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MUSCULOSKELETAL

TYPES OF JOINTS:

synovial (diarthrosis or diarthodial):

appendicular skeleton

facet joints of spine

atlantoaxial

lower 2/3 of SI joint

uncovertebral joints

cartilagenous joints (amphiarthosis):

synchondrosis

pubic symphysis

intervertebral discs

fibrous joint:

interosseus membranes

tib-fib sydesmosis

subdural

CLASSIFICATION OF SOME ARTHRIDITES (see the figures below):

SEROPOSITIVE:

adult RA:

primarily affects synovial joints

F>M

can have seronegative RA

early in the course of dz, RF may be positive in the joint spaces before being positive in the serum

Rheumatoid arthritis:

RF (IgG) combines with antigen (IgG or IgM) to form immune complexes in the joint which activate the complement system attracting PMN's into the joint space resulting in diffuse multicompartment symmetric narrowing associated with marginal erosions, periarticular osteoporosis, and periarticular STS. It involves the large joints as well as small ones. In the knee, all compartments are involved. Involvement of the hip leads to axial or less commonly medial involvement. Get acetabulae protrusio in advanced cases. Get central or peripheral articular erosions. Resorpn of the ends of the clavicles. synovial cysts, and pseudocysts in close proximity to the joint. Also get joint effusion.

Small joint involvement-wrist, MCP, PIP of hands and feet. DIP's of hand are spared. Get STS (periarticular) and joint effusion which is the earliest symptom. Also edema, and tenosynovitis. Joint deformities are Swan neck, Boutonniere, and Hitch Hiker thumb. In advanced stages, get subluxation, dislocation of the fingers, ankylosis particularly in mid carpal locations, (more common in sero negative RA). T and L spine are only rarely affected in RA. The C spine is involved in 50% (odontoid, atlantoaxial, apophyseal joints). Transverse ligament laxity is the main problem here. Can also get SL ligament destruction.

Rheumatoid nodulosis:

Very high RF. Nodules on the extensor surfaces. M>F. No joint involvement

JCA:

this is a group of at least 3 chronic inflammatory synovial diseases that affect children. F>M:

Still's: fever, LAN, salmon colored skin rash, sometimes hepatosplenomegaly, fatigue, anorexia, wt loss, most have chronic or recurrent arthralgias

Polyarticular JCA: inflammation of 4 or more joints c associated findings of anorexia, wt loss, fatigue, adenopathy,. Growth retardation is common. Hypoplasia of the mandible and early closure of the growth plates causes short metacarpals. There is overgrowth of the epiphyses of the knees, shoulders, and hips. If positive RF, there is a worse prognosis.

Pauciarticular JCA: <4 joints in the first 6 months. Involvement of the SI joints is not a feature of JCA. JCA shows many of teh features of adult RA, but some have other features that are almost pathognomonic ie periosteal rxn along the shafts of proximal phalanges and metacarpals, joint ankylosis in wrist and interphalangeal articulations. Fusion of the apophyseall joints of the C spine is also characteristic. Because onset of JCA occurs before completion of skeletal maturation, involvement of growth of bones is common, and epiphyseal involvement leads to fusion of the growth plate with resultant retardation of bone growth. Accelerated growth may occur secondary to hyperemia. Epiphyseal enlargement of the knee may lead to overgrowth of the condyls of the knee.

SERONEGATIVE SPONDYLARTHROPATHIES:

AS principally affects the synovial joints of the spine as well as the SI joints. Peripheral joints such as the hips, shoulders, knees may be involved. M>F and younger age. Extraarticular features include iritis, pulm fibrosis, heart conduction defects, aortic regurge, cord compression, and amyloidosis. Pts may get low grade fever, wt loss, anorexia. 95% of pts are HLA B27 positive

One of the earliest radiographic features is squaring of anterior border of the lower thoracic and lumbar VB's. As the dz progresses, syndesmophytes form which bridge the VB's. They have a delicate appearance which distinguishes them from degenerative spine dz. Paravertebral ossifications are common. When apophyseal joints and VB's fuse late in the dz, the radiographic hallmark is bamboo spine. The SI joints are also affected. In the peripheral joints, inflammatory changes may distinguish them from those in RA. In the foot, get characteristic  erosion at the tendon insertion-os calcis. Involvement of the ischial tuberosities and iliac crests with new bone formation causes whiskering.

Reiter: M>F. Clinically it is an infectious dz characterized by arthritis, conjuctivitis, and urethritis. Also, characteristically get a mucocutaneous rash. Like AS, eye involvement is common (conjuctivitis, iritis, uveitis, episcleritis). 60% of pts are HLA B27 positive. Unlike AS, reiters can affect SI joints unilaterally. There are 2 types of reiters, sporadic (more common in t he US associated with gonococcal urethritis, M>F) and epidemic (more common in Europe) associated with shiglla dysentry and yersinia. In reiters, get assymmetric, peripheral arthritis. It has a predilection for lower limb joints, most commonly the foot. MTP and heel. SI joint involvtcan be symmetric or assymetric. In the T and L spine, get course syndesmphytes characteristically bridging the VB's.

Psoriatic: there are 5 subgroups:

type1: nail and terminal tuft of distal and occasionally proximal IP joints.

type 2: opera glass hand deformity or arthritis mutilans due to extensive destruction of the phalanges, and MCP joints with pencil in cup deformity. These pts also have sacroileitis.

type3: symmetric polyarthritis causing ankylosis of the PIP and DIP joints. Type 3 is frequently indestinuishable from RA.

type 4: oligoarthritis. Unlike type 3, joint involvment is assymmetric and includes the PIP and DIP as well as the MCP joints. It is this subtype that most commonly has "sausage digits"

Psoriasis involves mainly DIP of hands and feet but other sites ie PIP as well as hips, knees, ankles, shoulders, and spine may be found. There are few radiographic hallmarks to make the correct dx. The phalanges of the hand and foot may show fluffy new bone formation, which if periarticular is referred to as "mouse ears". In the advanced stage, can get "pencil in cup" deformity. In the heel, the late stage changes are broad based osteophytes and periostitis. PA of the spine has a high incidence of sacroileitis which can be unilateral or bilateral. As in Reiters, can cause syndesmophytes and paraspinal ossification.

Enteropathic: it is associated with UC, CD, whipples (intesinal lipodystrophy). Most pts are HLA B27 positive. The spine, SI, and peripheral joints are affected in all three types. In the spine, there is squaring of VB's, formation of syndesmophytes bilatrally, and a radiograph looking identical to that from AS. The activity of the peripheral arthritis follows that of the bowel disease

Erosive Osteoarthritis: it affects typically middle aged women. It combines the clinical features of RA and OA. Can be recognizes by involvement of the PIP and the DIP, and a characteristic "gull wing" pattern of articular erosion. Spontaneous fusion of the IP joints may occur. It is limited the hands

MISCELLANEOUS:

SLE: adolescent, M>F, B>W. these pts have malaise, weakness, anorexia, wt loss, positive ANA, rash

the hands, hips, ankles, shoulder are affected. Hands are predominant site of involvement. The key feature is flexible joint contractures particularly at the MCP and PIP of the fingures and the IP of the thumb. These are due to loss of ligament and capsular support

Schleroderma: F>M, skin changes, edema, thickening. There are ST Ca++, acroosteolysis. Most pts develop CREST syndrome. 30 to 40% are RF and ANA positive. There is atrophy of the ST's of the tips of the fingers, resorption of the distal phalanges, subcutaneous and periarticular Ca++, and destructive changes of small articulations. Usually the IP joints.

Gout: M>F, great toe. Also goes for large joints such as knee, and elbow. There is articular erosion with preserved joint space and overhanging edges. They lack osteoporosis. There is tophi and periarticular swelling.

