Arthroplasty - RC Q's

Question 1

RC 2009 With regards to patellar resurfacing. All of the following except: <ol> <li>Metal backed patella do better than all poly</li> <li>Rotation of 3-5deg of femoral component is better than neutral</li> <li>Subluxation is more common than dislocation</li> <li>Lateralizing femoral component helps</li></ol>

Answer 1

A<div>Garcia RM (CORR 2008) Isolated all-poly patellar revision for metal-backed patella failure<br></br></div>

Question 2

RC 2017 - Increasing articular congruity of a polyethylene tibial component in a fixed bearing TKA will have what effect? <ol> <li>Decreased contact stress in the polyethylene</li> <li>Decreased patellofemoral maltracking</li> <li>Decreased forces at tibial tray interface with bone</li> <li>Increased posterior tibial roll-back (yes it said tibial)</li></ol>

Answer 2

A.<div><ul> <li>Increased conformity at the tibiofemoral articulation increases contact area and reduces contact stresses in total knee arthroplasty</li> <li>Increasing congruity = more constraint = increase in force @ tibial tray-bone interface</li></ul></div>

Question 3

RC 2009 - What is true about mobile bearing TKR’s? <ol> <li>Better flexion</li> <li>No benefit shown in literature</li> <li>Better wear properties</li> <li>Longevity</li></ol>

Answer 3

B.<div><ul> <li>Allows motion at the interface between the undersurface of the tibial polyethylene and the top surface of the tibial base plate.</li> <li>Advocates believe it allows for increased ROM, lower polyethylene stresses, and a more idealized kinematic knee function.</li> <li>Increasing conformity of tibial liner implants reduces polyethylene stress but increases stress at the tibial fixation interfaces.</li> <li>A theoretical advantage for mobile-bearing TKA is that the articular surface of the implant can be congruent over the entire ROM without increasing constraint.</li> <ul> <li>This leads to lower contact stresses as a result of increasing contact area.</li> <li>Some authors believe lower contact stresses will translate into a lower incidence of osteolysis.</li> </ul> <li>Data do not exist to show whether these apparent advantages with regard to contact stresses actually translate into decreased wear and osteolysis in vivo.</li></ul></div>

Question 4

RC Exam - When doing a PCL-sacrificing total knee arthroplasty which is true? <ol> <li>can raise joint line 12mm </li> <li>resection of PCL increases flexion arc 3-5mm</li> <li>better ROM postop with PCL retaining (or vice versa)</li> <li>better long term outcome with PCL-sacrificing (or maybe retaining)</li></ol>

Answer 4

B - the rest are false<div><ul> <li>PCL retaining knees have better survival</li> <li>Slightly better ROM with sacrificing –> but not clinically significant</li> <li>All patients getting arthroplasty have slight elevation of joint line, but no difference between implant types; elevating joint>8mm leads to poor outcomes</li></ul></div>

Question 5

RC 2008 - Regarding the mechanical axis in the tibia, all are true except? <ol> <li>Colinear and parallel in coronal plane</li> <li>Colinear and parallel in sagittal plane</li> <li>Mechanical and anatomical tibia axes are colinear</li> <li>LE axis passes 8 mm medial to tibial spines</li></ol>

Answer 5

“<div>tibia coronal plane is equal for anatomic and mechanical axes</div><div><br></br></div><div>C - true in coronal plane</div>D - true<div><br></br></div><div><img></img><br></br></div>”

Question 6

<div>RC 2012 - 6 anatomical releases for balancing a varus knee</div>

Answer 6

<ul> <li>Removal of osteophytes</li> <li>Medial capsule</li> <li>Posterior oblique ligament</li> <li>Superficial MCL</li> <li>Semimembranosus fibres</li> <li>PCL</li> <li>Pes anserine</li> <li>Medial Gastrocnemius</li> <li>Deep MCL</li></ul>

Question 7

RC 2016 - List 4 soft tissue releases for a valgus knee in TKA

Answer 7

<ul> <li>IT Band</li> <li>Posterolateral Capsule</li> <li>LCL</li> <li>Popliteus Tendon </li> <li>Lateral Head of Gastrocnemius</li> <li>PCL</li></ul>

Question 8

<div>RC 2014, 2011 - List 3 technique to determine rotation of the femoral component in TKA.</div>

Answer 8

“<ul> <li>Trans-epicondylar axis</li> <li>Perpendicular to Whiteside’s Line</li> <li>3o ER from posterior condylar axis</li> <li>Parallel to cut surface of tibia (gap balancing)</li> <li>Computer Navigation</li><li>IF DOING DFR: LINEA ASPERA, PF TRACKING</li> <ul> <li><img></img></li> </ul></ul>”

Question 9

RC 2012 - Why do you ER the femoral component in a TKA <ol> <li>Brendan likes boys</li> <li>Make a rectangular flexion gap</li> <li>Because Femur is 6 degrees and tibia 3 degrees</li></ol>

Answer 9

“B.<div><br></br></div><div><img></img><br></br></div>”

Question 10

RC 2011 - When performing TKA for varus knee, medial side is tight. Release semimembranosus. What does this effect? <ol> <li>It affects flexion gap more extension gap</li> <li>It affects both flexion and extension equally</li> <li>It affects extension gap more than flexion gap</li> <li>It affects the flexion gap only if the PCL is gap</li></ol>

Answer 10

C.<div><br></br></div><div><ul> <li>JAAOS - Soft Tissue Balancing in the Varus Knee</li> <ul> <li>sMCL will improve flexion and extension gaps</li> <li>POL affects mostly extension space</li> <li>Semimembranosus tendon affects extension space more than flexion</li> <li>Pes Tendons –> affect extension gap (surprising) - Campbells says that pes tendons affect flexion gap more</li> </ul></ul></div>

Question 11

RC 2014 - List 3 soft tissue releases to improve your flexion gap in performing a TKA

Answer 11

<ol> <li>Posterior Capsule</li> <li>Gastrocnemius</li> <li>Medial and lateral posterior corners</li> </ol>

<ul> <li>popliteus</li> </ul>

<ol> <li>PCL</li> <li>Anterior superficial MCL</li></ol>

Question 12

RC 2010 - Surgeon wants to use extramedullary referencing for tibia cuts in a total knee arthroplasty. If he ignores the rotational mismatch between the ankle and the tibial tubercle, what will the result? <ol> <li>No coronal malalignment </li> <li>Varus malalignment on coronal</li> <li>Valgus malalignment on coronal</li> <li>Increase posterior slope cut into tibia</li> </ol> <div><br></br></div>

Answer 12

“B.<div><ul> <li>JBJS. 2005. The effect of ankle rotation on cutting of the tibia in total knee arthroplasty.</li> </ul> <ul> <li>When an extramedullary alignment guide is used to prepare the tibia in total knee arthroplasty, varus alignment of the tibial component can occur because of a rotational mismatch between the proximal part of the tibia and the ankle joint</li> <li>The AP axis of the ankle is usually ER in relation to the AP axis of the proximal tibia</li> <li>This results in lateral displacement of the extra-medullar tibial guide if it is lined up with the AP axis of the ankle distally</li> <li>This will result in more medial bone resection proximally on the tibia, creating varus malalignment of your TKA</li> <li>To avoid tibial malalignment, it is important to first place the extramedullary alignment guide at right angles to the proximal tibial anteroposterior axis and then the distal end of the extramedullary guide should be placed at the center of the ankle joint</li> </ul> <div><img></img></div></div>”

Question 13

RC 2012 - 6 types of failure of a TKA requiring a revision

Answer 13

<ul> <li>Infection</li> <li>Patello-femoral instability</li> <li>Aseptic Loosening/Osteolysis</li> <li>Extensor Mechanism Disruption</li> <li>Peri-prosthetic Fracture</li> <li>Instability (varus/valgus)</li> <li>Arthrofribrosis/Stiffness</li> <li>Metal Allergy</li></ul>

Question 14

RC 2015 - What is the only advantage <b><u>to not </u></b>resurfacing the patella in TKA? <div> a. less complications</div> <div> b. decreased dislocation</div> <div> c. improved patellar tracking</div> <div> d. less anterior knee pain</div>

Answer 14

A.<div><ul> <li>JAAOS 2000 - Patellar Resurfacing in TKA</li> <ul> <li>“…complications included patellar fracture, patellar subluxation or dislocation, exten- sor mechanism disruption, and component wear, loosening, or dissociation. Many of these complications occurred only with, or <b>were much more common with, resurfaced patellae</b>.” </li> </ul> <li>(CORR 2005) Failure to resurface the patella during total knee arthroplasty may result in <b><u>more knee pain and secondary surgery</u></b></li> <ul> <li>Meta-analysis</li> <li>More anterior knee pain without patellar resurfacing</li> </ul></ul></div><div><br></br></div>

Question 15

RC 2012, 2010, 2009 - Bilateral TKA, what risk goes up?<ol> <li>DVT</li> <li>Bleeding</li> <li>CV events</li> <li>Periprosthetic infections</li></ol>

Answer 15

C.<div><br></br></div><div><div>Restrepo C (JBJS 2007) Safety of Simultaneous Bilateral TKA: A Meta-analysis</div> <ul> <li>150 articles with 27,807 patients included</li> <li>Simultaneous TKA:</li> <ul> <li>Higher:</li> <ul> <li>Higher PE (OR 1.8)</li> <li>Cardiac complications (OR 2.49)</li> <li>Mortality (OR 2.2)</li> </ul> <li>Lower:</li> <ul> <li>DVT (not significant though)</li> </ul> </ul></ul></div>

Question 16

RC 2008 - HO and TKA, risk factors - all of the following except <ol> <li>Femur Notching</li> <li>RA</li> <li>Manipulation post-op</li> <li>Female with hypertrophic osteoarthropathy</li></ol>

Answer 16

B.<div><br></br><div><div>Patients at high risk for developing HO after TKA include those with limited post-op knee flexion, increased lumbar BMD, hypertrophic arthrosis, excessive periosteal trauma, notching of the anterior femur, those who require forced manipulation after TKA</div></div><div><br></br></div></div>

Question 17

RC 2017 - 75 female, 18 months post TKA, comes in with ongoing pain. States it “never felt good”. ROM is full. What is most likely diagnosis? <div>A. Stress fracture</div> <div>B. Infection</div> <div>C. Aseptic loosening</div> <div>D. Ligament instability</div>

Answer 17

D.

