ACL and PCL pathophysiology

ACL Tears

-1) rotation of the knee while foot is planted followed by a force that drives the tibia anteriorly and the femor posteriorly, or (2) hyperextension

-Isolated ACL injury is uncommon Trauma to the PCL may provide a false positive for ACL injury

-Usually injury results from non-contact sport activity in which an athlete cuts or pivots quickly (ie. soccer)

- Predisposing factors to ACL injury may include: ACL size, joint laxity, muscular and athletic skill coordination, body motions, limb alignment, and menstrual cycle (increased laxity with estrogen and progesterone surges during the luteal phase)

-Females experience ACL sprains at higher rate than men



PCL Tears

-Pcl lig are stronger then Acl ligs

-Mode of injury is often due to posterior force to tibia

-Eg. Smashing your tibia into the dashboard during an accident

-Also a result of hyperextension



Other Fact that might not change your life but might help^_^

-The tensile strength streagth and the load it can bear of the PCL is greater than that of the ACL

-ACL is involved in 85% of anterior translation of the tibia

-PCL is fully involved in the posterior translation of the tibia

-Once injured the sub laxity of the ACL ligament make the joint more prone to injury

Knee examination

A complete knee examination is always done for a knee complaint. Both of your knees will be checked, and the results for the injured knee will be compared to those of the healthy knee. Your doctor will also check that the nerves and blood vessels are intact.

Your doctor will:
-Inspect your knee visually for redness, swelling, deformity, or skin changes.
-Feel your knee (palpation) for warmth or coolness, swelling, tenderness, blood flow, and sensation.
-Test your knee's range of motion and listen for sounds. In a passive test, your doctor will move your leg and knee joint. In an active test, you will use your muscles to move your leg and knee joint. At the same time, your doctor will listen for popping, grinding, or clicking sounds.

Check your knee ligaments, which stabilize the knee. Tests include:
-The Valgus and Varus tests , which check the medial and lateral collateral ligaments. In these tests, while you lie on the examining table, your doctor places one hand on your knee joint and the other on your ankle and moves your leg side-to-side.
-The posterior drawer test , which checks the posterior cruciate ligament. In this test, you lie on the table with your knee bent at a 90-degree angle and your foot flat on the table. Your doctor will put his or her hands around your knee and push the top of your knee with the thumb.
-The Lachman test , which checks the anterior cruciate ligament (ACL). In this test, while you lie on the table, your doctor will slightly bend your knee and hold your thigh with one hand. With the other hand, he or she will hold the upper part of your calf and pull forward. The Lachman test diagnoses a complete ACL tear.
-A pivot shift test , which checks the ACL. In this test, the leg is extended and your doctor holds your calf with one hand while twisting the knee and pushing toward the body. It is often done just before a knee arthroscopy and after anesthesia has completely relaxed the muscles.
-A McMurray test may be done if your doctor suspects a problem with the menisci based on your medical history and the above examinations. In this test, while you lie on the table, your doctor holds your knee and the bottom of your foot. He or she then pushes your leg up (bending your knee) while turning the leg and pressing on the knee. If there is pain and the sound or feeling of a click, the menisci may be damaged.

Arthrometric testing of the knee may also be done. In this test, your doctor will use an instrument to measure the looseness of your knee. This test is especially useful in people whose pain or physical size makes a physical exam difficult. An arthrometer has two sensor pads and a pressure handle that allows your doctor to put force on the knee. The instrument is strapped on to your lower leg so that the sensor pads are placed on the knee cap and the small bump just below it (tibial tubercle). Your doctor then measures pressure by pulling or pushing on the pressure handle.

Your exam may also include other tests to assess the degree of the injury and to identify damage to other parts of the knee.

Why It Is Done
A complete physical exam of the knee is always done for a knee complaint, whether the complaint is from a recent or sudden (acute) injury or from long-lasting or recurrent (chronic) symptoms.

Results
In general, in a normal knee exam:
The knee has its natural strength.
The knee is not tender when touched.
Both knees look and move the same way.
There are no signs of fluid in or around the knee joint.
The knee and leg move normally when the ligaments are examined.
There is no abnormal clicking, popping, or grinding when knee structures are moved or stressed.
The toes are pink and warm, and there is no numbness in the lower leg or foot.

If any of these findings are not true-for example, the knee is tender-you may have a knee injury. But the results of a knee exam vary depending on whether the exam is for a sudden injury to the knee or for long-term symptoms and also depending on how long it has been since the injury occurred. An abnormal finding does not always mean that your knee is injured. Your doctor will use the results of the exam, plus your medical history, to make a diagnosis.

What To Think About
These tests provide the best information if there is little or no knee swelling, you are able to relax, and your doctor is able to move your knee and leg freely. If this is not the case, it may be difficult to accurately check your knee.

