Back to Operative Surgery
Adult Reconstruction

Revision Total Hip Replacement - Acetabular Component

Comprehensive surgical technique guide for acetabular component revision in total hip replacement covering infection workup, Paprosky classification, bone loss reconstruction strategies, and instability management - FRCS exam preparation

Core Procedure
advanced
By OrthoVellum Medical Education Team

Reviewed by OrthoVellum Editorial Team

Editorial maintenance, source checking, and correction workflow • Published by OrthoVellum Medical Education Team

Editorial boardMethodologyReview policyReport a correction
High Yield Overview

REVISION TOTAL HIP REPLACEMENT - ACETABULAR COMPONENT

Complex reconstructive procedure for failed acetabular components with classification-driven approach to bone loss management | advanced

Critical Danger Structures

Sciatic Nerve

Location: Exits pelvis through greater sciatic notch below piriformis, 2cm posterior to short external rotators, may be scarred or displaced in revision

Protection: Early identification with vessel loop, gentle retraction, avoid excessive traction during exposure, palsy risk 2-5% in revision vs 0.5-1% primary

Superior Gluteal Neurovascular Bundle

Location: Exits pelvis above piriformis through greater sciatic notch, enters deep surface of gluteus medius and minimus muscles

Protection: Limit proximal dissection to less than 5cm above greater trochanter tip, stay subperiosteal when separating abductors from ilium for rim exposure

External Iliac Vessels

Location: Intrapelvic along pelvic brim anteriorly, 2-3cm anterior to acetabular rim at 2-4 o'clock position (right hip)

Protection: Avoid anteroinferior acetabular screws (vascular danger zone), keep screws posterosuperior quadrant only, prevent medial wall perforation during reaming

Obturator Neurovascular Bundle

Location: Exits pelvis through obturator foramen medially and inferiorly, runs along medial wall of acetabulum

Protection: Avoid medial wall perforation, careful reaming technique near floor, recognize anatomic landmarks (teardrop, transverse ligament)

Femoral Vessels and Nerve

Location: Anterior to hip capsule in femoral triangle, femoral nerve lateral, artery central, vein medial

Protection: Stay posterior with approach, avoid anterior dissection, recognize during anterior column fracture or intrapelvic cement extrusion

Mnemonic

I See More Terrible BonePAPROSKY Acetabular Classification

Mnemonic

SCREWSSCREWS Acetabular Fixation Principles

Indications for Acetabular Revision

Absolute Indications

Aseptic Loosening (Most Common 40-50%)

  • Progressive pain with weight bearing
  • Radiographic lucencies greater than 2mm in all 3 DeLee-Charnley zones
  • Component migration greater than 3mm vertical or 5mm horizontal on serial radiographs
  • Acetabular cup tilt or change in position compared to post-operative baseline

Polyethylene Wear with Osteolysis

  • Polyethylene wear rate exceeding 0.2mm per year (critical threshold)
  • Progressive osteolysis despite well-fixed shell (retained shell, liner exchange insufficient if osteolysis progressing)
  • Impending structural failure with large cavitary lesions

Recurrent Instability

  • Multiple dislocations (typically 3 or more) despite closed reduction and conservative management
  • Requires acetabular revision to correct malposition (excessive anteversion or inclination)
  • Often combined with constrained or dual mobility liner

Infection

  • Chronic periprosthetic joint infection requiring 2-stage revision (explantation, spacer, then reimplantation)
  • Acetabular component involvement demonstrated by positive cultures and imaging

Component Malposition

  • Symptomatic malposition causing instability, impingement, or accelerated wear
  • Outside Lewinnek safe zone (inclination 30-50°, anteversion 5-25°)
  • High hip center with progressive superior migration and abductor insufficiency

Relative Indications

  • Liner dissociation or locking mechanism failure (may be managed with liner exchange if shell stable)
  • Adverse reaction to metal debris (ARMD) from metal-on-metal bearings requiring revision to non-metal bearing
  • Pelvic discontinuity with acetabular instability
  • Severe metallosis requiring debridement and component revision

Mandatory Pre-operative Infection Workup

Serological Testing

ESR (Erythrocyte Sedimentation Rate)

  • Threshold: Greater than 30 mm/hr suspicious for infection
  • Sensitivity 82%, specificity 85%
  • Can be elevated by inflammatory conditions, malignancy, renal disease

CRP (C-Reactive Protein)

