By J. Farmon. Clearwater Christian College. 2019.
The tendon should be carefully examined for calcifications or tendinopathy that may be contributing to the patient’s shoulder pain cheap nizoral 200mg without a prescription. A healthy supraspinatus tendon should have a uniform thickness in both the longitudinal and transverse views purchase nizoral 200mg without prescription, with a damaged tendon demonstrating focal thinning or thickening (Fig purchase discount nizoral on line. The musculotendinous unit should then be carefully evaluated for tendinopathy, tear, calcification, and rupture (Figs. Doppler evaluation of the tendon may reveal neovascularization which is associated with the reparative process of tendon damage. If calcific tendinitis is present, ultrasound-guided lavage and aspiration technique may be beneficial (Fig. A: Proper coronal ultrasound transducer position for evaluation of the supraspinatus muscle and tendon with the patient in the neutral sitting position. B: Proper ultrasound transducer position for ultrasound evaluation of the supraspinatus tendon with the patient in the modified Crass position. Longitudinal ultrasound image of the supraspinatus tendon demonstrating chronic thickening of the tendon suggestive of ongoing impingement in the right shoulder. Ultrasound view of the supraspinatus tendon demonstrating heterogeneous hypoechoic area consistent with a fissure of the supraspinatus tendon. Longitudinal ultrasound image of the left shoulder demonstrating a partial-thickness tear of the supraspinatus tendon. Transverse ultrasound image demonstrating a small cortical surface tear of the supraspinatus tendon. Longitudinal ultrasound image demonstrating tendinopathy and a large cortical surface tear of the supraspinatus tendon. Transverse ultrasound image demonstrating bursitis as well as an intrasubstance tear of the supraspinatus tendon with the bursal contour preserved. Transverse ultrasound image demonstrating an intrasubstance tear of the supraspinatus tendon with the bursal contour preserved. Longitudinal ultrasound image demonstrating an intrasubstance tear of the bursal aspect of the supraspinatus tendon. Longitudinal ultrasound image demonstrating bursitis as well as an intrasubstance tear of the supraspinatus tendon with disruption of the bursal contour. Longitudinal ultrasound image demonstrating supraspinatus tendon tearing and fraying with retraction of the bursal surface fibers and infiltrate. Transverse ultrasound image demonstrating a large intrasubstance tear of the supraspinatus tendon. Transverse ultrasound image demonstrating a large, complex tear of the supraspinatus tendon. Ultrasound image demonstrating complex tearing of the supraspinatus and deltoid in patient with history of right shoulder trauma. The critical zone is 8 mm proximal to the insertion of the supraspinatus tendon and represents the area of greatest impingement. Longitudinal ultrasound image demonstrating a massive tear of the supraspinatus tendon with only a few tendon fibers still intact. Ultrasound view of complete tear of the supraspinatus musculotendinous unit with no retraction of the supraspinatus tendon. Transverse ultrasound view of an acute stellate-shaped tear of the supraspinatus musculotendinous unit with significant retraction of the right supraspinatus tendon. Longitudinal ultrasound view of an acute tear of the supraspinatus musculotendinous unit with significant retraction of the supraspinatus tendon. Universal precautions should always be observed to protect the operator and strict adherence to sterile technique must be used to avoid infection when performing ultrasound- guided procedures on the rotator cuff. Gentle physical therapy and local heat should be introduced following ultrasound-guided injection of the supraspinatus tendon to reduce pain and improve function. Prevalence and characteristics of asymptomatic tears of the rotator cuff: an ultrasonographic and clinical study. In conjunction with the teres minor muscle, the infraspinatus muscle externally rotates the arm at the shoulder. Like the supraspinatus muscle, the infraspinatus muscle is innervated by the suprascapular nerve which is composed of fibers from the superior trunk of the brachial plexus (Fig. The infraspinatus muscle finds its origin in the infraspinous fossa of the scapula and inserts into the middle facet of the greater tuberosity of the humerus (Fig. It is at this insertion on the greater tuberosity that that infraspinatus tendinitis and tendinopathy most commonly occur. The infraspinatus muscle is innervated by the suprascapular nerve, which is composed of fibers from the superior trunk of the brachial plexus. The relatively poor blood supply limits the ability of these muscles and tendons to heal when traumatized. Over time, muscle tears and tendinopathy develop, further weakening the musculotendinous units and making them susceptible to additional damage. The patient often complains of sleep disturbance and is unable to sleep on the affected shoulder. Patients with infraspinatus tendinitis exhibit pain with lateral rotation of the humerus and on active abduction of the upper extremity. In an effort to decrease pain, patients suffering from infraspinatus tendinitis often splint the inflamed tendon by rotating the scapular anteriorly to remove tension from the inflamed tendon. If untreated, patients suffering from infraspinatus tendinitis may experience difficulty in performing any task that requires initial abduction of the upper extremity, making simple everyday tasks such as brushing ones teeth or eating difficult. Over time, disruption of the musculotendinous unit, muscle atrophy, and calcific tendinitis may result (Figs. C: Also present is the edema along the musculotendinous junction suggestive of a partial tear (solid arrow). The tendon attachment is intact (dashed arrow in C), and no lesion is noted in relationship to the spinoglenoid notch (dashed arrow in B). Professional beach volleyball player seeded in the top 10 during this tournament and former world champion. A: From this posterior view, a very impressive but completely asymptomatic atrophy of the infraspinatus muscle of the right hitting shoulder is visible. The shoulders of professional beach volleyball players: high prevalence of infraspinatus muscle atrophy.
