High-yield overview
The final rung of the femoral reconstruction ladder — limb salvage when no viable femoral bone remains between hip and knee
20-30%Deep infection rate in salvage (non-oncologic) series — the highest of any endoprosthetic reconstruction
Household-communityRealistic ambulation expectation, almost always with walking aids
Dual mobility / constrainedAcetabular articulation of choice — dislocation risk is high with absent or deficient abductors
Rotating hingeMandatory knee articulation — collaterals are resected with the femur
vs disarticulationPatients with a total femur consistently report better function and body image than hip disarticulation in selected series
Critical Must-Knows
- Core indication: failed ipsilateral hip and knee arthroplasty with an interprosthetic femoral segment too short or too poor to support stemmed revision components — plus massive oncologic resection, periprosthetic fracture cascade, and infection sequelae.
- It is a salvage operation of last resort before hip disarticulation; the decision is as much about the patient (physiologic reserve, soft-tissue envelope, extensor mechanism, motivation, cognition) as about the bone.
- Soft-tissue management defines function: abductor reattachment (ideally with a trochanteric bone fragment onto the implant, augmented with mesh) and extensor mechanism preservation are the two functional determinants.
- Length and stability are set by soft-tissue tension, not bony landmarks — the femur no longer exists as a reference; use the contralateral limb, pre-resection measurement, and intraoperative tissue tension.
- In infection, a staged approach (total femoral spacer, then definitive endoprosthesis) is standard; single-stage is reserved for a known low-virulence organism with a healthy soft-tissue envelope and an experienced unit.
Clinical Pearls
- “If asked 'what articulation at the hip' — answer dual mobility or a constrained liner, and justify with abductor deficiency; a conventional single-bearing head is the classic wrong answer.
- “Infection is the mode of failure that converts a total femur to disarticulation — quote 20 to 30 percent deep infection in revision-arthroplasty salvage series versus roughly 10 percent in primary oncologic series.
- “Silver-coated and antibiotic-loaded implant surfaces are increasingly used specifically in this population because the infection burden is so high.
Highest-Stakes Points
Infection Dominates
Total femur replacement carries the highest periprosthetic infection rate of any endoprosthesis — 20 to 30 percent in non-oncologic salvage series. Many of these limbs have had multiple prior operations, prior infection, and a scarred, poorly vascularised envelope. Infection after total femur frequently ends in hip disarticulation because there is no remaining bony fallback.
Extensor Mechanism Is Sacred
An intact, functioning extensor mechanism is close to an absolute prerequisite. Loss of active extension after a rotating-hinge total femur produces a limb that buckles and is functionally worse than a well-fitted prosthesis after amputation. Protect the tibial tubercle and patellar tendon at every stage.
Dislocation and Abductors
With the greater trochanter resected or devitalised, abductor function is deficient in almost every case. Use dual mobility or a constrained acetabular construct, reattach abductors to the implant (trochanteric fragment, sutures through implant eyelets, mesh/tube augmentation), and brace early if soft-tissue fixation is tenuous.
Patient Selection Is the Operation
Offer only to patients with the physiologic reserve to survive a long, high-blood-loss procedure, a closable soft-tissue envelope, motivation and cognitive capacity for restricted rehabilitation. In the frail, bed-bound or persistently infected patient, hip disarticulation or acceptance of a flail limb may serve better.
Concept and Position on the Reconstruction Ladder
Total femur replacement (TFR) replaces the entire femur with a modular endoprosthesis articulating proximally with the acetabulum (usually via dual mobility or constrained liner in a cemented or uncemented cup) and distally through a rotating-hinge knee to a stemmed tibial component. The native femur is either excised entirely or retained as a devascularised shell/strut around the implant.
Where it sits on the ladder (each step assumes the previous is not feasible):
- Standard stemmed revision hip or knee arthroplasty
- Proximal or distal femoral replacement (megaprosthesis) with a preserved diaphyseal segment
- Interprosthetic femoral segment too short (commonly quoted as less than roughly 10 cm of viable diaphysis, or bone quality unable to support stem fixation) → total femur replacement
- Hip disarticulation / high transfemoral amputation — the only step beyond TFR
One-line definition for the viva
"Total femur replacement is the final limb-salvage option when there is insufficient viable femoral bone between the hip and knee to support any lesser stemmed reconstruction — the alternative is hip disarticulation."
