Implant Removal – Femoral Component

Archival Presentation Notice: This article modernizes the multimedia presentation “Implant Removal: Femoral Component” originally presented by David K. DeBoer, MD (Southern Joint Replacement Institute, Nashville, TN) at the International Congress for Joint Reconstruction (ICJR). The historical Flash lecture has been reconstructed into the synchronized video slide presentation above, with the original file preserved in the digital archives (Implant_Removal_Femoral_Component_DeBoer.swf).

1. High-Yield Summary

Femoral component removal in revision total hip arthroplasty (THA) represents one of the most technically demanding stages of reconstructive hip surgery. The primary objective is the safe, controlled extraction of the failed prosthesis while preserving maximum host bone stock for subsequent revision stem reconstruction.

• Primary Indication: Failed femoral stem due to aseptic loosening, periprosthetic joint infection (PJI), periprosthetic femur fracture (Vancouver B2/B3), recurrent instability with uncorrectable component malposition, or structural implant fracture.
• The Critical Move: Selective circumferential release of the proximal bone-implant or cement-implant interface, accompanied by prophylactic cerclage placement before executing an extended trochanteric osteotomy (ETO) or applying retrograde extraction forces.
• Catastrophic Error to Avoid: Forcing extraction against an intact distal osseointegrated interface or overhanging trochanteric cortical bone, precipitating uncontrolled femoral shaft fracture, greater trochanter avulsion, or diaphyseal blowout.
• Fixation Strategy: Tailoring extraction maneuvers to implant geometry and fixation type: simple extraction for debonded cemented stems, specialized ultrasonic cement removal tools for well-interdigitated cement mantles, flexible osteotomes for metaphyseal ingrowth stems, and controlled ETO for extensively porous-coated stems.

2. Indications

Removal of a femoral stem is dictated by clinical failure, mechanical loosening, structural compromise, or the necessity for complete debridement during infectious staging.

Absolute Indications

• Aseptic Loosening: Progressive prosthetic subsidence, progressive radiolucent lines >2 mm at the bone-cement or bone-implant interface, component shift, or thigh pain attributable to stem micromotion.
• Periprosthetic Joint Infection: Chronic biofilm colonizing the implant surface requiring one-stage or two-stage exchange arthroplasty with complete component and cement clearance.
• Periprosthetic Femur Fracture: Vancouver Type B2 (loose stem, adequate bone) and Vancouver Type B3 (loose stem, severely deficient bone) fractures requiring stem exchange to bridge the defect.
• Structural Implant Failure: Fatigue fracture of the femoral neck, trunnion fracture, or mid-stem fracture of a well-fixed or unsupported component.

Relative Indications

• Recurrent Hip Instability: Uncorrectable femoral component retroversion or anteversion, marked limb length discrepancy, or severe horizontal offset deficiency when head-neck adjustments prove insufficient.
• Severe Trunnion Corrosion (Trunnionosis): Progressive mechanically assisted crevice corrosion at the head-neck taper causing adverse local tissue reaction (ALTR) or metallosis when cold welding or corrosion damages taper integrity.
• Revision for Isolated Acetabular Reconstruction: Well-fixed femoral components obstructing straight-line acetabular exposure or screw placement in complex pelvic discontinuity, though retention is preferred if access permits.

Contraindications

• Well-Fixed Asymptomatic Stem: Unnecessary removal of a well-fixed, well-aligned stem during isolated acetabular revision or periprosthetic Vancouver A fracture management.
• Severe Medical Instability: Uncompensated systemic sepsis, acute myocardial infarction, or severe coagulopathy precluding lengthy operative reconstruction until stabilized.

3. Preoperative Planning

Preoperative templating and surgical reconnaissance are paramount to anticipate the interface mechanics, required extraction instrumentation, and necessary reconstructive inventory.

Imaging Review

• Radiographic Survey: Full-length AP pelvis, AP of the affected femur, cross-table lateral of the hip, and full-length lateral of the entire femur with magnification calibration.
• Implant Identification: Identify the exact stem model, metallurgical composition (cobalt-chromium vs. titanium alloy), surface finish (smooth polished, satin, grit-blasted, hydroxyapatite-coated, or porous-coated), and proximal modularity. Obtain operative reports whenever possible.
• Bone Stock & Fixation Zone Assessment: Determine the Paprosky femoral bone loss grade (Type I, II, IIIA, IIIB, or IV). Identify whether fixation is proximal (metaphyseal) or distal (diaphyseal cylindrical). Assess the cortical thickness and quality at the isthmus.
• Cement Mantle Topography: In cemented stems, examine the integrity of the cement mantle, distal cement restrictor position, and presence of distal cement column fractures or cortical perforations.

