The Waldenström classification of Perthes disease refers to x-ray abnormalities and represents four temporal phases of the disease. These stages have been further subdivided in the modified Elizabethtown classification 2.
stage I: early
asymmetric femoral epiphyseal size (smaller on the affect...
Waldenström sign is the increased distance between the pelvic teardrop and the femoral head. It is a highly specific sign of a hip joint effusion.
>11 mm total distance or >2 mm difference compared to contralateral hip 1,2
measured between the lateral a...
Ward triangle refers to a radiolucent area between principal compressive, secondary compressive and primary tensile trabeculae in the neck of femur.
It should be differentiated from Babcock triangle.
History and etymology
Named for F O Ward after his original description of the region in 1838.
Wartenberg syndrome, also known as cheiralgia paresthetica, is due to compression of the superficial branch of the radial nerve in the distal forearm and a rare nerve compression neuropathy.
Patients present with pain and paresthesia along the dorsum of the distal forearm...
The wasp-waist sign is a radiographic appearance seen in patients with Klippel Feil syndrome. It results from fusion of the vertebral bodies such that the anteroposterior diameter at the level of the affected discovertebral joint is smaller than the diameter at the superior and inferior limits o...
The Wassel classification system is used to classify pre-axial polydactyly, also called radial polydactyly.
The classification system is based on the level of duplication from distal to proximal.
I: bifid distal phalanx
II: duplicated distal phalanx
III: bifid proximal phalanx
The water-lily sign, also known as the camalote sign, is seen in hydatid infections when there is detachment of the endocyst membrane which results in floating membranes within the pericyst that mimic the appearance of a water lily.
It is classically described on plain radiographs (mainly chest...
The Weber ankle fracture classification (or Danis-Weber classification) is a simple system for classification of lateral malleolar fractures, relating to the level of the fracture in relation to the ankle joint, specifically the distal tibiofibular syndesmosis. It has a role in determining treat...
Reporting a weightbearing foot series can be a daunting process if you are inexperienced and often results in the films being left for somebody else to report. This article attempts to demystify the whole process by providing a structured approach to their reporting.
A Weil osteotomy is a form of osteotomy performed in the foot. It is considered a common technique used in the treatment of lesser metatarsal deformities of the forefoot. It is designed to make a controlled shortening of the length of the metatarsal in the transverse plane.
The Weiss classification is one of the classification systems used for lateral humeral condyle fractures and is based on the degree of displacement measured on an internal oblique view of the elbow:
type 1: <2 mm displacement
type 2: 2-4 mm displacement
type 3: >4 mm displacement
The degree ...
Well-differentiated liposarcomas (WDLPS) or atypical lipomatous tumors (ALT) are locally aggressive adipocytic soft tissue neoplasms and are the most common form of liposarcomas.
Atypical lipomatous tumors/well-differentiated liposarcomas (ALT/WDLPS) are also termed ‘atypical lipom...
Werner syndrome is a progeroid rare autosomal recessive condition attributed to chromosome 8. It should not to be confused with similarly sounding Wermer syndrome.
Werner syndrome is characterized by
scleroderma-like skin changes such ...
The World Health Organization (WHO) classification of bone tumors is the most widely used pathologic classification system for such disorders. The current revision, part of the 4th edition of the WHO series, was published in 2013 and is reflected in the article below 1.
The World Health Organization (WHO) classification of soft tissue tumors is the most widely used pathologic classification system for such disorders. The current revision, part of the 5th edition of the WHO series, was published in 2020 and is reflected in the article below 1.
Wiberg classification is a system used to describe the shape of the patella based mainly on the asymmetry between the patellar medial and lateral facets on axial views of the patella. Increasing number type indicates a larger degree of asymmetry.
