The osteoarthritic knee and hip 2016

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COMPANY CONFIDENTIAL © COPYRIGHT 2016-2017 ConforMIS, Inc. 2

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COMPANY CONFIDENTIAL© COPYRIGHT 2016-2017 ConforMIS, Inc. 3

KNEE ANATOMYIMAGINGOA PATHOLOGYSURGICAL TREATMENTSPOST SURGICAL FIT ASSESMENT

HIP ANATOMYIMAGINGOA PATHOLOGYSURGICAL TREATMENTS

Knee Anatomy


Osseous Structures Femur-

Longest, largest, strongest skeletal bone

Cylindrical shaft made up of cortical bone and fat filled medullary

Condyles defined by trochlea anteriorly and intercondylar notch posteriorly

• Image from:http://en.wikipedia.org/wiki/Femur

http://en.wikipedia.org/wiki/Femur

Knee Anatomy


Osseous StructuresPatella-

Flat triangular sesamoid bone marking the anterior most portion of the knee joint

Thick superior border (base) and pointed inferior border (apex)

Cancellous bone enveloped by the quadriceps tendon

Image from: http://www.fpnotebook.com/_media/orthoLegPatellaAntGrayBB255.gif

http://www.fpnotebook.com/_media/orthoLegPatellaAntGrayBB255.gif

http://www.fpnotebook.com/_media/orthoLegPatellaAntGrayBB255.gif

Knee Anatomy


Osseous Structures Tibia-

Large superior portion, head, divided into two distinct portions, the medial and lateral condyles, separated by the tibial spine

Flat superior surface is called the plateau

Articulates with the femoral condyles Tibial tuberosity found on the anterior

portion serves as an articulation point for the patellar ligament

Fibula- Most slender of the long bones Articulates anteriorly and laterally with

the lateral tibial condyle

Images from:http://en.wikipedia.org/wiki/Tibiahttp://en.wikipedia.org/wiki/Knee

http://en.wikipedia.org/wiki/Tibia

http://en.wikipedia.org/wiki/Knee


Medial femoral condyle

Femoral shaft, distal end

Lateral femoral condyle

Patella

Medial tibial plateau

Head of fibula

Lateral tibial plateau

Knee Anatomy


Femoral shaft, distal end

Patella

Tibial plateau

Head of fibulaTibial Tuberosity

Femoral condyles

Knee Anatomy


Cartilage Dense connective tissue

Made up of chondrocytes which produce the extracellular matrix of water, collagen, and proteoglycan

Collagen is mostly type II, provides strength and structure No blood supply, nourishment is supplied by synovial fluid

Thickness Normally between 2 and 5mm’s Thickness can be correlated with highest peak pressure areas. The thickest cartilage in the

body is found in the patellofemoral joint Four distinct zones Superficial zone- highest collagen content which is aligned parallel to the articular surface,

lowest concentration of proteoglycan, 10% to 20% of the overall thickness Transitional zone- 40% to 60% of the overall thickness, collagen organization is random,

composed almost exclusively of proteoglycans Radial zone- distributes load and resists compression with parallel oriented highly organized

collagen fibers, and lowest water content Calcified cartilage zone- contains the tidemark which signals the transition between calcified

and uncalcified cartilage

Knee Anatomy


Articular Cartilage

Knee Anatomy


Joint Support External Support

Fibrous Capsule Encloses the joint, consists of

synovial membrane, thin connective tissue which secretes synovial fluid. This thick, high viscosity fluid helps lubricate the knee and reduce friction.

