Reconstructing the failed primary hip — component extraction, bone-defect management by Paprosky type, and a stability-first revision.
- Aseptic loosening is the commonest reason (30–40 percent of revisions): progressive start-up or activity-related pain with radiographic loosening — progressive radiolucent lines greater than 2 mm, component migration greater than 5 mm, subsidence, osteolysis, or a change in position on serial films.
- Exclude infection before every aseptic revision (periprosthetic joint infection drives 15–20 percent). Apply the 2018 ICM/MSIS weighted criteria: serum ESR greater than 30 mm/hr or CRP greater than 10 mg/L prompts aspiration; synovial WBC greater than 3000 or PMN greater than 80 percent, positive alpha-defensin or culture support the diagnosis.
- Classify bone loss on both sides — Paprosky acetabular (Type I intact rim to Type IIIB with Kohler line violated and possible pelvic discontinuity) and Paprosky femoral (Type I minimal metaphyseal loss to Type IV massive loss). The grade dictates the implant, from a standard cup/stem through augments and cup-cage to a proximal femoral replacement.
- The extended trochanteric osteotomy (ETO) is the workhorse for a well-fixed stem: a controlled anterolateral one-third-circumference cut extending 1–2 cm past the stem tip, the vastus lateralis sleeve preserved, fixed with three to four cerclage cables. It converts an uncontrolled-fracture scenario (20–30 percent) into a predictable one (under 5 percent) and heals in over 95 percent.
- Acetabular reconstruction aims for at least 50–70 percent host-bone contact and an anatomical hip centre, with defects managed by type — cavitary loss with particulate graft, segmental loss with metal augments or structural allograft.
- Femoral revision bypasses the deficient metaphysis to gain 4–6 cm of diaphyseal scratch-fit (extensively coated stems) or uses a modular tapered stem where isthmic stock is short.
- Stability is the hardest part of a revision — restore offset and hip centre, use large heads (36–40 mm), and reach for dual mobility in high-risk reconstructions, which cuts re-dislocation from 10–15 percent to 1–3 percent.
When & Why
The five reasons a primary hip fails — in roughly this order of frequency: - Aseptic loosening (30–40 percent) — progressive start-up or activity-related groin/thigh pain with radiographic loosening: progressive radiolucent lines greater than 2 mm, component migration greater than 5 mm, subsidence, osteolysis, or a change in position on serial films; symptomatic with functional limitation or impending fracture from bone loss.
- Periprosthetic joint infection (15–20 percent) — diagnosed by the 2018 ICM/MSIS weighted criteria (below).
- Recurrent dislocation (20–25 percent) — two or more dislocations despite closed reduction, an abduction brace and physiotherapy, with an identifiable cause (component malposition, impingement, soft-tissue deficiency) that needs surgical correction.
- Periprosthetic fracture (10–15 percent) — Vancouver B2 (fracture around a loose stem) or B3 (loose stem with poor bone stock), or an acetabular fracture with component displacement, where stable fixation cannot be regained without revision.
- Osteolysis and wear (10–15 percent) — progressive debris-driven bone loss, expanding osteolytic lesions threatening component stability, impending pathological fracture, or symptomatic metallosis from metal-on-metal failures. Exclude infection before every revision. Serum ESR and CRP are the first screen (elevated in about 90 percent of infections). Aspirate the hip if ESR is greater than 30 mm/hr, CRP is greater than 10 mg/L, or there is any clinical suspicion — hold antibiotics for a minimum of two weeks first. Send synovial fluid for cell count and differential (WBC greater than 3000 or PMN greater than 80 percent is highly suggestive), culture and sensitivity, and alpha-defensin or leukocyte esterase if available. Expect a false-negative aspiration in 10–15 percent; if suspicion remains high, plan intraoperative frozen section. The 2018 ICM/MSIS weighted score then frames the decision: two positive cultures of the same organism, or a sinus tract, are major (diagnostic) criteria; an aggregate score of 6 or more is infected, 2–5 is inconclusive (add intraoperative histology, purulence or a single positive culture), and 0–1 is not infected. Imaging. AP pelvis and lateral hip (both hips for comparison), Judet views (obturator and iliac oblique) for the acetabular columns, and full-length femur films for canal geometry and bone loss. A CT with three-dimensional reconstruction quantifies severe bone loss, aids custom-implant planning and helps confirm pelvic discontinuity; metal-artifact-reduction sequence (MARS) MRI assesses soft-tissue destruction where needed. Classify the bone loss — it drives everything. Assign a Paprosky acetabular grade (Type I intact rim to Type IIIB with Kohler line violated) and a Paprosky femoral grade (Type I minimal metaphyseal loss to Type IV massive loss) — the full tables are in Background & Evidence. Match implants to the grade (standard cup/stem through jumbo cups and augments to cup-cage or triflange and proximal femoral replacement), and have extended sizes, graft, augments, cages and ETO instruments on the shelf before you start. Optimise the patient. A revision is longer and more physiologically demanding than a primary. Correct anaemia (iron or erythropoietin if Hb less than 120 g/L), nutrition (albumin greater than 35 g/L, lymphocytes greater than 1.5), glycaemia (HbA1c under 7 percent in diabetes) and insist on smoking cessation at least six weeks preoperatively. Plan cardiac and respiratory optimisation and a VTE risk assessment (previous VTE, thrombophilia or malignancy may need extended prophylaxis).
