Ceramic Bearing Surfaces in Arthroplasty

Crystal Structure and Grain Architecture

Ceramic bearing surfaces are polycrystalline materials with hierarchical microstructure:

BIOLOX Delta Composite Architecture

BIOLOX Delta is an alumina matrix composite with engineered microstructure:

Zirconia platelet orientation:

• Platelets randomly oriented throughout alumina matrix
• When crack propagates, encounters zirconia platelets
• Transformation toughening: Stress at crack tip triggers tetragonal to monoclinic transformation in zirconia
• Volume expansion (3-5%) creates compressive stress that opposes crack opening
• Crack deflection: Crack forced to navigate around platelets (longer tortuous path dissipates energy)

Manufacturing Process and Microstructure Control

Hot Isostatic Pressing (HIP) Creates Optimized Microstructure:

Starting materials:

• Ultra-pure Al2O3 powder (99.99% purity raw material)
• Yttria-stabilized zirconia (Y-TZP) powder
• Chromium oxide and strontium oxide additives
• Mixing: Wet milling in ethanol for 24-48 hours ensures homogeneous distribution

Calcination: Heat to 1200C to remove organic binders and volatiles

Cold isostatic pressing (CIP):

• Powder compacted at 200-400 MPa pressure
• Forms "green body" (porous, fragile precursor)
• Relative density: 50-60% (significant porosity remains)

Pre-sintering: Heat to 1000-1200C to increase strength for handling

High-temperature sintering:

• Temperature: 1500-1800C (near melting point)
• Duration: 2-4 hours
• Diffusion-controlled densification: Atoms migrate to fill pore spaces
• Grain growth: Grains grow during sintering (must be controlled)

Chromium oxide role: Inhibits grain boundary mobility, limits grain growth to less than 0.5 microns

Simultaneous heat and pressure:

• Temperature: 1400-1600C
• Pressure: 100-200 MPa argon gas
• Duration: 2-4 hours
• Eliminates residual porosity: Achieves 99.9+ percent theoretical density
• Critical: Porosity is crack initiation site, HIP removes all pores greater than 1 micron

Result: Fully dense, homogeneous ceramic with optimized microstructure

Diamond machining:

• Ceramic extremely hard (harder than any metal tool)
• Requires diamond grinding wheels
• Precision: Tolerances less than 10 microns

Surface polishing:

• Diamond paste polishing
• Target surface roughness: Ra less than 0.01 microns (mirror finish)
• Significance: Smooth surface minimizes wear, prevents crack initiation

Defect Control and Quality Assurance

Potential microstructural defects:

Proof testing (quality control):

Every ceramic component undergoes proof testing before implantation:

• Burst pressure test: Hydraulic pressure to 150% anticipated in vivo stress
• Load to failure: Compressive load to 3-5x peak physiological load
• Rationale: Pre-existing flaws will cause failure during proof test, defective components rejected
• Pass rate: 99.5+ percent of manufactured components pass proof testing

Microstructure-Property Relationships

Classification by Ceramic Type

Ceramics used in arthroplasty classified by chemical composition:

Classification by Generation (Historical Evolution)

Classification by Bearing Combination

Key decision factors:

Advanced Classification: Material Properties

Detailed comparison of ceramic material classes:

Classification by Failure Mode

Understanding how different ceramics fail guides clinical decision-making:

Pure alumina (2nd generation):

• Fracture rate: 0.1-0.2%
• Mechanism: Brittle fracture from edge loading, impingement, or neck impaction
• Propagation: Once crack initiates, propagates catastrophically (no plastic deformation)
• Clinical presentation: Sudden pain, grinding, loss of function
• Management: Revision with complete synovectomy, remove all ceramic debris

BIOLOX Delta (4th generation):

• Fracture rate: 0.01-0.1% (10-fold lower)
• Mechanism: Same brittle fracture, but zirconia platelets deflect cracks, increase toughness
• Improved tolerance: Withstands higher edge loading stress before fracture
• Still catastrophic: Once fracture occurs, management same as pure alumina

