Revision Total Hip Replacement - Femoral Component

The decision to revise a femoral component rests on a confirmed reason for failure, a rigorous exclusion of infection, and an honest assessment of how much femoral bone is left. Get those three things right and the operation almost plans itself.

Imaging - Plain radiographs - AP pelvis, lateral hip, and FULL-LENGTH AP and lateral femur (mandatory). Assess the femoral bow, canal diameter at several levels, bone stock, fractures, perforations, cortical defects and cement extent; measure leg-length discrepancy (lesser trochanter to ischial tuberosity) and template stem length and diameter.

• Scanogram - if a significant leg-length discrepancy is suspected, to measure true lengths with magnification correction.
• CT - for severe bone loss (3D planning); delineate osteolysis and cortical defects, cement distribution and distal plugs, and plan cortical windows for cement removal.
• MRI - if adverse reaction to metal debris is suspected (metal-artifact reduction sequences); assess soft-tissue pseudotumour and abductor integrity. ### Implant planning checklist

Setup. Lateral decubitus, affected side up, pelvis perpendicular to the floor with rigid anterior and posterior supports (confirm with an alignment rod or fluoroscopy). Radiolucent table so the C-arm can reach the hip and full femur. Use the previous incision where possible.

The goal is to expose the femur through the posterior approach, remove the failed component and cement without fracturing the femur, classify the bone loss, and place a stem that achieves stable fixation in whatever healthy diaphysis remains - protecting the sciatic nerve throughout. The exposure, and especially the extended trochanteric osteotomy, is the heart of the operation: it is what makes safe extraction and distal access possible.

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Post-operative protocol - Weight bearing - touch-down or partial weight bearing (20-30kg) for 6-12 weeks after an ETO or strut grafting; advance to weight bearing as tolerated once radiographic healing (callus, pain-free), typically 8-12 weeks. A proximal femoral replacement allows immediate weight bearing.

• Radiographic follow-up - films at 6 weeks (callus, cable position), 3 months (usually healed), then 6 and 12 months and annually. An asymptomatic ETO not healed at 3 months can be watched with protected weight bearing to 6 months.
• Hip precautions for 12 weeks; DVT prophylaxis (LMWH or DOAC) for 4-6 weeks; early mobilisation.

Further complications - Leg-length discrepancy (10-15%) - common from bone loss and soft-tissue laxity; aim within 1cm. Some lengthening (1-2cm) is acceptable for stability if the nerve is not tight; greater than 4cm raises palsy risk. Shoe lift if less than 2cm; revision if greater than 3cm and symptomatic.

• Chronic thigh pain (10-20%) - commoner with extensively coated stems (distal stress transfer); usually mild and improves over 1-2 years as osseointegration occurs. NSAIDs and reassurance; re-revision rarely.
• DVT/PE (2-3%) - higher than primary due to longer surgery and more blood loss. LMWH or DOAC for 4-6 weeks, early mobilisation, compression. Duplex for DVT, CT pulmonary angiography for PE; anticoagulate.
• Blood loss and transfusion (30-50% transfused; 500-1000mL loss) - tranexamic acid 1g IV pre-incision and 1g at closure, cell saver, meticulous haemostasis; transfuse if haemoglobin less than 70 or symptomatic.
• Heterotopic ossification (5-10% with prophylaxis) - risk in revision, extensive dissection, men, previous HO. Indomethacin 75mg daily for 6 weeks or single-dose radiation 700 cGy within 24 hours. Excise severe (Brooker III-IV) restriction after maturation (12-18 months).
• Abductor insufficiency and Trendelenburg gait (5-10%) - superior gluteal nerve injury, abductor detachment or non-healing, GT non-union or escape. Protect the nerve (avoid dissection greater than 5cm above the GT), repair abductors securely, ensure ETO healing; therapy plus or minus a cane, and reconstruction if severe.

Epidemiology. Femoral revision accounts for a substantial share of the revision burden recorded across the AOANJRR, the NJR (England, Wales and Northern Ireland), the AJRR, the Swedish/SHAR and the Norwegian registries. Aseptic loosening is the single commonest indication (about 40-50%). Registry evidence consistently shows that cementless extensively coated and modular tapered revision stems outperform cemented revision in survivorship, and that outcomes deteriorate as the Paprosky grade rises (Type I and II better than Type III and IV). These registries are used here as global outcome evidence, not as single-country practice. ### Paprosky femoral classification (the framework that drives the operation)

• Modular tapered stems - a distal taper self-locks by compression in the diaphysis and longitudinal flutes give rotational stability; the proximal modular body allows intraoperative offset and version adjustment. Excellent for Type IIIA/B; modular-junction corrosion is rare.
• Impaction bone grafting - morselised allograft impacted into metaphyseal defects, contained by mesh or cortical strips; biological augmentation that may incorporate.
• Cortical strut grafts - fibular or femoral-shaft allografts for perforations, fractures or thin cortex; span the defect by 2 cortical diameters and fix with 2-3 cerclage cables per strut.
• Proximal femoral replacement (megaprosthesis) - for Type IV; long distal stem in healthy mid or distal femur, modular proximal body, and abductor reattachment to the collar. Allows immediate weight bearing but higher complications (dislocation 10-20%, infection 5-10%, aseptic loosening 10-15%, abductor failure 15-20%).
• Allograft-prosthesis composite - for younger patients (typically less than 60 years) wanting a biological solution; stem cemented through a structural allograft into host bone, junction plated, soft tissues attached to the graft. Higher complication rate (non-union 10-20%, fracture 15-20%, resorption 10-15%, infection 5-10%) and 10-year survival only 60-70%.

Further reading 1. Wagner H, Wagner M. Cone prosthesis for the hip joint. Arch Orthop Trauma Surg. 2000;120:88-95. Original Wagner cone (modular tapered) stem - the self-locking taper that achieves diaphyseal fixation. 2. Mumme T, Muller-Rath R, Andereya S, et al. Uncemented femoral revision arthroplasty using a modular tapered, fluted titanium stem: 5- to 16-year results of 163 cases. Acta Orthop. 2007;78(4):454-460. 83% survival at 10 years; subsidence the main failure mode when diaphyseal fixation is inadequate. 3. National joint replacement registries (AOANJRR, NJR England, Wales and Northern Ireland, AJRR United States, Swedish/SHAR, Norwegian, NZJR). Pooled registry evidence: cementless extensively coated and modular tapered femoral revision stems consistently outperform cemented revision in survivorship; outcomes deteriorate with increasing Paprosky grade. Used as global outcome evidence, not as single-country practice. 4. Haddad FS, Masri BA, Garbuz DS, Duncan CP. The prevention of periprosthetic fractures in total hip and knee arthroplasty. Orthop Clin North Am. 1999;30(2):191-207. Prevention strategies - ETO for well-fixed stems, cortical strut grafts for defects, appropriate stem sizing. 5. Springer BD, Berry DJ, Lewallen DG. Treatment of periprosthetic femoral fractures following total hip arthroplasty with femoral component revision. J Bone Joint Surg Am. 2003;85-A(11):2156-2162. Vancouver B management in revision - B1 ORIF preserve stem, B2 revision to longer stem plus ORIF, B3 long stem or PFR plus strut grafts.