Indications and Patient Selection
- Failed ipsilateral hip and knee arthroplasty with an interprosthetic segment that is too short, fractured, osteolytic or infected to accept revision stems — the dominant modern indication in adult reconstruction practice
- Massive segmental femoral bone loss: Paprosky IV femoral defects with distal extension, periprosthetic fracture cascade (sequential interprosthetic fractures with failed fixation), non-union with segmental loss
- Oncologic resection: primary bone sarcoma (osteosarcoma, chondrosarcoma, Ewing sarcoma) involving most of the femur or with skip lesions; extensive metastatic destruction in selected patients with reasonable prognosis
- Infection sequelae: after resection of an infected femur/implants where no reconstructable bone remains (usually as second stage)
- Alternative to hip disarticulation where amputation would otherwise be the only option and the patient is fit for salvage
Preoperative Planning
- Imaging: full-length standing (or supine long-leg) femur and pelvis radiographs of both limbs; measure the contralateral femoral length from tip of greater trochanter to joint line — this templates implant length. CT for acetabular bone stock and tibial canal; MRI in oncologic cases for soft-tissue extent and skip lesions.
- Infection workup in every non-oncologic case: CRP/ESR, aspiration of both hip and knee, extended cultures; assume infection until proven otherwise in the failed-arthroplasty cascade.
- Implant: modular total femoral system with rotating-hinge knee; decide acetabular side (retain a well-fixed cup with a dual mobility or constrained liner exchange versus full acetabular revision). Consider silver-coated components in high-infection-risk patients where available.
- Team and logistics: two consultant surgeons, cell salvage, cross-match, plastic surgery on standby for marginal envelopes, HDU bed, tranexamic acid unless contraindicated.
- Discuss disarticulation explicitly in consent — both as the alternative and as the salvage of catastrophic failure.
Length planning
The femur ceases to exist as a length reference once resected. Record planned implant length from the contralateral radiograph before surgery, mark and measure before resection, and finalise with soft-tissue tension intraoperatively. Overlengthening risks sciatic nerve palsy and inability to close; shortening risks instability at the hip.
Staged versus Single-Stage in Infection
First procedure
- Two-Stage (standard)
- Excision of femur/implants, radical debridement, articulating total femoral antibiotic-cement spacer (cement-coated nail/megaspacer)
- Single-Stage (selective)
- Excision, debridement and definitive endoprosthesis in one sitting
Prerequisites
- Two-Stage (standard)
- Default for unknown organism, sinus, resistant organisms, poor host (McPherson B/C)
- Single-Stage (selective)
- Known low-virulence organism with sensitivities, healthy closable envelope, good host, experienced unit
Interval
- Two-Stage (standard)
- 6 weeks or more of targeted IV/oral antibiotics; reimplant when clinically settled and inflammatory markers trending to normal
- Single-Stage (selective)
- Not applicable — prolonged suppressive/targeted antibiotics postoperatively
Advantages
- Two-Stage (standard)
- Higher confidence of eradication; interval reassessment of host and envelope
- Single-Stage (selective)
- One anaesthetic, faster rehabilitation, lower cumulative morbidity in frail patients
Disadvantages
- Two-Stage (standard)
- Spacer instability/dislocation and fracture; interval immobility and deconditioning; two major operations
- Single-Stage (selective)
- Higher reinfection risk if selection is wrong; no second look
A total femoral spacer (antibiotic cement moulded over an intramedullary nail or a cement-coated megaprosthesis) maintains length and some mobility between stages but is itself prone to dislocation and mechanical failure — brace the limb and warn the patient.
Surgical Technique
- Position: lateral decubitus (allows posterior hip access and full lateral femoral exposure) or supine with a bump for combined incisions; the whole limb, hemipelvis and contralateral limb (for length comparison) prepped.
- Approach options:
- Single extended lateral incision from just posterior to the greater trochanter along the lateral femur, curving anteriorly at the knee to allow a lateral or medial parapatellar arthrotomy — the workhorse in salvage cases, incorporating prior scars where possible
- Combined incisions: posterior approach to the hip plus a separate medial or midline/medial parapatellar knee incision — useful when prior scars dictate, at the cost of an intervening skin bridge
- Preparation: cell salvage running; tourniquet not usable at this level — expect ongoing blood loss and use tranexamic acid and staged haemostasis.
Mnemonic
SALVAGEPrerequisites for Offering Total Femur Replacement
S
Soft tissues
Closable, vascular envelope over the implant (plastics if not)
A
Ambulatory potential
Realistic goal of household/community walking with aids
L
Length planned
Contralateral femur templated before the native femur is removed
V
Vessels and nerves
Functioning femoral/sciatic nerves and adequate vascularity
A
Absence of active sepsis
Or a staged pathway with spacer and targeted antibiotics
G
Good extensor mechanism
Active knee extension preserved or reconstructable
E
Engaged patient
Motivation, cognition and physiologic reserve for salvage
Hook:Total femur replacement IS a SALVAGE operation — run the checklist before you offer it.
