What is Scaphoid Wrist Fracture?
Scaphoid fractures, breaks in one of the wrist bones, are most common among young, active people and make up 2% to 7% of all fractures. In fact, they constitute 60% to 70% of wrist bone fractures. Because of their similarity to less severe injuries, these fractures are often initially overlooked or mistaken for a simple wrist sprain during both clinical check-ups and x-ray examinations.
Incorrectly diagnosing this fracture can lead to serious health problems for the patient, as, if unaddressed, the bone may not heal properly—in up to half of the cases when the bone is displaced. Furthermore, untreated fractures of this type can result in arthritis, deformity, and instability within five years, leading to a significant loss of function. This situation can have a substantial impact, particularly as these injuries usually occur in young, active people. The subsequent health issues and necessary treatments can lead to considerable costs.
What Causes Scaphoid Wrist Fracture?
People usually experience wrist pain after falling on an outstretched hand. This is because the scaphoid bone, a small bone in the wrist, can hit the edge of the radius bone in your forearm when your wrist is forced to stretch extremely and lean towards the thumb side. This impact can cause a fracture. Activities like contact sports and car accidents are also frequent causes of such injuries. Diseases like tumors or infections that weaken the bone are rare themselves, but they can occasionally cause scaphoid fractures.
Risk Factors and Frequency for Scaphoid Wrist Fracture
Scaphoid fractures mostly impact young adults, with the average age being 29. These fractures are more common in males. It’s uncommon to see these fractures in children and older adults because they are more prone to different types of fractures. Scaphoid fractures represent 15% of sudden injuries to the wrist.
Signs and Symptoms of Scaphoid Wrist Fracture
A scaphoid fracture usually results in pain and swelling at the base of the thumb, in a region known as the anatomic snuffbox. This condition often follows a recent traumatic incident, leading to wrist pain. These fractures can be missed in basic X-Rays, potentially leading to late diagnosis. The pain is usually focused on the radial side of the wrist (the thumb side) and tends to amplify with movement. Incorporating with the pain, patients could also experience swelling and limited wrist movement. Smokers should take special note that they have around a 20% higher risk of non-healing of the fracture.
A health professional examining a wrist for a possible scaphoid fracture would typically use a method called “look, feel, move.” A visible deformity isn’t a common sign unless there’s also a dislocation in the wrist bones. The health professional would touch and feel the ends of radius and ulna (the two long bones of the forearm) and the base of the fingers to check for potential associated injuries. There’s classically tenderness in the anatomic snuffbox area on the back of the wrist, particularly with fractures. This area is bounded by certain tendons, with the tendons of the muscles abductor pollicis longus and extensor pollicis brevis on the thumb side, and the tendon of extensor pollicis longus on the side facing the little finger. Tenderness can also be felt near the scaphoid tubercle, a bony prominence on the radial side of the wrist found near the flexor carpi radialis tendon at the level of the base of the palm. Fracture-related tenderness usually shows up in one of these three locations:
- On the palmar side at the wrist’s distal end for fractures of the scaphoid’s distal pole
- In the anatomic snuffbox for fractures at the waist or middle segment of the scaphoid
- Distal to Lister’s tubercle, a bony bump on the back of the distal end of the radius, for fractures of the scaphoid’s proximal pole
Besides these, the scaphoid compression test is another way to identify a scaphoid fracture. It involves compressing the scaphoid bone between an examiner’s index finger and thumb. The presence of a fracture often results in pain with this action. Lastly, experiencing pain in the anatomic snuffbox when moving the wrist towards the little finger side can also suggest a scaphoid fracture.
Testing for Scaphoid Wrist Fracture
If a person is suspected of having a fracture in their wrist bone, several kinds of x-rays are taken first. These x-rays include the front and side views of the wrist, along with some special views focusing on the wrist bone called the scaphoid. These special views require the person’s wrist to be held at certain angles during the x-ray.
However, x-rays might not show up to 25% of these fractures right away. If the doctor strongly believes there could be a fracture, they might recommend keeping the wrist stable with a splint or cast for about a week to two weeks. They would then repeat the x-rays. If an earlier confirmation of a fracture is needed, a bone scan could be done three days after the injury.
If the repeat x-rays are still not clear, and the doctor still suspects a fracture, an MRI or CT scan might be done. An MRI can give the most accurate diagnosis in these cases. It can also show any injury to the ligaments or bruising of the bone. Experts believe MRIs for this use are almost 100% accurate.
A CT scan can also be used. It’s pretty accurate too, but it might miss a fracture if the bone pieces are not displaced by more than 1 mm.
If surgery is needed, regular blood tests would be done. These tests would look at the full blood count, electrolytes, clotting ability, and blood type.
Treatment Options for Scaphoid Wrist Fracture
If a bone break is minor and un-shifted, and it’s in the lower part of the bone, it can generally be treated without surgery by immobilizing the area with a cast. Medical professionals are still debating whether it’s best to use a full arm cast or a half arm cast, and whether or not the thumb should be immobilized too with a thumb spica. However, no scientific evidence currently supports one option over the other.
Likewise, the duration of wearing a cast depends on the location of the fracture. For instance, a break in the lower third of the bone would typically heal in 6-8 weeks. A break located in the middle third could take 8-12 weeks, and a break toward the top could require anything from 12- 24 weeks. This healing timeline is directly related to the degree of blood supply in these areas.
