Osgood–Schlatter disease causes pain in the front lower part of the knee. This is usually at the ligament-bone junction of the patellar ligament and the tibial tuberosity. The tibial tuberosity is a slight elevation of bone on the anterior and proximal portion of the tibia. The patellar tendon attaches the anterior quadriceps muscles to the tibia via the knee cap.

Intense knee pain is usually the presenting symptom that occurs during activities such as running, jumping, squatting, and especially ascending or descending stairs and during kneeling. The pain is worse with acute knee impact. The pain can be reproduced by extending the knee against resistance, stressing the quadriceps, or striking the knee. Pain is initially mild and intermittent. In the acute phase, the pain is severe and continuous in nature. Impact of the affected area can be very painful. Bilateral symptoms are observed in 20–30% of people.

Osgood–Schlatter disease (OSD), also known as apophysitis of the tibial tubercle, is inflammation of the patellar ligament at the tibial tuberosity. It is characterized by a painful bump just below the knee that is worse with activity and better with rest. Episodes of pain typically last a few months. One or both knees may be affected and flares may recur.

Risk factors include overuse, especially sports which involve running or jumping. The underlying mechanism is repeated tension on the growth plate of the upper tibia. Diagnosis is typically based on the symptoms. A plain X-ray may be either normal or show fragmentation in the attachment area.

Pain typically resolves with time. Applying cold to the affected area, stretching, and strengthening exercises may help. NSAIDs such as ibuprofen may be used. Slightly less stressful activity may be recommended.

About 4% of people are affected at some point in time. Males between the ages of 10 and 15 are most often affected. After growth slows, typically age 16 in boys and 14 in girls, the pain will no longer occur despite a bump potentially remaining. The condition is named after Robert Bayley Osgood (1873–1956), an American orthopedic surgeon and Carl B. Schlatter, (1864–1934), a Swiss surgeon who described the condition independently in 1903.

The most common symptoms in impingement syndrome are pain, weakness and a loss of movement at the affected shoulder. The pain is often worsened by shoulder overhead movement and may occur at night, especially if the patient is lying on the affected shoulder. The onset of the pain may be acute if it is due to an injury or may be insidious if it is due to a gradual process such as an osteoarthritic spur. The pain has been described as dull rather than sharp, and lingers for long periods of a time, making it hard to fall asleep at night. Other symptoms can include a grinding or popping sensation during movement of the shoulder.

The range of motion at the shoulder may be limited by pain. A painful arc of movement may be present during forward elevation of the arm from 60° to 120°. Passive movement at the shoulder will appear painful when a downwards force is applied at the acromion but the pain will ease once the downwards force is removed.

Patients often complain of pain and swelling over the medial aspect of the knee joint. They may also report instability with side-to-side movement and during athletic performance that involves cutting or pivoting.

Patients often complain of pain and instability at the joint. With concurrent nerve injuries, patients may experience numbness, tingling and weakness of the ankle dorsiflexors and great toe extensors, or a footdrop.

Shoulder impingement syndrome, also called subacromial impingement, painful arc syndrome, supraspinatus syndrome, swimmer's shoulder, and thrower's shoulder, is a clinical syndrome which occurs when the tendons of the rotator cuff muscles become irritated and inflamed as they pass through the subacromial space, the passage beneath the acromion. This can result in pain, weakness and loss of movement at the shoulder.

Shin splints, also known as medial tibial stress syndrome (MTSS), is defined by the American Academy of Orthopaedic Surgeons as "pain along the inner edge of the shinbone (tibia)." Shin splints are usually caused by repeated trauma to the connective muscle tissue surrounding the tibia. They are a common injury affecting athletes who engage in running sports or other forms of physical activity, including running and jumping. They are characterized by general pain in the lower region of the leg between the knee and the ankle. Shin splints injuries are specifically located in the middle to lower thirds of the anterior or lateral part of the tibia, which is the larger of two bones comprising the lower leg.

Shin splints are the most prevalent lower leg injury and affect a broad range of individuals. It affects mostly runners and accounts for approximately 13% to 17% of all running-related injuries. High school age runners see shin splints injury rates of approximately 13%. Aerobic dancers have also been known to suffer from shin splints, with injury rates as high as 22%. Military personnel undergoing basic training experience shin splints injury rates between 4–8%.

Tibial plateau fractures typically presents with knee effusion, swelling of the knee soft tissues and inability to bear weight. The knee may be deformed due to displacement and/or fragmentation of the tibia which leads to loss of its normal structural appearance. Blood in the soft tissues and knee joint (hemarthrosis) may lead to bruising and a doughy feel of the knee joint. Due to the tibial plateau's proximity to important vascular (i.e. arteries, veins) and neurological (i.e. nerves such as peroneal and tibial) structures, injuries to these may occur upon fracture. A careful examination of the neurovascular systems is imperative. A serious complication of tibial plateau fractures is compartment syndrome in which swelling causes compression of the nerves and blood vessels inside the leg and may ultimately lead to necrosis or cell death of the leg tissues.

