Musculoskeletal

Tennis leg

partial or complete tear of plantaris myotendon

Discoid meniscus

More than 14 mm medial to lateral meniscal width commonly involves lateral meniscus failure of resorption of central portion Watanabe classification Complete Incomplete Wrisberg type: no posterolateral meniscal attachment to tibia

Meniscofemoral ligament

From posterior horn of lateral meniscus to medial wall of intercondylar notch Humphrey: ligament passes anterior to posterior cruciate ligament Wrisberg: ligament posterior to posterior cruciate ligament

Chondral injury classification

grade 0: normal grade 1: softening grade 2: partial thickness defect, <50% cartilage depth grade 3: partial thickness defect, >50% cartilage depth grade 4: full thickness defect with or without underlying bone changes

Sinding Larson Johannson syndrome

chronic traction or avulsion of proximal patellar tendon at inferior pole of patella

Osgood Schlatter disease

repetitive traction/avulsion at patellar tendon insertion on tibial tubercle

Sever disease

fragmented sclerotic apophysis of posterior calcaneal process

Kager fat pad

Pre Achilles fat pad

Haglund deformity and triad/syndrome

Deformity: enlarged superior margin of posterior process of calcaneus Triad/syndrome

Check rein deformity

tethering of flexor hallucis longus tendon by flexor retinaculum

Master knot of Henry

place where flexor hallucis longus crosses flexor digitorum longus in foot

Weinstabi classification of achilles injury

Type I: inflammatory response Type II: degenerative changes Type III: partial tear Type IV: complete tear

Skimboarder toe

rupture of dorsal joint capsule due to hyperdorsiflexion

Sand toe

rupture of dorsal joint capsule due to plantar flexion

turf toe

rupture of plantar plate due to hyperdorsiflexion

Chaput Tillaux fracture

avulsion of anterior inferior tibiofibular ligament from lateral margin of anterior tibia

Volkman fracture

Earle fracture posterior inferior tibiofibular ligament avulsion from lateral aspect posterior malleolus

Freiberg infraction

2nd metatarsal head osteonecrosis or osteochondral fracture Mottled sclerosis and lucency flattening of head bone marrow edema Smillie classification Stage I: epiphyseal fissure surrounded by sclerosis Stage II: mild subchondral collapse Stage III: prominent medial and lateral projection of MT head Stage IV: MT head projection fracture, central area of collapse Stage V: extensive articular…

Stress response, fatigue and insufficiency fractures

Stress response: bone marrow edema, long segment periosteal reaction but no fracture line Fatigue fracture: abnormal stress on normal bone Insufficiency fracture: normal stress on weak bone

5th metatarsal fractures

Tuberosity avulsion fracture Jones: metadiaphyseal junction traumatic fracture Stress: similar to Jones, more distal

Lisfranc fracture dislocation types

Homolateral: all metatarsals displaced laterally Divergent: 1st metatarsal displaced medially with rest displaced laterally Partial: not all TMT joints involved Isolated: single TMT joint dislocation Longitudinal: medial displacement of first MT and TMT from rest of Lisfranc joint

Lisfranc ligament

Three components

Sangeorzan classification of navicular body fractures

Type I Coronal fracture, no dislocation Type II Dorsolateral or plantar medial fracture with medial forefoot displacement Type III Comminuted fracture with lateral forefoot displacement

Sanders classification of calcaneal fractures

Two categories Based on number of fracture lines Type I non displaced, no matter how many fracture lins Type II single displaced fracture line – 2 part Type III two displaced fracture lines – 3 part Type IV comminuted Based on position of main fracture line A: lateral 1/3 of joint B: middle 1/3 of…

Hawkins classification of talar neck fractures

Type 1 Non-displaced Type 2 Displaced with posterior subtalar joint disruption Type 3 Displaced with disruption of both ankle and posterior subtalar joints Type 4 Displaced with disruption of ankle, posterior subtalar and talonavicular joints

Osteochondral lesion of ankle

The two common sites posteromedial and anterolateral talar dome Focal injury of articular cartilage and underlying bone sclerotic fracture line concavity of subchondral bone

Weber classification of malleolar fractures

Type A fracture below level of tibial plafond Type B fracture at level of tibial plafond Type C fracture above level of tibial plafond