If your knee is red, hot, or very swollen, a knee joint aspiration (arthrocentesis) may be done, which involves removing fluid from the knee joint. This is done to:
-Help relieve pain and pressure, which may make the physical exam easier and make you more comfortable.
-Check joint fluid for possible infection or inflammation.
-See if there is blood in the joint fluid, which may indicate a tear in a ligament or cartilage.
-See if there are drops of fat, which may indicate a broken bone.
-Local anesthetic may be injected after aspiration to reduce pain and make the exam easier.

If you are going to have arthroscopy, the knee may be examined in the operating room before the procedure, while you are under general or spinal anesthesia.


very useful link on knee exam:- (though i doubt any of you would actually click on it)
http://www.sportsdoc.umn.edu/Clinical_Folder/Knee_Folder/knee.htm

Generalized Anxiety Disorder

Generalized Anxiety Disorder

Anxiety is a complex feeling of apprehension, fear, and worry often accompanied by pulmonary, cardiac, and other physical sensations. It is a common condition that can be a self-limited physiologic response to a stressor, or it can persist and result in debilitating emotions. When pathologic, it can exist as a primary disorder, or it can be associated with a medical illness or other primary psychiatric illnesses (eg, depression, psychosis).

Mental health disorders account for approximately 5.5% of emergency department (ED) visits and, among these mental health visits, 21% are due to anxiety. Because generalized anxiety disorder (GAD) and panic attacks present with a similar constellation of symptoms, a similar approach can be used for both.

The goal of the emergency physician (EP) is to differentiate whether the anxiety is due to an acute medical condition or is the primary diagnosis. This differentiation can be difficult since many anxiety symptoms are indistinguishable from common cardiopulmonary and neurological complaints. Unfortunately, a chaotic emergency department is not the best environment to take a detailed history of the symptoms or to comfort an anxious patient. In addition, because of the high volume of ED’s nationally, EPs are under great pressure to see patients faster. Anxiety, like other psychiatric diagnoses, requires more time to take a history and engage the patient about the underlying cause of the symptoms.

Pathophysiology

Heightened physiologic response and elevated catecholamine levels play an important role in the normal physiologic response of the body to stress and anxiety. Pathologic anxiety has been hypothesized to result from disturbances in the cerebral cortex, specifically the limbic system.

The neurotransmitters primarily associated with anxiety in these regions are norepinephrine, gamma-aminobutyric acid (GABA), and serotonin. The efficacy of benzodiazepines in treating anxiety has implicated GABA in the pathophysiology of anxiety disorders. Drugs that affect norepinephrine (eg, tricyclic antidepressants, monoamine oxidase inhibitors [MAOIs]) are also efficacious in the treatment of several anxiety disorders.

Clinical

History

• The initial assessment must include a complete history with a focus on the patient's social history and a discussion of possible recent stressors (eg, problems with employment, financial stress, recent family illness/death, spousal conflict/abuse, illicit drug use). In addition, a detailed dietary history is critical. Caffeine, nicotine, chocolate, over-the-counter "exercise" or weight loss pills, and other natural supplements are often implicated as causes of an acute anxiety attack. Patients often do not realize that these agents are stimulants and can cause pronounced palpitations and other signs of anxiety.
• The family is an excellent source of history for a patient with acute anxiety and may be able to provide information that the patient is reluctant to discuss or does not feel is relevant to the presentation.
• The Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV) classifies anxiety disorders as follows¹ :
• Global anxiety disorder (GAD) requires a clinical duration of at least 6 months. GAD occurs frequently with mood disorders (eg, major depression).
• Panic disorder with or without agoraphobia: Panic attacks are recurrent episodes of spontaneous, intense periods of anxiety, usually lasting less than 1 hour. Panic attacks accompany complications of agoraphobia within the first year. (Agoraphobia is a condition involving anxiety about being in places or situations where escape might be difficult.). Patients with panic attacks are often in significant distress and seek medical attention in the ED. A patient with a classic panic attack experiences at least 4 of the following symptoms: palpitations, diaphoresis, tremulousness, shortness of breath, chest pain, dizziness, nausea, abdominal discomfort, fear of injury or going crazy, derealization (perception of altered reality), and depersonalization (perception that one's body is surreal).
• Anxiety disorder due to a general medical condition is itself a unique diagnosis, but the emergency practitioner must thoroughly evaluate the known medical problem before making this diagnosis.
• Substance-induced anxiety disorder and anxiety disorder not otherwise specified are characterized by symptoms of anxiety that occur as a direct consequence of drug abuse, medications, or toxins.

