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The scala vestibuli commu- nicates with the middle ear through the oval window that is closed by the footplate of stapes purchase finast 5mg visa hair loss in men39 s warehouse. The scala tympani communicates with the middle ear through the round window Figs 2 discount 5mg finast mastercard hair loss 50 year old woman. It has three components namely hair cells buy generic finast 5 mg hair loss in men rolex, supporting cells and the fibres around the hair cells pass through the gelatinous membrane called the tectorial osseous spiral lamina into a long bony canal membrane purchase 5 mg finast with mastercard hair loss in men jokes. There are two types of hair cells, of modiolus (Rosenthal’s canal) which contains the outer and inner hair cells. The are supported by pillars of Corti that enclose inner hair cells are arranged in one row and a space called the tunnel of Corti. They develop earlier than contains a fluid called Cortilymph that resem- outer hair cells and are more resistant to bles perilymph in composition. The nerve damage by noise or ototoxic drugs and are Anatomy of the Ear 19 arrangement is necessary for the acoustic insulation of hair cells from inevitable noise arising in blood vessels. Energy producing metabolic processes depend upon the function of specific intracellular enzymes. Oxygen tension is highest (44-78 mm Hg) near the stria vascularis and lowest near the organ of Corti (16-20 mm Hg). They develop later than inner hair cells and are easily damaged by Tympanic Membrane noise or ototoxic drugs. Diameter perpendicular 8-9 mm Blood supply of the internal ear: The to manubrium arterial supply of the internal ear is derived Height of cone (inward 2 mm from the internal auditory artery. Middle Ear Cavity The organ of Corti has no direct blood supply and depends for its metabolic activ- Total volume 2. Secreted by stria vascularis or by the Saccus endolymphaticus adjacent tissues of outer sulcus. Approximately 3 Physiology of the Ear The pinna which plays a role of sound collec- The tympanic membrane and ossicles not only tion in some lower animals does not seem to conduct the sound but also increase its play this function in human beings. The perceptive neural mechanism which overcomes this resistance by increas- (transduction). The greater length of the handle of Functions of the Middle Ear Muscles malleus compared to the long process of The basic function of the intratympanic incus (1. Loud sounds reflexly The result of the two gains, the hydraulic stimulate the muscles, which cause stiffness ratio and the ossicular lever ratio (17 × 1. As these muscles This is how the middle ear functions as the have a latent period of contraction of 10 msec, sound pressure transformation mechanism these do not provide protection from sudden and helps in impedance matching of the explosive sounds. The reconstruction of the middle ear trans- Eustachian tube helps in aeration of the former mechanism and round window middle ear. Normally, an aerated middle ear protection form the principles of tympa- cavity is essential for proper functioning of the noplasty. Besides air conduction, the sounds are also The eustachian tube helps in equalisation transmitted through bone, which may be due of pressure in the middle ear. As the atmos- to vibration of the skull by the subject’s own pheric pressure decreases, as during ascent in sound waves, the free-field sound energy or an aeroplane, the air in the middle ear by application of the vibrating body directly cavity gets absorbed and a negative pressure to the skull. This can The stimulation of the sense organs by the be equalised by frequent swallowing move- bone conducted sounds occurs as a result of ments which open the eustachian tubes. Physiology of the Ear 25 Functions of the Mastoid Cellular System The function of cellularity of the mastoid is not very clear. It may be insulating chambers protecting the labyrinth from temperature variations. Volley theory (Wever’s theory): This theory The organ of Corti gets stimulated and results is a combination of place and telephonic in generation of cochlear microphonics. The low tones displace the whole of the basilar Pitch Discrimination in the Cochlea membrane and are represented in the There are different theories of hearing which auditory nerve by nerve fibre responses. Place theory (Helmholtz’s theory): According to this theory, the perception of pitch The vestibular system plays a role in main- depends on movements of the point of taining equilibrium in addition to visual and maximum displacement of the basilar proprioceptive mechanisms. Thus each pitch would cause Semicircular canals The canals are sensitive to vibration of its own place on the basilar changes of angular velocity. During angular theory assumes that pitch discrimination acceleration or deceleration, the endolymph depends upon the rate of firing of the due to its inertia lags behind and thereby action potentials in the individual nerve exerts pressure within the ampulla. As soon fibres, the frequency analysis is then done as the constant velocity of rotation is attained by the central nervous system. Once angular acceleration or decele- statoconial membrane, which is responsible ration ceases, the endolymph being still in for static labyrinthine reflexes