Facet joints Flashcards
what is a facet joint?
synovial plane joint
what is a facet joint also known as?
a zygapophyseal, or apophyseal, joint
what does a facet joint contain?
Contains joint capsule and membrane which helps produce synovial fluid which aids in facet joint movement
how many facets are there at each spinal level?
2 facets
where are the facet joints?
Between the inferior articular process from vertebra above and the superior articular process form vertebra below
Located in posterior portion of individual vertebra
what do the facet joints contribute to?
the motion segment of the spine, along with the intervertebral disc, which helps protect, stabilise and limit movement of the spine.
facet joints help what?
help guide movement of the segment and help transmit spinal loads
what are the facet joints covered in?
hyaline cartilage
each facet is enclosed in what?
within a thin fibrous capsule lined with a synovial membrane – this capsule can aid or limit movements within different vertebral levels
what allows stretching without injury in relation to the joint capsule?
crimped collagen fibres
shape of the articular processes help determine what?
the movement each facet joint will allow – differs at each vertebral level
the joint capsule prevents what?
friction during movement
what does the literature say about joint capsules?
capsule is innervated by fine nerve fibres which may produce nociceptive and proprioceptive sensations
the capsular ligaments helps reinforce what?
ligament helps reinforce the facet capsule and helps to limit motions of the facet joint
what is the capsular ligaments composed of?
collagen fibres which extend between the vertebrae and connect to the ligamentum flavum
capsular ligament encloses what?
the joint
what are meniscoids?
Invaginations of synovial membrane that can vary in shape
where are the meniscoids attached to?
Attached to the joint capsule peripherally, at dorsal and ventral poles, and extend towards the centre of the joint
what are meniscoids made up of?
Composition of adipose tissue, loose and connective tissue with collagen fibres that extend through the structure
meniscoids are hypothesised to do what?
to distribute heavy loads over a larger surface area, allowing smoother gliding motions during joint movement
Facet joints are innervated by what?
medial branches of the dorsal rami – much research has been performed on how to eliminate pain from the facet joints using these medial branches – nerve blocks, injections etc….
what are the arteries involved with the vertebrae?
Cervical- vertebral and ascending cervical arteries
Thoracic- costocervical and posterior intercostal arteries
Lumbar- lumbar and iliolumbar arteries
Sacral- lateral sacral arteries
what are the veins involved with the vertebrae?
Intervertebral veins which form plexuses
what is the structure of the superior facets of the atlas?
upward and medial, concave, anterior ends nearest midline
what is the structure of the inferior facets of the atlas?
concave but looks flat, oval
the concavity of the atlas does what?
prevents ‘no’ movement
what are the variations of the atlas?
Concavity
Unsymmetrical
Constrictions (45% of 200 vertebrae)
what is the structure of the superior facet of the axis?
oval, inclined obliquely downwards posteriorly, face laterally
what is the structure of the inferior facet of the axis?
face more anteriorly to articulate with C3
‘no’ movement at the atlantoaxial joint of the axis is permitted by what?
permitted by relatively flat and tilted facets
what is the structure of the superior facet of the lower cervical (C3-7)?
flat, face posteromedially
what is the structure of the inferior facet of the lower cervical (C3-7)?
face anterolaterally
facets in the lower cervical region allow what?
for greater range of movement in this region – flexion, extension, rotation, lateral bending
Oblique- 45’ from the horizontal plane
what is the structure of the capsule in the lower cervical region?
The capsule is particularly lax in the cervical region to allow gliding of vertebrae
what degree of flexion can occur in the lower cervical region and what occurs to the facets?
(25’)- superior facets slide up and tilt forward (capsule widens posteriorly, no bony limitations- subluxation)
what degree of extension can occur in the lower cervical region and what occurs to the facets?
(85’)- superior facets tilt and slides posteriorly, IV space closes, gap opens anteriorly
what degree of lax flexion can occur in the lower cervical region and what occurs to the facets?
(40’)- gliding up and down but also back and forward due to orientation of facets, so always accompanied by rotation
what degree of rotation can occur in the lower cervical region and what occurs to the facets?
(50o)- occurs with lateral flexion, prevented by grinding of opposite facets together, opens capsule in direction of head rotation
what is the structure of the articular processes in the thoracic region?
thin, triangular
where do the superior articular facets face in the thoracic region?
posterolateral
where do the inferior articular facets face in the thoracic region?
anteromedial
where do the facets sit in the thoracic region in relation to the horizontal and axial plane?
60’ horizontal abd 20’ axial
what kind of arrangement are the facets in the thoracic region?
circumferential
what degree of flexion can occur in the thoracic region and what occurs to the facets?
freer in lower T region because they’re more flexible (longer cartilage and floating ribs), limited by ribs and ligaments
what degree of extension can occur in the thoracic region and what occurs to the facets?
limited by impact of articular processes
what degree of lat flexion can occur in the thoracic region and what occurs to the facets?
20-25o)- freer lower half, contralateral facet moves like flexion and other moves like extension, limited by articular processes, also rotate (1o for 1o)
what degree of rotation can occur in the thoracic region and what occurs to the facets?
