Flashcards in musculoskeletalradiologyflash Deck (197):
4 features that suggest bone malignancy?
Cortical destruction. Periostitis. Orientation or axis of the lesion. Zone of transition.
Benign periostitis features?
Thick, wavy, uniform, or dense periostitis. Due to low-grade chronic irritation that gives periosteum time to lay down thick new bone.
Aggressive periostitis features?
Lamellated (onion-skinned), amorphous, or sunburst-like. Periosteum does not have time to consolidate.
Zone of transition in bony lesions?
Border of lesion with normal bone. Narrow: Well-defined (benign). Wide: Imperceptible (aggressive).
Destructive lesions with sclerosis from tumor new bone formation or reactive sclerosis. Occur almost exclusively in children and young adults (less than 30 years old).
Parosteal osteosarcoma features?
Arises from periosteum. Grows outside one, often wrapping around diaphysis without breaking cortex. Occurs in older age group than central osteosarcomas. Not as aggressive central osteosarcomas. Posterior distal femur is common location.
May mimic an early parosteal osteosarcoma of the posterior femur near the knee.
Cortical desmoid tumor. Myositis ossificans.
Ewing sarcoma features?
Permeative (multiple small holes) lesion in long bone diaphysis. May have onion-skin, sun-burst, or amorphous periostitis.
Cassic differential diagnosis for a permeative lesion in a child?
Ewing sarcoma. Infection. EG.
Bony or soft tissue mass with amorphous, snowflake calcification in an older patient (>40 years). Can't distinguish between enchondromas and low-grade chondrosarcomas.
Malignant Giant Cell Tumor
Benign and malignant giant cell tumors appear identical. If metastasizes (often to lung) then is malignant.
Lytic tumor without osteoid or chondroid matrix. May be permeative to a fairly well-defined area of lysis. Tend to predominate in fourth decade. May have a bony sequestrum.
Malignant fibrous histiocytoma
Common soft tissue tumors. In bone, appear identical to fibrosarcomas: Variable lytic lesion. May have bony sequestrum.
Half-grade fibrosarcoma. More common in soft tissue than bone. Usually are well defined lytic lesions when in bone. Often have benign periostitis with thick spicules.
Primary lymphoma of bone (reticulum cell sarcoma)
Similar appearance to Ewing sarcoma (permeative or moth-eaten). Occur in older age group than Ewing sarcoma.
Classic differential diagnosis for an expansile, lytic metastasis
Renal cell carinoma. Thyroid carinoma.
Two most common soft tissue tumors
Malignant fibrous histiocytoma. Liposarcoma.
Synovial sarcomas or synoviomas features?
Often adjacent to joints. Typically homogeneously T2 bright. May mimic fluid collection.
Synovial osteochondromatosis features?
Benign joint lesion. Synovial metaplasia leading to multiple calcific cartilaginous loose bodies in a joint. 20% do not calcify. May mimic pigmented villonodular synovitis.
Pigmented villonodular synovitis features?
Rare chronic inflammatory process causing synovial proliferation. Joint swelling, pain, occasionally joint erosions. No calcifications. Low T1 and T2 synovial signal (hemosiderin deposits). Rare chronic inflammatory process causing synovial proliferation.
Soft tissue Hemangioma features?
Phleboliths. Often cause cortical holes (pseudopermeative) in adjacent bone. May mimic permeative or moth-eaten pattern.
Predental space should not measure more than?
Jefferson fracture features?
Blow to top of head. C1 ring fracture, lateral masses of C1 must extend beyond margins of C2 body.
Rotatory fixation of the atlantoaxial joint?
Atlantoaxial joint becomes fixed. C1?C2 bodies move en mass, instead of rotating on one another.
Fracture of C6 or C7 spinous process, relatively innocuous.
Unstable, serious fracture of posterior elements of C2 usually with C2 anterolisthesis on C3. Caused by hyperextension and distraction (head against dashboard).
Disruption of posterior C-spine ligaments with anterior vertebral body compression. Usually associated with spinal cord injury.
Unilateral Locked Facets
Rupture of facet joint ligaments with dislocation due to severe flexion with some rotation. Facets are locked in an overriding position.
Seatbelt spine injury
Hyperflexion at the waist (lap belt). Distraction of posterior elements and ligaments with anterior vertebral body compression. Usually involves T12, L1, or L2.
Break or defect in pars interarticularis portion of lamina.
Further collapse of an acute unprotected wedge compression fracture. Results in severe neurologic deficits. Typically occurs 1 to 2 weeks after initial trauma.
fracture at base of thumb extending into carpometacarpal joint.