Stripe wear (edge loading):

• Occurs when cup positioned too steep (greater than 50-55° inclination)
• Visible wear stripe at liner equator (concentrated contact zone)
• Wear rate increases: From less than 0.005 to 0.01-0.02 mm/year in stripe region
• Squeaking: Roughened wear stripe causes acoustic friction
• Not catastrophic: Gradual wear, may remain asymptomatic for years

Prevention: Optimal cup positioning (40° inclination, 15° anteversion, avoid greater than 50°)

In vivo aging of pure zirconia:

• Mechanism: Hydrothermal degradation in body fluids (moisture-assisted transformation)
• Tetragonal to monoclinic: Metastable t-ZrO2 transforms to stable m-ZrO2 over time
• Volume expansion: 3-5% expansion creates surface upheaval (roughening)
• Accelerated wear: Rough zirconia head abrades polyethylene liner (wear rate 0.1-0.3 mm/year)
• Timeline: Transformation detectable at 2-5 years, significant roughening at 5-10 years

Why BIOLOX Delta does not fail this way:

• Zirconia content only 17% (vs 100% in pure zirconia)
• Matrix constraint: Alumina matrix physically constrains zirconia platelets, prevents expansion
• No in vivo aging: BIOLOX Delta shows no phase transformation after 20+ years clinical use

Classification by Regulatory Status (IMPORTANT for Exam)

Preoperative Assessment for Ceramic Bearing Selection

Investigations to determine suitability for ceramic bearings:

Intraoperative Quality Inspection

Critical quality checks before implantation:

Inspect ceramic components for defects:

• Cracks or chips: Linear surface cracks, edge chips (reject if present)
• Color changes: Discoloration indicates manufacturing defect
• Surface irregularities: Scratches, pits, rough areas

If ANY defect visible, REJECT component (catastrophic fracture risk)

Sterile packaging:

• Check expiration date
• Ensure seal intact (no moisture ingress)
• If package compromised, DO NOT use (sterility and quality not guaranteed)

Traceability:

• Document lot numbers of femoral head and acetabular liner
• Rationale: If manufacturer recall occurs, allows identification of affected implants
• Enter into implant registry (Australian Orthopaedic Association National Joint Replacement Registry, AOANJRR)

Postoperative Radiographic Surveillance

Imaging protocol for ceramic bearings:

Radiographic signs of ceramic complications:

Investigation of Squeaking

Squeaking: Audible noise from ceramic-on-ceramic bearing (1-8% incidence):

Characterize squeaking:

• Timing: With specific movements (stairs, sitting-to-stand, getting out of car), constant, intermittent
• Loudness: Audible to patient only, or others in room
• Pain association: Squeaking alone (benign), or with pain (concern for impingement, edge loading)
• Functional impact: Patient embarrassment, activity limitation, or asymptomatic

Physical examination:

• Provocative maneuvers: Reproduce squeak with hip flexion-adduction-internal rotation (impingement position)
• Range of motion: Assess for impingement (flexion less than 90°, painful terminal flexion)

AP pelvis and lateral hip radiographs:

• Cup position: Measure inclination (normal 30-50°, steep if greater than 50°) and anteversion (normal 5-25°)
• Stripe wear: Linear radiolucency at liner equator (indicates edge loading)
• Impingement: Femoral neck-acetabular liner proximity, anterior or posterior impingement zones
• Component loosening: Radiolucent lines, migration (rare cause of squeaking)

CT scan (if radiographs inconclusive):

• More accurate cup version measurement (radiographic anteversion can be misleading)
• 3D impingement analysis

Most squeaking is benign and resolves spontaneously:

• Observation: If asymptomatic or mild, reassure patient, observe
• Activity modification: Avoid provocative movements if possible
• Revision rarely indicated: Only if severe functional impairment, pain, or progressive stripe wear

Revision considered if:

• Squeaking with pain (suggests impingement or edge loading)
• Cup malposition (greater than 50-55° inclination, excessive anteversion)
• Progressive stripe wear on serial radiographs
• Severe functional or psychological impact (patient-driven decision)