CPPD: M=F:

variable joints: chondrocalcinosis of articular cartilage and menisci. Calcification of tendons, joints, ligaments, capsule.

femoropatellar joint: joint space narrowing, subchondral sclerosis, osteophytosis

the classic joints affected are the wrists, elbows, shoulders, ankles, with djd changes and chondrocalcinosis

hemophilia: M=F, large joints (hips, knees, shoulder), elbows and ankles. There is joint effusion, osteoporosis, symmetrical joint space narrowing, articular erosions, widened intercondylar notch, squared patella, it is very similar to the changes seen in JRA. In terms of frequency of joint involvement: knee>ankle>elbow>wrist>hip and shoulder. Hemophiliac pseudotumor most commonly occurs in the pelvis

hemochromatosis: M>F, hands, 2nd and 3rd MCP with beak like osteophytes and chondrocalcinosis

HPT: hands, multiple bones, skull, spine. There are destructive changes in the IP joints with subperiosteal resorption. Brown tumors. Salt and pepper appearance and rugger jersey spine

CAUSES OF ENTHESITIS:

AS, enteropathy, arthritis, PA, reiters, DISH, acromegaly. To distinguish DISH from AS, look at the SI joints. They are usually not affected by DISH

OA:

in OA, medial side of knee is affected which causes a varus deformity. The lateral aspect of the patellofemoral joint is also affected. In the wrist, involvement of the trapezio-scaphoid and the first CMC joints are the primary sites

CAUSES OF A HIGH T1: fat, flow, gado enhancement, extracellular methemoglobin, proteinaceous fluid, milk of Ca++, melanoma

AVASCULAR NECROSIS:

Sinding-Larsen-Johansson disease is osteochondrosis of the inferior pole of the patella, age 10-14 yrs. Sever's disease is a normal variant associated with weight-bearing that results in sclerosis and fragmentation of the secondary calcaneal ossification center. Kohlers disease is avascular necrosis of the tarsal navicular, usually boys 3-10 yrs

COMPLICATIONS OF TIBIAL PLATEAU FX:

lateral tibial plateau fx is the most common (85%)

according to the Schatzker classification, there are 6 types 1-6

type 3 is a pure compressonn fx and also the most common (35%)

type 5 is bicondylar

overall, types 1-3 are the most common

medial plateau fx's are associated with more violent injury

the complications are:

peroneal n injury (due to lateral compartment being more commonly injured)

OA

no anterior compartment sydrome as there is no anterior compartment located here

popliteal rupture and ligament injury

SLAC WRIST:

occurs spontaneously or after trauma, similar pattern to CPPD, get associated SL widening

PERILUNATE DISLOCATION:

this is the most common association with scaphoid waist fx

ULNAR CARPAL IMPACTION SYDROME:

it is TFCC tear and dissassociation of the LT ligament

PATELLAR DISLOCATION:

it is associated with patellar rim fx

LEGGE CALVE PERTHES:

it is bilateral in only 10%. It is much more common in boys

FX DISLOCATION:

Colles is not a fx dislocation whereas Barton is

OSTEOID OSTEIOMA:

shows pooling of contrast in the nidus

IS FIRST RIB FX ASSOCIATED WITH A HORNER SYNDROME:

the answer is no

HYPOPLASTIC TERMINAL TUFTS:

get hypoplastic terminal tufts and not acroosteolysis in association with pyknodystocis

LIGAMENTS CONTRIBUTING TOWARDS PELVIC STABILITY:

sacrospinous, sacrotuberous, sacroiliac ligaments all contribute toward pelvic stability 

SYNOVIAL CYSTS:

these are a will known manifestation of RA. They are common in the popliteal region

PARALYSIS:

there is an increased incidence of osteomyelitis

WHICH NERVE GOES THROUGH THE TARSAL TUNNEL:

the posterior tibial nerve!

WHICH OSSIFY IN MULTIPLE CENTERS:

trochlear and capitellum

LEGGE CALVE PERTHS:

the pain is rapid in onset 

ONE THING THAT CHARACTERIZES TB:

late preservation of the disc in spinal infections

SPONTANEOUS TENDON RUPTURE AND HOLES IN THE CARPAL BONES?

this is one complication of renal failure

APPEARANCE OF SCAPHOID ON THE LATERAL VIEW IN DISI:

it appears nearly lateral

SSD DACTLYLITIS:

occurs in children 6 mo to 2 years. It is most common in the hands and feet

ASSOCIATIONS WITH QUADRATUS TENDON RUPTURE:

RA, SLE, local steroid injection

LIGAMENTS IN CHILDREN:

they are stronger than the growth plate and therefore more likely to see growth plate injury than a tear in the ligament

SOME FEATURES OF PYKNODYSOSTOCIS:

dystrophic nails, yellowed teeth, beaked nose, wormian bones, non segmental C1 and C2, non pneumatized parnasal sinuses,tapered terminal tufts

SIEZURES:

you can see bilateral posterior shoulder dislocation

HILL SACH:

it is posterolateral and is best seen on internal rotation

BONE AGE AND OBESITY:

obesity can cause advanced bone age

OSSIFICATION OF THE ANNULUS FIBROSIS:

patients with AS have ossification of the annulus fibrosis which may be confused with ossification of the anterior longitudinal ligament. Ca++ of the posterior longitudinal lig is seen in DISH

CHANCE FX:

they are more commonly associated wtth seatbelt injury, but they can also occur with a fall from a height

CYSTIC ROBUST RA:

seen in younger athletic people. Osteoporosis is not a feature

OSA VS EWINGS:

OSA can met to bone more frequently than Ewings

ANTERIOR CLAVICLE DISLOCATION:

more common than posterior dislocation. Posterior dislocation of the L sternoclavic joint can injure the L BCV

RSD:

it is usually bilateral with involvement of one side more than the other

ACROMEGALY AND DISC CALCIFICATIONS:

acromegaly causes disc space Ca++ while HPT does not

SYNOVIAL CYSTS AND JRA?

rare in jra but common in ra

POST MENOPAUSAL OSTEOPOROSIS:

see elevated urinary Ca++ but normal blood Ca++

EPIPHYSEAL CUPPING:

trauma, rickets, scurvy, vit A toxicity

RUPTURED PT:

it is the most common cause of acute foot pain in women>50

PAGETS MARKERS:

urine hydroxyproline is elevated in pagets and so are blood alk phos levels. Note that bone resorption forms hydroxyproline and bone formation forms alk phos

GUYONS CANAL:

is bordered by the pisiform medially and the hook of the hamate laterally and contains the ulnar artery and nerve

CARPAL TUNNEL CONTENTS:

FCR (in  a separate compartment)

FDP, FDS, FPL, median nerve

MAGIC ANGLE:

is is most pronounced with short TE sequences

FOOT ANKLE ANATOMY:

inferior to the sustentaculum tali is the FHL

the most common injured tendon in the ankle is the TP, which is the one that inserts onto the navicular bone

think of tom, dick, and very nervous harry and you come up with tp, fdl, artery, vein, nerve, and fhl

in the foot, TDH passes beneath flexor retinaculum on its way through the tarsal canal, joined by the PT artery and PT nerve. Since the FHL passes under the sustentaculum tali, it can get entrapped between a sustentaculum tali fragment and medial calcaneal cortex following a compression fx of the calcaneous. The peroneal tendon can get entrapped between fragments of the lateral cortex.