Question 18

RC 2011 - Patient has TKA, wakes up with peroneal nerve injury in PACU. What was their deformity <div>A. Rigid Varus</div> <div>B. Rigid Valgus with flexion contracture</div> <div>C. Correctable varus</div> <div>D. Correctable valgus</div> <div></div>

Answer 18

B.<div><br></br></div><div><div>Peroneal nerve palsy = correction ofvalgus and flexion contracture deformityhas highest risk of peroneal nerve palsy</div></div><div><br></br></div>

Question 19

RC 2016 - A patient is 8 weeks postop from a TKA and has significant stiffness. Given an AP, skyline and lateral x-ray which are totally normal. What do you do? <ol> <li>Manipulate under anesthesia</li> <li>Revise to stemmed components</li> <li>Arthroscopic lysis of adhesions</li> <li>Open lysis of adhesions</li></ol>

Answer 19

A.<div>Patients with early-onset stiffness (<90o of flexion or significant flexion contracture < 3 months after surgery) and had adequate preoperative and intra-operative Rom but are not progressing with physical therapy should be considered for manipulation <div></div></div><div><br></br></div>

Question 20

RC 2011 - Most important predictor of post-op ROM of TKA <ol> <li>Use of PS knee</li> <li>pre-op motion</li> <li>high flex knee</li> <li>participation in PT</li></ol>

Answer 20

B. dont be dumb

Question 21

RC 2009 - Hemophiliac has a TKA. All of the following are true, except: <ol> <li>Need to keep factor levels at 60% x 2wks post</li> <li>Lots of problems w/ joint instability</li> <li>If you take away infection, revision rates = everyone else</li> <li>Post op hemarthrosis is most common at 4-7d post op</li></ol>

Answer 21

B<div><br></br></div><div>-pts are stiff, not lax</div><div><b>-higher risk of infection! (MCQ 2008)</b></div><div>-replace to 100% pre-op then 60% post-op</div><div><ul> <li>Two hours pre-op replace factor level to 100% with IV infusion</li> <ul> <li>Check for factor level with factor assay</li> </ul> <li>Intra-operative- keep factor at >60%</li> <li>Post-operative in hospital- keep factor at >60% until discharge</li> <ul> <li>Recheck levels every 1-2 days</li> </ul> <li>Post-operative at home- keep factor at 30-60% normal level for 2 weeks post-op</li></ul></div>

Question 22

<div>RC 2017, 2015, 2014 - For post-traumatic or post-operative arthrofibrosis of the knee, which is true?</div>

<ol> <li>Hoffa sign can help determine suprapatellar scarring</li> <li>Anterior arthrofibrosis prevents extension</li> <li>Manipulation under anesthesia should be performed within 12 weeks</li> <li>Flexion contracture of 5-10 degrees is usually well tolerated</li></ol>

Answer 22

“C.<div><br></br></div><div><ul> <li>The Hoffa test is for prepatellar fat pad. Firm pressure is applied with the thumb inferior to the patella outside the margin of the patellar tendon with the knee in (a) 30–60° of flexion. (b) The knee is fully extended, and increased pain in the infrapatellar fat pad indicates a positive test. The test is repeated on both the medial and lateral side</li> <li>One stem version refers to ““Anterior interval fibrosis””.</li> <ul> <li>Fibrosis of the posterior border of the IFP to the anterior surface of the tibia or transverse meniscal ligament, is termed ‘anterior interval scarring’, which effectively adheres the IFP to the anterior tibia.[7,8,56] If clinical presentation includes distal displacement of the patella (patellar infera), significant flexion contracture and decreased patellar mobility, the diagnosis of ‘infrapatellar contracture syndrome’ has been used</li> </ul> </ul> <ul> <li>JAAOS - Stiffness after Total Knee Arthroplasty:</li> <ul> <li>Patients with late-onset knee stiffness (>3 months after TKA and after adequate ROM had been achieved initially) are less likely to benefit from physical therapy</li> <li>"”Controversy continues regarding both the usefulness and timing of manipulation””</li> </ul> <li>Issa K (JBJS 2014) The Effect of timing of manipulation under anesthesia to improve range of motion and functional outcomes following total knee arthroplasty</li> <ul> <li>144 MUA - comparison of <6 weeks, 6-12 weeks, 13-26 weeks, >26 weeks</li> <li>Early manipulation gained more motion (36 vs 17o) and had higher final ROM</li> <li>No difference between <6 weeks and < 12 weeks</li> </ul></ul></div>”

Question 23

RC 2015, 2014, 2010 - 45yo male presents 8mos post TKA with ROM 0-70 (0-120 pre-op). What are 3 possible causes of his flexion deficiency

Answer 23

<ul> <li>Technical Errors:</li> </ul>

<ol> <li>Gap imbalance (ie too tight in flex)</li> <li>Component Malalignment, malrotation</li> <li>Patellofemoral overstuffing</li> <li>Joint line elevation/patella baja</li> <li>Posterior cement extra-vasation</li> </ol>

<li>Patient Factors:</li>

<ol> <li>Poor Pre-op ROM</li> <li>Poor patient motivation/rehabilitation</li> <li>Poor pain control</li> <li>Heterotopic ossification</li> <li>Aggressive anti-coagulation with hematoma</li> <li>Infection</li> </ol>

<li>Factors that do NOT affect ROM:</li>

<ol> <li>Obesity, previous OR, Keloid scar, age, sex, mutiple joint involvement, bilateral TKA</li> </ol>

Question 24

<div>RC 2015 - What is not a block to flexion following knee surgery:</div>

<ol> <li>Cyclops lesion</li> <li>Quads adhesions</li> <li>Adhesions in medial/lateral gutters</li> <li>Patella baja</li></ol>

Answer 24

A.<div><ul> <li>Cyclops lesions - anterior arthrofibrosis –> extension loss</li> <li>Quads adhesion –> tightening of extensor mechanism</li> <li>Patella baja –> shown to decrease flexion in TKA due to joint line elevation</li> <li>Arthrofibrosis –> causes decreased ROM in both directions</li></ul></div>

Question 25

RC 2014 - List three ways to prevent PF maltracking in TKA

Answer 25

<ol> <li>External rotation of tibial and femoral components</li> <li>Lateralization of tibial and femoral components</li> <li>Medialization of patellar component</li></ol>

Question 26

RC 2017 - In total knee arthroplasty, which will lead to patellar maltracking <div>A. Lateralization of femoral component</div> <div>B. Lateralization of tibial component</div> <div>C. Internal rotation of tibial component</div> <div>D. Medialization of patellar component</div>

Answer 26

C.<div><div>internal rotation in the transverse plane increases the Q angle of the knee joint and predisposes to lateral patellar maltracking and patellar instability</div></div>

Question 27

RC 2016 - What is the best way to assess implant malrotation following TKA? <ol> <li>Xray</li> <li>Physical exam</li> <li>Metal subtraction CT </li> <li>MRI</li></ol>

Answer 27

C.<div><ul> <li>Prior radiographs can aid in the evaluation of component position as well as assessment of component migration over time</li> <li>CT can provide detailed information regarding rotational malalignment of the femoral or tibial component</li></ul></div>

Question 28

RC 2017 - What are 5 complications associated with valgus producing HTO, excluding bleeding and infection:

Answer 28

<ul> <li>Recurrence of deformity</li> <li>Loss of posterior slope</li> <li>Patella baja</li> <li>Compartment syndrome</li> <li>Mal-union and non-union</li> <li>Peroneal nerve palsy</li></ul>

Question 29

RC 2012 - 4 contraindications to HTO

Answer 29

<ul> <li>Patient Factors</li> <ul> <li>Inflammatory arthritis</li> <li>BMI > 35</li> <li>Flexion contracture > 15deg</li> <li>Knee Flexion < 90</li> </ul> <li>Deformity</li> <ul> <li>>20o varus/valgus deformity</li> <li>Patellar arthritis</li> <li>Ligamentous instability/thrusting gait</li> <ul> <li>Can consider combined ACL reconstruction (controversial)</li> </ul> </ul></ul>

Question 30

RC 2016 - List 4 advantages of doing a medial opening wedge HTO over a lateral closing wedge.