Typical symptoms include pain, refusing to walk or bear weight and limping -bruising and deformity are absent. On clinical examination, there can be warmth and swelling over the fracture area, as well as pain on bending the foot upwards (dorsiflexion). The initial radiographical images may be inconspicuous (a faint oblique line) and often even completely normal. After 1–2 weeks however, callus formation develops. The condition can be mistaken for osteomyelitis, transient synovitis or even child abuse. Contrary to CAST fractures, non-accidental injury typically affect the upper two-thirds or midshaft of the tibia.

Other possible fractures in this area, occurring in the cuboid, calcaneus, and fibula, can be associated or can be mistaken for a toddler's fracture. In some cases, an internal oblique radiography and radionuclide imaging can add information to anterior-posterior and lateral views. However, since treatment can also be initiated in the absence of abnormalities, this appears to have little value in most cases. It could be useful in special cases such as children with fever, those without a clear trauma or those in which the diagnosis remains unclear. Recently, ultrasound has been suggested as a helpful diagnostic tool.

Jacobson previously described the common problems to medial knee surgery. It was stressed that adequate diagnosis is imperative and all possible injuries should be evaluated and addressed intraoperatively. Damage to the saphenous nerve and its infrapatellar branch is possible during medial knee surgery, potentially causing numbness or pain over the medial knee and leg. As with all surgeries, there is a risk of bleeding, wound problems, deep vein thrombosis, and infection that can complicate the outcome and rehabilitation process. The long term complication of arthrofibrosis and heterotopic ossification (Pellegrini-Stieda syndrome) are problems that are best addressed with early range of motion and following defined rehabilitation protocols. Failure of graft due to intrinsic mechanical forces should be prevented with preoperative alignment assessment (osteotomy treatment) and proper rehabilitation.

The most common symptom is pain over the heel area, especially when the heel is palpated or squeezed. Patients usually have a history of recent trauma to the area or fall from a height. Other symptoms include: inability to bear weight over the involved foot, limited mobility of the foot, and limping. Upon inspection, the examiner may notice swelling, redness, and hematomas. A hematoma extending to the sole of the foot is called "Mondor Sign", and is pathognomonic for calcaneal fracture. The heel may also become widened with associated edema due to displacement of lateral calcaneal border. Involvement of soft tissue (tendons, skin, etc.,) should be evaluated because soft tissue injury has been associated to serious complications (see below).

Follow-up studies by Levy et al. and Stannard at al. both examined failure rates for posterolateral corner repairs and reconstructions. Failure rates repairs were approximately 37 – 41% while reconstructions had a failure rate of 9%.

Other less common surgical complications include deep vein thrombosis (DVTs), infection, blood loss, and nerve/artery damage. The best way to avoid these complications is to preemptively treat them. DVTs are typically treated prophylactically with either aspirin or sequential compression devices (SCDs). In high risk patients there may be a need for prophylactic administration of low molecular weight heparin (LMWH). In addition, having a patient get out of bed and ambulate soon after surgery is a time honored way to prevent DVTs. Infection is typically controlled by administering 1 gram of the antibiotic cefazolin (Ancef) prior to surgery. Excessive blood loss and nerve/artery damage are rare occurrences in surgery and can usually be avoided with proper technique and diligence; however, the patient should be warned of these potential complications, especially in patients with severe injuries and scarring.

An unhappy triad (or terrible triad, "horrible triangle", O'Donoghue's triad or a "blown knee") is an injury to the anterior cruciate ligament, medial collateral ligament, and medial meniscus. Analysis during the 1990s indicated that this 'classic' O'Donoghue triad is actually an unusual clinical entity among athletes with knee injuries. Some authors mistakenly believe that in this type of injury, acute tears of the medial meniscus always present with a concomitant lateral meniscus injury. However, the 1990 analysis showed that lateral meniscus tears are more common than medial meniscus tears in conjunction with sprains of the ACL.

Shin splint pain is described as a recurring dull ache along the inner part of the lower two-thirds of the tibia. In contrast, stress fracture pain is localized to the fracture site.

Biomechanically, over-pronation is a common factor in shin splints and action should be taken to improve the biomechanics of the gait. Pronation occurs when the medial arch moves downward and towards the body's midline to create a more stable point of contact with the ground. In other words, the ankle rolls inwards so that more of the arch has contact with the ground. This abnormal movement causes muscles to fatigue more quickly and to be unable to absorb any shock from the foot hitting the ground.

The Segond fracture is a type of avulsion fracture (soft tissue structures tearing off bits of their bony attachment) of the lateral tibial condyle of the knee, immediately beyond the surface which articulates with the femur.

Pes anserine bursitis is an inflammatory condition of the medial (inner) knee at the anserine bursa, a sub muscular bursa, just below the pes anserinus.

A tibial plateau fracture is a break of the upper part of the tibia (shinbone) that involves the knee joint. Symptoms include pain, swelling, and a decreased ability to move the knee. People are generally unable to walk. Complication may include injury to the artery or nerve, arthritis, and compartment syndrome.

The cause is typically trauma such as a fall or motor vehicle collision. Risk factors include osteoporosis and certain sports such as skiing. Diagnosis is typically suspected based on symptoms and confirmed with X-rays and a CT scan. Some fractures may not be seen on plain X-rays.

