Download Biomechanics of the Hip, knee, and ankle

Biomechanics of the
Hip, knee, and ankle
James Bicos, MD
Performance Orthopedics
Director of Research, Performance Orthopedics
Assistant Professor, Oakland University William
Beaumont School of Medicine
William Beaumont Sports Medicine
Team Physician Oakland University
Disclosures
• Consultant for Biomet, Inc.
• Consultant for Bellevue
Pharmacy
• Royalties from Innomed, Inc.
Who is this guy?
• James Bicos, MD
• Sports Medicine Orthopedic
Surgeon
• Board Certified
• Specialize in:
• Shoulders
• Knees
• Cartilage Disorders
Who is this guy?
• Undergraduate:
• Northwestern University
• Residency:
• Rush Presbyterian
• Fellowship:
• UConn
Who is this guy?
• Team Orthopedic Physician
United States Gymnastics
Team
Hip Biomechanics
Hip Biomechanics
• The hip joint, or
coxofemoral joint, is the
articulation of the
acetabulum of the pelvis and
the head of the femur.
• The hip is a diarthrodial
ball-and-socket joint
• Three degrees of freedom:
• Flexion/extension
• Abduction/adduction
• Medial/lateral rotation
Hip Biomechanics
• The hip joint, or
coxofemoral joint, is the
articulation of the
acetabulum of the pelvis and
the head of the femur.
• The hip is a diarthrodial
ball-and-socket joint
• Three degrees of freedom:
• Flexion/extension
• Abduction/adduction
• Medial/lateral rotation
Hip Biomechanics
• The hip joint, or
coxofemoral joint, is the
articulation of the
acetabulum of the pelvis and
the head of the femur.
• The hip is a diarthrodial
ball-and-socket joint
• Three degrees of freedom:
• Flexion/extension
• Abduction/adduction
• Medial/lateral rotation
Hip Biomechanics
• Although we examine hip
joint structure and function
as if the joint were designed
to move the foot through
space in an open chain, hip
joint structure is more
influenced by the demands
placed on the joint when the
limb is bearing weight.
Structure of Hip
Joint and surfaces
• Acetabulum = cuplike
concave socket of the hip
• Located at the lateral part of
the pelvic bone
• Pelvic bone = made from 3
bones
• Ilium
• Ischium
• Pubis
Structure of Hip
Joint and surfaces
• Acetabulum = cuplike
concave socket of the hip
• Located at the lateral part of
the pelvic bone
• Pelvic bone = made from 3
bones
• Ilium
• Ischium
• Pubis
Structure of Hip
Joint and surfaces
• Pelvic bones fuse or ossify
between 20 – 25 years of age
• Especially in younger
athletes, the separate
segments of the pelvis can
be seen.
Structure of Hip
Joint and surfaces
• Acetabulum appears to be a
hemisphere but only the
upper margin is truly
circular
• The part of the acetabulum
that has cartilage is called
the lunate surface and is
horseshoe shaped
Structure of Hip
Joint and surfaces
• Acetabulum is deepened by
a cartilage structure called
the Labrum
• It surrounds the periphery of
the acetabulum
• It increases the concavity of
the acetabulum – makes it
more round
• It makes a seal (like a
gasket) that we think helps
preserve the cartilage with
lubrication
• Not a weight bearing
structure – does contain
nerve endings so probably
helps with proprioception
The proximal femur
• Other side of the hip joint
• Femoral head
• Round cartilage structure
• Slightly larger than a
hemisphere
• Curvature of the femoral
head is smaller in women
than in men
• Fovea – a roughened area on
femoral head, not covered
with cartilage, has
ligamentum teres
The proximal femur
• Femoral head attached to
femoral neck
• Femoral neck attached to
femoral shaft by greater
trochanter and lesser
trochanter
• The femoral neck places the
head at an angle in relation
to the shaft and allows for
the hip motion
The proximal femur