Equipment Checklist

• Universal Extraction Toolkits: Threaded collet extractors, Bohn slide-hammer extractors, loop extractors, and hook extractors.
• Thin Flexible Osteotomes: Specialized straight and curved flexible revision osteotomes designed to track implant geometries without skiving into cortical bone.
• High-Speed Carbide & Diamond Burrs: High-speed pencil burrs (Midas Rex or Hall) with long-shank carbide burs to cut cement or carve bone corridors around the implant shoulder.
• Ultrasonic Cement Extraction Systems: Ultrasonic cement removal instrumentation (OSCAR) with dedicated osteotomes and canal scrapers to liquefy and extract well-bonded acrylic cement.
• Cerclage Protection Systems: Cobalt-chromium and titanium cables, crimps, cable passers, and tensioners to prophylactically protect the femur against hoop stress fractures.
• Trephine Reamers: Sized cylindrical trephines for circumferential coring of well-fixed cylindrical stems.

Examination Under Anesthesia (EUA)

Perform an intraoperative examination under anesthesia to evaluate hip range of motion, fixed flexion or adduction contractures, limb length discrepancy, and gross mechanical instability prior to positioning and sterile preparation.

4. Patient Positioning & Setup

Controlled positioning ensures comprehensive access to the proximal femur and unrestricted distal exposure if an extended trochanteric osteotomy or femoral windowing is mandated.

• Patient Orientation: Lateral decubitus position on a radiolucent operating table, secured with anterior pubic and posterior sacral padded positioners.
• Padding & Nerve Protection: Axillary roll placed below the dependent axilla to protect the brachial plexus. Dependent peroneal nerve and pressure points padded meticulously.
• Draping Corridor: Sterile prep and drape extending from the lower rib cage and iliac crest distally down to the toes. The entire lower extremity must be draped free into a sterile stockinette to permit unrestricted intraoperative flexion, adduction, and internal/external rotation.

Safety Check

Ensure that intraoperative fluoroscopy (C-arm) can seamlessly enter the field from the opposite side of the table to provide orthogonal AP and lateral views of the entire femoral shaft from the greater trochanter to the distal metaphysis.

5. Approach

The surgical approach must permit direct in-line visualization of the femoral canal and allow rapid, safe distal extensibility.

Posterolateral (Moore/Southern) Approach

• Skin Incision: Straight lateral incision centered over the greater trochanter, curved gently posteriorly over the gluteus maximus proximally, and extended distally along the lateral shaft of the femur.
• Internervous & Intermuscular Plane: The gluteus maximus is split along its muscle fibers in the line of the inferior gluteal nerve. Distally, the iliotibial band is incised in line with its fibers.
• Short External Rotators & Capsule: The piriformis, obturator internus, and gemelli are tagged with non-absorbable sutures and detached from their femoral insertions, followed by a generous T-shaped or H-shaped posterior capsulotomy.
• Vastus Lateralis Mobilization: The posterior origin of the vastus lateralis is elevated from the lateral intermuscular septum to expose the lateral femoral cortex when distal extension or an ETO is anticipated.

Direct Lateral (Hardinge / Transgluteal) Approach

• Alternative approach for patients with recurrent anterior instability or compromised posterior tissues. Utilizes the intermuscular interval through the anterior half of the gluteus medius and vastus lateralis, with nerve protection directed at the superior gluteal nerve 3 to 5 cm proximal to the trochanteric tip.

6. Technique

Femoral component removal requires systematic, step-by-step deconstruction of the bone-implant or cement-implant construct. Aggressive unguided impaction is strictly avoided.

Step 1: Joint Dislocation & Proximal Reconnaissance

• Dislocate: Flex, adduct, and internally rotate the limb to dislocate the femoral head from the acetabular liner.
• Disassemble Modular Head: Place a dedicated head separator or universal head-distractor tool between the trunnion base and the prosthetic head. Apply controlled axial distraction to remove the modular femoral head. Inspect the taper for cold welding, deformation, or fretting wear.
• Clear Proximal Overhang: Debride surrounding synovium, fibrous pseudocapsule, and heterotopic bone. Using a pencil burr or small osteotome, meticulously resect all overhanging cortical bone from the proximal-lateral greater trochanter overlying the shoulder of the femoral component. Failure to resect this bone causes trochanteric fracture when the stem moves axially.

