This hypothesis might explain why ipsilateral frontal lobe ex- seizure-related) process cheap antabuse 500mg with visa treatment 20 initiative, present in seizure propagation pathways purchase antabuse without a prescription treatment vaginal yeast infection, citability, as measured with transcranial magnetic stimulation, in and which is a defence mechanism against seizure propagation. Ictal surround inhibition has been shown to be present sion, and may be responsible for interictal and ictal functional def- in the cortex surrounding an epileptic focus using optical imaging, cits, which may be reversible upon cessation of seizure activity. In which is a functional imaging modality based on the same principle this hypothesis, some interneurons in the hyperperfused temporal of coupling of focal alterations in metabolism and blood fow . Patient was a 21-year-old woman with a 3-month history of a simple focal status epilepticus of the lef parietal lobe, characterized by continuous paraesthesiae in the right arm. The top row (a) shows the results in the lef parietal region (red crosses) and the bottom row (b) in the lef frontal region (blue crosses). This fgure illustrates the dynamic, seizure-related character of the metabolic changes, and that ictal hypometabolism is mainly present in seizure propagation pathways, and does not defne the ictal onset zone. At the time of scan A, she had severe cognitive defcits, which had normalized at the time of scan B. The hypometabolism in the epileptic temporal lobe, on the other hand, is less striking than the changes in the extratemporal regions. Seizures are the most common symptom of the disease, and executive function, and found that resting frontal lobe metabolic infantile spasms or West syndrome is particularly frequent during values were strong predictors of executive functioning in patients the frst several years of life. Jokeit and colleagues  reported a correlation be- lesions, however, identifying the epileptogenic tuber(s) is difcult. Medical personnel should be white matter, inferior precentral gyrus and anterior cingulate gyrus educated in handling of radioligands, and be familiar with the elec- in the ipsilateral hemisphere, suggesting that hypometabolism in troclinical features of epileptic seizures. The brain perfusion agent these regions was functional, seizure related and reversible. On the should be available in the room, and the injection system should other hand, decreases were seen in brain structures with aferents allow for fast ictal injections [78,79]. In the presurgical assessment, atten- amines rapidly cross the blood–brain barrier (up to 85% of brain tion is focused on eloquent cortex and loss of function afer epilep- uptake on the frst pass). It is equally important to counsel the patients on what philic compound that is trapped within cells, which prevents wash- they could gain in terms of cerebral functioning afer successful out. The activity in the brain remains essentially 782 Chapter 61 constant and proportional to regional perfusion at the time of ad- be known, because early injections give the best results. With early injections, the largest and most intense up to 4 h afer their intravenous administration during a seizure cluster is more likely to represent the seizure onset zone, and not . Several propagation patterns have been de- had to be reconstituted rapidly at the bedside during a seizure , scribed. Noachtar and colleagues reported propagation in 85% ligand, and which allowed for earlier ictal injections. Propagation from one any time, without the requirement of running a complex cyclo- temporal lobe to the contralateral temporal lobe has been reported tron. The kinetic profle of these tracers with fast uptake and sta- in around 1% of cases . Methodologically, lobe seizures with fast seizure propagation and relatively later ictal this can be done by traditional side-by-side visual evaluation, but injection times. Complex focal seizures give the best results, and the interictal image is then subtracted from the ictal. The difer- and secondarily generalized seizures may give multiple regions ence image is smoothed and transformed into a z-score map using of hyperperfusion . Afer injection in an arm of acquisition movement artefacts, registration errors) and subtrac- vein, the tracer takes around 30 s to reach the brain. The injection time should diagnostic evaluation without imaging, while this was only 0. The patient has remained seizure free since the operation with a follow-up of more than 1 year. Combinations of these imaging modalities that integrate studies of complex focal