Os Vesalianum

accessory centre of styloid process base of 5th metatarsal

Os Peroneum

Peroneus longus sesamoid Near lateral margin cuboid ostitis in psoriatic or reactive arthritis, tendinopathy

Ossicles around the navicular bone

Os supranaviculare at dorsal proximal margin Accessory navicular type 1: sesamoid in tibialis posterior tendon type 2: os tibiale externum. at plantar margin of median eminence of navicular. tibialis posterior inserts on this os type 3: enlarged median eminence

Os trigonum

Posterior process of talus Anterior apex Tear drop shape

Sesamoid bone

Ossicle within a tendon Arises to provide a mechanical advantage

Talar axis

Longitudinal line through talus It is aligned with a longitudinal line through the first metatarsal When talar axis below 1st MT axis, pes planus When talar axis is above 1st MT axis, pes cavus

Ankle joint space

Evaluate joint in mortise view Look at medial, lateral and superior components Normal space: <4 mm Equivocal: 4-6 mm Abnormal: >6 mm, suggests ligament injury

Standard foot MRI protocol

Sagittal T1 and STIR Axial T1 and PD fs Coronal PD and T2 fs

Standard views ankle radiograph

AP Mortise Lateral

Lisfranc joint and ligament

Collective name for tarsometatarsal joints Lisfranc ligament maintains stability. Consists of 3 bands that extend from 1st cuneiform to medial base of 2nd metatarsal Injured in forcible plantar flexion of midfoot. Seen as lateral subluxation of 2nd TMT on weight bearing radiograph

Chopart joint

Components: talonavicular and calcaneocuboid joints Both are separate joint cavities but together called the Chopart joint Supination and pronation occurs here

Subtalar joint

3 facets: anterior, mid and posterior The anterior and mid facets form the anterior subtalar joint Posterior subtalar facet forms the posterior subtalar joint which is a separate joint cavity. It bears 50% of the weight and in 15% of population communicates with ankle joint. Inversion, eversion and gliding motion permitted in this joint Anterior…

Components of foot

Forefoot: metatarsals and phalanges Midfoot: all tarsal bones other than talus and calcaneum Hindfoot: talus and calcaneum

Lateral collateral ligament of ankle

Components: anterior and posterior talofibular ligament and calcaneofibular ligament Protects from inversion, anterior translation and rotation stress

Syndesmotic ligaments of ankle

Components include: anterior inferior and posterior inferior tibiofibular ligaments and interosseous ligament Anterior inferior tibiofibular ligament has an accessory band called the Basset ligament slightly inferior to it Posterior inferior tibiofibular ligament has another component inferiorly called the transverse (intermalleolar) ligament Injured in eversion or pronation stress or a rotational injury Keeps fibula in fibular…

Pilon fractures

Axial load injuries Articular surface of tibia is disrupted

Ideberg classification of intraarticular glenoid fractures

Kuhn classification of acromion fractures

Thompson classification of scapula fractures

Zdravkovic and Damholt classification of scapula fractures

Classification of acromioclavicular joint injury

Neer classification of distal clavicle fractures

Allman classification of clavicle fractures

Foreign body

Delayed onset muscle soreness (DOMS)

MR grading of muscle injury

Non accidental trauma / child abuse

Common sites of fracture

Rotator cuff anatomy

Skyline view radiography of knee

Simple bone cyst

Non ossifying fibroma

Shoulder radiography projections checklist

Shoulder survey Anteroposterior 15 degrees erect or supine Superoinferior (axial) Inferosuperior (axial) Anteroposterior outlet projection Lateral oblique outlet projection Shoulder joint trauma Anteroposterior erect Anteroposterior supine  Lateral oblique Y projection Recurrent dislocation  Anteroposterior (lateral humerus) Anteroposterior (oblique humerus) Anteroposterior (modified) – Stryker Inferosuperior  Calcified tendons  Anteroposterior  Anteroposterior with medial rotation of humerus Anteroposterior with lateral…

Typical lumbar vertebra

Osteochondroma

Limbus vertebra

Lumbosacral root syndrome

Root injury Dermatome pain Muscle supplied Movement weakness Reflex involved L1 Groin  Iliopsoas  Hip flexion  Cremaster  L2 Anterior aspect thigh Iliopsoas, sartorius, hip adductors Hip flexion, adduction Cremaster  L3 Medial aspect of knee Iliopsoas, sartorius, quadriceps, hip adductors Hip flexion, knee extension, hip adduction Patellar L4 Medial aspect of calf Tibialis anterior, quadriceps Foot inversion,…

