Introduction Osteolysis represents a histiocytic response to wear debris. Steps in the process include (see below) particulate debris formation macrophage activated osteolysis prosthesis micromotion particulate debris dissemination Evaluation radiostereometric analysis is the most accurate and precise technique to evaluate polyethylene wear uses radiopaque tantalum beads planted in the bone to follow the position of the components relative to the beads on radiographs. Step 1: Particulate Debris Formation Types of wear adhesive wear most important in osteolytic process microscopically PE sticks to prosthesis and debris gets pulled off abrasive wear cheese grater effect of prosthesis scraping off particles third body wear particles in joint space cause abrasion and wear volumetric wear main determinant of number of particles created directly related to square of the radius of the head volumetric wear more or less creates a cylinder V=3.14rsquaredw V is volumetric wear, r is the radius of head, w is linear head wear head size is most important factor in predicting particles generated linear wear is measured by the distance the prosthesis has penetrated into the liner Wear leads to particulate debris formation wear rates by material polyethylene non-cross linked UHMWPE wear rate is 0.1-0.2 mm/yr linear wear rates greater than 0.1 mm/yr has been associated with osteolysis and subsequent component loosening highly-cross linked UHMWPE generates smaller wear particles and is more resistant to wear (but has reduced mechanical properties compared to conventional non-highly cross-linked) factors increasing wear in THA thickness < 6mm malalignment of components patients < 50 yo men higher activity level femoral head size between 22 and 46mm in diameter does not influence wear rates of UHMWPE ceramics ceramic bearings have the lowest wear rates of any bearing combination (0.5 to 2.5 µ per component per year) ceramic-on-polyethylene bearings have varied, ranging from 0 to 150 µ. has a unique complication of stripe wear occurring from lift-off separation of the head gait recurrent dislocations or incidental contact of femoral head with metallic shell can cause "lead pencil-like" markings that lead to increased femoral head roughness and polyethylene wear rates. metals metal-on-metal produces smaller wear particles as well as lower wear rates than those for metal-on-polyethylene bearings (ranging from 2.5 to 5.0 µ per year) titanium used for bearing surfaces has a high failure rate because of a poor resistance to wear and notch sensitivity. metal-on-metal wear stimulates lymphocytes metal-on-metal serum ion levels greater with cup abduction angle >55 degrees and smaller component size Particulate Type UHMWPE most common PMMA Co-Cr Ti third-body Particulate size is < 1 micron Step 2: Macrophage Activated Osteoclastogenesis and Osteolysis Macrophage activation results in macrophage activation and further macrophage recruitment macrophage releases osteolytic factors (cytokines) including TNF- alpha osteoclast activating factor oxide radicals hydrogen peroxide acid phosphatase interleukins (Il-1, IL-6) prostaglandins Osteoclast activation and osteolysis increase of TNF- alpha increases RANK increase of VEGF with UHMWPE inhances RANK and RANKL activation RANKL mediated bone resorption an increase in production of RANK and RANKL gene transcripts leads to osteolysis Step 3: Prosthesis Micromotion Osteolysis surrounding the prosthesis leads to micromotion micromotion leads to increase particle wear and further prosthesis loosening N-telopeptide urine level is a marker for bone turnover and are elevated in osteolysis Step 4: Debris Dissemination Increase in hydrostatic pressure leads to dissemination of debris into effective joint space increased hydrostatic pressure is result of inflammatory response dissemination of debris into effective joint space further propagates osteolysis circumferentially coated prosthesis limits osteolysis in the distal femur
