Nội dung

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, psychological 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, contaminated 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 respiratory syncytial virus. Other viral agents include herpes simplex and coxsackievirus 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 diagnostic 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 presence of systemic symptoms that include fever, severe myalgia or lethargy, and tachycardia 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 children 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 lymphadenopathy may be found. Jaundice and haematological abnormalities (thrombocytopenia 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 indefinite 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 multidirectional 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%. 158 Sports Medicine • The long-term risk of osteoarthritis is unclear, although many publications have suggested that in knees where the ACL is reconstructed then the stability is restored and this reduces the risk of further articular cartilage damage and menisci tearings, therefore reducing the probability of degenerative disease and osteoarthritis. Certainly, a reconstruction of the ACL allows continued sports participation with all its benefits. Chronic anterior cruciate ligament deficient knee Symptoms include: giving way, recurrent swelling, pain and locking. The diagnostic tests such as anterior draw test, Lachman’s, pivot shift and menisci tests are more obviously positive than the acute rupture of the anterior cruciate ligament. Degenerative disease with crepitus and compartmental pain on movement may be present. An effusion may or may not be present. Arthroscopic surgery may be indicated for the torn menisci and chondroplasty could be performed for frail articular cartilage. A reconstruction is indicated when instability is present with daily activities. The rehabilitation programme is similar as for the acute anterior cruciate ligament reconstruction. Posterior cruciate ligament The posterior cruciate ligament (PCL) is an intra-articular but extrasynovial structure, whose course runs from the posterior of the tibia upwards and forwards where it becomes wide at the attachment in the medial femoral condyle. The function of the PCL is to resist the femur slide over the tibia and also to resist hyperextension of the knee joint. Mechanism of the injury usually is either a direct blow to the anterior tibia when the knee is flexed or severe hyperextension of the knee joint. The athlete presents with pain or the feeling of “giving way” when he runs downhill or downstairs. Later on, he will complain of pain at the patellofemoral joint because the patella articular cartilage is damaged as the femur slides forward on the tibia. An avulsion of the tibia attachment is common in the young athlete. On clinical examination, an increased recurvatum, posterior sag of the tibia and a positive posterior draw test may be observed. In patients with posterior cruciate ligament tibial avulsions, primary surgical repair will produce excellent results. Conservative management is successful in most of the patients, achieving full range of movement of the knee joint, strong quadriceps, flexible hamstrings and gradual return to sport with some alterations in training. Surgical reconstruction is reserved for patients with multiple ligament injuries, or in the few cases of an isolated rupture with continuous functional instability, despite conservative management. Medial collateral ligament This represents the most common ligament injury of the knee joint. The mechanism of injury includes a direct valgus force applied to the knee or a force that increases the external tibial rotation. Knee – acute injuries 159 Three degrees of injury are recognized: First degree • There is pain locally, there is no swelling and valgus stress at 30° of flexion is negative (no medial side opening). Second degree • Pain is present locally, there is some swelling and valgus stress at 30° of knee flexion will be positive but with an end point. Third degree • Pain is present locally, there is swelling, valgus stress at 30° of knee flexion is positive with no end point and it is usually associated with other ligamentous injury of the knee joint. The management of the medial collateral ligament injuries is largely conservative. The patient is able to return to his or her sporting activities when there is minimal tenderness at the ligament site, the valgus stress test is pain free, there is full range of movement of the knee joint, and the patient can run and change direction without any pain. Recovery takes place between 2 weeks to 3 months. Pellegrini–Stieda disease This is associated with heterotopic ossification which develops at the disrupted femoral attachment origin of the medial collateral ligament. Symptoms and clinical findings include increased pain, severe localized tenderness and restriction because of discomfort in both flexion and extension of the knee joint. X-rays will reveal the pathology but usually 3–4 weeks later on from the injury. Management includes active mobilization, local infiltration with a corticosteroid agent, aspiration under ultrasound scan guidance and on occasions surgical excision if the ossification is too large. Lateral collateral ligament, posterolateral corner The mechanism of injury includes a direct varus force applied to the knee joint or it is a part of a more complex pattern, with damage at the posterolateral corner of the joint. In the majority of cases, surgical management as part of the early exploration of the posterolateral corner complex of the knee is mandatory. Surgical reconstruction in chronic cases is indicated. Meniscus The medial meniscus is less mobile compared with the lateral one since the middle third is attached to the joint capsule and the deep layer of the medial collateral ligament. The meniscus is a load-bearing structure which functions as a “shock absorber”. The wedge shape reduces the anatomical disparity between femur and tibial surfaces, therefore contributing to joint stability. It also contributes to the nutrition of the articular cartilage. A total menisectomy will lead to alteration of the load and stability of the knee joint compartment, leading to degeneration and osteoarthritis. All surgical treatments are aiming to preserve as much meniscus as possible following a tear (repair or partial menisectomy). 