Whiplash is a common injury to the neck, caused by a forceful and rapid movement of the neck back and forth. There are three common causes of whiplash in the UK: road traffic accidents, assaults and rugby injuries. In Bannister et al’s paper, it was estimated in 2009 to be costing the UK £3.64 billion, and whiplash made up 3/4 of all motor vehicle insurance claims.
Patients presenting with whiplash can complain about numerous symptoms such as neck pain, stiffness, upper shoulder pain, and headaches. Patients may go on to develop sleep disturbances as a result of the injury, headaches, and tinnitus.
Fortunately, most whiplash victims will recover within a couple of weeks. It is felt that the outcome can be predicted by three months in 70% of patients. The most common cause of a whiplash claim is a rear-end shunt, and the speed is less than 14 mph in 90% of claims.
The injury mechanism is felt to be a hyperextension of the neck, which then recoils forward. There are factors that can increase the displacement of the neck, including being female and the size of the vehicle. Women are twice as likely to sustain a whiplash injury, potentially due to their thinner and more mobile neck. The position of the headrest is key, with accidents reporting that 3/4 of headrests were fitted incorrectly. This can then create a fulcrum that the neck moves around, increasing the forces if the headrest is too low.
Presentation to Accident and Emergency
Studies have looked at the timing of presentation to accident and emergency. The vast majority present with onset of pain within 12 hours, and almost all report pain presenting within 24 hours. Those presenting to ED account for 1/3 of patients. 2/3 of women have to take time off work following a rear-end shunt.
Symptoms of whiplash
The most common symptoms are neck pain and stiffness. Other common complaints include occipital headaches, thoracolumbar back pain, and paraesthesia in the upper limbs. Up to 10% may develop sub-acromial impingement. Regarding prognostic factors, the longer the symptoms persist, the worse the outcome. In all claims, around 2% may be classified as disabled due to their symptoms Overall 88% of patients are symptom-free at two months, with 93% free at three months. Most improvement occurs during the first year with minimal improvement after 12 months noted.
Neck pain can be constitutional and 14% of the British population have chronic neck pain. Studies have suggested that most people associate their neck pain with trauma. Around 40% of the population will develop neck pain in their adult life.
Other factors found to be associated with a poor outcome are old age, lower educational achievement, part-time work, pre-existing neck and low back pain and previous whiplash injury. Clerical workers made a swifter return to work than manual workers and self-employed individuals took less time off but longer to recover than the employed.
Radiology has been found to have an impact on recovery. Those patients with wear and tear changes in their necks had a higher incidence of ongoing pain at two years. Radiological degeneration at C5/C6 was twice as common in symptomatic whiplash patients. MRI scans have not been found to be useful in the diagnosis of whiplash. One study by Watkinson et al has suggested that late degenerative change with neck symptoms may be associated with previous whiplash. Parmar et al found that patients who suffered a whiplash injury in their third decade had degenerative changes more advanced by 15 years 10 years later.
A study by a Norwegian neurologist in Lithuania found the maximum duration of whiplash symptoms was 20 days. This differed from a study in Finland, which found that the most common symptom a year after a whiplash injury was neck pain with headaches.
Interestingly, in the 1980s a study comparing the New Zealand and Australia populations found that the Australians who have a tort system had more rear-end collisions reported, 10 times the number of compensation claims and five times as many claimants for work. In 1987 there was a law change in Victoria requiring the first $317 AUD to be paid by the claimant in a whiplash case. This corresponded with a 68% fall in claims. Interestingly, there was still 10% of Australians who had chronic pain after this from whiplash claims.
How is whiplash treated?
Most whiplash cases settle with little more than rest and painkillers. This means that simple painkillers such as ibuprofen or paracetamol can help improve the pain in these patients. Other simple treatments could be ice packs and muscle rubs. It is also recommended that you continue doing your usual daily activities within the comfort of pain. For most, this is all that is required.
Soft collars have been found to be less effective than normal activity and physiotherapy. There has been some research into facet blocks which found that 50% of symptoms returned within a week suggesting little benefit. Of those patients who undergo shoulder surgery, there is only 50% that report an improvement. Late treatment has been found to be relatively ineffective for whiplash.
With any accident, there needs to be consideration of the psychological impact. This can be difficult for the orthopaedic expert witness to quantify. Factors such as how long the patient could not drive and if they have had any intrusive thoughts about the accident are key. Where these are ongoing referral to a clinical psychologist for counselling and prognostics around the symptoms is best.
Medical reports in whiplash should be based on the evidence of the case. The presence of poor prognostic indicators such as previous neck pain, previous whiplash and psychological disturbance doubles the risk of chronic pain. Increased symptom duration is associated with neck stiffness early onset and severe pain. Most patients who have symptoms after three months will remain symptomatic despite later intervention.