seizures of extratemporal lobe origin also the strengths of modalities and at the same time eliminate one have an excellent localizing value, but may be more difcult to ob- or more weaknesses of an individual modality, may provide new tain when the seizures are brief in duration [100,101]. On the lef side, Broca’s and Wernicke’s area were at a distance from the focal dysplastic lesion. Difusion tensor tractography of the arcuate fasciculus showed that fbres connecting Broca’s and the inferior parietal lobule crossed the focal dysplastic lesion ((f) green tract, white arrow). Although the lesion was outside the classical language areas, that is Broca’s speech and Wernicke’s comprehension centres, and the interconnecting arcuate tract, our imaging data suggested that the lesion was in the indirect pathway of perisylvian language networks . Damage to this region could cause conduction aphasia, necessitating further functional studies preoperatively. High resolution in the presurgical evaluation of patients sufering from refractory partial epilepsy. Surgical outcome and prog- system in temporal lobe epilepsy with hippocampal sclerosis. Temporal lobe hypometabolism on in malformations of cortical development: A quantitative study. The dynamics of value of [18F]-fuoro-D-deoxyglucose positron emission tomography in screening metabolic change following seizures as measured by positron emission tomogra- for temporal lobe epilepsy surgery. Epileptic patterns of local cerebral metab- sion tomography in refractory complex partial seizures. Am J Nucl Med Mol Imaging 2014; 4: epilepsy: a distinct surgically remediable syndrome. In vivo hippocampal glucose metabolism tabolism relates to outcome of temporal lobectomy. When should a resection sparing mesial structures be tion of cortical dysplasia in patients with epilepsy. The added clinical Surgical treatment of intractable neonatal-onset seizures: the role of positron and economic value of diagnostic testing for epilepsy surgery. Diference images calculated from ictal and localization of extratemporal epileptic foci. Optimizing predicts seizures in acutely drug-reduced temporal lobe epilepsy patients. Ictal hyperperfusion patterns according to asymmetric interictal glucose hypometabolism and cognitive impairment in pa- the progression of temporal lobe seizures. Depression in temporal lobe epilepsy surgery switch in blood fow distribution and temporal lobe seizures. J sion-tensor imaging distinguish epileptogenic tubers and cortex in patients with Nucl Med 1997; 38: 1253–1260. As More than 60 years ago, Marie Brazier  proposed the application a consequence, tissues outside the brain (e. We will frstly: (i) describe the methodological aspects, tive to both tangential and radial components of dipolar sources. Source locali- advances in network analysis based on functional connectivity zation procedures for the two are very closely related and can even and on what these advances have brought to our knowledge of the be combined and optimized for joint source localization. T e equivalent current dipole model Source imaging of interictal spikes: The simplest model of a current source is that of the current dipole methodology and validation produced when an ion fow occurs through the neuronal membrane at the synaptic clef during postsynaptic excitation or inhibition of Equivalent current dipole modelling of interictal spikes pyramidal cell dendrites. If a sufcient number tive statistical estimation of the locations, orientations and ampli- of focal neurons are synchronously activated, as occurs during an tudes of the intracerebral generators from surface signals and this epileptic spike, currents may be obtained with sufcient amplitude requires models for both generators, a term referring to the ana- to produce a measurable potential diference at the surface because tomical structure generating the events, and conductive media. The geometry of neuronal aggregates is of Magnetoencephalography versus electroencephalography particular importance; ‘closed feld’ confgurations (i.
