This document discusses various ligaments in the knee including the collateral ligaments, anterior cruciate ligament (ACL), and posterior cruciate ligament (PCL). It describes the anatomy and function of each ligament, common mechanisms of injury, clinical signs used to diagnose injuries, investigations like MRI, and treatment approaches including conservative rehabilitation or surgical repair/reconstruction.

1. Collateral & Cruciate ligament
injuries - Knee

2. Knee
Related anatomy
Superficial, Uni-axial, load bearing joint
Structures stabilizing the knee
 Bone
 Soft tissue
 Synovium & capsule
 Ligaments: Collateral,
ACL and PCL
 Menisci : Medial & Lateral
 Muscles and tendons

3. Knee
Related anatomy
Structures stabilizing knee
Muscles and tendons
 Quadriceps
 Gastronemius
 Hamstrings
 Popliteus
 Iliotibial band
 Pes anserinus :
 Sartorius, Gracilis & Semitendinoses

4. Collateral ligaments
Related Anatomy
 Located at the inner and outer side of knee
 Connects femur to tibia (MCL) & fibula (LCL)
 Injuries by varus /valgus forces on knee
 The LCL is rarely injured

5. Collateral ligaments
Mechanism of injury
Varus / valgus force to knee: sports related
Partial & complete tears

6. Collateral ligaments
Clinical features
 Pain, swelling over medial / lateral aspect
 Inability to walk due to pain : instability: 0
tear
 Instability : giving way of the joint
 Depending on degree of tear (0 tear):
 Effusion : first degree tear
 Haemarthrosis : 2nd and 3rd degree tears
 Patella tap positive
 Varus / valgus stress test positive
 Apley’s distraction test

7. Apley’s distraction
test

8. Varus stress test
Valgus stress test

9. Management
Investigations
• Ligament injuries are not visualised on X-rays
• Often associated with Meniscal and ACL tears
• MRI useful to confirm diagnosis
Collateral ligaments
Grade 1 Grade 2 Grade 3

10. Management : Investigations
• Ligament injuries are not visualised on X-rays
• MRI useful to confirm diagnosis
Partial tear
Conservative treatment suffice
RICE : Rest, Ice, Compression, Elevation
 Rest the knee to give the ligament time to heal
 Ice : 2-3 / days :15 to 20 minutes each
 Compress the site to limit swelling
 bandage or brace for a while
 Elevate the knee whenever possible
Rehabilitation exercises for good healing
Collateral ligaments

11. Management
Complete tear
 May need surgery : repair returns stability
 Rehabilitation plan necessary
 After satisfactory rehabilitation, previous levels
of activity usually regained
Rehabilitation
 Passive ROM exercises to restore flexibility
 Braces to control joint movement
 Exercises : strengthen quadriceps
Collateral ligaments

12. Cruciate ligaments
 Derived from “crux”: meaning cross / “crucial”
 Criss-cross each other to form an “X"
 Intra-articular & connects femur to tibia
 Made of many strands & functions like short
ropes holding the knee joint tightly in place
when the leg is bent or straightened
 2 cruciates
 anterior cruciate ligament (ACL)
 posterior cruciate ligament (PCL)

15. ACL function
 Prevents tibia from
sliding forwards
beneath the femur
ACL injuries
Injured in several ways :
 Changing direction rapidly
 Landing: following a jump
(skiing, gymnastics)
 Direct contact: football tackle
Anterior cruciate ligaments

16.  May be isolated injury-usually combines with
mesiscus & collateral tears
 No pain immediately
 Knee gives way during
fall - popping sensation
- feel of structure tear
within knee-numbness
 Haemarthosis - pain
Anterior cruciate ligaments
Walking or running on an injured ACL, can further
damage the articular cartilage in the knee

17. Haemarthrosis and Effusion
Haemarthrosis Effusion
Swelling seen
immediately after the
injury : 15-20 minutes or
sooner
Swelling comes after >6-
12 hours of injury
Indicates cruciate or
peripheral meniscal lesion
in the absence of a
fracture
Indicates a tear of the
meniscal body or synovial
injury / irritation
Patella tap positive Patella tap positive

18. Diagnosis : Based on
Thorough physical examination of knee
 Anterior drawer test
 Lachman test
 Pivot shift test
Anterior cruciate ligaments
O’Donoghue’s
“unhappy” /
“terrible” triad

19. Anterior drawer test
Pivot-shift test
Sag
Sign

20. Lachman Test
Pivot-shift test

21. Pivot shift test
Pivot-shift test
 Knee held in extension
 Leg internally rotated
 Valgus force at knee
 Knee slowly flexed
Anteriorly subluxated tibia reduces on flexion

22. ACL
 X-ray : associated fractures
 MRI
 Arthroscopy: Diagnostic
Therapeutic
ACL Stump

23. ACL - arthroscopic view
Normal ACL
Torn ACL
Repaired ACL

24. Management
 Partial tear may or may not require surgery
 Complete tears, especially in younger
athletes - may require reconstruction
Conservative
 Used in overall low activity level patients
 If the overall stability of the knee is good
 Involves treatment program
 muscle strengthening
 use of a brace to provide stability
Anterior cruciate ligaments

25. Management
Operative treatment
 Arthroscopic
 Open surgery
 Combination
Procedure
Strip of tendon, taken from the patient’s knee
 patellar tendon
 hamstring tendon (semitendinosus)
passed through joint and secured to femur & tibia
Anterior cruciate ligaments

26. Operative : ACL
Patellar tendon graft

27. CPM machine
Rehabilitation : ACL

28.  Strong ligament
 Not frequent as ACL tear
Mechanism of injury
 A blow to front of knee
 Fall on a bent knee
 Dashboard injury
 Hyperextension : dislocated knee
 PCL injuries disrupt knee joint stability
because the tibia can sag backwards
 PCL injuries may be isolated or combined
Posterior cruciate ligament

29. Symptoms
 Immediate swelling - haemarthrosis, pain +
 Inability to walk : pain, instability
 Instability : knee “giving way”
Posterior cruciate ligament
Mechanism of injury : PCL

30. Clinical
 Sag test
 Posterior drawer test
 Quadriceps active test
 Reverse pivot shift test
PCL injuries
Sag Sign

31. Posterior drawer test : PCL Quadriceps active test

32. Posterior cruciate injuries
Investigations
 X-rays
 MRI
 Arthroscopy
PCL avulsion injury
Double PCL sign-
associated
bucket handle
tear of Med Mns
Normal PCL

33. Management
Isolated PCL injuries
 May be either partial or complete tears
 Can usually be treated conservatively
Combined PCL injuries
 Injury to ligaments, bone, nerves/blood vessels
 Usually require surgical repair
Posterior cruciate ligament

34. Structure Physical Test
ACL Anterior drawer, Lachman, Pivot-shift
PCL Posterior drawer, Posterior sag sign,
Quadriceps active test, Reverse pivot
shift test
Fib.col.lig Varus stress
Tib.col.lig Valgus stress
Patella Patellar apprehension for instability
Tests in the diagnosis injuries of ligaments