Wiberg type 1 or a
A widened intercondylar notch on knee radiographs is a sign associated with:
haemophilic arthropathy (most commonly bilateral)
juvenile rheumatoid arthritis (most commonly bilateral)
tuberculous arthropathy (usually unilateral) 3
The interpedicular distance, which is the distance measured between the pedicles on frontal/coronal imaging, can be widened in a number of situations.
conditions that can cause dural ectasia (can potentially cause widening)
Widening of the diploic space refers to expansion of the cancellous (spongy) bone between the inner and outer tables of the calvaria. The diploic space is the medullary cavity of the skull, and a location of normal physiologic hematopoiesis in adults. Thus, expansion of this structure most commo...
Wilson disease, also known as hepatolenticular degeneration, is a rare autosomal recessive disorder of copper metabolism affecting multiple systems.
Wilson disease is commonly found in Japan. It affects 1 in 30,000-40,000 individuals 12. 1 in 90 individuals are a heterozygous car...
Wilson disease, also known as hepatolenticular degeneration, is a multisystem disease, which rarely has musculoskeletal manifestations secondary to the accumulation of copper in the articular cartilage.
Reported manifestations include 1-3
Spondylolisthesis can be classified according to broad etiologies as described by Wiltse in 1981 1. Typically when reporting studies with spondylolisthesis the Wiltse type is merely stated without referring to its number, whereas the grade of spondylolisthesis is explicitly stated: e.g. "Grade 1...
Wimberger ring sign, often simply just called Wimberger ring, refers to a circular calcification surrounding the osteoporotic epiphyseal center of ossification in scurvy, which may result from bleeding.
It must not be confused with Wimberger sign, pathognomonic for congenital syphilis.
The Wimberger sign, also called Wimberger corner sign, refers to localized bilateral metaphyseal destruction of the medial proximal tibias. It is a pathognomonic sign for congenital syphilis.
It must not be mixed up with Wimberger ring sign seen in scurvy, which is sometimes also confusingly re...
Windswept knees refer to the appearance of a bilateral knee joint deformity where one knee is in valgus and the other is in varus. The name describes the position of the knees if the wind blew across the legs of a patient, causing this evocatively-named appearance.
Windswept pelvis fracture is a complex bony pelvic injury caused by a combination of unilateral AP compression (open book) injury with a contralateral lateral compression injury.
It occurs when the internal rotation of one iliac wing causes a unilateral sacral compression fracture, while the s...
The (absent) pedicle sign, also called the winking owl sign, occurs on plain radiograph of the spine when a pedicle is absent 5.
The term, winking owl sign, where the missing pedicle corresponds to the closed eye, the contralateral pedicle to the other round open eye, and the spinous process to...
The Winquist classification of femoral shaft fractures is based on fracture comminution and was proposed by Winquist in 1980. This classification is used with regards to management decision making, in determining whether a fracture requires an intramedullary nail or open reduction.
Type 0: no ...
Wolff's law summarizes the dynamic nature of the 3D microarchitecture of bone. Mechanical forces (or the lack of them) dynamically alter the thickness of cortical bone and the thickness and orientation of trabeculae.
Lack of sufficient mechanical loading (e.g. bed rest) results in resorption a...
Wormian bones (also knows as intrasutural bones) is the name given to the additional small bones sometimes found between the cranial sutures of the bones of the skull vault, most commonly in relation to the lambdoid suture. Some reserve the term Wormian bones to just the intrasutural bones proxi...
A mnemonic to remember ten of the numerous conditions associated with Wormian bones is:
O: osteogenesis imperfecta
K: kinky hair syndrome
C: cleidocranial dysostosis
O: otopalatodigital syndrome
Wrisberg rips, also known as zip tears or zipper tears, are longitudinal vertical meniscal tears. They occur at the junction of the ligament of Wrisberg and the posterior horn of the lateral meniscus and are commonly associated with anterior cruciate ligament tears 1.
The ligament o...
The wrist is a complex synovial joint formed by articulations of the radius, the articular disc of the distal radioulnar joint and the carpal bones.
Somewhat confusingly, the term carpus can be used as a synonym for the wrist joint as a whole, or in a more restricted sense to refer...
