According to the posterior cruciate ligament injuries only account for 1.5 percent of all knee injuries (figure 2). If it is a single injury to the posterior cruciate ligament that requires surgery only accounted for 1.1 percent compared to all other cruciate surgeries but when there was multiple injuries to the knee the posterior cruciate ligament accounted for 1.2 percent of injuries.

Knee injuries are very common among athletes as well as regular active people and can always be prevented. Ligament tears account for more than forty percent of knee injuries and the posterior cruciate ligament is considered one of the less common injuries. Although it is less common, there are still important measures that can be taken in order to prevent this type of knee injury. Maintaining proper exercise and sport technique is crucial for injury prevention, which include not exceeding the body or not going over the proper range of motion of the knee, properly warming up and cooling down

It is possible to prevent the onset of prepatellar bursitis, or prevent the symptoms from worsening, by avoiding trauma to the knee or frequent kneeling. Protective knee pads can also help prevent prepatellar bursitis for those whose professions require frequent kneeling and for athletes who play contact sports, such as American football, basketball, and wrestling.

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.

An effective rehabilitation program reduces the chances of reinjury and of other knee-related problems such as patellofemoral pain syndrome and osteoarthritis. Rehabilitation focuses on maintaining strength and range of motion to reduce pain and maintain the health of the muscles and tissues around the knee joint.

Tear of a meniscus is a common injury in many sports. The menisci hold 30–50% of the body load in standing position. Some sports where a meniscus tear is common are American football, association football, ice hockey and tennis. Regardless of what the activity is, it is important to take the correct precautions to prevent a meniscus tear from happening.

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".

One of the main ways to prevent OSD is to check the participant's flexibility in their quadriceps and hamstrings. Lack of flexibility in these muscles can be direct risk indicator for OSD. Muscles can shorten, which can cause pain but this is not permanent. Stretches can help reduce shortening of the muscles. The main stretches for prevention of OSD focus on the hamstrings and quadriceps.

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.

Two types of treatment options are typically available:

- Surgery

- Conservative treatment (rehabilitation and physical therapy)

Surgery may impede normal growth of structures in the knee, so doctors generally do not recommend knee operations for young people who are still growing. There are also risks of complications, such as an adverse reaction to anesthesia or an infection.

When designing a rehabilitation program, clinicians consider associated injuries such as chipped bones or soft tissue tears. Clinicians take into account the person's age, activity level, and time needed to return to work and/or athletics. Doctors generally only recommend surgery when other structures in the knee have sustained severe damage, or specifically when there is:

- Concurrent osteochondral injury

- Continued gross instability

- Palpable disruption of the medial patellofemoral ligament and the vastus medialis obliquus

- High-level athletic demands coupled with mechanical risk factors and an initial injury mechanism not related to contact

Supplements like glucosamine and NSAIDs can be used to minimize bothersome symptoms.

The condition is usually self-limiting and is caused by stress on the patellar tendon that attaches the quadriceps muscle at the front of the thigh to the tibial tuberosity. Following an adolescent growth spurt, repeated stress from contraction of the quadriceps is transmitted through the patellar tendon to the immature tibial tuberosity. This can cause multiple subacute avulsion fractures along with inflammation of the tendon, leading to excess bone growth in the tuberosity and producing a visible lump which can be very painful, especially when hit. Activities such as kneeling may also irritate the tendon.

The syndrome may develop without trauma or other apparent cause; however, some studies report up to 50% of patients relate a history of precipitating trauma. Several authors have tried to identify the actual underlying etiology and risk factors that predispose Osgood–Schlatter disease and postulated various theories. However, currently it is widely accepted that Osgood–Schlatter disease is a traction apophysitis of the proximal tibial tubercle at the insertion of the patellar tendon caused by repetitive micro-trauma. In other

words, Osgood–Schlatter disease is an overuse injury and closely related to the physical activity of the child. It was shown that children

who actively participate in sports are affected more frequently as compared with non-participants. In a retrospective study of adolescents, old athletes actively participating in sports showed a frequency of 21% reporting the syndrome compared with only 4.5% of age-matched nonathletic controls.

The symptoms usually resolve with treatment but may recur for 12–24 months before complete resolution at skeletal maturity, when the tibial epiphysis fuses. In some cases the symptoms do not resolve until the patient is fully grown. In approximately 10% of patients the symptoms continue unabated into adulthood, despite all conservative measures.

Risk factors for developing shin splints include:

- Excessive pronation at subtalar joint

- Excessively tight calf muscles (which can cause excessive pronation)

- Engaging the medial shin muscle in excessive amounts of eccentric muscle activity

- Undertaking high-impact exercises on hard, noncompliant surfaces (ex: running on asphalt or concrete)

- Smoking and low fitness level

While medial tibial stress syndrome is the most common form of shin splints, compartment syndrome and stress fractures are also common forms of shin splints. Females are 1.5 to 3.5 times more likely to progress to stress fractures from shin splints. This is due in part to females having a higher incidence of diminished bone density and osteoporosis.

Future research with regard to medial knee injuries should evaluate clinical outcomes between different reconstruction techniques. Determining the advantages and disadvantages of these techniques would also be beneficial for optimizing treatment.

There are three major ways of preventing a meniscus tear. The first of these is wearing the correct footwear for the sport and surface that the activity is taking place on. This means that if the sport being played is association football, cleats are an important item in reducing the risk of a meniscus tear. The proper footwear is imperative when engaging in physical activity because one off-balanced step could mean a meniscus tear.