• There are two important
angles made between the
femoral head and shaft
•
•
Angle of Inclination
• About 126 deg
• Too much inclination is
called Coxa Valga
• Too little inclination is
called Coxa Vara
Angle of Torsion or Femoral
Anteversion
• When angled to the front –
called Anteversion
• When angled to the back –
called Retroversion
The proximal femur
• There are two important
angles made between the
femoral head and shaft
•
•
Angle of Inclination
• About 126 deg
• Too much inclination is
called Coxa Valga
• Too little inclination is
called Coxa Vara
Angle of Torsion or Femoral
Anteversion
• When angled to the front –
called Anteversion
• When angled to the back –
called Retroversion
Hip joint capsule and
ligaments
• Substantial contributor to
joint stability
• Dense fibrous structure with
3 – 4 thickened regions that
constitute the capsular
ligaments
• Attached proximally by
acetabulum
• Attached distally by femoral
neck
• The trochanters are outside
of the capsule
Hip Blood Supply
Common hip
disorders
Trochanteric Bursitis
Hip Flexor Tendonitis
Snapping Hip Syndrome
SCFE
Stress Fractures
Labral Tears
Trochanteric
bursitis
• Bursa between greater
trochanter of femur and
iliotibial band
• Caused by trauma, hip
surgery, repetitive
movement, spontaneous,
tight ITB
• Female:Male = 4:1
• Point tenderness over
greater trochanter
• Pain with rising from sitting
position, and lying on hip
Trochanteric
bursitis
• Treatment
• Physical therapy
• Ultrasound
• Graston soft tissue
• Stretching
• Injection
• Surgery as last resort
Hip flexor
tendonitis
• Also called Iliopsoas
tendonitis
• From repetitive flexor
contraction movements
• Anterior hip pain with
lifting leg, often times from
explosive maneuver
Hip flexor
tendonitis
• Treatment:
• Almost always nonoperative!
Snapping Hip
Syndrome
• External Snapping Hip:
Painful lateral hip pain from
ITB snapping over
trochanter
• Internal Snapping Hip:
Painful anterior hip pain
caused by iliopsoas tendon
snapping over the front of
the hip joint
• Reproduced by going from
flexion to extension or frog
leg position
Snapping Hip
Syndrome
• Treatment
• Physical Therapy
• Injections
• Surgery
SCFE
• Slipped Capital Femoral
Epiphysis
• Affects kids with open growth
plates
• Age range 9 – 14
• “The ice cream falls off the
cone”
• Anterior hip pain, limping,
inability to walk
• Often times can also have just
knee pain!
• Surgical emergency!
Stress fracture
• Femoral neck stress fracture
• Another surgical emergency!
• Typically another overuse
injury causing anterior hip
pain, limping, and/or
inability to walk
• Females > Males
• May be seen with Female
Athlete Triad
• Disordered eating
• Amenorrhea
• Osteoporosis
Stress fracture
• Three types
• Compression side
• Stable pattern
• Can be treated without
surgery
• Non-weight bearing
• Tension side
• Unstable pattern, usually
will progress
• Needs surgery
• Displaced
• Surgery
• High chance for AVN!
Stress fracture
Hip Labral Tears
• Hip labrum is a gasket that
goes around the hip socket
• Helps to provide some
stability
• Helps to seal the joint fluid
in place
• Some say also has
proprioception properties.
• Much like a regular gasket it
can wear down or tear
causing pain.
Hip Labral Tears
Hip Labral tear –
Why?
Hip Labral Tear
• Treatment options
• Not all labral tears require
surgery!
• Over-diagnosed.
• Must correlate with history.
• As you can see, many other
diagnoses of hip pain
• We went down this road in
the shoulder with SLAP
tears.
Hip Labral Tear
• Treatment options
• Physical Therapy
• Hip injections
• Surgery
Hip Labral Tear
Summary of Hip Pain
Knee Biomechanics
Where do we start?
