Laximetry is a reliable technique for diagnosing a torn anterior cruciate ligament.

The MRI is perhaps the most used technique for diagnosing the state of the Anterior Cruciate Ligament but it not always the most reliable. In some cases the Anterior Cruciate Ligament can indeed not be seen because of the blood surrounding it.

A study containing 100 consecutive patients with a recent anterior cruciate ligament injury were examined with respect to type of sports activity that caused the injury. Of the 100 consecutive ACL injuries, there were also 53 medial collateral ligament injuries, 12 medial, 35 lateral and 11 bicompartmental meniscal lesions. 59/100 patients were injured during contact sports, 30/100 in downhill skiing and 11/100 in other recreational activities, traffic accidents or at work.

An associated medial collateral ligament tear was more common in skiing (22/30) than during contact sports (23/59), whereas a bicompartmental meniscal lesion was found more frequently in contact sports (9/59) than in skiing (0/30). Weightbearing was reported by 56/59 of the patients with contact sports injuries whereas 8/30 of those with skiing injuries. Non-weightbearing in the injury situation led to the same rate of MCL tears (18/28) as weightbearing (35/72) but significantly more intact menisci (19/28 vs 23/72). Thus, contact sports injuries were more often sustained during weightbearing, with a resultant joint compression of both femuro-tibial compartments as shown by the higher incidence of bicompartmental meniscal lesions. The classic "unhappy triad" was a rare finding (8/100) and Fridén T, Erlandsson T, Zätterström R, Lindstrand A, and Moritz U. suggest that this entity should be replaced by the "unhappy compression injury".

Treatment of the unhappy triad usually requires surgery. An ACL surgery is common and the meniscus can be treated during the surgery as well. The MCL is rehabilitated through time and immobilization. Physical therapy after the surgery and the use of a knee brace help speed up the healing process.

A typical surgery for a blown knee includes:

- Patellar tendon autograft (An autograft is a graft that comes from the patient)

- Hamstring tendon autograft

- Quadriceps tendon autograft

- Allograft (taken from a cadaver) patellar tendon, Achilles tendon, semitendinosus, gracilis, or posterior tibialis tendon

The goal of reconstruction surgery is to prevent instability and restore the function of the torn ligament, creating a stable knee. There are certain factors that the patient must consider when deciding for or against surgery.

Elbow fractures are any broken bone around the elbow joint.

They include among others:

- Olecranon fractures

- Supracondylar humerus fractures

- Radial head fractures

The terrible triad of the elbow (not to be confused with the terrible triad of the knee) is a combination of:

- A fracture of the head of radius

- A fracture of the coronoid process of the ulna

- Humeroulnar dislocation (generally posterior or posterolateral)

The "terrible triad of the elbow" is confers joint instability and a major risk of developing osteoarthritis.

Median arcuate ligament syndrome is a diagnosis of exclusion. That is, the diagnosis of MALS is generally considered only after patients have undergone an extensive evaluation of their gastrointestinal tract including upper endoscopy, colonoscopy, and evaluation for gallbladder disease and gastroesophageal reflux disease (GERD).

The diagnosis of MALS relies on a combination of clinical features and findings on medical imaging. Clinical features include those signs and symptoms mentioned above; classically, MALS involves a triad of abdominal pain after eating, weight loss, and an abdominal bruit, although the classic triad is found in only a minority of individuals that carry a MALS diagnosis.

Diagnostic imaging for MALS is divided into screening and confirmatory tests. A reasonable screening test for patients with suspected MALS is duplex ultrasonography to measure blood flow through the celiac artery. Peak systolic velocities greater than 200 cm/s are suggestive of celiac artery stenosis associated with MALS.