Pain may be managed with NSAIDs, opioids, and splinting. In those who are otherwise healthy, treatment is generally by surgery. Occasionally, if the bones are well aligned and the ligaments of the knee are intact, people may be treated without surgery.

They represent about 1% of broken bones. They occur most commonly in middle aged males and older females. In the 1920s they were called a "fender fracture" due to their association with people being hit by a motor vehicle while walking.

The Gosselin fracture is a V-shaped fracture of the distal tibia which extends into the ankle joint and fractures the tibial plafond into anterior and posterior fragments.

The fracture was described by Leon Athanese Gosselin, chief of surgery at the Hôpital de la Charité in Paris.

A bumper fracture is a fracture of the lateral tibial plateau caused by a forced valgus applied to the knee. This causes the lateral part of the distal femur and the lateral tibial plateau to come into contact, compressing the tibial plateau and causing the tibia to fracture. The name of the injury is because it was described as being caused by the impact of a car bumper on the lateral side of the knee while the foot is planted on the ground, although this mechanism is only seen in about 25% of tibial plateau fractures.

Fracture of the neck of the fibula may also be found, and associated injury to the medial collateral ligament or cruciate ligaments occurs in about 10% of cases.

The pes anserinus is the insertion of the conjoined tendons sartorius, gracilis, and semitendinosus into the anteromedial proximal tibia. Theoretically, bursitis results from stress to this area (e.g. stress may result when an obese individual with anatomic deformity from arthritis ascends or descends stairs). An occurrence of pes anserine bursitis commonly is characterized by pain, especially when climbing stairs, tenderness, and local swelling.

A calcaneal fracture is a break of the calcaneus (heel bone). Symptoms may include pain, bruising, trouble walking, and deformity of the heel. It may be associated with breaks of the hip or back.

It usually occurs when a person lands on their feet following a fall from a height or during a motor vehicle collision. Diagnosis is suspected based on symptoms and confirmed by X-rays or CT scaning.

If the bones remain normally aligned treatment may be by casting without weight bearing for around eights weeks. If the bones are not properly aligned surgery is generally required. Returning the bones to their normal position results in better outcomes. Surgery may be delayed a few days as long as the skin remained intact.

About 2% of all fractures are calcaneal fractures, however, they make up 60% of fractures of the mid foot bones. Undisplaced fractures may heal in around three months while more significant fractures can take two years. Difficulties such as arthritis and decreased range of motion of the foot may remain.

Stress fractures are typically discovered after a rapid increase in exercise. They most commonly present as pain with weight bearing that increases with activity. The pain usually subsides with rest but may be constantly present with a more serious bone injury. There is usually an area of localized tenderness on or near the bone and generalized swelling to the area. Percussion or palpation to the bone may reproduce symptoms. Anterior tibial stress fractures elicit focal tenderness on the anterior tibial crest, while posterior medial stress fractures can be tender at the posterior tibial border.

After a humerus fracture, pain is immediate, enduring, and exacerbated with the slightest movements. The affected region swells, with bruising appearing a day or two after the fracture. The fracture is typically accompanied by a discoloration of the skin at the site of the fracture. A crackling or rattling sound may also be present, caused by the fractured humerus pressing against itself. In cases in which the nerves are affected, then there will be a loss of control or sensation in the arm below the fracture. If the fracture affects the blood supply, then the patient will have a diminished pulse at the wrist. Displaced fractures of the humerus shaft will often cause deformity and a shortening of the length of the upper arm. Distal fractures may also cause deformity, and they typically limit the ability to flex the elbow.

In osteochondritis dissecans, fragments of cartilage or bone become loose within a joint, leading to pain and inflammation. These fragments are sometimes referred to as joint mice. OCD is a type of osteochondrosis in which a lesion has formed within the cartilage layer itself, giving rise to secondary inflammation. OCD most commonly affects the knee, although it can affect other joints such as the ankle or the elbow.

People with OCD report activity-related pain that develops gradually. Individual complaints usually consist of mechanical symptoms including pain, swelling, catching, locking, popping noises, and buckling / giving way; the primary presenting symptom may be a restriction in the range of movement. Symptoms typically present within the initial weeks of stage I; however, the onset of stage II occurs within months and offers little time for diagnosis. The disease progresses rapidly beyond stage II, as OCD lesions quickly move from stable cysts or fissures to unstable fragments. Non-specific symptoms, caused by similar injuries such as sprains and strains, can delay a definitive diagnosis.

Physical examination typically reveals fluid in the joint, tenderness, and crepitus. The tenderness may initially spread, but often reverts to a well-defined focal point as the lesion progresses. Just as OCD shares symptoms with common maladies, acute osteochondral fracture has a similar presentation with tenderness in the affected joint, but is usually associated with a fatty hemarthrosis. Although there is no significant pathologic gait or characteristic alignment abnormality associated with OCD, the patient may walk with the involved leg externally rotated in an attempt to avoid tibial spine impingement on the lateral aspect of the medial condyle of the femur.

This fracture pattern is named after Paul Jules Tillaux, a French Anatomist and Surgeon (1834-1904).