Answer 30

<ul> <li>JAAOS 2005 - HTO/JAAOS 2011</li> <ul> <li>Easy to control correction (can dial it in)</li> <li>Less extensive surgical dissection/no disruption to proximal tib/fib joint</li> <li>Less proximity to peroneal nerve</li> <li>Can be combined with PF procedures</li> <li>No loss of lateral bone stock</li> </ul></ul>

Question 31

<div>RC 2015 -In performing an opening wedge HTO, all of the following are true except:</div>

<ol> <li>In an ACL deficient knee, placing the bone wedge posteromedially will decrease the tibial slope and decrease anterior translation </li> <li>In a PCL deficient knee, placing the bone wedge anteromedially will increase the tibial slope and increase posterior translation</li> <li>Placing the bone wedge direct medial will not affect the slope</li> <li>Smaller anterior gap with a larger posterior gap will preserve the native tibial slope</li></ol>

Answer 31

“<div>ANSWER: B</div> <ul> <li>2015</li> <li>Increased tibial slope will DECREASE posterior translation</li> <li>JAAOS 2011 - Role of the HTO in the varus knee</li> <ul> <li>ACL deficiency –> decrease tibial slope</li> <li>PCL deficiency –> increase tibial slope</li> </ul> </ul> <div><img></img></div> <ul> <li>Noyes (AJSM 2005) Opening wedge tibial osteotomy: the 3-triangle method to correct axial alignment and tibial slope</li> </ul> <div><img></img></div> <div>Need a 2:1 opening of posterior to anterior to preserve native slope when doing a medial opening wedge (Dr. French via Noyes)</div>”

Question 32

RC 2013 - A patient is being chemoprophylaxed against DVT/PE after a TKA. You are worried about HIT. What is true? <ol> <li>Because you used low molecular weight heparin, the patient is not at risk for thrombocytopenia. </li> <li>You need to start the HIT work up if platelets drop below 100,000.</li> <li>It can present 4 to 5 days after starting heparin</li></ol>

Answer 32

“C.<div><ol><li>Ahmen I (Postgrad Med J 2007) Heparin Induced thrombocytopenia: diagnosis and management update</li> </ol> <div><img></img></div> <ul> <li>0-3 points - HIT unlikely</li> <li>4-5 - intermediate possibility</li> <li>6-8 highly likely</li></ul></div>”

Question 33

RC 2015 - What has the lowest level of evidence for prevention of DVT in TJA? <ol> <li>LMWH</li> <li>Mechanical compression devices</li> <li>Rivoroxaban</li> <li>ASA</li></ol>

Answer 33

B.<div><br></br></div><div><ul> <li>CHEST Guidelines 2012</li> <ul> <li>“In patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA), we recommend use of one of the following for a minimum of 10 to 14 days rather than no antithrombotic prophylaxis: low-molecular-weight heparin (LMWH), fondaparinux, apixaban, dabigatran, rivaroxaban, low-dose unfractionated heparin (LDUH), adjusted-dose vitamin K antagonist (VKA), aspirin (all Grade 1B), or an intermittent pneumatic compression device (IPCD) (Grade 1C).</li> </ul></ul></div>

Question 34

RC 2017 - Risk factor for MI during arthroplasty <div>A. risk of MI is 10% in first 30 days</div> <div>B. MI usually happen 10 days after surgery</div> <div>C. Intra-operative cardiac monitoring can help prevent</div> <div>D. Risk factors include age >80, hypertension, previous heart disease</div>

Answer 34

D.<div><br></br></div><div><div>JAO 2016 Bemenderfer Morbidity and Mortality in Elective Total Knee Arthroplasty Following Surgical Care Improvement Project Guidelines.</div> <ul> <li>Several patient factors were associated with increased risk of developing cardiac complications</li> <ul> <li>Caucasian ethnicity</li> <li>Obesity </li> <li>Chronic obstructive pulmonary disease</li> <li>Hypertension</li> <li>End stage renal disease (ESRD)</li> <li>Age greater than 65 years</li> <li>Coronary artery disease</li> <li>Congestive heart failure (CHF)</li> </ul></ul></div>

Question 35

RC 2013 - What increases the incidence of cobalt chromium ions with MoM hips? <ol> <li>Cup in 55o abduction</li> <li>Increase in head size</li></ol>

Answer 35

A.<div><br></br></div><div>RFs for soft tissue reaction</div><div>-Pt: bilateral hips, obese, female</div><div>-Surgical: abducation>50 deg</div><div>-lab: metal ions>7ppb</div>

Question 36

RC 2014, 2011 - Picture of a BHR with a femoral neck fracture. Name 4 risk factors for this complication

Answer 36

<ul> <li>Patient Factors:</li> <ul> <li>Obesity</li> <li>Decreased BMD</li> <li>Inflammatory arthritis</li> <li>Female gender (2x)</li> </ul> <li>Intra-operative (85% of fractures)</li> <ul> <li>Notching of femoral neck</li> <li>Excessive prosthesis varus (<130O)</li> <li>Femoral neck cysts</li> <li>Improper implant seating</li> </ul></ul>

Question 37

RC 2013, 2012 - When standing on one leg, what is the hip joint reaction force? <ol> <li>2.5</li> <li>4.5</li> <li>6.5</li> <li>8.5</li></ol>

Answer 37

<div>ANSWER: A</div>

<ul> <li>2012, 2013</li> <li>Journal of Biomechanics (2001) - Hip contact forces and gait patterns from routine activities </li> <ul> <li>The average peak forces of the patients during normal walking at about 4km/h were between 211and 285% bodyweight.</li> </ul></ul>

Question 38

RC exam - When putting in screws into the acetabulum and going into the safe posterosuperior zone, what is at risk? <ol> <li>Obturator NV bundle</li> <li>External iliac</li> <li>Superior gluteal NV bundle</li> <li>Inferior gluteal NV bundle</li></ol>

Answer 38

“C.<div><br></br></div><div><img></img><br></br></div>”

Question 39

<div>RC 2014 - In order to determine the acetabular safe zone for screw placement, a line is drawn from where to where?</div>

<ol> <li>AIIS to center of acetabulum</li> <li>ASIS to center of acetabulum</li> <li>Ischial tuberosity to center of acetabulum</li> <li>Cannot remember the last option</li></ol>

Answer 39

“B.<div><br></br></div><div><img></img><br></br></div><div><img></img><br></br></div>”

Question 40

<div>RC 2014 - When pre-op planning for a THA, the femoral mechanical axis is?</div>

<ol> <li>A line drawn through the centre of the femoral head to 1.5 cm medial to center of knee</li> <li>A line drawn through the centre of the femoral head to 1.5 cm lateral to center of knee</li> <li>A line drawn through the centre of the femoral head and intersecting the anatomic axis at the intercondylar notch</li> <li>A line bisecting the medullary canal</li></ol>

Answer 40

C.

Question 41

<div>RC 2011 - Stability of THA reduced by?</div>

<ol> <li>larger head</li> <li>smaller head</li> <li>troch bursitis secondary to altered soft tissue tension</li> <li>position of cup at 40 degrees inclination and 15 degrees anteversion</li></ol>

Answer 41

B.

Question 42

RC 2016 - What can be expected following trochanteric advancement which creates relative neck lengthening? <ol> <li>Abductor weakness</li> <li>Reduces trendelenberg gait</li> <li>Will cause a limp</li> <li>Increased joint reaction forces</li></ol>

Answer 42

“B.<div><ul> <li>Miller’s Review p383</li> <ul> <li>By advancing greater trochanter distally, the abductor complex is tensioned tighter, which increases hip compression forces</li> </ul></ul></div>”

Question 43

<div>RC 2014, 2013, 2011 - What are 5 potential complications from a mal-positioned acetabular component?</div>

Answer 43

<ul> <li>Instability/Dislocation</li> <li>Impingement</li> <li>Aseptic Loosening</li> <li>Bearing surface wear/pelvic osteolysis</li> <li>Revision Surgery</li> <li>Psoas Irritation</li> <li>Leg Length Discrepancy</li></ul>

Question 44

<div>RC 2014 - In a patient with acetabular dysplasia, which position will provoke anterior instability?</div>

<ol> <li>Flexion and internal rotation</li> <li>Flexion and external rotation</li> <li>Extension and internal rotation</li> <li>Extension and external rotation</li></ol>

Answer 44

D.<div><br></br></div><div><ul> <li>Hip Instability. Smith and Sekiya. Sports Med Arthrosc Med 2010.</li> </ul> <ul> <li>The iliofemoral ligament (Y-ligament of Bigelow) is the strongest hip capsule ligament. It lies anterior to the femoral head and helps to resist anterior translation during external rotation and extension. </li> <li>For anterior dislocations, patients should refrain from hip hyperextension and external rotation for 6 weeks. </li> </ul> <div>As anterior capsular ligaments become lax, the hip will externally rotate well beyond the resting position with minimal resistance, often asymmetric to the contralateral side. In addition, patients may develop a feeling of apprehension with hip hyperextension and external rotation.</div></div>

Question 45

<div>RC 2014 - What can be done to increase the primary arc of motion in a total hip arthroplasty?</div>

<ol> <li>Use a larger head</li> <li>Placing a collar on the femoral neck</li> <li>Increasing the offset</li> <li>Increasing the acetabular anteversion</li> </ol>

<div></div>

Answer 45

“A.<div><ul> <li>Primary Arc Range is controlled by the head/neck ratio:</li> <ul> <li>Best stability is achieved by maximizing head/neck ratio</li> <li>Things that decrease arc range:</li> <ul> <li>Neck skirt (femoral head collar)</li> <li>Acetabular hood</li> <li>Constrained cups</li> </ul> </ul> </ul> <div></div> <div><img></img></div></div>”

Question 46

RC 2012 - When are you more likely to injure the superior gluteal nerve? <ol> <li>Glut med split with Hardinge approach</li> <li>Retractor placement with Kocher Langenbach</li> <li>When doing a GT osteotomy</li></ol>

Answer 46

“A.<div><ul> <li>Superior gluteal nerve innervates Glut med, glut min, and TFL</li> <li>The superior gluteal nerve runs between the glut medius and glut minimus about 5 cm above the GT. During your approach to the hip it can be damaged if you do not limit your glut medius dissection</li> </ul> <div></div> <ul> <li><img></img></li> </ul> <div>Wheeless</div> <ul> <li>place a tagging suture 5 cm above the greater trochanter</li></ul></div>”

Question 47

<div>RC 2015 - What is the most common nerve injury associated with the Hardinge approach for a THA?</div>

<div> a. Sciatic </div>

<div> b. Inferior gluteal</div>

<div> c. Superior gluteal</div>

<div> d. Femoral</div>

Answer 47

C.