BIT ON SINUS TARSI:

it is a cone shaped sinus which is larger medially and contains fat and neurovascular structures, and 5 ligaments including the ligament of the tarsal canal. Inversion injury causes sinus tarsi syndrome with lateral foot pain and loss of the fat signal. The 5 ligaments are medial, intermediate, lateral, and cervical ligament of the the tarsal canal

CONTENTS OF THE EXTENSOR RETINACULUM OF THE FOOT:

TA ---> EHL ---> EDL --->pertertius

(medial)                                    (lateral)

TALAR BLOOD SUPPLY:

most is carried in the interosseus ligament. The anterior and middle facets are in the subtalar joint, while the posterior is in the posteriior subtalar joint. Posterior is the largest and most important of the 3. Middle facet is part of the sustentaculum tali

FOOT PAIN IN ADOLESCENTS:

the most comomon cause is tarsal coalition

RHABDOMYOSARCOMA:

1/3 arise in striated m. The remaining 2/3 is in sites where striated m is not found

FAILED BACK:

3 causes of pain after back surgery: 1 failed back. 2 segmental spine instability, 3 discogenic pain from mechanical overload on a disc

ISAROV PROCEDURE:

0.5 mm/day, uses membranous ossification to increase bone lengh

TENDON SHEATHS:

long head of biceps and FHL communicate with joint space so fluid in the sheath can be normal. The peroneus longus t does not communicate with the joint space. The achilles has no tendon sheath. With tendon injury, you get increased T2 signal in the tendon from both partial tear and tenosynovitis. FHL and achilles are injured in ballet dancers. FHL uses sustentaculum tali as a pulley (see figure). In foot, although rare, the talonavicular joint is a target of CPPD

SESAMOIDS:

these are in the FHB tendon, not the FHL

Hallux valgus:

results form poor fitting footware. The angle between should be <20 degrees. In severe disease it is >35 degrees

HAMMER VS CLAW TOE:

FRACTURE CLASSIFICATION:

maxilla: lefort

AC joint: rockwoods

Proximal humerus: Neer

Epiphyseal: Salter Harris

Acetabular column: Letornel

Fem Neck: Garden

Proximal tibial: Muller

Patellar: Larsen

Ankle: Weber

ANTERIOR AND POSTERIOR SHOULDER DISLOCATION:

anterior: in shoulder, axillary a, brachial plexus, axillary and musculocutaneous branches lie anteroinferior to the glenoid so with first time anterior dislocation, the axillary n is the most likely to be injured

posterior: rotator cuff and neurovascular injury is less  common. Posterior cortical rim of glenoid and lesser tuberosity are fxd

ROCKWOOD CLASSIFICATION OF AC SEPARATION:

1: NL, 2: AC separation, 3: AC and CC separation, 4: total disruption

INNERVATION OF THE HAND:

dorsal: 2 1/2 to 2 1/2

volar 1 1/2 to 3 1/2 ulnar to radial nerve

CAUSES OF CARPAL TUNNEL SYNDROME:

PRAGMATIC or pregnancy, ra, gout, mass, amyloid, trauma, idiopathic, collagen vascular

HOLT ORAM:

it consists of a fingerized thumb and hypoplastic or absent radius, CHD, and an arched palette

PSEUDO AND PSEUDOPSEUDOHYPOPARATHYROIDISM:

the 4th and 5th MC are smaller than normal

pseudo are short, obese, mentally challenged, have skeletal resistance to PTH, hypocalcemia, and normal PTH

the pseudopseudo have all labs normal. The features are otherwise the same as pseudo above

BUNKBED FX:

it is a salter 1 or 2 of the base of the first MT which is the pediatric equivalent of the lisfranc fx

MR OF RHEUMATOID NODULES:

show increased SI on T2 while hyperlipidemia nodules show increased SI on T1

JOINT INVOLVMENT IN CPPD AND HEMOCHROMATOSIS:

both show involvment of the 2nd and 3rd MCP

PES ANSERINUS:

think SGT or sartorius, graculus, and semitendonosis

CAUSES OF METACARPAL SHORTENING:

May occur with  Turner's syndrome, Klinefelter's syndrome, trisomy 13 and 18, pseudohypoparathyroidism, pseudopseudohypoparathyroidism, trauma, basal cell nevus syndrome, melorheostosis, hereditary multiple exostoses, and ectodermal dsyplasia and also idiopathic

DWARFISM:

rhizomelia: short femur, humerus

mesomelia: short radius, ulna, tibia, fibula

acromelia: hands and feet affected

micromelia: entire limb affected

more on dwarfism quoted from radiologyweb.com:

Achondroplasia produces skull anomalies including brachycephaly and a hypoplastic skull base, vertebral anomalies including posterior scalloping, scoliosis, laminar thickening, rounded anterior beaking of the lumbar vertebral bodies, and widened intervertebral foramina, yet lumbar spinal stenosis from ventrodorsal and interpediculate space narrowing. Achondroplasia is also associated with squared flattened iliac bones in the shape of a tombstone, also termed "champagne glass," as well as horizontal acetabula, brachydactyly, and metaphyseal flaring. Ovoid vertebral bodies with central anterior tongue at lower thoracic / upper lumbar vertebral bodies is a finding in Morquio's syndrome, as are hypertelorism, pectus carinatum, failure of fusion of sternal segments, hypoplasia or absence of odontoid, platyspondyly, widened intervertebral disk spaces, and elongated pelvic inlet and flared iliac wings termed "goblet" or "wineglass" shaped pelvis. H-shaped vertebral bodies are characteristic of sickle cell anemia. Congenital vertebral body fusions are found in Klippel-Feil syndrome. Ankylosing spondylitis gives osteitis of the anterior corners of the vertebral bodies and ossification of the annulus fibrosus.

Trident hand, which is associated with achondroplasia, is characterized by fingers of nearly equal length. Cleido-cranial dysostosis is a syndrome noted for midline defects, including large head, decreased ossification of the skull, wormian bones, widened fontanelles and sutures with delayed closure, hypoplastic paranasal sinuses, hypoplastic clavicles, extra ribs, hemivertebrae, hypoplastic iliac bones, shortened radius, elongated second metacarpals, hypoplastic distal phalanges, pointed terminal tufts, coned epiphyses, and coxa vara. Ulna-minus variant has been associated with Keinbock's disease (avascular necrosis) of the lunate. In the vast majority of patients, the radial aspect of the lunate articular surface is even with the radial articular surface. An ulnar-plus deformity can result in tears of the triangular fibrocartilage and ulnar impingement syndrome. Holt-Oram syndrome is characterized by absence or hypoplasia of the thumb, 1st metacarpal, carpal bones, and radius. Nail-patella syndrome, also known as Fong disease, is characterized by hypoplastic nails of the 1st and second digits, abnormal iris pigmentation, renal dysfunction, bilateral posterior iliac horns (pathognomonic), hypoplasia of patella and radial head, and scoliosis.

FUSION ACROSS THE IP JOINTS:

this can occur across the IP joints with psoriasis, reiters, erosive osteoarthritis, and ankylosing spondylitis. With RA, bones will fuse at the level of the tarsals and carpals; if there is more distant fusion than this, then it is not RA and may represent one of the overlap sydromes

DISI:

it is associated with widened SL distance and horizontal configuration of the scaphoid

OSSIFICATION:

one bone where both membranous and enchondral take place together is the clavical

ACL TEAR:

bone bruise involving the lateral femoral condyl is very specific for ACL tear. Buckled PCL or posteriorly dispaced lateral meniscus are less specific. It involves lateral contusion of the femoral condyl and posterolateral contusion of the tibial plateau in addition to medial meniscal tear etc

EFFECTS OF PARALYSIS:

cartilage atrophy, osteomyelitis, osteonecrosis, heterotopic ossification

SHIN SPLINTS:

they have nothing to do with stress fractures. On nuc med study with 99mTcMDP, there is increased uptake on the skeletal phase (not the vascular or blood pool phases) in the posteromedial tibial cortex in its mid to distal aspect

RSD:

all 3 phases of the 3 phase bone scan are increased in 60%. It is associated with MI in 6%