Mnemonic
TENSEIntraoperative Priorities
T
Trochanteric fragment
Preserve abductors on a bone wafer, cable to implant
E
Extensor mechanism
Never violate the patellar tendon or tibial tubercle
N
Nerve (sciatic)
Protect throughout; check tension after trialling length
S
Soft-tissue tension sets length
Not bony landmarks — the femur is gone
E
Envelope closure
Full muscle cover over the implant; mesh/tube augmentation
Hook:A total femur limb should be TENSE enough to be stable, never so tense it palsies the sciatic nerve.
Complications
Deep infection
- Approximate Rate / Context
- 20 to 30 percent in non-oncologic salvage series; around 10 percent in primary oncologic series — highest of any endoprosthesis
- Prevention and Management
- Staged surgery for infected cases, full soft-tissue cover, consider silver-coated implants; established infection usually needs debridement/exchange and frequently ends in disarticulation
Hip dislocation / instability
- Approximate Rate / Context
- Common with deficient abductors, historically 10 to 20 percent with conventional bearings
- Prevention and Management
- Dual mobility or constrained liner, abductor reattachment with mesh augmentation, abduction brace, precautions; recurrent instability → constrained revision
Extensor insufficiency / lag
- Approximate Rate / Context
- Related to prior surgery, arthrotomy handling, patellar tendon compromise
- Prevention and Management
- Protect tubercle; reconstruct with mesh/allograft if deficient; brace in extension; persistent lag markedly degrades function
Wound problems / dehiscence
- Approximate Rate / Context
- Frequent in multiply operated limbs; gateway to deep infection
- Prevention and Management
- Incorporate prior scars, plastics input, tension-free closure, low threshold for early washout and flap coverage
Nerve palsy (sciatic/peroneal)
- Approximate Rate / Context
- Traction injury with lengthening or posterior dissection
- Prevention and Management
- Limit lengthening, palpate nerve tension, flex knee postoperatively; most traction palsies recover partially
Mechanical failure
- Approximate Rate / Context
- Hinge wear, bearing exchange, aseptic loosening of tibial/acetabular fixation over time
- Prevention and Management
- Modular systems allow bearing/segment exchange without full revision
Mortality / medical
- Approximate Rate / Context
- Meaningful perioperative medical morbidity in elderly salvage cohorts (blood loss, long anaesthetic)
- Prevention and Management
- Selection, optimisation, cell salvage, HDU pathway
Failure has no bony fallback
When a total femur fails irretrievably — usually through uncontrolled infection — the salvage is hip disarticulation. This must feature in the original consent discussion, and it is why infection prevention (staging, coverage, coated implants) dominates the strategy.
Functional Outcomes and Comparison with Hip Disarticulation
Realistic counselling is an exam favourite:
- Ambulation: most patients achieve household to limited community walking, almost always with a stick, crutches or frame; abductor-deficient (Trendelenburg) gait is the norm.
- Function scores: mean MSTS scores in reported series typically fall around 60 to 70 percent — below distal or proximal femoral replacement, above disarticulation.
- Satisfaction: high in appropriately selected patients — the retained limb, preserved body image, ability to transfer and sit normally, and avoidance of prosthetic fitting drive this.
- Hip disarticulation comparison: disarticulation prostheses are heavy, energy-expensive (energy cost of walking rises dramatically compared with transfemoral levels) and abandoned by the majority of elderly amputees, who become wheelchair users. In selected patients, TFR gives superior function and quality of life; in the frail, persistently infected or bed-bound patient, disarticulation gives faster, more reliable wound resolution and palliation.
Limb
- Total Femur Replacement
- Retained, sensate limb; normal sitting and transfers
- Hip Disarticulation
- Limb lost; sitting balance and pressure areas affected
Walking
- Total Femur Replacement
- Household-community with aids in most
- Hip Disarticulation
- Majority of elderly patients never walk with a prosthesis
Infection risk
- Total Femur Replacement
- 20 to 30 percent, may still end in disarticulation
- Hip Disarticulation
- Definitive source control; wound problems still common
Reoperation burden
- Total Femur Replacement
- Ongoing lifetime revision/bearing exchange risk
- Hip Disarticulation
- Usually a single definitive procedure
Best suited to
- Total Femur Replacement
- Motivated patient, closable envelope, working extensor mechanism, controlled infection
- Hip Disarticulation
- Uncontrollable sepsis, non-functional limb, no reconstructive option, palliation
Guidelines, Registries & Global Practice
- Guidelines: no society issues a dedicated total-femur guideline; the operation sits within broader frameworks — MSTS/ISOLS principles for endoprosthetic limb salvage, international consensus (ICM Philadelphia) recommendations for periprosthetic infection staging, and generic revision-arthroplasty guidance (EFORT, AAOS revision pathways, national getting-it-right programmes) emphasising centralisation of complex salvage to specialist units.