There are certain conditions where surgery might be necessary. These include if the bone has moved more than 1mm from its original position, if the angle inside the scaphoid bone is more than 35 degrees, if the angle of the radius and lunate (a bone in the wrist) has increased to over 15 degrees, or if the bone is shattered into many pieces. Surgical treatment may also be needed for certain types of fractures such as a fracture at the narrowest part of the scaphoid, even if there is no noticeable shifting of the bone, especially for individuals who need to quickly return to work or sports activities. The same applies to instances where the bone does not heal as expected, or when blood supply to the bone is severely interrupted.
The surgical procedure involves the insertion of screws or wires, either through small incisions or through a larger cut. This decision depends largely on the condition of the fractures. If the bone fragments are not knitting well or if they are significantly shifted from their original positions, surgeons usually opt for the more traditional open surgery method.
Correct positioning of the screw in the central part of the bone is essential for the most stability, quicker healing, and the best overall alignment. Depending on the exact location of the fracture and the preference of the surgeon, access to the area for the procedure can be from the palm side (volar approach) or the back side (dorsal approach) of the wrist.
If the broken bone fails to heal, there are several different treatment options. In the early stages, surgeons can potentially reposition the bone and secure it internally with a bone graft. This graft usually comes from the lower arm bone near the wrist or from the hip bone. If there is already evidence of arthritis in the wrist joint, additional procedures might be considered. These include removing the top part of the broken bone, fusing the areas of the wrist bones together, removing the radial styloid (a bone in the wrist), or removing the proximal row of wrist bones entirely. These are considered as last resort procedures to restore functionality to the joint.
What else can Scaphoid Wrist Fracture be?
If you’re experiencing wrist pain, it might be due to a variety of conditions. These could include:
- Fracture of the distal radius, which is a break in the larger of the two bones in your forearm, near your wrist.
- Fractures in other bones in the wrist, also known as the carpal bones.
- Scapholunate dissociation, a condition where the ligament between two of the small carpal bones in the wrist gets injured or torn.
- De Quervain tenosynovitis, where the tendons around the base of your thumb are swollen, causing pain on the thumb side of your wrist.
- Osteoarthritis, a condition that causes your joints to become painful and stiff. It can occur in any joint but is often in hands and wrists.
- Tendonitis, which is inflammation or irritation of a tendon, often triggered by a strain or overuse.
It’s important for a healthcare professional to determine the exact cause of your symptoms in order to give you the right treatment.
What to expect with Scaphoid Wrist Fracture
If you have a scaphoid fracture (a broken bone in your wrist) where the bone pieces are less than 1mm apart, there’s a 90% chance the bone will heal completely. However, this healing rate might decrease if the fracture has been moved too far apart, has not been correctly diagnosed, or if the fracture is at the top part of the bone.
If this type of fracture doesn’t get the treatment it needs, there’s an increased chance you could deal with chronic pain. This pain could potentially also come with a decreased range of motion and grip strength in hand.
Possible Complications When Diagnosed with Scaphoid Wrist Fracture
The scaphoid is a small bone in the wrist. Missing a break or fracture in the scaphoid can lead to complications – one of the most common ones being nonunion, where the bone does not heal properly. This usually happens when the bone is really out of alignment or if there are additional fractures in the wrist bones. Surgery is usually needed to fix this.
There are three stages of nonunion:
- Radioscaphoid arthritis, which affects the bone’s joint with the radius (the larger of the two bones in the forearm).
- Scaphocapitate arthritis, which affects the joint with the capitate bone (one of the small bones in the middle of the wrist).
- Lunocapitate arthritis, which occurs when the lunate bone (one of the eight small bones in the wrist) and the capitate bone are affected.
The final stage is known as the Scaphoid Nonunion Advanced Collapse (SNAC). This is usually treated with surgery to fuse the wrist or remove the row of bones in the wrist that are causing the problem.
Another common issue with a missed scaphoid fracture is avascular necrosis, which happens when the bone doesn’t get enough blood and starts to die. About 30-40% of people with a missed scaphoid break will experience this, and it’s most likely to occur in the proximal pole, the top part of the scaphoid bone closest to the forearm.
Other complications can include scapholunate dissociation, where one of the main ligaments in the wrist is injured, and delayed union, where the bone takes longer than usual to heal.
Recovery from Scaphoid Wrist Fracture
Physiotherapy plays a crucial role in the care of patients with fractures, whether they’ve had surgery or not. It aids in restoring their wrist’s range of motion and strength. In the early phases, when swelling is most prevalent, it’s essential to keep the hand raised. At this time, movements of the fingers, elbow, and shoulder should be encouraged to prevent stiffness.
After the wrist is immobilized – either for fractures managed without surgery or post-surgery – it tends to stiffen. Physiotherapy is critical to safely increase mobility. Exercises to improve the active range of motion and rotation of the wrist should begin once the cast is removed.
After surgery, the wrist is initially immobilized with a ‘back-slab’ below the elbow. Two weeks later, it’s replaced with a full cast after checking the wound and taking repeat X-rays. The patient typically remains in the full cast for six weeks post-surgery. At this point, another set of X-rays is taken. If these show that the bone is healing, the cast can be removed. A wrist brace may then be worn for another six weeks to protect the wrist.
Usually, patients can safely return to driving and playing sports after about 3 months.
Preventing Scaphoid Wrist Fracture
If you’re someone who engages in activities where there’s a high chance of falling on an outstretched hand, using a removable wrist splint can be very helpful. Not only does this protect your wrist, but it can also be removed at your discretion. Additionally, if you’re a smoker, it’s strongly recommended that you quit. This is because smoking can slow down the process of fracture healing. This advice is applicable to everyone– whether you’ve undergone a surgery for your fracture or are managing it without an operation.