QUESTIONS 1 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ12.246) A 72-year-old female underwent an uncomplicated primary total hip replacement 18 years ago. Current radiographs reveal the abnormality shown in Figure A. Which of the following cell types (Figures B-F) is implicated in the process shown by the arrow? Tested Concept QID: 4606 FIGURES: A B C D E F Type & Select Correct Answer 1 Figure B 9% (322/3546) 2 Figure C 11% (380/3546) 3 Figure D 6% (214/3546) 4 Figure E 2% (86/3546) 5 Figure F 71% (2512/3546) L 3 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review tested concept (OBQ12.177) Which of the following variables is associated with elevated serum metal ion levels following metal-on-metal hip resurfacing arthroplasty? Tested Concept QID: 4537 Type & Select Correct Answer 1 Smaller implant diameter 41% (1507/3673) 2 Smaller acetabular cup abduction angle 28% (1031/3673) 3 Higher postoperative functional scores 22% (825/3673) 4 Severe preoperative osteoarthritis 2% (88/3673) 5 Anteversion of acetabular cup between 10 and 20 degrees 5% (196/3673) L 4 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review tested concept (OBQ12.196) A patient undergoes a primary total hip arthroplasty with a highly cross-linked ultra-high molecular weight (UHMW) polyethylene acetabular liner. In comparison to a 28mm femoral head, a 32mm femoral head will provide which of the following? Tested Concept QID: 4556 Type & Select Correct Answer 1 Increased risk of dislocation 3% (139/4682) 2 Decreased range of motion 9% (444/4682) 3 Decreased risk of osteolysis 20% (934/4682) 4 Equivalent wear rate of the polyethylene acetabular liner 64% (3005/4682) 5 Increased risk of periprosthetic fracture 2% (117/4682) L 4 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept (OBQ12.117) Which of the following molecules is associated with macrophage induced osteolysis surrounding orthopaedic implants? Tested Concept QID: 4477 Type & Select Correct Answer 1 BMP-7 2% (82/4210) 2 IL-10 10% (420/4210) 3 SOX-9 2% (100/4210) 4 Osteoprotegrin 6% (248/4210) 5 IL-1 79% (3328/4210) L 2 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review tested concept (OBQ12.68) Which of the following is indicative of type 1 collagen breakdown and can be utilized as a marker of bone turnover? Tested Concept QID: 4428 Type & Select Correct Answer 1 Increased urinary N-telopeptide 70% (3236/4616) 2 Increased urinary cAMP and phosphate 14% (637/4616) 3 Increased urinary phosphoethanolamine 6% (259/4616) 4 Increased urinary Bence Jones proteins 3% (134/4616) 5 Increased serum bone sialoprotein 7% (316/4616) L 3 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review tested concept (OBQ11.191) A 56-year-old man reports progressively worsening left knee pain after undergoing total knee arthroplasty 6 years ago. He was initially very happy with his progress, but 18 months after surgery he began to have knee pain. Radiographs are shown in Figures A and B. Laboratory values reveal a C-reactive protein of 0.1 mg/dL (normal 0.0-0.6 mg/dL) and an erythrocyte sedimentation rate of 3 mm/h (normal 0-15 mm/h). An aspiration of the knee reveals 157 leukocytes/ml with 18% polymorphonucleocytes. What is the most appropriate next step in management? Tested Concept QID: 3614 FIGURES: A B Type & Select Correct Answer 1 One-stage revision 91% (2966/3273) 2 Irrigation and debridement with polyethylene spacer exchange 2% (74/3273) 3 Antibiotic impregnated cement spacer placement 1% (20/3273) 4 Two-stage revision 6% (182/3273) 5 Broad-spectrum, empiric oral antibiotics 1% (18/3273) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review tested concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ10.259) A design surgeon has created a new polyethlyene acetabular liner for total hip arthroplasty. Early clinical outcomes are comparable to conventional total hip arthroplasty. At 4 year follow-up, radioisometric analysis reveals 0.05 mm of annual wear in the surgeon's trial patients. Which of the following statements