Arthroplasty - RC Q's Flashcards
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>
A<div>Garcia RM (CORR 2008) Isolated all-poly patellar revision for metal-backed patella failure<br></br></div>
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>
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>
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>
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>
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>
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>
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>
“<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>”
<div>RC 2012 - 6 anatomical releases for balancing a varus knee</div>
<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>
RC 2016 - List 4 soft tissue releases for a valgus knee in TKA
<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>
<div>RC 2014, 2011 - List 3 technique to determine rotation of the femoral component in TKA.</div>
“<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>”
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>
“B.<div><br></br></div><div><img></img><br></br></div>”
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>
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>
RC 2014 - List 3 soft tissue releases to improve your flexion gap in performing a TKA
<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>
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>
“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>”
RC 2012 - 6 types of failure of a TKA requiring a revision
<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>
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>
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>
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>
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>
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>
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>
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>
D.
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>
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>
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>
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>
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>
B. dont be dumb
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>
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>
<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>
“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>”
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
<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>
<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>
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>
RC 2014 - List three ways to prevent PF maltracking in TKA
<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>
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>
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>
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>
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>
RC 2017 - What are 5 complications associated with valgus producing HTO, excluding bleeding and infection:
<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>
RC 2012 - 4 contraindications to HTO
<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>
RC 2016 - List 4 advantages of doing a medial opening wedge HTO over a lateral closing wedge.
<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>
<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>
“<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>”
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>
“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>”
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>
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>
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>
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>
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>
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>
RC 2014, 2011 - Picture of a BHR with a femoral neck fracture. Name 4 risk factors for this complication
<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>
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>
<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>
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>
“C.<div><br></br></div><div><img></img><br></br></div>”
<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>
“B.<div><br></br></div><div><img></img><br></br></div><div><img></img><br></br></div>”
<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>
C.