Scaphoid injuries: pitfalls and pearls

The failure to diagnose scaphoid injuries is a common source of claims at Medical Protection. Dr Emma Green, medicolegal consultant at Medical Protection and emergency medicine doctor, advises on the common pitfalls and how to avoid them

Missed fractures can result in multiple adverse outcomes for patients. Often, causation issues in claims flow from delays in diagnosis, as earlier diagnosis allows for immobilisation or operative management in some fractures.

FOOSH (fall on outstretched hand) is the most common mechanism of scaphoid fracture although other mechanisms can include blunt scaphoid trauma as well as repeat stress type injury. These injuries can also be associated with radial fractures, especially in older populations, but unless a scaphoid injury is considered it is unlikely to be diagnosed.

Pitfall 1

Incorrectly interpreting the mechanism Injuries in sport, such as a goalkeeper saving a ball or any hyperextension injury with loading, can sometimes be misinterpreted in terms of mechanism, increasing the risk of missing a scaphoid fracture. Consider these in the same way as a direct FOOSH.

Examination should include the wrist, as radial fractures are also common with the same mechanism of injury. Additional tests should, however, be undertaken in relation to the scaphoid and documented clearly.

Special tests for scaphoid injury

• Tenderness over anatomical snuff box
• Tenderness over scaphoid tubercle
• Telescoping (hold thumb firmly and apply
pressure towards the metacarpal bones)
• Tenderness over scaphoid tubercle.

Clinical signs are not necessarily diagnostic

The above tests are reported to have high sensitivity but specificity of 9%, 30% and
48% respectively.¹ However, in reality, these signs are not always present despite competent examination even in early presentation.

In a study by Waizegger et al ² 12 clinical signs associated with scaphoid fracture were examined within three days of injury and again at two weeks. The study found a history of an extension injury, tenderness in the snuff box and pain elicited in the snuff box, with resisted supination, to be the most reliable clinical indicators of a recent scaphoid fracture. However, none of these findings were invariably present.

Many patients without a scaphoid fracture have identical signs and symptoms, so no test is completely reliable. This may assist in defending cases where clinical examination
has been documented but does not necessarily provide a robust defence. Expert
orthopaedic surgeons have commented that signs may also reduce after a time period due to healing with scar tissue.

Clinical records should contain sufficient information to show that the relevant history and examination were undertaken. The clinical examination should be sufficient to raise clinical suspicion of scaphoid injury.

Primary care

Patients are usually seen in the Emergency Department following injury, where they may be given a diagnosis of wrist sprain. Re-examination in primary care if a patient presents and has not had an x-ray may offer an opportunity to make a diagnosis. This can also be a chance to consider whether the appropriate imaging was done.

Pitfall 2: Wrist x-ray or scaphoid series?

A wrist x-ray is insufficient in suspected scaphoid injuries. Based on retrospective studies and cadaveric review, the most sensitive radiographic evaluation includes four views: PA, lateral, pronated oblique (60° pronated oblique) and ulnar deviated oblique (also described as 60° supinated oblique).³

Pitfall 3: Lag in radiologically visible fracture

Scaphoid fractures may take 7-14 days to be radiologically visible. Patients who have
only had one x-ray for suspected scaphoid fracture should be considered to have a
fracture until two negative x-rays or they have had a negative MRI scan, depending on
local policy.

Risks of missing a fracture

Avascular necrosis is a recognised complication associated with waist and proximal pole fractures. Non-union of scaphoid fractures can result in a need for bone grafting, which can impact the value of a claim and create the potential for ongoing symptoms from synovium inflammation and scarring. Scaphoid non-union advanced collapse is also associated with chronic nonunion where a non-union period of more than five years has a less favourable outcome.

Scaphoid claims: the medicolegal view

When considering the value of a scaphoid claim, case law examples below show that
the value can vary depending on longterm disability and outcome, but can be considered between £10,000 and £40,000 as a broad ballpark figure.

M v Royal United Hospital Bath NHS Trust (2010) where the claimant, a 31-year-old man, received £10,000 PSLA (pain, suffering and loss of amenity) for the alleged failure
to correctly diagnose and treat his scaphoid fracture for four months. He later had to
undergo percutaneous screw fixation and bone grafting surgery.

JK v Lancashire Teaching Hospitals NHS Foundation Trust (2013) where the claimant,
a 37-year-old man, received £25,000 PSLA for a medical failure to diagnose his wrist
fracture in October 2005. The claimant suffered pain and stiffness in his wrist for four years until the fracture was diagnosed; he underwent surgical procedures and was
only expected to make a 90% recovery in the future.

Medical Protection case study

Dr D, a GP, saw Mr C, a 35-year-old left-handed unemployed man who sustained an
injury while playing football. He was saving a shot and his right wrist had been forced into hyperextension by the ball. He had immediate pain over the wrist and attended his GP within 24 hours. He also reported some pain in the left wrist, but less so than the right.

Dr D took a full history and examined the wrist. There was noted to be tenderness over
the radial styloid. There was no documented examination of the anatomical snuff box or
evidence to suggest scaphoid examination had occurred.

Dr D felt that this was most likely a wrist sprain and prescribed analgesia. No x-ray was requested. Although Dr D felt he would likely have given worsening advice or safety
netting at this point, this was not recorded in the clinical record.

Twelve months later Mr C registered with a new GP and reported that he still had ongoing pain in his wrist. An examination raised suspicion of scaphoid injury and an x-ray was ordered. This showed a scaphoid non-union fracture. Mr C required an
operation with bone grafting and reported ongoing grip weakness. He made a claim
against Dr D.

Dr D advised Medical Protection that the scaphoid had not been examined and this was why it was not recorded in the medical record, as he did not consider this to be a typical mechanism for scaphoid injury.

The claim was settled for a low value after expert evidence conceded that the delay in diagnosis had contributed to the nonunion fracture and a subsequent need for arthroscopy. The expert also felt that appropriate examination would have likely
revealed some clinical signs to raise suspicion of fracture, given that signs were found one year later. The settlement value reflected the fact that Mr C had not reattended his GP to report ongoing pain and the fact his records showed that the injury had not impacted on his employment prospects.

This case highlights the need to consider that hyperextension with loading through
this mechanism should be considered in the same way as a FOOSH.

Conclusion

Scaphoid claims are a recurring theme in the context of a missed diagnosis at primary care review, or where primary care have seen a patient after they have been seen in secondary care and not had scaphoid imaging.

This can raise the question of where breach of duty ultimately lies but it reinforces the
importance of consideration of scaphoid fracture in the context of suspected wrist injuries.

References

1. Freeland P, Scaphoid tubercle tenderness: a better indicator of scaphoid fractures? Arch Emerg Med 6(1):46–50 (1989)
2. Waizegger et al, Clinical Signs in Scaphoid fracture, Journal of Hand Surgery 19B: 6: 743-747 (1994)
3. https://emedicine.medscape.com/article/328658-overview