Dr. Martin's notes

Tuesday Feb 28, 2017

Knee Injuries

Injuries to the knee can be either traumatic or overuse injuries. Recognizing which mechanism of injury is at fault will assist the certified athletic trainer in making correct assessments and directing appropriate interventions

Patellofemoral Problems
The patellofemoral joint is composed of the articulation of the patella with the femur. The patella is shaped like a triangle with its apex directed inferiorly. The classic complaint with a patellofemoral problem is aching pain in the front of the knee. More often than not, it is of gradual onset. Some athletes may complain of a grinding noise, known as crepitus. This may be a concern to the athlete, but it is generally a benign condition.

The patella should slide or track in the center of the trochlear groove as the knee bends and extends. When the structures around the patella are out of balance, lateral tracking of the patella can occur. Palpation of the space between the undersurface of the medial and lateral borders of the patella and the femur can indicate if a patella is tilting.

An athlete who pronates may need support with a shoe insert to support the arch, or low-dye taping. The athlete with a lateral-tracking patella may also be helped by a brace designed to resist this condition.

Patellar Tendonitis
Sports that require fast running and abrupt changes of direction also place high forces on the patellar tendon. This high-force, repetitive strain frequently causes tendonitis of the patellar tendon. Inflammation of the patellar tendon is often seen in sports that involve jumping. In fact, this condition is often referred to as jumper's knee. Activity modification should be considered to allow the tendon time to heal. Nonimpact activities such as cycling and swimming will allow the patellar tendon to heal. Ice application soon after exercise will help keep inflammation from activity in check.

Fat Pad Syndrome
A painful condition in the infrapatellar region (area just below the patella) is fat pad syndrome. The infrapatellar fat pad (also known as Hoffa's fat pad) is a region of fatty tissue lying deep under the patellar tendon. This structure can become inflamed and painful. Strengthening exercises that avoid full knee extension, or leg presses that avoid full knee extension, may be tolerated well.

Medial Collateral Ligament (MCL) Sprain
A blow to the outside of the knee, as in a football tackle, or a high-energy twisting maneuver are common causes of MCL injuries. These forces result in stretching and a vaigus (outward) force on the medial tibiofemoral joint, which can damage this ligament. Pain and tenderness are felt on the medial aspect of the knee. Acute injuries should be treated with RICE (rest, ice, compression, and elevation). Protection may come from a protective wrap, brace, or crutches. The valgus stress test checks for MCL stability

Lateral Collateral Ligament (LCL) Sprain
The LCL is on the lateral side of the knee and is not frequently involved in sports injuries. It can be injured by a blow to the medial side of the knee, resulting in a varus (inside) stress to the knee joint. Treatment of LCL sprains is similar to that for MCL sprains (see preceding sections). The varus stress test checks for stability in the LCL

Torn Anterior Cruciate Ligament

The incident of ACL injuries has since shifted, so that now more ACL tears are diagnosed in female than male athletes. Research has shown that females who participate in basketball and soccer are four to six times more likely to sustain an injury to the ACL than males who play the same sport. Orthopedic researchers reported that the following factors help to explain the increase:

Biomechanical factors
Hormonal influences
Environmental factors
Anatomic risk factors

Situations that place a loaded knee joint in a combined position of flexion, valgus, and rotation of the tibia on the femur, can rupture the ACL in a noncontact manner. An example is a basketball player making a rapid change of direction, or a falling skier could suffer this type of injury. Once an ACL is stretched or ruptured, it will not heal. ACL injuries are sometimes accompanied by meniscus tears and MCL sprains.

A classic sign of an ACL injury is the athlete complaining that she heard or felt a "pop," followed by rapid effusion (swelling within the joint cavity). Some athletes may attempt to stand after rupture, only to have the knee buckle. The athlete may feel nauseated for a few minutes after the injury. Ligament integrity can be assessed with the Lachman's maneuver or anterior drawer test. Acute care should include splinting, icing, and compressive wrapping. The athlete will need crutches. All athletes with suspected ACL tears should be referred to their family physicians for definitive diagnosis.

Posterior Cruciate Ligament Tear
The most common cause of PCL injuries is athletic, motor vehicle, or industrial accidents. Most athletic PCL injuries occur during a fall on the flexed (bent) knee with the foot plantar flexed (the toes pointing down with the top of the foot in line with the front of the leg). The tibia strikes the ground first and is pushed backward. A positive "sag test" is diagnostic of a PCL tear. The sag test is conducted with the athlete lying in the supine position, with the knee bent at 90 degrees. The knee should not have the appearance of bending (sagging) backwards.
Immediate care uses the PRICE approach. Suspected PCL tears should be assessed by the athlete's physician. Physical therapy and a strong rehabilitation program aimed at strength restoration and proprioception enhancement are important for PCL injuries.

Meniscus Tears
The medial meniscus is attached to the ligaments on the back and medial side of the knee. Because it is attached so securely, it does not move freely. This causes it to be torn more often than the lateral meniscus, which is on the outside half of the joint. The lateral meniscus is attached only at the back of the knee and moves more freely as the knee is bent and straightened.

The menisci can be torn when the knee is twisted suddenly and one or both menisci become trapped between the femur and tibia. They can also be torn when the ligaments in and around the knee are torn. Symptoms of a torn meniscus may include pain, popping, locking, or giving way of the knee. The tibiofemoral joint spaces may be tender. Immediate care should include ice and compressive wrap. If the athlete cannot walk with stability, crutches may be needed.

Epiphyseal (Growth-Plate) Injuries
The knee is subject to sports-induced trauma at the centers of bone growth in skeletally immature athletes. The growth plates at the end of long bones, called epiphyseal plates, are at risk from direct trauma. Because this type of injury can be quite serious in a growing athlete, return to play should be permitted only with a physician's approval.

Osgood-Schlatter Condition
Osgood-Schlatter condition is a group of symptoms involving the tibial tubercle epiphysis. Traction of the quadriceps muscle may cause disruption and inflammation in the layers of the tubercle. In other words, if the femur is growing faster than the quadriceps muscle, the quadriceps will exert undue pressure on the growth center of the tibia (where the patellar tendon attaches), causing pai. Signs and symptoms of Osgood-Schlatter condition include:

Pain over the tibial tubercle
Swelling over the tibial tubercle
Weakness in the quadriceps muscle group
Increased pain and swelling with activity
Visible lump
Pain to the touch over the affected area

Preventing this problem from progressing to a season-ending injury is fairly easy. The three symptoms to address are pain, swelling, and flexibility.

Iliotibial Band Syndrome
Iliotibial band syndrome occurs when there is inflammation of the iliotibial band (a thick band of fibrous tissue that runs down the outside of the leg). However, when inflamed, the iliotibial band does not glide easily, and pain associated with movement results. Proper footwear, icing the area of pain, and stretching will help treat iliotibial band syndrome. Modifying the athlete's training program, as well as cross-training, will be helpful. The athlete will need to reduce his or her activity level until symptoms subside.

A fracture of the patella is usually the result of direct impact to the anterior knee. This can occur when the knee strikes hard ground or some other hard sport surface. A football player with a poorly fit knee pad may be vulnerable if the player falls onto the knee. Another example is a tennis player who lands on the knee on concrete or asphalt.

Tests for knee injuries

Anterior Drawer Test
Posterior Drawer Test

Aply Compression test
Lachman's test