Comminuted fracture of thumb base extending into carpometacarpal joint.
Mallet finger or baseball finger
Avulsion injury at distal phalanx base where extensor digitorum tendon inserts.
Avulsion of thumb ulnar collateral ligament at the ulnar aspect of first metacarpophalangeal joint.
Failure to diagnose and treat lunate dislocation can result in?
Permanent median nerve impairment. Nerve can get impinged by volarly displaced lunate.
Rotary subluxation of the navicular
Rupture of scapholunate ligament. Scaphoid (navicular) rotates dorsally. Widened space between scaphoid and lunate.
__________ is often associated with Kienbock malacia.
Negative ulnar variance.
Positive ulnar variance has an increased incidence of
Triangular fibrocartilage tears.
Fracture of distal radius and ulna with dorsal angulation of distal forearm and wrist.
Facture of ulna with dislocation of proximal radius.
Fracture of radius with dislocation of distal ulna.
Bony deformities of anterior shoulder dislocation?
Hill-Sachs deformity: indentation on posterosuperior humeral head. Bankart deformity: Bony irregularity or fragment off inferior glenoid.
Permeative lesion in patient less than 30 years?
Ewing sarcoma. Infection. Eosinophilig granuloma.
Permeative lesion in patient > 40 years?
Multiple myeloma. Metastatic carcinomatosis. Primary lymphoma.
Subperiosteal bone resorption sites in hyperparathyroidism?
Radial aspect of middle phalanges. Medial aspect of proximal tibia. Sacroiliac joints. Distal clavicle.
Calcification of the sacrotuberous ligament is characteristic for
Differential for periostitis in a long bone without an underlying bony abnormality
Hypertrophic pulmonary osteoarthropathy. Venous stasis. Thyroid acropachy. Pachydermoperiostosis. Trauma.
Idiopathic thickening of cortical new bone. Accumulates near ends of long bones (dripping candle wax). Can affect several adjacent bones. May be symptomatic.
Common Causes of Avascular Necrosis
Trauma. Steroids. Aspirin. Collagen vascular diseases. Alcoholism. Idiopathic causes.
Don't touch lesions?
Myositis ossificans. Avulsion injury. Cortical desmoid. Trauma. Discogenic Vertebral Sclerosis. Fracture. Pseudodislocation of Humerus.
Radiologic appearance of myositis ossificans
Circumferential calcification with a lucent center (malignancy may have calcified or ossific center).
These injuries can have an aggressive radiographic appearance and are located at ligament and tendon insertion sites
Occur only on posteromedial epicondyle of femur. May result from avulsion of adductor magnus muscle.
Geodes can occur in what conditions?
Trauma. Calcium pyrophosphate dihydrate crystal disease. Rheumatoid arthritis. Avascular necrosis.
Discogenic Vertebral Sclerosis?
Variant of a Schmoral node. Often a sclerotic lesion adjacent to endplate. Associated disk space narrowing and osteophytosis.
Dorsal Defect of the Patella?
Lytic defect in upper outer quadrant of patella. May mimic pathologic process.
Pseudocyst of the humerus
Anatomic variant of increased cancellous bone near greater tuberosity. May mimic a lytic pathologic lesion.
Unfused dens. Smooth, often well-corticated, inferior dens border. Hypertrophied, densely corticated anterior arch of C1. May move anterior to C2 body with flexion. Can mimic a fractured dens.
Unicameral bone cysts treatment?
Curettaged and packed to prevent fracture. Those occuring in the calcaneus, however, should be left alone.
Bone infarct features?
May be patchy, mixed lytic-sclerotic or even resemble permeative process. Typically occur in metadiaphyses. Multiple bone infarcts consider sickle cell anemia or systemic lupus erythematosus.
Failure of endochondral bone formation. Narrowing of caudal interpedicular distances. Short long bones with normal width.
Hypertrophic Pulmonary Osteoarthropathy features?
Finger clubbing. Extremity periostitis.
Multiple Hereditary Exostosis
Multiple osteochondromas or exostoses. Nearly always involves knees. Undertubulation (widened bone diameter) present at site of exostosis.
Central beak or anterior bony projection off vertebral bodies?
Inferior bony projections extending anteriorly off the vertebral bodies?
Characteristic finding in all of the mucopolysaccharidoses (Hurler, Hunter, Morquio).
Notch at base of fifth metacarpal.