resulting from motion, stimulates the crista ampullaris but centrifugal forces and also responsible for in the reverse direction. Utricle The hair cells of the utricular macula There is a constant discharge from the are stimulated by the gravitational pull on vestibular labyrinth conducted through the Physiology of the Ear 27 eighth nerve to the central vestibular connec- of the whole, which can still be elicited for tions which keep the cortex informed about several hours after total oxygen depriva- the changes in position and posture of head tion or death. This means that a sound wave as such does not potentials of the individual nerve fibres. There are several forms of sound distortion to which the ear, in common with other acous- Masking tic devices, is subjected. These are as follows: The masking of a tone by a louder sound of Frequency distortion The “preferential” trans- approximately similar frequency is called mission of certain frequencies as compared to ipsilateral direct masking. This mechanism is others occurs when the secondary system into independent of the central nervous system. Both simple and comp- mingling of the central connection of the two lex wave motions can be affected by ampli- ears. History of drug intake: Drugs like salicylates, aminoglycosides, quinine and cytotoxic Deafness or hearing impairment is an impor- drugs are known to be ototoxic. The various points to be noted are roundings are more prone to hearing the following. Duration: Deafness which is present since hearing if he or she has a hearing loss which birth may be due to genetic causes, due to can be helped by medical and/or by surgical prenatal intake of drugs like thalidomide treatment, or has learned speaking naturally or if the mother suffered from rubella as a partially hearing child or adult. Prolonged labour and tation measures like providing amplification otitis media, measles, mumps and menin- (hearing aid), and speech and auditory train- gitis during infancy are also important ings can help in restoring verbal communi- causes of deafness. Provided the treatment is started early Deafness of recent origin in adults may in life, such a person can be educated with be due to traumatic, inflammatory, neo- normal hearing children and in later life will plastic, vascular and metabolic causes. In has a severe hearing loss with little or no cochlear lesions patients do not hear at residual hearing. Such a person’s hearing is conversational intensity but get irritated by nonfunctional for ordinary purposes of life. When measured with an audiometer the Fluctuant deafness occurs in secretory hearing loss for speech is 82 dB or worse otitis media and Ménière’s disease. A deaf 30 Textbook of Ear, Nose and Throat Diseases person should be educated and trained in a may also be due to the infections of the exter- deaf school. The discharge may be serous, mucoid, mucopurulent, purulent, Tinnitus blood stained, or watery. Tinnitus is first important symptom of sali- Serous discharge is found in allergic otitis cylate poisoning. Mucopurulent discharge is com- periodic episodes of deafness and vertigo monly due to benign chronic suppurative constitutes Ménière’s syndrome. Wax in the otitis media and the extension of the disease external auditory canal, aero-otitis media, process to mastoid air cells. A purulent dis- infections of the ear, acoustic trauma and charge usually signifies an underlying bone otosclerosis may be associated with tinnitus. This type in ears and tinnitus are found in secretory of discharge may occur in otitis externa also. Blood-stained discharge is a feature of Vertigo malignancy, glomus jugular and granulations. The first thing to ascertain is whether the vertigo is Earache (Otalgia) really vertigo (a sense of rotation) or a synco- Pain in the ear may occur due to lesions in the pal attack in which the patient gets a blackout, ear itself or due to the conditions in the sur- falls momentarily and quickly regains con- rounding areas (referred otalgia) (Fig. Painful lesions of the ear include the Vertigo with a discharging ear indicates following: labyrinthitis. Via the greater auricular nerve and facial nerve: Cervical spine lesions, neck lesions (inflam- matory, traumatic, neoplastic, etc.
There are other types of carpal instability patterns that Ganglion is another cause for a focal swelling in the hand cheap finast 5 mg overnight delivery hair loss 20 year old female, are better detected more by physical examination; these but usually that occurs without underlying bone deformi- will not be covered here 5mg finast with visa hair loss from wen. Occasionally buy finast 5mg lowest price hair loss 1 year postpartum, a glomus tumor will cause a pressure Infection effect on bone effective 5 mg finast hair loss juicing recipes, especially on the distal phalanx under the nail bed. Infection should be suspected when there is an area of cortical destruction with pronounced osteopenia. It is not uncommon to have patients present with pain and Arthritis swelling, and clinically infection may not be suspected when it is chronic, as with an indolent type of infection Using the above scheme of analyzing the hand, wrist, and such as tuberculosis. Soft-tissue swelling is a key point musculoskeletal system , swelling can indicate cap- for this diagnosis as for other abnormalities of the