The Operation
The goal is to remove the failed components without creating new bone loss, reconstruct the acetabulum and femur to their anatomical centres, and rebuild a stable hip. The posterior approach through the previous scar is the global workhorse (laid out in depth on the posterior (Moore/Southern) approach page); the extended trochanteric osteotomy is the extensile move that turns a dangerous extraction into a controlled one. The sequence below lays out exposure and ETO first, then extraction, defect-based reconstruction, stability testing and closure.
Operative sequence
- Standard lateral decubitus, operative side up; pelvis perpendicular to the floor, supported at the ASIS anteriorly and the sacrum posteriorly; pad every bony prominence (fibular head, malleoli, contralateral trochanter).
- Prep and drape widely — mid-thorax to knee — so the incision can extend proximally for the acetabulum and distally for the femur or an ETO.
- Use the previous posterior incision where possible (the most lateral scar has the best blood supply when several exist); an extended length of 20–30 cm is typical versus 15–20 cm for a primary.
- Excise the old scar in full (send for histology to exclude malignancy). The planes are often obliterated by scar; dissect sharply and bluntly onto the greater trochanter, the key landmark, and the gluteus maximus fascia.
- Split gluteus maximus in line with its fibres; the short external rotators may be scarred, attenuated or absent — tag any repairable tissue for later re-attachment (stability insurance).
- Identify the sciatic nerve early at the inferior border of piriformis if anatomy allows; it may be scarred or displaced by a prior leg-length change. Protect it throughout with retractors under direct vision, keep the hip flexed to slacken it, and limit retraction time.
- Flex, adduct and internally rotate (posterior approach). Dislocation may be difficult with well-fixed components, heterotopic ossification or dense scar.
- Do not force it — osteoporotic bone fractures easily. Instead excise heterotopic bone (send for pathology), release the anterior capsule and iliopsoas, remove a modular head with a universal head remover, or proceed to an ETO if exposure remains inadequate.
- Once dislocated, clear the rim and screw holes of soft tissue and ingrowth and test cup stability with the rotation test (stable if it will not rotate, loose if it spins).
Indicated for a well-fixed uncemented (especially fully-coated) or cemented stem, to bypass a proximal fracture or defect, to correct stem version, or to visualise the distal canal for cement removal.
- Mark the anterolateral femur from the vastus ridge to 1–2 cm past the stem tip; the fragment is one-third of the circumference (too thin fractures, too thick will not reflect).
- Perforate the lateral cortex at intervals with a 3.2 mm drill (controlled stress risers), complete the longitudinal cuts with an oscillating saw, and gently lever the fragment open on its anterolateral soft-tissue hinge — preserve the gluteus medius–trochanter–vastus lateralis sleeve, the blood supply for healing.
- The stem now mobilises easily from distal to proximal and the cement is removed under direct vision. Fixation later: a minimum of three (ideally four to six) cerclage cables 1–2 cm apart, or a plate if the fragment is comminuted; touch-down weight-bearing for six weeks.
- Loose cup: pass curved osteotomes at three to four points around the rim, attach an explantation device and extract with a slap hammer or threaded extractor — it should come without force.
