1. Chapter 10: The Knee

2. Anatomy The bones that comprise the knee joint: Tibia Fibula Femur
Patella
There are two joints in the knee:
Tibiofemoral joint
Patellafemoral joint

3. 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.

4. 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

5. Cartilage Ends of the tibia and femur Top of tibia End of 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

6. 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

7. Ligaments 4 primary knee ligaments ACL & PCL 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”)

8. Ligaments of the Knee Anterior cruciate ligament (ACL)
Posterior cruciate ligament (PCL)
Medial collateral ligament (MCL)
Lateral collateral ligament (LCL)

9. 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

10. Muscles of the Knee Provide Primary muscles spanning the knee 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

11. Primary Muscles Spanning the Knee
Quadriceps group
Vastus medialis, vastus lateralis, vastus intermedius & rectus femoris
Perform knee extension

12. 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

13. 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

14. 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

15. 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

16. Ligament Injuries Ligament sprains of the knee Can be Mild Moderate
Severe

18. Injuries of the Knee

19. 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

20. 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

21. 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

22. OUCH!!!!!!!!!

23. 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

24. 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

25. 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

26. Patellar Femoral Syndrome Chondromalacia
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

27. Patella Injuries (Chondromalacia)

28. 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

29. 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

30. 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)

31. 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

32. 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

33. 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

34. Ruptured Patella Tendon

35. 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

36. Knee Contusion Signs & Symptoms: Pain at affected site
Moderate swelling and discoloration
Loss of ROM
Decreased weight bearing
Treatment:
RICE therapy

37. 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.

38. 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.

39. Meniscus Contusion Signs & Symptoms:
Pain, especially at full extension
Loss of ROM in extension
Slight swelling
Treatment:
RICE therapy

40. 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

41. Meniscal Injuries
Meniscal injuries damage the cushioning tissue between the tibia and the femur, inside the knee joint, on both sides (medial and lateral) of the knee.

42. 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.

43. Types of Meniscal Tears

44. MRI Torn Medial Meniscus

46. Arthroscopic Repair

47. Posterior horn tear with multiple flaps

48. 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.

49. 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

50. 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

51. 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

52. 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

53. 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

54. Anterior Cruciate Ligament Injuries Knee Arthroscopy

55. Anterior Cruciate Ligament Injuries Knee Arthroscopy

56. ACL has poor healing potential
PCL has intermediate healing potential
MCL heals on its own

61. Allograft
Bone
Tendon
Bone

63. Patella Tendon Graft

64. Anterior Cruciate Ligament Injuries Rehabilitation
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

65. 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.

66. 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

67. 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

70. 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

71. 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

72. MCL Sprain Signs & Symptoms: Pain increasing with severity
Joint stiffness
Slight to moderate swelling
Decreased ROM
Joint laxity medially

73. Medial Collateral Ligament 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

74. 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

75. 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

76. MCL Sprain, Cont. Special Tests: Valgus Stress Test
Apley’s Distraction Test
Treatment:
RICE Therapy
Immobilization
Progressive strengthening program

77. LCL Sprain Signs & Symptoms: Pain over lateral aspect of knee
Slight to moderate swelling
Joint laxity laterally
Joint stiffness
Decreased ROM

78. 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

79. LCL Sprain, cont. Special Tests: Varus Stress Test
Apley’s Distraction Test
Treatment:
RICE Therapy
Immobilization
Progressive strengthening program

80. 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?