Ebook Key topics in sports medicine: Part 2

Infection and sport 153 Knee injuries CT is particularly useful when evaluating tibia plateau fractures. Acknowledgements We would like to thank Dr B Langroudi for his comments on this and other chapters on imaging. Further reading Barron D. Basic science: computed tomography. Current Orthopaedics 2005; 19: 20–6. Gibbon WM, Long G. Imaging of athletic injuries. Current Orthopaedics 2000; 14: 424–34. Sanders TG, Fults-Ganey K. Imaging techniques. In: JC DeLee, D Drez, MD Miller (Eds) Orthopaedic Sports Medicine, Principles and Practice, 2nd edn. Saunders, 2002: 557–614. Tung GA, Brody JM. Contemporary imaging of athletic injuries. Clinics in Sports Medicine 1997; 16(3): 393–417. Infection and sport A Kamvari On the whole, regular moderate exercise is believed to enhance immunity and decrease susceptibility to infections, such as the common cold and also some forms of cancer, whereas sudden intense exercise and over-training appears to have a deleterious effect on the immune response and may be a limiting factor in athletic performance. An overall view of this situation has been graphically described by Nieman’s “J-curve”, which is emphasised as being descriptive rather than quantitative (see Nieman 1994). Exercise – immune interactions Effects of exercise on the physical barriers to infection Cooling and drying of the respiratory mucosa causes an increased exposure of the bronchi to viral and carcinogenic particles in the air during exercise, due to a switch in nose-to-mouth breathing and also turbulent and high respiratory flow rates. This in turn reduces cilial motility, which increases mucus viscosity in the bronchi, and thus reduces clearance of the contaminated particles, which can increase the susceptibility of the athlete to viral respiratory infections and certain cancers. Effects of exercise on the biologic immune defences Cellular changes • Leukocyte subpopulations: “leukocytosis of exercise” is one of the earliest and most consistent observations of the exercise-induced immune response in the blood. 154 Sports Medicine • Natural Killer (NK) cells and Lymphokine-activated Killer (LAK) cells increase their activity as well as their concentration in the blood. • Phagocytic cells increase in numbers during exercise. Humoral changes • B Cell Function is not well studied but immunoglobulins (IgA, IgM, IgG) are all depressed during, and two hours post, exercise, but this is a transient change and their concentrations recover after 2 hours. • Cytokines. Exercise increases production of IL-1, which has a direct cytotoxic effect. It also increases the production of IL-2, IL-6 and tumour necrosis factor (TNF) in plasma. On the whole, using experimental and epidemiological data, and taking other factors that influence athletes’ susceptibility to infection (e.g. pathogen exposure, diet, psy-chological influences and environmental stresses) into consideration, it has been shown that excessive and stressful exercise weakens resistance to infections and renders athletes more susceptible to frequent and persistent colds, sore throats and influenza-like illnesses. Moderate exercise and training, however, seem to increase immune functions, especially amongst the older age groups. Upper Respiratory Tract Infections (URTIs) in athletes These are a spectrum of illnesses, which include infectious rhinitis (common cold), pharingitis and sinusitis. Epidemiology The average adult population has two to four colds per year, mostly during the winter months. Aetiology • Viral: Most URTIs are caused by viruses, transmitted by secretion, contamina-ted hands or direct droplet transmission through hand contact with the eyes or nose. Infectious rhinitis – mostly caused by rhinoviruses. Pharyngitis – mostly caused by rhinovirus, coronavirus, parainfluenza virus or res-piratory syncytial virus. Other viral agents include herpes simplex and coxsack-ievirus and adenovirus. Epstein–Barr virus and cytomegalovirus can also cause pharyngitis, but they also cause other severe systemic symptoms including fatigue, lymphadenopathy, splenomegaly and fever. • Bacterial: Beta haemolytic Group A streptococcus, chlamydia pneumoniae. Symptoms and signs Mild chills and fatigue followed by clear rhinorrhea, congestion, scratchy sore throat, cough, congestion and headache are the most common symptoms. Patients with bacterial sinusitis often present with a history of purulent rhinorrhea, unilateral sinus or periorbital pain. On examination, vital signs are normal, but an occasional low-grade fever may be found. The throat often appears erythematous with exudates and, occasionally, Infection and sport 155 petechiae. Anterior cervical nodes may be swollen and tender. Tenderness over the sinus regions may be present. Investigations and treatment Diagnosis of URTIs are usually clinical and do not require further investigation and testing. Occasionally, if bacterial causes are suspected, throat swabs and cultures may be done to isolate the organisms responsible. If chronic bacterial sinusitis is suspected a percutaneous sinus aspiration and culture can also be done, but this is usually an impractical procedure for routine diag-nostic testing. Imaging with CT and plain radiography can be done if recurrent or chronic sinusitis occurs, which can find mucosal thickening, sinus opacification and altered fluid levels in the sinuses. Symptoms of viral URTIs usually improve within 5 to 7 days and abate within 10 to 14 days spontaneously, with no treatment. Vitamin C and zinc supplements have been found to decrease the period and extent of morbidity. Oral decongestants and antihistamines, paracetamol and ibuprofen can all be used symptomatically. Antibiotics are only given if bacterial causes are suspected or isolated. The antibiotic of choice for group A streptococcus infections is Penicillin V, but amoxicillin may also be substituted. Return to sport The conventional guidance is that athletes should refrain from exercising in the pres-ence of systemic symptoms that include fever, severe myalgia or lethargy, and tachy-cardia at rest or severe respiratory symptoms that include wheezing, shortness of breath and deep cough. Infectious mononucleosis Epidemiology Mainly affects adolescents and young adults in developed countries and young chil-dren in developing countries. Aetiology Infectious mononucleosis is mostly due to Epstein–Barr virus (EBV), less commonly cytomegalovirus (CMV). Symptoms and signs Classically presenting symptoms include fever and sore throat, some patients may present with a maculopapular rash, fatigue and left-sided abdominal discomfort due to splenomegaly. There may also be neurological symptoms ranging from encephalitis to a peripheral neuropathy. On examination, tonsillar hypertrophy with exudates and also generalised lym-phadenopathy may be found. Jaundice and haematological abnormalities (thrombo-cytopenia or haemolytic anaemia) may also be found. 