Molecular size: For water-soluble substances like ions Features of Facilitated Diffusion that pass through aqueous channels buy nizoral 200mg online, permeability is It differs from simple diffusion by four special features: inversely proportional to their molecular size purchase 200 mg nizoral with visa. Faster rate of transport ple nizoral 200 mg fast delivery, a cation like Na attracts more water in its hydration + + 2. Charge on the molecule: Since membrane is polarized Carrier-mediated (facilitated) diffusion allows the trans- with its negative interior, cations easily enter from out- port of polar or hydrophilic molecules at a much faster side into the cell and anions in the opposite direction. Temperature: Rate of diffusion is high at higher body Therefore, inspite of saturation point for the transfer, the temperature as temperature facilitates motion of mole- net transport is more than the simple diffusion (Table 6. Distribution of channels in the membrane: the num- Important Note ber of protein channels for the substance in the mem- Partition coefficient: Partition coefficient is the solubility of the brane determines the permeability of the substance substance in oil compared with the solubility in water. Pressure gradient: In addition to the electrochemical diffuse at a much faster rate through the membrane. Dif- Saturation Kinetics fusion is more from high pressure to low pressure, as In simple diffusion, the rate of diffusion is proportional to the pressure causes greater number of molecule to hit the concentration of the substance and there is no satura- the membrane. In facilitated diffusion, the number of carrier proteins available determines the rate of diffusion. When Properties of the Membrane all the available binding sites on the carrier proteins are In addition to the concentration gradient of the substance occupied, the system operates at the maximum capacity. These factors sion is faster in facilitated diffusion compared to simple are governed by Fick’s law of diffusion. The rate of diffu- diffusion, as there is no involvement of carrier protein in sion of a molecule through a membrane is proportional to simple diffusion. Thus, the net diffusion in facilitated type the surface area (A) available for diffusion, and inversely is more than in simple type (see Fig. According to Fick’s law, for a substance whose inside Competitive Inhibition and outside concentrations are respectively Ci and C0 Many substances share same carrier protein for their mmol/l: transport. Also, Na and Ca com- –6 branes is fairly constant at 10 cm, D/T simplifies to the pete for the sodium-calcium cotransporter on the mem- permeability coefficient ‘P’ of the membrane, and brane and excess presence of one inhibits the transport of Flux = –P × A (C – Ci 0) the other. However, it should not be confused with sodium- calcium exchanger and sodium-glucose cotransporter. It should not be confused with sodium-calcium exchanger that promotes the transport of both ions, When diffusion is facilitated by a carrier protein in the in which increased concentration of one on one side membrane, the process is called facilitated diffusion. This of the membrane increases the transport of the other is also called carrier-mediated diffusion as a carrier pro- from opposite side of the membrane. Also, this should not be confused with carrier-mediated is the transport of various sugars into red cells, adipose transport mechanisms by co-transporters like sodium- tissue, skeletal and cardiac muscles. Like simple diffusion, glucose cotransporter that are essentially facilitatory facilitated diffusion is also a downhill transport that does for transport of more than one substance (Application not require energy. However, specificity is not the solutions are separated by a semipermeable membrane. Facilitated diffusion occurs through ion and, therefore, exhibit random movement (called thermo- channels as occurs in sodium-glucose cotransport, in dynamic activity of water). They pass through a semipermeable membrane, and their passage is proportional to the solvent molecules Factors Affecting Facilitated Diffusion on that side. If the membrane that separates two solutions of dif- tated diffusion as described above. However, the major ferent solute concentrations is semipermeable, which allows the passage of solvent and not the solute parti- cles, the solution with higher concentration solute will Table 6. Mode of diffusion No carrier molecule Carrier molecule tion with a higher thermodynamic water activity to the Involved involved solution with lower thermodynamic water activity, i. Thus, the net flux of water (or solvent) through a semi- reached permeable membrane from a solution of lower solute 3. Competitive Absent Substances that share concentration to that of higher solute concentration is inhibition the same carrier known as osmosis. Specificity No specificity Carrier protein may be A substance to maintain a stable osmotic pressure should specific be confined to one side of the membrane. Solvent movement from ‘b’ to ‘a’ is prevented by application of osmotic pressure on ‘a’. A better example of osmotically most effective sub- Osmole and Milliosmole stance is plasma protein as it is neither transferred from the concentration of osmotically active particles is usu- nor metabolized in the compartment. If a solute is a non-ionizing compound like glucose, Normal saline is effective in hypovolemia: the application of osmotic one osmole is equal to 1 mole of solute particle. A 1 molar solution of glucose has a concentration of solution used to restore circulating blood volume should be the one whose active osmotic constituent remains within the circulation for a 1 Osm (1 osmole per liter). If the solute is an ionizing compound like NaCl, each with plasma, it is usually not used to treat hypovolemia as it is rapidly ion is an osmotically active particle. When the membrane is impermeable to an osmoti- Osmolality and Osmolarity cally active solute, osmotic flow of water ensues and con- tinues into the side containing the solute until either the Osmolality of a solution refers to the number of osmoles membrane bursts (osmotic lysis of cells), or some hydro- (number of osmotically active particles) dissolved in a static pressure prevents further osmotic flow. Osmolarity refers to the number of static pressure necessary to prevent osmotic flow of water osmoles in one liter of plasma. Unlike osmolality, the value in osmolarity is affected by Osmotic pressure depends on the number of mole- the volume of other solutes in the solution. In case of nondissociated solutes, 1 gm mol wt of any the difference between osmolality and osmolarity is substance shall contain similar number of molecules negligible. Osmoles determine osmotic pressure: Note that the important factor Osmotic pressure in body fluid is mainly exerted by determining the osmotic pressure of a solution is the concentration of osmotically active solutes dissolved in the fluid such as the particles released in solution (i. The osmotic pressure due to presence of plasma proteins is called oncotic pressure. Oncotic pressure significantly contributes very little, even though their molecules are large in size. Therefore, edema occurs in the normal plasma osmolality is 290 mOsm per kg, out of hypoproteinemia. Chapter 6: Transport Across the Cell Membrane 49 Measurement of Osmotic Pressure Measuring Equivalent Hydrostatic Pressure By Freezing Point Depression In experimental set up, osmotic pressure can be measured Osmometers are used to measure osmotic pressure. The by measuring the hydrostatic pressure applied to prevent molar concentration of a solute in a solution determines water from entering the solution with higher solute con- the osmotic pressure, and also the vapor pressure and centration. One mol Filtration, Bulk Flow and Solvent Drag per liter depresses the freezing point of water by 1.