wrist, sular involvement as well as synovitis. Therefore, the diagnosis of infection ation of alignment shows deviation of the fingers at the is most likely when there is swelling and associated os- interphalangeal and metacarpophalangeal joints in addi- teopenia as well as cortical destruction ,or even early fo- tion to subluxation or dislocation at the interphalangeal, cal joint-space loss without cortical destruction. Joint-space loss, the sites of erosions, and the sites of bone production are important to recognize. When iden- Neoplasia tifying the abnormalities, the metacarpophalangeal joint capsules, especially of the index, long and small fingers, When there is an area of abnormality, it helps to determine should be examined carefully to determine whether they the gross area of involvement, then look at the center of are convex, as occurs in for capsular swelling. If the center of the abnormality is in help in establishing whether this is primarily a synovial 20 L. Gilula arthritis, which in some cases exists in combination with Conclusions osteoarthritis. Synovial arthritis is supported by findings of bony destruction from erosive disease. The most com- Application of the the “A, B, C, D’S” system, together mon entities to consider for synovial-based arthritis are with an analysis of parallelism, abnormal overlapping ar- rheumatoid arthritis, and then psoriasis. If there is osteo- ticular surfaces and carpal arcs, can help analyze abnor- phyte production, osteoarthritis is the most common con- malities encountered in the hand and wrist, which can sideration, whereas osteoarthritis associated with erosive help in making a most reasonable diagnosis for further disease, especially in the distal interphalangeal joints, is evaluation of the patient. Punched-out or well- defined lucent lesions of bone, especially about the car- pometacarpal joints in well-mineralized bones, must also References be considered for the robust type of rheumatoid arthritis. Gouty destruc- Pennsylvania, pp 3 tion depends somewhat on where the gouty tophi are de- 2. There is a strong likelihood of renal osteodystro- Traumatic axial dislocations of the carpus. Bone resorption stability series: Increased yield with clinical-radiologic screen- can also take place intracortically and endosteally. Petersilge Department of Radiology, Orthopedic University Hospital Balgrist, Zurich, Switzerland Many exciting new advances in our knowledge of the hip labrum. Cam impingement is common in young and and its pathologic processes have occurred during the athletic males . Current topics of in- abutment is the result of an acetabular abnormality, of- terest include imaging of the acetabular labrum, ten a general over-coverage (coxa profunda) or local an- femoroacetabular impingement, fatigue and insufficiency terior over-coverage (acetabular retroversion). The first fractures, bone-marrow edema syndromes, and abnor- structure to fail with the pincer impingement type is the malities of the greater trochanter and its tendon. Continued pincer impingement re- sults in degeneration of the labrum and ossification of the rim, leading to additional deepening of the acetabu- lum and worsening of the over-coverage. Pincer im- Femoroacetabular Impingement pingement can result in chondral injury in the contre- coup region of the posteroinferior acetabulum. The repetitive mechanical con- impingement is seen more frequent in middle-aged flict occurring in flexion and internal rotation will lead women . Other findings include a reduced Cam impingement is caused by jamming of an ab- waist of the femoral neck and head junction, and normal junction of the femoral head and neck (usually changes at the acetabular rim, such as os acetabuli, or a deficiency of the femoral waist at the anterolateral herniation pits at the femoral neck (Fig. In pincer portion of the femoral neck) into the acetabulum during impingement, acetabular findings include conditions forceful flexion and internal rotation of the hip. This re- with a relatively too-large anterior wall of the acetabu- sults in abrasion of the acetabular cartilage or its avul- lum, such as the coxa profunda/protrusio acetabuli sion from the labrum and subchondral bone in a rather (Fig. Chondral avulsion, in turn, sign between the lateral outlines of the anterior and leads to tear or detachment of the principally uninvolved posterior acetabular wall). The medial border of the ac- etabulum (black arrowheads) extends medial to the Ilio-ischial line (arrow). Most patients present with antero- superior labral tears and degeneration of the labrum as- (Fig. The first line is drawn from the center of the circle of The a-angle helps to identify and quantify an abnor- the femoral head to the point where the circle leaves mal contour of the anterior femoral head-neck junction the anterior contour of the femoral head-neck junction. Imaging of the Painful Hip and Pelvis 23 The second line is drawn parallel through the center of Part of the gluteus minimus insertion is muscular and the femoral neck and the center of the circle of the inserts in the ventral and superior capsule of the hip femoral head. An angle over 55° indicates a significant Although pain over the lateral aspect of the hip has abnormal contour of the anterior femoral head-neck been commonly attributed to trochanteric