Summary THA Revision is most commonly performed to address aseptic loosening, fracture, instability, or infection associated with a prior THA. Diagnosis and etiology of THA failure can be determined by a combination of physical examination, labs, and hip radiographs. Treatment depends on etiology of failure, prior surgery and patient activity demands. Epidemiology Incidence in the United States is projected to increase >100% by 2030 Demographics roughly equal male to female average age of roughly 65-70 in most studies Etiology Pathophysiology femoral component failure acetabular component failure both component failure neither Indications wound healing complications periprosthetic fracture implant fracture hip instability periprosethic joint infection (PJI) adverse local soft tissue reaction (MoM) trunnionosis osteolysis aseptic loosening limb length discrepancy (LLD) Broad categories revision surgery without affecting modular OR nonmodular components revision wound closure psoas release heterotopic bone excision ORIF of periprosthetic fracture revision surgery affecting modular components only femoral head and or polyethyelene exchange titanium sleeve revision surgery nonmodular components acetabular component exchange most common reason for revision in the Charnley "low-friction" total hip arthroplasty femoral component exchange removal of both components replaced with new components replaced with antibiotic spacer girdlestone Classification of Bone Loss Acetabulum AAOS Classification of Acetabular Bone Loss Type I (segmental) Loss of part of the acetabular rim or medial wall Type II (cavitary) Volumetric loss in the bony substance of the acetabular cavity Type III (combined deficiency) Combination of segmental bone loss and cavitary deficiency Type IV (pelvic discontinuity) Complete separation between the superior and inferior acetabulum Type V (arthrodesis) Arthrodesis Paprosky Classification of Acetabular Bone Loss Type I Minimal deformity, intact rim Type IIA Superior bone lysis with intact superior rim Type IIB Absent superior rim, superolateral migration Type IIC Localized destruction of medial wall Type IIIA Bone loss from 10am-2pm around rim, superolateral cup migration Type IIIB Bone loss from 9am-5pm around rim, superomedial cup migration Femur AAOS Classification of Femoral Bone Loss Type I (segmental) Loss of bone of the supporting shell of femur Type II (cavitary) Loss of endosteal bone with intact cortical shell Type III (combined) Combination of segmental bone loss and cavitary deficiency Type IV (malalignment) Loss of normal femoral geometry due to prior surgery, trauma, or disease Type V (stenosis) Obliteration of the canal due to trauma, fixation devices, or bony hypertrophy Type VI (femoral discontinuity) Loss of femoral integrity from fracture or nonunion Paprosky Classification of Femoral Bone Loss Type I Minimal metaphyseal bone loss Type II Extensive metaphyseal bone loss with intact diaphysis Type IIIA Extensive metadiaphyseal bone loss, minimum of 4 cm of intact cortical bone in the diaphysis Type IIIB Extensive metadiaphyseal bone loss, less than 4 cm of intact cortical bone in the diaphysis Type IV Extensive metadiaphyseal bone loss and a nonsupportive diaphysis Presentation Symptoms groin pain --> acetabulum thigh pain --> femoral stem start-up pain --> component loosening night pain --> infection no improvement in pain after surgery --> incorrect diagnosis Physical exam inspection assess wound for infection gait external rotation of the affected extremity present with femoral stem subsidence femoral stems most commonly subside in retroversion range of motion in flexion, extension, abduction looking for restriction of motion or pain avoid positions of dislocation based on THA approach provocative test pain with resisted hip flexion suggests psoas impingement Imaging Radiographs recommended views AP pelvis orthogonal views of involved hip full-length femur radiographs opitional views pre-operative radiographs immediate post-operative radiographs Judet views useful for assessment of columns CT scan indications useful for determining extent of osteolysis radiographs frequently underestimate extent of osteolysis angiogram to determine relationship to neurovascular structures with Paprosky IIIB defects assessment of component position Studies Serum labs infectious laboratories ESR CRP CBC metal levels cobalt and chromium levels trunnionosis THA pseudotumor Aspiration recommended if infectious laboratories are suggestive of infection Treatment Nonoperative indications differing etiology of pain (i.e. back pain, greater trochanteric bursitis, etc.) no identifiable etiology of pain Operative Femoral revision primary total hip arthroplasty components indications minimal metaphyseal bone loss, Paprosky I uncemented extensively porous-coated long-stem prosthesis (or porous-coated/grit blasted combination) or modular tapered stems indications most Paprosky II and IIIa defects; Paprosky IIIb (modular fluted tapered stem) outcomes 95% survival rate at 10-years femoral impaction bone grafting indications large ectactic canal and thin cortices Paprosky IIIb and IV defects outcomes most common complication is stem subsidence allograft prosthetic composite (APC) indications Paprosky IIIb and IV defects endoprosthetic replacement (EPR) indications massive bone loss with a non-supportive diaphysis Paprosky IIIB and IV defects cemented stems indications irradiated bone elderly with severe osteopenia Dorr C femur outcomes high failure rate Acetabular revision porous-coated hemisphere cup or jumbo secured with screws indications at least 50% of bone stock present to support cup disadvantage jumbo cup may disrupt posterior column with additional bone reamed dislocation porous-coated hemispherical cup with acetabular augments indications bone loss (Paprosky defects Type IIB-C and IIIA-B) outcomes 2 year survivorship 94%-100% 5 year survivorship 92%-100% 10 year survivorship 92% reconstruction cage with structural bone allograft