Cervical root syndrome

Root injury Dermatome pain Muscle supplied Movement weakness Reflex involved C5 Lower lateral aspect upper arm Deltoid and biceps Shoulder abduction, elbow flexion Biceps C6 Lateral aspect of forearm Extensor carpi radialis longus and brevis Wrist extensors Brachioradialis  C7 Middle finger Triceps and flexor carpi radialis Extension of elbow, flexion of wrist Triceps  C8 Medial…

Intervertebral disc

Discs constitute 1/4 length of vertebral column Thickest in cervical and lumbar region, where movement is greatest Act as shock absorbers  Loses resilience with advancing age Consists of 2 parts: peripheral annulus fibrosus and central nucleus pulposus  Annulus fibrosus: fibrocartilage, collagen fibres arranged in concentric layers or sheets. Peripheral fibers strongly attached to anterior and…

Atlanto-axial joint

Consists of three synovial joints. One between odontoid process and anterior arch of atlas, other two between lateral masses of bones  Apical ligament: connects apex of odontoid process to anterior margin of foramen magnum  Alar ligaments: on each side of apical ligament, connect odontoid process to medial sides of occipital condyles Cruciate ligament: 2 parts…

Osteoid osteoma

5th edition WHO classification of pediatric bone tumors

Osteogenic tumors Subungual exostosis Bizarre parosteal osteochondromatous proliferation Osteoblastoma Osteoid osteoma Chondromesenchymal hamartoma of chest wall Osteosarcoma Chondrogenic tumors Chondroblastoma Osteochondroma Chondromyxoid fibroma Enchondroma and enchondromatosis Chondrosarcoma Mesenchymal chondrosarcoma Other tumors Vascular tumors of bone Aneurysmal bone cyst Giant cell tumor Non ossifying fibroma Notochordal tumors Simple bone cyst Adamantinoma Osteofibrous dysplasia Fibrous dysplasia

Garden classification of hip fractures

Stage 1  Undisplaced, incomplete, including impaction in valgus  Stage 2  Complete fracture, no displacement Stage 3  Complete fracture, varus angulation Stage 4  Completely displaced

AJCC staging of malignant bone tumors

Stage Grade  Size Metastasis IA Low < 8 cm None  IB Low  > 8 cm None  IIA High < 8 cm None  IIB High  > 8 cm None  III Any  Any  Skip metastasis IVA Any  Any  Pulmonary metastasis IVB Any Any  Non-pulmonary metastasis

Hip avascular necrosis

Idiopathic Trauma and vascular Fracture Radiotherapy Dysbaric osteonecrosis Arteritis Inflammatory Pancreatitis Connective tissue disease Rheumatoid arthritis Metabolic and endocrine Pregnancy Diabetes Cushing’s syndrome Gaucher’s disease Toxic  Steroids  Alcohol Immunosuppressives Hematological disorders Sickle cell anemia Polycythemia rubra vera Hemophilia 

Flexor digitorum profundus injuries

Pathological classification Type 1 tendon retracts to palm, blood supply disrupted, tendon sheath scar Type 2 tendon retracts to proximal interphalangeal joint, flexor digitorum profundus is caught at chiasm of flexor digitorum superficialis Type 3 flexor digitorum profundus avulsion plus large osseous fragment. Bony fragment lodged at distal edge of A4 pulley Zonal classification Zone…

Expansile benign bone tumors of hand

Giant cell tumor  Benign and aggressive High local recurrence 15-45 years Typical location – metacarpals Imaging  Metaepiphyseal osteolytic lesion Geographic bone destruction Internal ridges and smooth margins Sometimes cortical destruction Can be complicated by aneurysmal bone cyst Aneurysmal bone cyst Tumor-like with multiple blood-filled cavities Seen in younger population than GCT Metacarpals common site May…

Chondrosarcoma of hand

Malignant tumors of hand extremely rare Most common is chondrosarcoma due to malignant transformation of pre-existing enchondroma Enchondroma turning malignant most common in Ollier disease (multiple enchondromas) Quite often diagnosed as late as 10 years after onset. No specific clinical symptoms Rarely ever metastasize, so local amputation is done to avoid recurrence Imaging  Metacarpal or…