Extracapsular Ligaments Anterior - Patella ligament Lateral – Lateral collateral ligament Medial – Medial collateral ligament Posterior- Oblique popliteal ligament

and arcuate ligamentImage from:http://papruddenmor.blogspot.com/2011_05_01_archive.html

Knee Anatomy

http://papruddenmor.blogspot.com/2011_05_01_archive.html


Joint Support Internal Support

Anterior cruciate ligament (ACL) – provides rotation for the joint and prevents displacement anteriorly

Posterior cruciate ligament (PCL)- prevents posterior draw

Image from:

http://www.ehealthmd.com/yms_images/anterior_cruciate_375.jpg

Knee Anatomy




Menisci (from Greek meniskos, “crescent”) Medial and Lateral Fibrocartilaginous concave semicircles Articulates with the tibial plateaus Provides gliding surface for knee movement and absorbs tension

Knee Anatomy


Muscular SupportExtensorsQuadriceps femoris muscle group

Rectus femorisVastus lateralis,Vastus medialusVastus intermediusFlexorsHamstring muscle group SemitendinosusSemimembranosusBiceps femorisAssisting musclesGracilisSartoriusPopliteus

Vastus medialusQuadriceps tendon

Cancellous bone

Vastus lateralis

Biceps femorisSemimembranosus

Cortical bone

Sartorius

Knee Anatomy

Knee Anatomy


Lateral collateral ligament

Anterior cruciate ligament

Medial compartment

Lateral compartment

Lateral femoral condyle

Medial femoral condyle

Anterior cruciate ligament

Head of the fibula

Tibial plateau

Knee Anatomy


Patellofemoral compartmentQuadriceps tendon

Patellar tendon

Tibial spine

Posterior cruciate ligament

Cartilage bone interface

Articular cartilage

Lateral meniscus

Knee Imaging


Knee anatomy and pathology is generally demonstrated using

Routine radiographs, CR/DRCT with or without arthrogram contrastMR with or without arthrogram contrast

Knee Imaging


CRAPLateralTangential (sunrise)Full Leg – used for alignment measurement

DemonstratesCartilage loss/Joint space narrowingOsteophytes/bone spursSubchondral cystsSclerosisBone marrow edemaTraumatic injuries

Knee Imaging


UnacceptableAcceptable

AP - Position central ray at right angles to the joint space with no rotation. The resulting image should demonstrate the epicondyles in profile and the intercondylar eminence of the tibia centered within the intercondylar fossa of the femur

Knee Imaging


Acceptable Unacceptable

Lateral -Position central ray at right angles to the joint space with no rotation of the knee. The resulting image should demonstrate the posterior aspects of the femoral condyles superimposed.

Knee Imaging


CTDemonstrates:

Joint space narrowingSubchondral cysts Sclerosis Osteophyte formations

CT ArthrogramThe use of diluted contrast in joint delineates articular cartilage and ligaments

MRIDemonstrates

Grade of articular cartilage damageLigaments integrityMeniscal tears

*Knee MR protocols vary from site to site and can be dependent on the system

used to acquire the images*


Knee Pathology Pathology commonly associated with patients considering a

knee arthroplasty Osteoarthritis (OA) – defined as chronic inflammation characterized by

degeneration of the joints causing pain, stiffness, and swelling. OA is sometimes referred to as degenerative joint disease (DJD). Radiographically OA can be identified by the presence of osteophytes, bone edema, sclerosis, joint space narrowing and cyst formations.

Osteochondritis Defects (or Dissecans) (OCD) is characterized by cracks that occur in the articular cartilage and the underlying subchondral bone as a result of decreased blood flow. Avascular necrosis (AVN) or bone death as a result of the loss of blood flow leaves the articular cartilage vulnerable. Fragmentation of cartilage and bone, and subsequently loose bodies occur within the joint space, causing pain and additional damage. Radiographically loose bodies (bone fragments) can be seen. MR images demonstrate and stage OCD lesions in the cartilage.