indications rim is incompetent (<2/3 of rim remaining), <50% of bone stock present outcomes allograft failure is the most common complication high failure rate (40-60%) without reconstruction cage due to component migration after graft resorption custom triflange cup indications pelvic discontinuity cemented acetabular components can cement a liner by itself or into a well fixed cup liner options e.g. face changing, oblique, lipped, offset, contrained, dual mobility, etc. Combined revision femoral head and polyethylene exchange indications eccentric wear of the polyethylene with stable acetabular and femoral components acute infection trunnionosis outcomes hip instability is the most common complication of isolated liner exchange conversion from a hip arthrodesis indications low back and knee pain as a result of arthrodesis outcomes implant survival greater than 95% at 10 years competence of abductor and gluteal musculature is predictive of ambulatory success improved ipsilateral knee and back pain Revision without changed modular or nonmodular components ORIF periprosthetic fracture indications fracture with stable components psoas release indications painful psoas with clinical signs of impingement and improvement with lidocaine injection can be completed arthroscopically heterotopic bone excisions indications mature heterotopic bone formation causing pain and restricted range of motion Surgical Techniques Femoral revision primary total hip arthroplasty components technique must be sure there is no unexpected bone loss uncemented extensively porous-coated long-stem prosthesis or modular tapered stems technique removal of stem may require extended trochanteric osteotomy (ETO) ETO decreases load to failure (fracture) femoral stem must bypass most distal defect by 2 cortical diameters prevents bending moment through cortical hole cavitary lesions are grafted with particulate graft allograft cortical struts or plates may be used to reinforce cortical defects femoral impaction bone grafting technique morselized fresh-frozen allograft packed into canal smooth tapered stem cemented into allograft allograft prosthetic composite (APC) technique measure host canal size, allograft canal size should be slightly larger than distal host canal mark rotation and make femoral osteotomy (transverse or step) cut on host bone allograft is prepared (usual neck cut and canal reamining) for cementing of fully porous-coated stem host femur is prepared with straight reamers with goal of 4-6cm of good scratch fit distal to osteotomy component is cemented into allograft and press fit into host bone endoprosthetic reconstruction (EPR) technique a sample of bone from distal femoral osteotomy should be sent for frozen section to confirm no tumor cells are present prior to instrumenting option for distal fixation include a cemented stemmed endoprosthesis, compressive osseointegration, or a press-fit fully porous-coated cylindrical stem cemented stems technique bone grafting of any femoral defects prior to cementing ensure canal preparation has removed old cement, neocortex (greater and less troch), and sclerotic bone for cement interdigitation may require extended trochanteric osteotomy with difficult cement mantle/spacer removal Acetabular revision porous-coated hemisphere cup or jumbo secured with screws technique cavitary lesions are filled with particulate graft cup placement should be inferior and medial lowers joint reactive forces metallic wedge augmentation may be used if cup in good position and rigid internal fixation is achieved jumbo cups may be used when larger reamer is needed to make cortical contact structural allografts may be used to provide stability while bone grows into cementless cup porous-coated hemispherical cup with acetabular augments technique gentle reaming to smooth the acetabulum and minimizing the removal of good supportive bone assess cup size with trials and location for augments fix the augment with screws place small amount of cement on the augment and place real cup to unite the augment to the cup place screws in the cup, goal is to have a screw go through the cup and augment reconstruction cage and structural bone allograft technique polyethylene cup is cemented into reconstruction cage bone graft placed behind cage custom triflange technique sterilize custom triflanged acetabular component (CTAC) model for intraopeative reference removal of prior implant and assess needed excess bone removal place iliac flange first followed by pubic and ischial flange secure with screw fixation consider placement of posterior column plate cemented cup technique cement polyethylene into stable cup Combined revision Femoral head and polyethylene exchange technique exchange both head and liner osteolytic defects may be bone grafted through screw holes to fill bony defects Conversion from hip arthrodesis technique osteotomy of remaining greater trochanter femoral neck ostoetomy and acetabular reaming can be done under radiographic guidance given limitations in bony landmarks consideration for revision cup and femoral stem as well as dual mobility or constrained liner given high dislocation rate if abductor deficiency can perform glut max transfer along with the tensor fascia lata, the anterior aspect of the gluteus maximus is freed and transferred to the greater trochanter so that the fibers are similarly oriented to the native abductor musculature Revision without changed modular or nonmodular components ORIF periprosthetic fracture technique assess stability of components, if stable treat fracture and if unable revise see topic page psoas release technique see topic page heterotopic bone (HO) excision technique await maturation of bone excision of bone should be followed by HO prophylaxis of either NSAIDs, radiation, or both. Prognosis Lower mid-term and long term survival compared to primary THA with higher rates of complications dislocation (even in simple procedures) infection nerve palsy fractures abductor deficiency DVT limb length discrepancy