VIEWS FOR PELVIC FX:

40 to 50 degree outlet view for showing posterior displacement of the iliium and SI joint

oblique view (also called Judet) is  for the acetabulum. Note that the outlet view is best for seeing vertical diastasis of the SI joint

AXILLARY NERVE DAMAGE:

occurs most commonly with anterior shoulder dislocation and can result in atrophy of the deltoid muscle. Note hat the radial nerve lies in the bicipital groove

ELBOW DISLOCATION:

bone fragment in relocatid elbow joint space is usually from coronoid in an adult and from medial epicondyl in a child

SEGOND FX:

bone chip just lateral to to lateral tibial plateau = ACL injury and lateral collateral ligament avulsion or tear

AMYLOID:

it can cause lytic lesions, osteoporosis or osteonecrosis, fx, and carpal tunnel sydrome

IVORY PHALANX:

can see it with psoriasis

TRANSIENT REGIONAL OSTEOPOROSIS:

It is analogous to sudeks. In the female the L hip is worse in the 3rd trimester. In men it involves both R and L hips about equally. M>F and 4-5th decade most common. It has a duration of about 9 months. It is also known as BM edema sydroma with lots of marrow edema. There is patchy osteoporosis of the hip. On MR, there is high T2 signal and a small effusion. Note that hip infection causes a large effusion

AL TOXICITY:

get spontaneous fx of the upper 2, 3, 4 ribs

PHEMISTERS TRIAD:

(refers classically to TB arthritis): juxtaarticular osteoporosis, gradual joint space narrowing, and periarticular erosions

EROSIVE OSTEOARTHRITIS VS RA:

EOA does not involve the MCP joints

MOST COMMON CAUSE OF LYTIC LESIONS ON BOTH SIDES OF A JOINT:

OA!

CAUSES OF DISC SPACE CALCIFICATION:

CPPD, acromegaly, hemochromatosis, HPT, neuropathic, ochronosis

WIDE SYMPHYSIS PUBIS:

cleidocranial dysostocis, bladder extrophy, ehlers danlos, HPT

SEGOND FX:

it is a fx of the margin of the anterolateral tibial condyl via avulsion fx of the insertion of lateral capsular ligament. The ddx is fx of Gerdy tubercle more posteriorly where the ITB attaches. It is associated with ACL tear (up to 100%), and MCL injury

POST MENOPAUSAL OSTEOPOROSIS:

horizontal trabeculae are more thinned than the verticle ones

PRINCIPLE EVERTER OF THE FOOT:

PT tendon. Patients with RA are more prone to rupture of the PT leading to painful flat foot

BEST VIEW FOR PELVIC DIASTASIS:

outlet

MR OF SPINAL DISCITIS:

bright disc and bright endplate on T2

CAUSES OF CUPPED EPIPHYSIS:

rickets, scurvy, trauma, XRT, infection, vit A, sickle cell, bone dysplasias

PARS DEFECT:

secondary to degenerative change is most common at L4,5 and secondary to pars defect is most common at L5,S1. The defect is located just above the level of the disc space which is just above the level of the NF

ROTATOR CUFF INJURY:

supraspinatus>infraspinatus>subscapularis>teres minor (SIST)

when tendons degenerate, the result is decreased echogenicity on US

PILLAR FX VS UNILATERAL LOCKED FACET:

flexion and rotation causes pillar fx

extension and rotation causes unilateral locked facet

MYOSITIS OSSIFICANS ASSOCIATION:

most closely with hip dislocation.

SUPRACONDLYAR FRACTURE:

in the normal, the anterior humeral line passes through the middle 1/3 of the capitellum

AVULSION FRACTURE:

ASIS is sartorius, AIIS is rectus femorus, pubic ramus is adductors and gracilus, lesser trochanter is iliopsoas

Anterior superior iliac spine - sartorius

Pubis - adductor longus

Ischium - hamstrings

FRACTURE CLASSIFICATIONS:

garden: femoral head

tile: acetabulim

weber: ankle

schatzker: tibial plateau

essex lopresti: calcaneus

CDH:

most commonly affects L hip (70%). Bilateral is 5%. In CDH, < 50% of the head is covered by the acetabulum. Note that the acetabular cartilage is more echogenic than the femoral head cartilage

TRANSIENT OSTEOPOROSIS OF THE HIP:

m>f and L>R (for female)

BERQUIST TRIAD: 

spine/pelvis fx

Diaphragmatic rupture

Rib fx

MOST COMMON CAUSE OF HPT:

Adenoma accounts for 80% of cases of hpt

PRIMARY HPT:

see brown tumors, chondrocalcinosis

SECONDARY HPT:

osteosclerosis, rugger jersey spine, soft tissue Ca++

HAND SCHULLER CHRISTIAN DISEASE:

Hans schuller Christian disease is triad of diabetes insipitus, multiple lytic bone lesions, and exopthalmos

SOME ARTHRIDITES:

Squared patella is a finding in hemophilia

Pseudoarthrosis is associated with ankylosing spondylitis

Protrusio acetabulae is associated with rheumatoid arthritis

Mouse ears are associated with psoriatic arthritis

HYPERPARATHYROIDISM:

In HPT, subperiosteal resorption occurs along the medial aspect of the proximal humerus and the tibia and along the radial aspect of the metacarpals  

TARSAL COALITION:

calcaneonavicular>talocalcaneal (middle facet)>talonavicular>calcaneocuboid. It is associated with peroneal flat foot in the 3rd decade. Talar beaking is more commonly seen in talocalcaneal with narrowing of the posterior subtalar joint. The etiology is congenital, acquired, infection, trauma, surgery

PERIOSTEAL VS PAROSTEAL OSTEOSARCOMA:

periosteal: cleavage plain, looks like juxtacortical chondrosarcoma, worse px than parosteal. Periosteal OSA shows a saucerized cortex in the diaphysis and an associated ST mass. The differential dx is parosteal OSA and Ewings (5% of Ewings look like periosteal OSA)

parosteal: looks like myositis ossificans and has a broad based attachment. The metaphyseal cortex is saucerized, and there is an associated ST mass

in terms of location, 85% of periosteal OSA are in the femur, usually the diaphysis. The mean age is 22 (9-74) while parosteal is in posterior distal femur. The mean age is 30

STRESS SHIELDING:

shielding of portion of bone or entire bone from mechanical stress due to internal fixation device resulting in demineralization and loss of intrinsic strength of the bone

STRESS RISER:

bone has some flexibility compared with the orthopedic hardware. The portion of the bone with the hardware becomes stiffened. On either side of the IM rod, the bone maintains its normal flexibility resulting in a transition zone that is a common site for fx called a stress riser

ADAMANTINOMA:

classic location is in the anterior 1/3 of the distal tibial diaphysis

OPLL:

20% of cases are found to have DISH. The C spine is most commonly affected site. It is not associated with AS

CAUSES OF NEURPATHIC JOINT:

syringomyelia, DM, leprosy, neurosyphilis, myelomeningocele, sp cord injury, congenital insensitivity to pain

PAGETS:

1-5% or <1 % incidence of sarcomatous degeneration. Ivory vertebra (densely white). Also picture frame vertebra (also called bone within bone)

LINES OF ACETABULUM:

1: anterior column (iliopectineal line)

2: posterior column (ilioischial line)

3: roof

4: anterior lip

5: posterior lip

6: teardrop (seeing it does not tell you whether the quadrilateral surface is intact or not)

SLAC:

this is scapholunate advanced collapse. It has an appearance also known as the stepladder configuration. It is most typial of CPPD. The radiocarpal joint is commonly affected in CPPD. Other things which help suggest CPPD are TFCC chondrocalcinosis, and or calcification of the SL ligament

LOOSENING OF PROSTHESIS:

normally <2mm band of lucency surrounding a prosthesis which may be fibrous tissue or Mach effect. > 2 mm indicates loosening

TELANGIECTATIC OSA:

it is highly lethal. Looks like ABC or SBC histologically

CLEAR CELL CHONDROSARCOMA:

proximal femur or humerus. It has affinity for end of bone like GCT. It is a low grade malignancy clinically.

