chapter 10: the knee
DESCRIPTION
Chapter 10: The Knee. The bones that comprise the knee joint: Tibia Fibula Femur Patella There are two joints in the knee: Tibiofemoral joint Patellafemoral joint. Anatomy. Anatomy. The medial and lateral meniscus rest between the femur and tibia. - PowerPoint PPT PresentationTRANSCRIPT
Chapter 10:The Knee
Anatomy
• The bones that comprise the knee joint:
• Tibia• Fibula• Femur• Patella
• There are two joints in the knee:
• Tibiofemoral joint• Patellafemoral joint
Anatomy
• The medial and lateral meniscus rest between the femur and tibia.
• They are responsible for shock absorption, improved bony correlation, joint lubrication, improved weight distribution, and decreased friction.
• The patella guides the quadriceps, decreases friction during movement, and protects the femoral condyles.
Anatomy of the Knee• Knee is a hinge joint• Articulation (point of
contact)– Consists of 3 bones
• Stabilized by– Four major ligaments– Cartilage– Strong musculature
• Knee is able to rotate
Cartilage• Ends of the tibia and femur
– Covered/cushioned by• Pieces of tough cartilage tissue• Called menisci
– Help to stabilize the knee joint– Without bones would rub & wear down quickly
• Top of tibia– Flat like a tabletop
• End of femur– Rounded (called condyles)– Without stabilization, femur would move a lot on the
tibia
Cartilage-Menisci• Lateral & Medial
– Thicker on sides– Thinner in the middle– Form a dish-shaped
hollow– Attached to the top of
the tibia– Provide a seat for the
femoral condyles to sit in
– Femur moves but will not roll off
Ligaments• 4 primary knee ligaments
– Medial collateral (MCL)• Helps provide stability to inside of
knee– Lateral collateral (LCL)
• Helps provide stability to outside of knee
– Anterior cruciate ligament (ACL)• Keeps tibia from moving forward on
the femur– Posterior cruciate ligament (PCL)
• Prevents tibia from moving backward on the femur
• ACL & PCL– pass through the middle of the knee
joint– Cross each other (i.e cruciate
means “cross-shaped”)
Ligaments of the Knee
• Anterior cruciate ligament (ACL)
• Posterior cruciate ligament (PCL)
• Medial collateral ligament (MCL)
• Lateral collateral ligament (LCL)
Anatomy• Muscles of the Knee
• Quadriceps muscles• Responsible for knee extension
• Hamstring muscles• Responsible for knee flexion
• Calf muscles• Assist in knee flexion
• Other muscles that act at the knee• Sartorius• Popliteus• Plantaris• Gracilis
Muscles of the Knee• Provide
– Movement– Stability
• Primary muscles spanning the knee– Quadriceps group (perform knee extension)
• Vastus medialis, vastus lateralis, vastus intermedius & rectus femoris
– Hamstring group (perform knee flexion)• Biceps femoris, semimembranosus & semitendinosus• Help prevent forward movement of the tibia on the
femur– By the location of their attachments
Primary Muscles Spanning the Knee
• Quadriceps group– Vastus medialis, vastus
lateralis, vastus intermedius & rectus femoris
– Perform knee extension
Primary Muscles Spanning the Knee
• Hamstring group– Biceps femoris,
semimembranosus & semitendinosus
– Perform knee flexion
– Help prevent forward movement of the tibia on the femur• By the location of
their attachments
Knee Alignment Concerns
• Genu valgum (knock-knees)• Genu varum (bow legs)• Genu recurvatum (hyperextension)• Q-angle
– Greater than 20 increases risk for injury• Leg length discrepancy
Preventing Knee Injuries• Ligament sprains
– Most common injuries seen at the knee– Muscles provide stability to the knee
• Help resist abnormal bony movement• Athletes should develop strength in the muscles
(quads, hams, gastrocnemius/calf, hip abductors & hip adductors)
– Gastrocnemius-heel raises
– Some trainers & athletes use preventative knee braces• Designed to protect medial collateral ligament
– Tearing can result from a blow to the lateral side
Treating Knee Injuries & Conditions
• Knee is exposed to many forces• Makes it vulnerable to injuries
– Especially the ligaments• Tendon & bone injuries also occur• Patella & menisci are subject to
