Chapter 7 Knee and Thigh

9/2/2015copyright Knee Anatomy Largest Joint of the body Structurally weak –Weakness due to unstable boney structure.

9/2/2015copyright Knee Anatomy Consider the femur the longest & strongest bone of the body. Sits on the much smaller tibia; which is the main weight bearing bone!

9/2/2015copyright Knee Femur / Tibia Condyles – 2 slightly convex surfaces on the distal end of the femur Condyles articulate with the slightly concave surfaces of the tibia –This is stable –However once the knee bends (like in walking & running) stability of these surfaces decrease.

9/2/2015copyright Knee Femur / Tibia

9/2/2015copyright Knee Femur / Tibia These two bones slide back & forth on each other. Even in non-athletic activities Add to the issue the lack of rotation of the joint

9/2/2015copyright Knee Fibula Non-Weight bearing bone Serves as the attachment for the Lateral collateral ligament (LCL) & the Bicep Femoris Muscle

9/2/2015copyright Knee Patella “knee cap” Incased in the powerful patellar tendon Moves up & down in front of the knee in the space between the 2 condyles of the femur

9/2/2015copyright Ligaments & Muscles Instability of boney structures is compensated by strong ligaments and even stronger muscles

9/2/2015copyright Ligaments & Muscles 4 Ligaments that stabilize the knee. 1.Medial Collateral Ligament 2.Lateral Collateral Ligament 3.Anterior Cruciate Ligament 4.Posterior Cruciate Ligament

9/2/2015copyright Ligaments & Muscles MCL Remember ligaments hold bones to bones. MCL – Helps secure the femur to the tibia Also connects to medial meniscus –Creates issue with evaluation –Not as strong as the MCL

9/2/2015copyright Ligaments & Muscles LCL Cordlike and does not attach to the meniscus Assists in valgus / varus movement of the knee.

9/2/2015copyright Ligaments & Muscles ACL / PCL Form an X in the middle of the knee Controls movement Posterior & Anterior movement of femur on the tibia.

9/2/2015copyright Ligaments & Muscles More than any other joint, the depends on good muscle support. There are 12 muscles that support the anatomical structures of the knee –Most of this support comes from the large muscles of the quad and lower leg.

9/2/2015copyright Ligaments & Muscles Quadriceps: Anterior –Rectus Femoris –Vastis medialialis –Vastus intermedialis Quads extends when straightened Hamstrings Posterior –Semitendinosis –Semimembranosus –Biceps femoris Controls rotary movements and flexes the knee.

9/2/2015copyright Ligaments & Muscles Other “less” popular muscles: Sartorius Gracilis Popliteus Gastronemius Plantaris Tensor Fascia Latae / Iliotibial Band (IT Band)

9/2/2015copyright Menisci Medial & Lateral Meniscus: 2 Tough, fibrous cartilages Rest on top of the Tibia

9/2/2015copyright Menisci Function: Form a cushion for Femoral Condyles Shock absorption Adds to Joint Stability Helps to smooth the gliding & rotating movements of femur and tibia

9/2/2015copyright Other Structures Bursae – closed, fluid filled sacs that serve as cushions against friction over a prominent bone, or whatever moves over a bone. Synovial Membrane – a large closed sac that lines the inside of the knee joint, helping to lubricate the tendons, ligaments, and bones. Fat Pads – specialized soft tissue structure for weight bearing and absorbing impact

9/2/2015copyright Nerves Dermatome – the sensory distribution of a nerve root; produces feeling in a certain anatomical area. Myotome – the motor distribution of a group of muscles innervated by a single nerve root; it produces movement of the anatomical structures.

