Catastrophic Wear & PE Sterilization
So what companies make PE by direct compression molding?
Unicompartmental Knee Replacement
Question (SAE10HK.98) states that increased ROM is a distinct advantage of using a uni, but your didactic materials do not list this as an advantage. I would suggest adding that to the list if it is true. Thanks.
TKA Other Complications
This question comes up with the MOC 2016 course in the TKA complications section. Should be associated with the proper hip section.
TKA Sagittal Plane Balancing
This didactic section on sagital balancing is the best I have ever seen. Thanks so much for an excellent presentation! I have now got it down.
A 65-year-old healthy patient fell 18 years after a total hip arthroplasty and sustained the fracture shown in Figure A. What is the most appropriate treatment?
Percutaneous locked plating
Open reduction internal fixation with a cable plate and allograft strut
Revision to a long, porous coated femoral stem with biplanar allograft struts
Revision to a cemented revision femoral stem that bypasses the fracture site by 5 cm
Three months of non-weight bearing
Maddening that the answer does not mention allograft revision stem or tumor prosthesis but only states "long" porous coated stem sounding like this is a solution to a B2 Fx. Answer should be more specific to not cause confusion.
Treatment options for Hip osteonecrosis
58 yo female with no hx of etoh or steroid use. No trauma PMH hypercholesterolemia , anxiety and depression. quit smoking one year ago,Six months of hip pain getting worseHF 50 IR 5-10moderate limp without assistive device
Prosthetic Joint Infection
"triple scan can differentiate infection from fracture or bone remodeling"...................could somebody explain the text from the above topic please. What's a Triple Scan please.
What is the most common complication after revision of a total hip polyethylene liner in a patient with well-fixed femoral and acetabular shell components?
failure of the femoral component
failure of the fixation between the liner and the acetabular shell
fracture of the polyethylene
may i ask about the cause of increase dislocation complication ?
A posterior cruciate retaining total knee arthroplasty is contraindicated in all of the following patients EXCEPT?
52-year-old female with severe rheumatoid arthritis of the knee
73-year-old male with post-traumatic arthritis of the knee and prior patellectomy
67-year-old male with degenerative arthritis and 10 degree valgus deformity of the knee
55-year-old male with post-traumatic arthritis of the knee 20 years after bicruciate ligament ruptures
63-year-old female with a chronic history of steroid treatment of systemic lupus erythematosus and an arthritic knee
Why is patellectomy a contraindication to PCL retention in TKR please?
J Bone Joint Surg Am. 2009 Apr;91(4):773-82.
Why report linear wear? In the 30-year life of an implant, these numbers amount to a less than 1.5mm difference in total linear wear, an amount that I am certain makes no difference to the stability of the hip. Of course, there are ramifications for number of wear particles generated and resulting osteolysis, but then it seems that volumetric wear would be the more closely related number.
Video describing biofilm formation
Very good video
A 45-year-old with a history of sickle cell anemia reports hip pain for the past 6 months. A radiograph of the affected hip is shown in Figure A. Which of the following interventions has been shown to have the best outcomes in this patient population?
Uncemented metal on polyethylene total hip arthroplasty
Cemented metal on polyethylene total hip arthroplasty
The evidence used to justify the answer to this question is poor quality at best. One of the citations mentioned below references a paper looking at the outcomes in just 6 patients. Joint Registry data, while crude, suggests that in all age groups cemented implants out perform uncemented THR's. And yet these implants which are often more expensive are favoured over cement by many surgeons.I do not think the evidence supports the answer.
Infected NonUnion Tibia
Orthopaedic Principles-SICOT Lecture organised by Dr Hitesh Gopalan
J Bone Joint Surg Am. 2016 Oct 05;98(19):1638-1645.
The Accuracy of Imaging Techniques in the Assessment of Periprosthetic Hip Infection: A Systematic Review and Meta-Analysis.Verberne SJ, Raijmakers PG, Temmerman OPJ Bone Joint Surg Am. 2016 Oct 5. pii: 98/19/1638. doi: 10.2106/JBJS.15.00898. 98. (19). :1638-1645PMID: 27707850 (Link to Abstract)
THA Implant Fixation
Thank you for the great topic review. About Dorr classification: Ratio: inner canal diameter at midportion of lesser trochanter divided by diameter 10 cm distal, orinner canal diameter 10 cm distal to lesser trochanter divided by inner canal diameter at midportion of lesser trochanter?
A 67 year-old woman sustained an ACL tear while playing basketball when she was 35 years-old. She has noted progressive leg deformity and episodes of giving way, and now has pain preventing activity. Non-operative management has failed to provide relief. Treatment should consist of?
Opening wedge high tibial osteotomy with autograft
Closing wedge proximal tibial osteotomy
Medial interpositional arthroplasty
Medial unicompartmental knee arthroplasty
Total knee arthroplasty
Dr. Khurana - there are quite a few more variables that would be needed to determine if someone around 40 would benefit from an osteotomy, such as overall limb alignment, and presence of other ligamentous injuries around the knee. We purposefully chose to avoid these concepts for this question to minimize controversy and confusion.
Clin Orthop Relat Res. 2016 Feb;474(2):374-82.
A 69-year-old female 16 years status post total knee arthroplasty complains of knee pain. A radiograph is provided in Figure A. Which of the following is true regarding the pathogenesis of the bony abnormality seen in the distal femur?
It is related to the toughness of the polyethylene liner
It is more likely to occur with highly cross-linked polyethylene compared to conventional polyethylene
It is caused by macrophage activation by polyethylene particles
It is most frequently caused by infection
It occurs more frequently in patients taking immunosuppressive medications.
Dr. Anonymous - backside wear is when the polyethylene wears underneath it, at the junction of the baseplate and polyethylene in this instance.Backside Wear Is Not Dependent on the Acetabular Socket Design in Crosslinked Polyethylene Liners.Bali K, McCalden RW, Naudie DD, MacDonald SJ, Teeter MGClin Orthop Relat Res. 2016 Feb. doi: 10.1007/s11999-015-4471-y. pii: 10.1007/s11999-015-4471-y. 474. (2). :374-82PMID: 26201422 (Link to Abstract)
Internal rotation of the femoral component in primary total knee arthroplasty may lead to which of the following?
A net lateral patellar tilt and increased lateral subluxation
A decreased Q angle
A loose medial compartment and tight lateral compartment
Balanced medial and lateral flexion gaps
"taking 3 degrees external rotation off the posterior condyles was least consistent especially in knees in valgus" Is this due to hypoplastic lateral condyle?