Women in sports such as association football, basketball, and tennis are significantly more prone to ACL injuries than men. The discrepancy has been attributed to gender differences in anatomy, general muscular strength, reaction time of muscle contraction and coordination, and training techniques.

Gender differences in ACL injury rates become evident when specific sports are compared. A review of NCAA data has found relative rates of injury per 1000 athlete exposures as follows:

- Men's basketball 0.07, women's basketball 0.23

- Men's lacrosse 0.12, women's lacrosse 0.17

- Men's football 0.09, women's football 0.28

The highest rate of ACL injury in women occurred in gymnastics, with a rate of injury per 1000 athlete exposures of 0.33

Of the four sports with the highest ACL injury rates, three were women's – gymnastics, basketball and soccer.

According to recent studies, female athletes are two to eight times more likely to strain their anterior cruciate ligament (ACL) in sports that involve cutting and jumping as compared to men who play the same particular sports (soccer, basketball, and volleyball). Differences between males and females identified as potential causes are the active muscular protection of the knee joint, the greater Q angle putting more medial torque on the knee joint, relative ligament laxity caused by differences in hormonal activity from estrogen and relaxin, intercondylar notch dimensions, and muscular strength.

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".

High school athletes are at increased risk for ACL tears when compared to non-athletes. This risk increases with certain types of sports. Among high school girls, the sport with the highest risk of ACL tear is soccer, followed by basketball and lacrosse. The highest risk sport for boys was basketball, followed by lacrosse and soccer. Children and young athletes may benefit from early surgical reconstruction after ACL injury. Young athletes who have early surgical reconstruction of their torn ACL are more likely to return to their previous level of athletic ability when compared to those who underwent delayed surgery or nonoperative treatment. They are also less likely to experience instability in their knee if they undergo early surgery.

In 1936, Cambell stated that an "impairment of the anterior crucial and medial ligaments is associated with injuries of the internal cartilage". In 1950, O'Donoghue described the unhappy triad as: (1) rupture of the medial collateral ligament, (2) damage to the medial meniscus and (3) rupture of the anterior cruciate ligament. O'Donoghue estimated the incidence rate in the traumatic sports knee to be 25%.

In 1991, Shelbourne and Nitz questioned the validity of O'Donoghue's terrible triad study. A review of all arthroscopically confirmed acute injuries of second degree or worse to the ACL and MCL was performed. Of the 52 knees reviewed, 80% of group 1 had lateral meniscus tears and 29% had associated medial meniscus tears. None of the medial meniscus tears were isolated; medial meniscus tears were not present in the absence of a lateral meniscus tear. From this study, it was concluded that the structures more typically involved in a triad were the anterior cruciate ligament, medial collateral ligament, and the lateral (not medial) meniscus.

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.

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)

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")

Decompression of the celiac artery is the general approach to treatment of MALS. The mainstay of treatment involves an open surgical approach to divide, or separate, the median arcuate ligament to relieve the compression of the celiac artery. This is combined with removal of the celiac ganglia and evaluation of blood flow through the celiac artery, for example by intraoperative duplex ultrasound. If blood flow is poor, celiac artery revascularization is usually attempted; methods of revascularization include aortoceliac bypass, patch angioplasty, and others.

A laparoscopic approach may also be used to achieve celiac artery decompression; however, should the celiac artery require revascularization, the procedure would require conversion to an open approach.

Endovascular methods such as percutaneous transluminal angioplasty (PTA) have been used in patients who have failed open and/or laparoscopic intervention. PTA alone, without decompression of the celiac artery, may not be of benefit.

Abusive head trauma (AHT), commonly known as shaken baby syndrome (SBS), is an injury to a child's head caused by someone else. Symptoms may range from subtle to obvious. Symptoms may include vomiting or a baby that will not settle. Often there are no visible signs of trauma. Complications include seizures, visual impairment, cerebral palsy, and cognitive impairment.

The cause may be blunt trauma or vigorous shaking. Often this occurs as a result of a caregiver becoming frustrated due to the child crying. 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. Abusive head trauma is a type of child abuse.