Painful sclerotic cortical lesion with lucent centered nidus. Occurs in patients younger than 30. Nidus is surgically removed or thermally ablated. May mimic osteomyelitis. Bone scan double-density sign versus photopenic area for osteomyelitis.
Aka Voorhoeve disease. Multiple 2- to 3-mm-thick linear sclerotic bands aligned parallel to bone long axis. Usually affects multiple long bones. Generally is asymptomatic.
Hereditary, asymptomatic disorder. Multiple small (3 to 10 mm) sclerotic bony densities. Primarily involves ends of long bones and pelvis. May mimic diffuse osteoblastic metastases.
Rare, familial disease. Skin thickening of face and extremities, finger clubbing, widespread periostitis.
Sarcoidosis bony findings?
Lacelike pattern of cortical bony destruction of multiple phalanges. May affect both hands. May have skin nodules.
Transient Osteoporosis of the Hip
Painful hip osteoporosis and no other finding. Self-limited with full resolution.
Benign, bony cystic lesion differential?
FEGNOMASHIC. Fibrous dysplasia. Enchondroma, EG. Giant cell tumor. Nonossifying fibroma. Osteoblastoma. Metastases, Myeloma. Aneurysmal bone cyst. Solitary bone cyst. Hyperparathyroidism. Infection. Chondroblastoma, Chondromyxoid.
Benign lytic lesions in patients younger than 30 years?
Eosinophilic granuloma. Aneurysmal bone cyst. Nonossifying fibroma. Chrondoblastoma. Solitary bone cyst.
Benign lytic lesions that have no pain or periostitis?
Fibrous dysplasia. Enchondroma. Nonossifyuing fibroma. Solitary bone cyst.
Fibrous dysplasia discriminator(s)?
No periosteal reaction.
Calcifications present (except phalanges). Painless (no periostitis).
Eosinophilic granuloma discriminator(s)?
Younger than 30 years.
Giant cell tumor discriminator(s)?
Epiphyses closed. Abuts articular surface (long bones). Well defined with nonsclerotic margin (long bones). Eccentric. Rules do not apply to flat bone GCTs.
Nonossifying fibroma discriminator(s)
Younger than 30 years. Painless (no periostitis). Cortically based.
Mention with ABC, especially in posterior elements of spine.
Metastatic disease and myeloma discriminator(s)?
Older than 40 years.
Aneurysmal bone cyst discriminator(s)?
Expansile. Younger than 30 years.
Solitary bone cyst discriminator(s)?
Central. Younger than 30 years.
Hyperparathyroidism (brown tumor) discriminator(s)?
Must have other evidence of hyperparathyroidism.
Younger than 30 years. Epiphyseal.
No calcified matrix.
Automatics that are mentioned for benign lytic lesions in patients younger than 30?
Infection. Eosinophilic granuloma.
Automatics that are mentioned for benign lytic lesions in patients older than 40?
Infection. Metastatic disease. Myeloma.
Benign lytic epiphyseal bone lesions?
Infection. Giant cell tumor. Chondroblastoma. Geode.
Differential for benign lytic rib lesion?
(FAME). Fibrous dysplasia. Aneurysmal bone cyst. Metastatic disease and myeloma. Enchondroma and eosinophilic granuloma.
Multiple benign bony lytic lesion differential?
(FEEMHI). Fibrous dysplasia. Eonsinophilic granuloma. Enchondroma. Metastatic disease and myeloma. Hyperparathyroidism (brown tumors). Infection.
Age and malignant bone tumor groups?
1-30: Ewing sarcoma. Osteogenic sarcoma. 30-40: Giant cell tumor. Parosteal sarcoma. Fibrosarcoma. Malignant fibrous histiocytoma. 1' lymphoma of bone. > 40: Chondrosarcoma. Metastatic disease. Myeloma.
Fibrous dysplasia features?
No periostitis, unless fracture. May be monostotic or polyostotic. Predilection for pelvis, proximal femur, ribs (lytic posterior ribs, sclerotic anterior ribs), skull. When in pelvis proximal femur involved. McCune-Albright syndrome: Polyostotic fibrous dysplasia, cafe-au-lait spots, precocious puberty. Adamantinoma: Tibial lesion that resembles fibrous dysplasia. Cherubism: Multiple fibrous dysplasia lesions in the jaw.
Contain calcified chondroid matrix, except when in phalanges. May cause endosteal scalloping. No periostitis. Difficult to distinguish from chondrosarcoma. Ollier disease (multiple enchondromas). Maffucci disease (multiple enchondromas with soft-tissue hemangiomas).