INVOLUCRUM:

in osteomyelitis, involucrum is envelope of new bone . The dead cortical bone in the middle surrounded by the involucrum is called the sequestrum. Invulute=envelope ie surround

BRODIE ABSCESS:

In children. They are subacute and well defined. Involve the metaphysis, rarely the epiphysis

OSTEOFIBROUS DYSPLASIA:

formerly called ossifying fibroma. It differs from the classic FD in that the OD has bone spicules rimmed by osteoblasts. Lesion is usually in the anterior diaphyseal cortex of the tibia or fibula and have a rim of schlerosis.  Anterior bowing of the involved bone is sommon, Most occur by 10 years old

FIBROUS DYSPLASIA:

shepards crook deformity. Expansile lesion in distal fibula diaphysis. All polystotic dz have the tendency for one side of the body. With the polyostotic form, have polyendocrinopathy, sex precociousness, cushings, acromegaly, HPT, DM

EWINGS:

histol resembles PNET, prefers metadiaphysis (44%), mid diaph (33%), mataph (15%), and epip (2%). Long bones 60% and flat bones 40%

HODGKINS:

bimodial is peaking at 3rd to 5th decade. B symptoms are fever, night sweats, wt loss, superior LAN is the hallmark of HD. 10% initial involvement as lung involvement.

HPT:

In addition to subperiosteal resorption in the hand both the medial proximal tibia and medial humerus are also affected. Also seen in superior and inferior edges of ribs, and undersurface of distal clavicle

ABC:

some consider it to be an intraosseus or periosteal vascular malformation. It is thought to arise in response to trauma or a lesion. Underlying causes are GCT, chondroblastoma, FD, telangiectatic OSA. Sometimes, the ABC completely replaces the inciting tumor such that it can no longer be found. 75% of ABC are metaphyseal in long bones

H SHAPED VB:

SS anemia, gaucher, thalassemia

MORE ON OPLL:

it is seen in 50% of pts with DISH and 20% of pts with OPLL have DISH

MORE ON CPPD:

it likes the medial tibial femoral joint space and the lateral patellofemoral joint space

CAUSES OF ACROOSTEOLYSIS:

scleroderma, psoriasis, raynauds, thermal injury, hyperparathyroidism

LUNG FEATURES OF SARCOID:

honeycombing or cystic changes involving the UL predominantly

CAUSES OF IP FUSION:

psoriasis, AS, EOA, reiters, and not RA. Note that RA fuses at the level of the tarsals and carpals

SHOULDER:

anterior dislocation 96%. The shoulder is in external rotation, and abduction. May be associated with fx of the greater tuberosity. There is risk of brachial plexus injury

posterior can be traumatic or atraumatic. The traumatic is due to ECT, convulsions etc and 50% are unrecognised intitially. They have the "rim sign" and the trough sign which is a reverse hill Sachs lesion.Ie a compression fx of the anteromedial humeral head. There is an associated avulsion of the lesser tuberosity. The light bulb sign is present due to internal rotation

DISI AND VISI

1=scapholunate dislocation (looks normal with widened SL interspace). There is a 3 mm gap between the lunate and scaphoid also called the Terry Thomas sign. there may be a ring sign on the PA view secondary to rotatory subluxation of the scaphoid

2=capitolunate dislocation (---> perilunate dislocation). The capitate is dislocated dorsally. While the lunate maintains its articulation with the radius

3=triquetrolunate dislocation (--->midcarpal or transcaphoid dislocation). The triquetral ligaments are ruptured and there is dorsal dislocation of the capitate and carpus and volar dislocation of the lunate

4=dorsal radiocarpal dislocation (--->lunate dislocation). The lunate dislocates volarly while the capitate appears to be aligned with the radius

BIT MORE ON NEGATIVE ULNAR VARIANCE:

normally, there is a 80% to 20% ratio of distribution of forces on the radius and ulnar. Get 100% loading on the radius with negative ulnar variance. This results in malacia of the lunate. 80% of pts with Kienbochs have negative ulnar variance. However, 20% of the normal population also have negative ulnar variance, so it is not specific for it. It is counted as negative or postitive if it is > or < than 2 mm

HIV ARTHROPATHY:

looks like seronegative arthropathy with periostitis. There is LE predominance. Axial skeleton is spared. There is sacroileitis sometimes

TENNIS ELBOW:

It is lateral epicondylitis. With golfers, the flexor muscles of the forearm cause medial epicondylitis

CENTER EDGE ACETABULAR ANGLE IS ANGLE OF WYBERG:

it is normally> 20 degrees. In DDH, there are 3 types: Type 1 is dislocatable, unstable. Type 2 is partially dislocateable, subluxed. Type 3 shows flattening of the femoral head

TB OF THE JOINT:

the hip is the most commonly affected joint

MM:

70% male predominance. 98% are > 40 years old. Most pts are assymptomatic. Bence Jones proteinuria in 50%. Thirty four percent are plasma cell type. There are uniform skull lesions

AMYLOIDOSIS:

1ary: no pre existing cause. Heart muscle, lungs, synovium, perivascular tissue. It is associated with plasma cell myeloma as the 2 disorders have similar onset

2ary: type is most associated with MSK involvement. Occurs in late coarse of chronic dz. Eg long term HD, osteomyelitis, infections.

3ary: familial, associated wiht nephropathy, neuropathy, cardiomyopathy

4ary: localized form in tracheo esophageal tree

amyloidosis causes lytic lesions  in the femoral head and neck, shoulder, olecranon, wrists, bulky soft tissue masses. Also, in 8% of people, it causes carpal tunnel syndrome

OCHRONOSIS:

it causes decreased disc spaces height. The Ca++ are laminated. There are Ca++ inner fibers of the annulus. Ochronosis and acromegaly Ca++ is HADD. All other is CPPD

CHONDROBLASTOMA VS GCT:

chondro is dark on T1 and T2 while GCT is low or intermediate on T1 and bright on T2

MARROW DEVELOPMENT:

distal ----> proximal. for hematopoietic being replaced by fat

FIRST CMC INVOLVEMENT:

OA, gout, scleroderma, EOA, not reiters. It is classic for OA and EOA

LUPIS ARTHRITIS:

the arthritis is non erosive. The ball catcher view is the best

ENTHESOPATHIES:

AS, psoriasis, reiters, DISH. Shoulder is very infrequently affected by OA

SYNOVIAL OSTEOCHONDROMATOSIS:

when synovial chondromatosis ossifies, it is caused synovial osteochondromatosis. Common locations are hip, knee, shoulder

ODONAHUE UNHAPPY TRIAD:

medial collateral ligament tear, acl tear, medial meniscal injury

note that an ACL tear is associated with meniscal injury. Lateral meniscal injury > medial in 65%

note also that a PCL tear is most likely to be isolated

MORE MUSCULOTENDINOUS INSERTIONS:

ACL: lateral femoral condyl

PCL: medial femoral condyl

biceps femorus: styloid process of fibula

iliotibial band: gerdy tubercle on lateral tibia

still more anteriorly is capsular attachment which is the site of segond fx

ULNAR VARIANCE IN TFCC TEARS VS KIENBOCHS:

positive ulnar variance is associated with tfcc tears

negative ulnar variance is associated with kienbochs

POINT OF RUPTURE OF INFRAPATELLAR TENDON:

it breaks at the tibia first

CAUSE OF OSTEOMYELITIS IN PTS WITH SSD:

S. Aureus. This is also the  most frequent pathogen to cause diskitis

SOME FRACTURE DISLOCATIONS:

barton, galeazza, monteggia, bennett. Note that bennett is an intraarticular fx-dislocation of the base of the 1st MC while a rolando is a comminuted bennett

CAUSE OF OBLITERATED SINUSES:

obliterated paranasal sinuses are from extramedullary hematopoiesis seen in thalassemia. It is not usually seen in SSD

CAUSE OF BIG DIGITS:

NF, Maffucci, macrodystrophia lipomatosa, Klippel trenaunay (these can also have local gigantism)

ANKLE INJURY:

eversion injury causes a tranverse fx of the medial malleolus and a spiral or transverse fx of the fibular 

inversion injury causes a transverse fibula fx and an oblique fx medial malleolus

HADD:

most commonly affects the shoulder joint, usually monoarticular. Other name is milwaukee shoulder. It also affects the wrist, hand, foot, L spine. HADD causes calcific tendonitis. The supraspinatus tendon is the most frequent site. CPPD is commonly associated with HADD

CAUSES OF ST CA++:

trauma, burns, neuro injury, calcific tendonitis, CVD, HPT, gout, CPPD, infection, sarcoid

SPINE DIVISIONS:

for the purposes of injury, the spine is divided into 3 columns. Two of these have to be disrupted to get instability

LIPOSARCOMA:

there are 4 types. well differentiated, myxoid, round cell, pleomorphic. The round cell is the most common. Both liposarc and lipoma can occur in muscle. Lipoma is not a precursor lesion of liposarc. It is the second most common tumor after MFH. It is commonly affecting 40 to 60 y old. It affects the leg, glut, and the thigh (42%) which also happens to be the most common site of involvement. The abdominal wall (42%) is also commonly affected

CPPD:

wrists, hips, knees (particularly patellofemoral joint). Pseudogout is secondary to CPPD; chondrocalcinosis knee>symphysis>TFCC

SCFE:

12-14 yo M>F, B>W, if in girls, 20 to 25% bilateral. Slippage is posteriorly, medially and inferiorly

LCLC:

anteriorly is ITB, medially is LCL which is thickening of the lateral retinaculum and posteriorly is biceps femorus tendon. Also included is the popliteus tendon, and lateral head of  the gastrocnemius. It also includes the patellar retinaculum and the arcuate ligaments

VAN BUCHEM SYNDROME:

AR and presents at an earlier age than Worths which is AD. It is endosteal hyperostosis of the cortex of the tubular bones. They are not expanded. There is mandibular enlargement however and it also affects the skull, clavicle, ribs, long bone diaphyses and can lead to cranial nerve palsy. The spinous processes also appear thickened and sclerotic

CHANCE FX:

most common location is T12-L2

CAUSES OF EPIPHYSEAL OVERGROWTH:

hemophilia, JRA

HIP DISLOCATION:

femur in adduction with posterior hip dislocation and abduction with anterior hip dislocation. Posterior dislocations are the most common type

PNEMONIC FOR DENSE METAPHYSEAL LINES:

Heavy Cretins Sift Scurriously Through Rickety Systems which translates to:

Heavy metal, cretinism, syphilis, scurvy, rickets, sytemic illness

ROBUST RA:

it is a subtype of RA which is seronegative in 50%. Due to increased pressure in the joint, the joint fluid decompresses into the cortex. There is no periarticular osteoporosis

SOMETHING YOU MIGHT REMEMBER FOR 5 MIN:

Masabrauds sydrome: polyostotic FD and ST myxomas

OSTEOGENESIS IMPERFECTA:

type 1-2: blue schlera, types 3-4: normal schlera, types 1 and 4: dental abn, type 2: 10% death in utero

RHABDOMYOSARCOMA:

kids> adults

male > female

head and neck > GU tract

tumors of the vertebrae:

VB: gct, eg, hemangioma, mets, lymphoma, myeloma, sarcoma

Posterior elements (benign): abc, osteoblastoma, osteoid osteoma (AOO)

CHLOROMA:

another name is granulocytic sarcoma. It is a collection of leukemic cells commonly found in the skull, spine, ribs and sternum of leukemic kids

PNEMONIC FOR AVN OF THE HIP:

ASEPTIC G: i think the words are alcoholic, sickle cell dz, environmental, pancreatitis, trauma, idiopathic, collagen vascular dz, gaucher but dont quote me on it.  Note that HbSC is 5 x more likely to affect the femoral head than HbSS which is 3 x 

POPLITEAL ARTERY ENTRAPMENT SYDROME:

classically the popliteal artery is medially displaced. Symptoms are brought on by plantar flexion of the foot. It is seen more in atletes. M>F. Calf claudication after exercise. There is another disease known as adventitial cystic disease which results in smooth tapering of a segment of the popliteal artery. There is loss of the popliteal pulse with flexion of the knee. Most common in males in their third decade. Scimitar sign seen when cyst compresses vein with knee flexion

LANGERHANS CELL HISTIOCYTOSIS:

letterer-Siwe Disease: 1w to 2 y old, hemorrage, anemia, fever, FTT, hepatosplenomegaly, lymphadenopathy, bones affected in 50% with widespread lytic lesions (raindrop pattern), 70% mortality

HSC: triad of exopthalmos, diabetes insipitus, and lytic skull lesions. Affects 1-5 years old children. The lytic bone lesions cause "floating teeth". There are blebs in the lungs, which cause ptx in 25%. Nodular infiltrate may progress to fibrosis and end stage lung disease. The prognosis of HSC is one of spontaneous remissions and exacerbations

EG has a peak age of 5-10 y like HSC. There are lytic bones lesions which are monostotic in 50-75%. The skull  has a bevelled edge with the wider end of the bevel against the outer skull surface. These lytic lesions contain a button sequestrum. The spine shows vertebra plana and the lungs show upper lobe reticulonodular pattern which can progress to honeycomb lung. There are recurrent pneumathoces in 25% and the prognosis is excellent

PAGETS OF THE SKULL:

osteoporosis circumscripta which is the osteolytic phase commonly seen in the frontal bone. It has a cotton wool appearance with mixed lytic and sclerotic lesions. The inner and outer table are both involved and there is diploic widening. There can be basilar invagination with narrowing of the foramen magnum. This can cause cord compression. The neural foramina at the base of the skull may be narrowed leading to CN nerve symptoms such as hearing loss, facial palsy, blindness etc

in terms of degeneration of pagets:

osa>fibrosarcoma>chondrosarcoma; note that the rate of malignant degeneration of pagets is <1%

PAGETS INCIDENCE:

pelvis>femur>skull> tibia> vertebra> clavicle. See picture frame vertebra if it involves the spine

AVN STAGES:

1: normal

2: osteoporosis or osteosclerosis

3: subcortical fracture with the crescent sign

4: loss of the bone contour

EG THE SKULL:

skull is commonly involved (50%) with well defined lytic lesions.They may have a bevelled edge giving a hole in a hole appearance. This shows that the outer table is destroyed more than the inner table. The lesions may coalesce and form geographic skull. In the healing phase the lesions may develop sclerotic borders. You can see a floating tooth in the alveolar portion of the mandible

OSTEOBLASTIC METS:

prostate, breast, colon and hodgkins

OSTEOLYTIC:

thyroid, renal, and lung

EWING:

chordoma, chondrosarcoma, and osteogenic sarcoma are more likely to show calcifications as compared with Ewings

STABILITY OF CERVICAL SPINE FX:

flexion subluxation: s

bilteral facet dislocation: u

simple wedge fx: s

flexion teardrop fx: very u

clay shovelers fx: s

jefferson fx: u

burst fx: s

extension teardrop fx: stable in flexion, unstable in extension

hangman: u

POLYOSTOTIC FD:

cafe au lait spots are present in > 50%. Monostotic FD is more common than polyostotic