can be made from this data? Tested Concept QID: 3311 Type & Select Correct Answer 1 Osteolysis and subsequent component loosening will be minimal if the wear rate continues 69% (2072/3017) 2 Osteolysis and subsequent component loosening will be greater than conventional hip arthroplasty if the wear rate continues 21% (648/3017) 3 Component positioning should have no effect on wear rates of these bearings 8% (240/3017) 4 All total hip arthroplasties should use this new polyethylene 1% (29/3017) 5 Patient satisfaction will be greater at 10 year follow up 0% (13/3017) L 3 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review tested concept (OBQ10.116) A new biomaterial has been designed for hard on soft bearings in total hip arthroplasty. The implant company claims this new material has a lower wear rate and greater toughness than highly cross linked polyethylene. Which of the following studies would most accurately evaluate wear between the two materials? Tested Concept QID: 3210 Type & Select Correct Answer 1 Retrospective review of each material with immediate post-operative radiographs compared to annual follow-up radiographs 1% (15/2173) 2 Prospective trial comparing each material with radiostereometric analysis 83% (1799/2173) 3 Prospective trial comparing each material with annual CT scans 3% (61/2173) 4 Prospective trial comparing each material with computer-assisted edge-detection radiographs 13% (284/2173) 5 Retrospective trial comparing each material with computer-assisted edge-detection radiographs 0% (9/2173) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review tested concept (OBQ10.39) A 45-year-old male, with a history of avascular necrosis, undergoes a total hip arthroplasty using a metal-on-metal bearing. Which of the following statements regarding the use of metal-on-metal bearings is true? Tested Concept QID: 3127 Type & Select Correct Answer 1 Produce lower serum metal ion concentrations than metal-on-cross linked polyethylene bearings 1% (17/2922) 2 Have a decreased volumetric wear rate compared to metal-on-ceramic bearings 11% (323/2922) 3 Have smaller wear particles compared to metal-on-cross linked polyethylene bearings 76% (2227/2922) 4 Have a higher incidence of early soft-tissue sarcoma compared to all other bearing surfaces. 7% (203/2922) 5 The wear rate significantly increases after the first year of use. 5% (141/2922) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review tested concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ09.180) Osteoprotegrin (OPG) binds to what structure to inhibit particle-induced osteolysis? Tested Concept QID: 2993 Type & Select Correct Answer 1 RANK 17% (466/2701) 2 RANK-ligand 75% (2039/2701) 3 OPG-receptor 6% (171/2701) 4 CD7 0% (6/2701) 5 CD10 0% (11/2701) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review tested concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (OBQ08.245) Which type of inflammatory cell is thought to be involved in the activation of the biological response to metal-on-metal particulate debris? Tested Concept QID: 631 Type & Select Correct Answer 1 Neutrophil 1% (62/4326) 2 Giant cell 1% (48/4326) 3 Macrophage 27% (1165/4326) 4 Eosinophil 1% (60/4326) 5 Lymphocyte 69% (2980/4326) L 3 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review tested concept (OBQ08.116) All of the following are risk factors for wear-related failure in total knee arthroplasty when using a polyethylene liner that underwent sterilization via gamma irradiation in air EXCEPT? Tested Concept QID: 502 Type & Select Correct Answer 1 Increasing shelf age of polyethylene liner 7% (84/1242) 2 Younger age of patient 1% (18/1242) 3 Male gender 10% (123/1242) 4 Posterior cruciate retaining knee design 74% (925/1242) 5 Use of a rough tibial baseplate 7% (84/1242) L 3 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK This is an AAOS Self Assessment Exam (SAE) question. Orthobullets was not involved in the editorial process and does not have the ability to alter the