Question 48

<div>RC 2013 - The most common nerve injured during THA is:</div>

<ol> <li>Sciatic (peroneal division)</li> <li>Obturator</li> <li>Superior Gluteal Nerve</li> <li>Femoral Nerve</li></ol>

Answer 48

A.<div>nerve injury ~1%</div><div><br></br></div><div><ul> <li>Injured w/ posterior acetabular retractor placement</li> <li>Injured w/ anterior or lateral traction on the femur</li> <li>The sciatic nerve is the nerve most commonly injured during THA. It was involved in over 90% of the 53 nerve injuries reported by Schmalzried et al in their series of more than 3,000 cases.</li> <li>The peroneal division of the sciatic nerve is more susceptible to injury than the tibial division. Schmalzried et al found that 94% of the sciatic nerve injuries in their study involved the peroneal division. The peroneal division may be more susceptible to stretch injuries because it is relatively more fixed between the sciatic notch and the fibular head as well as the density of the fibers within the nerve</li></ul></div>

Question 49

RC 2009 - Sciatic nerve in THA. All of the following except: <ol> <li>Most completely recover</li> <li>70% have subclinical EMG changes</li> <li>more common in females</li> <li>more common in revisions</li></ol>

Answer 49

A.<div><br></br></div><div><div>Only 36% had complete recovery at 21 months</div></div>

Question 50

<div>RC 2018 - A new biomaterial has been designed for hard on soft bearings in total hip arthroplasty. Which method would most accurately evaluate wear between the two materials? (question very similar to that seen on Orthobullets)</div>

<div>a.immediate post-operative radiographs compared to annual follow-up radiographs</div>

<div>b.comparing each material with radiostereometric analysis</div>

<div>c.comparing each material with annual CT scans</div>

<div>d.comparing each material with computer-assisted edge-detection radiographs</div>

Answer 50

B.<div><br></br></div><div>radiostereometric analysis (RSA)</div>

Question 51

RC 2015 - What is a disadvantage of HXPE vs UHMWPE: <ol> <li>Decreased fracture</li> <li>Decreased oxidization</li> <li>Increased cost</li> <li>Decreased wear</li></ol>

Answer 51

C.<div><br></br></div><div><div>XLPE is two to four times the cost of conventional PE without an improvement in clinical or radiographic outcomes.</div><ul> <li>In vitro studies:</li> <ul> <li>Reduced fracture toughness</li> <li>Reduced resistance to fatigue crack propagation</li> <li>Smaller particle generation which is possible more biologically active</li> </ul></ul><div></div></div>

Question 52

<div>RC 2011 - Metal on poly total hip. What is the most common cause of wear?</div>

<ol> <li>Mode 1</li> <li>Mode 2</li> <li>Mode 3</li> <li>Mode 4</li></ol>

Answer 52

<div>A</div>

<ul> <li>Mode 1 – primary bearing surface to primary bearing surface (1x1)</li> <li>Mode 2 – primary x secondary (2x1=2)</li> <li>Mode 3 – 3rd body</li> <li>Mode 4 – Wear between 2 non bearing surfaces, ie. 2 secondary surfaces (such as backside wear or neck socket impingement) (secondary surface x secondary surface – 2x2=4)</li></ul>

Question 53

<div>RC 2011 - All of these are properties of PMMA except?</div>

<ol> <li>exothermic to 75 degrees</li> <li>stronger in tension than compression</li> <li>does not have adhesive properties to implant</li> <li>Porosity reduction increases strength by 10-15%</li></ol>

Answer 53

B. stronger in compression than tension<div><br></br></div><div><ul> <li>Acts as a grout, not an adhesive</li> <li>Poor tensile and shear strength, strongest in compression</li> <li>Reducing porosity increases cement strength and decreases cracking</li></ul></div>

Question 54

RC 2017 - What is true about the properties of ceramic bearing surfaces <ol> <li>Have an unusually low wear (actual sentence)</li> <li>Have higher third body wear</li> <li>Poor biocompatibility and wettability</li> <li>Must titanium trunion (?)</li></ol>

Answer 54

A.<div><br></br></div><div>D - only true for revision in MoM/trunionosis</div><div><ul> <li>Alumina ceramics are extremely hard and scratch resistant, provide excellent biocompatibility (C not true), have superb chemical and hydrothermal stability as well as an extremely low coefficient of friction, are hydrophilic with superior lubrication, and offer superior wear resistance compared with other available bearing surfaces</li> <li>The major advantages of ceramic-on-polyethylene bearings include hardness, scratch resistance, a lower coefficient of friction compared with other available bearings, increased wettability for improved lubrication, and superior wear resistance. In the presence of third-body wear, their scratch resistance offers a further advantage over cobalt-chromium heads (B not true).</li></ul></div><div><br></br></div>

Question 55

<div>RC 2012, 2011 - Which articulation has the least wear? </div>

<ol> <li>large head metal on metal</li> <li>small head metal on metal</li> <li>head on crosslinked poly</li> <li>ceramic on ceramic</li></ol>

Answer 55

D.<div><ul> <li>Ceramic bearings have the lowest wear rates of any bearing combination (0.5 to 2.5 µ per component per year)</li> <li>ceramic-on-polyethylene bearings have varied, ranging from 0 to 150 µ</li> <li>MoM form smaller wear particles vs MoP (2.5 to 5.0 µ per year) and have less wear than MoP, but still more wear than CoC</li> <li>MoM higher serum metal ions, lower volumetric wear than MoC</li></ul></div>

Question 56

RC 2013 - 3rd generation cement technique does not include which of the following <ol> <li>Vacuum mixing PMMA</li> <li>Pressurized </li> <li>Use of a cement plug</li> <li>Retrograde filling</li></ol>

Answer 56

“<div>note: vacuum mixing was introduced in 3rd gen</div><div><br></br></div>1 - vacuum mixing MAY not be necessary.<div><br></br></div><div><ul> <li>Third-generation techniques: porosity reduction, pressurization, pulsatile lavage</li> <ul> <li>Although vacuum mixing PMMA is recommended to reduce fumes and reduce porosity of cement, it is not technically included in classical third generation cement techniques</li> </ul></ul><div><img></img><br></br></div></div>”

Question 57

“RC 2008 - Regarding the benefits of tantalum in THA components. All are true except: <ol> <li>More biocompatible than other metals</li> <li>More ingrowth in pores compared to other porous coated metals</li> <li>Greater friction at bone-metal interface</li> <li>Young’s modulus of tantalum more closely approximates bone than that of titanium</li></ol>”

Answer 57

“A.<div><br></br></div><div><ul> <li>All metal has excellent biocompatibility</li> <li>JAAOS 2006 - Applications of Porous Tantalum in THA</li> <ul> <li>High volumetric porosity (70-80%), low modulus of elasticity, high frictional characteristics</li> <li>Excellent biocompatibility</li> <li>Modulus of elasticity similar to that of subchondral bone, but ultimate and yield strength much stronger</li> </ul> </ul> <div></div> <div></div> <div><img></img></div></div>”

Question 58

<div>RC 2015, 2013 - List 4 advantages of using a high offset femoral stem</div>

Answer 58

<ul> <li>Improved ROM</li> <li>Increased stability</li> <li>Decreased impingement of GT on pelvis</li> <li>Improved joint reactive forces - decreased wear/loosening</li> <li>Increased abductor strength/decreased limping</li></ul>

Question 59

<div>RC 2014 - Which situation is best for a constrained acetabular liner in a recurrently unstable THA?</div>

<ol> <li>well-positioned cup with GT nonunion </li> <li>well-positioned cup with absent GT</li> <li>mal-positioned cup with absent GT </li> <li>mal-positioned cup with GT non-union</li></ol>

Answer 59

“B.<div><div>"”the ideal candidate for a constrained device is a low-demand patient who lacks inherent soft-tissue constraint and has either a well-fixed cup suitable for a constrained liner or adequate bone stock for maximal screw fixation of a constrained cup””</div></div>”

Question 60

RC 2015 - What is true regarding modular neck in THA prosthesis: <ol> <li>Decreased notching due to increased varus in the component</li> <li>Increased corrosion</li> <li>Increased osteolysis</li> <li>Increased soft tissue reaction</li></ol>

Answer 60

B.<div><ul> <li>JBJS 2014 - early corrosion-related failure of the rejuvenate modular total hip replacement</li> <li>JAAOS 2016 - Corrosion of the Head-neck Junction after Total Hip Arthroplasty</li></ul></div>

Question 61

RC 2011 - List 4 relative contraindications to total joint arthroplasty.