- Well-fixed cup: thin curved osteotomes work the bone–implant interface circumferentially and gradually (avoid an acetabular fracture); remove screws, drilling out overgrown heads if needed. Keep osteotomes along the rim and never lever against the intrapelvic cortex.
- If a well-fixed cup is well-positioned, cementing a new liner inside it (cup-in-cup) avoids a destructive extraction.
- Loose cemented stem: clear the proximal stem–cement interface, attach an extractor, withdraw with controlled force.
- Well-fixed cemented stem: window the proximal mantle, divide the stem–cement bond with flexible osteotomes, or — safest — perform the ETO first.
- Loose uncemented stem: clear proximal ingrowth, attach a threaded extractor or slap hammer, withdraw.
- Well-fixed uncemented (especially fully-coated) stem: ETO first — uncontrolled fracture runs 20–30 percent without an ETO versus under 5 percent with one — then extract from distal to proximal.
- Split the proximal mantle radially with osteotomes, fragment it and remove with rongeurs and curettes.
- Locate the distal plug on the preoperative films (measure from the lesser trochanter), drill through it and retrieve fragments with reverse hooks and curettes working from distal to proximal.
- A high-speed burr frees adherent cement under continuous irrigation; an ultrasonic device shifts stubborn segments. Finish with copious pulsed lavage, flexible reamers to a bleeding bed, and inspect the distal canal with a headlight and fibreoptic light.
- Expose the whole acetabulum circumferentially, clear all fibrous tissue, and palpate the columns, superior and medial rim. Confirm or exclude pelvic discontinuity (motion on manual stress; a step at the ilioischial line on imaging).
- Type I or IIA — ream to bleeding bone and press-fit a hemispheric cup 1–2 mm larger than the last reamer (target 70 percent host-bone contact), with two to three screws if needed. Survival about 95 percent at 10 years.
- Type IIB or IIC — jumbo cup or high hip centre (under 2 cm superior migration), or a superior tantalum/titanium augment; a medial-wall deficiency is grafted with morselised allograft behind mesh.
- Type IIIA (severe loss, Kohler intact) — jumbo cup with a superior augment, or trabecular-metal augments. Survival 85–90 percent at 10 years.
- Type IIIB (Kohler violated, possible discontinuity) — antiprotrusio cup-cage spanning ilium to ischium with multiple screws and a cemented cup inside in correct orientation with dual mobility; or a custom triflange. Survival 80–85 percent at 10 years. Restore pelvic-ring continuity (posterior column plate) if discontinuous.
- Palpate the cortices circumferentially; separate segmental (missing wall) from cavitary (enlarged canal) loss and measure the intact diaphysis from the lesser trochanter distally.
- Type I — standard uncemented stem with 4–6 cm diaphyseal engagement (about 95 percent survival at 10 years).
- Type II — extensively porous-coated cylindrical stem (8–10 in.) bypassing the deficient metaphysis, or a modular tapered stem (90–95 percent survival at 10 years).
- Type IIIA — long extensively coated stem (10–12 in.) with onlay cortical strut allografts for segmental loss (two to four struts, 8–10 cm overlap, cerclage) and particulate graft for cavitary loss (85–90 percent survival).
- Type IIIB — impaction bone grafting (Ling technique) with a cemented polished stem, or a modular tapered stem maximising diaphyseal contact despite short isthmic stock (75–85 percent survival).
- Type IV — proximal femoral replacement (megaprosthesis) or an allograft-prosthesis composite, with dual mobility or a constrained liner for the high dislocation risk (70–80 percent survival).
- With trial liners and multiple neck lengths, reduce and test: flexion 110° with internal rotation 70–90° (posterior stability) and extension 30° with external rotation 45° (anterior).
- Shuck test: 5–10 mm translation is ideal; greater than 15 mm is too loose, and none at all is too tight (risks fracture on impaction).
- Restore offset and leg length (measure from the ASIS to a fixed femoral landmark; each 5 mm of lost offset cuts the abductor moment arm by about 15 percent). Check the sciatic nerve is slack — lengthening greater than 4 cm threatens the nerve, which cannot stretch more than 6 percent.