question. If you prefer to hide SAE questions, simply turn them off in your Learning Goals. (SAE07HK.97) Which of the following is the primary mechanism of polyethylene wear in the hip? Tested Concept QID: 6057 Type & Select Correct Answer 1 Fatigue cracking and delamination 11% (44/408) 2 Oscillatory fretting 5% (22/408) 3 Crevice corrosion 4% (16/408) 4 Oxidative degradation 8% (31/408) 5 Adhesion and abrasion 72% (294/408) L 3 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review tested concept (OBQ07.236) Ultra-high-molecular-weight polyethylene (UHMWPE) particles have been associated with osteoclastogenesis, a key component of osteolysis in total joint replacement. Which of the following accurately describes the expression of vascular endothelial growth factor (VEGF) and receptor activator of nuclear factor kappa-B ligand (RANKL) during UHWMPE induced osteolysis? Tested Concept QID: 897 Type & Select Correct Answer 1 RANKL expression is increased and VEGF is unchanged or mildly decreased 14% (296/2077) 2 VEGF expression is increased and RANKL is decreased 4% (84/2077) 3 VEGF expression is increased and RANKL expression is unchanged 3% (65/2077) 4 Expression of both VEGF and RANKL is increased 77% (1593/2077) 5 Expression of both VEGF and RANKL is decreased 2% (32/2077) L 1 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept (OBQ07.11) Figure A is a photograph of a femoral head removed during revision of a ceramic on ceramic total hip arthroplasty. Which of the following is the most likely indication for this revision total hip arthroplasty? Tested Concept QID: 672 FIGURES: A Type & Select Correct Answer 1 Prosthetic infection 0% (8/1670) 2 Recurrent dislocations 82% (1362/1670) 3 Leg length discrepancy 1% (24/1670) 4 Ceramic bearing fracture 12% (194/1670) 5 Aseptic lymphocytic-vasculitis-associated lesion (ALVAL) 5% (78/1670) L 2 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review tested concept (OBQ07.145) Highly cross-linked ultra-high-molecular-weight polyethylene (UHMWPE) liners used in total hip arthroplasty have which of the following characteristics compared to conventional UHMWPE liners? Tested Concept QID: 806 Type & Select Correct Answer 1 Increased average wear particle size 3% (78/2484) 2 Increased resistance to abrasive wear 79% (1960/2484) 3 Increased number of wear particles generated 5% (125/2484) 4 Increased resistance to fatigue crack propogation 9% (229/2484) 5 Increased ductility 3% (82/2484) L 2 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review tested concept (OBQ07.205) Highly cross-linked ultra high molecular weight polyethylene has which of the following characteristics as compared to conventional polyethylene? Tested Concept QID: 866 Type & Select Correct Answer 1 Improved ductility 1% (27/3100) 2 Increased fracture toughness 1% (39/3100) 3 Increases the elongation to break 1% (17/3100) 4 Improved resistance to crack propagation 2% (47/3100) 5 Improved wear resistance 96% (2964/3100) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 5 Review tested concept (OBQ06.46) Figure A shows a ceramic head removed during a total hip revision. The component shows damage to the femoral head which was most likely caused by which of the following? Tested Concept QID: 157 FIGURES: A Type & Select Correct Answer 1 Third body debris 20% (288/1473) 2 Chronic infection 0% (5/1473) 3 Impingement of the femoral stem neck on the acetabular socket 18% (271/1473) 4 Lift-off separation of the femoral head during hip range of motion 55% (815/1473) 5 Insertion of the head on the femoral stem at time of initial surgery 6% (90/1473) L 3 Question Complexity C Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review tested concept (OBQ06.220) Which of the following interventions reduces osteolysis around distal portion of the femoral stem when performing a total hip arthroplasty? Tested Concept QID: 231 Type & Select Correct Answer 1 Use of an extended offset femoral neck component 1% (17/1137) 2 Use of a proximal