Back to Anatomy
• Bony Anatomy
• Patella, Trochlea
• MFC, LFC
• Tibial plateau
• Cartilage
• Cartilage surfaces
• Meniscus
• Ligaments
• ACL, PCL
• MCL, LCL
• Patella, Quad Tendon
• MPFL
Back to Anatomy
• Muscles
•
•
•
Quad Tendon
• VMO, VLO
• Rectus Femoris
• Vastus Intermedius
Hamstring
Gastrocnemius
• We will then talk about very
common knee injuries
•
•
•
•
ACL
Patellar Dislocation
Meniscal Injuries
Cartilage Injuries
Knee Bony Anatomy
AP
Knee Bony Anatomy
PA
Knee Bony Anatomy
Lateral
Knee Bony Anatomy
Merchant
Knee Bony Anatomy
AP
PA
Femur
Fibula
Tibia
Growth Plate
Knee Bony Anatomy
Joint Space
Knee Bony Anatomy
Just for comparison…
Knee Bony Anatomy
Lateral
Femur
Patella
Merchant
Patella
Tibial Tubercle
Fibula
Tibia
Trochlea
Knee Cartilage
• Two types
• Articular Cartilage – found
on the ends of the bone
• Meniscal Cartilage – found
in between the bones
Knee Cartilage
• When cartilage forms it is
typically called hyaline
cartilage
• Made up of Type II
Collagen
• Very organized structure
• Readily able to withstand
compressive, loading, and
shearing forces
Hyaline Cartilage
Knee Cartilage
• When we have an injury to
our cartilage, it typically
forms Fibrocartilage
• Type I Collagen
• Softer structure than regular
cartilage
• Disorganized
• Not able to withstand
compressive and/or shear
stresses too well
Fibrocartilage
Knee Cartilage
Hyaline vs Fibrocartilage
Normal
Normal
Normal
Abnormal
Knee Cartilage
Hyaline vs Fibrocartilage
Knee Cartilage
• What is cartilage made of ?
• Cartilage Cells – 5%
• Matrix – 15%
• Water!! – 80%
• Adds lubrication
• Adds shock absorption
Knee Cartilage
Knee Cartilage
• Cartilage is amazing
structure. It basically allows
us to function at peak
performance levels
• But it does NOT repair itself!
• Cells lose ability to replicate
after age 20!
• One cell type only
• No blood supply
• No nerve supply
• Cells are low in density
• Chondrocytes cannot move
from one area to another
Knee Cartilage
Meniscus
• Meniscus acts like a shock
on a car – absorbs loads and
cushions the ends of the
bone
• Takes compressive load and
coverts it to hoop stresses
• Also helps with joint
stability and lubrication
• But…
• Prone to injury because of
the high loads it sustains and
poor blood supply
Meniscus
Knee Ligaments
• The main ligaments in the
knee are:
Knee Ligaments
Knee Ligaments
• ACL
• Central portion of the knee
• Main stabilizer to prevent
the tibia (shin bone) from
moving forward
• Also helps with rotational
stability (cutting and
pivoting)
• >100,000 ACL surgeries
done each year
• Lots of research on ligament
– still don’t quite understand
its nuances
Knee Ligaments
• PCL
•
•
•
•
•
•
•
Also central part of knee
Main stabilizer to the shin
bone moving backwards
Injured less often but when
injured may signify worse
knee injury
Injured with front to back
force on knee
Reconstructions can be done
but outcomes are not as good
as ACL
Tougher to return to high level
sport
Much to still learn on
ligament
Knee Ligaments
• MCL
• Ligament on inside of knee
• Easily injured
• Helps to prevent knee from
buckling inward – valgus
stress
• 3 types of injury
• Grade I – “tweak”
• Grade II – stretch
• Grade III – complete tear
• Most of time 10 – 14 days
recovery with Grade I
• Higher levels may require 6
– 8 weeks recovery
Knee Ligaments
• LCL
• Attaches on outside part of
knee – femur to fibula
• Prevents the knee from
buckling outward (varus
stress)
• Many times when injured, it
also pulls off a chunk of the
fibular bone
• Typically needs
reconstruction if completely
torn
Knee Muscles
• Quadriceps
• Hamstrings
• Gastrocnemius
• All play very important roles
• Probably most important is
quad muscle and its relation
to knee rehabilitation and
function.
• Quad controls patella
ACL Tears
Acl Tears
• Devastating injury
• Season ending injury
• ACL tears along with possible
associated cartilage and
meniscal pathology
• Mechanism of injury
•
•
Non-contact
Contact
• Why?
•
•
Still don’t know?
Risk factors…
Non-Contact
ACL Tears
• Risk Factors
• Women > Men
• Landing techniques
• Notch width
• ? Ligamentous laxity
• Fatigue
• Don’t know!!