Answer 61

<ul> <li>Active or remote infection</li> <li>Presence of well-functioning, painless arthrodesis</li> <li>Neuromuscular disease causing potential instability</li> <li>Medically unfit</li> <li>Non-ambulatory patients/lack of active muscle power</li> <li>Active Charcot Neuroarthropathy</li> <li>Asymptomatic Arthritis</li> <li>Insufficient soft tissues</li></ul>

Question 62

RC 2018 Oral - Compare and contrast the pros and cons of each bearing surface for THA?

Answer 62

<ul> <li>Metal on Poly</li> <ul> <li>Pros: Longest track record, cheap, most modularity</li> <li>Cons: trunnionosis, higher wear rate cf the rest</li> </ul> <li>Ceramic on Poly</li> <ul> <li>Pros: good track record, lower wear rate than MoP</li> <li>Cons:</li> </ul> <li>Ceramic on Ceramic</li> <ul> <li>Pros: lowest wear rate, inert particles (no cancer risk)</li> <li>Cons: squeaking, fracture, price</li> </ul></ul>

Question 63

RC 2010 - X-ray with a Crowe 4 hip - The patient is ready to undergo a THA. List 4 things that you have to consider from a technical aspect with regards to the procedure

Answer 63

<ul> <li>Acetabulum:</li> <ul> <li>Increased anteversion</li> <li>Deficient anterosuperiorly</li> <li>Difficulty identifying true acetabulum</li> <li>Deficient bone stock</li> </ul> <li>Femoral Side:</li> <ul> <li>Increased anteversion</li> <li>Small diameter canal</li> <li>Increased anterior bow of femur</li> <li>Valgus neck shaft angle</li> </ul> <li>Soft Tissues:</li> <ul> <li>Tensioning of sciatic nerve by leg lengthening</li> <ul> <li>May need femoral shortening osteotomy</li> </ul> <li>Contracted, deficient abductors</li> </ul></ul>

Question 64

RC 2016-2013 - What are 5 factors to consider preop that suggest poor prognosis when considering a pelvic osteotomy in adult developmental dysplasia of the hip?

Answer 64

“<ul> <li>Patient Factors</li> <ul> <li>Older Age</li> <li>Asymptomatic dysplasia</li> <li>Non-ambulatory</li> <li>Loss of ROM</li> <li>Morbid obesity (relative)</li> </ul> </ul> <ul> <li>Radiographic</li> <ul> <li>Tonnis Grade 2/3 OA</li> <li>Pre-op CEA<0, coronal CEA <5</li> <li>Incongruent Abd-IR (Van Rosen)</li> <li>Os-acetabuli (calcified labrum)</li> </ul></ul><div><img></img><br></br></div>”

Question 65

<div>RC 2014, 2010 - X-ray of a hip with cystic changes and sclerosis (AVN). Give 3 common causes for this disease process.</div>

Answer 65

“<ul> <li>Patient Factors: </li> <ul> <li>Renal Failure</li> <li>SLE</li> <li>Post-transplant</li> <li>Radiation therapy</li> <li>Hematologic Disorder (sickle cell, hypofibrinolysis, thrombophilia)</li> <li>Dysbarism</li> <li>Storage Diseases (Gaucher’s)</li> </ul> <li>Drugs: Steroids, EtOH</li> <li>Trauma: femoral neck/head fracture, dislocation</li></ul>”

Question 66

RC 2011 - What is the most predictable treatment of a femoral head with AVN of femoral head that already shows collapse? <ol> <li>arthroplasty</li> <li>core decompression</li> <li>fibular allograft</li> <li>bisphosphates</li></ol>

Answer 66

A.

Question 67

RC ORAL: options for tx in collapsed AVN

Answer 67

<ol> <li>Total hip arthroplasty </li> <ol> <li>Pros: most reliable, early weight bearing</li> <li>Cons: will need revision in future given young age, relatively higher rate of dislocation</li> </ol> <li>Hip resurfacing</li> <ol> <li>Pros: preserves bone stock</li> <li>Cons: childbearing age - technically a contraindication, same with AVN</li> </ol> <li>Flexion osteotomy</li> <ol> <li>Cons: already complete collapse --> precludes this option; may make future THA more difficult if </li> </ol> <li>Bipolar</li> <ol> <li>Cons: too young, will destroy acetabular cartilage and need revision to THA</li> </ol></ol>

Question 68

RC 2008 - Chiari Osteotomy now needs a THA, what is the challenge of THA? <ol> <li>Move GT distally</li> <li>Move GT laterally</li> <li>Acetabular exposure</li> <li>Over reaming of anterior and posterior walls</li></ol>

Answer 68

“C.<div><br></br></div><div><img></img><br></br></div>”

Question 69

RC ORAL - Revision components in THA?

Answer 69

“<div><b><u>Acetabulum</u></b></div><div>-““hemispherical uncemented porous-coated multi hole cup, secured with screws””</div><div>-bone graft</div><div>-metal augments (bilobed cup)</div><div>-cup-cage construct</div><div>-ORIF of pelvic discontinuity</div><div><br></br></div><div><b><u>Femur</u></b></div><div>-long diaphyseal engaging, highly porous-coated</div><div>-modular tapered stem (better than modular cylindrical stems!)</div><div>-impaction grafting (must use cemented stem)</div><div>-Allograft prosthetic composite</div><div>-PFR/megaprosthesis</div><div><br></br></div>”

Question 70

RC 2012 - 70 yo with cemented (cup and stem) THA 15 years ago presents with worsening activity-related pain gradually over 2 year period. No constitutional symptoms, otherwise healthy. ESR and CRP are normal. X-ray shows loose acetabular component only. What further workup is indicated before proceeding to revision THR? <ol> <li>Bone scan</li> <li>WBC Scan</li> <li>Aspiration and nuclear med</li> <li>Nothing</li> </ol> <div></div>

Answer 70

D. If both CRP and ESR are normal then negative predictive value for infection is 100%<div><br></br></div>

Question 71

RC 2016, 2015 - What is the most common reason for revision in THA? <ol> <li>Instability</li> <li>Infection</li> <li>Pain</li> <li>LLD</li></ol>

Answer 71

“A.<div><img></img><br></br></div>”

Question 72

RC 2015 - 56 yo male with THA complains of groin pain. Pain with circumduction and resisted flexion on exam. XRAY shows abducted cup - what do you do? <div> a. Physio</div> <div> b. WBC scan</div> <div> c. Acetabular cup revision +/- psoas release</div> <div> d. Revision of acetabular and femoral components</div>

Answer 72

C.<div><div><br></br></div><ul> <li>Dora C (JBJS Br 2007) Iliopsoas impingement after THA: The results of non-operative management, tenotomy or acetabular revision</li> <ul> <li>Review of 30 hips with well-fixed but mal-positioned or over-sized cups and iliopsoas tendonitis</li> <li>86% of patients with surgery had improvement</li> <li>Conservative management failed in all cases</li> <li>No benefit between tenotomy and acetabular revision at 2 years, revision had higher initial complications</li> </ul> <li>JAAOS 2009 - Anterior Iliopsoas Impingement and Tendinitis after THA</li> <ul> <li>Non-surgical treatment successful in only 39% of cases in our literature review</li> </ul></ul></div>

Question 73

RC 2014, 2010 - 70 yr old with cemented 15 yr THA, 1 yr history of thigh pain and periprosthetic fracture. List 3 factors important in the surgical management.

Answer 73

<ul> <li>Vancouver Classification:</li> <ul> <li>Location of fracture</li> <li>Stability of implant</li> <li>Bone stock available</li> </ul> <li>Other:</li> <ul> <li>Pre-operative medical optimization/function</li> <li>Abductor deficiency (constraint)</li> <li>Acetabular component stability (dual revision)</li> <li>Previous components</li> </ul></ul>

Question 74

RC 2012 - 6 causes for groin pain and decreased function in a THA

Answer 74

<ul> <li>Intrinsic Hip</li> <ul> <li>Infection</li> <li>Aseptic loosening of acetabular component/Pelvic osteolysis</li> <li>Dislocation/instability</li> <li>Synovitis secondary to wear debris</li> <li>Periprosthetic fracture</li> <li>Pseudotumor</li> <li>Heterotopic ossification</li> </ul> <li>Extrinsic</li> <ul> <li>Hernia</li> <li>Psoas tendonitis</li> <li>Stress fracture of pelvis</li> <li>Lumbar spine disease</li> <li>GU/Gyne/Abdo</li> </ul></ul>

Question 75

RC Oral - Principles of Mx for pelvic discontinuity?