The abnormal white matter tracts associated the genesis of epileptic activity [63 order nizoral 200 mg on line,64 buy nizoral 200mg with mastercard,65 cheap 200 mg nizoral with visa,66,67,68]. Normal brain cells consume glucose as the children and should not lead to exclusion from presurgical eval- major source of energy, and hypometabolic areas are ofen associat- uation. Widdess-Walsh , in a series of 48 patients, showed that ed with epileptogenic foci. We will discuss the benefts and limitations of to correlate better with the epileptogenic zone than glucose hypo- each method. This pattern was present in 67% of aging is primarily used to measure regional cerebral blood fow patients and correlated well with the anatomical extent of the lesion. By comparing of Palmini was also noted in 12% of patients with glioneural tu- the ictal scan and the interictal scan (which serves as a reference mours. Tese studies and techniques appears to be a highly sensitive method in the presurgical others demonstrate that, when present, epileptiform discharges can evaluation of a patient with cortical dysplasias. The yield depends delineate the extent of the epileptogenic zone and provide the sur- on early administration of the radiotracer at the onset of the seizure, geon with an excellent tool in determining the extent of resection. However, there have developed a specifc expertise in its administration and data has not been a randomized trial to directly document the efcacy of analysis. Tese both allow mapping of cortical function, there- Electrode recordings from nodular heterotopias have shown fore correlating ictal discharges with adjacent cortical function. The independent epileptiform discharges occurring in the heterotopia choice of electrodes is infuenced by the centre preference and the and the overlying cortex. At times, a combination of subdural ity can come from heterotopia, the overlying cortex and/or mesial and depth electrodes is indicated. In this pathology, the ictal onset zone is frequently out- zone led to a 65% seizure-free outcome. Incomplete resection of side the polymicrogyric cortex and involves the mesial temporal the ictal onset zone was associated with an 8% seizure-free out- structures. In this case, surface or subdural ization of the central sulcus is possible with an accuracy of a few electrodes are inadequate to localize epileptogenic zone because millimetres . In addition, various language paradigms allow of its inaccessibility to the deep-seated lesions or the intrasulcal mapping of speech areas [96,98,99,100]. Heterotopia of grey matter is classifed into three types: laminar, Depth electrode investigations are also particularly informative band and nodular. Nodular heterotopia is further classifed accord- in periventricular nodular heterotopias, and several authors con- ing to the location: periventricular or subcortical. Epilepto- be focal or multifocal, and it may or may not be associated with genicity in these lesions involves a complex network that includes other cortical malformations. Identifying a focal generator is a good er cortical malformations had a more benign clinical course. Occasionally, if the heteroto- thickness of the cortex lined by polymicrogyria; therefore, it is of- pia is unilateral and localized, and its epileptogenicity confrmed ten included in the same category of cortical organization disor- (usually by invasive monitoring), seizure-free outcome may be ob- der as polymicrogyria . One of the difculties associated with tained afer surgery (9 out of 16 patients from refs  and  these cases comes from the fact that the cortex within the clef is combined). In these cases, resection of additional areas adjacent to not easily accessible for recording. Surgical techniques used in case the heterotopic nodules and/or other remote epileptogenic area was reports include partial or total resection of the walls of schizence- almost always necessary. Continuing with the theme of prenatal and perinatal insult, por- Tese patients had a higher prevalence of epilepsy, developmental encephaly is sometimes associated with epilepsy. When they did undergo present with hemiparesis and intellectual impairment in addition to resection, whether it was directed at the heterotopia or the mesial intractable epilepsy . Hemispherectomy of various degrees is temporal sclerosis, the result was generally poor . Depending on cerebral cortex and therefore afords the possibility of surgical re- the extent of involvement, agyria and pachygyria are also included section as a treatment option. A PubMed search did not identify surgical series greater availability of surgical specimens enables histological, mo- based solely on patients with lissencephaly. In case series on corpus lecular and genetic studies, which then make possible correlations callosotomy, some patients, whose underlying abnormality were with clinical and imaging fndings. Surgical technique included anatomical with dysmorphic neurons in the setting of architectural abnormal- hemispherectomy or hemicorticectomy or functional techniques ities . Patients can present with generalized or partial sei- zure or in status epilepticus. Even although some show transient Surgical outcome in polymicrogyria and schizencephaly responsiveness