156 Sports Medicine Investigations and treatment Blood tests generally show an increase in white blood cell count of 10,000 to 20,000/mm3 with increased atypical lymphocytes. Serological tests for EBV and CMV IgM and IgG can provide direct evidence of acute or prior infection. A positive heterophile antibody (Monospot) test is diagnostic. Infectious mononucleosis is generally self-limiting, and symptoms usually last from 2–6 weeks. Treatment is therefore mainly symptomatic, and rest. Corticosteroids are not usually recommended unless there is airway compromise, when the drugs can significantly reduce tonsillar hypertrophy. Complications Splenic rupture – up to 40% of traumatic splenic ruptures have occurred in athletes who have been found to have infectious mononucleosis. Most splenic ruptures occur in patients with splenomegaly, but it can happen to patients who do not have an enlarged spleen. Non-traumatic splenic rupture usually occurs between weeks 2 and 4 with an incidence of 1 in 1000. Persistent fatigue – in a few patients fatigue and lethargy can continue for an indef-inite period of time after the rest of the symptoms have been resolved. Airway obstruction – this can occur if there is severe tonsillar hypertrophy. Return to sport Even though total bed-rest is unnecessary, athletes should generally be restricted from training and competing for 3 to 4 weeks. Athletes returning to contact sports such as rugby or wrestling should refrain from doing so until the resolution of splenic enlargement. Further reading Howe WB. Preventing infectious disease in sports. The Physician and Sports Medicine 2003; 31(2). Nieman DC. Exercise, infection and immunity. International Journal of Sports Medicine 1994; 15(Suppl 3): S131–41. O’Kane JW. Upper respiratory infection. The Physician and Sports Medicine 2000; 30(9). Shepard RJ. Exercise, immunity, and susceptibility to infection – a J-shaped relationship. The Physician and Sports Medicine 1999; 27(6). Knee – acute injuries P Thomas The different anatomical structures will be discussed separately, although injuries involving more than one structure can also exist. Knee – acute injuries 157 Anterior cruciate ligament This is an intracapsular structure, attached proximately at the posterolateral femur and distally on the tibial spine. The anterior cruciate ligament (ACL) resists anterior displacement of the tibia on the femur. Also, as the knee extends it rotates the tibia externally assisting to “drive” the tibia under the femur. The usual mechanism of injury includes, in contact sports such as football and rugby, an excessive rotation force on the tibia or a hyperextension of the knee, which usually occurs when a skier falls backwards. Other more complex and multi-directional forces can also lead to an ACL, usually associated with other knee anatomical structure injuries. Swelling, caused by an acute haemarthrosis is present in almost all patients. Many athletes describe an audible “pop” at the time of the injury. The knee is also painful. On examination there is effusion present into the knee joint. Seventy-five to 80% of all acute haemarthosis in the knee joint following trauma are usually associated with an anterior cruciate ligament rupture. The tenderness is diffused or present posterolaterally in cases of lateral meniscus tears and posterior capsular damage or medially if there is an associated medial meniscus tear. The anterior draw test may be negative due to muscle spasm, however the Lachman’s test is always positive with a soft or no “end point”. In experienced hands, the pivot shift test is also positive. X-rays may be entirely normal or may demonstrate an avulsion of the tibial spine, more often seen in the young athlete, or Segond’s fracture may be present, which is usually associated with an ACL rupture. Management consists of: Conservative • 4–6 weeks’ rehabilitation programme to absorb the effusion, restore painless range of movement of the knee joint, regain full muscle strength and proprioception such as side-stepping exercises and “figure of 8” running. • After this, the patient may be able to return to his sport or will carry on to surgical reconstruction of the ACL, in particular if the knee is unstable on returning to sport or even in daily activities. The individual should be discouraged to continue sport with frequent episodes of instability. Recurrent instability may damage the menisci and the articular cartilage, leading to degeneration and osteoarthritis. • Derotation braces are still controversial. They may help with stability in some sports such as skiing, tennis or squash. Surgery • The decision for a surgical reconstruction will be based on whether the patient is young, with recurrent instability, the level of sporting activity and the personality of that patient. • During surgery, an autograft from hamstrings, patella tendon or quadriceps is the popular choice among surgeons and will be placed arthroscopically into the knee joint. Allografts and synthetic ligament materials are also used worldwide. • A prolonged rehabilitation programme is undertaken to allow the patient to return to competitive sport between 6 months to 1 year. In the hands of an experienced surgeon the success rate following surgery approaches 90%. ... - tailieumienphi.vn