Eosinophilic granuloma features?
Any lesion in patient under 30 years. May be polyostotic. May have soft-tissue mass. May have bony sequestrum.
Nonossifying fibroma features?
Fibrous cortical defect (if less than 2cm). Asymptomatic (no periostitis). Metaphyseal. Emanate from cortex. 75% have thin sclerotic border that is scalloped and slightly expansile. Less than 30 years of age. Heal with sclerosis.
Rare. Simulate ABCs. Expansile, soup-bubbly. Commonly occur in posterior elements of spine.
Differential of lytic lesion of posterior elements of spine?
Osteoblastoma. ABC. TB. Metastasis.
Normal shoulder, humeral head slightly overlaps glenoid. Absence of crescent sign is often seen with posterior shoulder dislocation.
Traumatic hemarthrosis displaces the humeral head ____________ on the AP film.
What lines should be inspected for a suspected sacral fracture on a plain film?
Rectus femoris avulsion occurs at what bony landmark?
Anterior inferior iliac spine.
Erosions are ordinarily not seen in DJD, except in certain joints such as?
Symphysis pubis. Sacroiliac. Temporomandibular joint. Acromioclavicular joint.
Hallmarks of DJD are?
Sclerosis. Joint space narrowing. Osteophytosis.
Sclerosis in a weight-bearing bone that has a horizontal or oblique linear pattern?
Stress fracture until proved otherwise.
Cross-table lateral plain film of the knee that shows a fat-fluid layer, indicates?
Intraarticular fracture with bone marrow within joint.
In ruling out Lisfranc fracture, medial border of second metatarsal should line up with?
Medial border of second cuneiform.
When the Bohler angle becomes less than 20 degrees?
Calcaneal fracture should be considered.
Only disorder that will cause osteophytes without sclerosis or joint space narrowing
Diffuse idiopathic skeletal hyperostosis, DISH.
Primary osteoarthritis features?
Familial. More common in women. Symmetric and bilateral: DIP and PIP joints, base of thumb involement.
Condition with severe osteoporosis of the hands, as well as erosions.
Erosive osteoarthrits, aka Kellgren arthritis.
Diseases in Which Geodes Are Found
Degenerative joint disease. Rheumatoid arthritis. Calcium pyrophosphate dihydrate deposition disease (CPPD). Avascular necrosis.
Radiographic hallmarks of Rheumatoid arthritis?
Soft tissue swelling. Osteoporosis. Joint space narrowing. Marginal erosions. Affects proximal hands symmetrically.
With rheumatoid arthritis the femoral head tends to migrate _________, whereas in osteoarthritis, it tends to migrate ________.
Axially (RA). Superolaterally (OA).
Seronegative, HLA-B27-positive spondyloarthropathies?
Ankylosing spondylitis. Inflammatory bowel disease. Psoriatic arthritis. Reiter syndrome.
Characterized by bony ankylosis, proliferative formation of new bone, and predominantly axial (spinal) involvement?
Syndesmophyte is a
Paravertebral ossificatio. Runs vertically, whereas an osteophyte runs horizontally.
Causes of High-Riding Shoulder
Rheumatoid arthritis. Calcium pyrophosphate dihydrate deposition disease (CPPD). Torn rotator cuff.
Syndesmophyte features of HLA-B27 spondyloarthropathies?
Ankylosing spondylitis: Marginal, symmetric. Psoriatic and Reiter syndrome: Nonmarginal, asymmetric.
SI joint involvement of HLA-B27 spondyloarthropathies?
Ankylosing spondylitis and inflammatory bowel disease: Bilateral, symmetric SI joint disease. Reiter syndrome and psoriatic arthritis: Unilateral or bilateral SI joint disease.
Psoriatic arthritis findings in the hands and feet
Distal predominance. Proliferative erosions. Soft tissue swelling. Periostitis.
Fuzzy margins with wisps of periostitis emanating from them. Seen in psoriatic arthritis.
Reiter syndrome causes identical changes in every respect to psoriatic arthritis, with the exception that
Reiter syndrome involves the feet more commonly than the hands. Interphalangeal joint of great toe is commonly affected.
As many as _____% of patients with gout concomitantly have CPPD.
Hallmarks of Gout?
Well-defined erosions (sclerotic margins, overhanging edges). Soft tissue nodules (may calcify in renal failure). Random distribution. No osteoporosis.
Pseudogout, classic triad:
Pain. Cartilage calcification. Joint destruction.