Physical

• While the physical examination of patients with anxiety is often normal, a great deal can be learned from observing the patient during the ED visit. The general demeanor, appropriateness, insight, hygiene, mood, cognitive capacity, and ability to engage the clinician in a discussion of the symptoms. However, a good physical examination allows the emergency physician to identify any potential life-threatening illnesses. The clinician should focus on the signs and symptoms of anxiety. Examination results may guide laboratory and imaging studies needed to evaluate cardiopulmonary causes of anxiety.
• As can be expected, comorbid diseases have their own characteristic examination findings.
• Mental status examination
• A mental status examination can be especially helpful in distinguishing functional from organic disorders. Differentiating among the numerous psychiatric illnesses is essential, as many share symptoms similar to those of anxiety disorders.
• The examination should focus on the following:
• Affect
• Behavioral observation
• Speech pattern
• Level of attention
• Language comprehension
• Memory, calculation, and judgment

Causes

• Comorbid diseases have been known to cause intrinsic anxiety. Many abused drugs (eg, alcohol, amphetamines, narcotics) raise anxiety levels.
• Panic attacks in patients who are susceptible to them can be precipitated by caffeine or iatrogenic agents, such as inhaled beta2-agonists.
• Many anxiety disorders demonstrate a familarl pattern. First-degree biological relatives of patients with panic disorders have up to a 7-fold increased probability, as compared to the general population, of presenting with the same illness.

Workup

Laboratory Studies

The history remains the best tool available to the emergency physician in the evaluation of anxiety. Laboratory tests are rarely needed to affirm the diagnosis.

However, if there is an abnormal physical examination finding, such a goiter or prominent nystagmus, or the clinician suspects a toxic ingestion, laboratory testing can help distinguish anxiety from drug-induced causes and organic illnesses (eg, systemic infection, toxin, electrolyte and endocrine disturbances).

Imaging Studies

• Imaging studies are not useful in diagnosing anxiety but may be needed to exclude other possibilities in the differential diagnosis.

Other Tests

• Electrocardiograms are useful for evaluating possible tachydysrhythmia and screening for adverse medication effects such as QT prolongation.

Treatment

Prehospital Care

Prehospital personnel may provide reassurance and symptomatic relief within the usual protocols of EMS. Early identification of symptoms can facilitate evaluation and therapy by the emergency physician.

Emergency Department Care

• Patients with significant discomfort from their anxiety can benefit from emergency anxiolytic treatment, primarily with a benzodiazepine. In addition to ED treatment, patients in an acute anxious state of such severity that they pose a danger to themselves and or to others should have a psychiatric consultation.
• In addition to anxiolytic treatment, the clinician should be vigilant in addressing any abnormal vital signs. Patients who present with initial elevated blood pressure should have it repeated when they are less anxious. Initial tachycardia that resolves with reassurance is common. However, persistent tachycardia should not only be attributed to anxiety and organic causes (eg, dysrhythmia, pulmonary embolism, thyrotoxicosis, toxin, withdrawal, dehydration) should be considered.
• While remaining vigilant for life-threatening illness, EPs should provide a reassuring encounter to those with anxiety. Place the patient in a calm quiet room where a formal evaluation can begin to identify the functional components of the patient's anxiety. Unfortunately, such a quiet place is scarce and the ED environment often compounds the patient’s stress. Overcrowding and long wait times may also contribute to anxiety.
• In the best of circumstances, a calm environment and social support from family, friends, and the emergency staff is ideal. For patients with more severe anxiety, a short course of a fast-acting anxiolytic agent is recommended. Chronic anxiety requires a comprehensive approach and the best pharmacotherapy varies for each individual and outpatient follow up with a psychiatrist is recommended. However, these patients can be discharged on a short course of benzodiazepines until they see a psychiatrist. Patients who express suicidal or homicidal thoughts should have an emergent psychiatric evaluation in the ED.

Consultations

• Psychiatrist
• Anxiety disorders are often chronic illnesses and require follow-up psychiatric intervention for successful treatment.
• Any patient with anxiety who presents with homicidal or suicidal ideation requires urgent psychiatric intervention in the ED.

Medication

Short-acting benzodiazepines are most useful in the ED.

Barbiturates are not recommended because of their high addictive potential, marked side effects, slow onset of action, and low therapeutic indices. Tricyclic antidepressants and MAOIs should not be prescribed in the acute setting. Beta-blockers do not reduce intrinsic anxiety, although they do reduce anatomic components (eg, tachycardia, diaphoresis).

Buspirone has a low abuse potential, and a short course can safely be prescribed in the ED. However, peak efficacy may take several weeks and, in patients with concomitant depression, buspirone alone is often not effective. However, because of its excellent safety profile and low risk for abuse, it may be a preferred choice for patients that are at risk for substance abuse.

Benzodiazepines

Benzodiazepines are agents of choice due to their short half-lives and high therapeutic indices. By binding to specific receptor sites, these agents appear to potentiate the effects of GABA and facilitate inhibitory GABA neurotransmission and other inhibitory transmitters.

