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.
Facet arthropathy causes pain from several sources: the local pain from the abnormal facet joint itself; referred pain from this source and the resulting muscle spasm. The joint pain itself is fairly closely localised and may sometimes be felt by one’s own fingers as a tight lump. Referred pain is often felt as an ache which is difficult to clearly define, its just an annoyingly vague but troubling pain in the arm, shoulder or thoracic area. These symptoms can eventually become important and disturb sleep, which has knock-on effects such as tiredness, irritability, increased muscle tenderness, anxiety and depression.
Turning the neck suddenly, being jarred unexpectedly or towelling the hair vigorously can result in a sudden onset of severe neck pain and loss of movement, a condition referred to as acute wry neck. People can also awake with the same kind of problem, perhaps because they have slept awkwardly and strained the neck. The facet joint locks instantly as the speed and unexpectedness of the activity bypasses our control and stability mechanisms. The sensitive capsular joint surround might be strained in these events or the joint could pinch a synovial membrane fold, resulting in instant, severe pain in the neck and limiting muscle spasm.
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 facet joint lock episode is not the only possible reason for the sudden or a slower onset of neck pain as this can also be caused by a prolapsed disc or inflammatory insult to the nerve. If an original locking injury to the facet joint does not recover well or completely then the nerve root exiting through the narrow foramen can be surrounded by an inflammatory fluid which can gradually thicken into fibrous tissue. This can tether the nerve and if the nerve then suffers a quick stretch, which nerves are especially bad at tolerating, it can set up a very unpleasant syndrome with severe arm, shoulder and neck pain.
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.