Most Common Location of Chondrocalcinosis in Calcium Pyrophosphate Dihydrate Deposition Disease
Knee. Triangular fibrocartilage of wrist. Symphysis pubis.
DJD of CPPD has a proclivity for what joints?
Shoulder. Elbow. Radiocarpal joint. Metacarpophalangeal joints. Patellofemoral joint.
Three diseases that have a high degree of association with CPPD.
Primary hyperparathyroidism. Gout. Hemochromatosis.
Striking radiographic hand abnormalities in collagen vascular diseases (scleroderma, SLE, dermatomyositis, MCTD)?
Osteoporosis. Soft tissue wasting.
Systemic lupus erythematosus characteristically has severe _______ deviation of the phalanges
Classic radiographic changes of hemochromatosis of the skeleton?
DJD involving 2nd - 4th metacarpophalangeal joints. 50% also have CPPD,
Classic triad of neuropathic or Charcot joint?
Destruction. Dislocation. Heterotopic new bone.
Most commonly seen Charcot joint today is
First and second tarsometatarsal joints (Lisfranc fracture) in diabetics.
Classic findings for JRA and hemophilia are
Epiphyseal enlargement. Widening of knee intercondylar notch. Gracile diaphyses.
Synovial osteochondromatosis most commonly affects what joints?
Knee. Hip. Elbow.
What occurs in tumefactive synovial chondromatosis?
Loose bodies are tightly packed in a joint. May look like tumor at MR.
PVNS looks radiographically identical to
Noncalcified synovial osteochondromatosis, yet much less common.
Sudenck atrophy is also known as
Shoulder-hand syndrome. Reflex sympathetic dystrophy.
Sudeck atrophy radiographic findings
Severe, patchy osteoporosis and soft tissue swelling. Typically affects hands or feet.
Radiographic sign for a knee effusion
10 mm or more displacement of suprapetallar fat pad and anterior femoral fat pad.
Signs of avascular necrosis?
Joint effusion. Patchy or mottled density. Subchondral lucency. Collapse of articular surface. Joint fragmentation. Only one side of joint involved.
Avascular necrosis of lunate?
Flattening and sclerosis of tarsal navicular thought to be due to avascular necrosis in children?
Form of AVN that is smaller and more focal is known as?
Common sites of osteochondritis dessicans?
Medial epicondyle of knee. Dome of talus. Capitellum.
Avascular necrosis of apophyseal rings of vertebral bodies is called
Avascular necrosis of metatarsal heads is called?
Avascular necrosis of femoral head?
Avascular necrosis of tibial tubercle is?
Osteoporosis versus osteomalacia?
Osteoporosis: Decreased bone quantity. Osteomalacia: Abnormally mineralized (normal quantity) bone.
Normal metacarpal cortical thickening should be approximately ____________ the thickness of the metacarpal
One fourth to one third.
Distinguishes permeative processes from pseudopermeative processes?
Permeative process: Solid cortex with permeative medullary space. Pseudopermeative process: Cortex is permeative (multiple small holes).
Differential diagnosis of pseudopermeative lesion?
Aggressive osteoporosis. Hemangioma. Radiation changes.
Only finding that is pathognomonic for osteomalacia
Looser fracture: Fracture through large osteoid seams. Occur in femur, pelvis, and scapula.
In children, osteomalacia is called rickets. Findings
Flared and irregular epiphyses. Long bones may bend.
Pathognomonic for hyperparathyroidism?
Subperiosteal bone resorption. Most commonly involves radial aspect of middle phalanges of hand.
Rugger jersey spine
Spine endplate osteosclerosis resembles stripes on rugby jerseys.
Few skeletal changes occur in hypoparathyroidism, but the following may be seen:
Calvaria may thickened. Basal ganglia calcification.
Failure of tissues to respond to PTH. Obesity, round facies, short stature, brachydactyly.
Acromegaly radiographic findings
Calvarial thickening. Enlarged sinuses. Enlarged sella turcica. Prognathic jaw. Hypertrophied distal phalanx tufts (spade appearance).
Thyroid acropachy features?
Periostitis of metacarpals and phalanges, particularly ulnar aspect of fifth metacarpal. Occurs in hyperthyroid patients post-thyroidectomy.
Differential Diagnosis of Diffuse Bony Sclerosis (Dense Bones)?
(Regular Sex Makes Occasional Perversions Much More Pleasurable And Fantastic). Renal osteodystrophy. Sickle cell disease. Myelofibrosis. Osteopetrosis. Pyknodysostosis. Metastatic carcinoma. Mastocytosis. Paget disease. Athletes. Fluorosis.