unique types of athletics-related injuries
Ligament Injuries
• Ligament sprains of the knee– Can be
• Mild• Moderate• Severe
Injuries of the Knee
Patellar Fracture
• Signs & Symptoms:• Pain directly over bone • Slight to moderate swelling • Pain, especially in the first 30º of
movement• Treatment:
• Immobilize and refer to a physician for x-rays
• Requires lengthy immobilization during recovery
Patellar Dislocation • Signs & Symptoms:
• Moderate to extreme pain • Moderate swelling • Complete loss of ROM in knee • Obvious deformity laterally
• Treatment:• Refer to physician for reduction• RICE therapy• Progressive strengthening
program
Patella Dislocation• Patella forced to lateral
aspect of the knee• Often occurs when the knee
is bent and forced to twist inward
• Signs & symptoms– Obvious deformity– Athlete is often in distress
• EMS must be called– Unless team physician is
present• only a physician should
reduce a dislocated patella– Complications may result– Posterior aspect of patella
may be injured further
OUCH!!!!!!!!!
Patella-Femoral Stress Syndrome
• Signs & Symptoms: • Pain and tenderness in lateral aspect
of patella • Slight swelling • Crepitus or popping with extension
• Treatment:• RICE therapy• Closed kinetic chain exercises 0-40
Patellar Femoral Syndrome• Fancy name for a set of
symptoms that include pain/discomfort around patella
• Often caused by patellar tracking problems– Knee bends– Patella is grated across the
femur– Causing cartilage on back of
patella to soften or wear away
– Known as chondromalacia
Chondromalacia
• Signs & Symptoms:• Pain underneath the patella • Grinding or popping during motion • Slight chronic swelling
• Special Tests: Clarke’s Sign
• Treatment:• RICE Therapy• Quadriceps strengthening
Patellar Femoral SyndromeChondromalacia
• Characterized by achiness around the patella– Especially with prolonged
sitting in the same position
• Athlete reports a grinding sensation with flexion/extension– Grinding can be felt by
placing hand over knee
Patella Injuries (Chondromalacia)
Osgood-Schlatter’s Disease
• Signs & Symptoms:• Pain at insertion of patella tendon• Tenderness to palpation • Enlarged tibial tuberosity • Pain with jumping or running
• Treatment:• RICE therapy• Decrease activity or cross-train
Osgood-Schlatter Disorder• Irritation at the site of
the patellar tendon attachment– To front of the tibia
• Called tibial turberosity• Repeated stress
causes the patellar tendon to partially pull away from the bone– Called Osgood-
Schlatter’s disorder
Osgood-Schlatter Disorder• Signs & symptoms
– Discomfort of the knee• Swelling• Tenderness• Pain during activity• Possible bump below knee cap (bony growth at the top of the tibia)
– Can remain even after symptoms have disappeared• Care
– Restrict activity until resolved– Stationary bicycling– Use pain as a guide
• Modify activities based on pain level reported by athlete– Ice before & after activity– Special pad made to fit over front of tibia
• Often improves by age 16 or 17 (but known to last into early 20’s)
Patellar Tendinitis • Signs & Symptoms:
• Pain in patella tendon or at inferior pole of patella
• Pain increases with activity • Squeaking noise with motion• Slight swelling
• Treatment:• Modality treatment • Ice or ice massage• Ultrasound
Muscle & Tendon Injuries• Patellar tendinitis
– Overuse disorder• Characterized by quadriceps weakness• Tenderness over the patellar tendon• Minimal swelling
– Condition is also called jumper's knee• Athletes that do lots of jumping often get this condition
(basketball, volleyball)– Early stages
• Athlete typically has pain after activity– Treatment
• Trainer attempts to control inflammation– Apply ice– Modify athlete’s activity level
» Restricting running & jumping– Rehabilitation program
• Address any flexibility problems or weakness of the leg
Patella Tendon Rupture
• Signs & Symptoms: • Extreme pain with an immediate drop
in pain • Significant swelling • Window shade effect• Complete loss of knee extension • Previous history of chronic tendinitis