to antiepileptic drug therapy, this group of patients Polymicrogyria consists of abnormally small gyri that could be ofen has intractable seizures . Histologically, there is a de- presence of dysmorphic and balloon cells was positively correlated creased number of neurons, which is most pronounced at layer V. However, the correlation proliferation and migration of the neurons are grossly intact, and between histology and surgical outcome is much less well defned it is the late process of cortical organization that is interrupted . Tus, it is generally believed that polymicrogyria is an acquired le- sion due to intrauterine insults, which is mimicked by the rat freeze Neuroimaging lesion model. Tere are few case reports of surgical treatment of Approximately 90% of patients who were selected for surgery and polymicrogyria and no surgical series were identifed [113,114,115]. Because a signifcant proportion presence of balloon cells predicts surgical outcome. Conficting re- of patients who underwent complete resection per imaging criteria sults were found in these surgical series. Although some found that still sufer from seizures (see Section Surgical outcome of focal cor- the presence of balloon cells was correlated with better outcome tical dysplasia), the answer is probably ‘no’. As a whole, data from a pool of 210 patients will be ofered surgery and better outcome will be obtained, but indicate that the presence of balloon cells is not a reliable prognos- there will always be a small number of patients whose lesions escape ticator of seizure-free surgical outcome. The focal nature of the disease means bar localization were positive predictors of long-term seizure-free that patients are more ofen selected for surgery than those with outcome . We have reviewed surgical series based indicator of seizure-free outcome afer epilepsy surgery is whether on patients who underwent resective surgery and whose histolog- the entire lesion was removed or not [145,146,147,148]. It is reported that, on average, 80% of pa- were published since 2000 and all had a follow-up period of at least tients are seizure free afer complete resective surgery relative to 1 year. Studies were included only if seizure-free outcome was reported resections [149,150,151].
J chain Mucosal Proteolytic cleavage epithelial cell site Secretory antibodies are secreted antibodies that possess a tail piece buy nizoral 200 mg overnight delivery, J chain effective 200mg nizoral, and secretory component subjected to Figure 15 generic 200mg nizoral free shipping. The initial IgM response is followed later surface area to the opposite cell surface through intracellular by IgA with conversion to IgG 22 to 33 days after infection. IgG produced locally is rapidly scytosis across intestinal epithelial cells in vesicles that are inactivated when it reaches the gastric juice. A systemic IgG formed on the basolateral surface and fuse with the apical response is present throughout the infection and diminishes, surface in contact with the intestinal lumen. There is great variability in the Apical is an adjective describing that surface of an epithelial specifcity of circulating host antibody against H. This is attributable in part to variations in host response and to a lesser degree to antigenic diversity of the microorgan- Antiseptic paint is a colloquial designation for the coating isms, such as variation in the Vac A and Cag A proteins. Most effect of secretory IgA, such as that produced locally in the infected subjects synthesize antibodies against numerous gut, on mucosal surfaces, thereby barring antigen access. Antibodies usually develop to Vac Secretory component (T piece) or secretory piece is A and Cag A polypeptides if they are present in the infect- a 75-kDa molecule synthesized by epithelial cells in the ing strain. Although of variable complexity, the antigens all lamina propria of the gut that becomes associated with IgA include urease. Plasma cells, lymphocytes, and monocytes molecules produced by plasma cells in the lamina propria infltrate the superfcial layers of the lamina propria in H. Half of the mature B cells and infl- cell layer to reach the mucosal surface of intestine to provide trate are B cells that are producing mostly IgA but also IgG local immunity. It is also called secretory component and gastric epithelium, which induces neutrophil chemotaxis. Of is a fragment of the poly-Ig receptor that remains bound to the non-Hodgkins lymphoma cases affecting the stomach, Ig following transcytosis across the epithelium and cleav- 92% are associated with H. It is not formed by plasma cells in the lamina propria engage an immune avoidance by continually losing highly of the gut that synthesize the IgA molecules with which it antigenic material such as urease and fagella sheath from combines. Secretory component has a special affnity for the bacterial surface thereby diminishing the effectiveness of mucous, thereby facilitating IgA’s attachment to the mucous bound antibodies. An oral subunit vaccine used with a mucosal adjuvant the sacculus rotundus describes the lymphoid tissue-rich has protected animal models. The disorder is very infrequent but is char- cells in the center of nodules stain lighter than do those at the acterized by