  • Threshold: Greater than 10 mg/L suspicious for infection
  • More specific than ESR, normalizes faster post-operatively
  • Sensitivity 96%, specificity 92%
  • Combined ESR and CRP improves diagnostic accuracy

Joint Aspiration (Gold Standard)

Indications for Aspiration

  • Any elevation in ESR or CRP
  • Clinical suspicion (pain, wound drainage, fever)
  • Should be performed OFF antibiotics for minimum 2 weeks (6 weeks preferred)

Aspiration Technique

  • Fluoroscopic or ultrasound guidance preferred
  • Lateral approach (anterior to greater trochanter) avoiding neurovascular structures
  • Send for: cell count with differential, aerobic and anaerobic cultures (hold 14 days), Gram stain

Interpretation

  • WBC greater than 3,000 cells/μL suspicious (sensitivity 84%, specificity 88%)
  • WBC greater than 10,000 cells/μL highly suspicious for infection
  • PMN percentage greater than 80% concerning for infection (sensitivity 84%, specificity 82%)
  • Culture positive = definite infection (but false negatives occur with biofilm, prior antibiotics)

Adjunctive Tests for Equivocal Cases

Alpha-Defensin

  • Synovial biomarker highly specific for infection
  • Sensitivity 97%, specificity 96%
  • Not affected by prior antibiotics
  • Expensive but excellent when ESR/CRP/cell count equivocal

Synovial CRP and IL-6

  • Synovial fluid inflammatory markers
  • CRP greater than 6.9 mg/L = infection
  • IL-6 greater than 9,000 pg/mL = infection
  • High sensitivity and specificity

ESR/CRP Alone Misses 30% of Infections - aspiration is mandatory in revision

Comprehensive Complications Table

Acetabular Revision Complications - Recognition, Prevention, and Management

Exam Viva Scenarios

Practice these scenarios to excel in your viva examination

VIVA SCENARIOStandard

EXAMINER

"A 72-year-old woman presents 8 years after primary total hip replacement with progressive pain and radiographic loosening of the acetabular component. Walk me through your approach to ruling out infection before proceeding with revision."

EXCEPTIONAL ANSWER
Infection workup is MANDATORY before any acetabular revision because missing infection leads to catastrophic outcomes. I obtain ESR and CRP first - ESR greater than 30 mm/hr or CRP greater than 10 mg/L are suspicious. However, ESR and CRP alone miss 30% of infections, so if either is elevated or I have any clinical concern (pain, wound issues, constitutional symptoms), I perform joint aspiration OFF antibiotics for minimum 2 weeks, preferably 6 weeks. I use fluoroscopic or ultrasound guidance for aspiration via lateral approach avoiding neurovascular structures. Aspirate is sent for cell count with differential - WBC greater than 3,000 suspicious, greater than 10,000 highly suspicious; PMN greater than 80% concerning for infection - and aerobic and anaerobic cultures held for 14 days, plus Gram stain. If results are equivocal, I add alpha-defensin which has 97% sensitivity and 96% specificity, or synovial CRP greater than 6.9 mg/L or IL-6 greater than 9,000 pg/mL. Alpha-defensin is not affected by prior antibiotics. Only when I am confident infection is ruled out do I proceed with aseptic revision. If infection confirmed, I perform 2-stage exchange with explantation, antibiotic spacer, IV antibiotics for 6-12 weeks, then reimplantation.
VIVA SCENARIOStandard

EXAMINER

"Describe the Paprosky acetabular classification system in detail and explain how it guides your reconstruction strategy for each type."

EXCEPTIONAL ANSWER
Paprosky classification categorizes acetabular bone loss to guide reconstruction. Type I is minimal bone loss with intact rim, intact columns, and less than 2cm superior migration - I use standard hemispherical uncemented revision cup 1-2mm oversize for press fit with posterosuperior screws, 90-95% survival at 10 years. Type IIA has intact rim and columns but 2-3cm superior migration with distorted hemisphere - I prefer jumbo cup 66-74mm to span the distortion and achieve greater than 50% host bone contact, 85-90% survival. Type IIB has greater than 25% segmental rim deficiency usually posterosuperior, columns intact, greater than 3cm migration - I use highly porous metal augments (trabecular tantalum or titanium) to convert the uncontained segmental defect to a contained defect, fix augments with screws, then ream and insert revision cup spanning native bone and augment with multiple screws, 80-85% survival. Type IIC has medial wall deficiency with rim preserved - I use medial bone grafting with morselized allograft, then ream and cup with screws, 80-85% survival. Type IIIA has greater than 50% rim loss but ischium and teardrop still identifiable - options include large jumbo cup 70-80mm with extensive augments, OR cup-cage construct with antiprotrusio cage fixed to ilium and ischium then cemented cup within cage, 75-80% survival. Type IIIB is massive bone loss with teardrop obliterated, Kohler's line violated, ischial osteolysis - my preference is custom triflange with patient-specific flanges to ilium/ischium/pubis, 85-90% survival emerging data, alternatives include cup-cage with massive augments or structural allograft, 60-75% survival. If pelvic discontinuity present at any level, I MUST plate the posterior column with reconstruction plate before any cup reconstruction.
VIVA SCENARIOStandard