A-Type Notch
ACL Tears
• Risk Factors
• Women > Men
• Landing techniques
• Notch width
• ? Ligamentous laxity
• Fatigue
• Don’t know!!
ACL Reconstruction
Widen notch
ACL Reconstruction
Identify angle to drill
tunnel in femur
ACL Reconstruction
Drill Femoral Tunnel
ACL Reconstruction
Drill Tibial Tunnel
ACL Reconstruction
ACL Reconstruction
Patellar Dislocation
• Similar to ACL with contact
vs non-contact type injuries
• Contact – wrong place at
wrong time
• Non-contact – predisposed
• Flat feet
• Poor landing mechanics
• Shallow anatomy for
patella groove
Patellar Dislocation
• Similar to ACL with contact
vs non-contact type injuries
• Contact – wrong place at
wrong time
• Non-contact – predisposed
• Flat feet
• Poor landing mechanics
• Shallow anatomy for
patella groove
Fulkerson Osteotomy
Fulkerson Osteotomy
Fulkerson Osteotomy
Fulkerson Osteotomy
Meniscal Tears
Meniscal Tears
Meniscal Tears
Cartilage Repair
Cartilage Repair
Cartilage Repair
Ankle Biomechanics
Ankle Anatomy
• 3 bone articulation
• Mortise held by four
syndesmotic ligaments and
interosseous membrane
• Medial malleous
• superficial/deep deltoid
Tibia
• Fibula (LCL complex)
• Anterior talofibular ligament
• Calcaneofibular ligament
• Posterior talofibular
ligament
Talus
Fibula
Ankle Anatomy
• 3 bone articulation
• Mortise held by four
syndesmotic ligaments and
interosseous membrane
• Medial malleous
• Superficial/deep deltoid
• Fibula (LCL complex)
• Anterior talofibular ligament
• Calcaneofibular ligament
• Posterior talofibular
ligament
Mortise
Ankle Anatomy
Ankle Anatomy
• On medial malleolus is the
Deltoid ligament complex
• Superficial Fibers
• Make a triangle
• Deep Fibers
• More transverse
• Deltoid ligament is primary
medial ankle stabilizer
Medial Malleolus
Ankle Anatomy
• Lateral malleolus
• ATFL, CFL, PTFL
• Calcaneofibular
ligament strongest
lateral ligament
• Resists posterior
translation
• Anterior talofibular
• Resists anterior
translation
Lateral Malleolus
Ankle Anatomy
• Tibiofibular syndesmosis complex
• IOL: thickening of interosseous membrane
• AITFL
• PITFL
• ITL
• “Third malleolus” – trimalleolar fracture
Ankle Anatomy
Ankle Anatomy
Outside of Ankle (Lateral)
Inside of Ankle (Medial)
Retinacular Structures that hold tendons in place
Ankle Motion
• Motion not true
hinge joint
• Talus wider
anteriorly than
posteriorly
• Allows increased
stability in
dorsiflexion
Frustrum of cone
Physical
Examination
• History
• How, when, where; preexisting function; medical
condition
• Be specific!
• Inspect/palpate circumfrentially
Physical
Examination
•
Neurovascular exam:
Imaging – X-rays
• AP – front view
• Lateral – side view
• Mortise view
• Internally rotate leg
Xrays
Ankle Injuries -Fracture
• Very common ankle injury
• Not all require surgery
• We talk about the fractures
in terms of how many
Malleoli they affect
• Bimalleolar
• Trimalleolar
• Isolated lateral or medial
malleolus
Ankle Injuries -Fracture
Ankle Injuries -- Fracture
• Isolated Lateral Malleolar
Fractures
• R/O medial sided and
syndesmotic injury (PE, xray)
• ? Need for stress views
• If no medial injury then:
• Can treat with protected
weightbearing in walking
cast/brace
• Biomechanics
• Medial stability, intact
ligaments prevent lateral
shift of mortise
Ankle Injuries -- Fracture
Thank You!!
• What have I missed?
• Anything else you would like
covered?
• General questions…
James Bicos, MD
248-988-8085
[email protected]
www.performanceorthopedics.com
@prformanceortho