Acetabular Insertion With Bone Grafting

1. High-Yield Summary

• Primary Clinical Indication: Moderate to severe acetabular bone loss (Paprosky Type II cavitary, Type III combined cavitary and segmental deficiencies) encountered during revision total hip arthroplasty (THA) or complex primary arthroplasty requiring biological restoration of host bone stock and durable cup fixation.
• Critical Move: Converting uncontained segmental wall or dome defects into a fully contained hemispherical cavity using rigid contoured wire mesh or porous metal augments, followed by dense, multi-directional impaction of 7 to 10 mm washed cancellous allograft chips until the aggregate resists further deformation, verified by high-pitched acoustic resonance upon mallet strike.
• Catastrophic Error to Avoid: Seating an acetabular component onto uncontained, poorly impacted, or fibrous-infiltrated graft beds without achieving at least 50% native host bone contact or rigid structural augment support, which induces early superomedial migration, graft shear collapse, and construct failure.

2. Indications and Contraindications

Absolute Indications

• Aseptic loosening of an acetabular component accompanied by substantial contained cavitary (Paprosky Type IIA, IIB, IIC) or combined cavitary and segmental (Paprosky Type IIIA, IIIB) bone loss.
• Severe periacetabular osteolysis compromising the structural columns or medial acetabular wall where standard hemispherical uncemented cups cannot achieve reliable press-fit stability.
• Young, active patients (under 60 years of age) with significant bone deficiency where restoring the native bone stock is essential to preserve biological options for subsequent reconstructive procedures.
• Severe primary dysplastic osteoarthritis (Crowe Type III or IV) or post-traumatic acetabular nonunion requiring restoration of the true anatomic hip center of rotation.

Relative Indications

• Pelvic discontinuity managed with rigid posterior column plate fixation combined with impaction allografting and a cemented cup or cup-cage construct.
• Severe segmental column defects reconstructed with modular porous metal (tantalum or titanium) augments where residual cavitary spaces require supplemental impacted cancellous bone grafting.

Contraindications

• Absolute: Active or untreated periprosthetic joint infection (PJI), local soft-tissue sepsis, or positive intraoperative frozen section margins requiring staged debridement.
• Absolute: Incomplete debridement leaving necrotic bone, wear particulate granulomas, or infected biofilm within the host bed.
• Relative: Massive uncontained acetabular defects (Paprosky Type IIIB with greater than 50% circumferential column loss) lacking sufficient structural pelvic columns to support mesh fixation without supplementary cage or dual-column plating.
• Relative: Prior pelvic radiation therapy or severe metabolic bone disease impairing biological host revascularization and creeping substitution, in which case porous metal augments or custom triflange implants are preferred.

3. Preoperative Planning & Defect Classification

Imaging Review & CT Defect Mapping

Accurate assessment of periacetabular bone stock requires comprehensive radiographic evaluation. A low anteroposterior (AP) pelvis radiograph centered on the pubic symphysis, accompanied by a dedicated cross-table lateral and Judet 45-degree iliac and obturator oblique views, allows evaluation of anterior and posterior column continuity, teardrop disruption, and iliopectineal and ilioischial line integrity.

Preoperative high-resolution computed tomography (CT) with metal artifact reduction software (MARS) is mandatory for complex revisions. Thin-slice volumetric CT scans precisely map the dimensions of superior dome osteolysis, medial wall erosion, and ischial bone loss. Multiplanar 3D reconstructions are evaluated to detect occult pelvic discontinuity, identified by rotational mismatch between the superior ilium and the inferior ischiopubic segment.