EXAMINER

"You have completed acetabular revision with excellent component positioning and stability testing looks marginal with the standard liner. The patient has a history of two previous dislocations. How do you address instability risk in this revision?"

EXCEPTIONAL ANSWER
Given the history of two previous dislocations and marginal stability intraoperatively, this patient has high instability risk and I would NOT accept marginal stability - revision dislocation rates are 10-20% with standard liners but instability is preventable. My first-line strategy is dual mobility liner which reduces dislocation from 10-20% to 2-3% through a large outer bearing that increases jump distance and allows greater ROM without impingement. Dual mobility has superior outcomes compared to constrained liners with lower loosening risk and no increased torque to shell fixation. I would change from standard to dual mobility liner. Additionally, I optimize soft tissues - meticulous capsular repair when tissue available reduces dislocation 3-4x, repair short external rotators to greater trochanter posteriorly with transosseous sutures, critically assess abductor mechanism and repair any deficiency because abductor insufficiency is a major instability risk factor. I verify component position is within Lewinnek safe zone - 40-45° inclination, 15-20° anteversion - because malposition is the most common cause of instability. I assess femoral version - excessive anteversion causes anterior instability, excessive retroversion causes posterior instability. I check for impingement throughout full ROM - component or bone impingement causes levering out and dislocation. I assess leg length - some lengthening 1-2cm acceptable for soft tissue tension and stability. After all optimization, I re-test stability and should have EXCELLENT stability not marginal - 90° flexion with internal rotation and adduction should be rock solid. Post-operatively strict hip precautions for 12 weeks, patient education about dislocation risk and precautions compliance, close follow-up.

Revision Acetabular Component - High-Yield Exam Summary

High-Yield Exam Summary

References

  1. Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Hip, Knee & Shoulder Arthroplasty: 2023 Annual Report. Adelaide: AOA, 2023. Available at: https://aoanjrr.sahmri.com/annual-reports-2023

  2. 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. doi:10.1016/0883-5403(94)90135-x

  3. Garbuz DS, Morsi E, Mohamed NN, Gross AE. Classification and reconstruction in revision acetabular arthroplasty with bone stock deficiency. Clin Orthop Relat Res 1996;(324):98-107. doi:10.1097/00003086-199603000-00013

  4. 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. doi:10.1016/j.arth.2006.05.015

  5. Abdel MP, Lewallen DG, Berry DJ. Periprosthetic joint infection: the role of dual mobility implants in total hip arthroplasty. Bone Joint J 2014;96-B(11 Suppl A):60-63. doi:10.1302/0301-620X.96B11.34333

  6. Berend KR, Lombardi AV, Mallory TH, et al. The long-term outcome of 755 consecutive constrained acetabular components in total hip arthroplasty: examining the successes and failures. J Arthroplasty 2005;20(7 Suppl 3):93-102. doi:10.1016/j.arth.2005.06.001

  7. DeBoer DK, Christie MJ, Brinson MF, Morrison JC. Revision total hip arthroplasty for pelvic discontinuity. J Bone Joint Surg Am 2007;89(4):835-840. doi:10.2106/JBJS.F.00313

  8. Villatte G, Erivan R, Barbet R, et al. Efficacy and safety of antibiotic-loaded bone cement in the prevention of periprosthetic joint infection after total hip arthroplasty: a systematic review and meta-analysis of randomized controlled trials. J Bone Joint Surg Am 2020;102(7):634-640. doi:10.2106/JBJS.19.00759

  9. Tarity TD, Koch CN, Burket JC, Wright TM, Westrich GH. Fretting and corrosion at the backside of modular cobalt chromium acetabular inserts: a retrieval analysis. J Arthroplasty 2017;32(3):1033-1039. doi:10.1016/j.arth.2016.09.038

  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):870-876. doi:10.1302/0301-620X.91B7.22181