the protracted diarrhea associated with gut periphery. This tissue plays an important role in IgG1, and IgG4, and often IgG2 antibodies are detectable mounting an immune response to inhaled antigens in respira- but IgG3 and IgM antibodies only rarely. Mucosal Immunity 501 Oral feeding of a protein antigen may lead to profound systemic immunosuppression involving both the B cell (antibody-mediated) and T cell (cell-mediated) limbs of the Alveolar wall immune response to that specifc antigen (Figure 15. T cell clonal anergy is induced to some protein antigens administered by this route. Yet, possible nonprofessional antigen-pre- senting cells involved in the induction of oral tolerance have not been identifed. Specifc local immunity may be attributable to activation or infec- Oral immunology: Saliva not only rinses the oral cavity but tion of antigen-presenting cells in the intestinal epithelium. Feeding of autoantigen to induce oral leukocytes are important in protection of gingival tissues and tolerance has potential therapeutic value for the treatment of ultimately the periodontium. Antigen may also reach nodefciencies often have increased mucosal infections by Peyer’s patches through M cells and led to a T and B cell opportunistic microorganisms, such as by Canda albicans. Oral or intranasal bouts of vaccine administration the epithelial layer is not only a mechanical barrier against may prove useful to protect against oral infections. This Oral unresponsiveness is the mucosal immune system’s class of immunoglobulin is also responsible for the passive selective ability to not react immunologically against anti- transfer of immunity from mother to young through the milk gens of food and intestinal microorganisms even though it and colostrum. Most of the antibodies produced in the nor- responds vigorously to pathogenic microorganisms. Antibody affnity maturation occurs in germinal immune protection of the newborn prior to maturation of its centers of Peyer’s patches where stimulated B lymphocytes own immune competence. IgA-synthesizing B lympho- cytes populate the lamina propria or other mucosal tissues. Coproantibody is a gastrointestinal tract antibody, com- monly of the IgA class, which is present in the intestinal the relatively large quantity of secretory IgA synthesized in lumen or feces. IgA-producing B lymphocytes in immunological unresponsiveness to skin-sensitizing chemi- other parts of the body are responsible for serum IgA. Oral tolerance is antigen-induced specifc suppression of Intravenous administration of the chemical may also block humoral and cell-mediated immunity to an antigen follow- the development of delayed-type hypersensitivity when the ing oral administration of that antigen as a consequence of same chemical is later applied to the skin. Simple chemicals anergy of antigen-specifc T lymphocytes for the formation of such as picryl chloride may induce contact hypersensitivity immunosuppressive cytokines such as transforming growth when applied to the skin of guinea pigs. Oral tolerance may inhibit immune responses ness may be abrogated by adoptive immunization of a tol- against food antigens and bacteria in the intestine. Proteins erant guinea pig with lymphocytes from one that has been passing through the gastrointestinal tract induce antigen- sensitized by application of the chemical to the skin without specifc hyporesponsiveness. Based on sue that contains diffuse epidermal T cells, including αβ and the quantity of antigen fed, orally administered antigen may γδ T cells and dendritic cells (Langerhans cells) together with induce regulatory cells that suppress the antigen-specifc dermal αβ T cells, fbroblasts, dendritic cells, macrophages, response (low doses) or inhibit antigen-specifc T cells by and lymphatic vessels. These cells migrate from the gut to organs that contain the fed antigen, Skin immunity: the skin, the largest organ in the body, where the Th2 cells are stimulated locally to release antiin- shields the body’s interior environment from a hostile exterior fammatory cytokines. The skin defends the host through stimulation of infammatory and local immune responses. Antigen applied Mucosal tolerance is the hypothesis that continuous expo- to or injected into the skin drains to the regional lymph nodes sure of an individual to a modest quantity of a specifc anti- through the skin’s extensive lymphatic network. Cells of both gen through a mucosal route renders tolerance to that antigen systemically. As a consequence, there is abrogation of the immune response to that same antigen administered later by a non-mucosal route. Epidermis Lagerhans Maternal immunity describes passive immunity conferred cell on the neonate by its mother. This is accomplished prepar- T cell tum by active immunoglobulin transport across the placenta from the maternal to the fetal circulation in primate animals Fibroblast including humans. Other species such as ungulates transfer Lymphatic Dermis immunity from mother to young by antibodies in the colos- vessel trum since the intestine can pass immunoglobulin molecules Macrophage Mast cell across its surface in the early neonatal period. Mucosal Immunity 503 the epidermis, papillary, and reticular dermis have critical the activated T cells.
