Chapter 18 The Knee

Objectives Upon completion of this chapter, you should be able to: Describe the functions of the knee Describe the ligament structure of the knee Explain the function of the patellofemoral joint List and define various sports-related injuries of the knee

The Knee One of the most complex joints in the body Most movements and activities depend on it for support and mobility There is risk of overuse and traumatic injury in both contact and noncontact sports

The Knee (cont’d.) Two types of cartilage in the knee joint: Articular cartilage Menisci

The Knee (cont’d.) Ligaments Medial collateral ligament (MCL) Lateral collateral ligament (LCL) Anterior cruciate ligament (ACL) Posterior cruciate ligament (PCL)

The Knee (cont’d.) Patellofemoral joint Allows knee flexion and extension to occur with a lesser amount of quadriceps force

Knee Injuries Patellofemoral problems Articulation of the patella with the femur Symptoms: aching pain in the front or behind the knee, knee is giving way, crepitus, patellofemoral joint pain, and mild swelling Treatment: correct suspected causes, shoe inserts, taping and bracing, and stretching

Knee Injuries (cont’d.) Patellar tendonitis Inflammation of the patellar tendon Caused by high-force, repetitive strain Symptoms: anterior knee pain and local tenderness Treatment: activity modification, stretching, ice, bracing, and taping

Knee Injuries (cont’d.) Fat pad syndrome Infrapatellar fat pad is a region of fatty tissue that lies underneath the patellar tendon Symptoms: pain just below the patella, tenderness, and swelling Treatment: special strengthening exercises, taping, icing, and anti-inflammatory medications

Knee Injuries (cont’d.) Medial collateral ligament (MCL) sprain Caused by a blow to the outside of the knee or a high-energy twisting Symptoms: limited motion, swelling of the medial knee, tenderness, and pain Treatment: PRICE, protective wrap, a brace or crutches, rehabilitation

Knee Injuries (cont’d.) Torn anterior cruciate ligament Females are now more susceptible Can occur from contact or noncontact causes Symptoms: hearing a “pop” followed by effusion, knee buckling, nausea Treatment: splinting, icing, and compressive wrapping, crutches, reconstructive surgery, rehabilitation

Animation - ACL Click Here to Play ACL Animation

Knee Injuries (cont’d.) Posterior cruciate ligament tear Most occur during a fall on the flexed (bent) knee with the foot plantar flexed or hyperflexion (bending too far) of the knee Symptoms: positive “sag test” Treatment: PRICE, physical therapy and rehabilitation

Knee Injuries (cont’d.) Meniscus tears Occur when the knee is twisted suddenly and one or both menisci become trapped between the femur and tibia or ligaments in and around the knee are torn Symptoms: slow and mild knee swelling, pain, popping, locking, or giving way of the knee Treatment: compressive wrap, crutches, knee supports, activity modification, medications, and physical therapy

Knee Injuries (cont’d.) Epiphyseal (growth-plate) injuries Knee is subject to sports-induced trauma at the centers of bone growth in skeletally immature athletes May alter the length of the affected bone Serious injury for a growing athlete

Knee Injuries (cont’d.) Osgood-Schlatter condition Group of symptoms involving the tibial tubercle epiphysis Symptoms: pain, swelling, weakness, and a visible lump Treatment: preventing progression, protective gear, ice, improving flexibility, and stretching

Knee Injuries (cont’d.) Iliotibial band syndrome Occurs when there is inflammation of the iliotibial band Irritation usually occurs over the outside of the knee joint, at the lateral epicondyle Treatment: rule out mechanical problems or training errors, proper footwear, ice, and stretching

Knee Injuries (cont’d.) Fractures Result of high-energy trauma Vary in location and severity Patella fracture is usually the result of direct impact to the anterior knee Distal femoral and proximal tibial fractures may occur from violent twisting injuries

Conclusion The knee is the largest joint in the body, and one of the most prone to injury Made up of the femur, tibia, and patella Also contains large ligaments that help control motion These ligaments connect bones and brace the joint against abnormal types of motion Other parts of the knee, like cartilage, cushion the joint and help it absorb shock during motion