The axial skeleton Flashcards
Clinical examination of the axial skeleton
start with neck palpation and baited stretches
Move caudally along the axial skeleton
Deep, sustained pressure onto the epaxial muscles of the thoracic and lumbar spine. Can apply pulsatile pressure to assess ability to ventral flex.
Assess – muscle mass, muscle tone, symmetry and pain on palpation
Epaxial muscles
Muscles above the ribs/transverse processes
Responsible for spinal stability and lateral flexion
Longissimus, multifidus
Sternal lift
sustained pressure applied to the sternum to encourage dorsiflexion of the cranial thoracic spine
Abnormalities you might see with a sternal lift
Lack of response
Transient response that cannot be maintained
Overt objection to dorsiflexion – watch out!!
Abnormal responses to palpation of the sacroiliac region - either side of the midline
Horses with discomfort in this region often “shrink” towards the floor and hyperextend the region
Some horses show a marked pain response and can kick out
How do you achieve lumbosacral dorsiflexion in a horse?
Apply pressure to the skin either side of the tail base
Horse should dorsiflex lumbar spine and lumbosacral joint
Drop tuber ischii towards the floor
Remain relaxed
Abnormal responses to lumbosacral dorsiflexion pressure
No response
Unable to maintain the flexion for more than a few seconds
Outward signs of pain or discomfort
How many cervical vertebrae are there?
7
What are the main manifestations of cervical disease?
Neck pain/dysfunction
Forelimb lameness
Ataxia - cervical stenotic myelopathy
Signs of neck pain
Reduced range of motion during baited stretches
Changes in position or posture
Palpation findings – enlarged joints
Reduction in muscle mass
Two mains mechanisms of forelimb lameness
A consequence of muscle dysfunction
Radiculopathy - neuropathic pain
Muscle dysfunction
Many cervical muscles are involved in protraction of the forelimb
Brachiocephalicus – changes in strength or function can cause asymmetry
Reticulopathy - neuropathic pain
Compression of a spinal nerve root in the caudal cervical region (feeding brachial plexus)
Enlarged APJs are the culprit
Diagnostic imaging of the cervical spine
Radiography is the most common first line but its lacks diagnostic acuity.
CT is the only 3D imaging modality that can accommodate the equine neck!
- often combined with diagnostic accuracy
Treatment of pain in the cervical spine
Intra-articular medication with corticosteroids is the mainstay
Cannot reverse bone remodeling but can alleviate pain and reduce associated soft tissue inflammation
There are no landmarks on the surface, and the target is deep beneath muscle…
Injections are performed under ultrasound guidance.
Prognosis of cervical spine pain
Variable and often unpredictable
Neck pain > radiculopathy > spinal ataxia
Clinical signs of thoracolumbar disease
Poor muscling
Pain on palpation
Abnormal dynamic responses
Resentment of ridden exercise
Poor quality canter (vs trot)
Radiography of thoracolumbar spine
Laterolateral views are most commonly acquired and are excellent for disease affecting the dorsal spinous processes.
CARE – you can find dorsal spinous process disease in a large proportion of horses with no back pain!!
Other imaging modalities of thoracolumbar spine
Gamma scintigraphy (bone scan)
- inject a bisphosphonate
Response to local anaesthesia
Response to local anti-inflammatories
Treatment of thoracolumbar spine
Medical management and rehabilitation is probably the starting point for most cases:
- Local injection of corticosteroids
- Rehabilitation program to restore strength and function
This can be curative in some cases, can be repeated in cases with good responses.
Frequency of injection often reduces with time as they become stronger.
Surgical management of thoracolumbar spine pain
Interspinous ligament desmotomy
Subtotal (cranial wedge)
Interspinous ligament desmotomy
To help with thoracolumbar spinal pain
Cutting the interspinous ligament
Disadvantage: Doesnt change the underlying anatomy
Advantage: short rehab period
Disadvantages of a subtotal (cranial wedge) ostectomy
Invasive procedure
Post-operative pain
Long rehabilitation period - up to 6mo for owners so may not be possible for everyone
Advantages of subtotal (cranial wedge) ostectomy
Permanent anatomy change
Better long term outcomes