The patella and patellar tendon are then evaluated for abnormalities including infections order antabuse on line medicine bow, anatomic abnormalities effective antabuse 250 mg symptoms 32 weeks pregnant, and fracture (Figs. Color Doppler may help identify neovascularization and hyperemia associated with patellar tendinopathy (Fig. Correct longitudinal position for ultrasound transducer for ultrasound evaluation of the superficial infrapatellar bursa. Ultrasound image of the knee joint demonstrating the superficial infrapatellar bursa. Dashed arrow indicates fragmented apophysis, and calipers indicate bony avulsion from tibia. Longitudinal image of the proximal patella tendon demonstrating severe chronic patellar tendinosis and enthesopathy of the patella. Note the loss of normal tendon architecture and reduced echogenicity (solid arrow). The fat pad has increased echogenicity and has lost the normal fascial lines that demarcate the individual fat lobules, indicative of inflammation. Longitudinal color Doppler image of the proximal patella tendon demonstrating severe tendinosis with marked hyperemia. Other pathologic processes may mimic prepatellar bursitis and judicious use of medical imaging including ultrasound, magnetic resonance imaging, plain radiography, and computed tomography may help clarify the diagnosis (Figs. Given that bursitis is usually the result of either trauma or abnormal function of the affected joint, one should assume that additional pathology other than the bursitis being treated is present. Sagittal proton density (A) and fat-suppressed T2-weighted (B) magnetic resonance images through the knee show an ovoid mass of fat signal intensity within the Hoffa fat pad (arrows). The fatty nature of this intra-articular mass confirms the diagnosis of synovial lipoma. A: Bilateral weight-bearing radiograph of the knees demonstrating degenerative changes and a calcified mass inferolateral to each joint. B: Lateral view of the right knee with evidence of a calcified mass anterior to the proximal tibia. Axial T2-weighted magnetic resonance images of prepatellar bursitis (A) and superficial infrapatellar bursitis (B). Periarticular lesions detected on magnetic resonance imaging: prevalence in knees with and without symptoms. The deep infrapatellar bursa lies between the anterior subcutaneous tissues of the knee and the anterior surface of the patellar tendon (Fig. The bursa serves to cushion and facilitate sliding of the skin and subcutaneous tissues of the anterior inferior portion of the knee over the tibia. The deep infrapatellar bursa is held in place by patellar tendon which is an extension of the common tendon of the quadriceps tendon (Fig. Both the quadriceps tendon and its expansions as well as the patellar tendon and the deep infrapatellar bursa are subject to the development of inflammation caused by overuse, misuse, or direct trauma. The quadriceps tendon is made up of fibers from the four muscles that comprise the quadriceps muscle: the vastus lateralis, the vastus intermedius, the vastus medialis, and the rectus femoris (Fig. The tendons of these muscles converge and unite to form a single, exceedingly strong tendon. The patella functions as a sesamoid bone within the quadriceps tendon, with fibers of the tendon expanding around the patella and forming the medial and lateral patella retinacula, which help strengthen the knee joint. These fibers are called expansions and are subject to strain; the tendon proper is subject to the development of tendinitis. The deep infrapatellar and prepatellar bursae also may concurrently become inflamed with dysfunction of the quadriceps tendon. The deep infrapatellar bursa is held in place by patellar tendon which is an extension of the common tendon of the quadriceps tendon. The quadriceps tendon is made up of fibers from the four muscles that comprise the quadriceps muscle: the vastus lateralis, the vastus intermedius, the vastus medialis, and the rectus femoris. The bursa serves to cushion and facilitate sliding of the patellar tendon over the tibia. The bursa is subject to inflammation from a variety of causes with acute trauma to the knee and repetitive microtrauma being the most common. Acute injuries to the bursa can occur from direct blunt trauma to the anterior knee from falls onto the knee as well as from overuse injuries including running on uneven or soft surfaces or 937 jobs that require kneeling or crawling on the knees like carpet laying and scrubbing floors. If the inflammation of the bursa is not treated and the condition becomes chronic, calcification of the bursa with further functional disability may occur (Fig. Gout and other crystal arthropathies may also precipitate acute deep infrapatellar bursitis as may bacterial, tubercular, or fungal infections. Lateral radiograph of the right knee showing an osseous mass attached to the tibial tubercle. The mass extends to the inferior aspect of the patella and is surrounded by several ossified fragments. Infrapatellar bursal osteochondromatosis associated with unresolved Osgood-Schlatter disease. Physical examination of the patient suffering from deep infrapatellar bursitis will reveal