Scaphoid Fracture

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Epidemiology

Most commonly in men aged 15-25.

  • Waist area: 60-85%
  • Distal third: 25%
  • Proximal third: 5-15%

Clinical Assessment

Scaphoid fracture usually results from fall onto an outstretched hand generally during a sports-related event. The patient describes radial-sided pain but there may be relatively little pain.

Accuracy of Clinical Tests in Diagnosing Scaphoid Fractures.[1]
Test and Study Quality Description and Positive Findings Population Reference Standard Sens Spec + LR - LR
Snuffbox tenderness[2] Examiner palpates anatomic snuffbox. Positive if pain is elicited 85 patients presenting to emergency department with mechanism of injury suggesting possible scaphoid fracture Radiographic confirmation of scaphoid fracture 100% 98% 50.0 0.0
Pain with resisted supination[2] Examiner holds patient’s hand in handshake position and directs patient to resist supination of forearm. Positive if pain is elicited 100% 98% 50.0 0.0
Pain with longitudinal compression of thumb[2] Examiner holds patient’s thumb and applies long-axis compression through metacarpal bone into scaphoid. Positive if pain is elicited 98% 98% 49.0 0.02
Anatomic snuffbox tenderness[3] Examiner palpates anatomic snuffbox. Positive if pain is elicited 221 patients with a suspected scaphoid injury 100% 29% 1.41 0.0
Scaphoid tubercle tenderness[3] Examiner applies pressure to scaphoid tubercle. Positive if pain is elicited 83% 51% 1.69 0.33
Scaphoid compression tenderness[3] Examiner holds patient’s thumb and applies long axis compression through metacarpal bone into scaphoid. Positive if pain is elicited 100% 80% 5.0 0.0

Imaging

Plain Radiographs

For plain radiographs, a scaphoid series should be done. This includes four projections of the scaphoid bone and is positionally different from the wrist series. Initial radiographs can miss 5-20% of fractures in the acute setting.

Features include:[4]

  • visualisation of the fracture +/- displacement
  • soft tissue swelling and lateral displacement of the adjacent fat pads
    • scaphoid fat pad sign: obliteration or lateral displacement of a straight/convex lucent line on the lateral aspect of the scaphoid 11
  • associated scapholunate ligament disruption (Terry Thomas sign) which can be accentuated with a clenched fist view

The first sign of avascular necrosis is slight sclerosis.

See radiopaedia for radiology cases.[4]

MRI

The international standard for the initial assessment appears to be early MRI in the presence of clinical features and a normal radiograph, or CT if MRI is not available. In New Zealand neither of these imaging modalities is available in primary care. MRI is preferred due to to its superior sensitivity and sensitivity, and also as it can pick up other injuries.

In some areas there may be rapid access to a specialist clinic. Otherwise the patient should be offered a private MRI.

Treatment

The lack of availability of MRI or CT in primary care in New Zealand has implication on management. If the patient is not able to access early MRI, the standard practice is treat any FOOSH injury with scaphoid tenderness in spite of a normal radiograph as a possible fracture, and immobilise in POP for 10 days.

If there is no MRI available then review in 10-14 days and organise a follow up x-ray.

The initial immobilisation method of a diagnosed fracture is either a split scaphoid cast or a backslab. There should be slight palmar flexion and radial deviation. Do not include the thumb

lab. Have slight palmar flexion and radial deviation - the thumb is not included.

Further management depends on the type of fracture:

  • Mid-waist or distal fracture: Below elbow cast without the thumb. At one week change to fibreglass if POP was used initially. At 6 weeks remove the cast and x-ray. If the patient is still uncomfortable then request a CT to assess healing.
  • Scaphoid tubercle fracture: Below elbow cast for 4-5 weeks for comfort. Non-urgent orthopaedic assessment is recommended.
  • Proximal scaphoid fracture: Consider surgery if displacement of 1mm or more

If there is a partial scapholunate ligament injury or extrinsic dorsal ligamentous injury then treat with a compression bandage and refer for physiotherapy for splinting and rehabilitation.

If there is complete scapholunate ligament rupture (scapholunate dissociation) then refer to orthopaedics for consideration of surgery. In this condition there is a gap between the scaphoid and lunate of ≥ 3 mm. A clenched fist view can be used to confirm.

Hand physiotherapy should be offered following scaphoid injuries.

Prognosis

Incorrect management can lead to delayed union, non-union, or avascular necrosis. Delayed union or non-union is usually due to delayed or inadequate stabilisation, but can also be due to fracture instability.

Further Reading

  • Clementson et al 2020[5].

References

  1. Cleland, Joshua, Shane Koppenhaver, and Frank H. Netter. Netter's orthopaedic clinical examination : an evidence-based approach. Philadelphia, Pa: Saunders/Elsevier, 2011.
  2. 2.0 2.1 2.2 Waeckerle JF. A prospective study identifying the sensitivity of radiographic findings and the efficacy of clinical findings in carpal navicular fractures. Ann Emerg Med. 1987;16:733-737
  3. 3.0 3.1 3.2 Grover R. Clinical assessment of scaphoid injuries and the detection of fractures. J Hand Surg [Br]. 1996;21:341-343
  4. 4.0 4.1 https://radiopaedia.org/articles/scaphoid-fracture
  5. Clementson et al.. Acute scaphoid fractures: guidelines for diagnosis and treatment. EFORT open reviews 2020. 5:96-103. PMID: 32175096. DOI. Full Text.