bursitis, the junction . Despite simi- lar clinical presentations, treatment of these processes The hip joint, much like the glenohumeral joint, has can be quite different, emphasizing the need for accu- one of the widest ranges of motion in the human body. The typical appearance of this tear is a The greater trochanter serves as the main attachment circular or oval defect in the gluteus minimus tendon site for very strong tendons, facilitating complex move- that extends posteriorly into the lateral part of the glu- ment such as postural gait. The integrity of the greater trochanteric structures is therefore important for normal gait. The main tendon of the gluteus medius muscle most common joint-replacement performed in the has a strong insertion covering the posterosuperior as- United States after primary total knee replacement, pect of the greater trochanter. It runs from posterior to anterior and inserts at the include hardware failure, such as mal-alignment or lateral aspect of the greater trochanter. Parts of the glu- loosening of the prosthesis, and soft-tissue abnormali- teus medius run anteriorly and cover the insertion of ties, including infection, joint instability, trochanteric the gluteus minimus tendon. The imaging gluteus medius tendon is usually thin and may be al- workup usually focuses on evaluating hardware fail- most purely muscular. The main tendon of the gluteus ure; however, especially if a transgluteal approach has minimus attaches to the anterior part of the trochanter. Coronal T1- weighterd spin-echo im- age (left image) and T2- weighted fat saturated (right image) demon- strating a complete tear (curved arrow) of the gluteus medius tendon (arrowheads) 24 C. At the an- marily because of susceptibility artifacts related to the teroinferior and posteroinferior margins of the joint, the metallic implants. The labrum is normally of triangu- quality can be achieved in spin echo imaging by using a lar morphology and typically has low signal intensity on high bandwidth (at least 130 Hz/pixel), a high-resolution all imaging sequences . However, variations in signal matrix (512×512), sequences with multiple refocusing intensity and morphology do occur, including rounded pulses, and a frequency-encoding axis parallel to the long and flattened labra as well as absent labra [9-11]. Labral pathology is also commonly 6) and fatty atrophy of the gluteus medius and the poste- seen in patients with developmental dysplasia and those rior part of the gluteus minimus muscle are uncommon in with femoroacetabular impingement. These abnormalities are most common- ly located at the anterosuperior margin of the joint. Pitfalls in interpretation include the sulcus at the junc- tion of the labrum and the transverse ligament at the an- teroinferior and posteroinferior portions of the joint as well as the presence of a cleft or groove between the ar- ticular cartilage and the labrum. Stress and Insufficiency Fractures Stress and insufficiency fractures commonly involve the pelvis. Stress fractures are commonly identified in the proximal femur and typically occur along the medial as- pect of the femoral neck. Pubic rami stress fractures are one cause of groin pain, and imaging will help to differ- entiate these injuries from injuries to the anterior abdom- inal wall musculature and the adductor muscle origins [17, 18]. Common sites include the sacrum, pubic rami, and the ileum, including the supra-acetabular ileum. Insufficiency fractures of the subchondral portion of the femoral head have recently been recognized [19-21]. Previously, these lesions were often diagnosed as tran- sient osteoporosis of the hip.
Semin Musculoskelet Radiol mine whether symptoms are secondary to scarring or in- 2(4):397-414 8 cheap finast 5mg on-line hair loss in men journal. Hand Clin 18(1):149-159 osseous or muscular variants and anomalies finast 5 mg line hair loss treatment youtube, soft-tissue 9 cheap 5mg finast mastercard hair loss black women. Am J the two heads of the pronator teres and under the fibrous Roentgenol 175(4):1099-1102 10 purchase finast 5 mg online hair loss female. Radiology 204(1):185-189 a result of repeated pronation, forearm extension, and 12. J Bone Joint Surg Am 83-A(12):1823-1828 Motor neuropathy of the hand extensors is a dominant 13. Am J Microscopic histopathology of chronic refractory lateral epi- Roentgenol164(2):415-418 condylitis. Radiographics 22(5):1223-1246 terosseous nerve palsy caused by synovial chondromatosis of 7. First, look at Musculoskeletal trauma is common and the distal upper the soft tissues. On the lateral view, convexity of the dor- extremity is one of the most frequent sites of injury. When the distal radius is fractured, the pronator fat remain the primary diagnostic modality. It is therefore es- pad will be deformed and displaced, becoming convex in sential for radiologists who work in a trauma and emer- a palmar direction. A second but less frequently present gency setting to be familiar not only with the normal ra- fat pad is the scaphoid fat pad. When present, it should diographic anatomy of the hand and wrist but also with be relatively straight and lateral and parallel to the the range of injuries that can occur. Rogers, put it all quite simply in a few ly, a scaphoid fracture should be suspected. Thus, not only should we know where to