Educating new parents appears to be beneficial in decreasing rates of the condition. Treatment occasionally requires surgery, such as to place a cerebral shunt. AHT is estimated to occur in 3 to 4 per 10,000 babies a year. It occurs most frequently in those less than five years of age. The risk of death is about 25%. The diagnosis may also carry legal consequences for the parents.

Interventions by neonatal nurses including giving parents information about abusive head trauma, normal infant crying and reasons for crying, teaching how to calm an infant, and how to cope if the infant was inconsolable may reduce rates of AHT.

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

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.

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.

Patients with dementia who are confined to a nursing home and may have undiagnosed NPH can possibly become independent again once treated. So far only one study was able to evaluate the prevalence of NPH, both diagnosed and undiagnosed, among residents of assisted-living facilities, showing a prevalence in 9 to 14% of the residents.

NPH may be relieved by surgically implanting a ventriculoperitoneal shunt to drain excess cerebrospinal fluid to the abdomen where it is absorbed. Once the shunt is in place, the ventricles usually diminish in size in 3 to 4 days, regardless of the duration of the hydrocephalus. Even though the ventricular swelling diminishes, only 21% of patients show a marked improvement in symptoms. The most likely patients to show improvement are those that show only gait disturbance, mild or no incontinence, and mild dementia. A more recent study (2004) found better outcomes, concluding that if patients with idiopathic normal pressure hydrocephalus are correctly identified, shunt insertion yielded beneficial outcomes in 86% of patients, in either gait disturbance (81%), improved continence (70%), or both. They also observed that measurements in the diagnostic clinical triad, the cortical sulci size, and periventricular lucencies were related to outcome. However, other factors such as age of the patient, symptom duration, dilation of ventricles, and the degree of presurgical dementia were unrelated to outcome.

Löfgren syndrome is a type of acute sarcoidosis that is frequent in Scandinavian, Irish, African and Puerto Rican women. It was described in 1953 by Sven Halvar Löfgren, a Swedish clinician. Some have considered the condition to be imprecisely defined.

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.

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.

The main goal of treatment is to identify and eradicate the underlying infectious source with the appropriate antibiotics if still present. Otherwise, treatment is symptomatic for each problem. Nonspecific urethritis may be treated with a short course of tetracycline. Analgesics, particularly NSAIDs, are used. Steroids, sulfasalazine and immunosuppressants may be needed for patients with severe reactive symptoms that do not respond to any other treatment. Local corticosteroids are useful in the case of iritis.

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.

The Currarino syndrome (also Currarino triad) is an inherited congenital disorder where either the sacrum (the fused vertebrae forming the back of the pelvis) is not formed properly, or there is a mass in the presacral space in front of the sacrum, and (3) there are malformations of the anus or rectum. It can also cause an anterior meningocele or a presacral teratoma.

Presacral teratoma usually is considered to be a variant of sacrococcygeal teratoma. However, the presacral teratoma that is characteristic of the Currarino syndrome may be a distinct kind.

The disorder is an autosomal dominant genetic trait caused by a mutation in the HLXB9 homeobox gene. In 2000 the first large series of Currarino cases was genetically screened for HLXB9 mutations, and it was shown that the gene is specifically causative for the syndrome, but not for other forms of sacral agenesis. The study was published on the American Journal of Human Genetics.

Reactive arthritis may be self-limiting, frequently recurring, chronic or progressive. Most patients have severe symptoms lasting a few weeks to six months. 15 to 50 percent of cases involve recurrent bouts of arthritis. Chronic arthritis or sacroiliitis occurs in 15–30 percent of cases. Repeated attacks over many years are common, and patients sometimes end up with chronic and disabling arthritis, heart disease, amyloid deposits, ankylosing spondylitis, immunoglobulin A nephropathy, cardiac conduction abnormalities, or aortitis with aortic regurgitation. However, most people with reactive arthritis can expect to live normal life spans and maintain a near-normal lifestyle with modest adaptations to protect the involved organs.

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.

Wildervanck syndrome or cervico-oculo-acoustic syndrome comprises a triad of:

- Duane syndrome

- Klippel-Feil anomaly (fused cervical vertebrae)

- congenital hearing loss

There are also surgical procedures for removal of a thrombus (thrombectomy).