Further evaluation and confirmation can be obtained via angiography to investigate the anatomy of the celiac artery. Historically, conventional angiography was used, although this has been largely replaced by less invasive techniques such as computed tomography (CT) and magnetic resonance (MR) angiography. Because it provides better visualization of intraabdominal structures, CT angiography is preferred to MR angiography in this setting. The findings of focal narrowing of the proximal celiac artery with poststenotic dilatation, indentation on the superior aspect of the celiac artery, and a hook-shaped contour of the celiac artery support a diagnosis of MALS. These imaging features are exaggerated on expiration, even in normal asymptomatic individuals without the syndrome.

Proximal celiac artery stenosis with poststenotic dilatation can be seen in other conditions affecting the celiac artery. The hook-shaped contour of the celiac artery is characteristic of the anatomy in MALS and helps distinguish it from other causes of celiac artery stenosis such as atherosclerosis. This hooked contour is not entirely specific for MALS however, given that 10-24% of normal asymptomatic individuals have this anatomy.

Diagnosis can be difficult as symptoms may be nonspecific. A CT scan of the head is typically recommended if a concern is present. While retinal bleeding is common, it can also occur in other conditions.

There are few studies of the long-term outcomes of patients treated for MALS. According to Duncan, the largest and more relevant late outcomes data come from a study of 51 patients who underwent open surgical treatment for MALS, 44 of whom were available for long-term follow-up at an average of nine years following therapy. The investigators reported that among patients who underwent celiac artery decompression and revascularization, 75% remained asymptomatic at follow-up. In this study, predictors of favorable outcome included:

- Age from 40 to 60 years

- Lack of psychiatric condition or alcohol use

- Abdominal pain that was worse after meals

- Weight loss greater than 20 lb (9.1 kg)

While the findings of AHT are complex and many, they are often referred to as a "triad". The process of inferring violent or abusive shaking from the findings in the SBS diagnosis has also been referred to as a hypothesis.

In 2000, Rob Parish, Deputy Director of the National Center on Shaken Baby Syndrome, summarized the "triad" as follows: "Often referred to as the “triad”, the consensus continues to be that a collection of (1)damage to the brain, evidenced by severe brain swelling and/or diffuse traumatic axonal injury; (2) bleeding under the membranes which cover the brain, usually subdural and/or subarachnoid bleeding; and, (3) bleeding in the layers of the retina, often accompanied by other ocular damage, when seen in young children or infants, is virtually diagnostic of severe, whiplash shaking of the head."

SBS may be misdiagnosed, underdiagnosed, and overdiagnosed, and caregivers may lie or be unaware of the mechanism of injury. Commonly, there are no externally visible signs of the condition. Examination by an experienced ophthalmologist is often critical in diagnosing shaken baby syndrome, as particular forms of ocular bleeding are quite characteristic. Magnetic resonance imaging may also depict retinal bleeds; this may occasionally be useful if an ophthalmologist examination is delayed or unavailable. Conditions that must be ruled out include hydrocephalus, sudden infant death syndrome (SIDS), seizure disorders, and infectious or congenital diseases like meningitis and metabolic disorders. CT scanning and magnetic resonance imaging are used to diagnose the condition. Conditions that may accompany SBS include bone fractures, injury to the cervical spine (in the neck), retinal bleeding, cerebral bleed or atrophy, hydrocephalus, and papilledema (swelling of the optic disc).

The terms "non-accidental head injury" or "inflicted traumatic brain injury" have been suggested instead of "SBS".

The connection of the triad to episodes of traumatic shaking is controversial with a 2016 systematic review finding limited scientific evidence associating the triad to episodes of traumatic shaking, and insufficient evidence for using the triad to identify such episodes. The connection is controversial in part following cases where parents of children exhibiting the triad have, in addition to losing custody, been jailed or sentenced to death.

There are two types of normal pressure hydrocephalus: idiopathic and secondary. The secondary type of NPH can be due to a subarachnoid hemorrhage, head trauma, tumor, infection in the central nervous system, or a complication of cranial surgery.