Bizzare paraosteal osteochondromatous proliferation

Earlier called Turret exostosis Affects proximal and middle phalanges of hand  Metatarsals, long bones (femur and tibia) may be involved 14-74 years of age Painless mass Imaging  Well-defined lobulated mass < 3 cm in size Pedicle or sessile bony attachment Underlying cortex intact No true continuity of ossification No mass or calcification in soft tissues…

Types of glomus tumors of the nail bed

Type Features Vascular contains numerous vascular lumens. Enhancement very high post Gadolinium with high T2 signal. Early enhancement in angiography with increase in delayed venous phase Cellular proliferation of epitheloid cells, less vascular lumens. Difficult to detect in scans. Gadolinium does not help much. 3D GRE imaging may show a peripheral capsule, or slight bone…

Sites of predilection in osteoarthritis of hand

Type Sites Osteoarthritis Proximal and distal interphalangeal joints Rheumatoid arthritis Metacarpophalangeal and proximal interphalangeal joints Crystal induced arthritis Second and third metacarpophalangeal joints

Grading of proximal interphalangeal joint instability

Grade 1 Distal avulsion of volar plate from base of middle phalanx.Hyperextension of PIP joint. (swan-neck deformity)Proximal avulsion of checkreins less common and can cause pseudoboutonniere deformity Grade 2 Volar plate injury extends to collateral ligaments.Dorsal subluxation produces more instability. Volar plate tilting with detachment of collateral ligament Grade 3 Fracture-dislocation of distal attachment of…

Sakakibara arthroscopic classification of medial plica

A cord-like elevation in synovial wall B shelf-like without covering anterior medial femoral condyle C large and shelf-like, covers anterior medial femoral condyle D central defect or fenestrated

Types of Morel-Lavallee lesion

I fluid-like serohematic effusion II subacute hematoma III chronic, organizing hematoma IV perifascial dissection, closed fatty tissue laceration V perifascial pseudonodular lesion VI infection with or without thick capsular septations and sinus tract

Jackson and Feagin grading of muscle contusion

Mild active or passive range of motion limited to less than 1/3 of normal. 6 days of disability. Moderate active motion limited to 1/3 to 2/3 of normal range due to muscle spasms. 56 days of disability Severe active motion limited to more than 2/3 of normal range of motion. More than 60 days of…

Grading of muscle strain

1 minimal disruption of musculotendinous unit (MTU). muscle spasm or cramp 2 partial tear with some intact MTU fibres. discomfort during sports or training, but resolves with rest 3A complete rupture of MTU 3B avulsion fracture at tendon origin or insertion

Arthroscopic/imaging classification of shoulder impingement

Type 1: rotator cuff degeneration or tendinosis without visible tears on either surfaceType 2: rotator cuff degeneration or tendinosis with partial-thickness tears of either articular or bursal surfacesType 3: complete-thickness rotator cuff tears of varying sizes, complexity, and functional compromise

Waldenstrom’s staging of Legg-Calve-Perthe disease

Initial stage increased head-socket distance, subchondral plate thinning, dense epiphysis Fragmentation stage subchondral fracture, inhomogeneous dense epiphysis which is porous, metaphyseal cysts Reparative stage normal bone in areas of resorption, removal of sclerotic bone. epiphysis is more homogeneous Growth stage re-ossification. normal femoral shape is approached Definitive stage final shape determined with joint congruency or…

Herring classification of Legg-Calve-Perthes disease

A lateral pillar is not involved B <50% of lateral pillar is affected C >50% of lateral pillar is affected What is lateral pillar? Lateral 15 to 30% of epiphysis is called the lateral pillar

Salter-Thompson classification of Legg-Calve-Perthes disease

A less than 50% of epiphysis involved B fracture of >50% of span of epiphysis

Catterall classification of Legg-Calve-Perthes disease

I involvement of anterior epiphysis without metaphyseal reaction, sequestrum or subchondral fracture line. < 25% epiphysis is involved II more extensive or severe involvement of anterior epiphysis, preservation of medial and lateral segments. Sequestrum present, with anterolateral metaphyseal reaction. Subchondral fracture line that doesn’t extend to the apex of femoral epiphysis. Less than half of…

Mitchell staging system for avascular necrosis

Class A osteonecrotic lesion shows signal similar to fat – high on T1, intermediate on T2 Class B hips show signal of blood or hemorrhage (high on both T1 and T2) Class C hips show signal of fluid (low on T1, high on T2) Class D hips show signal of fibrous tissue (low on T1…

Neer classification of shoulder impingement syndrome

Stage 1: tendon edema and hemorrhage Stage 2: fibrosis and tendinitis  Stage 3: partial or complete tear of rotator cuff. Associated anterior acromial spurring, or greater tuberosity excrescence. Burial thickening, fibrosis. Greater tuberosity sclerosis. 