The second metacarpal articulates primarily with the trapezoid and secondarily with the trapezium and capitate (Fig discount nizoral 200 mg with amex. The third metacarpal articulates primarily with the capitate purchase 200mg nizoral overnight delivery, with the fourth metacarpal articulating with the capitate and hamate purchase nizoral online from canada. The carpometacarpal joints of the fingers are shaped differently than the first carpometacarpal joint in that the curvature of the distal articular surface of the base of the metacarpal is more dome shaped making for a more stable joint as it articulates with its corresponding carpal bones (Fig. Each joint is lined with synovium and the ample synovial space allows for intra-articular placement of needles for injection and aspiration. Compared to the first carpometacarpal joint, the carpometacarpal joints of the fingers have a denser and tighter joint capsule and stronger transverse and interosseous ligaments. These differences combined with a much more limited range of motion when compared with the range of motion of the first carpometacarpal joint all contribute to greater joint stability, although fracture and subluxation still occur. The carpometacarpal joints of the fingers are also susceptible to overuse and misuse with resultant inflammation and arthritis. Differences between the first metacarpal joint and the carpometacarpal joints of the fingers. The articular cartilage of the carpometacarpal joints of the fingers are susceptible to damage, which left untreated, will result in arthritis with its associated pain and functional disability. Osteoarthritis is the most common form of arthritis that is seen in the carpometacarpal joints of the fingers which results in pain and functional disability, with rheumatoid arthritis, posttraumatic arthritis, and crystal arthropathy also causing arthritis of the carpometacarpal joints of the fingers (Fig. Less common causes of arthritis-induced pain of the carpometacarpal joints of the fingers include the collagen vascular diseases, infection, villonodular synovitis, and Lyme disease. Acute infectious arthritis of the carpometacarpal joints of the finger joint is best treated with early diagnosis, with culture and sensitivity of the synovial fluid and prompt initiation of antibiotic therapy. The collagen vascular diseases generally manifest as a polyarthropathy rather than a monoarthropathy limited to the carpometacarpal joints of the fingers, although pain of the carpometacarpal joints of the fingers secondary to the collagen vascular diseases responds exceedingly well to ultrasound-guided intra-articular injection. Activity, including pinching and grasping motions, makes the pain worse, with rest and heat providing some relief. Sleep disturbance is common with awakening when patients roll over onto the affected wrist and hand. Some patients complain of a grating, catching, or popping sensation with range of motion of the joints, and crepitus may be appreciated on physical examination. Functional disability often accompanies the pain associated with many pathologic conditions of the carpometacarpal joints of the fingers joint. Patients will often notice increasing difficulty in performing their activities of daily living and tasks that require grasping or pinching objects such as writing with a pen or pencil, opening a jar, or picking up a ball. If the pathologic process responsible for pain of carpometacarpal joints of the fingers is not adequately treated, the patient’s functional disability may worsen and muscle wasting and ultimately a frozen carpometacarpal joints of the fingers joint may occur. Plain radiographs are indicated in all patients who present with pain of the carpometacarpal joints of the fingers (Figs. Based on the patient’s clinical presentation, additional testing may be indicated, including complete blood cell count, sedimentation rate, and antinuclear antibody testing. A small linear high-frequency ultrasound transducer is placed in a longitudinal parallel axis over the base of the metacarpal to be injected and a survey scan is taken (Fig. The transducer is slowly moved proximally along the metacarpal until the hypoechoic cleft between the base of the metacarpal and the distal articular surface of the carpal is in the center of the image. After the joint is identified, it is evaluated for arthritis, effusion, synovitis, infection, ganglion cysts, tumor, and crystal arthropathy (Fig. The overlying tendons and surrounding soft tissue is then evaluated for abnormality (Figs. Correct patient position for ultrasound evaluation of the carpometacarpal joints of the fingers joint. Longitudinal ultrasound image demonstrating erosive changes of the second carpometacarpal joint in a patient with rheumatoid arthritis. Extended field of view image demonstrating a low echogenicity mass (arrows) adjacent to the flexor tendon. Longitudinal ultrasound image demonstrating a ganglion of the abductor pollicis longus. Care should be taken to correctly diagnose all pathology responsible for the patient’s pain and functional disability so a rational treatment plan can be designed and implemented. Degenerative and post-traumatic arthritis affecting the carpometacarpal joints of the fingers. The ligament and skeletal anatomy of the second through fifth carpometacarpal joints and adjacent structures. Technique for intra-articular injection of the carpometacarpal joint of the fingers. Anatomy and pathomechanics of ring and small finger carpometacarpal joint injuries. The most common site of pathology in trigger finger is in the flexor tendon and tendon sheath of the flexor digitorum superficialis and profundus muscles of the second to fifth fingers. Sesamoid bones, bone excrescences, and foreign bodies within the tendon sheath at the level of the metacarpal heads may also contribute to the development of trigger finger (Fig. The key landmark when performing ultrasound-guided injection for trigger finger is the A1 pulley at the level of the metacarpophalangeal joint. Sagittal sonogram shows the volar plate at the level of joint space (arrows), with the flexor tendon more superficial (T). Sonography of the finger flexor and extensor system at the hand and wrist level: findings in volunteers and anatomical correlation in cadavers. A nerve tract ran on the radial aspect of the tumor, causing compression (arrowhead). Locked metacarpophalangeal joint of the middle finger caused by a lipoma in the flexor tenosynovium: a case report. Other causes of trigger finger include direct trauma to the tendon sheaths, especially at the site of the A1 pulley, tendon sheath infection, nodules, foreign body, or compression by osteophytes of the heads of the metacarpal, sesamoid bones, or abnormal bone growth from other medical conditions such as acromegaly (Fig. Repeated irritation from repetitive motion as the tendons pass back and forth over boney prominences and through swollen and stenotic tendon sheaths can cause significant tendinopathy and edema of the tendon sheaths themselves (Fig. Over time, if the inflammation remains untreated, nodules may develop of the tendons which may lock as they pass beneath a retraining tendon pulley causing a triggering phenomenon as the nodule catches on the pulley. When this occurs, the patient experiences a catching or locking of the finger when the finger is in flexion or extension (Fig. Activities associated with the development of trigger finger included repetitive gripping activities involving the hand such as clenching a horse’s reins or steering wheel too tightly.