point tenderness over the anterior knee. If there is significant inflammation, rubor and calor may be present and the entire area may feel boggy or edematous to palpation. At times, massive effusion may be present which can be quite distressing to the patient (Fig. Active resisted extension and passive flexion of the affected knee will often reproduce the patient’s pain. If calcification or gouty tophi of the bursa and surrounding tendons are present, the examiner may appreciate crepitus with active extension of the knee and the patient may complain of a catching sensation when moving the affected knee, especially on awaking. Occasionally, the deep infrapatellar bursa may become infected, with systemic symptoms, including fever and malaise, as well as local symptoms, with rubor, color, and dolor being present. Effusion associated with deep infrapatellar bursitis can be appreciated by displacing the patella. Based on the patient’s clinical presentation, additional testing may be indicated, including complete blood cell count, sedimentation rate, and antinuclear antibody testing magnetic resonance imaging or ultrasound imaging of the affected area may also confirm the diagnosis and help delineate the presence of other knee bursitis, calcific tendinitis, tendinopathy, triceps tendinitis, or other 938 knee pathology (Fig. Rarely, the inflamed bursa may become infected and failure to diagnosis and treat the acute infection can lead to dire consequences. Radiograph demonstrating high-energy tibial plateau fractures include primary fracture lines that involve both tibial condyles, severe impaction and comminution of one or both articular surfaces, and fracture extension into the shaft. A,B: Magnetic resonance images of the knee showing abnormal mass in the infrapatellar region consistent with deep infrapatellar bursitis. A linear high frequency ultrasound transducer is placed over the previously identified patella in a longitudinal orientation (Fig. A survey scan is taken which demonstrates the hyperechoic margin of the skin and subcutaneous tissues, the superficial infrapatellar bursa, the patellar tendon, and the deep infrapatellar bursa beneath it (Fig.
This leukemia involves peripheral blood cheapest generic antabuse uk symptoms ear infection, bone marrow order antabuse 250mg visa brazilian keratin treatment, lymph nodes, liver, spleen, and skin. Alterations in T cell antigen expression are observed mainly in advanced tumor stages. Cytotoxic granule-associated proteins are expressed by tumor cells in a few advanced lesions, but are uncommonly positive in early patch/plaque lesions. These are termed Sézary cells and are demonstrable in skin, lymph nodes, and peripheral blood. The pleomor- phic type shows a diffuse proliferation of atypical medium- to large-sized lymphoid cells with irregular nuclei, intermingled with cerebriform giant cells (center). Ki67 rates Immunophenotype: Tumor cells manifest an aberrant T cell >70% portend a worse prognosis (Figures 18. Pleomorphic neo- plastic population, high Ki67 labeling (left insert) and βF1 staining (a) (right insert). By con- trast, nuclear staining alone is more common in the small 101 cell variant. Two-thirds of cases are positive cell membrane and in the Golgi region and is most pro- nounced in the larger cells. All subtypes have an iden- tical immunophenotype and genetic characteristics, but their 101 clinical course and Epstein–Barr virus association differ. Four histological subtypes Immunodefciencies 19 Congenital and Acquired Immunodefciencies are classifed as either primary diseases Immunoincompetence may involve either the B cell limb, as with a genetic origin or diseases that are secondary to an in Bruton’s hypogammaglobulinemia, or the T cell limb, as underlying disorder. The defect in Bruton’s disease is in the Secondary immunodefciencies are more common than the rearrangement of immunoglobulin heavy-chain genes. The best known is acquired immunodef- disorder occurs almost entirely in males and is apparent after ciency disease (e. Patients have recur- individuals develop opportunistic infections caused by rent sinopulmonary infections caused by Haemophilus infu- viruses, fungi, protozoa, and bacteria that are not commonly enzae, Streptococcus pyogenes, Staphlococcus aureus, and pathogenic. Streptococcus pneumoniae, with absent or decreased B cells and decreased serum levels of all immunoglobulin classes. Immunodefciency is a failure in humoral antibody or cell- Thymic hypoplasia (DiGeorge syndrome) occurs when mediated limbs of the immune response. If attributable to the immune system in infants is