Knee Injuries Chapter 9

Anatomy The Knee is known as a HINGE joint. –It has also known to rotate. There are several structures that make up the knee: – 4 major ligaments –Cartilage –Strong muscles

Anatomy of the Knee

Medial Condyle Lateral Condyle Tibial Plateau

Bones The bones that make up the knee joint are the Femur (thigh), Tibia (shin) and the patella (knee cap). –Primary movement between the femur and the tibia. Forming the Tibiofemoral joint. –The patella glides up and down on the femur as the knee extends and flexes. Forming the patella femoral joint. The patella is a sesamoid bone (floating bone)

Cartilage The thick cushioning layer of tissue between the femur and the tibia is known as the Menisci (plural) or meniscus (singular). –They are two “C” shaped pieces of cartilage that are attached to the tibial plateau. –They are thicker on the outside of the disc and thinner on the inside of the disc. –They help to stabilize the knee joint and allow for fluent movement in the joint.

Menisci

Ligaments 4 major ligaments stabilize the knee. –MCL- medial collateral ligament –LCL- lateral collateral ligament –ACL- Anterior cruciate ligament –PCL-posterior cruciate ligament

Ligaments of the knee

Cruciate Ligaments

Primary Ligaments MCL- Medial Collateral Ligament –Provides stability to the Medial side of the knee LCL- Lateral Collateral Ligament –Lies underneath the IT Band (Illiotibial Band) –Provides stability to the Lateral side of the knee ACL- Anterior Cruciate Ligament –Attaches on the Anterior aspect of the tibial plateau –Is one of the most important stabilizers of the knee. PCL- Posterior Cruciate Ligament –Attaches on the Posterior aspect of the tibial plateau. –Is one of the other most important stabilizers of the knee.

Muscles of the Knee The Primary muscles that articulate on the knee span from the Quadriceps and the Hamstrings. The provide both movement and stability to the knee joint. Quadriceps are primarily used for Knee Extension – helps prevent the tibia from moving backward. Hamstrings are primarily used for Knee Flexion –helps prevent the tibia from moving forward.

Quadriceps There are 4 muscles that make up the Quadriceps: ( Attach from the ilium and the femur to the tibial tuberosity) –1. Rectus Femoris –2. Vastus Lateralis –4. Vastus Medialis –Vastus Intermedius

Hamstrings The hamstrings include 3 muscles: ( Attach from the posterior aspect of the lower pelvis to the posterior tibia) –1. Biceps Femoris (Long Head) –2. Biceps Femoris (Short Head ) –3. Semimembranosus –4. Semitendinosus

Pes Anserine Tendon

Other Structures Important to the Knee Bursaes: –Infrapatellar Bursae –Suprapatellar Bursae –Prepatellar Bursae

Other Structures Important to the Knee Iliotibial Band (IT band) Attaches on the Tensor Fascia Lata muscles and to the proximal tibia

Preventing Knee Injuries Ligament sprains are the most common injuries seen in the knee. The muscles are what help provide stability to this joint so strengthening of the quadriceps, hamstrings, calf, hip adductors and hip abductors. Some athletes and ATC’s use preventative knee braces that are designed to protect.

Ligament Injuries Just like in other joints of the body the ligaments in the knee can sustain injuries at a level of mild (1 st ), moderate (2 nd ) to severe (3 rd ). The Four Primary ligaments are those most commonly injured.

ACL ACL injuries are most often the most serious of all ligament injuries and the most frequent ligament reconstructed. The ACL prevents the Tibia from sliding forward on the femur. When this ligament is injured the athlete will often be disabled, hear a popping or may collapse on the floor and may complain of the leg just “giving way”.

Some Interesting Statistics According to 1998 injury statistics from the U.S. Consumer Product Safety Commission, more than 81,600 people injured their knee playing soccer, and 225,800 sustained injuries in basketball. Gymnastics, soccer and basketball are followed by field hockey, volleyball, lacrosse and softball as sports that cause ACL injury in females. (4) Studies show that women are 2 to 8 times as likely as men to have an ACL injury. (4) In 1995, an article was published in the American Journal of Sports Medicine that found that female basketball players in the NCAA tore their ACLs four times more often than male basketball players. In the same study, women who played NCAA soccer sustained ACL injuries twice as often as male soccer players. An estimated 200,000 ACL injuries occur annually in the United States. Approximately 60,000-75,000 ACL reconstructions are performed each year.(6)

Anatomical Differences with Gender

Mechanisms of Injury –Planting the foot and changing direction quickly allowing for the femur to twist and the tibia to stay still. -OR- –Excessive hyperextension

Mechanisms that cause ACL Tears

ACL Cont… A torn ACL will cause: –Usually a loud popping sound –Rapid swelling –Loss of knee function Treatment: –P.R.I.C.E –Immobilization –Crutches –Follow up with an Orthopedist.

