High Yield Overview

CERAMIC-ON-CERAMIC THA

Hard-on-hard bearing | Arthroplasty

Mnemonic

DELTA

Mnemonic

CLEAN

Critical Danger Structures

Ceramic Liner Integrity

Within acetabular shell. Location: Liner-shell interface with locking mechanism. Protection: DRY, CLEAN shell; PLASTIC impactor only; SINGLE impaction; 360° inspection for complete seating; never use metal directly on ceramic.

Ceramic Head Integrity

On femoral stem trunnion. Location: Head-taper (Morse taper) junction. Protection: DRY trunnion (wipe with sterile gauze); SINGLE firm impaction only; never tap multiple times (microcracks); use plastic or dedicated ceramic head impactor.

Morse Taper Surface

Femoral stem trunnion. Location: Junction between femoral component and head. Protection: Inspect for scratches or damage; keep absolutely DRY; any taper damage causes fretting corrosion and head dissociation risk.

Sciatic Nerve

Posterior to hip joint. Location: 1-2cm behind posterior acetabular rim, courses over short external rotators. Protection: Avoid over-retraction posteriorly; protect during capsulotomy; knee flexion reduces tension.

Femoral Neurovascular Bundle

Anterior to hip joint. Location: Femoral nerve, artery, vein in femoral triangle. Protection: Careful anterior retractor placement; avoid excessive anterior acetabular reaming; protect with anterior labrum if using DAA.

Ceramic Evolution and Composition

Property	BIOLOX Delta (4th Gen)	Pure Alumina (3rd Gen)
Composition	Alumina matrix + zirconia platelets + chromium oxide	99.9% pure alumina (Al₂O₃)
Fracture Rate	0.02-0.05%	0.1-0.2%
Fracture Toughness	6.5 MPa√m	4.0 MPa√m
Mechanism	Transformation toughening from zirconia	Brittle fracture
Grain Size	Submicron (0.5μm)	Larger grains
Head Sizes	28mm, 32mm, 36mm available	Limited sizes

Key Mechanism: Zirconia platelets undergo phase transformation (tetragonal → monoclinic) when stressed, absorbing energy and stopping crack propagation

Positioning and Preparation

Patient Position: Per surgical approach preference

Lateral decubitus for posterior approach
Supine for direct anterior approach
Lateral for anterolateral approach

Surgical Approach: Surgeon-preferred approach - ceramic bearing compatible with all standard approaches

Key Preparation Points:

Confirm ceramic inventory availability (specific sizes)
Verify backup bearing option available
Preoperative templating for component sizing
Patient counseling about squeaking complete

Operative Technique

Step 1: BEARING SURFACE SELECTION

BEARING SURFACE SELECTION: CERAMIC-ON-CERAMIC (CoC) indicated for young active patients where wear and longevity are priorities. Modern 4th generation ceramics (BIOLOX delta = alumina matrix composite with zirconia and chromium oxide) have superior fracture resistance. Lowest wear rates of all bearing couples (<0.01mm/year linear wear). Confirm appropriate patient selection criteria met.

Exam Pearl

Technical Tip: EXAM KEY: BIOLOX DELTA is alumina matrix composite - NOT pure alumina. Contains zirconia platelets for transformation toughening. LOWEST WEAR of all bearings. Indicated in YOUNG, ACTIVE patients with good bone quality.

Dangers at this step

Wrong bearing selection for patient profile (age, activity, expectations)
Using older generation pure alumina ceramics (higher fracture risk)
Inadequate patient counseling about squeaking possibility

Step 2: CONTRAINDICATION ASSESSMENT

CONTRAINDICATIONS AND RISKS: Absolute: known ceramic fracture history (any joint). Relative: severe hip dysplasia (cup position difficult), high BMI (component stress), patient anxiety about squeaking. SQUEAKING occurs in 1-10% - usually benign but distressing. FRACTURE risk reduced with modern ceramics but still exists (0.02-0.05% with BIOLOX delta).

Exam Pearl

Technical Tip: EXAM KEY: SQUEAKING is NOT failure - occurs 1-10%, multifactorial (edge loading, cup position, stripe wear). Reassure patients. FRACTURE rate now <0.05% with 4th gen ceramics. Previous ceramic fracture = ABSOLUTE contraindication.

Dangers at this step

Proceeding with contraindicated patient (prior ceramic fracture)
Inadequate preoperative discussion about complications
Not having backup bearing option available

Step 3: SURGICAL APPROACH AND EXPOSURE

SURGICAL APPROACH: Execute preferred approach (posterior, DAA, anterolateral). Excellent exposure essential for accurate cup positioning. CoC requires optimal visualization for precise component placement given less forgiving nature of hard-on-hard bearing.