Wrist arthrocentesis refers to the aspiration of an effusion in the radiocarpal joint. It serves primarily as a diagnostic modality to determine fluid composition, and may function secondarily to reduce pain associated with capsular stretch. The dynamic, ultrasound-guided technique will be descr...
The carpal bridge view an additional view of the three view series of the wrist and carpal bones. It is a specialized projection that involves keeping the patient's wrist in flexion.
The carpal bridge view is requested to assess the dorsal aspect of the scaphoid, lunate and the tri...
The carpal tunnel view is an axial projection to demonstrate the medial and lateral prominences and the concavity.
This carpal tunnel view is seldom performed however it can be utilized to investigate potential hook of hamate, pisiform and trapezium fractures.
The clenched fist view is an additional projection used to evaluate suspected widening of the scapholunate interval, often performed bilaterally it is a functional view that requires the patient to clench both hands.
patient is seated in front of the table
both hands are pl...
The horizontal beam lateral wrist view is a modified lateral projection when performing the three view series of the wrist and carpal bones in trauma
This is not a requested view, rather an adaptation to a tricky situation. Most often this projection is conducted on patients who ar...
The lateral wrist view is part of a three view series of the wrist and carpal bones. It is the orthogonal projection of the PA wrist.
The lateral wrist radiograph is requested for myriad reasons including but not limited to trauma, suspected infective processes, injuries the distal...
The intrinsic and extrinsic wrist ligaments play a vital role in the stability of the wrist joint. There are numerous ligaments but included below are the most clinically significant. Wrist ligaments are best assessed with dedicated wrist MRI.
intrinsic ligaments (only attach to ...
The oblique wrist view is part of a three view series of the wrist and carpal bones. It is not generally performed in follow-up studies unless specifically requested.
The oblique wrist radiograph is requested for myriad reasons including but not limited to trauma, suspected infecti...
The PA wrist view is part of a three view series of the wrist and carpal bones. Although performed PA the view can often be referred to an AP view.
The PA wrist radiograph is requested for myriad reasons including but not limited to trauma, suspected infective processes, injuries t...
The MRI wrist protocol encompasses a set of MRI sequences for the routine assessment of the wrist joint.
Note: This article aims to frame a general concept of an MRI protocol for the assessment of the wrist. Protocol specifics will vary depending on MRI scanner type, specific hardware and softw...
The wrist PA radial deviation view is specialized projection employed to better demonstrate the carpal bones that lay on the ulnar aspect of the wrist.
Suspected abnormality at the ulnar aspect of the wrist, or in conjunction with a PA and ulnar deviation view to assess carpal move...
Wrist radiographs are ubiquitous in the emergency departments. They are commonly performed in the pediatric and elderly populations after a fall on an outstretched hand as well as in patients after higher force trauma. Moreover, they may be performed as part of a skeletal survey looking for meta...
Wrist radiographs are ubiquitous on any night of the week in emergency departments, especially when pavements are icy!
Choosing a search strategy and utilizing it consistently is a helpful method to overcome common errors seen in diagnostic radiology. The order in which you ...
Wrist x-rays are commonly used for the assessment of the wrist following trauma. This is usually a fall onto an outstretched hand.
It is useful to have a systematic approach; I tend to start proximally and work distally looking at structures on both views together:
The wrist radiograph checklist is just one of the many pathology checklists that can be used when reporting to ensure that you always actively exclude pathology that is commonly missed; this is particularly helpful in the examination setting, e.g. the FRCR 2B rapid-reporting.
This is a basic article for medical students and other non-radiologists
Wrist radiographs are commonly used for the assessment of the wrist following trauma.
distal radius and ulna have smooth joint surface
carpal arcs are smooth
carpal bones do not overlap
The wrist series is comprised of a posteroanterior, oblique, and lateral projection. The series examines the carpal bones that are consisting of the scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate and hamate. It also examines the radiocarpal and distal radiocarpal joint al...
This is a basic article for medical students and other non-radiologists
A wrist series (or wrist x-ray) may be performed for a multitude of reasons. However, they are most commonly used in the assessment of trauma, by clinical teams within the Emergency Department or Orthopedic service.