• Treatment:• Surgical repair is the only treatment
option• 6-8 months minimum recovery
Ruptured Patella Tendon
Knee Dislocation• Signs & Symptoms:
• Immediate pain that may decrease dramatically
• Obvious deformity (usually anteriorly)• Significant swelling• Decreased blood flow and neural
sensation • Treatment:
• Splinted and transported to hospital immediately
• Surgical intervention is often required for neurovascular and ligament repair
Knee Contusion
• Signs & Symptoms: • Pain at affected site • Moderate swelling and discoloration • Loss of ROM • Decreased weight bearing
• Treatment:• RICE therapy
Patella Injuries (Bursitis)
Prepatellar bursitis is the inflammation of a small sac of fluid located in front of the kneecap. This inflammation can cause many problems in the knee.
Causes Bursitis is the
inflammation of a bursa. The prepatellar bursa can become irritated and inflamed in a number of ways.A direct blow or a fall onto the knee can damage the bursa.
Meniscus Contusion
• Signs & Symptoms: • Pain, especially at full extension• Loss of ROM in extension • Slight swelling
• Treatment:• RICE therapy
Meniscus Tears
• Signs & Symptoms: • Pain, especially when moved similarly
to the mechanism of injury• Pain with full extension or flexion • Diffuse swelling in the joint (effusion) • Pain along the line of the joint • Sensation of locking or giving out • Clicking or popping sound with
movement
Meniscal InjuriesMeniscal injuries damage the cushioning tissue between the tibia and the femur, inside the knee joint, on both sides (medial and lateral) of the knee.
Causes They are highly
vulnerable to injury from abrupt rotations of the knee while it is bearing weight, for example, when you turn to hit a tennis ball, rotating your thigh (femur) while leaving your foot stationary.
Types of Meniscal Tears
MRI Torn Medial Meniscus
Arthroscopic Repair
Posterior horn tear with multiple flaps
Meniscus Tears
• Special Tests:• McMurray’s Test• Apley’s Compression Test • Bounce Home Test
• Treatment:• Referral to a physician • Surgery is often required for full
recovery.• RTP depends on surgical option
selected.
ACL Sprain
• Signs & Symptoms: • Pain in the joint • Athlete hears ‘pop’ at time of injury • Sense of looseness in joint, giving
away, or shifting• Swelling that increases rapidly post-
injury
Anterior Cruciate Ligament Injuries• Keeps tibia from moving
forward on the femur• If ligament is injured
– Athlete is often disabled– Complaining of the knee
“giving away”, collapsing & popping
• Most serious of all knee ligament injuries
• Most frequently surgically reconstructed
Anterior Cruciate Ligament Injuries• Often injured as the
athlete is attempting to change directions quickly– Twists the lower leg– May hear a popping
sound during the twisting• Also injured during
excessive hyperextension
Anterior Cruciate Ligament Injuries• Signs & symptoms
– Rapid swelling– Loss of knee function
• Immediate treatment– PRICE– Knee immobilizer– Crutches
• Follow up with an orthopedist is necessary
• Athlete rarely can continue a high level of function with a torn ACL
Anterior Cruciate Ligament Injuries
• Often needs to be surgically reconstructed– Determination that must be
made by the athlete, surgeon & athlete’s family
– Depends on the amount of instability that exists
– Level of function desired by the athlete
– Age of the athlete
Anterior Cruciate Ligament InjuriesKnee Arthroscopy
Anterior Cruciate Ligament InjuriesKnee Arthroscopy
ACL has poor healing potentialPCL has intermediate healing potentialMCL heals on its own
Bone Tendon Bone
Patella Tendon Graft
Anterior Cruciate Ligament InjuriesRehabilitation
• Focuses on strengthening the hamstrings– Helps stabilize the tibia– Helps regain full function– Even with aggressive ACL rehab
• May be six months before athlete can return to participation
ACL Sprain, cont.• Special Tests:
• Anterior Drawer Test• Lachman’s Test• Pivot Shift Test
• Treatment:• Grade 1 or 2 may be treated conservatively.• Grade 3 tear will require surgery.