Osteoarthritis (OA)Morbidity

Affects as many as 26.9 million AmericansOne of the most common causes of disability due to limitations in joint movement. By age 40 almost 90% of the American population will have some form of OA in their weight-bearing joints OA results in 632,000 joint replacements each year300,000 TKR surgeries annually in the US for end-stage arthritis of the knee joint.Causes ObesityGeneticsTraumaMetabolic disordersSymptomsPain SwellingLoss of mobility


OsteoarthritisJoint space narrowing

AP Lateral

Osteophyte formation

Tangential View (aka sunrise or merchant view)


OsteoarthritisJoint space narrowing

Note- Because the image was acquired bilaterally neither knee is demonstrated in a true AP position since the central beam was focused between the knees.

Weight bearing AP knees


Osteoarthritis

Image from:http://www.washingtonknee.com/knee-treatments/knee-osteoarthritis/

http://www.washingtonknee.com/knee-treatments/knee-osteoarthritis/




ICRS Hyaline Cartilage Lesion Classification System

Grade 1- Superficial lesions, cracks, and indentationsGrade 2 - Fraying, lesions extending down to <50% of cartilage depthGrade 3 - Partial loss of cartilage thickness, cartilage defects extending down to >50% of cartilage depth as well as down to calcified layerGrade 4 - Complete loss of cartilage thickness, bone only


Grade 4 articular cartilage loss- exposed subchondral bone, complete loss of cartilage

Grade 3 articular cartilage loss - >50% Grade 3 articular

cartilage loss - > 50%


Cartilage LossMR images


Grade 3 articular cartilage loss - >50%

Grade 3 articular cartilage loss - > 50%



Cartilage LossCT Arthrogram images

Subchondral CystMR images





Subchondral cystSubchondral cyst

Subchondral cyst

Subchondral cyst

Subchondral CystCT Images





Subchondral cystSubchondral cyst


SclerosisCR Images

Sclerotic changes – increased bone density

Sclerotic changes – increased bone density

Bone Marrow EdemaMR Image


Bone marrow edema


Results From interrupted blood flow to the area Injury to the cartilage and underlying bone

Osteochondritis Defect (OCD)


Osteochondritis Defect (OCD)

Stage Appearance on MRI & Stability of lesion Stage 1- Articular Cartilage Damage only Stage 2 - Cartilage injury with underlying fracture

a. Surrounding bony edema b. Without edema

Stage 3 - Detached but non-displaced fragment Stage 4 - Detached and displaced fragment


Stage II OCD

Stage II OCD

OCDMR images


Stage II OCDStage II OCD

Stage III OCDStage IV OCD

OCDMR images

Surgical Treatments - Knee


Surgeons-Seek the least invasive methodEncourage bone preservation

Less bleeding and post surgical painShorter recovery timesStill have bone to work with for potential revisions; Prosthesis failure rate requiring revision is ~1 percent per year



Arthroscopy – via a scope inserted through a small incision the surgeon views the joint capsule and can perform small repairs including removal of damaged cartilage and any loose bodies.

Hemi-Arthroplasty –

Uni-compartmental Arthroplasty – this procedure replaces only the damaged area of a single joint compartment with a prosthetic device.

Duo-compartmental Arthroplasty – this procedure replaces only the damaged area of the patella femoral joint and either the medial or the lateral compartment with a prosthetic device.

Osteotomy – a high tibial osteotomy involves removal of a wedge shaped piece of bone that results in realignment allowing the patients weight to be distributed away from the damage compartment.

Total Knee Arthroplasty – involves replacing all joint surfaces


“The success of primary TKR in most patients is stronglysupported by more than 20 years of followup data. Thereappears to be rapid and substantial improvement in thepatient's pain, functional status, and overall health-relatedquality of life in about 90 percent of patients; about 85 percentof patients are satisfied with the results of surgery.”

-NIH Consensus Statement on Total Knee Replacement




ConforMIS iUni® is a Uni-Compartmental Device

ConforMIS iTotal® is a Total Knee Device

ConforMIS iDuo® is a Bi-Compartmental Device

ConforMIS CT Order Form



ConforMIS CT ProtocolPatient IdentificationDICOM data reflects patient’s legal name with supporting documentation.

