The reduction in neck mobility exposes the capsules, fibrous bags around the joints, of the facet joints to traumatic stretching events. Turning the neck suddenly without conscious thought can push the joints to the limits of their movements, injuring the fibres of the capsular ligamentous tissues. This produces joint pain and scarring with increased capsular tightness as the healing process proceeds, making the joints tighter and less willing again to tolerate stresses. As the tight joints can occur in several parts of the neck this can cause a limitation of joint motion which doesn't become apparent until one day you find you can't turn your neck as you expect to.
The pain sources from facet joint arthropathy are due to various reasons: the local musculature responds to pain by developing muscle spasm; the local facet joint is suffering from pathological changes and there is referred pain. Localised neck pain, the centre of which is often identifiable by feeling with the fingers, comes from the irritated facet itself while the referred pain is much less clear in nature, expressing itself as a vaguer general feeling of ache in the arm or shoulder. As the neck problems increase it can interfere with important abilities such as sleeping which can lead to side effects such as depression and anxiety.
Acute wry neck is a sudden onset painful injury to the facet joint, perhaps resulting from a sudden movement such as looking quickly to one side, suffering a jar or drying ones hair vigorously. We can wake up with this problem also, having presumably slept at an odd angle for a persistent length of time. This problem usually presents as a sudden facet joint lock from an unplanned movement as the stabilising and moving muscular controls are caught off guard, perhaps straining the sensitive capsule or trapping a small fold of synovial membrane. The severe pain which results causes intense muscular spasm which clamps the neck rigid and adds the pain.
The result for the patient of an acute wry neck is usually a severe, mostly one-sided neck pain and significant limitation of movements. Muscle spasm may be very severe and the head may be held at an unusual angle or part way into a movement to one side. The person guards their movements very carefully and moves slowly, desperately trying to avoid a sudden movement which will cause an increase in the compressive forces of muscle spasm and so the severe pain. Getting into bed at night or getting up in the morning can be very difficult with holding the head with the hands to cope as the muscles attempt to stabilise the neck.
A locked neck joint can be unlocked, sometimes very quickly and with complete relief, by cervical manipulation from a manipulative physiotherapist, chiropractor or osteopath, with the mechanism thought to be un-trapping of the nipped tissues by gapping which could also allow the joint to realign itself. This is less common that the normal recovery which takes place over a few days with painkilling and anti-inflammatory drugs until the neck begins to move more normally again. Therapists can also employ a repeated therapy called joint mobilisations which helps to restore normal movements to the joint and prevent recurrence.
A fast onset of neck pain is not always due to facet lock but can, with a gradual onset taking several days, be indicative of a disc related or inflammation related nerve root insult. An initial facet joint injury may in some cases not settle down well, allowing fluid to collect around the nerve root exit from the spinal canal which slowly thickens and forms into scar tissue and can stick down the nerve to the surrounding structures. Tethering the nerve exposes it to risk of injury due to the fact that nerves are very sensitive to stretch in particular, which can result in an agonising pain syndrome developing in the shoulder, arm and neck.
Although neck pain may not be the major presenting part of the problem, patients often indicate there were some warning signs from their neck previously, with the neck or arm being less predictable and reliable on various activities. The precipitating reason for the full syndrome may be something small, just in the right direction to stress the nerve.