deprived of thymic infu- intrinsic defects in T and/or B lymphocytes, the condition ence. T cells are absent or defcient in the blood and thymus- is termed a primary immunodefciency. Infants with this from loss of antibody and/or lymphocytes, the condition is condition are highly susceptible to infection by viruses, fungi, termed a secondary immunodefciency. By Primary immunodefciency refers to diminished immune contrast, B cells and immunoglobulins are not affected. It is development failure of a segment of Severe combined immunodefciency (Swiss-type agam- the immune system as a consequence of an inborn genetic maglobulinemia) comprises a group of conditions mani- mutation. Lymph nodes and other peripheral lymphoid tissues Immunodefciency disorders are conditions characterized reveal depleted B and T cell regions. They may be grouped into combined immunodefciency show increased susceptibility four principal categories based on recommendations from a to infections by viruses, fungi, and bacteria, and often suc- committee of the World Health Organization. It can be B cells or T cells or both are presented in greater detail in the secondary to an embryologic abnormality or an enzymatic sections that follow. Types of infections produced in the physical fndings are characteris- Immunoincompetence is the inability to produce a physi- tic of the type of immunodefciency disease. Infants born without a transplantation, enzyme replacement, and gene therapy are thymus or experimental animals thymectomized at birth are all modes of treatment (Figure 19. Children born with severe combined immunodefciency due to one or several causes Congenital immunodefciency refers to a varied group of un are unable to mount an appropriate immune response. Autosomal recessive severe combined Infantile sex-linked hypogammaglobulinemia refers to an immunodeﬁciency antibody defciency syndrome that is sex linked and occurs Lymphoid in males following the disappearance of passively transferred progenitor X-linked severe antibodies from the mother following birth. Serum immu- combined noglobulin concentrations are relatively low, and there is IgM immunodeﬁciency defective antibody synthesis giving rise to recurring bacterial Immunoglobulins Pre-B α and β Immature infections. IgD Hyper-IgM syndrome Hypogammaglobulinemia refers to defcient levels of IgM IgG IgA IgE IgG, IgM, and IgA serum immunoglobulins. Plasma It may be a manifestation of either congenital or acquired cell IgM IgG IgA IgE antibody defciency syndromes. Several types are described and include Bruton’s disease and a congenital type, as well as Figure 19. These include defects in stem cells, Agammaglobulinemia (hypogammaglobulinemia) (Fig- B cells, T cells, phagocytic defects, and complement defects. B cell signaling may lead to one of several primary immunode- fciencies characterized by lack of antibodies. It has been suggested by some that this condition be grouped with the Primary agammaglobulinemia: See antibody defciency genetically determined immunodefciencies. It is a disease characterized by diminished numbers of T lym- IgG, IgA and IgM phocytes, decreased antibody levels, and increased suscepti- missing in patient’s serum bility to respiratory infections, tumors, and radiation injury. Immunodefciencies 619 infections at 5 to 6 months of age after disappearance of to nuclear changes that result in growth and differentiation maternal IgG. Whereas B cells and immunoglobulins are diminished, there is normal T cell function. Repeated Infantile agammaglobulinemia is a synonym for X-linked infections may lead to death in childhood. X-linked agammaglobulinemia is a disease of Btk tyrosine Congenital agammaglobulinemia: See X-linked agamma- kinase that is characterized by an increased susceptibility to globulinemia. There is arrested B cell development at the pre-B cell maglobulinemia that are associated with Epstein–Barr virus stage, which blocks formation of mature B cells and antibody infection. Serum analysis reveals a pronounced decrease in neoplasms which may rupture the spleen. IgA is usually unde- immune response with susceptibility to infection is inherited tectable, and a humoral response to recall antigens is vir- as an X-linked recessive disorder. B lymphocyte and plasma cell numbers are successfully resist infection by the Epstein–Barr virus. B lineage ulin levels are present but the ability to mount an immune cells in all organs are affected, resulting in a reduced size of response to immunogenic challenge is impaired. The defective gene encodes a cyto- dition is associated with several separate disease states and