- Seat the acetabular component to match the trial (360° rim contact, liner locked and checked); for cage constructs, secure the cage with iliac and ischial screws before cementing the cup in orientation.
- Insert the femoral stem at the templated version and depth (uncemented) or with standard cement technique (distal plug, retrograde fill, pressurise, hold through polymerisation); assemble modular tapers clean and dry.
- Reduce the ETO fragment anatomically and fix it with cables 1–2 cm apart (or a plate if comminuted). Lay cortical struts bridging segmental defects with 8–10 cm overlap, cabled at each end.
- Copious irrigation — 6–9 litres (a longer, higher-contamination case than a primary).
- Re-attach the short external rotators through bone tunnels where repairable; if absent, rely on implant stability (large head, dual mobility, constrained liner).
- A deep drain is more often used in revision for the larger dead space (expect 200–600 mL over 24–48 h; remove below 50 mL per 8 h). Layered closure and an abduction pillow.
The external iliac vessels, ureter, bladder and rectum lie just inside the cortex and are injured if an osteotome is levered against the intrapelvic wall. Direct osteotomes along the component rim, advance incrementally, and never lever on the cortex. Acetabular fracture during extraction occurs in 3–5 percent — a small crack (under 2 cm) is managed with screws and the case proceeds; a large fracture or column injury needs plate fixation first and may force abandonment of the revision.
Cortical perforation (5–10 percent) follows thin cortices, osteoporosis and aggressive burring; a small perforation (under 1 cm) is bypassed by a stem extending two cortical diameters past it, a large one (over 1 cm) needs a cortical strut or plate. Femoral fracture (2–5 percent) is prevented by the cement-splitting technique — longitudinal osteotomes fracturing the mantle rather than burring through it — and by patience.
A well-fixed fully-coated stem almost always needs an ETO: extraction force tracks with coating extent, and an 8–10 in. fully-coated stem has such extensive ingrowth that forcing it fractures the femur in 20–30 percent of cases. If reasonable osteotome dissection does not mobilise the stem, stop and perform the ETO rather than force it — that converts a catastrophic spiral fracture into a controlled, reliably healing osteotomy (union over 95 percent).
Place screws in the posteroinferior quadrant (3–5 o'clock right hip, 7–9 o'clock left hip, below the transverse acetabular ligament) and the posterosuperior quadrant (10–11 o'clock right, 1–2 o'clock left, directed posteriorly). Avoid the anterosuperior quadrant, where the external iliac vessels lie, and limit screw length to 20–25 mm — closer still to the cortex when bone loss has drawn the vessels in.
You cannot read stability from a radiograph. Test with trials through a full arc; if unstable, fix it before implanting — larger head (36–40 mm), then dual mobility (effective head 52–56 mm, which drops re-dislocation from 15–20 percent to 1–3 percent), then a constrained liner only as a last resort. Never implant final components hoping stability will appear.
Aftercare & Complications
Weight-bearing and precautions | Phase | Timing | Weight-bearing | Precautions and therapy | |-------|--------|----------------|-------------------------| | 1 | 0–6 weeks | Touch-down (10–20 kg) if an ETO or cortical struts were used; WBAT if a standard uncemented reconstruction without ETO or struts | Abduction pillow; no flexion past 90°, no adduction past midline, no internal rotation in flexion | | 2 | 6–12 weeks | Advance to WBAT if radiographic healing; full weight-bearing by 12 weeks once union | Progressive range of motion, abductor strengthening (many have preoperative weakness) | | 3 | 3–12 months | Full | Graded return — desk work around 3 months, heavy manual around 6 months; improvement continues to 12–24 months | Hip precautions run 12 weeks (extended versus 6 weeks for a primary) because of soft-tissue deficiency. VTE prophylaxis: LMWH (enoxaparin 40 mg SC daily) or a DOAC (rivaroxaban 10 mg daily, apixaban 2.5 mg twice daily) for 35 days, started 12–24 h postoperatively, with TED stockings and intermittent pneumatic compression until mobile. Radiographic surveillance at 6 weeks (position, ETO or strut healing), 3 months (union), 6 months, 1 year, then annually — registry-aligned long-term follow-up (NJR, AJRR, AOANJRR, SHAR). A deep drain is removed at 24–48 h once output drops below 50 mL per 8 h. Complications — recognition, prevention, management
- Recognition
- Fever, wound drainage, erythema, pain. ESR greater than 30 or CRP greater than 10 (elevated in about 90 percent); aspiration WBC greater than 3000 or PMN greater than 80 percent, positive culture. Apply the 2018 ICM/MSIS criteria.