Hemostasis occurs in two major steps: temporary hemostasis and defini- Thrombocytopenia is defined as the platelet count less 3 tive hemostasis nizoral 200 mg low price. There- 3 in prevention of bleeding purchase 200mg nizoral amex, which is called temporary fore order 200mg nizoral mastercard, platelet count below 50,000/mm of blood is hemostasis. Therefore, splenectomy usually causes thrombocy- Role in Temporary Hemostasis tosis and hypersplenism invariably causes thrombo- cytopenia. Immediate hemostasis following vascular injury is achieved by formation of platelet plug (also called, plate- Thrombocytosis let thrombus) at the site of injury. As platelet thrombus Thrombocytosis commonly occurs in polycythemia vera, can be washed away, unless supported by a clot, this is chronic myeloid leukemia, iron deficiency anemia, sple- called temporary hemostatic plug. Temporary hemostatic nectomy, chronic infection, surgery, and following acute plug formation depends on adhesion, platelet aggrega- hemorrhage. Hematocrit: Increased number of red cells increases platelet aggregation by forcing the platelets to the periphery of the blood stream. This is because red cells disproportionately occupy the axial region of the blood in the blood vessels pushing the leucocytes and thrombocytes to the vessel wall. Speed of blood flow: When blood flow is faster, plate- lets do not get adequate time to interact with vessel wall. Also, the force tending to pull platelet from ves- sel wall and from another platelet is more in fast flow that prevents platelet adhesion and aggregation. Size of blood vessel: This determines the number of platelets passing through the vessel at a given time that influences platelet adhesion to vessel wall. B Platelet Aggregation Platelet adhesion is immediately followed by platelet aggregation at the site of injury (Fig. Simultaneously, platelets are activated, and activated platelets release chemicals from their granules (refer Fig. Note, exposed collagen of the site of vascular injury facilitates the process of tempo- damaged vascular endothelium promote adhesion; (B) Platelet aggregation; (C) Formation of fibrin threads in and around the rary hemostatic plug (platelet thrombus) formation. However, platelet adhesion is also controlled by following factors: Important Note 1. Depth and degree of injury: Deeper and extensive the Use of antiplatelet drugs such as aspirin: Aspirin inhibits platelet aggregation by inhibiting the membrane enzyme cyclooxygenase injury more is the platelet aggregation. Cyclooxygenase facilitates thromboxane A2 formation to release of more quantity of platelet activating fac- that facilitates platelet aggregation and causes vasoconstriction. Site of injury: Injury in mucocutaneous vascular bed of myocardial infarction and stroke. Platelet aggregation is Adhesion of platelets to damaged vascular endothelium more in mucocutaneous tissue. Age of the individual: As composition of vessel wall occurs in activated platelets that results in pseudopodia or changes with age, platelet aggregation alters with age spicules formation. In elderly individuals, the aggrega- tors and chemicals released from granules of the platelets, tion is less. Inhibitors of thrombin generation and action • Arachidonic acid is converted to endoperoxides by cyclooxygenase. Following are the possible mechanisms of • Serotonin released from platelet produces vasocon- platelet release. Through Platelet Activating Factor Through Thrombospondin and Thrombonectin Platelet adhesion activates platelets. Note the factors produced by endothelial cells that promote and inhibit hemostasis. They also facilitate the conversion of X to Xa and pro- Role of Vascular Wall in Hemostasis thrombin to thrombin (Flowchart 20. Thus, platelets Vascular endothelium plays an important role in hemo- accelerate thrombin formation. Endothelial cells of blood vessel synthesize certain substances that are inhibitory and substances that have Role in Clot Retraction facilitatory influence on hemostasis (Fig. If platelets are present in the clot in a test tube, within minutes to hours, the clot contracts, extruding a very large Inhibitors of Hemostasis fraction of serum. The platelet filopodia extends into fibrin clot and fibrin inhibitory influence on hemostasis. Thus, shrinkage of platelet • Thrombomodulin with contraction of filopodia causes internalization of • Protein S fibrin that causes clot retraction. Role in Thrombolysis Heparin: Heparin-like substances on the surface of Role of platelet in fibrinolysis is complex. Endothelial cells also synthesize tis- brinolytic are synthesized and released by platelets. However, antifibrinolytics like plasminogen activator plasmin, and activates fibrinolytic system. Platelets by causing clot retraction decrease the effi- Certain factors synthesized by endothelial cells promote ciency of thrombolysis. It appears that antifibrinolytic effects of platelets pre- and platelet activating factor. Tissue factor or thromboplastin activates extrinsic sys- platelet rich thrombus is known to resist thrombolysis. Platelet activating factor induces aggregation of plate- by estimating the platelet retention in the tube. Another vascular factor promoting hemostasis is vaso- anticoagulant, clotted blood retracts and 50% retrac- constriction of small vessels following injury. Subendothelial collagen promotes platelet adhesion completes at the end of 18 to 24 hours. Platelet count: Decreased platelet count is associated with prolongation of bleeding time. Platelet count is not routinely ordered in which usually occurs due to formation of antibody against clinical practice. Antiplatelet antibodies get attached to platelet hemostatic mechanisms, especially in the diagnosis of membrane glycoproteins, and these platelets are phagocy- a bleeding disorder, platelet count is a must. It is prolonged in severe and occurs equally in both genders that usually thrombocytopenia and thrombasthenia. Thecommon featureof the disease isbleedingthat usu- gate is assessed with the help of aggregometer.