- Registries: total femoral replacements are rare and inconsistently captured; national joint registries (NJR, AOANJRR, AJRR, SHAR, Norwegian, NZJR) record them within revision/tumour prosthesis categories, so the best outcome data remain single-centre and multicentre sarcoma-unit series rather than registry survivorship curves. Registry reports consistently show that mega-endoprosthetic revisions carry markedly higher re-revision and infection rates than conventional revision arthroplasty.
- Global practice variation: in high-resource systems, modular total femoral systems, silver coating and staged infection pathways are standard; in resource-limited settings, cost and implant availability mean hip disarticulation, resection arthroplasty or prolonged spacer retention remain common definitive strategies, and rehabilitation infrastructure (prosthetics, physiotherapy) strongly influences whether salvage or amputation serves the patient better.
- Centralisation: because case volume per surgeon is tiny, most systems concentrate total femoral reconstruction in sarcoma or complex revision units with plastic surgery, microbiology and HDU support co-located.
Controversies & Areas of Uncertainty
- Single-stage versus two-stage in infection: growing single-stage experience in specialist units challenges the two-stage default, but no comparative data exist at total-femur scale; selection criteria remain expert opinion.
- Retaining the devascularised femoral shell around the implant (biologic sleeve for soft-tissue attachment) versus complete excision — attachment and stability benefits against a theoretical sequestrum/infection risk; no controlled evidence.
- Constrained liner versus dual mobility: constraint gives the most reliable stability in absent abductors but transfers stress to cup fixation; the threshold for constraint is undefined.
- Silver and other antimicrobial coatings: supportive observational data, no randomised evidence, cost and availability limit uptake.
- Total femur versus disarticulation in the frail elderly: quality-of-life data favour salvage in selected patients, but selection bias in all series is profound; when reserve is marginal, honest equipoise remains.
- Compressive osseointegration and custom 3D-printed constructs for extreme bone loss short of true total femur — expanding the middle ground and shifting the threshold at which a total femur is chosen.
Evidence Base
Evidence
Total femur replacement in non-oncologic revision arthroplasty
Berend, Lombardi et al. • Journal of Arthroplasty / related salvage series (2004)
Finding: Total femoral arthroplasty for massive bone loss after failed hip and knee arthroplasty achieved limb salvage and ambulation in most patients, but with high complication rates dominated by infection and instability.
Clinical implication: Established TFR as a viable alternative to disarticulation in the failed-arthroplasty cascade while defining its high-risk profile — quote it as the archetypal non-oncologic salvage series.
Evidence
Oncologic total femoral endoprosthetic reconstruction
Multiple sarcoma-centre series (including Royal Orthopaedic Hospital Birmingham and Royal National Orthopaedic Hospital Stanmore cohorts) • JBJS Br / Bone and Joint Journal / Clin Orthop (1990s-2010s)
Finding: Total femoral replacement after sarcoma resection provides durable limb salvage with mean MSTS function around two-thirds of normal; infection around 10 percent in primary oncologic settings, higher in revision settings, with infection the leading cause of amputation.
Clinical implication: Provides the benchmark outcome and infection figures for primary versus salvage indications.
Evidence
Silver-coated megaprostheses and infection
Hardes et al. • Journal of Surgical Oncology (2010)
Finding: Silver-coated tumour endoprostheses were associated with a lower periprosthetic infection rate than uncoated titanium implants without evidence of systemic silver toxicity.
Clinical implication: Supports selective use of antimicrobial implant surfaces in the highest-infection-risk endoprosthetic population — total femur patients are the prime candidates.
Evidence
Energy cost of amputee gait
Waters et al. • JBJS Am (1976)
Finding: Energy expenditure of walking rises progressively with more proximal amputation levels; hip-level amputees have the highest energy cost, and many elderly patients cannot sustain prosthetic ambulation.
Clinical implication: The physiological argument for limb salvage over hip disarticulation in patients with borderline cardiopulmonary reserve.