The scaphoid is one of the eight bones that make up the wrist, and the most frequently fractured. The mechanism responsible is often a fall landing on the hand, leading to extreme movement of the wrist in flexion or extension. The most common symptoms are pain, sometimes associated with swelling. They are not very specific, however, and may be identical to those of a wrist sprain.
A scaphoid fracture may not heal if not properly treated, which is why it’s important to take care in making the right diagnosis. The rate of healing of scaphoid fractures depends on the location of the fracture: it is easier in the distal region (located closer to the end of the wrist), which is better supplied with blood, than in the proximal region (closest to the radius), where blood supply is less abundant.
What tests are needed for scaphoid fractures?
The doctor’s examination of the wrist helps guide the investigation.
In addition to assessing the scaphoid, they can also be used to rule out other wrist lesions. Sometimes the fracture is not immediately visible on X-rays. Consequently, it may be necessary to repeat the examination two to three weeks later, as the fracture may become visible at this time.
MRI (magnetic resonance imaging)
In some cases, particularly if pain persists in the scaphoid region and X-rays do not show a fracture, an MRI scan may be useful to clarify the diagnosis.
CT scan (X-ray imaging)
In other cases, a CT scan is indicated, depending on the type and location of the fracture.
What are the treatments for this fracture?
When a scaphoid fracture or suspected fracture is present, plaster cast immobilization is recommended as a precautionary measure. Its aim is to rest the wrist, which is the classic treatment for sprains. Immobilization usually lasts two to three weeks, until a second series of X-rays (or MRI in some cases) can be taken to confirm or rule out the fracture. If there is no fracture, the cast is removed and a removable splint worn to relieve any residual pain. If there is a fracture and it is not displaced, immobilization in a cast for between six and twelve weeks is the standard treatment.
Surgery is generally proposed for scaphoid fractures that are displaced or have a poor healing prognosis (proximal region). The procedure involves stabilizing the bone with a fully embedded screw that can remain permanently in place. The operation is performed under local anaesthetic. A cast is applied after surgery. As the arm is still asleep, it is not possible to drive home.
After a few days, the plaster cast is replaced by a removable splint, enabling progressive mobilization to be initiated as pain levels increase. It is quickly abandoned, except in certain specific cases. X-rays are taken regularly to ensure good progress.
The same procedure can also be proposed for simpler, non-displaced fractures, to shorten the duration of cast immobilization (one to two weeks instead of two or three months).
Physiotherapy and occupational therapy are often prescribed after the cast has been removed.
Time off work depends on the profession, but can last up to three or even four months. It is sometimes shorter when surgery is performed. In principle, the practice of sports requiring the use of the operated hand is forbidden until complete healing of the fracture has been confirmed by X-ray or CT scan.
What are the possible complications?
Common to all surgeries
Infection of the wound may occur, but is usually cured by local care and the prescription of antibiotics. Surgical drainage is rare.
Hematoma corresponds to an accumulation of blood under the skin. It’s not a problem if it’s small, but if it’s larger, surgical evacuation may be necessary.
Healing problems (delayed healing, thick scars) occur more frequently in patients who smoke.
Inadvertent injury to an artery, nerve, ligament or tendon is always possible, although rare. These structures can be repaired, but recovery may be prolonged or even incomplete.
Chronic regional pain syndrome is a disproportionate inflammatory reaction of the body following surgery. It causes pain, swelling and stiffness, requiring treatment that can last several months.
Complications specific to scaphoid fracture
The fracture may take longer than expected to heal(delayed healing, between three and six months) or never heal at all(pseudarthrosis, after six months). In the event of non-union, surgery is generally required to prevent the onset of osteoarthritis.
The risk of developing early cartilage wear, i.e. osteoarthritis, can occur after a few years, although this is rare if the fracture has consolidated.