Step 2: Removal of Loose Stems (Cemented and Cementless)

• Disrupt Proximal Collar Interface: Direct fine flexible osteotomes along the medial calcar and lateral shoulder of the implant.
• Attach Axial Extractor: Mount a universal stem extractor, loop extractor around the neck, or threaded adapter into the extraction hole on the implant shoulder.
• Apply In-Line Retrograde Impaction: Strike the slide hammer strictly parallel to the longitudinal axis of the femoral shaft. Verify that the stem is advancing with each blow. If the component does not translate after 4 to 5 controlled strikes, halt immediately; the stem is bonded distally and requires formal interface clearance.

Step 3: Cement Mantle Debridement

• Segment the Proximal Mantle: Use thin, sharp longitudinal splitters and reverse-cutting chisels to fragment the proximal cement mantle into longitudinal columns, preventing full-ring wedging.
• Ultrasonic Cement Extraction: Deploy ultrasonic transducers (OSCAR) along the cement-bone interface to soften and vaporize acrylic polymethylmethacrylate (PMMA) without creating thermal necrosis in host bone.
• Distal Plug Removal: Core the distal cement plug using specialized drill guides and screw-in extractor taps. If the plug is resistant, create a distal cortical window or utilize an extended trochanteric osteotomy to extract the distal plug under direct vision.

Step 4: Removal of Well-Fixed Porous-Coated Stems

• Proximal Metaphyseal Ingrowth Stems: Use thin, flexible osteotomes (straight and curved) to circumnavigate the proximal 3 to 5 cm of porous coating. Cut bone within 1 mm of the implant surface, prioritizing the medial calcar, anterior, and posterior flanges. Once the proximal sleeve or porous pad is cleared, the smooth distal stem will slide free.
• Extensively Porous-Coated Stems: When the cylindrical porous surface extends along the diaphysis, blind osteotome passage carries a severe risk of cortical perforation and fracture. An Extended Trochanteric Osteotomy (ETO) is the standard of care.

Step 5: Extended Trochanteric Osteotomy (ETO)

• Prophylactic Distal Cerclage: Pass and tighten a prophylactic cerclage cable approximately 1 to 2 cm distal to the planned osteotomy level. This provides hoop tension and prevents longitudinal propagation of fracture lines into the diaphysis.
• Determine Osteotomy Dimensions: The osteotomy spans from the posterior border of the greater trochanter distally down the lateral femur, typically 12 to 15 cm in length, terminating at or just above the distal tip of the stem. Ensure at least 4 to 5 cm of intact cylindrical diaphyseal bone remains distal to the osteotomy to achieve stable scratch-fit fixation for the revision stem.
• Osteotomy Execution: Perform a longitudinal cut along the posterolateral cortex with a sagittal saw or pencil burr. Drill rounded corner drill holes at the distal transverse boundary to prevent stress risers. Complete the distal transverse cut over approximately one-third of the femoral circumference. Create an anterior longitudinal cut.
• Hinge and Elevate: Gently elevate the osteotomy fragment from posterior to anterior, preserving all anterior periosteal and vastus lateralis muscle attachments. Lever the bone plate open to expose the anterior and lateral aspects of the stem directly.
• Circumferential Release & Extraction: Under direct visualization, pass flexible osteotomes and high-speed burrs around the remaining medial and posterior porous surfaces. Disengage the implant cleanly along its longitudinal axis.

Critical Move

The single critical move is placing a rigid prophylactic cerclage cable distal to the planned osteotomy or window before applying levering or extraction forces. This simple maneuver eliminates uncontrolled spiral propagation into the distal femoral diaphysis, which would otherwise convert a manageable revision into a catastrophic reconstructive challenge.

7. Pearls and Pitfalls

8. Postoperative Care

Postoperative rehabilitation protocols are dictated by the reconstructive construct, stability of the revision stem, and whether an extended trochanteric osteotomy or cortical window was repaired.

Immediate Protocol

• Weight-Bearing Status: Touchdown or partial weight-bearing (20–30 lbs) with crutches or a walker for 6 weeks when an ETO or structural cortical window is secured with cerclage cables. Weight-bearing as tolerated may be permitted for stable revisions without cortical disruption.
• Abductor Protection: Avoid active hip abduction against gravity and passive adduction beyond midline for 6 weeks to protect the re-approximated greater trochanter and abductor tendon healing.
• Venous Thromboembolism Prophylaxis: Mechanical compression devices and pharmacologic anticoagulation (low-molecular-weight heparin, direct oral anticoagulants, or aspirin per institutional protocol) maintained for 4 to 6 weeks.