Lorazepam (Ativan)

Lipophilic inhibitory CNS agent that acts on GABA receptors as well as specific benzodiazepine receptors. CNS effects include sedation, anxiolysis, and striated muscle relaxation. Its IV administration has a rapid onset of action (3-5 min), and the half-life has been reported as 9-19 min.

Midazolam (Versed)

Similar to lorazepam but has shorter duration of action, approximately 1-4 h with a half-life of 2.5 h.

Serotonin receptor agonists

These agents stimulate 5-HT1-receptors, producing anxiolytic effects. Buspirone is a nonsedating antipsychotic drug unrelated to benzodiazepines, barbiturates, and other sedative-hypnotics. Has been found to be comparable with benzodiazepines in reducing symptoms of anxiety in double-blind placebo-controlled clinical trials and has fewer sedative or withdrawal adverse effects than benzodiazepines. Also has fewer cognitive and psychomotor adverse effects, which makes its use preferable in elderly patients. Major limitations include lack of antipanic activity and reduced anxiolytic effects in patients recently withdrawn from benzodiazepines. Also has a longer onset of action and, thus, is of fairly limited use as a sole agent in the treatment of acute anxiety in the ED.

Buspirone (BuSpar)

5-HT1A agonist affecting serotonergic neurotransmission in CNS. Has some dopaminergic activity as well. In addition, has demonstrated anxiolytic effect but can take up to 2-3 wk for full efficacy. Also has a low abuse potential and does not mitigate panic attacks. Not useful in benzodiazepine withdrawal but has a low adverse-effect profile.

Duloxetine (Cymbalta)

Potent inhibitor of neuronal serotonin and norepinephrine reuptake. Indicated for generalized anxiety disorder.

Follow-up

Further Inpatient Care

• All anxious patients with suicidal ideation, homicidal ideation, or acute psychosis require emergent psychiatric consultation.

Complications

• Some studies report the failure rate of diagnosing anxiety disorders at as high as 50%. This can result in overuse of health care resources and increased morbidity and mortality rates for anxiety disorders and comorbid medical conditions.

Miscellaneous

Medicolegal Pitfalls

• Anxiety states may be associated with increased prevalence of other physical illnesses.
• Avoid falsely attributing the somatic symptoms of anxiety to other medical conditions.
• Understand that anxiety can provoke or maintain other medical disorders. For example, the prevalence of hypertension has been found to be 13.6% in patients diagnosed with panic attacks compared to 4.4% in controls without panic attacks.

Knee Injury Symptoms

· ACUTE knee injuries can cause:-
- Pain
- Swelling
- Difficulty bending the knee and weightbearing

· CHRONIC knee injuries can cause:-
- Pain
- Swelling
- Minimal activity (inflammation of the joint)
- Other complaints

· PAIN
- May come and go and may not occur right away the activity but might delay as the
inflammation develops.
§ Meniscus Injury
v Pain when climbing stairs as cartilage is being pinched in the joint as it narrows with bending.
v Popping/grinding
§ Patellar Injury
v Pain when walking down the stairs as kneecap is being forced onto the femur.
§ Ligament Injury
v A feeling of instability/giving away
§ Cartilage Injury
v ‘Locking’ – knee joint refuses to completely straighten. It is due to torn piece of cartilage folds upon itself.

Anterior Cruciate Ligament (ACL) Injuries
Symptoms
Symptoms of a severe and sudden (acute) anterior cruciate ligament (ACL) injury include:

· Feeling or hearing a "pop" in the knee at the time of injury.
· Sudden instability in the knee (the knee feels wobbly, buckles or gives out) after a jump or
change in direction or after a direct blow to the side of the knee.
· Pain on the outside and back of the knee.
· Knee swelling within the first few hours of the injury. This may be a sign of bleeding inside
the joint (hemarthrosis). Swelling that occurs suddenly is usually a sign of a serious knee
injury.
· Limited knee movement because of swelling and/or pain.
· No knee pain, especially if the ACL has been completely torn and there is no tension across
the injured ligament.
· A black and blue discoloration around the knee, due to bleeding from inside the knee joint.

After an acute injury, you will almost always have to stop the activity you are engaged in but may be able to walk.

The main symptom of chronic (long-lasting and recurrent) ACL deficiency is an unstable knee joint. The knee buckles or gives out, sometimes with pain and swelling. This happens more often over time. But not everyone with an ACL injury develops a chronic ACL deficiency.
Other conditions with symptoms SIMILAR to ACL knee pain includes injuries to other knee structures, such as:
· An injury to the cartilage lining the knee joint.
· An injury to the knee cushions (menisci). About 70% of people with an ACL injury
also have a meniscus tear.
· An injury to the knee ligaments that connect the upper leg bone to the lower leg bone
along the inner side of the knee joint (medial collateral ligament) and the outer side of the
knee joint (lateral collateral ligament).
· A break (fracture) in the bones of the knee joint.