Range Of Motion Flexion – Decreasing angle between the Femur and the Tibia Extension – Increasing the angle between the Femur and the Tibia Tibial Internal Rotation – Rotation of the Tibia toward the midline of the body Tibial External Rotation - Rotation of the Tibia away from the midline of the body

Range Of Motion Anterior / Posterior Translation – movement of the femur on the Tibia in a forward or backward movement pattern 22

Evaluation Proper evaluation is used to determine seriousness of the injury History Mechanism of injury, location of pain, sensations experienced, and previous history This will guide you through the rest of the evaluation Observation Compare the uninjured to the injured, look for: deformation, swelling, discoloration, scars, other signs of trauma or abnormality. 23

Evaluation Palpation Again; compare right to left Check for: Neurological Trauma Circulation (nail bed return / pulse) Anatomical structures Potential Fractures 24

Evaluation Special Test Start with strength evaluation Valgus / Varus Test – used to evaluate medial and lateral ligament stability Anterior / Posterior Drawer – Assesses stability of the ACL & PCL Lachman – Used to evaluate ACL Apley’s Compression – Evaluates the integrity of the menisci 25

Refer When…. Gross deformity Significant Pain Increase Swelling Circulation or neurological impairment Joint instability Suspect a fx or dislocation Dislocated patella Abnormal sensations such as clicking, popping, grating, or weakness Locked knee or excessive / limited motion Any doubt 26

Common Injuries Due to the complexity of the knee it is frequently injured It is possible to severely injure the knee & not get a lot of swelling. And get very little pain Ligament Sprains: can be cased by multidirectional forces and are compounded when the athlete's foot is stationary (planted) Most common is a direct blow to the lateral aspect of the knee injuring medial structures 27

Common Injuries Knee Ligaments are usually injured by one of the following methods: 1.Compression (Direct Blow) 2.Torsion (Fixed foot, twist body part or body) 3.Shearing (Forced applied to the opposite side of the joint) Sports that use cleats have an increase chance of injury. 28

Common Injuries All Ligamentous Sprains are classified the same. 1 st Degree Sprain – one or more supporting ligaments & surrounding tissue stretched. 2 nd Degree Sprain – A portion of 1 or more ligaments is torn. 3 rd Degree Sprain – 1 or more ligaments is torn. 29

Common Injuries Patellar Tendinitis Excessive stress placed on the patellar tendon cause inflammation above or below the patella Athlete complains of pain “when they first get up” and/or after activity. May have swelling. –Treat with Cold/Heat/Ultrasound/Rest –Rehab Strengthen Quads / Hamstrings 30

Common Injuries Chondromalacia Patellae A degenerative condition that results in the irritation and softening of the cartilage on the posterior aspect of the patella. –Running, jumping, kneeling, and climbing stairs will elicit pain –Causes muscle weakness or imbalance, body structure Treatment: Ice before & after activity –Surgery? Rehab: Again work on Strengthening 31

Common Injuries Female Athletes Knee (Anterior Superior Iliac Spine – ASIS) Patellar problem may be more prevalent in female athletes b/c of structural differences in the pelvic girdle. Wider pelvis creates a sharper angle where the femur attaches to the pelvis. 32

Common Injuries Female: Q Angle – an imaginary line from the ASIS to the medial edge of patella. copyright

Common Injuries A sharper Q Angle changes the line of pull of the quads and may cause the patella to be pulled laterally, with muscle contraction. Changes in mechanics can increase conditions like: –Chondromalacia –Patellar dislocation/subluxation –ACL? Key to treatment is pevention! –Strengthen medial aspects of quads (VMO) 34

Common Injuries Osgood-Slatters Common to adolescents due to rapid growth during “growth spurts” Characterized by swelling & point tenderness below 1 or both knees. –Can be caused by partial separation of the patellar tendon from tibial tubercle –Inflammation of the tibial tubercle 35

Common Injuries Whatever the cause it is aggravated by activity, relieved by rest In cases of long duration the front of the knee appears enlarged and a bony prominence can be felt. Although the condition is usually disappears after adolescence the boney prominence remains. 36

Common Injuries Other Musculoskeletal Disorders / Conditions Muscle strains Bursitis Dislocation (knee, patella) Iliotibial Band Friction Syndrome Meniscal Tear Myositis Ossificans Osteochondritis Dissecans (OCD) Popliteal Cyst 37