PCL Sprain • Signs & Symptoms:
• Pain in posterior aspect of knee • Slight swelling • Joint laxity • Loose feeling with walking
• Special Tests:• Posterior Sag Test• Posterior Drawer Test
• Treatment:• Grade 1 or 2 may be treated
conservatively• Grade 3 tear will require surgery
Posterior Cruciate Ligament Injuries
• Prevents posterior tibial movement on the femur
• Frequently injured when– athlete falls and a bent
knee bears full weight– Knee is forcefully
hyperflexed– Blow delivered to the
front of the tibia
Posterior Cruciate Ligament Injuries• Assessment
– Trainer determines mechanism of injury– Athlete reports having heard a pop– Often little swelling with PCL injury
• Initial treatment– PRICE– Referral to a physician
Posterior Cruciate Ligament Injuries
• Physicians disagree about whether or not surgery should be performed on a severe PCL injury– Even complete PCL tears can be rehabilitated without
surgery• Rehabilitation programs for mild/moderate PCL
sprains– Focus on strengthening the quadriceps– Regaining full function
• Many athletes can become functional again– After initial pain & swelling are controlled– After knee is strengthened
MCL Sprain
• Signs & Symptoms: • Pain increasing with severity • Joint stiffness • Slight to moderate swelling • Decreased ROM • Joint laxity medially
Medial CollateralLigament Sprains
• Frequently injured when an athlete receives a blow to the outside of the knee– Causes knee to bend inward
(valgus stress)– Stresses the MCL
• Mild sprain– Medial joint line pain– Little if any swelling– No joint laxity when stressed
by trainer during assessment– Full knee flexion & extension
Medial Collateral Ligament Sprains• Moderate MCL sprain
– Mild swelling– Discomfort– Some joint laxity when
stressed by the trainer during assessment
• Severe MCL injury– Moderate or severe amount
of swelling– Loss of function– Great deal of joint laxity
when stressed by the trainer during assessment
Medial Collateral Ligament Sprains• Treated with PRICE• Mild injury
– Elastic wrap for compression/support
• Moderate/severe injury– Knee put in an immobilizer– Trainer should consider
possibility of damage to the menisci or an ACL injury
• Rehabilitation– Focuses on strengthening
the muscles that cross the medial aspect of the knee
MCL Sprain, Cont.
• Special Tests:• Valgus Stress Test• Apley’s Distraction Test
• Treatment:• RICE Therapy• Immobilization• Progressive strengthening program
LCL Sprain
• Signs & Symptoms:• Pain over lateral aspect of knee • Slight to moderate swelling • Joint laxity laterally • Joint stiffness • Decreased ROM
Lateral Collateral Ligament Injuries• Occur less frequently than MCL
injuries• Signs & symptoms are similar to MCL
– Except discomfort is at the lateral aspect of the knee
• Treatment– Same as MCL
• Rehabilitation (regaining joint stability)– Strengthening exercises focus on the
lateral thigh muscles & hamstrings
LCL Sprain, cont.
• Special Tests:• Varus Stress Test• Apley’s Distraction Test
• Treatment:• RICE Therapy• Immobilization• Progressive strengthening program
Discussion Questions
• What would be your response to an athlete who wants to play with an ACL tear?
• How would you react on the field if an athlete dislocated their knee?