that will be disrupted in injuries to the intercarpal joints. The key to the carpometacarpal joints is to look jections are used but are centered and collimated to cover at those joint surfaces that have been profiled by the X- the wrist area, from the metadiaphyses of the distal radius ray beam. If one side of a joint (carpal or metacarpal) is and ulna to the proximal metacarpal diaphyses. A fourth seen in profile, the other side of that same joint should be view, the so-called scaphoid view, should always be in- seen in profile and parallel to its mate. On the lateral view, the distal radial articular surface This view rotates the scaphoid about its short axis, pre- and proximal lunate articular surface should form paral- senting the waist of the bone in profile. The articular cartilage has approximately the same thickness throughout the carpus. If the apparent space be- tween any two carpal bones appears wider than the ap- parent space between the others, a ligament disruption has probably occurred. The joints most commonly affect- ed by ligament injuries are the scapholunate and lunotri- quetral joints. Therefore, the apparent space between the lunate and scaphoid and the lunate and triquetrum should always be carefully evaluated. In very small children, whose bones are rela- tively soft, buckle or torus fractures of the distal radius are the most common injuries. While most of these are obvious, the findings may be limited to very subtle angulation of the Fig. The arcs of Gilula, lazy M and capitate axis cortex, seen only on the lateral view. If one or more of As adolescents enter the growth spurt associated with these articulations are not parallel, the carpus has been puberty, their physes become weaker and subject to frac- dislocated or subluxed. The normal scapholunate angle lies between 30 in the Salter-Harris classification as follows: type 1, phy- and 60°. In general, these injuries are displaced and easy to recognize, with excep- tion of type 5 injuries. However, in some patients, partial auto-reduction may make a type 1 or 2 fracture difficult to find on the radiographs. The center of most frequent injury moves to the carpus, where fractures and dislocations are most likely to occur in the so-called zone of vulnerability (Fig. This zone runs in a curved man- ner across the radial styloid, scaphoid, capitate, triquetrum and ulnar styloid. Next in frequency are various dislocations and fracture dislocations, involving predominantly the midcarpal joint. Scaphoid fractures are important to consider in all injured wrists for two reasons. The scapholunate and capitate articulations capitolunate angles truly nondisplaced and may be difficult to see on radi- Radiology of Hand and Wrist Injuries 15 ture”. Conversely, if the palmar lip of the radius is fractured, the carpus will be displaced palmarly. While pure dislocations of the radiocarpal joint can occur without radial lip fractures, they are much less frequent than Barton’s fracture-dislocations. Carpal dislocations Most carpal dislocations involve the midcarpal joint, which is between the proximal and distal carpal rows. On the lateral view, these injuries show disruption of the nor- mal relationship between lunate and capitate, usually with dorsal displacement of the capitate. These dislocations usually occur around the lunate and are therefore called “perilunate” disloca- tions. The majority of perilunate dislocations are associat- ed with fractures through the scaphoid waist but any frac- ture within the zone of vulnerability is possible. The description of the injury includes the fractures and the words “perilunate dislocation”. The zone of vulnerability location would be one of these dislocations with fractures through the radial styloid, scaphoid waist and capitate ographs taken on the day of injury. Ulnar styloid fractures are frequently present but are after 2 weeks, will often show these occult fractures. The most common va- dislocated from the lunate and the lunate is subluxed from riety of distal radial fracture is one in which the distal frac- the radius. This term is confusing, since all of these pat- ture fragment is displaced and angulated in a dorsal direc- terns are dislocations of the midcarpal joint. This fracture was first described by Abraham Colles, Other, less-common, carpal dislocations include the in 1814, and now bears his name. These are the result of high-energy this fracture 81 years before the discovery of X-rays, he did trauma and separate the carpus into medial and lateral not know the detail or radiographic manifestations of this portions. His real contribution was to point out that these are frequently require surgical repair. He showed that they could be re- duced and splinted and could heal with excellent results. Carpometacarpal dislocations When the deformity is in the opposite direction (palmar) we refer to the injury as a Smith’s fracture. When there is no Perhaps the most commonly missed serious injury to the deformity, the injury should be described simply as a hand and wrist is dislocation along the carpometacarpal nondisplaced, distal, radial fracture. These injuries can be surprisingly subtle on initial ra- styloid commonly occur in association with distal radial diographs. In spite of this, they are serious injuries that usu- fractures but are not always present.