The xiphisternal joint (or more rarely, the sternoxiphoid joint) is a symphysis between the inferior margin of the body of the sternum and the superior margin of the xiphoid process. In most people it ossifies with age, usually becoming fully fused by the age of 40 years, forming a synostosis.
There is considerable anatomic variation in the shape of the xiphoid of the sternum:
xiphoid ending is classified as single, double, or triple.
xiphoid size varies (e.g. elongated process)
xiphoid morphology (e.g. ventral or dorsal deviation, hook-like, reverse S-shape).
Yaws, also known as framboesia, is a tropical disease produced by the Treponema pallidum subspecies pertenue.
Yaws is a tropical disease. Infections have declined dramatically over the last century, however the disease is still present in several countries in Africa and Asia 1. Y...
The Young and Burgess classification is a modification of the earlier Tile classification 1. It is the recommended 5 and most widely used classification system for pelvic ring fractures.
It takes into account force type, severity, and direction, as well as injury instability.
Three basic mech...
The yo-yo on a string sign denotes the characteristic appearance of the torn, proximally retracted and superficially displaced ulnar collateral ligament (UCL) due to a Stener lesion.
The sign occurs as a consequence of the tear of the ulnar collateral ligament of the thumb (gamekeepe...
Yunis Varón syndrome is a rare skeletal dysplasia. It is thought to be autosomal recessive.
severe neurologic impairment include small cerebellar vermis and dandy walker malformation
diastasis of sutures
The Z deformity is one of the musculoskeletal manifestations of rheumatoid arthritis in hand:
radial deviation at the wrist
ulnar deviation of the digits, and often
palmar subluxation of the proximal phalanges
A mnemonic to remember the features of Z deformity of the hand in rheumatoid arthritis is:
Consider mnemonic to be pronounced "word up" to help remember it.
WR: wrist radial deviation
DU: digits ulnar deviation
PP: proximal phalanges palmar subluxation
The zebra stripe sign occurs where children with osteogenesis imperfecta have been treated with cyclical bisphosphonate therapy, e.g. pamidronate. When the drug is delivered in cycles, dense bone is formed while treatment is being given. This results in dense stripes across the metaphyses of bon...
Zimmerman-Laband syndrome is a rare congenital syndrome, characterized primarily by gingival hypertrophy and skeletal abnormalities.
The molecular basis of the syndrome is currently unknown. An autosomal dominant mutation with a high mutation rate and rare instances of germinal mosa...
The zona orbicularis are circular fibers of the hip joint capsule and form a collar around the femoral neck. Though partly blended with the pubofemoral and ischiofemoral ligaments, these fibers are not directly attached to bone.
The zone classification of flexor tendon injuries divides injuries into five zones based on anatomical location. It is the most widely used flexor tendon injury classification system (c. 2007) 1.
Flexor tendon injuries were classified into five zones by Kleinart and Verdan in 19...
Z-scores are a way to translate individual data points into terms of a standard deviation.
Z = (X - Xbar) / σ
X: individual data point
Xbar: the arithmetic mean
σ: the standard deviation
The purpose of the Z-score is to allow comparison between values in different normal distributions. Two...
The zygoma (also known as zygomatic bone or malar bone) is an important facial bone which forms the prominence of the cheek. It is roughly quadrangular in shape.
Zygoma has three surfaces, five borders, and two processes.
anterolateral surface is convex, pierced at its...
The zygomaticus major muscle is a member of the buccolabial muscle group of the upper lip, a subset of the facial muscles 1. It joins with the muscle fibers of levator anguli oris, orbicularis oris and the more deeply placed muscular bands to move the side of the mouth upwards and sideways durin...
The zygomaticus minor muscle is a member of the buccolabial muscle group of the facial muscles. Together with the levator labii superioris alaeque nasi and levator labii superioris muscles it is one of the main elevators of the lip, exposing the maxillary teeth 1. Along with its other action of ...