Rehabilitation Protocol Timeline

• Phase I (Weeks 0–6): Strict touchdown weight-bearing; gentle passive and active-assisted range of motion within safe planes (flexion <90°, avoid combined flexion-internal rotation); isometric quadriceps and gluteal contractions.
• Phase II (Weeks 6–12): Advance to 50% partial weight-bearing upon radiographic confirmation of early osteotomy callus. Initiate active hip abduction in the supine position and progressive closed-chain exercises.
• Phase III (Weeks 12–24): Transition to full weight-bearing as tolerated; cane support until Trendelenburg limp resolves. Progressive resistive strengthening and proprioceptive gait retraining.
• Phase IV (>6 Months): Maintenance strengthening, low-impact recreational activity, and long-term surveillance.

9. Outcome

Modern extraction protocols, combined with controlled osteotomies and modular fluted tapered revision stems, yield reproducible outcomes and high rates of biological fixation in revision total hip arthroplasty.

• Osteotomy Healing Rates: Published clinical series demonstrate an extended trochanteric osteotomy radiographic union rate exceeding 96% to 98% at a mean of 8 to 14 weeks postoperatively.
• Revision Stem Stability: Fixation survivorship of modular fluted tapered revision stems following complex femoral extraction exceeds 95% to 98% at intermediate (5- to 7-year) and long-term follow-up.
• Pain and Functional Scores: Patients achieve substantial functional improvements, with mean Harris Hip Scores improving from poor preoperative levels (80 points).

10. Complications

Femoral component removal carries inherent procedural risks that must be anticipated and managed with rapid contingency strategies.

• Intraoperative Femoral Shaft Fracture: Occurs in 3% to 8% of cases, typically from forceful axial extraction or off-axis osteotome driving. Managed by immediate cerclage stabilization and bridging the fracture by at least two cortical diameters with the revision stem.
• Cortical Perforation: Risk is highest during blind reaming or distal cement chipping. Requires fluoroscopic localization, bone grafting, and stem bypass.
• Extended Trochanteric Osteotomy Nonunion: Observed in 1% to 3% of patients, frequently linked to inadequate cerclage compression, extensive devascularization, or excessive postoperative abductor strain. Symptomatic nonunion with trochanteric escape requires revision cable plating or bone grafting.
• Stem Subsidence: Axial subsidence >5 mm occurs in 2% to 5% of revisions, predominantly in severely osteopenic bone (Dorr C) or undersized stems. Prevented by ensuring adequate isthmic scratch fit.
• Sciatic Nerve Injury: Transient neuropraxia occurs in 1% to 2% of complex revisions due to prolonged retractor traction, limb lengthening, or posterior thermal/mechanical injury.

11. 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.

12. References

• Younger TI, Bradford MS, Magnus RE et al. Extended proximal femoral osteotomy. A new technique for femoral revision arthroplasty. J Arthroplasty. 1995. doi:10.1016/s0883-5403(05)80182-2 [Level IV: Retrospective Cohort / Technique Series]
• Mardones R, Gonzalez C, Cabanela ME et al. Extended femoral osteotomy for revision of hip arthroplasty: results and complications. J Arthroplasty. 2005. doi:10.1016/j.arth.2004.10.014 [Level IV: Retrospective Therapeutic Case Series]
• Miner TM, Momberger NG, Chong D et al. The extended trochanteric osteotomy in revision hip arthroplasty: a critical review of 166 cases at mean 3-year, 9-month follow-up. J Arthroplasty. 2001. doi:10.1054/arth.2001.29385 [Level IV: Retrospective Therapeutic Case Series]
• Christie MJ, DeBoer DK, Tingstad EM et al. Clinical experience with a modular noncemented femoral component in revision total hip arthroplasty: 4- to 7-year results. J Arthroplasty. 2000. doi:10.1054/arth.2000.9059 [Level IV: Prospective Therapeutic Cohort]
• Wyles CC, Hannon CP, Viste A et al. Extended Trochanteric Osteotomy in Revision Total Hip Arthroplasty. JBJS Essent Surg Tech. 2023. doi:10.2106/JBJS.ST.21.00003 [Level V: Expert Surgical Technique Guide]

13. Master Class Pro-Tip

When approaching a well-fixed femoral component, never measure operative success by how small of a bone opening you can squeeze the implant through. If a stem does not translate after 4 to 5 controlled retrograde slide-hammer impactions following proximal clearance, immediately transition to an extended trochanteric osteotomy. Always place your prophylactic distal cerclage cable before cutting the bone. Preserving an unviolated, well-vascularized anterior hinge of vastus lateralis guarantees osteotomy union and protects the distal isthmic cylinder, ensuring the revision stem achieves stable, long-term diaphysial osseointegration.