Retrieval Analysis (Research/Registry)

Analysis of retrieved ceramic components provides insights into wear and failure mechanisms:

Decision-Making Algorithm for Ceramic Bearing Selection

Systematic approach to choosing appropriate bearing surface:

Age less than 50-60 years, high activity:

• Recommendation: Ceramic-on-ceramic (CoC) FIRST CHOICE
• Rationale: Lowest wear rate (less than 0.005 mm/year), longest projected implant lifespan (30-40 years)
• Alternative: Ceramic-on-XLPE if patient not willing to accept squeaking risk (1-8%)

Age 60-75 years, moderate activity:

• Recommendation: Ceramic-on-XLPE OR ceramic-on-ceramic (shared decision-making)
• Rationale: Both provide acceptable longevity for this age group. CoXLPE avoids squeaking, CoC provides lowest wear.

Age greater than 75 years, low activity:

• Recommendation: Metal-on-XLPE or ceramic-on-XLPE (ceramic not necessary)
• Rationale: Projected lifespan 10-15 years, wear rate less critical, cost considerations favor metal-on-XLPE

Normal acetabular anatomy:

• Can achieve optimal cup position (40° inclination, 15° anteversion): Ceramic-on-ceramic suitable

Acetabular dysplasia (Crowe I-II):

• Mild dysplasia: Can usually achieve safe cup position with good coverage: Ceramic-on-ceramic suitable
• Severe dysplasia (Crowe III-IV): May require steep cup (greater than 50°), medialized socket, or structural graft: Consider ceramic-on-XLPE (lower fracture risk with steep cup)

High impingement risk (coxa vara, retroverted femur, short femoral neck):

• Consider ceramic-on-XLPE: Lower fracture risk if impingement occurs

Obesity (BMI greater than 35):

• Higher joint reaction forces increase ceramic fracture risk
• Recommendation: Ceramic-on-XLPE (lower fracture risk) OR metal-on-XLPE

Very high-impact sports (running, contact sports):

• Peak loads increase fracture risk
• Shared decision: Discuss risk-benefit of CoC (lowest wear, small fracture risk) vs CoXLPE (slightly higher wear, lower fracture risk)

Squeaking intolerance:

• Patient not willing to accept 1-8% squeaking risk: Ceramic-on-XLPE (no squeaking)

Metal sensitivity:

• History of metal allergy: Ceramic-on-ceramic or ceramic-on-XLPE (both avoid metal bearing surface)

Non-Operative Management (Rare)

Ceramic bearings are implant materials, not conditions requiring treatment. However, complications may be managed conservatively:

Management of Ceramic Fracture (Intraoperative and Postoperative)

Ceramic fracture is a surgical emergency requiring urgent revision:

If ceramic fracture occurs during implantation (head fracture during impaction, liner fracture during seating):

Immediate actions:

• STOP procedure, do not proceed with fractured component
• Copious irrigation: 9-12 liters normal saline to wash out ceramic particles
• Remove all visible fragments: Inspect joint capsule, muscles, soft tissues
• Change gloves, gowns, drapes: Prevent reintroduction of ceramic particles
• Replace ALL components: New ceramic head AND liner (even if only one fractured)
• Consider larger head size: Provides more clearance, reduces risk of repeat fracture

If extensive contamination:

• Abort ceramic bearing: Switch to metal-on-XLPE (ceramic debris present, cannot use ceramic-on-polyethylene)
• Document thoroughly: Operative note must detail fracture, irrigation, component changes

Patient presents with sudden onset pain, grinding, inability to weight bear after previous ceramic-on-ceramic THA:

Diagnosis confirmation:

• Radiographs: Look for radio-dense ceramic fragments, component separation, metallic debris cloud
• CT scan: Better visualization of fragment distribution
• Metal artifact reduction sequence (MARS) MRI: Assess soft tissue involvement, synovitis

Surgical planning:

• Revision within 2-4 weeks (urgent, not emergent unless severe pain/instability)
• Consent patient: Explain need for complete synovectomy, possible component retention vs exchange, risk of incomplete debris removal
• Implant planning: New ceramic-on-ceramic (preferred if acetabular component stable) OR constrained liner if instability