Paprosky and AAOS Defect Classification

Periacetabular defects are systematically classified using the Paprosky and American Academy of Orthopaedic Surgeons (AAOS) systems to dictate the surgical reconstruction strategy:

Paprosky Defect Type	AAOS Category	Anatomical Bone Loss Pattern	Teardrop / Medial Wall Integrity	Recommended Reconstruction Strategy
Type I	Type II (Cavitary)	Intact acetabular rim, minimal localized subchondral bone loss, no migration.	Intact teardrop; intact Kohler’s line.	Standard press-fit hemispherical cup or minimal cavitary morselized graft.
Type IIA	Type II (Cavitary)	Superior cavitary lysis with intact superior rim; mild oval defect.	Intact teardrop; Kohler’s line intact.	Impaction bone grafting with cemented cup or slightly oblong press-fit cup.
Type IIB	Type I & II (Combined)	Superolateral rim defect (<1/3 circumference); intact anterior/posterior columns.	Intact teardrop; mild superior migration (<2 cm).	Contoured rim mesh or porous augment + impaction bone grafting + cemented cup.
Type IIC	Type II (Cavitary)	Medial wall breach; migration medial to Kohler’s line with intact rim.	Lysis of teardrop; Kohler’s line violated.	Medial wire mesh + impaction bone grafting + cemented cup to restore center of rotation.
Type IIIA	Type I & II (Severe)	Superior dome loss (10 to 2 o’clock); moderate column lysis; migration >2 cm.	Moderate teardrop lysis; ischial lysis minimal.	Structural porous augment or heavy mesh + robust impaction grafting + cup.
Type IIIB	Type I, II & IV (Massive)	Severe bone loss (9 to 5 o’clock); >50% circumferential column loss; severe ischial lysis.	Complete teardrop destruction; severe medial violation.	Reconstruction cup-cage, porous metal augments, or custom triflange + bone graft.

Equipment and Allograft Preparation Checklist

• Allograft Material: 1 to 3 fresh-frozen, non-irradiated allograft femoral heads from an accredited tissue bank. Donors must be screened for viral transmissible diseases.
• Bone Milling Instrumentation: Manual or motorized bone mill producing calibrated 7 to 10 mm cancellous chips. Fine bone meal (<3 mm) must be excluded to prevent structural aggregate collapse.
• Mesh and Fixation: Titanium or surgical-grade stainless steel contourable wire mesh sheets (0.6 to 1.0 mm thickness) and 3.5 mm cortical screws with low-profile heads.
• Impactors and Reamers: Dedicated hemispherical bone graft impactors ranging in diameter from 40 mm to 64 mm in 2 mm increments; matching hemispherical acetabular reamers capable of reverse (counter-clockwise) rotation.
• Cement and Implants: High-viscosity antibiotic-loaded polymethylmethacrylate (ALBC) with third-generation vacuum mixing and silastic pressurization delivery; highly cross-linked polyethylene cemented acetabular components.

Examination Under Anesthesia (EUA)

Prior to skin preparation, perform a gentle examination under anesthesia. Evaluate limb length discrepancy, passive hip flexion and rotation arcs, and gross pelvic instability. Palpate the anatomic landmarks including the anterior superior iliac spine (ASIS), greater trochanter, and posterior superior iliac spine (PSIS) to plan surgical incision corridors.

4. Patient Positioning & Setup

Setup and Patient Orientation

Position the patient in a rigid, true lateral decubitus orientation on a radiolucent surgical table. Secure pelvic stability using a well-padded anterior pubic peg and a posterior sacral peg or a rigid pegboard positioner. Ensure the operative pelvis is oriented precisely perpendicular to the floor to prevent inadvertent errors in component inclination and anteversion.

Place an axillary roll 3 to 4 fingerbreadths inferior to the axilla to unload the brachial plexus. Pad all dependent bony prominences including the contralateral fibular head to safeguard the common peroneal nerve. The operative lower extremity is prepped and draped freely to allow unrestricted hip flexion to 90 degrees, adduction, and internal rotation during joint dislocation and acetabular visualization.

Safety Check & Fluoroscopic Corridors

Confirm that the image intensifier (C-arm) can move freely into the field to obtain clear AP pelvis and obturator/iliac oblique projections without obstruction from pelvic pegs or the operating table base. Verify that sterile suction, pulsatile lavage, and electrocautery lines are secured with adequate slack for extreme hip manipulation.

5. Surgical Approach and Exposure

Posterolateral Approach

The extended posterolateral (Southern) approach provides expansile visualization of the posterior column, acetabular dome, and ischium. Make a curvilinear skin incision centered over the posterior third of the greater trochanter, angling proximally toward the posterior superior iliac spine for 10 to 12 cm and extending distally along the femoral shaft for 10 to 15 cm.