Ultrasound (A) and axial fluid sensitive magnetic resonance (B) images show heterogeneous mass (arrows) originating from and surrounding the femur (F) (pathologically proven) purchase nizoral mastercard. It should also be noted that traction apophysitis of the inferior patella which is known as Sinding-Larsen–Johansson disease can easily be confused for Osgood– Schlatter disease (Fig purchase cheap nizoral on line. A: Lateral radiograph of the right knee shows fragmentation of the lower pole of the patella and significant soft-tissue swelling associated with calcifications and ossifications of the patellar ligament—findings characteristic of Sinding-Larsen–Johansson disease cheap nizoral 200 mg with visa. Longitudinal image of the patella apex and patella tendon origin in Sinding-Larsen–Johansson disease. The adjacent patellar tendon is thickened and hypoechoic in keeping with tendinosis. Osgood-Schlatter disease: a new perspective and classification based on ultrasonography. Elongated patellae at the final stage of Osgood-Schlatter disease: a radiographic study. The saphenous nerve provides sensory innervation to the medial malleolus, the medial calf, and a portion of the medial arch of the foot (Fig. The saphenous nerve is derived primarily from the fibers of the L3 and L4 nerve roots. The nerve travels along with the femoral artery through Hunter’s canal and moves superficially as it approaches the knee (Fig. It passes over the medial condyle of the femur, splitting into terminal sensory branches. The infrapatellar branch of the saphenous nerve provides sensory innervation to the area below the patella. The saphenous nerve is subject to trauma or compression anywhere along its course. The nerve is frequently traumatized during vein harvest for coronary artery bypass grafting procedures. The saphenous nerve is also subject to compression as it passes over the medial condyle of the femur. Less commonly, saphenous neuralgia can occur as an isolated mononeuropathy without apparent cause. The infrapatellar branch of the saphenous nerve is frequently damaged during total knee arthroplasty and results in numbness and dysesthetic pain in the infrapatellar region (Fig. The symptoms associated with saphenous neuralgia depend on the point at which the nerve is damaged (Fig. The symptoms of saphenous neuralgia are constant pain that radiates into the inferomedial aspect of the calf and the area below the patella if the inferior patellar branch of the nerve is affected (Fig. The pain of saphenous neuralgia is exacerbated by activity including walking, climbing stairs, and kneeling. Tenderness over the nerve to palpation as the nerve exits the adductor canal is common. Ultrasound-guided saphenous nerve block with local anesthetic may serve as a diagnostic modality and is useful in the treatment of persistent postoperative neuropathic pain following vein harvesting and stripping procedures. Electromyography can distinguish saphenous nerve dysfunction from lumbar plexopathy, lumbar radiculopathy, and diabetic polyneuropathy. Plain radiographs of the knee and 963 distal lower extremity are indicated in all patients who present with saphenous neuralgia to rule out occult bony pathology (Fig. Based on the patient’s clinical presentation, additional testing may be warranted, including a complete blood count, uric acid level, erythrocyte sedimentation rate, and antinuclear antibody testing. Magnetic resonance imaging of the point of suspected nerve compromise is indicated to clarify the diagnosis or if tumor, infection, or hematoma is suspected (Fig. Ultrasound and computed tomographic scanning are also indicated if mass or tumor is suspected or if the cause of saphenous nerve compromise is in question (Fig. Anteroposterior (A) and lateral (B) radiographs of a patient with osteomyelitis of the femur. Sagittal T2-weighted magnetic resonance image shows a fracture of the medial tibial plateau (small black arrows) associated with a tear of the posterior horn of the medial meniscus (white arrows). Schwannoma of the saphenous nerve (arrows = schwannoma, arrowheads = saphenous nerve, curved arrow = saphenous vein). A point approximately 5 cm above the patella on the anteromedial femur is then identified by palpation. A linear high frequency ultrasound transducer is placed in a transverse plane over the previously identified point on the anteromedial femur and an ultrasound survey scan is obtained (Figs. The hyperechoic anterior medial border of the femur will be visualized as well as the vastus medialis muscle just anteromedial to it (Fig. The ultrasound transducer is then slowly moved in a more medial direction until the sartorius muscle which lies posteromedial to vastus medialis muscle is visualized (Fig. The saphenous nerve lies just in the fascial plane just below the sartorius muscle (Fig. When the fascial plane below the sartorius muscle is identified on ultrasound imaging, the saphenous nerve is followed inferiorly and evaluated for evidence of compression of compromise by bony abnormality or soft tissue mass, neuropathy as evidence of loss of normal sonographic neurofibular architecture, and intraneural tumors (Fig. Proper transverse position of the ultrasound trasnducer for ultrasound evaluation of the saphaneous nerve at the knee. Transverse ultrasound image demonstrating the vastus medialis lying above the anteromedial femur. A comparison of ultrasound-guided and landmark-based approaches to saphenous nerve blockade: a prospective, controlled, blinded, crossover trial. The transversely placed ultrasound transducer is moved medially to identify the sartorius muscle and the saphenous nerve beneath it. A comparison of ultrasound-guided and landmark-based approaches to saphenous nerve blockade: a prospective, controlled, blinded, crossover trial. It should be remembered that isolated injury of the infrapatellar branch of the saphenous nerve will produce sensory deficit limited to the infrapatellar region (Fig. Transverse ultrasound image of the medial quadrant of the leg showing the saphenous nerve and the infrapatellar branch of the saphenous nerve.