- Prevention
- Cefazolin 2 g IV within 60 min (redose over 4 h or high blood loss; add vancomycin or teicoplanin where MRSA warrants), minimise operative time, meticulous haemostasis, albumin greater than 35 g/L, HbA1c under 7 percent, smoking cessation 6+ weeks, chlorhexidine prep, theatre discipline.
- Management
- Acute (under 3 weeks): DAIR with exchange of modular parts plus 6 weeks IV then lifelong suppression (50–70 percent success). Chronic: two-stage revision — explant, debridement, spacer, 6 weeks IV, reimplant when markers normalise (85–95 percent success). Salvage: resection arthroplasty, arthrodesis, amputation.
- Recognition
- Acute pain, leg shortened and internally rotated (posterior) or externally rotated (anterior); AP pelvis shows head–cup incongruence.
- Prevention
- Restore hip centre and offset, large heads (36–40 mm), dual mobility for high risk (prior dislocation, abductor deficiency) reducing to 1–3 percent, Lewinnek safe-zone position, soft-tissue repair, 12-week precautions, abduction brace if very high risk.
- Management
- First: closed reduction, CT for cause, 12-week precautions or brace; revise if malposition. Recurrent (two or more): revision to dual mobility (most common), correct malposition, upsize head, increase offset, constrained liner if dual mobility fails.
- Recognition
- Foot drop, lateral leg or foot numbness; document the exam immediately to distinguish injury from regional block wearing off. EMG or NCS at 3 weeks.
- Prevention
- Identify early at the inferior piriformis border, retractors under vision, hip flexed, avoid lengthening over 4 cm, gentle scar dissection, palpate after reduction.
- Management
- Document immediately (medicolegal). If under tension intraoperatively, shorten (shorter neck or reseat the stem). EMG at 3 weeks, AFO for foot drop, physiotherapy; about 80 percent recover by 1 year. Explore only for a complete immediate deficit.
- Recognition
- Crack or loss of resistance on extraction or insertion, visible fracture line; confirm with AP and lateral.
- Prevention
- Plan an ETO for well-fixed stems, gentle incremental extraction (no force), prophylactic cables for thin cortex.
- Management
- Acetabular: small crack (under 2 cm) add screws and proceed; large or column fracture plate first. Femoral (Vancouver): AG or AL cable if displaced; B1 cables then proceed; B2 longer stem bypassing two cortical diameters plus struts; B3 impaction grafting or long stem or proximal femoral replacement; C plate. Extend an ETO past a B-fracture apex.
- Recognition
- Progressive start-up pain; progressive radiolucent lines greater than 2 mm, migration greater than 5 mm, subsidence, osteolysis, change in position versus the immediate post-op films.
- Prevention
- Biological ingrowth with 50–70 percent host contact (uncemented in younger patients; cemented acceptable in elderly low-demand), anatomical biomechanics, proven implants, defect-appropriate graft, bone-health optimisation.
- Management
- Observe asymptomatic progressive radiolucency with 6-monthly films and revise before major bone loss. Symptomatic: re-revision (more bone loss, more scar, worse outcomes — satisfaction 60–70 percent versus 75–85 percent first time; re-re-revision 15–25 percent at 5 years). Counsel: salvage, not restoration.
- Recognition
- Patient reports a longer or shorter leg, limp, back pain; measure ASIS to medial malleolus, assess pelvic obliquity with blocks; confirm on AP pelvis from lesser trochanter to joint line.
- Prevention
- Preoperative measurement and documented consent (may not equalise if severe bone loss); intraoperative offset guide and fixed-landmark measurement; restore anatomical centre; accept 5–10 mm lengthening if needed for stability.
- Management
- Under 10 mm: adapt over 3–6 months with gait physiotherapy. 10–20 mm: shoe lift. Over 20 mm or intolerant: consider revision (head or neck exchange 5–10 mm, stem re-seating, cup repositioning) weighing risk — prevention and consent beat treatment.