Patient PositionThe patient’s foot is perpendicular to the table.Toes up, use positioning aids if available.Device in the opposite knee? Bend that knee prior to acquiring any images to avoid scatter (see image). If available use an artifact reduction technique.No pillows or sponges under the knee or ankle of interest.Immobilization is essential, remind the patient to hold as still as possible.Remove foreign objects from field.


ConforMIS CT ProtocolExam Acquisition and Scan Review (also see side two)Bilateral Imaging is acceptable. Please reconstruct each leg independently.Review all images before the patient leaves the scan table. Anatomy cut-off? Reconstruct to include all anatomy. Motion or positional changes detected? All anatomic areas must be reacquired in their entirety.

Exam Archive and Transfer— Send all images to ConforMIS ASAPRetain a permanent copy of the study. Retain the raw data for as long as possible.Send ALL acquired data including the scout, images and dose page.Send via ConforMIS secure web, cloud sharing networks, direct connection or overnight priority shipping.


Protocol BuildWe recommend building a ConforMIS protocol in your CT scanner(s) with all of the appropriate rangesTable increment should not exceed slice thicknessKV/MaS Settings should be set at your standard setting for each of the anatomic ranges to be scanned. ConforMIS suggests employing dose reduction techniques whenever possible. All scans should be acquired in the helical/spiral mode, rotation speed not less than 1sec, pitch as close to 1:1 as possible, using the body filterFrom the full leg scout the hip, knee and ankle images may be acquired in a single scan acquisition (alternatively these anatomic areas can be acquired in separate series) Provide reconstructed series in the coronal and sagittal planes of the kneeSend all images that are acquired including the scout and dose page if available*

ConforMIS CT Protocol


Examples of Unacceptable Motion for ConforMIS Protocol CT Scans



Multiple areas of excessive motion



Motion is difficult to see on coronal reconstruction image. It is essential to review all series to detect motion.



The “wavy” appearance evident on these images indicates a problem with table motion. It can also happen when the gantry tilt is not at zero, although it may read zero. These issues need to be addressed before scanning ConforMIS protocol studies


Post Surgical Radiographic AssessmentRoutine CR images are acquired as part of a clinical

assessment of patients post knee arthroplasty to evaluate for common post operative complications that can cause pain and the need for revision surgeries.

Assess for fit – overhang or underhang of either component can lead to post–op pain

Alignment – one of the goals of PKR or TKR is to restore mechanical alignment

Loosening – Failure of PKR and TKR can be associated with component loosening

Osteolysis – bone reabsorption can occur in the area of the prosthetic

Wear – can occur in some of the components of the prosthetic


Post Surgical Radiographic AssessmentProper positioning is critical- unless directed to do so

by your radiologists or the orthopedic surgeon avoid bilateral images. The central beam should be directed at the knee joint

Weight bearing full leg –assess for alignment and leg length

AP and Lateral – assess for component position and fit

Tangential (aka sunrise or merchant view) – demonstrates the PF joint


Post Surgical Radiographic AssessmentAPAcceptable positioning Poor positioning


Post Surgical Radiographic AssessmentLateral

Acceptable positioning Poor positioning


Post Surgical Radiographic AssessmentSunrise or Merchant View

Acceptable positioning Poor positioning

Hip Anatomy


• Image and information from: http://www.healthpages.org/anatomy-function/hip-structure-function-common-problems/

Osseous StructuresHip

Ball (femoral head) and socket joint (acetabulum) joining the pelvis and femur

Acetabulum – composed of the innominate bone which includes the ilium, pubis, and ishium forming the socket into which the femoral head fits

Ilium

Ischium

pubis

http://www.healthpages.org/anatomy-function/hip-structure-function-common-problems/


Hip Anatomy


Osseous Structures

Image from:http://www.wikiradiography.net/page/Hip+Radiographic+Anatomy

http://www.wikiradiography.net/page/Hip+Radiographic+Anatomy



Hip Anatomy


• Image and information from: https://www.studyblue.com/notes/note/n/practical-2-structure-set-2/deck/8022588