Exam Pearl

Technical Tip: Approach selection does not affect ceramic bearing outcomes. What matters is achieving OPTIMAL CUP POSITION. Poor exposure → poor position → edge loading → squeaking/wear/failure.

Dangers at this step

Inadequate exposure compromising cup positioning accuracy
Excessive soft tissue retraction causing nerve injury
Capsule damage affecting stability

Step 4: ACETABULAR PREPARATION

ACETABULAR PREPARATION: Standard sequential reaming technique. Remove all soft tissue from acetabular floor. Ream to bleeding subchondral bone. Critical to achieve optimal cup orientation - CoC is LESS FORGIVING of malposition than polyethylene. Target LEWINNEK SAFE ZONE: 40° ± 10° inclination, 15° ± 10° anteversion. For CoC, aim for narrower range: 35-45° inclination.

Exam Pearl

Technical Tip: EXAM KEY: CoC LESS FORGIVING of cup malposition than metal-on-poly. Edge loading causes stripe wear and squeaking. STEEP CUPS (more than 55°) associated with higher failure. Target tighter tolerances than Lewinnek for hard-on-hard bearings.

Dangers at this step

Cup malposition outside target range (will cause edge loading)
Over-reaming compromising press-fit
Anterior column perforation with aggressive reaming

Step 5: SHELL INSERTION AND POSITIONING

SHELL INSERTION AND FIXATION: Standard press-fit technique with 1-2mm under-ream. Shell must be RIGIDLY FIXED before ceramic liner insertion. Any micromotion can cause liner dissociation. Supplemental screw fixation if any question of primary stability. Use alignment guides or navigation if available.

Exam Pearl

Technical Tip: EXAM KEY: RIGID SHELL FIXATION mandatory before ceramic liner insertion. Micromotion → liner dissociation risk. Use supplemental screws if ANY doubt about fixation quality. Position first, fixation second with CoC.

Dangers at this step

Inadequate shell press-fit (leading to micromotion)
Malposition locked in before recognizing error
Over-impaction causing acetabular fracture

Step 6: SHELL POSITION VERIFICATION

SHELL POSITION VERIFICATION: Before liner insertion, confirm cup position within target range. Use intraoperative radiography if available. Assess inclination and anteversion. If outside optimal range for CoC, consider alternative bearing (polyethylene more forgiving). This is last chance to change bearing choice.

Exam Pearl

Technical Tip: Once ceramic liner is impacted, bearing choice is committed. If cup position suboptimal (more than 50° inclination), strongly consider polyethylene liner instead. INTRAOPERATIVE DECISION POINT.

Dangers at this step

Proceeding with ceramic liner despite suboptimal cup position
Missing opportunity to convert to polyethylene
Inadequate position assessment before commitment

Step 7: SHELL PREPARATION FOR LINER

SHELL PREPARATION FOR LINER: Shell must be absolutely DRY and FREE OF DEBRIS before ceramic liner insertion. Any particle (bone, blood, cement, debris) can chip ceramic during impaction. Use sterile gauze to dry shell completely. Inspect for any loose material. No saline rinse (leave wet surface).

Exam Pearl

Technical Tip: EXAM KEY: DRY, CLEAN shell is MANDATORY. Any debris causes ceramic chipping → third-body wear → accelerated failure. Wipe with DRY sterile gauze, not saline. Inspect 360° before liner insertion.

Dangers at this step

Debris in shell causing ceramic chip during impaction
Wet shell surface interfering with liner seating
Blood/soft tissue in shell-liner interface

Step 8: CERAMIC LINER INSERTION - CRITICAL STEP

CERAMIC LINER INSERTION: Check liner orientation for locking mechanism alignment with shell. Use PLASTIC IMPACTOR (never metal directly on ceramic). Position liner in shell with correct orientation. Apply STEADY FIRM PRESSURE - listen for click confirming seating. SINGLE IMPACTION only - repeated impaction can chip liner. No adjustments once impacted.

Exam Pearl

Technical Tip: EXAM KEY: PLASTIC IMPACTOR only on ceramic. SINGLE IMPACTION with firm steady pressure. Never hammer directly on ceramic with metal. Multiple impaction attempts create microcracks and chips.