LEFORT FX:

1: transverse maxillary fx involving the alveolar ridge, lateral aperture of nose, and the inferior wall of the maxillary

2: involves the posterior alveolar ridge, medial orbital rim, and goes across nasal bridge

3: involves the nasofrontal suture, maxillofrontal suture, orbital wall, and zygoma (it is the only one of the 3 that involves the zygoma)

ANTERIOR TIBIAL COMPARTMENT SYDROME:

the most common cause of anterior compt sydrome is simple tibial fx

TRANSIENT OSTEOPOROSIS OF THE HIP:

M>F and pregnant female in the third trimester of preganancy more common than at other times. There is edema of both the femoral head and neck on T2

FOOT INSERTIONS:

PT: navicular, peroneus brevis: base of 5th MT, peroneus longus: base of 1st MT and 1st cuneiform, plantaris: calcaneus

MORE MUSCLE INSERTIONS:

hamstrings: ishial tuberosities, rectus femoris: AIIS, adductors: pubic symphisis and inferior pubic ramus, psoas major: lesser trochanter, sartorius: ASIS, brachialis: coronoid process of ulna, biceps: proximal radius, wrist flexors: medial  epicondyl, wrist extensors: lateral epicondyl

HEMOCHROMATOSIS AND CPDD:

both affect the 2nd and 3rd MCP

CONTENTS OF THE TARSAL SINUS:

contains interosseus ligament

CONTENTS OF THE TARSAL TUNNEL:

PT runs through it. the tunnel is located behind and below the medial malleolus

BEHCETS VS FELTY:

behcets: sacroileitis, occasional osteoporosis, STS, atlantoaxial subluxation

felty: RA, splenomegaly, leukoplakia

SCOLIOSIS (GREENSPAN):

idiopathic (70%): infantile (<4 yo) (M>F) has 2 variants; thoracic > lumbar L

resolving variant: curve not > than 30 degrees; spontaneously resolves

progressive variant: severe deformity with poor prognosis

juvenile idiopathic (4-9 y) (M=F)

adolesent (10 to skeletal maturity) (M > F); it is the most common type. It represents 85% of the cases; there is a thoraco or thoracolumbar curve to the R

congenital: this is 10% of cases. It is classified into 3 groups. failure of vertebral body formation (partial of complete), failure of vertebral segmentation (assymetric, unilateral, bilateral) (see figure)

then there are miscellaneous forms: neuromuscular, traumatic, infections, metabolic, and secondary to tumors

WHAT IS THE BIFURCATE LIGAMENT?

it goes from the superoanterior calcaneus to both the cuboid and navicular bones

5D OF NEUROPATHIC JOINT:

destruction, dislocation, disorganization, density, debris

USE OF THE JUDET VIEW:

for anterior and posterior columns of the pelvis for acetabular fx

BOEHLER'S ANGLE:

28 to 40 degrees

SPINAL COMPRESSION FX:

it usually involves the superior VB and endplate

CHILD ABUSE TYPE FXS:

metaphyseal corner fxs, outer end of clavicle, sternal fx, VB fx, posterior rib

MULTIPLE NOF:

associated with NF1

INCIDENCE OF NF1 VS NF2:

NF1: 90% and NF2: 10%

MOST COMMON BONE TUMORS IN THE FIRST DECADE:

lymphoma, and leukemia. NOT multiple myeloma

OSTEOBLASTOMA:

aggressive and non aggressive varieties. vert body (35%), and long bones (30%). The thoracic is the most common of the VB lesions. Diaphyseal involvement is 75% and metaphyseal involvement is 25%. Epiphyseal involvement is very unusual

CHONDROBLASTOMA:

<30 y old with pain and swelling, tender, epip and metap of long tubular bones. There is periostitis in 30%. It is the opposite (ie dark on T1 and T2) to osteoblastoma. As for GCT, osteoblastoma shows decreased T1 and increased T2. 15%-25% with  hemorrage can simulate ABC

CHONDROMYXOID FIBROMA:

least chance of malignancy. Ca++ is rare. They are well defined with sclerotic margins

OSTEOCHONDROMA:

>2 cm thickness of cartilage cap has increase chance of malignancy

CHORDOMA:

children sphenoccipital synchondrosis is most common location and in adults, sacrococcygeal is most common location

VERTEBRA PLANA:

EG: 70%

HSC: 10%

multiple myeloma; if in a child, for malignancy, dont think MM, but consider leukemia

SPONDYLOLISTHESISS:

most posterior aspects of the spinous processes demonstrate a step off above the level of the slip

PSEUDOSPONDYLOLISTHESIS:

the  most posterior aspect of the spinous processes demonstrate a step off below the level of the slip

ACROMEGALY:

there is a decreased bone density (osteoporosis) and increased heal pad thickness (>23mm in men)

MPS (MUCOPOLYSACCHARIDOSES); HUNTER VS HURLER:

all are AR. Hunter is X linked recesive. All have cloudy eyes except Hunter (needs clear eyes to hunt). All have coars features and are mentally challenged except morquio which have normal intelligence. Morq are killed by their C spine due to atlantoaxial subluxation

MARROW PATTERNS:

there are 4 types:

1: infanct (homogenous on MR)

2: childhood 11-15 (have high to intermediate diaphyseal marrow)

3: adolescent 16-20 (increased fat fraction iN the diaphysis) They have patchy metaph red marrow but the adult pattern is fully expressed

4: adult (> or equal to 21): adult pattern

By age 15 the clivus has homogenous high intensity marrow on FSE. On conventional SE, fat is dark

HERNIATION PITTS:

these occur in the femoral neck and are due to herniation of synovium into the femoral neck. They are assymptomatic

NEER CLASSIFICATION OF PROX HUM FX:

grade 1-4. the grade is equal to the number of fx fragments. If they are all none displaced, then is is counted as only one fragment. To be displaced, they have to be separated by > 1 cm About 80% of the fractures are non displaced

DDX OF RADIAL RAY DEFECT:

fanconi anemia, TAR, fetal thalidomide or valproate exposure, VATER, Holt oram, Blackfan Diamond, Cornelia de Lange, Tris 18

THE 3 STAGES OF ROTATOR CUFF INJURY:

1: edema and hemorrage

2: fibrosis and thickening

3: tear

and AC distance of <7mm suggests a rot cuff tear. So does fluid or contrast in the subacromial and/or subdeltoid bursa. Os Acromiale is also associated with rot cuff tear and impingement and should be mentioned

ACROMIAL SHAPES:

1: straight

2: curved or downsloping

3: hooked

2 and 3 are associated with impingement

SHOULDER STABILIZERS:

important is the rotator cuff capsule. Of the ligaments, the inferior glenohumeral lig is the most important of the anteroinferior stabilizers. If the middle glenohumeral ligament is hypertrophied, it suggests congenital absence of the superior labrum, and in this situation, is called a Buford complex

OSTEOPETROSIS:

can be fatal in infancy. There is generalized sclerosis due to a deficiency of carbonic anhydrase. This results in decreased osteoclast function and generalized sclerosis and cortical thickening resulting in obliteration of the bone marrow cavity. Eventually need a bone marrow transplant

RADIATION INDUCED BONE TUMORS:

OSA>MFH>fibrosarcoma>chondrosarcoma (10%)

STERNOCLAVICULAR DISLOCATION:

anterior > posterior. Posterior is associated with more serious (neurovascular) injury

IVDU "S JOINTS":

SI, SC, Spine

DDX OF ABC:

telangiectatic OSA, GCT, hemophiliac pseudotumor

OSTEITIS CONDENSANS:

F>M, mechanical stress resulting in proximal clavicle sclerosis. It does not involve the joint space. The ddx is OO, FD, mets, OSA

DOUBLE CRUCIATE SIGN:

due to a displaced inner meniscal fracture fragment from a bucket handle tear

PSEUDOMENISCAL TEAR:

popliteus, transverse geniculate ligament, lig of Humphry (anterior to PCL) and Wristberg (anterior to PCL)

SEGOND:

it is associated with a tear and avulsion of the anterior and lateral tibial capsule

HYPOPHOSPHATASIA:

this is the same as vit D resistant rickets

SYNOVIAL CYST:

continuous with the joint capsule. It comes from degeneration or trauma. Also from chronic joint effusion.