(35o)- articulations made for rotation, articular processes slide away from other processes, lost when fully extended- important during walking to keep head facing forward (T7/8 no rotation but above and below have the most)
what is the structure of the articular processes in the lumbar region?
strong
what is the structure of the superior facets in the lumbar region?
concave, medially and backward facing
what is the structure of the inferior facets in the lumbar region?
convex, forward facing and slightly lateral
Literature suggests that the joint capsules in the lumbar regions are what?
more taut and smaller in comparison to the cervical region which helps limit rotational movements in the spine
what movement can occur in the lumbar region?
Flexion, extension, lateral flexion, no rotation
what degree of flexion can occur in the lumbar region ?
(55’)- inferior facets glide upwards and forwards on superior facets
what degree of extension can occur in the lumbar region ?
(30’)- superior facets glide down into the inferior facets and tilt backwards,
what degree of lateral bending can occur in the lumbar region ?
(20’-30’, 60’ in children)- very little lateral bending and therefore no rotation, one side becomes close packed and the other separates and gap forms
shape of surfaces in the lumbar regions restrict what?
restrict rotation (couple of degrees)- increases with flexion and decreases with extension. Small gaps between facets become obliterated with rotation and prevents any more rotation
are there facets between the sacral bones?
no as they are fused together
where are the lumbosacral facet joints?
Between inferior facets of L5 and sacrum
the L5 facets face where?
anteromedially
the sacrum facets face where?
posteriomedially
Iliolumbar ligaments attach where?
attach from the transverse processes of L5 to the ilia
main movements of the sacral facets are what?
flexion and extension
total range of movement of the sacral facets is what?
18’
what is movement of the sacral facets limited by?
iliolumbar ligaments
in relation to the sacral facet lateral flexion decreases from what to what?
decreases from 7’ in children to 1’ in adults
Orientation of facets and ligaments prevent what?
anterior gliding of the lumbar vertebrae
the coccyx consists of what?
fused bones
do the coccyx vertebrae have articular processes or facets?
no
what kind of joint is in the coccyx?
second cartilagenous
The facet joint aids the IV disc in what?
in stabilising the spine and supporting spinal motion
Weight can bear down and transfer to the facet joints when?
especially when the spine is in motion to produce movements such as rotation
With repeated weight bearing loads does what to the facet joint and can lead to what?
the facet joint cant deteriorate over time/ age, This can lead to facet degeneration which can lead to disorders such as facet joint syndrome and osteoarthritis
Up to 25% of compression through facets, torsional stiffness, prevent what?
translation
what is whiplash?
is an acceleration-deceleration mechanism of energy transfer to the neck. It may result from rear end or side impact motor vehicle collisions, but can also occur during diving or other mishaps. The impact may result in bony or soft-tissue injuries (whiplash injury), which may lead to a variety of clinical manifestations.” (Quebec Task Force)
What causes symptoms?
Facet joint degeneration after injury
what are the most common injury associated with road traffic accidents (RTA)?
Whiplash associated disorders (WAD)
what movements occur during whiplash?
Cervical spine movements during whiplash
WAD graded 0-4: symptoms include what?
neck stiffness, pain, headache, upper limb pain, paraesthesia
Acute/ subacute- symptoms last how long?
< 3 months
Chronic- symptoms last how long?
> 3 months (40% patients are chronic)
what is stage 1 of whiplash?
cervical lordosis is lost so there is a flexion deformity of upper and lower C-spine
Force- tensile (<50ms)
what is stage 2 of whiplash?
‘S’ shape forms- lower vertebrae extend while upper vertebrae flex
Force- shear, tensile and compressive (50-75ms)
what is stage 3 of whiplash?
extension at both ends of the C-spine
Force- shear and tensile (75-100ms)
what is stage 4 of whiplash?
hyperflexion
Force- shear and tensile (>100ms)
when is most damage caused during whiplash?
stage 2, between C5/6 posteriorly
lax ligaments allow what?
gliding of vertebrae
what state are the muscles in before whiplash?
Usually an unexpected event so muscles are relaxed too
Most stretch occurs where?
anteriorly; most compression occurs posteriorly
During flexion there is no bony limitations in the cervical region which can lead to what?
can lead to dislocations
what is synovitis?
Inflammation and damage to the capsule
what is Capsule ligament stretch?
Mechanical stimuli causes hyperexcitability of capsular afferents
Poor healing abilities of ligaments leaves patient with chronic pain
Increased instability of facet joints could lead to further damage- facet subluxation
what is Nerve and meniscoid impingement?
Articular facets collide and cause meniscoid impingement
Spinal nerves trapped in intervertebral foramen in extension phase
what is degenerative changes?
Articular facets wear away from years of poor congruency
May end up with osteoarthritis
what percentage of over 70s have FJD- ageing is a risk factor?
75%
Injury to a joint increases what?
the likelihood of degenerative disease
symptoms of facet joint degeneration after whiplash?
stiffness, pain
No correlation between symptom severity and x-ray findings
diagnosis of facet joint degeneration after whiplash?
accident + symptoms
Only x-ray if there are red flags (eg neurological impairment)
X-rays show a lot of false positives in the acute phase
Can sometimes see loss of lordosis, subluxation and fractures
management of facet joint degeneration after whiplash?
Early mobilisation (in the past, collars were used) NSAIDs Steroid and anaesthetic facet joint injections not given on the NHS