Incise the iliotibial band and bluntly divide the gluteus maximus fibers along their natural orientation. Identify and isolate the sciatic nerve by digital palpation along the posterior aspect of the obturator internus and quadratus femoris. If extensive scar tissue is present from previous surgeries, perform an external neurolysis under direct vision. Protect the nerve with a gentle, non-tensioning malleable retractor, keeping the knee flexed to 60 degrees throughout exposure.

Systematically tag and peel the piriformis, gemelli, and obturator internus tendons from their femoral insertions. Reflect a wide, full-thickness posterior capsular flap and secure stay sutures for anatomic repair during closure. Dislocate the femoral head or modular trunnion gently using flexion, internal rotation, and posterior translation.

Internervous and Intermuscular Planes

The posterolateral approach traverses intermuscular rather than classic internervous planes. The superficial plane utilizes the interval between gluteus maximus fibers (supplied by the inferior gluteal nerve). The deep plane is developed by reflecting the short external rotators (supplied by sacral plexus branches) away from the hip capsule, completely avoiding the anterior internervous plane of the femoral nerve.

Neurovascular Danger Zones

• Sciatic Nerve: Runs immediately posterior to the posterior acetabular column and ischium. Excessive traction during posterior wall retracting, limb internal rotation with full knee extension, or direct thermal injury from electrocautery represents the most common neurological hazard.
• Superior Gluteal Neurovascular Bundle: Exits the pelvis through the greater sciatic notch 2 to 3 cm superior to the acetabular roof. Extreme proximal retraction on the superior ilium or bicortical drilling angled postero-superiorly can lacerate the vessels, resulting in torrential intrapelvic hemorrhage and abductor denervation.
• Obturator Neurovascular Bundle: Traverses the obturator foramen anteroinferior to the transverse acetabular ligament. Deep retractor placement over the inferior rim or medial wall reamer breakthrough puts these structures at risk.
• External Iliac and Femoral Vessels: Lie directly anterior to the anterior acetabular wall and psoas tendon. Overzealous anterior column drilling or anterior retractor tip displacement beyond the anterior capsule risks major vascular injury.

6. Operative Technique: Step-by-Step

Step 1: Exposure and Component Removal

Expose the entire acetabular rim 360 degrees using specialized retractors: place an anterior wall retractor over the anterior lip, a sharp superior dome retractor pinned into the iliac wing, and a blunt ischial retractor resting in the obturator notch. Debride the periprosthetic fibrous pseudocapsule, wear debris, and interfacial membrane surrounding the loose component.

Extract the failed cup with minimal host bone resection. For cemented components, use flexible curved osteotomes and ultrasonic cement removal tools to disrupt the cement-bone interface. For uncemented cups, deploy specialized curved cup-extraction blades (Explant system) hugging the outer shell margin to sever osteointegrated zones without removing viable trabeculae.

Step 2: Cavitary and Segmental Bed Debridement

Curet all granulomatous, osteolytic, and fibrous membranes from the inner acetabular floor and walls until healthy, bleeding cortical and cancellous bone is exposed. Perforate dense, sclerotic eburnated bone beds using a 2.0 mm or 2.5 mm drill bit at 5 mm intervals. These micro-perforations produce the “rosebud” bleeding sign, opening vascular corridors from viable iliac bone into the allograft bed to facilitate biological osteoconduction and creeping substitution.

Step 3: Mesh Placement and Bone Graft Preparation

Contour rigid wire mesh (titanium or surgical stainless steel) to reconstruct any uncontained segmental defect. For medial wall breaches (Paprosky Type IIC), contour a round wire mesh disk slightly larger than the medial defect and place it against the inner wall without screws, allowing bone graft impaction to hold it seated. For superior or posterior rim defects (Paprosky Type IIB, IIIA), shape a rim mesh to reproduce the normal anatomic perimeter and secure it rigidly to healthy iliac bone using multiple 3.5 mm cortical screws. This converts the uncontained defect into a completely contained hemispherical space.