- Recognition
- Nonunion: mobile fragment, persistent lateral thigh pain, radiolucent line beyond 6 months without bridging. Malunion: prominence with iliotibial-band irritation.
- Prevention
- Preserve the vastus lateralis sleeve, one-third-circumference cut extending past the tip, rigid fixation (three to four cables or a plate), anatomical reduction, touch-down for 6 weeks.
- Management
- Asymptomatic: observe. Symptomatic nonunion: revision fixation with plate, cables and graft. Symptomatic malunion: takedown and reposition. Union exceeds 95 percent with rigid fixation and good soft tissue.
Viva & Exam Focus
REVISEREVISE — preoperative assessment
DEFECTSDEFECTS — acetabular defect management
Location: exits below piriformis, 2–3 cm medial to the trochanter tip, often scarred or displaced in revision. Protection: identify early at the inferior piriformis border, retractors under direct vision, keep the hip flexed, gentle scar dissection, avoid lengthening over 4 cm, palpate after reduction.
Location: exits the greater sciatic notch above piriformis, 25–40 mm above the trochanter tip between gluteus medius and minimus. Protection: limit superior dissection to under 4 cm above the tip, place superior retractors under direct vision over the rim rather than into muscle.
Location: 30–50 mm medial and anterior to the acetabulum along iliopsoas (nerve lateral, vessels medial). Protection: anterior retractors over the rim under direct vision, gentle capsular release, beware distorted anatomy from bone loss.
Location: 20–30 mm from the anterosuperior rim, 15–20 mm from the posterosuperior rim, closer with superior or medial migration. Protection: screws only in posteroinferior (3–5 or 7–9 o'clock) and posterosuperior (10–11 or 1–2 o'clock) zones, length 20–25 mm; osteotomes along the rim, never the intrapelvic cortex.
Location: through the obturator foramen 10–20 mm inferomedial to the acetabulum. Protection: no inferomedial screws, recognise medial-wall perforation as a sudden loss of resistance on reaming.
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
“A 68-year-old woman has progressive groin pain 8 years after a primary THR, with progressive acetabular radiolucent lines and 3 cm of superior cup migration. How do you assess and manage her?”
“You are revising an aseptically loose but well-fixed cemented femoral stem with a narrow distal canal and cannot extract it. What are your options?”
“Describe your management of a Paprosky Type IIIB acetabular defect in a 72-year-old with severe superior and medial migration, a violated Kohler line and suspected pelvic discontinuity.”
Indications (know the frequencies)
- Aseptic loosening 30–40 percent — progressive pain, radiolucent lines greater than 2 mm, migration greater than 5 mm, subsidence, osteolysis
- PJI 15–20 percent — 2018 ICM or MSIS: ESR greater than 30 or CRP greater than 10, synovial WBC greater than 3000 or PMN greater than 80 percent, positive culture
- Recurrent dislocation 20–25 percent — two or more despite conservative care
- Periprosthetic fracture 10–15 percent — Vancouver B2 or B3 (loose stem)
- Osteolysis and wear 10–15 percent — debris bone loss, metallosis
Danger structures
- Sciatic nerve — below piriformis, 2–3 cm medial to the tip; identify early, hip flexed, no lengthening over 4 cm
- Superior gluteal — above piriformis, 25–40 mm above the tip; dissection under 4 cm above the tip
- Femoral neurovascular bundle — 30–50 mm anteromedial; anterior retractors over the rim under vision
- External iliac (intrapelvic) — screws in posteroinferior (3–5 or 7–9) and posterosuperior (10–11 or 1–2) zones, 20–25 mm
- Obturator — no inferomedial screws; watch for medial-wall perforation
Critical sequence
- Exclude infection, then classify (Paprosky acetabular I to IIIB, femoral I to IV), template, have the kit
- Previous posterior scar, extended 20–30 cm, protect the sciatic nerve
- Dislocate gently (never force); ETO for a well-fixed stem (fracture 20–30 percent drops to under 5 percent)
- Extract cup and stem; remove cement to a bleeding bed
- Reconstruct by Paprosky type; test stability before committing; fix the ETO and struts; close over a drain
Reconstruction by grade (10-year survival)
- Acetabular I or IIA — standard cup plus screws, about 95 percent
- Acetabular IIB or IIC — jumbo cup or augment plus graft
- Acetabular IIIA — augment or jumbo plus augment, 85–90 percent
- Acetabular IIIB — cup-cage or triflange, 80–85 percent
- Femoral I 95 percent; II extensively coated or modular 90–95 percent; IIIA long stem plus struts 85–90 percent; IIIB impaction grafting or modular 75–85 percent; IV megaprosthesis or APC 70–80 percent
Stability and complications
- Restore offset and centre; large heads 36–40 mm; dual mobility for high risk (15–20 percent drops to 1–3 percent)