Answer 75

-restore column continuity (illium to ischium - plate PC)<div>-bone graft the defect</div><div>-Maximize native bone and implant contact for stability</div>

Question 76

<div>RC 2016, 2014, 2012 - List 4 radiographic findings in considering adult FAI?</div>

Answer 76

<ul> <li>Cam: (no good cut off evidence)</li> <ul> <li>DECREASED head-neck offset (<8-9mm)</li> <li>Alpha angle > 55-60o </li> <li>Pistol Grip Deformity</li> <li>Triangular index>1</li> </ul> <li>Pincer:</li> <ul> <li>Acetabular Retroversion:</li> <ul> <li>Cross-over sign</li> <li>Ischial spine sign</li> <li>Posterior Wall Sign</li> </ul> <li>Global Overcoverage:</li> <ul> <li>Lateral CEA > 40o</li> <li>Down-sloping sourcil</li> <li>Coxa profunda</li> <li>Protrusio acetabuli</li> <li>Tonnis angle < 0o</li> </ul> </ul></ul>

Question 77

RC 2013 - Youngish patient has hip pain. What is NOT true: <ol> <li>L1 radiculopathy</li> <li>Retroverted acetabulum causing Pincer impingement</li> <li>Shape of femoral head is normal in CAM impingement</li> <li>Impingement related hip pain typically occurs when seated for long periods or after activity.</li></ol>

Answer 77

C.

Question 78

<div>RC 2015 - What are 3 cause of impingement in the hip other than FAI?</div>

Answer 78

<ul> <li>Blankenbaker DG (Semin Musc Radiol 2013) Non-Femoral Acetabular Impingement</li> </ul>

<ol> <li>Ischiofemoral Impingement Syndrome</li> </ol>

<ul> <li>Narrowing between ischial tuberosity and LT --> QF gets pinched</li> </ul>

<li>Anterior Inferior Iliac Spine/Sub-spine Impingement Syndrome</li>

<ul> <li>Abnormal contact between AIIS and proximal femur</li> </ul>

<li>Iliopsoas Impingement Syndrome</li>

<ul> <li>Thickened or taut psoas at acetabular rim/anterior hip capsule</li> </ul>

Question 79

<div>RC 2008 - Least likely to have HO after THA</div>

<ol> <li>Pagets</li> <li>Females under 65</li> <li>Ankylosing Spondylitis</li> <li>Cementless Implants</li></ol>

Answer 79

B.<div><br></br></div><div>JAAOS</div><div><ul> <li>Risk factors:</li> </ul><ol> <li>high risk</li> <ol> <li>men with bilateral hypertrophic OA</li> <li>history of HO in either hip</li> <li>post-traumatic arthritis characterized by hypertrophic osteophytosis</li> </ol> </ol> <ol> <li>moderate</li> <ol> <li>ankylosing spondylitis</li> <li>DISH</li> <li>Paget’s</li> <li>Unilateral hypertrophic OA</li> </ol> </ol> <ol> <li>Men > women</li> <li>Cementless femoral component</li> <li>Approach: extended iliofemoral > Kocher > ilioinguinal</li> </ol></div>

Question 80

RC 2008 -HO and TKA, risk factors - all of the following except <ol> <li>Femur Notching</li> <li>RA</li> <li>Manipulation post-op</li> <li>Female with hypertrophic osteoarthropathy</li></ol>

Answer 80

B.<div><ul> <li>Patients at high risk for developing HO after TKA include those with limited post-op knee flexion, increased lumbar BMD, hypertrophic arthrosis, excessive periosteal trauma, notching of the anterior femur, those who require forced manipulation after TKA</li></ul></div>

Question 81

RC 2008 - THA and hemophilia, all of the following except: <ol> <li>Replace factors to 100%</li> <li>Coxa valga</li> <li>Infection rate similar to non-hemophiliac patients</li> <li>HO rate is decreased</li></ol>

Answer 81

C.<div><br></br></div><div><div><ul> <li>Two hours pre-op replace factor level to 100% with IV infusion</li> <ul> <li>Check for factor level with factor assay</li> </ul> <li>Intra-operative- keep factor at >60%</li> <li>Post-operative in hospital- keep factor at >60% until discharge</li> <ul> <li>Recheck levels every 1-2 days</li> </ul> <li>Post-operative at home- keep factor at 30-60% normal level for 2 weeks post-op</li></ul></div> <div><br></br></div> <ul> <li>coxa valga is true in haemophiliac</li> <li>Knee>elbow>ankle>hip</li> <li>Higher risk late infection,…..yrs down the road</li> <li>Early infection rate no difference</li></ul></div>

Question 82

<div>RC Exam - THA and Sickle Cell anemia - all of the following except:</div>

<ol> <li>Must cover salmonella</li> <li>Increased dislocation rate</li> <li>Increased early revision</li> <li>Increased deep infection</li></ol>

Answer 82

A. no risk of salmonella in THA<div><br></br></div><div><ul> <li>Pre-op considerations:</li> <ul> <li>Pre-op osteomyelitis</li> <ul> <li>Intra-op bone cultures</li> <li>Other sources of infection often present (Sickle patients often get transient bacteremia)</li> </ul> <li>Avoid sickle cell crisis (lots of fluids, oxygenate, avoid acidosis)</li> <li>CHF often present with chronic anemia</li> <li>Pre-op transfusions/plasmapheresis</li> </ul> <li>Intra-op:</li> <ul> <li>Protrusio</li> <li>Widened canal – marrow hyperplasia</li> <li>Poor bone quality/multiple infarcts</li> <li>osteonecrosis</li> </ul> <li>Rule out other infections pre arthroplasty because patients with sickle cell hemoglobinopathies suffer from an unusually high infection rate related to functional asplenia.</li> <li>Post-op:</li> <ul> <li>THA infection rate between 16% and 20%</li> <li>Although the complication rate has been reported to be as high as 80% at 6-year follow-up and the revision rate as high as 63% at 6.5 years postoperatively, no reports of salmonella osteomyeltitis in sickle cell THA; don’t need coverage for salmonella (gram negative)</li> <li>Higher rate of hip dislocation – up to 26%</li> </ul></ul></div>

Question 83

RC 2012 - All are cause of snapping hip EXCEPT: <ol> <li>IT band</li> <li>Iliopsoas</li> <li>Hamstring</li> <li>Labrum</li></ol>

Answer 83

C.<div><br></br></div><div>coxa saltans<div><br></br></div><div><ul> <li>External Type:</li> <ul> <li>IT Band over GT</li> <li>Snaps going from hip flexion to extension</li> </ul> <li>Internal Type:</li> <ul> <li>Iliopsoas over iliopectineal eminence</li> <li>Snaps going from hip extension to flexion</li> </ul> <li>Intra-articular:</li> <ul> <li>Loose body</li> <li>Acetabular labrum - Usually posterosuperior labrum</li></ul></ul></div></div>

Question 84

<div>RC 2017 - Name 4 risk factors for infection with total hip arthroplasty</div>

Answer 84

<ul> <li>Patient factors</li> <ul> <li>Obesity BMI >30</li> <li>DM</li> <li>Post traumatic arthritis</li> <li>Chronic liver disease</li> <li>Glucocorticoid use, RA</li> <li>EtOH abuse</li> <li>Drug abuse</li> <li>Poor nutritional status (Albumin<5)</li> </ul> <li>Surgical factors</li> <ul> <li>Prolonged surgical time</li> <li>Prolonged wound drainage</li> <li>Hematoma</li> </ul></ul>

Question 85

RC 2014 - All have been shown to decrease infection in TKA EXCEPT? <ol> <li>Antibiotic loaded cement</li> <li>Shorter operating time</li> <li>Lower BMI</li> <li>Irrigation</li></ol>

Answer 85

A.<div>Bohm E (CORR 2014) Does adding antibiotics to cement reduce the need for early revision in total knee arthroplasty?</div><div>Canadian registry data: No significant difference within 2 years<br></br></div>

Question 86

RC 2016 - A patient presents with worsening knee pain, swelling erythema over the last 2 weeks following dental extraction. TKA 10 years ago. Inflammatory markers elevated. What is the most appropriate NEXT step: <ol> <li>Single stage revision</li> <li>Two stage revision</li> <li>I&D and liner exchange</li> <li>I&D</li></ol>

Answer 86

C.<div><ul> <li>2016 J of Arthroplasty Is there still a role for irrigation and debridement with liner exchange in acute periprosthetic total knee infection?</li> <ul> <li>They did liner exchange with extensive I+D in patients with acute infections (few than 3 weeks of symptoms and no immune compromise)</li> <li>Found that for all commers, irradication rate was 68.66%. If pseudamonas (66.67% failure rate) and MRSA (80% failure rate) were removed, success of I+D with liner exchange was raised to 85.25%</li> </ul></ul></div>

Question 87

<div>RC 2018 - A patient of yours shows up in clinic. He underwent an uncomplicated THA 2 weeks ago. He is otherwise healthy. He did well and discharged without incident on post op day 2. By post op day 7 he developed increased pain and drainage from his wound. You are seeing him in the office at routine 2 week follow up. What is the best management strategy?</div>

<div>a.Admit to hospital and take to OR for I+D, component retention, and polyethylene exchange</div>

<div>b.Admit to hospital for 6 weeks of IV antibiotics</div>

<div>c.Two-stage revision</div>

<div>d.Prescribe a 10 day course of oral antibiotics</div>

Answer 87

A.<div><br></br></div><div>2016 J of Arthroplasty Is there still a role for irrigation and debridement with liner exchange in acute periprosthetic total knee infection? They did liner exchange with extensive I+D in patients with acute infections (few than 3 weeks of symptoms and no immune compromise) Found that for all commers, irradication rate was 68.66%. If pseudamonas (66.67% failure rate) and MRSA (80% failure rate) were removed, success of I+D with liner exchange was raised to 85.25%<br></br></div>

Question 88

“RC 2018 - A 45 year old male presents to your clinic with LEFT sided hip pain for several weeks. His XR is pictured below. List 3 common causes for this condition. (Ben’s note: Not exact XR on exam but pretty similar) <div></div> <div><img></img></div>”

Answer 88

“<div><ul><li>Patient Factors:</li><ul><li>Renal Failure</li><li>SLE</li><li>Post-transplant</li><li>Radiation therapy</li><li>Hematologic Disorder (sickle cell, hypofibrinolysis, thrombophilia)</li><li>Dysbarism</li><li>Storage Diseases (Gaucher’s)</li></ul><li>Drugs: Steroids, EtOH</li><li>Trauma: femoral neck/head fracture, dislocation</li></ul></div><ul><ul> </ul></ul>”

Question 89

RC 2018 - List 5 ways to manage acetabular bone loss in the setting of revision total hip arthroplasty.

