By N. Armon. Rensselaer Polytechnic Institute.
A 30-year-old African-American woman presents to your office with a chief complaint of weakness albenza 400mg visa. She states that she has been feeling “run down” for several weeks now order 400 mg albenza otc. Further questioning reveals that she is diffusely weak proven 400mg albenza. She has experienced dyspnea on exertion discount albenza 400mg, and she has a new rash. Physical examination is notable for mild tachycardia, pale conjunctiva, petechiae on her mucus membranes and lower extremities, and an absence of hepatomegaly or splenomegaly. Results of a complete blood cell count (CBC) are as follows: hematocrit, 21%; white blood cell count (WBC), 1,200 cells/mm3; and platelet count, 12,000 cells/mm3. The results of a bone marrow biopsy with aspirate are consistent with aplastic anemia. Which of the following statements regarding aplastic anemia is false? Aplasia can be a prodrome to hairy-cell leukemia, acute lymphoblastic leukemia, or acute myeloblastic leukemia B. Viral infections remain one of the major causes of aplastic anemia C. Ionizing irradiation and chemotherapeutic drugs that can be used to treat malignant or immunologic disorders can cause aplastic anemia D. Approximately 20% of patients with hepatitis can experience aplastic anemia 2 to 3 weeks after they experience a typical case of acute hepatitis Key Concept/Objective: To understand the etiologies of aplastic anemia 6 BOARD REVIEW Pancytopenia (i. Aplastic anemia has a number of causes, although in many cases the exact cause cannot be determined. Ionizing irradiation and chemotherapeutic drugs used in the management of malignant and immunologic disorders have the capacity to destroy hematopoietic stem cells. With care- ful dosing and scheduling, recovery is expected. Certain drugs, such as chloramphenicol, produce marrow aplasia that is not dose dependent. Gold therapy and the inhalation of organic solvent vapors (e. In 2% to 10% of hepatitis patients, severe aplasia occurs 2 to 3 months after a seemingly typical case of acute disease. Often, the hepatitis has no obvious cause, and tests for hepatitis A, B, and C are negative. Aplasia can also be part of a prodrome to hairy-cell leukemia, acute lym- phoblastic leukemia, or, in rare cases, acute myeloid leukemia, or it can develop in the course of myelodysplasia. Parvovirus infection is the cause of the transient aplastic crises that occur in patients who have severe hemolytic disorders. The marrow in patients with such disorders must compensate for the peripheral hemolysis by increasing its production up to sevenfold. Although parvovirus can affect all precursor cells, the red cell precursors are the most profoundly affected. Anemia causes fatigue and shortness of breath; throm- bocytopenia causes petechiae, oral blood blisters, gingival bleeding, and hematuria, depending on the level of the platelet count. By far the major problem is the recurrent bac- terial infections caused by the profound neutropenia. The diagnosis of aplastic anemia requires a marrow aspirate and biopsy, as well as a thorough history of drug exposures, infections, and especially symptoms suggesting viral illnesses and serologic test results for hepatitis, infectious mononucleosis, HIV, and parvovirus. Measurement of red cell CD59 is helpful in the diagnosis of paroxysmal nocturnal hemoglobinuria. A 43-year-old white man presents to your clinic complaining of fatigue and paresthesias.
