- February 29, 2016
- By Dr Jock Mackenzie
- 0 comments
Arkless v Betsi Cadwaladr: failure to diagnose scaphoid fracture
In a recent case, Arkless v Betsi Cadwaladr University Local Health Board, the High Court determined liability relating to a scaphoid fracture. The importance of this case is that doctors are taught when they are medical students that scaphoid fractures are injuries that it is absolutely critical not to miss.
The scaphoid bone is one of eight small bones that make up the “carpal bones” of the wrist and is typically injured when one falls forwards onto an outstretched hand, with the wrist in hyperextension and with the weight landing on the palm. Such injuries are very typically sporting injuries.
The critical aspect of such a fracture is that the arterial blood supply to the bone runs from the proximal part (closest to the forearm) to the distal part (closest to the fingers) and a fracture across the bone (across the scaphoid “waist” or at the “proximal pole”) may interrupt that supply. As a result of such a fracture, the distal part of the bone may then end up without a blood supply unless it is rapidly identified and treated (e.g. with a pin); if it is not, then the bone may begin to die due to “avascular necrosis”, resulting in severe permanent injury and disability and requiring a bone graft.
Such is the importance of these fractures that the College of Emergency Medicine in September 2013 published guidelines which set out in terms exactly how to examine a wrist for a suspected scaphoid fracture. One of the key aspects of the examination, again which is taught as early as medical school, is tenderness in the anatomical snuff box (ASB), the small depressed area at the angle of the base of the thumb and forefinger. There are two other tests, tenderness of the scaphoid tubercle (ST) and axial (loading) compression of the thumb (LC), both of which are also used to determine the possibility of such a fracture. A medical paper published (by Carpenter and others) in February 2014 performed a “meta-analysis” of some of the medical literature on the reliability of various clinical tests in detecting scaphoid fractures, and found that the ASB test was 96% positive in patients who did have a scaphoid fracture (“sensitive”), the ST test 92% sensitive whereas the LC test was 82% sensitive. Additionally, it is important to carry out an x-ray with specific scaphoid views, taken in the correct planes to view the scaphoid properly, and to review in about 7-10 days after the injury, as it can take this amount of time for an “occult” fracture to become apparent.
In this particular case, the facts were quite straightforward. The claimant was a goalkeeper and she injured her wrist playing football in April 2009. She attended A&E and was seen by a triage nurse, who recorded her hyperextension injury with subsequent pins and needles and limited range of movement. She then saw Dr Atkins, the Casualty officer, who in evidence described how he would normally examine a scaphoid using the tests described above (although he could not remember this case specifically) although his description merged the ASB and the ST test into one test. He documented at the time that the ASB test was non-tender and the LC test elicited no pain. He arranged for an x-ray; however, the x-ray did not specifically target the scaphoid with “full scaphoid views”, Dr Atkins stating subsequently that this was because he had not elicited any scaphoid tenderness. Dr Atkins concluded the x-rays were normal and prescribed a splint. The claimant’s evidence was that she not told that she should return if her wrist worsened and the judge believed her, describing her as “an entirely credible historian”.
By early 2010, her wrist was so bad that she re-attended A&E and x-rays and an MRI confirmed a scaphoid fracture which had not healed such that she would need a bone graft from her hip. She underwent this, unsuccessfully, and at the time of trial still needed further surgery. Damages had, however, been agreed between the parties in the sum of £39,000.
Both parties’ breach of duty A&E experts had some misgivings about Dr Atkins’ merged ASB/ST test and agreed that they had never been taught, and did not teach, that particular test. They disagreed on whether it was acceptable, however. Both parties’ hand surgeons agreed that, if proper scaphoid examination had been carried out, tenderness in the ASB would have been elicited.
The judge concluded that reasonable medical practice for the examination of a possible scaphoid fracture must include examination of all 3 tests: ASB, ST and LC. The number of patients with a fracture who would not be picked up by these tests being performed properly was vanishingly small. He concluded that, on the evidence, Dr Atkins had not performed a competent examination on the basis that it appeared that he had not carried out the ST test; he had erroneously rolled up the ASB and ST tests into one; and, finally, if the tests had been performed properly, on balance, tenderness would have been elicited. The claimant, therefore, succeeded.
The case underlines for doctors the importance of examining fully and properly, with the three tried and tested techniques that almost certainly will elicit tenderness in the presence of a scaphoid fracture, and, importantly, documenting that these three tests have been performed and their results. For patients, it is essential that they are confident that the doctor has carried out these 3 tests properly, proper x-ray scaphoid views have been taken and appropriate follow-up has been arranged.