Dangers at this step

Using metal impactor directly on ceramic liner
Multiple impaction attempts causing chips/cracks
Incorrect liner orientation (locking mechanism misaligned)
Incomplete seating from inadequate impaction force

Step 9: LINER SEATING VERIFICATION

VERIFY LINER SEATING: After insertion, INSPECT 360° for complete seating. Run finger around liner-shell junction - any gap indicates incomplete seating. Check locking mechanism engaged (audible click, visual confirmation). Confirm no chips or cracks visible on liner face or edge. Any concern → remove and re-assess.

Exam Pearl

Technical Tip: EXAM KEY: 360° INSPECTION for complete seating is MANDATORY. Any visible gap = incomplete seating = dissociation risk. Check locking mechanism ENGAGED. Undetected incomplete seating → early failure.

Dangers at this step

Missing incomplete liner seating (will dissociate)
Undetected chip or crack (will propagate)
Locking mechanism not engaged (liner will rotate/dissociate)

Step 10: FEMORAL PREPARATION

FEMORAL PREPARATION: Standard technique for chosen stem (cementless or cemented). Sequential broaching to appropriate size. Prepare for trial reduction. Ceramic head sizing per templating - confirm available inventory.

Exam Pearl

Technical Tip: Femoral preparation is standard technique. The critical ceramic-specific steps are in head placement. Ensure trunnion (Morse taper) remains undamaged during broaching and trialing.

Dangers at this step

Damaging femoral stem trunnion during preparation
Inadequate femoral stem fixation
Femoral fracture from aggressive broaching

Step 11: TRIAL REDUCTION

TRIAL REDUCTION: Insert trial head on stem trunnion. Reduce hip and assess stability, leg length, offset. Standard testing in flexion, extension, rotation. AVOID extreme positions that cause edge loading during trials. Confirm appropriate head size and neck length.

Exam Pearl

Technical Tip: Trial reduction with trial head is standard. This assesses stability and leg length before committing to ceramic head. Avoid excessive testing in positions that stress ceramic edge (combined flexion/IR/adduction).

Dangers at this step

Trunnion damage from trial head placement/removal
Missing instability before final head placement
Edge loading positions during aggressive stability testing

Step 12: TRUNNION PREPARATION FOR CERAMIC HEAD

TRUNNION PREPARATION: After removing trial head, inspect trunnion (Morse taper) carefully. Must be PRISTINE - any scratches or damage cause fretting corrosion and head dissociation risk. Taper must be absolutely DRY - wipe with sterile dry gauze. No saline. No blood. Completely dry surface essential for ceramic head seating.

Exam Pearl

Technical Tip: EXAM KEY: MORSE TAPER must be CLEAN, DRY, UNDAMAGED. Any scratches cause fretting corrosion → head dissociation. Inspect trunnion under direct vision. Wipe dry with sterile gauze - no wet surfaces.

Dangers at this step

Damaged trunnion causing fretting corrosion and dissociation
Wet taper causing poor ceramic head seating
Blood/debris on taper interface

Step 13: CERAMIC HEAD IMPACTION

CERAMIC HEAD IMPACTION: Place ceramic head on dry trunnion. Confirm correct orientation. Single FIRM impaction using plastic or dedicated ceramic head impactor. Do NOT tap head multiple times - can create microcracks that propagate to fracture. Head should seat with audible click. Never use metal directly on ceramic head.

Exam Pearl

Technical Tip: EXAM KEY: DRY TAPER. SINGLE FIRM IMPACTION. Multiple taps create microcracks → delayed fracture. Never use metal mallet directly on ceramic. Audible click confirms seating.

Dangers at this step

Wet taper causing poor seating → dissociation
Multiple impactions creating microcracks → fracture
Metal impactor damaging ceramic head
Incomplete seating from inadequate impaction force

Step 14: REDUCTION AND STABILITY TESTING

REDUCTION AND STABILITY: Reduce hip. Standard stability testing in flexion, extension, internal/external rotation, adduction. AVOID EDGE LOADING positions during testing - extreme flexion with internal rotation and adduction stresses ceramic edge. Document ROM achieved. Confirm stable reduction in functional positions.

Exam Pearl

Technical Tip: EXAM KEY: Avoid extreme positions that cause EDGE LOADING during stability testing. Combined flexion/IR/adduction stresses ceramic bearing edge. Test stability but respect ceramic limitations.

Dangers at this step

Edge loading causing ceramic damage during testing
Dislocation during aggressive stability testing
Missing subtle instability before closure

Step 15: CLOSURE AND POST-OPERATIVE CONSIDERATIONS

CLOSURE AND POST-OPERATIVE CARE: Standard layered closure. Standard THA rehabilitation protocol. No specific activity restrictions beyond standard hip precautions. Counsel patient about SQUEAKING - occurs 1-10%, usually benign. Most squeaking improves over time. Long-term surveillance with standard follow-up schedule.