On the other the International Patellofemoral Study Group (IPSG) buy albenza 400mg lowest price,42 there are several explanations: (1) The hand cheap 400mg albenza free shipping, our knowledge of the causative mecha- nisms of anterior knee pain is limited albenza 400 mg discount, with the biomechanics of the patellofemoral joint is more consequence that its treatment is one of the complex than that of other structures in the most complex among the different pathologies knee order albenza 400mg visa; (2) the pathology of the patella arouses of the knee. As occurs with any pathological less clinical interest than that of the menisci or condition, and this is not an exception, for the the cruciate ligaments; (3) there are various correct application of conservative as well as causes for anterior knee pain; (4) there is often operative therapy, it is essential to have a thor- no correlation between symptoms, physical ough understanding of the pathogenesis of the findings, and radiological findings; (5) there are same (see Chapters 2, 3, 4, 8, and 11). This is the discrepancies regarding what is regarded as only way to prevent the all-too-frequent stories “normal;” and (6) there is widespread termino- of multiple failed surgeries and demoralized logical confusion (“the Tower of Babel”). As patients, a fact that is relatively common for the regards what is considered “normal” or “abnor- clinical entity under scrutiny in this book as mal” it is interesting to mention the work by Johnson and colleagues,45 who makes a gender- compared with other pathological processes affecting the knee (see Chapters 20 and 21). We discuss some of the conclusions of this interesting study below. In 1995, the prevailing confusion led to the b In the general population, an estimated one in 3000 indi- foundation by John Fulkerson of the United viduals sustains an ACL injury per year in the United States and Jean-Yves Dupont of France of the States,37 corresponding to an overall injury rate of approxi- 32 37 IPSG in order to advance in the knowledge of mately 80,000 to 100,000 injuries annually. The highest incidence is in individuals 15 to 25 years old who participate the patellofemoral joint disorders by intercul- in pivoting sports. The Background: Patellofemoral Malalignment versus Tissue Homeostasis 5 condition is of such high complexity that even described fissuring and degeneration of the patel- within this group there are antagonistic lar articular cartilage of spontaneous origin,7 and approaches and theories often holding dogmatic in 1908 in another paper described similar lesions positions. Moreover, to stimulate research of traumatic origin. The Patellofemoral Koenig who in 1924 used the term “chondroma- Foundation sponsors the “Patellofemoral lacia patellae” for the first time, although accord- Research Excellence Award” to encourage ing to Karlson this term had already been used in outstanding research leading to improved Aleman’s clinic since 1917. Büdinger considered that the expression emphasize the importance to improve preven- “internal derangement of the knee” was a tion and diagnosis in order to reduce the “wastebasket” term. And he was right since the economic and social costs of this pathology expression lacks any etiological, therapeutic, or (see Chapters 6, 8, and 17). In those patients with pain ically been associated with the terms “internal thought to be arising from this joint, 63% had derangement of the knee” and “chondromalacia “chondromalacia patellae” compared with a 45% patellae. They concluded that America about the CT-assisted classification of patients with anterior knee pain do not always patellofemoral pain. The authors of that paper have patellar articular changes, and patellar highlight the lack of knowledge that besets this pathology is often asymptomatic (Figure 1. In this regard it would “Could be – May be – Possibly be. According to the IPSG42 we should use the The expression “internal derangement of the term chondral or cartilage lesion, and rather than knee” was coined in 1784 by British surgeon resorting to grades in a classification, providing a William Hey. Although hyaline cartilage cannot be the 6 Etiopathogenic Bases and Therapeutic Implications irrelevant. In short, chrondromalacia patellae is not synonymous with patellofemoral pain. Thus, the term chondromalacia, is also, using Büdinger’s own words, a wastebasket term as it is lacking in practical utility. In this way, the fol- lowing ominous 1908 comment from Büdinger about “internal derangement of the knee” could be applied to chondromalacia:22 “[It] will simply not disappear from the surgical literature. It is the symbol of our helplessness in regards to a diagnosis and our ignorance of the pathology. Almost one century has elapsed and this term is still used today, at least in Spain, by clinicians, by the staff in charge of codifying the different pathologies for our hospitals’ data- bases, as well as by private health insurers’ lists of covered services. Patellofemoral Malalignment In the 1970s anterior knee pain was related to the presence of patellofemoral malalignment (PFM). The intensity of preoperative pain is not related to the seri- ousness or the extension of the chondromalacia patellae found during surgery. The most serious cases of chondromalacia arise in patients with a recurrent patellar dislocation who feel little or no pain between their dislocation episodes (a). Chondral lesion of the patella with fragmenta- tion and fissuring of the cartilage in a patient with PFM that consulted for anterior knee pain (b). Therefore, a possible indication for very selected cases could be a resurfacing procedure such as mosaicplasty (see Chapter 12) or periostic autologous trans- plants (see Chapter 13). According to the IPSG,42 the term chondro- Figure 1. One of the founding malacia should not be used to describe a clinical fathers of Sports Medicine. In conclusion, this is a diagnosis that c We define PFM as an abnormality of patellar tracking that can be made only with visual inspection and pal- involves lateral displacement or lateral tilt of the patella, or pation by open or arthroscopic means and it is both, in extension, that reduces in flexion.