plasmic tyrosine kinase, designated Btk. Some may confrms the diagnosis and can be used to identify healthy present clinically as severe combined immunodefciency carriers. Treatment consists of antibiotics to combat ongoing with diminished cell-mediated immunity, lymphopenia, and infections and γ-globulin substitution as a prophylaxis. There are normal or even elevated numbers of plasma cells, and there Bruton’s X-linked agammaglobulinemia is one of the may be no demonstrable T cell defciency, both of which are more common immunodefciencies. There is a failure of in contrast to the usual clinical picture of severe combined B cell precursors, i. The defect is in rearrangement of immuno- mune reactions and show reduced numbers of lymphoid cells globulin heavy-chain genes. B cell maturation ceases after with surface immunoglobulin in the circulating blood.
The testis is supplied by the testicular artery which arises directly from the descending abdominal aorta at the level of approximately L2 cheap antabuse amex medications you can give your cat. The explanation lies in the fact that the testis develops high up on the posterior abdominal wall early in embryonic life discount antabuse 250 mg on-line treatment questionnaire. As it descends into the scrotum during development, the testis carries with it the same blood supply that it received whence it was positioned on the posterior abdominal wall (i. On the right side, the testis drains by way of the pampiniform plexus into the inferior vena cava, but the left testis drains into the left renal vein. The testis, thus, drains lymph to the para-aortic set of lymph nodes, since the testicular artery arises from the aorta. The clinical consequence of this is that a testicular carcinoma metastasises to the para-aortic group of lymph nodes and never results in inguinal lymphadenopathy, unless the scrotum is also involved. Thus, a renal calculus may refer pain down to the testis, as is seen in classical renal colic. Skin Subcutaneous tissue (containing dartos muscle) Colles’ fascia External spermatic fascia (external oblique) Cremaster muscle and fascia (internal oblique/transverses abdominis) Internal spermatic fascia (transversalis) Parietal layer of tunica vaginalis Visceral layer of tunica vaginalis Tunica albuginea of testis Ureters What type of muscle do the ureters consist of? The ureters are segmental muscular tubes, 25 cm long, composed of smooth (involuntary) muscle throughout their entire length. The ureters are lined by transitional epithelium (urothelium) throughout their length. Transitional epithelium is almost exclusively confined to the urinary tract of mammals where it is highly specialised to accommodate stretch and to withstand the toxicity of the urine. How may the ureters be identified at surgery so as to prevent inadvertent ligation? The ureter is characteristically a whitish, non-pulsatile cord, which shows peristaltic activity when gently pinched with forceps (i. The upper third is supplied by the renal arteries, the middle third from branches given off from the descending abdominal aorta and the lower third is supplied by the superior and inferior vesical arteries. Consequently, the middle third of the ureter is most vulnerable to post-operative ischaemia and stricture formation if blood supply to it is endangered by stripping the ureter clean of its surrounding tissue at surgery. Along the course of the ureter are three narrowings that often form the site of obstruction in ureteric calculus disease: Pelvi-ureteric junction Where the ureter crosses the pelvic brim in the region of the bifurcation of the common iliac artery Vesico-ureteric junction the vesico-ureteric junction is the point of narrowest calibre. In both sexes, the ureters run obliquely through the bladder wall for 1–2 cm before reaching their orifices at the upper lateral angles of the trigone. This forms a flap valve preventing reflux of urine retrogradely back up the ureters. As with all joints, stability is brought about by the way the various bones articulate with one another (through their incongruous surfaces) and through the various ligaments, tendons and muscles that surround the joint. Stability is achieved largely as a result of the adaptation of the acetabulum and femoral head to one another, with a snug fit of the femoral head into the acetabulum, deepened by the labrum and further reinforced by three ligaments on the outside of the capsule (the iliofemoral, ischiofemoral and pubofemoral ligaments). Since the hip is such a stable joint, it requires considerable force to become dislocated. When it does occur, it usually