Diagnosis of NPH is usually first led by brain imaging, either CT or MRI, to rule out any mass lesions in the brain. This is then followed by lumbar puncture and evaluation of clinical response to removal of CSF. This can be followed by continuous external lumbar CSF drainage during 3 or 4 days.

- CT scan may show enlarged ventricles without convolutional atrophy.

- MRI may show some degree of transependymal migration of CSF surrounding the ventricles on T2/FLAIR sequence. Imaging however cannot differentiate between pathologies with similar clinical picture like Alzheimer's dementia, vascular dementia or Parkinson's disease.

- Following imaging, lumbar puncture is usually the first step in diagnosis and the CSF opening pressure is measured carefully. In most cases, CSF pressure is usually above 155 mmHO. Clinical improvement after removal of CSF (30 mL or more) has a high predictive value for subsequent success with shunting. This is called the "lumbar tap test" or Miller Fisher test. On the contrary, a "negative" test has a very low predictive accuracy, as many patients may improve after a shunt in spite of lack of improvement after CSF removal.

- Infusion test is a test that may have higher sensitivity and specificity than a lumbar puncture, but is not performed in most centers. The outflow conductance (Cout) of the cerebrospinal fluid (CSF) system is a parameter considered by some centers to be predictive in selection for hydrocephalus surgery. Cout can be determined through an infusion test. This is not a test that is normally performed prior to shunting, but may become more accepted.

- In some centers, External lumbar drainage has been shown to have the highest sensitivity and specificity with regards to predicting a successful outcome following surgery.

Treatment involves revascularization typically using either angioplasty or a type of vascular bypass

- Kissing balloon angioplasty +/- stent, so named because the two common iliac stents touch each other in the distal aorta.

- Aorto-iliac bypass graft

- Axillary-bi-femoral and femoral-femoral bypass (sometimes abbreviated "ax-fem fem-fem")

Although there are no definitive criteria to diagnose the existence of reactive arthritis, the American College of Rheumatology has published sensitivity and specificity guidelines.

There are few clinical symptoms, but the clinical picture is dominated by arthritis in one or more joints, resulting in pain, swelling, redness, and heat sensation in the affected areas.

The urethra, cervix and the throat may be swabbed in an attempt to culture the causative organisms. Cultures may also be carried out on urine and stool samples or on fluid obtained by arthrocentesis.

Tests for C-reactive protein and erythrocyte sedimentation rate are non-specific tests that can be done to corroborate the diagnosis of the syndrome.

A blood test for the genetic marker HLA-B27 may also be performed. About 75 percent of all the patients with Reiter's arthritis have this gene.

In medicine, aortoiliac occlusive disease, also known as Leriche's syndrome and Leriche syndrome, is a form of central artery disease involving the blockage of the abdominal aorta as it transitions into the common iliac arteries.

NSAIDs (non steroid anti-inflammatory drug) are the usual recommended treatment for Löfgren syndrome.

Gradenigo's syndrome, also called Gradenigo-Lannois syndrome and petrous apicitis, is a complication of otitis media and mastoiditis involving the apex of the petrous temporal bone. It was first described by Giuseppe Gradenigo in 1904 when he reported a triad of symptoms consisting of: (1)"unilateral periorbital pain" related to trigeminal nerve involvement, (2)"diplopia" due to sixth nerve palsy and (3)persistent "otorrhea", associated with bacterial otitis media with apex involvement of the petrous part of the temporal bone (petrositis). The classical syndrome related to otitis media has become very rare after the antibiotic era.

Löfgren syndrome is associated with a good prognosis, with > 90% of patients experiencing disease resolution within 2 years. In contrast, patients with the disfiguring skin condition lupus pernio or cardiac or neurologic involvement rarely experience disease remission.