160 Sports Medicine The patient will complain of localized joint pain, locking and giving way. On occasions a small amount of swelling can be present. A true locking of the knee represents a loss of the last few degrees of knee extension and is usually associated with a “bucket handle” tear of the meniscus, which is displaced into the knee joint. Associated meniscal cysts may be present, usually at the lateral side of the knee joint. Clinical tests of McMurray and Apley’s compressive tests will both be positive. MRI scans are highly diagnostic and have replaced arthrography. The management of suspected meniscal tears may involve a period of conservative treatment with rest from activities and physiotherapy. Persisting symptoms beyond 3–4 weeks will lead to arthroscopic surgery where partial menisectomy or repair of the tear with sutures will be performed. Management of a locked knee will involve arthroscopic surgery and depending on the time of the presentation, repair or excision of the torn peripheral meniscus will be attempted. A lateral meniscal cyst may be treated by arthroscopic means but, in cases of recurrence, removal by open surgery may need to be considered. Patellofemoral dislocation This usually occurs with a sudden internal femoral rotation on the fixed tibia. The patella dislocates laterally and may spontaneously reduce. Predisponding factors may include: • • • • • • • • increased femoral antiversion valgus knee, high patella (patella alta) tight patella retinaculum shallow femoral groove underdeveloped lateral femoral condyle overpronated feet weak vastus medialis wide Q angle. The diagnosis is easily made if the patella is still dislocated. In cases where the dislocation is reduced the clinical examination may reveal the presence of a haemarthrosis, tender medial patella retinaculum, painful contractions of the quadriceps and a positive Apprehension test. Management includes the immediate reduction of the dislocation and aspiration of any haemarthrosis. A period of immobilization in a cast or a brace, usually in extension, for a period of 3 weeks is recommended. Then exercises for flexion and gradual range of movement of the knee joint are commenced. This is followed by rehabilitation and strengthening of the vastus medialis. Return to sport will be encouraged when the quadriceps are strong, proprioception is present and the knee is symptom free. A sleeve-type brace is worn when returning to sport, providing additional proprioceptive feedback, reducing the risk of a further dislocation. The presence of recurrent instability will lead to a decision of surgical management. Knee – overuse injuries 161 Other knee injuries Fractures • By definition intra-articular, and in most cases will lead to a decision of open reduction and internal fixation. Osteochondral fractures • They are commonly associated with patellofemoral instability, they simulate a meniscus injury with pain and locking. Arthroscopic surgery is the treatment of choice. Ruptures of the extensor mechanism of the knee • In most of the cases the patella tendon can rupture, less often this injury can occur on the quadriceps tendon in an older athlete. The diagnosis is made by the inability to straight leg raise and the treatment consists of an acute direct surgical repair. Further reading Fowler PJ et al. Isolated PCL injuries in athletes. Am J Sports Med 1987; 15: 553–7. Hardin GT et al. Meniscal tears: diagnosis, evaluation and treatment. Orthop Rev 1992; 26: 1311–17. Johnson RJ et al. Current concepts review: the treatment of injuries of the ACL. J Bone Joint Surg 1992; 74A: 140–51. Knee – overuse injuries P Thomas Iliotibial band friction syndrome The iliotibial band is a tendon within the fascia lata inserting into the Gerdy’s tuberle on the anterior lateral aspect of the tibia. The iliotibial band drops posteriorly behind the lateral femoral epicondyle during knee flexion, then snaps forward over the epicondyle during the extension phase. This syndrome is the result of the inflammation of the distal iliotibial band and the bursa, which lies underneath it and over the lateral femoral condyle. Predisponding factors will include: genu varus, excessive feet pronation, any leg length discrepancy, a prominent Greater Trochanter of the upper femur and training errors, e.g. a single run over excessive distance or increasing the running mileage too quickly, excessive hill running. The pain at first is present going down stairs or downhill. Later on, continuous pain will be present, restricting all running or even daily activities. Tenderness is present 2–3 cm above the lateral joint line at the lateral femoral epicondyle with the knee flexed at 30°. Palpable crepitus may also be present. Ober’s test is positive. 162 Sports Medicine The management at first will include rest, ice and anti-inflammatories. Physiotherapy will include localized treatments, stretching of the hip abductors and flexors. Foot orthotics are recommended for any biomechanical discrepancies. At the site of friction, injection of corticosteroid could also be attempted. In persistent cases surgery, with division of the iliotibial band 3 cm above the knee joint at the anteriolateral femoral condyle, may be offered. Popliteus tendinitis This is a less common condition than the iliotibial band friction syndrome, however the same predisponding factors could be associated with this condition. Athletes experience pain which may be reproduced by resisted knee flexion with the tibia held in external rotation. The management will include rest, ice and compression, anti-inflammatories and localized soft tissue treatments, electrotherapy modalities and stretching of the knee flexors. In more resistant cases the site can be injected with a corticosteroid agent. Pes anserinus bursitis At the insertion of the hamstrings at the anterior medial aspect of the tibia there is a bursa present that can become inflamed and cause localized discomfort. The athlete’s complaint will concentrate in localized burning and tenderness. The condition is associated with repeated hamstring injuries or even tight hamstrings. The management includes rest, ice and compression, hamstring stretching, anti-inflammatories, orthotics for overpronated feet and local infiltrations using a corticosteroid. Further reading Taunton JE, Clement DB, Smart GW, McNicol KL. Non-surgical management of overuse knee injuries in runners. Can J Sports Sci 1987; 12(1): 11–18. Knee – anterior knee pain P Thomas Patellofemoral joint-related pain Females are affected more compared to males. It is usually seen in adolescence as chondromalacia patellae and in the fourth to fifth decades of life. The predominant symptom is pain anteriorly aggravated by climbing stairs, walking on hills and after a prolonged sitting down position. Crepitus may be present too. Clinical examination reveals irritability of the patellofemoral joint. Biomechanical factors associated with the condition include a wide Q angle, which is above 15° in males and 18° in females,