MENISCAL CYST:

commonly on the lateral side of the knee. It is associated with a meniscal tear. The fluid is viscous

GANGLION CYST:

mucin containing. Arises from the tendon sheath or joint capsule. It can also come from a bursa. In bone, it is called a subchondral cyst

OCD:

it is the sequela of transchondral injury. The etiol is trauma, ischemic necrosis, ossification anomalies, genetic. Also ligamentous laxity can predispose to it. 75% affect the posterolateral aspect of the medial femoral condyl. M>F and 15 to 20 is the most common age. Femoral OCD's are bilateral in 50%. Lesions that are <0.2 cm2 are stable and those >0.8 cm2 in area are unstable. You need MR with intraarticular contrast to determine whether or not the fx is stable

GRADING OF PATELLAR LESIONS:

chondromalacia patella is the most common cause of knee pain. It is called chondromalacia patella in young adults and is called OA in the elderly or older adults

grade 1: softening

grade 2: blistering

grade 3: fibrillation, ulceration, or fragmentation

grade 4: defects extending to subchondral bone

It affects the medial aspect of the patella more than the lateral aspect

the above grading is done with MR using T1 with fat sat. T2 is not used as cartilage is bright

TIBIAL PLATEAU FX:

minimally displaced is <4 mm. 55-75% lat plateau and 11-31% both. 10-23% affect the medial

with lateral 8-10mm is surgical

lateral 6-8 mm is good px with surgical or not

medial: all need surgery

50% of tib fib fx need operative treatment

with tib plat fx, popliteal damage is not likely. There is a 5% incidence of peroneal nerve injury. The MCL and medial meniscus are the most commonly injured structures associated with tibial plateaux fx

ACTINOMYCOSES:

jaw>thorax>abdomen

BONE INFARCT:

causes are fat emboli, alcohol, pancreatitis, steroids

complications are MFH, fibrosarcoma, OSA

LCH:

skull (50%) more commonly involved . The outer table is more involved than the inner table giving it a bevelled edge

MORE ON HYPOPARATHYROIDISM:

pseudo and pseudopseudohypoparathyroidism both show short 4th and 5th metacarpals

RADIAL RAY ABNORMALITIES:

osteochondrodysplasias

cornelia de lang

holt oram

TAR

VACTERAL

RICKETS:

widened physis, cupping, fraying, irregular distal metaphysis, generalized osteopenia, delayed bone age, rachitic rosary

PAINLESS ST MASSES:

most common cause of such multilobulated masses around the elbow, shoulder, knee is tumoral calcinosis from hyperparathyroidism, hypervitaminosis D, milk-alkali syndrome, renal dz etc. Most common in 2nd and third decade

SALTER CLASSIFICATION:

1 (6-8.5%): most common in the phalanges and the distal radius (includes apophyseal avulsion and scfe)

2 (73-75%): distal radius, distal tibia (corner sign) and fibula, phalanges

3 (6.5-8%): distal tibia, distal phalanx, rarely distal femur

4 (10-12%): lateral condyl of humerus, distal tibia

5 (<1%): distal femur, proximal tibia

IN CHILD:

supracondylar fx: 55%

lateral condylar fx: 20%

medial condylar fx: 5%

radius (salter 2,4): 10%

ulna linear fx through the proximal shaft: 10%

SOME USEFUL LINES:

McRae: this line passes from across the foramen magnum. The tip of the odontoid should lie below this line

Chamberlain (think ceiling): from tip of hard palette to opisthion (cephalad) aspect of it

McGregor: use as a substitute for Chamberlain if the opistion is not visible. This line is from the hard palatte to the most caudal aspect of the posterior aspect of the foramen magnum. The tip of the odontoid should be <5mm above the McGregor line

SHOULDER:

axillary neuropathy causes problems with adduction and IR

SLAP:

superior labral injury causes problems with IR

CORTICAL DESMOID:

this is an avulsive cortical irregularity of the posteriormedial aspect of medial femoral epicondyl along the medial ridge of the linea aspera at the attachment of the adductor magnus

INDIUM LABELED WBD  VISUALIZATION OF OSTEO IN ANTIBIOTIC TREATMENT:

probably no change in the false negative rate

MOST COMMONLY INJURED ANKLE LIGAMENT:

ATFL is the most commonly injured ligament. The most commonly injured tendon is the PT

FIBULA FX'S:

Potts: fx of the fibula above intact talofibular ligament

Duyputrens fx: fx of the fibula above ruptured TF ligament

Maissoneuvre: even higher up

PYOMYOSITIS:

common in young men with HIV, immunocomprimized. Most common organism is Staph Aureus. It prefers the thigh, LE

MR GRADING OF MENISCAL INJURY:

CAUSES OF SUBCHONDRAL CYSTS:

djd, cppd, synovial osteochondromatosis, pvns, gout, neuropathic joint, ra, avn

CAUSES OF CHONDROCALCINOSIS:

hyperparathyroidism, ochronosis, gout, wilsons, arthritis, pseudogout, hemochromatosis

PRIMARY BONE TUMORS:

osteogenic non malig: osteoma, osteoid osteoma, osteoblastoma

osteogenic malig: OSA

chondrogenic benign: enchondroma, osteochondroma, chondroblastoma, chondromyxoid

 fibroma

chondrongenic malig: chondrosarcoma

fibrous non malig: FD, NOF, OF, FCD, desmoplastic fibroma

fibrous malig: MFH

bone marrow: EG

bone marrow non malig: ewings, mm, lymphoma, leukemia, adamantinoma, chordoma, malig GCT

other: ABC (SBC), UBC, GCT, brown tumor, pseudotumor, hemangioma

malig other: hemangioendothelioma, angiosarcoma

VERTEBRAL ABNORMALITIES:

fish: SSD, thalassemia

squared: AS, psoriasis, reiter

ivory: mets, lymphoma, pagets, infection

WORMIAN BONES:

named after Dr. Olas Worm

associated with OI, pyknodysostosis, cleidocranial dysostosis, healed rickets, hypothyroidism

COMMON SKULL NEOPLASMS:

epidermoid, hemangioma, LCH

CALVARIAL LUCENCIES:

myeloma, mets, hemangiomas, pagets, neuroblastoma, histiocytocis

MOST COMMON MALIGNANCY IN THE ST'S OF THE FOOT:

synovial sarcoma

TILLAUX FX:

it is an avulsion fx of the lateral margin of the tibia. If instead you get avulsion of the medial aspect of the fibula with an intact ATF ligament, then this is called a Wagstaffe LeFort fx

TRIPLANE FX:

the part of the fx through the tibial metaphysis is in the coronal plane, and exits through the posterior aspect of the tibia. Tillaux is not a Salter 4 but a combination of a Tillaux (salter 3) and the coronal component (Salter 2)

APPROACH TO MR OF THE SHOULDER (H JANSEN):

BM

AC joint

bursas

cuff (ss, is, tm, sub)

biceps

labrum

cartilage

notches (suprascap, spinoglenoid)

APPROACH TO MR OF THE KNEE (H JANSEN):

effusion

BM

ACL

PCL