Answer 89

“<ol> <li><img></img></li> </ol> <ul> <li>Impaction bone graft</li> <ul> <li>Simple cavitary defects</li> <li>Can augment segmental defects when using metal to convert to a contained defect</li> </ul> <li>Non-cemented Hemispheric Cup</li> <ul> <li>Preferred method in Type 1 and.2 defects</li> <li>Requires column and partial rim support</li> </ul> <li>Structural autograft</li> <ul> <li>Not an option, no longer have a femoral head</li> </ul> <li>Structural allograft</li> <ul> <li>Goal to give bony support for non-cemented cup</li> <li>Femoral head, distal femur, total acetabulum</li> </ul> <li>Porous modular metal implants/augments</li> <ul> <li>Goal to put in uncemented cup </li> <li>Usually srew it to the bone, then cement the cup to the augment (it is a noncemented cup though)</li> <li>Then bone graft</li> </ul> <li>Cup cage construct</li> <li>Triflange custom cup </li> <li>Oblong Cup</li> <li>Ring Cage Construct </li></ul>”

Question 90

RC 2018 - In patients who have had a THA and a TKA in the same limb, it is possible to have a periprosthetic fracture between the two implants. In this situation, list 4 principles of management.

Answer 90

<div></div>

<div>Scolaro et al. Management of Interprosthetic Femur Fractures. JAAOS 2017 Apr<br></br></div>

<div></div>

<ol> <li>Ensure stability of implants or revise to stable implants</li> <li>Preserve endosteal femoral blood supply</li> <li>Bypass stems by minimum 2 cortical widths:</li> </ol>

<ul> <li>Plate should span most if not entire length of femur</li> </ul>

<ol> <li>Use screws AND cerclage wires</li> <li>Screws can be placed into cement mantle</li> </ol>

<li>Augment with allograft / autograft / interprosthetic sleeves</li>

<li>Fixed angle devices</li>

Question 91

<div>RC 2018 - When doing a PCL-sacrificing total knee arthroplasty which is true?</div>

<ol> <li>can raise joint line 12mm </li> <li>resection of PCL increases flexion arc 3-5mm</li> <li>better ROM postop with PCL retaining (or vice versa)</li> <li>better long term outcome with PCL-sacrificing (or maybe retaining)</li></ol>

Answer 91

“B.<div><br></br><div><div>o PCL retaining knees have better survival</div><div> o Slightly better ROM with sacrificing –> but not clinically significant</div> o All patients getting arthroplasty have slight elevation of joint line, but no difference between implant types<br></br></div></div><div><b>"”After releasing the PCL, the medial gap in extension increased by 1.2 mm, the lateral gap in extension increased by 0.3 mm, the medial gap in flexion increased by 4.5 mm, and the lateral gap in flexion increased by 3.4 mm.””</b><br></br></div>”

Question 92

<div>RC 2018 - Shown a picture of a TKA with a periprosthetic femur fracture treated with a lateral plate 5 years ago. Now, presents with another fracture, for which you are considering a retrograde nail. Why would you like to have the previous OR reports? (exact answers)</div>

<ol> <li>Approach</li> <li>Tourniquet time</li> <li>Implant type and manufacturer</li> <li>To know whether the TKA has an anterior notch</li></ol>

Answer 92

C.

Question 93

“<div>RC 2018 - 30 year old with groin pain. Shown an image of a hip with what I thought looked like extensive synovial chondromatosis (?) / chondrocalcinosis. No arthritic changes. How should you manage this?</div> <div><img></img></div> <ol> <li>Surgical hip dislocation and synovectomy</li> <li>Chemotherapy and resection</li> <li>Radiation and resection</li> <li>Total hip arthroplasty</li></ol>”

Answer 93

A. WOULD PICK ARTHROSCOPIC IF IT WAS AN ANSWER<div><br></br></div><div><ul> <li>For example, a patient with synovial chondromatosis of the hip treated at our institution would undergo arthroscopic removal of loose bodies and arthroscopic synovectomy. He or she would not undergo open arthrotomy and surgical hip dislocation purely to facilitate a total synovectomy</li> <li>See notes</li> <ul> <li>More complications with dislocation </li> <li>Less recurrence with dislocation</li> <li>Arthroscopy technically challenging, cant access extra articular disease</li> </ul></ul></div>

Question 94

<div>RC 2018 - Which of the following is NOT true regarding RFs for metal sensitivity?</div>

<div>a.Male</div>

<div>b.Ear piercing</div>

<div>c.Hand eczema</div>

<div>d.Smoking hx</div>

Answer 94

“A.<div><br></br></div><div><div>JAAOS Metal Hypersensitivity in TKA 2016</div> <div>Most sensitive metals - nickel > cobalt > chromium</div> <ul> <li>10-15% in general population</li> <li>Generally Type 4 allergic reaction</li> <ul> <li>Delayed cell mediated with T lymphocytes</li> </ul> <li>Clinical Syndrome</li> <ul> <li>Dermatitis</li> <ul> <li>Eczema, usually on the knee but ca include whole body</li> </ul> </ul> </ul> <div></div> <div>JAAOS Allergic or Hypersensitivity Reactions in Ortho Implants 2017</div> <ul> <li><img></img></li></ul></div>”

Question 95

“RC 2013, 2008 -Picture of Short External rotators. What is the vertical line coming from the bottom of the picture pointing to? <div><img></img></div> <div>a. Obturator internus</div> <div>b. Obturator externus</div> <div>c. Superior gemelli</div> <div>d. Inferior gemelli</div>”

Answer 95

“A. OI.<div><br></br></div><div><img></img><br></br></div>”

Question 96

RC 2017 -<b>All are risk factors for Osteonecrosis of femoral head except</b> <div><b>a. </b><b>Corticosteroid use</b></div> <div><b>b. </b><b>Caissons disease</b></div> <div><b>c. </b><b>Trauma</b></div> <div><b>d. </b><b>Hemophilia A</b></div> <div></div>

Answer 96

D.<div>Pathogenic Mechanisms for Osteonecrosis<br></br></div><div> <div>· Ischemia –> femoral neck fracture, dislocation, surgery</div> <div>§ Vascular compression</div> <div>· Corticosteroids</div> <div>· Alcohol</div> <div>· Thrombosis/thrombophilias</div> <div>· Embolization with fat or air</div> <div>· Sickle cell occlusion</div> <div>· Cellular toxicity –> drugs, radiation, oxidative stress</div></div>

Question 97

“All are true about TXA, except? (RC 2019)<div>A. Liver excretes it, so it doesn’t require renal dosing</div><div>B. Prevents fibrinolysis and clotting degradation</div><div>C. Can be taken PO, IV, topical</div><div>D. Causes blurred vision and colour blindness</div>”

Answer 97

“Ans: A<div><br></br></div><div><div><span>Ref: </span><span>JAAOS 2015 23(12) 732-740</span></div><ul><li><div><span>TXA is a synthetic drug that limits blood loss through </span><span>inhibition of fibrinolysis</span><span> and </span><span>clot degradation</span><span>.</span><span></span></div></li><li><div><span>Surgical trauma is known to cause fibrinolysis, which increases with the use of a pneumatic tourniquet.</span></div></li><li><div><span>TXA reversibly saturates the </span><span>lysine binding site of plasminogen</span><span>, preventing the interaction of the active protease, plasmin, with the surface-binding site on fibrin.</span></div></li></ul><ul><li><div><span>This inhibits the degradation of a fibrin clot by plasmin.</span></div></li></ul><ul><li><div><span>TXA is available in IV, topical, and oral forms</span></div></li></ul><ul><li><div><span>Requires renal dosing</span></div></li></ul><ul><li><div><span>Recommend 10-20mg/kg dose pre-incision and 3 hrs later to reduce bleeding, transfusion</span></div></li></ul><br></br><div><span>Ref: </span><span>Drugs.com</span></div><ul><li><div><span>Can cause changes to vision/blurriness</span></div></li></ul><ul><li><div>Rare occurrences of changes to color vision, retinal artery occlusion, central retinal artery/vein obstruction</div></li></ul></div>”

Question 98

<div>What is true of hemophilia?</div>

<ol><li><div>Hemo A is IX deficiency</div></li><li><div>X-Linked recessive</div></li><li><div>Females never get it</div></li><li><div>There is a usually spontaneous occurrence</div></li></ol>