It is highly advised that cleats contain a sole that molds around the foot, no less than fourteen cleats per shoe, no lower than a half inch diameter of the cleat tip, and at most, a three-eighths inch of cleat length.

Typical treatments include rest, ice, strengthening and gradually returning to activity. Rest and ice work to allow the tibia to recover from sudden, high levels of stress and reduce inflammation and pain levels. It is important to significantly reduce any pain or swelling before returning to activity. Strengthening exercises should be performed after pain has subsided, on lower leg and hip muscles. Individuals should gradually return to activity, beginning with a short and low intensity level. Over multiple weeks, they can slowly work up to normal activity level. It is important to decrease activity level if any pain returns. Individuals should consider running on other surfaces besides asphalt, such as grass, to decrease the amount of force the lower leg must absorb. Orthoses and insoles help to offset biomechanical irregularities, like pronation, and help to support the arch of the foot. Other conservative interventions include footwear refitting, orthotics, manual therapy, balance training (e.g. using a balance board), cortisone injections, and calcium and vitamin D supplementation.

Less common forms of treatment for more severe cases of shin splints include extracorporeal shockwave therapy (ESWT) and surgery. Surgery is only performed in extreme cases where more conservative options have been tried for at least a year. However, surgery does not guarantee 100% recovery.

Non-septic prepatellar bursitis can be treated with rest, the application of ice to the affected area, and anti-inflammatory drugs, particularly ibuprofen. Elevation of the affected leg during rest may also expedite the recovery process. Severe cases may require fine-needle aspiration of the bursa fluid, sometimes coupled with cortisone injections. However, some studies have shown that steroid injections may not be an effective treatment option. After the bursitis has been treated, rehabilitative exercise may help improve joint mechanics and reduce chronic pain.

Opinions vary as to which treatment options are most effective for septic prepatellar bursitis. McAfee and Smith recommend a course of oral antibiotics, usually oxacillin sodium or cephradine, and assert that surgery and drainage are unnecessary. Wilson-MacDonald argues that oral antibiotics are "inadequate", and recommends intravenous antibiotics for managing the infection. Some authors suggest surgical irrigation of the bursa by means of a subcutaneous tube. Others suggest that bursectomy may be necessary for intractable cases; the operation is an outpatient procedure that can be performed in less than half an hour.

A study by Geeslin and LaPrade indicated that patients reported positive outcomes in 94% of cases following a mix of repairs and reconstructions for with acute posterolateral knee injuries. Recent studies have reported failure rates between 37 and 40% for primary repairs of the main PLC structures Studies have shown that patients who undergo successful surgical repair of posterolateral knee injuries reported increased objective knee stability and better subjective outcomes than those who undergo reconstruction. A study by LaPrade "et al." showed that patients with isolated or combined PLC injuries have positive outcomes when they undergo anatomic reconstruction of the damaged structures, and there was no difference between groups that require an osteotomy versus those who do not. Patients reported significant increases in both knee stability and function following reconstruction. Anatomic techniques aim to restore normal function of the knee’s important static stabilizers and are recommended for patients with these types of injuries to provide the best outcomes.

As with any body part, maintaining strength and flexibility of the muscles can help to prevent injuries. Specifically in the knee, the quadriceps and hamstring muscles help to stabilize the knee, and maintaining their strength and flexibility will help prevent minor stresses from developing into major injuries. Proper footwear can also help prevent injuries. Wearing shoes that are appropriate for the activity help decrease the risk of slipping or twisting forces acting on the knee. In some circumstances, prophylactic bracing or taping may reduce the risk of injury as well.

If the fracture is small, it is usually sufficient to treat with rest and support bandage, but in more severe cases, surgery may be required. Ice may be used to relieve swelling.

Displaced avulsion fractures are best managed by either open reduction and internal fixation or closed reduction and pinning. Open reduction (using surgical incision) and internal fixation is used when pins, screws, or similar hardware is needed to fix the bone fragment.

Treatment of medial knee injuries varies depending on location and classification of the injuries. The consensus of many studies is that isolated grade I, II, and III injuries are usually well suited to non-operative treatment protocols. Acute grade III injuries with concomitant multiligament injuries or knee dislocation involving medial side injury should undergo surgical treatment. Chronic grade III injuries should also undergo surgical treatment if the patient is experiencing rotational instability or side-to-side instability.

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.

Bone mineral density decreases with increasing age. Osteoporotic bone loss can be prevented through an adequate intake of vitamin C and vitamin D, coupled with exercise and by being a non-smoker. A study by Cheng et al. in 1997, showed that greater bone density indicated less risk for fractures in the calcaneus.

Boxers and other combat athletes routinely use hand wraps and boxing gloves to help stabilize the hand, greatly reducing pain and risk of injury during impact. Proper punching form is the most important factor to prevent this type of fracture.

Treatment involves pain medication and immobilization at first; later, physical therapy is used. Ice over the affected area may increase comfort. Movement exercises are begun within at least a week of the injury; with these, fractures with little or no displacement heal without problems. Over 90% of scapular fractures are not significantly displaced; therefore, most of these fractures are best managed without surgery. Fractures of the scapular body with displacement may heal with malunion, but even this may not interfere with movement of the affected shoulder. However, displaced fractures in the scapular processes or in the glenoid do interfere with movement in the affected shoulder if they are not realigned properly. Therefore, while most scapular fractures are managed without surgery, surgical reduction is required for fractures in the neck or glenoid; otherwise motion of the shoulder may be impaired.

The climbers most prone to injuries are intermediate to expert within lead climbing or bouldering.