Cervical Instability

Normal Anatomy Normal stability of any joint is made of 2 aspects – Static Stabilisers – osseous configuration, capsules and ligaments – Dynamic Stabilisers- muscle function through dynamic ligament tension, force couples, joint compression and/or neuromuscular control Approximately 50% of rotation occurs at C1/2 Ligaments provide the primary source of stability Vast amount of neurological and vascular structures

Atlantoaxial Joint Transverse Ligament of the Atlas

Atlantoaxial Joint Tectorial Membrane

Atlantoaxial Joint Alar Ligament and Transverse Ligament

Pathophysiology Excessive movement at the upper cervical spine Can be the result of bony fracture, ligamentous laxity or rupture or neuromuscular deficits Can result in pain, neurological or vascular compromise

Mechanism Of Injury Traumatic – Whiplash – Fractures, Dislocations – Surgery Systemic – Upper Respiratory Infection Congenital – Down Syndrome – RA – Os Odontoideum – Klippel-Feil Syndrome – Hypermobility Syndrome

Associated Pathologies Cervical Artery Dysfunction Cervical Myelopathy Cervicogenic Headaches

Subjective History of trauma or congenital/systemic disease Neck pain Intolerance to prolonged positions Feeling need to support the head Sharp pain or catch with movements

Subjective Signs of neurological or vascular compromise – Drop attacks – Facial or lip paraesthesia – Bilateral or quadrilateral symptoms – Nystagmus – Dizziness – Blurred vision – Metallic taste in mouth – Lump back of throat – Think neuro, think vascular, think cranial nerves, think CNS

Objective Based on Subjective History May not be appropriate in some cases Start with cranial nerve and BP testing

Objective Serious (Static Stability) Reduced sensation Reduced power Reflex changes Cranial Nerve Changes Significant muscle spasm Reluctance to move Non Serious (Neuromuscular) Sensorimotor changes – Smooth Pursuit Neck Torsion – Saccadic Eye Testing – Joint Position Error Full range of movement with painful stretching end of range Painful catch/ unsmooth movements Increased joint play

Special Tests Sharp Purser – Sitting relocation of C1 on C2 Alar Ligament Testing – Supine testing of rotation and lateral flexion of Upper Cx with fixation of C2 Transverse ligament Testing – Supine with fingers around patients head and between occiput and C2. Lift head and C1 anteriorly and hold for mins

Further Investigation MRI X-ray Open Mouth X-Ray

Management Referral to a specialist if signs of neurological or vascular compromise Conservative management for those with congenital or neuromuscular reasons for instability Surgery nearly always for traumatic instability

Conservative - Management Sensorimotor rehabilitation Cervical and scapular rehabilitation Manual Therapy to Thoracic Spine Acupuncture for pain relief

Surgical - Management Depends on pathology causing instability