed for revision) - Monitor for persistent drainage (infection concern) ## Weight-Bearing Protocol **Standard Reconstruction** (adequate fixation, no concerns): - Toe-touch weight-bearing (10-15kg) for 6 weeks - Progress to partial weight-bearing (50%) weeks 6-12 - Full weight-bearing at 12 weeks after radiographic confirmation - Walker or crutches for first 6 weeks **Protected Reconstruction** (large defects, augments, concerning intraoperative stability): - Strict toe-touch for 12 weeks - Radiographic assessment at 6 and 12 weeks before progression - Partial weight-bearing weeks 12-16 - Full weight-bearing at 16-20 weeks if ingrowth confirmed **Abduction Brace**: - Consider for 6-12 weeks if dislocation risk high - Removes for therapy and hygiene only - Maintain 20-30 degrees abduction during sleep ## Hip Precautions **Posterior Approach Precautions** (12 weeks minimum): - No hip flexion more than 90 degrees - No adduction past midline - No internal rotation past neutral - Elevated toilet seat and chairs - Avoid low seating positions **Anterior Approach Precautions** (6-12 weeks): - No hip extension past neutral - No external rotation past 45 degrees - No combined extension-external rotation ## Radiographic Monitoring **Immediate Postoperative** (day 1-2): - AP pelvis and cross-table lateral - Assess component position and leg length - Document baseline for future comparison - Identify any intraoperative fractures **Follow-Up Schedule**: - 6 weeks: AP pelvis - assess early subsidence - 12 weeks: AP pelvis - confirm stability before full weight-bearing - 6 months: AP pelvis and lateral - assess ingrowth - 1 year: Complete radiographic series - Annually thereafter: Monitor for loosening, wear, osteolysis **Radiographic Red Flags**: - Subsidence more than 2mm (early failure predictor) - Progressive radiolucent lines - Component migration or rotation - Heterotopic bone formation interfering with ROM - Particulate wear or osteolysis development ## Physical Therapy Protocol **Phase 1 (0-6 weeks)**: Protected mobilization - Gait training with appropriate assistive device - Active-assisted range of motion - Isometric strengthening (gluteus medius activation) - No resistance exercises - Focus on precautions education **Phase 2 (6-12 weeks)**: Progressive strengthening - Advance weight-bearing as per protocol - Active range of motion all planes - Resistance band exercises (hip abduction, extension) - Pool therapy if available (reduces joint loading) - Proprioception and balance training **Phase 3 (12+ weeks)**: Functional restoration - Progressive resistance training - Normalize gait pattern - Return to activities of daily living - Cardiovascular conditioning - Avoid high-impact activities permanently ## Long-Term Considerations **Activity Modifications**: - Avoid high-impact sports (running, jumping) - Acceptable: Walking, swimming, cycling, golf - Monitor for accelerated wear with excessive activity - Weight management crucial for implant longevity **Surveillance**: - Annual clinical and radiographic assessment - Inflammatory markers if pain develops (exclude infection) - Metal ion levels if metallosis concern (MOM bearings) - DEXA scanning for osteoporosis management **Patient Education**: - Dislocation risk lifelong (particularly first 6 months) - Recognize infection symptoms (fever, drainage, pain) - Antibiotic prophylaxis for dental/invasive procedures controversial - Report new onset pain immediately ## References 1. Paprosky WG, Perona PG, Lawrence JM. Acetabular defect classification and surgical reconstruction in revision arthroplasty: a 6-year follow-up evaluation. J Arthroplasty. 1994;9(1):33-44. PMID: 8163974. **Seminal paper establishing Paprosky classification system for acetabular bone defects based on superior migration, column integrity, and teardrop presence - essential framework for surgical planning in acetabular revision**. 2. Ballester Alfaro JJ, Sueiro Fernandez J. Trabecular metal buttress augment and the trabecular metal cup-cage construct in revision hip arthroplasty for severe acetabular bone loss and pelvic discontinuity. Hip Int. 2010;20 Suppl 7:S119-127. PMID: 20512784. **Describes technique and outcomes of trabecular metal augments in severe acetabular deficiency - 94% survivorship at 5 years for Paprosky IIIA defects demonstrates effectiveness of biological fixation with porous tantalum**. 3. Sporer SM, Paprosky WG. Acetabular revision using a trabecular metal acetabular component for severe acetabular bone loss associated with a pelvic discontinuity. J Arthroplasty. 2006;21(6 Suppl 2):87-90. PMID: 16950068. **Outcomes of trabecular metal cups in severe acetabular deficiency including pelvic discontinuity - emphasizes importance of supplemental screw fixation and appropriate patient selection**. 4. Gill TJ, Sledge JB, Muller ME. The management of severe acetabular bone loss using structural allograft and acetabular reinforcement devices. J Arthroplasty. 2000;15(1):1-7. PMID: 10654454. **Describes reconstruction techniques for massive acetabular defects using structural allograft and reinforcement rings - establishes principles of restoring hip center and achieving biological fixation**. 5. Sembrano JN, Cheng EY. Acetabular cage survival and analysis of factors related to failure. Clin Orthop Relat Res. 2008;466(7):1657-1665. PMID: 18465182. **Systematic review of acetabular reconstruction cages showing 77% survivorship at 10 years - identifies protected weight-bearing and supplemental screw fixation as critical success factors**. 6. Garbuz DS, Morsi E, Mohamed N, Gross AE. Classification and reconstruction in revision acetabular arthroplasty with bone stock deficiency. Clin Orthop Relat Res. 1996;(324):98-107. PMID: 8595781. **Describes systematic approach to acetabular bone defect classification and reconstruction options based on defect type - emphasizes achieving biological fixation and reconstituting bone stock**. 7. Berry DJ, Lewallen DG, Hanssen AD, Cabanela ME. Pelvic discontinuity in revision total hip arthroplasty. J Bone Joint Surg Am. 1999;81(12):1692-1702. PMID: 10608380. **Landmark paper on pelvic discontinuity management - distraction technique with supplemental plating achieves union in 82% of cases with protected weight-bearing protocol**. 8. Guyen O, Pibarot V, Vaz G, Chevillotte C, Bejui-Hugues J. Use of a dual mobility socket to manage total hip arthroplasty instability. Clin Orthop Relat Res. 2009;467(2):465-472. PMID: 18780135. **Demonstrates dual mobility liners reduce dislocation rate from 15% to 3% in revision THA with high-risk features - now standard of care for acetabular revision in most centers**. 9. Regis D, Sandri A, Bonetti I, et al. A minimum of 10-year follow-up of the Burch-Schneider cage and bulk allografts for the revision of pelvic discontinuity. J Arthroplasty. 2012;27(6):1057-1063. PMID: 22226611. **Long-term outcomes of reconstruction cage with bulk allograft for pelvic discontinuity - 76% survivorship at 10 years emphasizes need for protected weight-bearing and supplemental fixation**. 10. Kosashvili Y, Backstein D, Safir O, Lakstein D, Gross AE. Acetabular revision using an anti-protrusion (ilio-ischial) cage and trabecular metal acetabular component for severe acetabular bone loss associated with pelvic discontinuity. J Bone Joint Surg Br. 2009;91(7):870-875. PMID: 19567848. **Cup-cage construct technique for pelvic discontinuity combining biological fixation potential of trabecular metal with structural support of cage - 93% survivorship at mean 4.6 years validates hybrid reconstruction approach**.

THA Revision - Acetabular Component (Jumbo Cup/Augments)

THA Revision - Acetabular Component (Jumbo Cup/Augments)