Renal osteodystrophy bony features?
Osteopenia. 10% to 20% exhibit osteosclerosis.
Sickle cell disease features?
Osteosclerosis. Bone infarcts. Step-off deformities (H-shape) of vertebral body endplates.
Progressive fibrosis of bone marrow in patients older than 50. Anemia. Splenomegaly. Extramedullary hematopoiesis.
Extremely dense bones. Bone-in-bone appearance of vertebral bodies. Sandwich vertebrae, densely sclerotic endplates.
Congenital cause of dense bones. Pathognomonic acroosteolysis with sclerosis (pointed chalk distal phalanges).
What metastases can cause diffuse osteosclerosis?
Prostate cancer. Breast cancer.
Features of Paget's disease?
Bony enlargement. thickened ileopectineal line. 3 distinct phases (lytic, sclerotic, mixed lytic-sclerotic,). Flame-shaped or blade-of-grass leading edge. Starts at end of a bone (except tibia).
Neurogenic muscle edema corresponding to a particular nerve. Suprascapular nerve: Supraspinatus, Infraspinatus. Axillary nerve: Teres minor, Deltoid. Acute pain followed by weakness. Associations: Vaccinations, Viral illness, General anesthesia.
Fluid in tendon sheath with normal underlying tendon.
Partial tendon tear. Focal or fusiform swelling of tendon with internal bright T2 signal. Thinning of tendon is a more severe form.
Intermediate, not fluid bright, signal within a tendon. Represents myxoid degeneration.
Can tenosynovitis occur in the Achille's tendon
No, Achille's tendon lacks a sheath.
Posterior tibial tendon inserts onto
Navicular. Second and third cuneiforms. Bases of second to fourth metatarsals.
Posterior tibial tendonitis and rupture are commonly encountered in patients with
Runs just deep to PTT. Goes underneath neck of talus. Helps support talus and arch. When PTT tears stress is placed on spring ligament.
Thin fibrous structure that binds peroneus longus and brevis tendons to posterior distal fibula.
Split tear of peroneus brevis
V-shape (Chevron) or divided peroneus brevis tendon distal to fibula.
Unstable osteochondral defects
Surrounding or internal high T2 signal about or within osteochondral lesion.
Tumors that have a predilection for the foot and ankle
Synovial sarcomas (16%). Desmoid tumors. Giant cell tumors of tendon sheath.
Differential diagnosis for calcaneal tumors
Unicameral bone cyst. Epiphyseal equivalent: Giant cell tumor. Chondroblastoma. Infection.
Most common accessory muscles encountered around foot and ankle.
Accessory soleus. Accessory peroneus quartus muscles.
Fibular ankle ligaments
Superior group: Anterior and Posterior tibiofibular ligaments. Inferior group: Anterior and Posterior talofibular ligaments. Calcaneofibular ligament.
Conditions with high association with chronic tears of the lateral ankle ligaments
Chronic lateral ankle instability. Sinus tarsi syndrome. Anterolateral impingement syndrome.
Sinus tarsi syndrome
Torn ligaments of sinus tarsi. Results in subtalar instability. Granulation tissue (high T2, low T1) or scar (low T2, low T1) replaces normal fat (high T1) of sinus tarsi.
Anterolateral impingement syndrome
Synovial hypertrophy or scarring in lateral ankle gutter. Space between tibia and fibula bound by lateral ankle ligaments. Lateral ankle pain and inability to dorsiflex normally.
2 most common tarsal coalitions
Calcaneonavicular joint. Middle facet of talocalcaneal joint.
Large meniscus: Lens-shaped, wedged, flat and others. Lateral meniscus (3% population) more commonly involved than medial. More prone to tear. Can be symptomatic even without a tear.
Transverse knee ligament
Ligament running through Hoffa's fat-pad connecting both meniscal anterior horns. May mimic an anterior horn lateral mensicus tear.
Extends obliquely from medial femoral condyle to posterior horn lateral meniscus. Ligament of Humphry (passes in front of PCL). Ligament of Wrisberg (passes behind PCL).
Lateral collateral ligament (LCL) of the knee consists of three parts, posterior to anterior:
Biceps femoris tendon inserts onto head of fibula. Fibular collateral ligament (true lateral collateral ligament) extends from lateral femoral condyle and joint biceps femoris tendon to insert on head of fibula. Iliotibial band extends from fascia to blend into lateral retinaculum on the patella and inserts at Gerdy's tubercle of lateral tibia.