Answer 98

“<br></br><br></br><div>Answer: B</div><br></br><div><span>Ref: Musculoskeletal Care of the Hemophiliac Patient. JAAOS 2012</span></div><ul><li><div>Hemophilia is caused by a deficiency of clotting factor VIII or IX and is inherited by a<span></span><span>sex-linked recessive</span><span></span>pattern.</div></li><li><div>von Willebrand disease, a common, moderate bleeding disorder, is caused by a quantitative or qualitative protein deficiency of von Willebrand factor and is inherited in an<span>autosomal dominant or recessive manner.</span></div></li><li><div>Inheritence pattern</div></li><ul><li><div>Congential hemophilia</div></li><ul><li><div>X-linked recessive<span>disorder (</span>typically<span></span>affects<span>males only</span><span>)</span></div></li></ul><li><div>Aquired hemophila</div></li><ul><li><div>Rare condition with autoimmune ethiology, with no genetic inheritance</div></li></ul></ul></ul>”

Question 99

“What is the benefit of pre-hab before arthroplasty? (RC 2019)<div>A. Improved quads strength</div><div>B. Improved hamstring strength</div><div>C. No improvement in length of stay</div><div>D. Increases patient anxiety-pre-op</div>”

Answer 99

“Answer: A<div><div><div><span><br></br></span></div><div><span>Ref: Moyer R, et al. The Value of Preoperative Exercise and Education for Patients Undergoing Total Hip and Knee Arthroplasty: A Systematic Review and Meta-Analysis. JBJS Rev. 2017;5(12):e2.</span></div><ul><li><div>Patients undergoing TKA, significant improvements were observed for <span>function, quadriceps strength, and length of stay.</span></div></li></ul><br></br><div><span>Ref: Wang L, et al. Does preoperative rehabilitation for patients planning to undergo joint replacement surgery improve outcomes? A systematic review and meta-analysis of randomized controlled trials. </span><span>BMJ Open. 2016 Feb 2;6(2):e009857.</span></div><ul><li><div>Existing evidence suggests that pre-habilitation may slightly improve early postoperative pain and function among patients undergoing joint replacement; however, effects remain too small and short-term to be considered clinically-important, and did not affect key outcomes of interest (ie, length of stay, quality of life, costs).</div></li></ul></div></div>”

Question 100

“What is true regarding TTO in revision TKA? (RC 2019)<div><span><br></br></span></div><div><span>A. Low union rate</span></div><div><span>B. Low complication rate</span></div><div><span>C. Cannot be used in a primary knee</span></div><div><span>D. Requires good bone stock (>2.5cm anteriorly)</span></div>”

Answer 100

“<div><span>Answer: B</span></div><br></br><div>Ref: JBJS Essent Surg Tech. 2016 Sep 28; 6(3): e32.</div><h3><span>Indications</span></h3><ul><li><h3><span>Difficult knee exposure during revision (or primary) TKA.</span></h3></li><ul><li><h3><span>The TTO is most commonly needed in cases of arthrofibrosis or patella baja.</span></h3></li></ul><li><h3><span>A long tibial stem, cemented or press-fit, that cannot be removed via access to only the tibial plateau-baseplate interface but instead requires access to the tibial stem in the medullary canal to break up the ingrowth and/or cement fixation.</span></h3></li><li><h3><span>The patient </span>must have good bone quality<span> as assessed on radiographs.</span></h3></li><li><h3><span>There must be sufficient thickness of bone stock along the anterior aspect of the tibia </span><span>(≥1.5 cm from the anterior TT to the deepest part of the osteotomy) </span><span>after taking into account the existing cement mantle and tibial keel or stem.</span><span><br></br><br></br></span></h3></li></ul><h3><span>Contraindications</span></h3><ul><li><h3><span>Known osteoporosis (z-score −2.5).</span></h3></li><li><h3><span>Poor bone quality as assessed on radiographs.</span></h3></li><li><h3><span>Insufficient bone stock along the anterior aspect of the tibia.</span></h3></li><li><h3><span>Bone loss requiring reconstruction with a</span> tibial cone<span>, which will restrict fixation of the osteotomized bone fragment.</span></h3></li><li><h3><span>Comorbidities that may impede healing of the osteotomy fragment, such as tobacco use, diabetes, rheumatoid arthritis, and chronic steroid use</span></h3></li></ul><br></br><div><span>Technical Pearls</span></div><ul><li><div>Osteotomy length 8-10 cm <span>(minimum 6 cm)</span></div></li><li><div>Hinge <span>laterally</span>, maintain continuity lateral geniculate blood supply</div></li><li><div>Rigid fixation 6.5 mm bicortical screw proximal, 2x 18g wires distal</div></li><li><div>18 g wires as far posterior as possible to avoid ST Irritation<img></img><img></img></div></li></ul><br></br>A TTO can provide reliable and safe exposure during revision TKA with a high union rate, <span>low complication rate</span>, and predictable outcomes.”

Question 101

What is true regarding anatomic vs. kinematic knee alignment in TKA?<div>A. >3^otibial varus is not associated with increased complications</div><div>B. Cut femur and tibia perpendicular to the anatomic axis</div><div>C. Place the femur in several more degrees of valgus and tibia in several more degrees of varus</div><div>D. Better short and long term outcomes for kinematic knee alignment</div>

Answer 101

“<div><span>Answer: C</span></div><br></br><div><span>Ref: JAAOS 2018</span></div><ul><li><div><span>This step leads to femoral components that are aligned in </span><span>2° to 4° more valgus </span><span>and tibial components that are positioned in </span><span>2° to 4° more varus</span><span>, while maintaining similar hip-knee-ankle angles and anatomic angles of the knee compared to a mechanically aligned knee.”</span></div></li><li><div>Long-term data are still lacking on this alignment technique, and long-term studies with larger numbers are required before making any conclusions regarding this technique.</div></li><li><div>Measured resection relies on 3 different femoral landmarks: posterior condylar axis (PCA), the transepicondylar axis (TEA), and Whiteside line.</div></li><li><div>PCA is<span> most commonly used</span>. Has been noted to be IR 6° relative to the TEA.</div></li><li><div><span>The TEA is typically thought to be the most reliable landmark</span> for assessing femoral rotation and most closely recreates the patient’s natural femoral rotation.</div></li><li><div>The Whiteside line is drawn along the deepest part of the trochlear groove, is perpendicular to the TEA, and<span> has been shown to more consistently approximate appropriate </span><span>external rotation</span><span> compared to the PCA</span>, even in valgus knees.<br></br><br></br></div></li></ul><ul><li><div><span>Patient-specific Instrumentation</span></div></li><ul><li><div>Data supporting the claims for improved alignment, decreased outliers, decreased cost, and decreased blood loss are currently lacking.</div></li></ul></ul><br></br><ul><li><div><span>Computer Navigation</span></div></li><ul><li><div>Active systems typically involve robotic control to perform part of the procedure. Passive systems are more common, and the surgical procedure is entirely under direct surgeon control. <br></br><br></br></div></li></ul><li><div>CAS systems are also distinguished as either image based or image free.</div></li><li><div>Numerous reports exist on the benefits of CAS.</div></li></ul><ul><li><div><span>Meta-analyses have shown improved precision and accuracy in </span><span>coronal alignmen</span><span>t and improved </span><span>femoral rotation</span><span>.</span></div></li></ul><ul><li><div>Use of CAS avoids violation of the femoral or tibial IM canals, which can theoretically decrease blood loss, and the risk of fat emboli syndrome.</div></li></ul><ul><li><div><span>Studies have shown do difference in KSS up to 5 years port-op.</span></div></li></ul><ul><li><div>Other disadvantages: increase OR time and a notable learning curve.</div></li><li><div>Femoral pin site fractures occur at a rate of 1.3% and are more common with transcortical pin placement, and tibial stress fractures can occur as well.</div></li><li><div>Additional costs can be mitigated in high-volume centers performing >250 cases per year.</div></li></ul>”

Question 102

“<div>What reduces the risk of failure in revision arthroplasty?</div><div>A.<span>Retaining cemented prostheses</span></div><div><span>B. Surgery performed by an experienced surgeon</span></div><div><span>C. Young patient age</span></div><div><span>D. Use of metal liner with constrained cup</span></div>”

Answer 102

“<div><span>Answer: B</span></div><br></br><div><span>Ref: Ravi B, et al. Relation between surgeon volume and risk of complications after total hip arthroplasty: propensity score matched cohort study. BMJ 2014;348:g3284.</span></div><ul><li><div><span>In a Canadian study of nearly 38,000 patients, surgeons who performed <35 THAs a year had a dislocation rate of 1.9% vs 1.3% for surgeons with greater volumes.</span></div></li><li><div><span>It has been shown that for every 10 THAs performed, a surgeon’s dislocation rate decreases by 50%.</span></div></li><li><div><span>Institution volume also influences dislocation as demonstrated by a comparison of high- and low-volume centers.</span></div></li></ul><br></br><div><span>Ref: J Orthop. 2019 May 2;16(5):393-395.</span></div><ul><li><div><span>This study reviewed literature published in the last 10 years to investigate the reasons for revision failure.</span></div></li><li><div><span>A total of 9,952 revisions were identified and it was determined that the number one cause of failure was </span><span>aseptic loosening (23.19%)</span><span>, followed by instability (22.43%) and infection (22.13%).</span></div></li><li><div><span>Further analysis of applicable revisions investigated BMI and age at the failure rates.</span></div></li></ul><span>The rate of re-revision in obese patients was markedly higher </span><span>(p < 0.01) compared to non-obese patients and individuals receiving a revision THA under the age of 55 are at a higher risk of re-revision (p < 0.01).</span>”