Systematic approach to ceramic fracture revision:

Step 1: Exposure and Synovectomy

• Extended approach: Consider extensile approach for complete access
• Complete synovectomy: Remove ALL synovium (ceramic particles embedded in synovium act as abrasive)
• Inspect surrounding tissues: Psoas, gluteus medius, capsule (may harbor fragments)

Step 2: Irrigation

• Copious pulsed lavage: 12-15 liters normal saline with pulsed lavage device
• Change irrigation tips frequently: Prevent reintroducing particles

Step 3: Component Assessment

• Femoral stem: If well-fixed and correctly positioned, retain stem, exchange head only
• Acetabular shell: If well-fixed, retain shell, exchange liner only
• If malpositioned: Revise to correct position (prevent recurrent edge loading fracture)

Step 4: New Bearing Selection

• FIRST CHOICE: New ceramic-on-ceramic (BIOLOX Delta head and liner)
• Rationale: Ceramic resists scratching from residual ceramic particles better than polyethylene
• Head size: Use same or larger size (larger head provides more clearance)
• ALTERNATIVE (if ceramic unavailable or patient preference): Dual mobility construct with metal head (resists third-body wear better than standard PE)

Step 5: Closure and Postoperative Management

• Closed suction drain: Remove particulate debris in early postoperative period (48 hours)
• Postoperative radiographs: Document component position, assess for residual fragments

Management Algorithm for Component Selection

Shared Decision-Making Framework

Important discussion points when offering ceramic bearings:

Framework for discussion:

1. Explain options: Ceramic-on-ceramic (lowest wear, small squeak risk), ceramic-on-XLPE (low wear, no squeak, lower fracture risk), metal-on-XLPE (standard, proven, lowest cost)
2. Elicit patient priorities: Longevity vs cost, willingness to accept squeak risk, activity level
3. Provide recommendation based on age, activity, anatomy, patient priorities
4. Shared decision: Patient makes final choice after understanding trade-offs

Key Principles for Ceramic Bearing Implantation

Ceramic bearings require meticulous technique to minimize fracture risk:

Acetabular Cup and Ceramic Liner Insertion

Reaming:

• Sequential reaming to appropriate size (typically 1-2mm under-reaming for press-fit cup)
• Hemisphere exposed: Aim for 40-45° inclination during reaming (guides final cup position)
• Medial wall intact: Avoid excessive medialization (decreases cup stability)

Trial cup position:

• Insert trial cup, assess inclination and anteversion with alignment guide
• Target: 40° inclination, 15° anteversion (Lewinnek safe zone 30-50°, 5-25°)
• Critical for ceramic: Avoid greater than 50° inclination (edge loading risk)

Impaction technique:

• Line-to-line or 1-2mm press-fit (adequate for cementless fixation)
• Use cup impactor aligned with desired cup position vector
• Controlled sequential blows to seat cup (avoid excessive force causing acetabular fracture)
• Assess seating: Cup should be flush with prepared acetabulum, no gaps

Supplemental fixation (if needed):

• Screw fixation: 1-2 screws in posterosuperior quadrant if poor bone quality or revision
• Safe zones for screws: Posterior column (avoid sciatic notch), ilium superior to dome

Inspect ceramic liner:

• Visual inspection: Check for cracks, chips, discoloration (reject if ANY defect visible)
• Keep clean: Ceramic liner must remain dry and clean (no blood, saline, cement)

Seating the liner:

• Taper alignment: Ceramic liner has metal backing with Morse taper that locks into metal shell
• Align orientation: Some liners have anti-rotation features or locking mechanism, ensure correct orientation
• Gentle hand pressure FIRST: Press liner into shell with hand pressure, should seat partially
• Impaction with liner impactor: Use manufacturer-provided plastic or soft metal impactor
  • CRITICAL: NEVER use metal instrument directly on ceramic surface
  • Controlled gentle blows: Gradual impaction until liner fully seated (hear/feel change in pitch when seated)
  • Avoid excessive force: Liner should seat with 3-5 gentle taps, NOT forceful strikes