Wash the fresh-frozen allograft femoral head chips (milled to 7 to 10 mm caliber) using warm pulsatile saline (0.9% NaCl at approximately 45°C to 50°C). This critical step elutes immunogenic bone marrow elements, non-viable cellular debris, and free fatty acids, reducing immunogenicity and drastically increasing the mechanical shear strength and compaction density of the graft aggregate.

Step 4: Reverse Reaming and Bone Graft Impaction

Pack the prepared cancellous bone chips into the deep cavitary recesses first, filling the medial defect and any peripheral cysts. Impact the graft aggregate vigorously using hemispherical metal impactors driven by sequential, heavy mallet blows. Begin with smaller impactor calibers to condense the deep graft layers, progressing to larger diameters matching the anatomic acetabulum.

Reverse-ream the graft bed by running the acetabular hemispherical reamer strictly in reverse (counter-clockwise). This non-cutting rotation exerts radial and centrifugal compressive force, smoothing the internal neocavity while compacting the bone chips into a uniform, interlocking mantle conforming to the planned cup geometry without cutting away bone graft.

Step 5: Cup Insertion and Pressurization

Deliver antibiotic-loaded polymethylmethacrylate (ALBC) bone cement into the graft bed during its early dough state. Pressurize the cement for 90 to 120 seconds using a silastic pressurization disc to achieve micro-interlock into the superficial 1 to 2 mm of the impacted graft layer, forming a solid cement-bone composite.

Insert the cemented polyethylene cup using an alignment guide, positioning the cup in 40 degrees of radiographic inclination and 15 degrees of anteversion. Maintain continuous, uniform manual pressure with the cup pusher until full cement polymerization occurs to prevent micro-motion or cement-mantle disruption. Carefully remove all extruded peripheral cement before final setting.

Critical Move

The defining technical step is achieving absolute rigidity of the compacted allograft bed before cement pressurization. Vigorous impaction must be continued until the hemispherical impactor rebounds crisply upon mallet striking, producing an audible, high-pitched metallic resonance without detectable graft translation. If the graft layer exhibits spongy compliance or fluid displacement, additional cancellous chips must be added and impacted until rock-solid stability is established.

7. Pearls and Pitfalls

Pearls

• Warm Saline Lavage: Thoroughly washing bone graft in 50°C saline removes free fat droplets and non-viable marrow elements, increasing graft shear modulus by over 40% and accelerating osteoblast migration.
• Chip Caliber Control: Maintain chip size strictly between 7 mm and 10 mm. Fine morselized paste (15 mm) leave large interstitial voids that compromise mechanical interlocking.
• Sub-Sized Impactor Technique: Use an impactor 2 to 4 mm smaller than the final planned cup diameter during initial deep impaction to ensure maximal density at the periphery and medial floor.
• Reverse Reaming Direction: Never allow the surgical assistant or scrub technician to set the power handpiece in forward rotation; mark the reamer control to guarantee counter-clockwise rotation only.

Pitfalls

• Forward Reaming of Graft: Running reamers forward violently shreds the newly formed graft mantle, tears away the perimeter mesh, and necessitates complete re-grafting.
• Uncontained Medial Extrusion: Inadequate medial mesh containment allows pressurized liquid cement or graft chips to push into the true pelvis, jeopardizing the obturator neurovascular bundle or internal iliac vein.
• Early Dynamic Loading: Permitting unrestricted full weight-bearing before radiographic evidence of graft trabecular incorporation risks early component migration and aseptic failure.
• Failure to Perforate Sclerotic Bone: Seating graft against dense, avascular sclerotic bone without drill perforation creates an impenetrable barrier to vascular ingrowth, resulting in graft death and non-incorporation.

8. Postoperative Care and Rehabilitation

Immediate Postoperative Protocol

Initiate touch-down weight-bearing (TDWB; approximately 10 to 15 kg of foot-flat contact) using crutches or a walker on postoperative day one. TDWB is strictly maintained for 6 to 12 weeks to protect the biological graft remodeling process from excessive cyclical shear stresses during the vulnerable revascularization phase.

Administer pharmacologic venous thromboembolism (VTE) prophylaxis (direct oral anticoagulants, low-molecular-weight heparin, or aspirin according to individual patient risk stratification) for 35 days. Provide extended perioperative intravenous antibiotic prophylaxis (24 to 48 hours) due to the high volume of foreign allograft tissue.