Exam Pearl

Technical Tip: EXAM KEY: COUNSEL about squeaking preoperatively - sets expectations. Squeaking is NOT indication for revision unless symptomatic impingement proven. Excellent long-term wear rates justify ceramic bearing in appropriate patients.

Dangers at this step

Inadequate patient education about squeaking
Patient anxiety leading to unnecessary revision request
Missing postoperative complications (infection, dislocation)

Complications

Ceramic-on-Ceramic THA Complications

Post-operative Care

Immediate Post-operative:

Standard THA recovery protocol
Weight bearing as tolerated (unless bone quality concerns)
VTE prophylaxis per institutional protocol
Standard hip precautions per surgical approach

Rehabilitation:

No specific restrictions beyond standard THA precautions
Progressive ROM and strengthening
Gait training with appropriate assistive device
Standard return to activity timeline

Follow-up:

2 weeks: Wound check
6 weeks: Clinical and radiographic review
3 months: Function assessment
1 year: Standard annual review
Annual or biennial long-term surveillance

Patient Education:

Squeaking may occur (1-10%) - NOT failure
Report acute onset pain or clicking (may indicate fracture)
Excellent long-term wear expected
Standard activity guidelines

Exam Viva Scenarios

Practice these scenarios to excel in your viva examination

VIVA SCENARIOStandard

EXAMINER

"A 48-year-old active male construction worker presents for primary THA for end-stage osteoarthritis. He is otherwise healthy with BMI 26. He specifically asks about ceramic bearings. What are your considerations for bearing selection?"

EXCEPTIONAL ANSWER

This is an excellent candidate for ceramic-on-ceramic bearing given his age (less than 55), high activity level, and life expectancy of 30+ years where wear and longevity are priorities. I would discuss BIOLOX delta - a 4th generation alumina matrix composite with zirconia platelets providing enhanced fracture toughness (rates now 0.02-0.05%). CoC offers the lowest wear rates of all bearing couples at less than 0.01mm/year. However, I must counsel him about squeaking (1-10%), the less forgiving nature requiring optimal cup positioning, and ensure he has no prior ceramic fracture history. Given his occupation involving high activity, the excellent long-term wear profile makes CoC an appropriate choice. I would confirm adequate bone quality for uncemented fixation and have a polyethylene backup available intraoperatively.

VIVA SCENARIOStandard

EXAMINER

"You are performing a ceramic-on-ceramic THA. Describe your technique for ceramic liner insertion and the critical technical points."

EXCEPTIONAL ANSWER

Ceramic liner insertion is a CRITICAL step with no margin for error. First, the shell must be absolutely DRY and FREE OF DEBRIS - I wipe with sterile dry gauze (not saline) and inspect 360 degrees for any particles. Any debris can chip the ceramic during impaction causing third-body wear. Second, I confirm liner orientation with locking mechanism alignment to the shell. Third, I use a PLASTIC impactor only - never metal directly on ceramic. Fourth, I apply STEADY FIRM PRESSURE as a SINGLE IMPACTION - multiple taps can create microcracks that propagate to fracture. I listen for the audible click confirming seating. After insertion, I perform 360-degree inspection running my finger around the liner-shell junction to confirm complete seating with no gaps. I verify the locking mechanism is engaged and inspect the liner surface for any chips or cracks. Any incomplete seating requires removal and re-assessment.

VIVA SCENARIOStandard

EXAMINER

"A 52-year-old woman with previous ceramic-on-ceramic THA presents with sudden onset hip pain after hearing a 'crack' while getting up from a chair. X-rays suggest ceramic head fragmentation. How do you manage this?"

EXCEPTIONAL ANSWER

This is a catastrophic ceramic fracture requiring urgent revision surgery. My management principles are: First, confirm diagnosis with CT scan for better fragment assessment - not arthroscopy as fragments will be everywhere. Second, plan thorough revision surgery including: complete synovectomy to remove ALL ceramic fragments as even microscopic particles cause third-body wear; extensive pulse lavage with minimum 6 liters; inspect all components for damage. Third, and critically, I will NEVER use ceramic-on-ceramic again in this patient. Even after thorough debridement, microscopic ceramic fragments will remain in soft tissues and destroy any new ceramic bearing. I revise to a metal head on highly cross-linked polyethylene. Fourth, if there is bone loss or instability concerns, I may need constrained liner or augments. I counsel the patient about higher complication rates with revision and the bearing change rationale. Long-term surveillance for residual fragment-related wear is essential.