- PJI 2–4 percent — acute DAIR 50–70 percent, chronic two-stage 85–95 percent
- Dislocation 5–10 percent; sciatic injury 1–2 percent transient; intraoperative fracture 5–10 percent
- Re-revision is worse — satisfaction 60–70 percent; counsel that it is salvage, not restoration
Post-op protocol
- Touch-down 6 weeks if ETO or struts (WBAT if a standard reconstruction); full by 12 weeks
- Precautions 12 weeks (extended); VTE prophylaxis 35 days
- Radiographs 6 weeks, 3 months, 6 months, 1 year, then annually (registry-aligned)
Background & Evidence
Epidemiology. Revision burden — the proportion of arthroplasties that are revisions — sits around 10–15 percent of all hip procedures in the major registries and rises with time from the primary. The AOANJRR reports a cumulative revision rate for revision THR of about 14.8 percent at 10 years, and the NJR, AJRR and SHAR consistently show revision THR carries a several-fold higher re-revision risk than a primary at every interval. Aseptic loosening and instability are the dominant failure modes worldwide; the share attributed to infection has risen with better detection (the 2018 ICM/MSIS criteria). Why hips fail — pathoanatomy. Aseptic loosening is driven by particulate debris (polyethylene, metal) generating a macrophage-mediated osteolytic cascade that erodes the bone–implant interface; mechanical factors (off-axis loading, impingement, micro-motion) accelerate it. Instability follows component malposition, impingement, abductor deficiency or soft-tissue destruction. Osteolysis may be silent until a pathological fracture. Each failure mode leaves a characteristic bone-defect pattern that the Paprosky systems grade.
- Defining features
- Intact rim, minimal lysis; over 50 percent host contact achievable
- Reconstruction (10-year survival)
- Standard uncemented cup plus screws (about 95 percent)
- Defining features
- Intact columns, superior loss, under 2 cm migration
- Reconstruction (10-year survival)
- Standard cup plus screws (about 95 percent)
- Defining features
- Superior or lateral loss, some medial migration, transverse acetabular ligament preserved
- Reconstruction (10-year survival)
- Jumbo cup or high hip centre; superior augment
- Defining features
- Medial-wall deficiency, medial migration, columns intact
- Reconstruction (10-year survival)
- Morselised graft behind mesh plus standard cup
- Defining features
- Severe loss, 2–3 cm migration, Kohler line intact
- Reconstruction (10-year survival)
- Jumbo cup plus augment, or trabecular-metal augment (85–90 percent)
- Defining features
- Severe loss, Kohler line violated (medial wall absent), pelvic discontinuity possible
- Reconstruction (10-year survival)
- Cup-cage or custom triflange (80–85 percent)
- Defining features
- Minimal metaphyseal loss, intact diaphysis, good cancellous bone
- Reconstruction (10-year survival)
- Standard uncemented stem (about 95 percent)
- Defining features
- Extensive metaphyseal loss, intact diaphysis over 4 cm
- Reconstruction (10-year survival)
- Extensively coated cylindrical stem or modular tapered (90–95 percent)
- Defining features
- Metadiaphyseal loss, over 4 cm of intact isthmus
- Reconstruction (10-year survival)
- Long extensively coated stem 10–12 in. plus cortical struts (85–90 percent)
- Defining features
- Under 4 cm of intact isthmus, widened canal
- Reconstruction (10-year survival)
- Impaction grafting (Ling) or modular tapered stem (75–85 percent)
- Defining features
- Extensive metadiaphyseal loss, widened canal, little cortical support
- Reconstruction (10-year survival)
- Proximal femoral replacement or allograft-prosthesis composite (70–80 percent)
Key evidence. The Paprosky acetabular classification (Paprosky 1994) and femoral classification (Della Valle and Paprosky 2004) remain the global reference frameworks, linking defect pattern to reconstruction strategy and failure risk. The extended trochanteric osteotomy (Younger 1995) is the workhorse extensile exposure, converting a high-risk uncontrolled-fracture scenario into a controlled, reliably healing osteotomy. Infection must be excluded before any aseptic revision; the 2018 ICM/MSIS weighted criteria (Parvizi 2018) are the validated international standard, with higher sensitivity than the earlier 2011 MSIS and 2013 ICM definitions. For stability, dual-mobility bearings substantially reduce instability after revision (Sephton 2025) and are preferred for high-risk reconstructions, though a large femoral head may offer comparable stability when soft tissues permit. Long-term performance is tracked by the national registries (NJR, AJRR, AOANJRR, SHAR), which consistently show revision THR carrying a several-fold higher re-revision risk than primary.