dislocates in the setting of a road traffic accident, where typically the hip joint dislocates posteriorly. The hip joint lies deep to the pulsation of the femoral artery at the mid-inguinal point (half way between the anterior superior iliac spine and the symphysis pubis). Consequently, the sciatic nerve is at risk in a posterior surgical approach to the hip, or in a posterior dislocation. The hip joint is innervated by the sciatic, femoral and obturator nerves (Hilton’s Law). In a child that presents with a painful knee, always examine the ipsilateral hip joint, in addition to examining the knee, to avoid missing a diseased hip. Most importantly, via retinacular vessels that run up from the trochanteric anastomosis and then along the neck of the femur to supply the major part of the head. The trochanteric anastomosis is formed by an anastomosis of the medial and lateral circumflex femoral arteries and the superior and inferior gluteal arteries. Via the nutrient, or diaphyseal, artery of the femur, originating from the second perforating artery of the profunda femoris artery. An intra-capsular fractured neck of the femur may disrupt the retinacular fibres and consequently disrupt the blood flow to the femoral head resulting in avascular necrosis. Garden 1 and 2 fractures are undisplaced fractures, whilst 3 and 4 are displaced fractures. The exception is the young patient with a 3 or 4 where the aim is to try and save the hip and therefore open reduction and internal fixation with cannulated screws is preferable in the first instance to avoid multiple hip revisions in the patient’s lifetime. The shoulder joint, like the hip joint, is a synovial joint of the ball and socket variety. Coracobrachialis Pectoralis minor Short head of biceps What important nerve lies in close proximity to the shoulder joint? It must never be forgotten that the axillary nerve lies in close proximity to the shoulder joint and the surgical neck of the humerus. Consequently, it is vulnerable to injury at the time of a shoulder dislocation, or whilst attempting to reduce the shoulder back into its normal position following a dislocation. It is therefore imperative (from both a clinical and medico-legal point of view) that the integrity of the axillary nerve is documented, both after seeing the patient who has a dislocated shoulder, but also following successful reduction. The knee joint is a synovial joint (the largest in the body), of the modified hinge variety. The cruciate ligaments are two very strong ligaments that cross each other within the joint cavity, but are excluded from the synovial cavity by a covering of synovial membrane (they are therefore described as being intra-capsular, but extra- synovial). Thus, the anterior cruciate ligament is attached to the anterior inter-condylar area of the tibia and runs upwards, backwards and laterally to attach itself to the medial surface of the lateral femoral condyle. Backward displacement of the tibia on the femur is prevented by the stronger posterior cruciate ligament which runs from the posterior part of the tibial inter- condylar area to the lateral aspect of the medial femoral condyle. The integrity of the latter is therefore important when walking down stairs or downhill. Tears of the anterior cruciate ligament are common in sports injuries; tears, however, of the posterior cruciate ligament are rare since it is much stronger than the anterior cruciate. Bursae are lubricating devices found wherever skin, muscle or tendon rubs against bone. An effusion of the knee may therefore extend some three to four finger breadths above the patella into the supra- patellar pouch. The pre-patellar and infra-patellar bursae do not communicate with the knee joint, but may become inflamed causing a painful bursitis. Inflammation of the pre-patellar bursa is known as housemaid’s knee, whereas that of the infra-patellar bursa is called clergyman’s knee. The menisci, or semilunar cartilages, are cresent-shaped laminae of fibrocartilage, the medial being larger and less curved than the lateral. Contributing to stability of the knee by their physical presence and by acting as providers of proprioceptive feedback 3. Probably assisting in lubrication the menisci are so effective that if they are removed, the force taken by the articular hyaline cartilage during peak loading increases by about five-fold. Meniscectomy (removal of the menisci), or damage to the menisci, therefore exposes the articular hyaline cartilage to much greater forces than normal and evidence of degenerative osteoarthritis is seen in 75% of patients 10 years after meniscectomy.