• http://www.healthpages.org/anatomy-function/hip-structure-function-common-problems/

CartilageLabrum- The labrum is a

fibrocartilaginous structure that outlines the acetabular socket, usually triangular in shape

https://www.studyblue.com/notes/note/n/practical-2-structure-set-2/deck/8022588






Hip Anatomy


• Image and information from: http://mywwwzone.heckyeahllc.netdna-cdn.com/wp-content/uploads/2010/07/liofemoral-ligament.png

• http://www.healthpages.org/anatomy-function/hip-structure-function-common-problems/

LigamentsIliofemoral ligament -

strongest ligament in the body

Ischiofemoral ligamentsPubofemoral

These ligaments surround the hip joint providing stability

http://mywwwzone.heckyeahllc.netdna-cdn.com/wp-content/uploads/2010/07/liofemoral-ligament.png



Hip Anatomy


Hip motion is performed when several muscles act simultaneously. Several muscles are responsible for each directional motion. Some play a primary role in carrying out the motion and others function in a secondary role.

Hip Anatomy


Muscles of the Hip – allow for movement, most contribute to more than one type of movementFour Main Groups

Gluteal group - gluteus maximus, gluteus medius, gluteus minimus, and tensor fasciae latae.

Adductor group - adductor brevis, adductor longus, adductor magnus, pectineus, and gracilis

Iliopsoas group - iliacus and psoas major Lateral rotator group - externus and internus obturators, the

piriformis, the superior and inferior gemelli, and the quadratus femoris.***The rectus femoris and satorius contribute to hip motion but are generally considered as primarily knee muscles***

Hip Anatomy


• Image from: https://en.wikipedia.org/wiki/Muscles_of_the_hip

Hip Anatomy


Hip MovementFlexion - BendingExtensions - StraighteningAbduction – Moving the leg outward away from the bodyAdduction - Moving the leg outward away from the bodyMedial rotationLateral rotationCircumduction

Hip Anatomy


Flexion -Iliopsoas group -

iliacus and psoas major

Rectus femorisSatoriusTensor fascia lataePectineusAdductors longus

and brevisGracilis

Extension -Gluteus MaximusSemitendinosusBiceps FemorisSemimembranosus

Hip Anatomy


Adduction -Adductor brevisAdductor magnusAdductor longusAdductor minumusPectineusGracilisObturator externus

Abduction –Gluteus MediusGluteus MinimusTensor Fascia Latae

Hip Anatomy


Medial Rotation -Gluteus mediusGluteus minimusTensor fascia lataeAdductor brevis and

longusAdductor magnus

Lateral Rotation -Superior gemellusInferior gemellusObturator externusObturator internusQuadratus femorisPiriformis

Diagnostic Imaging


Hip anatomy and pathology is generally demonstrated using

Routine radiographs, CR/DRCT with or without arthrogram contrastMR with or without arthrogram contrast

Diagnostic Imaging


CR – Protocol variable by site but generally

AP Full pelvis - usually for the initial evaluationAffected hip only – subsequent evaluations

Lateral

DemonstratesJoint narrowingSclerosisOsteophytesBone cysts

Diagnostic Imaging


AP – Full Pelvis - Position the central ray at the mid point between syphysis pubis and ASIS. Internally rotate the patients foot 15o to 20o. Ensure there is no rotation.

Image from: https://www.dreamstime.com/photos-images/medical-xray-spine-pelvis.html

Diagnostic Imaging


AP – Unilateral - Position the central ray perpendicular to the femoral neck in question, at the mid point between syphysis pubis and ASIS over head of femur. Internally rotate the patients foot 15o to 20o. Ensure there is no rotation.