Phase-by-Phase Rehabilitation Protocol

• Phase I (Weeks 0 to 6): Touch-down weight-bearing with assistive devices. Focus on gentle isometric quadriceps, hamstring, and gluteal muscle activation. Hip dislocation precautions (avoid flexion beyond 90 degrees, adduction past neutral, and internal rotation). Active ankle pumps for edema control and deep venous thrombosis prevention.
• Phase II (Weeks 6 to 12): Obtain follow-up AP pelvis and lateral radiographs. If there is no evidence of cup migration or radiolucent progression, advance to 50% partial weight-bearing with two crutches or a cane. Initiate closed-chain kinetic exercises, pelvic stability training, and gentle active-assisted hip range-of-motion drills.
• Phase III (Weeks 12 to 24): Advance to full weight-bearing as tolerated without assistive devices once mature trabecular bridging and graft remodeling are confirmed on plain radiographs. Focus on progressive resistive gluteus medius strengthening, gait retraining, and low-impact stationary cycling.
• Phase IV (Beyond 24 Weeks): Transition to full, unassisted recreational activities. Encourage low-impact aerobic conditioning including swimming, brisk walking, and cycling. High-impact contact athletics and heavy repetitive manual labor are discouraged.

9. Outcome and Implant Survivorship

Long-term clinical investigations demonstrate that acetabular impaction bone grafting with a cemented polyethylene cup reliably restores bone stock and achieves excellent implant survivorship. Landmark investigations from the Nijmegen group and multi-institutional revision cohorts report overall cup survivorship free of revision for aseptic loosening ranging between 85% and 94% at 10 to 15 years, and 68% to 75% at 25 to 35 years of follow-up.

Serial radiographic evaluations verify successful biological incorporation of impacted morselized cancellous allograft through creeping substitution. Trabecular bridging across the graft-host interface and complete remodeling are typically visible on radiographs within 12 to 24 months. Stable, non-progressive radiolucent lines in DeLee and Charnley zones I and II of less than 2 mm do not correlate with clinical failure if the cup remains in an unchanged anatomic position.

10. Complications and Management

Complex acetabular reconstruction is associated with a distinct complication profile related to the magnitude of exposure, extensive dissection, and reliance on biological allograft incorporation:

Complication	Incidence	Etiology & Risk Factors	Prevention & Salvage Strategy
Early Aseptic Loosening & Cup Migration	3% to 8%	Suboptimal graft compaction, chip size <5 mm, premature weight-bearing, lack of host bone contact.	Rigid mesh containment, multi-directional impaction, strict TDWB for 6-12 weeks; revise with porous augments or cup-cage.
Periprosthetic Joint Infection (PJI)	2% to 5%	Extensive operative duration, prior revision surgeries, high volume of allograft biological tissue.	Rigid sterile protocol, double-gloving, ALBC cement, laminar airflow; two-stage exchange arthroplasty for chronic infection.
Sciatic Nerve Neurapraxia	1% to 3%	Posterior retractor pressure, limb lengthening, traction during dislocation, direct hematoma compression.	Direct palpation of nerve, maintain knee flexed at 60°, release tension; prompt surgical decompression if acute hematoma.
Intraoperative Column Fracture	1% to 2%	Over-vigorous impaction against attenuated columns, excessive reaming, unrecognized osteopenia.	Sub-sized impactors, cautious mallet force; stabilize immediately with 3.5 mm posterior column plates.
Prosthetic Dislocation / Instability	4% to 9%	Component malposition, extensive abductor weakness, prior multiple revisions, impingement.	Target 40° inclination / 15° anteversion, meticulous capsular repair, larger femoral head (32-36 mm), constrained liner salvage.
Heterotopic Ossification	5% to 15%	Extensive abductor and periosteal stripping, male sex, hypertrophic osteoarthritis history.	Copious pulsatile lavage, gentle soft-tissue handling; postoperative indomethacin or single-dose radiation prophylaxis.

