it concentrates mainly on the movements of the knee joint and locking and unlocking of knee joint. it is more easy and simple and complete

2. MOVEMENTS
LOCKING AND UNLOCKING OF THE
KNEE JOINT
By M.Aravind
MBBS Ist year
DSMCH
Perambalur
MOVEMENTS
LOCKING AND UNLOCKING OF THE KNEE
JOINT

3. KNEE JOINT
 It is the largest joint of
the body
 It is formed between
lower end of femur,
upper end of tibia and
patella
 The condyles of femur
 The patella
 The condyles of tibia
ARTICULARSURFACES

4. Type
 A modified hinge type of synovial joint (as
some degree of rotation takes place during
locking and unlocking of the joint.
Weak joint
 Articular surfaces are not congruent
 Tibial condyles are shallow
 Femoropatellar articular surfaces are shallow
 Outward angulation between the long axis of
leg and knee

5. Strength of the
knee joint
 Cruciate ligaments maintain
anteroposterior stability
 Collateral ligaments maintain
side to side stability
 Capsule is strengthened by
 Anterior- medial and lateral
patellar retinacula
 Posterior- oblique popliteal ligament
 Medial- expansions from tendons
of sartorius and semitendinosus
 Lateral- illiotibial tract

6. Complexity of the joint
 The joint consists of two
parts
 Condylar synovial joint-
between two femoral
condyles and tibial
condyles
 Saddle joint- between the
lower end of femur and
patella

7. Movements at the knee joint
Flexion and extension Medial and lateral rotation
 Chief movements
 Takes place in upper
compartment of the joint,
above the menisci
 Takes place around
transverse axis
 Small range of movements
 Takes place in the lower
compartment of the joint,
below the menisci
 Takes place around vertical
axis

9.  During different phases of movements of
knee different portions of patella articulate
with the femur.
 Extension- lower pair of articular facets
 Beginning of flexion- middle pair
 Midflexion-upper pair
 Full flexion-
medial strip

10. Muscles producing movements at
the knee joint
 EXTENSION- Quadriceps femoris
 FLEXION- Biceps femoris, semimembranosus,
semitendinosus
 MEDIAL ROTATIONOF FLEXED LEG-
Popliteus, semimembranosus, semitendinosus
 LATERAL ROTATIONOF FLEXED LEG- Biceps
femoris
 LOCKING- Vastus medialis
 UNLOCKING- Popliteus

12.  Have you ever noticed thatYou stand for a
long time without much muscular effect. How
is it possible?
 It is due to locking mechanism of knee joint

13. LOCKING OF KNEE JOINT
 The anteroposterior diameter of the lateral
femoral condyle is less than that of the
medial condyle.
 Therefore the lateral condylar surface is fully
used up
 It serves as the axis around which the medial
condyle rotates medially so that the
remaining part is used up.
 All the ligaments of the knee joint are taut.

14. Locking Unlocking
 During last 30 degrees of
extension
 Medial rotation of femur
 Helped by quadriceps femoris
(mainly vastus medialis)
 As standing at attention
 The ligaments are taut
 During initial stages of flexion
 Lateral rotation of femur
 Helped by popliteus
 As standing at ease
 The ligaments are relaxed

15. Accessory or passive movements
performed in a partially flexed
knee
 A wider range of rotation
 Anteroposterior gliding of the tibia on the
femur
 Some adduction and abduction
 Some seperation of the tibia from the femur

16. CLINICAL ANATOMY
 OSTEOARTHIRITIS
 CONDITION-Degeneration
of the articular surfaces
 CAUSES- Ageing,congenital deformity, fracture
around the knee joint
 DEFORMITY- Limited movements, pain
 BAKER’S CYST- Synovial membrane protrudes
through a hole in the posterior surface of the
knee joint, central swelling
 SYMPTOMS: Knee pain, stiffness, swelling

17. KNEE REPLACEMENT
TREATMENT
 In the past such
patients had to depend
on heavy doses of
analgesics to relieve
pain
 Now the entire joint
can be replaced using
artificial materials
giving long lasting
relief to many

19. DEFORMITIES OF THE KNEE
GENUMVALGUM OR KNOCK
KNEE
GENUMVARUM OR BOW
KNEE
 LEG MAY BE
ABNORMALLY
ABDUCTED
 LEG MAY BE
ABNORMALLY
ADDUCTED
CAUSES
 RICKETS
 POSTURE
 CONGENITAL ABNORMALITY

21. DISLOCATION OF THE KNEE
JOINT
 Rare
Results in damage to
 Poplital artery
 Tibial nerve or
 Common peroneal nerve

22. INJURIES IN THE REGION OF
KNEE JOINT
 TRAUMATIC SYNOVITIS- joint cavity filled
with serous fluid
 HAEMARTHROSIS- joint filled with blood
 RHEUMATOIDARTHIRITIS- autoimmune
condition
 GOUT- deposition of sodium urate crystals
 PSEUDOGOUT- deposition of calcium
phosphate crystals
 SEPTIC ARTHIRITIS- bacterial infection

23. KNEE TESTS
 ARTHROSCOPY
 Arthroscopy involves the introduction of a
lighted instrument into the synovial cavityof
the knee joint through a small incision.The
technique permits the direct visualization of
structures such as the cruciate ligaments and
the menisci for diagnostic purposes.
 Parts of torn menisci (ligaments) and other
parts of loose tissue can be removed
 KNEE X-RAY
 MAGNETIC RESONANCE IMAGING-
ligamental and meniscal injury

24. PNEUMOARTHROGRAPHY
 Air can be injected into the synovial cavity of
the knee joint so that the soft tissues can be
studied.This technique is based on the fact
that air is less radiopaque than structures the
medial and lateral menisci, so their outline
can be visualized on a radiograph

25. CONDYLES OFTIBIA
FIBULA
PATELLA
CONDYLES OF FEMUR
ARTICULATING
SURFACES
EXT
LR
FLE
MR
LOCKINGAND UNLOCKING
OSTEOARTHIRITIS
GENUSVARUM
ANDVALGUM

26. THANK YOU