Verify seating:

• Visual inspection: Liner should be flush with metal shell, no gaps
• Palpate rim: Run finger around liner edge, should be smooth transition from liner to metal shell
• Stability: Gentle attempt to displace liner (should be rock-solid, no movement)

Femoral Stem and Ceramic Head Insertion

Femoral preparation:

• Sequential broaching to appropriate stem size
• Anteversion target: 10-15° (combined anteversion 25-30° when added to cup)
• Version assessment: Use trial stem with alignment guide to confirm version

Stem insertion:

• Standard cementless or cemented technique depending on bone quality and stem design
• Achieve stable fixation: Axial and rotational stability critical

Inspect ceramic head:

• Visual inspection: Check for cracks, chips, surface irregularities (reject if ANY defect)
• Keep clean and DRY: Ceramic head bore must be completely dry (NO saline, blood, or fluid)
  • Wet taper reduces friction: Can cause head to slide down taper excessively during impaction, creating radial cracks

Prepare femoral taper:

• Dry and clean: Wipe taper with dry sponge (NO saline)
• Remove debris: Any metal debris, cement, or bone fragments will prevent proper seating

Impaction technique:

• Align head: Place ceramic head onto taper, ensure correct orientation (if head has offset or grooves)
• Gentle controlled impaction: Use manufacturer-provided plastic head impactor
  • CRITICAL: NEVER strike ceramic head directly with metal mallet
  • Gradual seating: 2-4 gentle taps, increase force gradually
  • Listen for pitch change: Fully seated head produces higher-pitch sound when struck (vs dull thud when unseated)
  • Avoid excessive force: Head should seat with 3-5 controlled blows, NOT forceful strikes

Verify seating:

• Pull test: Gentle attempt to remove head (should not budge)
• Rotation test: Attempt to rotate head on taper (should be completely stable, no rotation)
• Visual assessment: Gap between head base and neck shoulder should be minimal (typically less than 1mm)

Head size selection:

• Larger heads: Greater range of motion, lower dislocation risk, BUT higher edge loading forces
• Recommended sizes: 32mm, 36mm (28mm smaller heads higher dislocation risk, 40mm+ higher edge loading risk)
• Match liner: Head diameter must match ceramic liner inner diameter exactly

Trial Reduction and Component Check

Before impacting ceramic head on real stem:

• Use trial components: Trial femoral head (metal) on real stem, trial liner in real cup
• Assess stability: Range of motion, impingement-free arc, leg length, offset
• Check cup position: Confirm inclination less than 50°, anteversion appropriate
• If unstable or poor position: Modify components or cup position BEFORE using ceramic

Only proceed with ceramic after confirming satisfactory trial:

• Stable hip, adequate range of motion, no impingement, cup position optimal

Reduce ceramic bearing:

• Gentle reduction: Support femoral head, guide into acetabular liner (NO forceful clunking)
• Confirm reduction: Hip should move smoothly through full range of motion
• Assess stability: Provocative maneuvers (flexion-adduction-internal rotation, extension-adduction-external rotation)

Protect bearing during closure:

• Avoid dislocation: Maintain hip in neutral position during closure
• No excessive motion: Avoid extreme positions that could cause dislocation during closure
• Suction drain placement: Place drain away from hip joint (avoid proximity to ceramic bearing)

Advanced Technique Considerations

Optimal Cup Positioning Strategy for Ceramic Bearings

Achieving 40° inclination, 15° anteversion (minimize edge loading):

Mechanical alignment guides:

• Cup impactor with alignment guides: Rod or laser guide showing cup orientation relative to patient anatomy
• Align to anatomic landmarks: Transverse acetabular ligament (TAL) approximates anatomic acetabular version (NOT true version)
• Radiographic method: Intraoperative fluoroscopy (AP pelvis) measures inclination directly

Target position:

• Inclination: 40° relative to horizontal (defined by ischial tuberosities or floor)
• Anteversion: 15° relative to coronal plane
• Acceptable range: Lewinnek safe zone (30-50° inclination, 5-25° anteversion)
• AVOID: Greater than 50° inclination (edge loading), greater than 25° anteversion (posterior impingement)

Advantages for ceramic bearings:

• Precise cup positioning: Achieve target 40° inclination, 15° anteversion with ±2-3° accuracy (vs ±5-10° freehand)
• Real-time feedback: Adjust cup position before final impaction
• Reduced outliers: Fewer cups outside Lewinnek safe zone (outlier rate 5-10% with navigation vs 20-30% freehand)

Disadvantages:

• Cost: Navigation systems expensive, may increase operative time
• Learning curve: Requires surgeon training and experience
• Registration errors: Pelvic registration errors can propagate to cup position errors

Recommendation: Consider navigation/robotics for complex cases (dysplasia, revision) or surgeons early in learning curve.

Pelvic tilt affects functional cup orientation:

• Supine radiographs: Show anatomic position (patient lying flat)
• Standing radiographs: Show functional position (pelvic tilt affects cup orientation)
• Pelvic retroversion (posterior tilt in stance): Functional cup more vertical (higher inclination) than anatomic

Adjust for pelvic tilt (advanced):

• Measure pelvic incidence minus lumbar lordosis (PI-LL)
• If PI-LL greater than 10° (flat back, posterior pelvic tilt): Aim for anatomic inclination 35-38° (will be 40-45° functional)
• If PI-LL less than -10° (hyperlordotic, anterior pelvic tilt): Aim for anatomic inclination 42-45° (will be 38-42° functional)

Managing Intraoperative Ceramic Fracture

If ceramic fracture occurs during insertion:

Overview of Ceramic Bearing Complications

Ceramic Fracture

Squeaking

Stripe Wear

Definition: Visible wear stripe on ceramic head from edge loading against the acetabular liner rim.

Causes:

• Acetabular cup malposition (excessive inclination greater than 50°)
• Microseparation during swing phase
• Impingement causing subluxation

Consequences:

• Surface roughening accelerates wear
• May cause or exacerbate squeaking
• Rarely causes fracture but indicates edge loading

Prevention: Optimal cup positioning, larger heads (36mm vs 28mm), avoiding impingement

Dislocation Considerations

Trunnionosis (Specific to Larger Ceramic Heads)

Mechanism: Larger ceramic heads generate more torque at the femoral head-taper junction, accelerating mechanically-assisted crevice corrosion.

Risk factors:

• Large head size (40mm+)
• Long neck lengths (increased moment arm)
• Ti-6Al-4V taper (vs CoCr - more susceptible)
• High activity level

Presentation:

• Pain, often groin or thigh
• Elevated serum cobalt and chromium (from taper)
• Pseudotumor formation (rare)
• Taper wear visible on revision

Prevention:

• Optimal head size (36mm rather than 40mm when possible)
• Short/neutral neck lengths when biomechanically appropriate
• Ti-sleeve adapters available for some designs

Ceramic Fracture: Detailed Pathophysiology

Head Fracture Mechanism:

Sequence of events:

1. Taper contaminated with saline/blood during impaction
2. Ceramic head slides excessively down taper (reduced friction)
3. Radial tensile stress generated in ceramic head bore
4. Microscopic radial cracks initiate at bore surface
5. Cyclic loading propagates cracks over days to months
6. Catastrophic fracture when critical crack length reached

Time to fracture: Days to years (typically within first 2 years)

Sequence of events:

1. Cup positioned with excessive inclination (greater than 50°)
2. Femoral head loads onto liner rim rather than center during stance
3. Concentrated rim stress exceeds ceramic fracture threshold
4. Crack initiates at rim, propagates into liner body
5. Catastrophic failure with fragmentation into joint

Risk amplifiers: Component mismatch, impingement, trauma

Management of Squeaking - Detailed Algorithm

Revision After Ceramic Fracture: Technical Considerations

Comparison: Ceramic vs XLPE Complication Profiles

Long-Term Surveillance for Ceramic Complications

Recommended follow-up schedule:

Postoperative Protocol for Ceramic-on-Ceramic THA

Hip Precautions

Note: Ceramic bearings allow larger head sizes (36mm, 40mm), which may reduce dislocation risk and potentially allow relaxed precautions, but this depends on surgeon preference and approach.