11. Complex Reconstructions & Pelvic Discontinuity

Identification of Pelvic Discontinuity

Pelvic discontinuity represents a complete mechanical separation of the superior ilium from the inferior ischiopubic segment, creating independent motion across the transverse pelvic plane. It is encountered in 1% to 5% of complex acetabular revisions and is frequently associated with massive Paprosky Type IIIB defects. Diagnostic recognition requires combining preoperative CT multiplanar reconstructions with intraoperative mechanical testing: placing manual distractors between the anterior and posterior columns reveals pathognomonic independent paradoxical mobility.

Cup-Cage and Porous Metal Augment Reconstruction

Managing pelvic discontinuity demands both rigid mechanical stabilization across the fracture gap and biological defect filling. The reconstruction sequence involves:

• Rigid Internal Fixation: Contouring a 3.5 mm or 4.5 mm low-contact dynamic compression plate along the posterior column from the sciatic buttress to the ischial tuberosity, securing at least three bicortical screws on either side of the discontinuity line.
• Biological Impaction Grafting: Packing the central cavitary defect with impacted cancellous allograft chips to bridge the fracture gap and stimulate osteosynthesis.
• Structural Cup-Cage or Porous Augment Construct: Inserting an uncemented highly porous metal shell or custom cage with superior iliac flange screws and an inferior ischial flange. The cage bridges the discontinuity, protecting the impacted bone graft from cyclical shear while providing stable anchoring for a cemented polyethylene liner.

12. Contemporary Controversies & Graft Alternatives

The management of severe acetabular bone loss continues to evolve, centering on the comparison between biological restoration using impaction bone grafting and modular structural reconstruction using porous metal augments (highly porous tantalum or 3D-printed titanium).

Impaction bone grafting possesses the distinct advantage of biological bone stock restoration: creeping substitution gradually replaces allograft with living, vascularized host trabecular bone, preserving vital bone volume for future surgical revisions in younger patients. However, impaction grafting is technically demanding, requires extended protected weight-bearing, and exhibits higher failure rates when circumferential column support is missing.

Conversely, modular porous metal augments provide immediate, rigid structural support with a high coefficient of friction against viable host bone, enabling earlier postoperative weight-bearing. Modern reconstructive philosophy frequently combines both modalities: porous metal augments are anchored to remaining structural columns to recreate a contained socket, while impacted morselized cancellous allograft is used to backfill cavitary voids and restore anatomic hip center biology.

13. Evidence-Based Synthesis

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

Clinical Question / Investigation	Level of Evidence	Pivotal Landmark Study	Study Design & Methodology	Cohort Size / Follow-up	Primary Outcome / Effect Size	DOI
Survivorship and graft incorporation of acetabular impaction grafting in revision THA	Level I	Patel R, Saadeh K, Bates O et al (2026)	Systematic Review and Meta-Analysis	18 studies (842 hips; mean follow-up 7.8 years)	Pooled 10-year cup survivorship was 92.4% (95% CI: 88.6-95.2%); radiographic bone graft incorporation confirmed in 94.1% without progressive cup migration.	DOI
Ultra-long-term (27 to 35-year) survivorship of acetabular impaction grafting in young patients (<50 years)	Level IV	Schmitz MWJL, Hannink G, Gardeniers JWM et al (2017)	Prospective Longitudinal Cohort Study	33 revisions (28 patients < 50 years; mean follow-up 30.2 years)	30-year survivorship free of revision for any reason was 57% and for aseptic loosening was 68%, confirming biological bone stock restoration in young active patients.	DOI
Long-term (25 to 30-year) implant survivorship using competing risk analysis versus Kaplan-Meier estimates	Level II	Te Stroet MA, Keurentjes JC, Rijnen WH et al (2015)	Competing Risk Comparative Cohort Analysis	62 consecutive revisions (mean follow-up 27.5 years)	25-year cumulative incidence of revision for aseptic loosening was 26.2% when accounting for mortality as a competing risk; extensive trabecular host incorporation verified on long-term radiographs.	DOI
Evaluation and surgical management strategies for severe pelvic discontinuity in revision THA	Level IV	Berry DJ, Lewallen DG, Hanssen AD et al (1999)	Seminal Anatomic Classification and Case Series	31 hips with pelvic discontinuity (mean follow-up 6.4 years)	Pelvic union achieved in 100% of cases treated with rigid posterior column plating combined with structural/impaction bone grafting; defined operative principles for discontinuity.	DOI
Predictors of 10-year implant survivorship in revision THA with porous metal cups, augments, and bone graft	Level IV	Alter TD, Hadley ML, Couch CG, Lewallen DG et al (2024)	Multicenter Longitudinal Cohort Study	247 revision THAs with Paprosky Type II/III defects (10-year follow-up)	10-year cup survivorship free of revision for aseptic loosening was 93.6%; primary host bone contact ≥50% combined with supplemental bone grafting significantly lowered re-revision risk.	DOI
Mid- to long-term clinical durability of half versus full cup-cage constructs combined with morselized allograft	Level IV	Sculco PK, Ledford CK, Hanssen AD, Lewallen DG et al (2017)	Comparative Case-Control Series	87 hips with Paprosky Type IIIB defects (mean follow-up 7.2 years)	10-year survivorship free of revision for aseptic loosening was 89.7%; successful graft consolidation and stable mechanical fixation achieved across severe uncontained column defects.	DOI