Snyder classification of complete rotator cuff tears

0 tear lacks full thickness communication between bursal and articular surfaces I small complete tear (puncture) II moderate < 2 cm tear involving one tendon without retraction III large 3-4 cm complete tear involving entire tendon with minimal retraction of torn edge IV massive tear involving two or more cuff tendons, associated retraction and scarring…

Grading of partial rotator cuff tears (depth)

1 < 3 mm deep 2 3 – 6 mm deep, < 50 % of cuff thickness involved 3 high grade partial tear > 6 mm deep, > 50 % cuff thickness involved

Snyder grading of partial rotator cuff tears

0 Normal I minimal superficial bursal or synovial irritation or mild capsular fraying in small localized area (< 1 cm) II fraying and failure of some rotator cuff fibres with synovial bursal or capsular injury (< 2 cm) III fraying and fragmentation of tendon fibres usually involving whole surface of a cuff tendon, mostly supraspinatus…

Snyder classification of acromial thickness

Classification of acromial thickness assessed at posterior margin of acromioclavicular joint Type A: thin, less than 8 mm  Type B: 8 to 12 mm Type C: thick, more than 12 mm

Non-ossifying fibroma

Other name – fibrous cortical defect 10-20 years Asymptomatic Ossify with age Well-defined lytic cortical based lesion with narrow zone of transition showing thinning of cortex with no adjacent marrow edema or periostea reaction Do not touch lesions Read more Shah, Jignesh N., et al. “Pediatric benign bone tumors: what does the radiologist need to…

Simple bone cyst

Unicameral bone cysts 5-15 years age Intramedulary cavities with fluid that sometimes contains blood Asymptomatic  Low energy trauma can cause pathological fracture May show internal septa or fluid-fluid levels No post contrast enhancement Read more Shah, Jignesh N., et al. “Pediatric benign bone tumors: what does the radiologist need to know?: pediatric imaging.” RadioGraphics 37.3…

Osteoblastoma

Locally aggressive tumor Histologically similar osteoid osteoma distinguished by a size >1.5 cm Possible extra-osseous extension < 30 years age M:F = 2-3:1 Pain is not acute or severe. Not relieved by NSAIDs Femur and tibia commonest locations  Arise in medullary cavity Mostly in appendicular skeleton 30-40% in posterior elements of spine Rarely metastasizes Imaging …

Chondroblastoma

1% of all bone neoplasms 5-25 years M:F = 2.7:1 Mono-arthropathy Epiphysis of a long bone 50% around knee Proximal femur and humerus commonly involved Eccentric in epiphysis With partial closure of growth plate, extends to metaphysis Apophysis and sesamoid bones may be involved Calcaneus and talus may be involved Commonest tumor of patella Imaging …

Enchondroma

2nd-4th decade M=F Intramedullary neoplasm Lobules of benign hyaline cartilage Second most common benign chondral lesion after osteochondroma Tubular bones of hands and feet Asymptomatic, present when size increases or when pathological fracture occurs Proximal phalanges in most cases, then metacarpals, middle phalanges Less common in bones of feet, femur, tibia and humerus  Enchondroma protuberans…

Aneurysmal bone cyst

Cystic expansile lesion Often hemorrhagic Vertebral appendages, flat bones Metaphysis of long bones – femur, tibia, humerus Secondary to bone tumors in 30% cases Imaging Plain film Eccentrically without crossing growth plate Frequently multilocular Subtle cortical thinning Destructive expansile lesion in vertebral appendages, encroaching spinal canal D/D: telangiectatic osteosarcoma MRI Fluid-fluid levels due to hemorrhage…

Gorham disease

Rare Unknown etiology Childhood Osteolysis, often dramatic ‘vanishing bone’ disease Lymphovascular proliferation Shoulder, face, spine, pelvis involved Read more de Villiers, Johannes FK, and W. Ross Stevens. “Case 203: gorham disease.” Radiology 270.3 (2014): 931-935.