References
Acetabular defect classification and surgical reconstruction in revision arthroplasty: a 6-year follow-up evaluation
- 147 acetabular components revised with cementless hemispheric press-fit components, mean follow-up 5.7 years (range 3-9 years)
- Defined the Paprosky acetabular classification (Type 1 to Type 3B) based on superior/medial migration, rim and column integrity, and ischial/teardrop lysis
- Only 6 of 147 cups (4.0%) were unstable warranting re-revision - all were Type 3B defects, confirming that severe defects carry the worst prognosis
- Adequate remaining host bone contact is essential for bony ingrowth of the cementless cup
The femur in revision total hip arthroplasty evaluation and classification
- Presented the Paprosky femoral bone-loss classification (Type I to Type IV) based on metaphyseal cancellous loss, diaphyseal integrity and length of supportive isthmus
- Type I-II have supportive diaphysis suitable for extensively coated or tapered diaphyseal-fixation stems
- Type IIIB (less than 4cm of intact isthmus) and Type IV (non-supportive widened canal) require modular tapered stems, impaction grafting, allograft-prosthesis composite or proximal femoral replacement
- Preoperative classification ensures the correct implants and instruments are available, reducing intraoperative compromise
Extended proximal femoral osteotomy: a new technique for femoral revision arthroplasty
- Described the extended trochanteric osteotomy (ETO): anterolateral one-third-circumference cut levered open on an anterolateral periosteal/muscle hinge, preserving the gluteus medius-trochanter-vastus lateralis sleeve
- Provides wide access to ingrowth surfaces and distal cement, allows safe canal machining under direct vision and eliminates inadvertent varus stem placement
- Repaired with cerclage wires/cables; reliable healing reported in the first 20 patients with no change to the postoperative regimen
- Protects a weakened trochanter from iatrogenic fracture during difficult extraction
The 2018 definition of periprosthetic hip and knee infection: an evidence-based and validated criteria
- Multi-institutional study deriving a weighted PJI scoring system from 684 infected and 820 aseptic revision cases, externally validated on a further 422 patients
- Two positive cultures or a sinus tract are major (diagnostic) criteria; serum CRP, D-dimer, ESR and synovial markers (WBC, PMN%, alpha-defensin, leukocyte esterase, synovial CRP) carry weighted points
- Aggregate score 6 or more = infected, 2-5 = inconclusive (use intraoperative findings), 0-1 = not infected
- Higher sensitivity (97.7%) than the 2011 MSIS (79.3%) and 2013 ICM (86.9%) definitions with comparable specificity (99.5%)
Outcomes of dual mobility versus fixed-bearing components in revision total hip arthroplasty: a systematic review and meta-analysis
- Meta-analysis of 13 studies and 5,004 revision THA hips (2,108 dual mobility, 2,896 fixed bearing)
- Dual mobility had significantly lower odds of re-revision for dislocation (OR 0.38, p less than 0.001), aseptic loosening (OR 0.54, p = 0.004) and all-cause re-revision (OR 0.55, p less than 0.001)
- No significant difference in re-revision for infection or periprosthetic fracture between bearings
- On subgroup analysis, dual mobility showed no significant advantage over large (greater than 36mm) fixed-bearing heads for re-dislocation (OR 0.69, p = 0.11)