circumferentially coated ingrowth stem 65% (743/1137) 3 Use of a collared stem 3% (33/1137) 4 Use of a long femoral stem 2% (19/1137) 5 Ensuring that the stem fills the diaphysis of the femur 28% (320/1137) L 3 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 2 Review tested concept (OBQ05.146) A 75-year-old man underwent total hip arthroplasty 10 years ago. He now reports mild groin pain which has been increasing lately. What is the most likely explanation for the finding in Figure A indicated with the arrows? Tested Concept QID: 1032 FIGURES: A Type & Select Correct Answer 1 Osteosarcoma 0% (5/2497) 2 Galvanic corrosion of the modular components 5% (127/2497) 3 Polyethlene wear particles tracking through the effective joint space 92% (2305/2497) 4 Joint sepsis 1% (24/2497) 5 Occult fracture 1% (26/2497) L 1 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review tested concept (OBQ05.63) When comparing conventional polyethylene liners to the newer highly cross-linked polyethylene liners, all of the following are true EXCEPT for one. Which of these statements about conventional poly liners is incorrect? Tested Concept QID: 949 Type & Select Correct Answer 1 Higher steady-state femoral head penetration rate 7% (112/1713) 2 More susceptible to adhesive wear 12% (197/1713) 3 Generate smaller wear particle size 58% (999/1713) 4 Increased fracture toughness 13% (224/1713) 5 Increased tensile strength 10% (177/1713) L 3 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review tested concept (OBQ04.92) Osteolysis occurs because there is a histiocytic response by macrophages to wear debris. What size particles are implicated in osteolysis? Tested Concept QID: 1197 Type & Select Correct Answer 1 less than 1 micron (submicron) 39% (1191/3026) 2 approximately 10 microns 22% (669/3026) 3 approximately 100 microns 34% (1017/3026) 4 approximately 1000 microns 3% (102/3026) 5 approximately 5000 microns 1% (30/3026) L 4 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review tested concept (OBQ04.196) A 69-year-old female 16 years status post total knee arthroplasty complains of knee pain. A radiograph is provided in Figure A. Which of the following is true regarding the pathogenesis of the bony abnormality seen in the distal femur? Tested Concept QID: 1301 FIGURES: A Type & Select Correct Answer 1 It is related to the toughness of the polyethylene liner 3% (68/2483) 2 It is more likely to occur with highly cross-linked polyethylene compared to conventional polyethylene 1% (35/2483) 3 It is caused by macrophage activation by polyethylene particles 94% (2330/2483) 4 It is most frequently caused by infection 1% (15/2483) 5 It occurs more frequently in patients taking immunosuppressive medications. 1% (27/2483) L 1 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review tested concept
All Videos (1) Podcasts (6) Adult Reconstruction Core Webinars - by AAHKS, Hip Society, Knee Society, and AAOS Core Webinar - RECON BASIC SCIENCE - by AAHKS Derek Moore Recon - Wear & Osteolysis Basic Science A 2/4/2017 4164 views (5) Question Session⎪Wear & Osteolysis Basic Science Orthobullets Team Recon - Wear & Osteolysis Basic Science Listen Now 31:1 min 5/13/2020 200 plays (1) Recon⎪Wear & Osteolysis Basic Science Orthobullets Team Recon - Wear & Osteolysis Basic Science Listen Now 7:3 min 5/13/2020 54 plays (1) Question Session⎜Wear & Osteolysis Basic Science, Catastrophic Wear & PE Sterilization Orthobullets Team Recon - Wear & Osteolysis Basic Science Listen Now 47:10 min 11/11/2019 38 plays (1) Question Session⎪Wear & Osteolysis Basic Science Orthobullets Team Recon - Wear & Osteolysis Basic Science Listen Now 31:1 min 11/5/2019 26 plays (1) Recon⎪Wear & Osteolysis Basic Science Orthobullets Team Recon - Wear & Osteolysis Basic Science Listen Now 7:3 min 11/5/2019 59 plays (2) Recon⎜Wear & Osteolysis, Catastrophic Wear & PE Sterilization (ft. Dr. Javad Parvizi) Team Orthobullets 4 Recon - Wear & Osteolysis Basic Science Listen Now 9:40 min 10/18/2019 63 plays (2)