Image from : https://www.google.com/search?q=Hip+Radiograph&biw=1920&bih=897&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjR56vUi7fOAhUCSBQKHW1jDXIQ_AUIBigB#imgrc=VwiKQMXwndKEaM%3A

Diagnostic Imaging


AP oblique– Demonstrates the lateral aspects of the femoral head and trochanters. Patients hips and knees are flexed 90o with the feet up, soles facing or touching if possible, and the knees abducted 45o (frog leg). The CR should be placed between the ASIS and the pubic symphysis angled cephalad 10-15o. For unilateral imaging center on the affected acetabulum.

Information and image from: http://cdn.auntminnie.com/user/documents/content_documents/X-Ray_Patient_Positioning_Manual_080402.pdf

Diagnostic Imaging


CTDemonstrates

Joint space narrowingSubchondral cysts Sclerosis Osteophyte formationsReconstructions

Axial Sagittal Coronal images

CT ArthrogramThe use of diluted contrast in joint delineates articular cartilage and ligaments and some soft tissue structures

MR Demonstrates

Grade articular cartilage damageLigaments integrityMeniscal tears

*Hip MR protocols vary from site to site and can be dependent on the system used to acquire the

images*


Osteoarthritis (OA)


Osteoarthritis

Image from: http://www.parkclinic.com.au/home/conditions-treatment/hip/hip-osteoarthritis/


Grading Hip Osteoarthritis (OA)Radiographic Assessment

Grade 0 - NormalGrade 1 – Possible joint space narrowing and small osteophytes Grade 2 – Joint space narrowing, small osteophytes, sclerosis in acetabulumGrade 3 – Marked joint space narrowing, small osteophytes, sclerosis and cysts, with deformity of the femoral head and acetabulumGrade 4 – Extreme joint space narrowing, bone on bone, large osteophytes and severe deformities


Osteoarthritis CT Images Sclerosis

Osteophyte

Cysts

Joint space narrowing


Osteoarthritis CT Images

Sclerosis

Osteophyte

Cysts

Joint space narrowing


Osteoarthritis CT Images

Femoral head deformityJoint space narrowing

Osteophyte

Cysts

Sclerosis


Surgical Treatment of Hip OAPatients requiring hip arthroplasty

have moderate to severe arthritis in the hip, including osteoarthritis, rheumatoid arthritis or post-traumatic arthritis, that causes pain and/or interferes with daily living


Surgeons-Seek the least invasive methodEncourage bone preservation

Less bleeding and post surgical painShorter recovery timesStill have bone to work with for potential

revisions; Approximately 15% of hip arthroplasties annually in the US are revisions

Surgical Treatment of Hip OA


Arthroscopy – via a scope inserted through a small incision the surgeon views the joint capsule and can perform small repairs including removal of damaged cartilage and any loose bodies.

Osteotomy – Acetabular bone cuts are made to realign the hip to a more natural position

Varus Rotational Osteotomy (VRO) – Corrects femoral neck valgus anatomy (too straight)

Pelvic Osteotomy – Addresses acetabular deformities

Total Hip Arthroplasty – involves the removal of the femoral head and damaged surface of the acetabulum. The replacement implant consists of a metal or ceramic ball (replaces femoral head) on a femoral stem , a metal socket (replaces the acetabulum) and a liner between the ball and socket to provide a gliding surface.

Surgical Treatment of Hip OA


Post Surgical Radiographic Assessment CR images – AP, Lateral, Frog lateral and or cross table lateral are

acquired as part of a clinical assessment of patients post knee arthroplasty to evaluate for common post operative complications that can cause pain and the need for revision surgeries.

AP and Lateral – Must include full femoral stem and cement. Assess for component loosening, stem failure and infection

Frog lateral – Evaluate the proximal portion of the femoral component

Cross table lateral – Evaluate the position of the acetabular component and the integrity of the surrounding osseous structures

Weight bearing or push pull views – Demonstrates implant loosening or component wear

Full leg – Determine leg length differences

The osteoarthritic knee and hip 2016

Healthcare

Transcript of The osteoarthritic knee and hip 2016