14. References

• Patel R, Saadeh K, Bates O et al. The outcomes of acetabular impaction bone grafting using allografts in uncemented cups for acetabular bone loss: a systematic review and meta-analysis. Musculoskelet Surg. 2026. doi:10.1007/s12306-025-00933-6 [Level I: Systematic Review and Meta-Analysis]
• Schmitz MWJL, Hannink G, Gardeniers JWM et al. Acetabular Reconstructions with Impaction Bone-Grafting and a Cemented Cup in Patients Younger Than 50 Years of Age: A Concise Follow-up, at 27 to 35 Years, of a Previous Report. J Bone Joint Surg Am. 2017. doi:10.2106/JBJS.16.00638 [Level IV: Prospective Longitudinal Cohort Study]
• Te Stroet MA, Keurentjes JC, Rijnen WH et al. Acetabular revision with impaction bone grafting and a cemented polyethylene acetabular component: comparison of the Kaplan-Meier analysis to the competing risk analysis in 62 revisions with 25 to 30 years follow-up. Bone Joint J. 2015. doi:10.1302/0301-620X.97B10.34984 [Level II: Competing Risk Comparative Cohort Analysis]
• Berry DJ, Lewallen DG, Hanssen AD et al. Pelvic discontinuity in revision total hip arthroplasty. J Bone Joint Surg Am. 1999. doi:10.2106/00004623-199912000-00006 [Level IV: Seminal Anatomic Classification and Case Series]
• Alter TD, Hadley ML, Couch CG, Lewallen DG et al. Highly Porous Acetabular Cup and Augment Constructs in Complex Revision Total Hip Arthroplasty: What Predicts 10-Year Implant Survivorship?. J Arthroplasty. 2024. doi:10.1016/j.arth.2024.03.071 [Level IV: Multicenter Longitudinal Cohort Study]
• Sculco PK, Ledford CK, Hanssen AD, Lewallen DG et al. The Evolution of the Cup-Cage Technique for Major Acetabular Defects: Full and Half Cup-Cage Reconstruction. J Bone Joint Surg Am. 2017. doi:10.2106/JBJS.16.00821 [Level IV: Comparative Case-Control Series]

15. Master Class Pro-Tip

When reconstructing severe cavitary acetabular defects with impaction bone grafting, converting an uncontained defect into a completely contained cavity is non-negotiable. Always contour and rigidly screw-fix titanium mesh or porous metal augments to sound iliac bone before introducing a single chip of allograft. Thoroughly wash the 7 to 10 mm morselized chips in 50°C saline to elute marrow fat and immunogenic proteins. Pack the graft aggregate centrifugally, beginning at the medial floor and proceeding to the periphery. Drive the hemispherical impactors with sequential, forceful mallet strikes until the impactor rebounds with an audible, high-pitched metallic ring and zero observable displacement. When reverse-reaming to smooth the neocavity, never engage the handpiece in forward rotation, as the reamer flutes will instantaneously shred and excavate the compacted aggregate.

Master Class Surgical Pearl: Acetabular Reconstruction