Weight-Bearing Protocol

Ceramic-specific: No modification to weight-bearing based on bearing surface.

Activity Recommendations

Patient Counseling: Squeaking

Follow-Up Schedule

Enhanced Recovery After Surgery (ERAS) Protocol for Ceramic THA

Standard ERAS elements:

• Preoperative education and expectation setting (include squeaking discussion)
• Optimization of comorbidities (diabetes, anemia, nutrition)
• Smoking cessation (6+ weeks preoperatively)
• Carbohydrate loading (clear liquids with carbohydrate up to 2 hours preop)
• Minimal fasting (6 hours solids, 2 hours clear fluids)

Anesthetic and surgical factors:

• Spinal anesthesia preferred (reduced blood loss, PONV, respiratory complications)
• Multimodal analgesia (local infiltration analgesia, periarticular injection)
• Tranexamic acid (reduce blood loss)
• Normothermia maintenance
• Fluid optimization (goal-directed fluid therapy)
• Ceramic-specific: Meticulous component insertion technique (dry taper, gentle impaction)

Day 0:

• Oral intake 2-4 hours postop
• Mobilization day 0 if tolerated
• Urinary catheter removal early (if used)
• Multimodal oral analgesia (minimize opioids)

Day 1-2:

• Progressive mobilization (stairs by day 1-2)
• Discharge when functional criteria met
• Same-day discharge for selected patients

Target LOS: 1-3 days (vs historical 5-7 days)

Rehabilitation Protocol

DVT Prophylaxis

Standard protocol (no ceramic-specific modification):

Note: Aspirin 100mg BD increasingly accepted for standard-risk patients (equivalent VTE prevention, lower bleeding risk).

Managing Early Complications

Return to Driving

Evidence-based recommendations:

Criteria: Off opioid analgesia, brake reaction time under 700ms, no hip precaution violation while driving.

Return to Work

Long-Term Activity and Ceramic Longevity

Ceramic advantage: Ultra-low wear means activity level has less impact on bearing longevity compared to polyethylene. Main concerns are dislocation and fracture (mechanical), not wear.

Overall Survivorship

Revision Rates by Bearing

Functional Outcomes

Patient-reported outcome measures (PROMs):

Key finding: Functional outcomes are equivalent between bearing surfaces at short-to-medium term follow-up.

Wear Performance

Ceramic advantage: 10-fold lower wear translates to negligible osteolysis risk, important for younger patients with longer life expectancy.

Ceramic-Specific Outcomes

Registry Data: Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR)

Ceramic-on-Ceramic Outcomes (AOANJRR 2022 Report):

Age-specific outcomes:

• Under 55 years: Ceramic-on-ceramic shows slight advantage (4.8% vs 5.4% for metal-on-XLPE)
• 55-64 years: Equivalent outcomes
• Over 65 years: Metal-on-XLPE slightly favored (patient selection bias)

International Registry Comparisons

Long-Term Survivorship: 15-20 Years

Published studies (single-center, prospective):

Trend: BIOLOX Delta shows improved outcomes compared to earlier alumina (lower fracture, similar squeaking).

Factors Affecting Ceramic Outcomes

Cost-Effectiveness Analysis

Cost-effectiveness: Ceramic-on-ceramic cost-effective in patients with greater than 20-year life expectancy where lower revision rate offsets higher implant cost.

Comparison: Ceramic-on-Ceramic vs Ceramic-on-XLPE

Ceramic-on-XLPE: Combines low wear of ceramic articulation with toughness of polyethylene. Eliminates liner fracture and squeaking risk. Increasingly popular alternative.

Outcomes by Head Size

36mm head: Optimal compromise between dislocation prevention and trunnionosis/squeaking risk.