ACL Cont… After sustaining an ACL injury it is difficult to continue with high level activity. –Running and cutting becomes difficult because the stability in the Knee is dramatically decreased without this ligament. –The deciding factors of whether or not to get the surgery are amount of instability, level of function desired by the athlete or age of the athlete. A reconstruction usually must be done in order for the athlete to fully recover from the injury. –After surgery rehabilitation usually lasts about 6-8 months. Rehabilitation of an ACL reconstruction includes strengthening of the hamstrings and ROM.

Patellar Tendon Graft

Harvesting the Graft

Infrapatellar Tendon Graft

Drilling

Hamstring Tendon Graft Harvest

Preparing the Graft

PCL Prevents posterior movement of the tibia on the femur. Mechanism of Injury: –When an athlete falls and a bent knee bears his full weight. -or- –When the knee is forcefully hyperflexed. -or- –A blow is delivered to the front of the tibia. ( This usually occurs when a person is involved in a car accident and the dash board is pushed into their legs.)

PCL Cont… With a PCL injury they may hear a loud popping sound like with the ACL There is usually very little swelling Usually after hearing the mechanism of injury is what clues the ATC into thinking it may be a PCL injury.

PCL Cont… Treatment: –P.R.I.C.E It is still debated whether or not an athlete needs to undergo a reconstruction of the PCL Strengthening of the quadriceps is a major part of rehabilitation. Many athletes can become functional again after the initial pain and swelling are controlled.

MCL Usually injured when a valgus stress is placed on the knee. –1 st degree (mild)- medial joint pain, little if any swelling, not laxity, full knee ext. and flex. –2 nd degree (moderate)- mild swelling, discomfort, and some laxity. –3 rd degree ( severe)- moderate or severe swelling, significant laxity, and loss of function.

MCL cont… Treatment- –P.R.I.C.E –Mild- ace wrap for support –Moderate to severe – knee immobilizer –Strengthen muscles that cross the joint ( with significant damage to the MCL one must consider possible ACL and/or Meniscus)

LCL Very infrequently injured. Signs and Symptoms are the same as the MCL. Strengthening should include lateral leg muscles as well as the hamstrings.

Patellar Tendonitis “Jumpers Knee” Overuse disorder characterized by quadriceps weakness and tenderness over the patellar tendon, with minimal swelling.

Treatment Treat for inflammation –Ice –Anti-inflammatories –Knee straps –Modify activity( restricting jumping and running) Work on flexibility and/or weakness of the leg.

Bone Injuries The patella is not immune to fractures but more likely chondromalacia will occur or a patellar dislocation.

Patellar Femoral Syndrome Generic for pain and discomfort around the patella. –Pain is usually caused by a tracking problem of the patella. –When the knee is bend and it grades across the femur tearing away at the cartilage it is known as Chondromalacia. Sitting for long periods of time will aggravate it, and will c/o grinding with flexion and extension of the knee Treatment- –Fixing the tracking problem- taping, strengthening VMO, avoid bent knee activity and increase flexibility of Quads and hamstrings.

Patella dislocation The Patella can be forced to the lateral side of the knee. Mechanism of injury- –While knee is bent and is forced into a twisting movement inward. Signs and symptoms- –Very hard to overlook and usually the athlete is in distress Treatment- –Only a physician should relocate a dislocated patella b/c problems could occur posterior to the patella. –Immobilization initially –Strengthening –Bracing

Meniscal Injuries The most common injury to the meniscus is a tear. ( Can occur to the outer edge, middle, or inside edge.) Mechanism of Injury- –Usually occur because of a twisting motion, hyperflexion or hyperextension injuries. Signs and Symptoms- –Pain in the joint line, problems weight bearing, c/o clicking, catching or locking; walk with limp, unable to fully extend or flex without pain Treatment- –Used to be treated by removing the entire meniscus –Now, arthroscopic surgery, involving removing only the pieces that are torn. –Depending on where the tear is will depend on whether they can repair the tear by sewing. –Rehabilitation should include non weight bearing activity (aquatic therapy)

Different types of Meniscal Tears

Osgood-Schlatter Disorder Younger athletes who perform a lot of running and jumping will have irritation where the insertion of the patella tendon on the tibia. (Gerdy’s Tubercle) Their bones are still soft and immature which sometimes will cause the tendon to partially pull away from the bone. (Osgood- schlatters) Signs and Symptoms- –Discomfort, swelling, tenderness, and pain during activity. Treatment- –Restrict activity until resolved –Knee strap –Ice –Anti-inflammatories –Continue with Cardio (Stationary bike) –Modify activity in regards to pain.

Iliotibial Band Friction Syndrome Acute inflammatory condition- –Friction that occurs when the IT-band rubs over the lateral femoral epicondyle. –Usually a overuse injury by repetitive running or flexion and extention. Signs and Symptoms- –Worse climbing hills or stairs –Gait may change trying to keep the knee in full extension Treatment- –Rest + decrease activity –Ice –Anit-inflammatories –Stretching –Sometimes Corticosteroid injections.