The type of treatment, like that of most disorders, depends on the severity of the symptoms. One option is to perform a "vesicostomy", which allows the bladder to drain through a small hole in the abdomen, thus helping to prevent urinary tract infections. Similarly, consistent self catheterization, often several times per day, can be an effective approach to preventing infections. A more drastic procedure is a surgical "remodeling" of the abdominal wall and urinary tract. Boys often need to undergo an orchiopexy, to move the testes to their proper place in the scrotum.

Other symptoms of the syndrome include:

- retroorbital pain due to pain in the area supplied by the ophthalmic branch of the trigeminal nerve (fifth cranial nerve),

- abducens nerve palsy (sixth cranial nerve), and

- otitis media.

Other symptoms can include photophobia, excessive lacrimation, fever, and reduced corneal sensitivity.

The syndrome is usually caused by the spread of an infection into the petrous apex of the temporal bone.

MRI will help with the diagnosis of structural abnormality of the brain. Genetic testing may also be pursued.

The prevalence of LVT with AMI is 5-15%. The rates of AMI associated with LVT is declining due to the use of better therapies and percutaneous coronary intervention used to treat myocardial infarction. LVT formation has been found to be higher in anterior wall AMI than other types of AMI.

Echocardiography is the main diagnostic tool for LVT. A distinct mass is visible in the left ventricle. Computed Tomography and Magnetic Resonance Imaging are effective, but less common ways to detect LVT, due to their costs and risks. It is possible to assess whether a thrombus will become an embolus through echocardiography. Mobility and protrusion of the thrombus are two characteristics associated with increased embolic potential.

Meltzer’s triad describes the classical symptoms suggesting the diagnosis of cryoglobulinaemia of polyclonal CGs seen in essential-, viral-, or connective tissue disease-associated cryoglobulinaemia. The triad consists of:

- palpable purpura

- arthralgia (joint pain)

- weakness.

On chest radiography, a retrocardiac, gas-filled viscus may be seen in cases of intrathoracic stomach, which confirms the diagnosis. Plain abdominal radiography reveals a massively distended viscus in the upper abdomen. In organoaxial volvulus, plain films may show a horizontally oriented stomach with a single air-fluid level and a paucity of distal gas. In mesenteroaxial volvulus, plain abdominal radiographic findings include a spherical stomach on supine images and 2 air-fluid levels on erect images, with the antrum positioned superior to the fundus.

- Upper GI contrast studies:

The diagnosis of gastric volvulus is usually based on barium studies; however, some authors recommend computed tomography (CT) scanning as the imaging modality of choice.

Upper gastrointestinal (GI) contrast radiographic studies (using barium or Gastrografin) are sensitive and specific if performed with the stomach in the "twisted" state and may show an upside-down stomach. Contrast studies have been reported to have a diagnostic yield in 81–84% of patients.

Often performed for an evaluation of acute abdominal pain, a computed tomography (CT) scan can offer immediate diagnosis by showing two bubbles with a transition line. Proponents of CT scanning in the diagnosis of gastric volvulus report several benefits, including:

1. the ability to rapidly diagnose the condition based on a few coronal reconstructed images,

2. the ability to detect the presence or absence of gastric pneumatosis and free air,

3. the detection of predisposing factors (i.e., diaphragmatic or hiatal hernias), and

4. the exclusion of other abdominal pathology.

- Endoscopy:

Upper gastrointestinal (GI) endoscopy may be helpful in the diagnosis of gastric volvulus. When this procedure reveals distortion of the gastric anatomy with difficulty intubating the stomach or pylorus, it can be highly suggestive of gastric volvulus. In the late stage of gastric volvulus, strangulation of the blood supply can result in progressive ischemic ulceration or mucosal fissuring.

The nonoperative mortality rate for gastric volvulus is reportedly as high as 80%. Historically, mortality rates of 30–50% have been reported for acute gastric volvulus, with the major cause of death being strangulation, which can lead to necrosis and perforation. With advances in diagnosis and management, the mortality rate from acute gastric volvulus is 15–20% and that for chronic gastric volvulus is 0–13%.