Four questions for Dr. Tamara Rozental, Professor of Orthopaedic Surgery at Harvard Medical School

Linked Orthopaedia chapter: https://www.orthopaedia.com/scaphoid-fractures/

Dr. Tamara Rozental,  Professor of Orthopaedic Surgery at Harvard Medical School, answers four questions on scaphoid  fractures, among other things. [Related information can be found in the Orthopaedia chapter on scaphoid fractures.]

Orthopaedia: Scaphoid fractures can be troubling. Even when a timely diagnosis is made, the fracture does not always heal right.  But maybe there is hope on the horizon. I am thinking about fabricating a custom scaphoid replacement with 3-D printing. If that works,  when a fracture fails to heal, surgeons like you can just pop in prosthesis, much like is done with a radial head fracture.  Might that work?

TAMARA D. ROZENTAL: There have been attempts to replace the scaphoid with a prosthesis but these have been limited by problems with biomechanical stability, material wear and the development of arthritis in the surrounding bones.

One issue is that replacing the scaphoid is not enough. We would also have to replace the scapholunate ligament, which is attached to the proximal pole of the scaphoid.  An intact scapholunate ligament is important in maintaining normal wrist dynamics.  Without the scapholunate ligament, the other bones in the wrist become unstable, leading to cartilage wear and eventually arthritis.

In cases where scaphoid fracture was missed and the proximal portion of the scaphoid has progressed to osteonecrosis, we have typically resorted to salvage procedures which include removing the entire proximal row of the carpus or excising the scaphoid and fusing the remaining carpal bones.  More recently, surgical advances have focused on harvesting vascularized bone graft from the knee to replace the necrotic portion of the bone.  Although the early results from this are encouraging, inserting a vascularized bone graft requires major surgery and is never simply “popped in.”

Orthopaedia: You have convinced me–scaphoid fractures are not going to be easy! But if so, are there any reasonable preventative steps people can follow in high-risk activities to avoid scaphoid fractures? Do wrist guards, for example, help?

TAMARA D. ROZENTAL: There are many sporting, high-risk activities that can lead to scaphoid fractures.  Obviously, being familiar with the techniques and surroundings can help decrease the risk of injury.  Avoiding falls on outstretched wrists is probably the most important factor in avoiding scaphoid injuries.  There is evidence that wearing wrist guards for activities such as snowboarding, for instance, can decrease the rate of the wrist injury (sprains, ligament injuries and fractures) by a 50%.

To date, there has been little research examining the use of wrist guards specifically for the prevention of scaphoid fractures.  Snowboarding remains the only sport where the use of wrist guards has been proven to be efficacious. Nonetheless, the American Academy of Pediatrics recommends the use of protective gear for skateboarding and skating, and I agree.

Orthopaedia: So, if we can’t prevent all scaphoid fractures, at least we should not miss the diagnosis once it appears. Yet that can be tricky. As noted on the American Academy of Orthopaedic Surgeons patient information website, “In some cases, a scaphoid fracture does not show up on an X-ray right away.” The AAOS goes on to say, “If your doctor suspects you have a fracture but it is not visible on X-ray, they may recommend that you wear a wrist splint or cast for 2 to 3 weeks and then return for a follow-up X-ray.”  Do you follow that protocol? And if not, why not?

TAMARA D. ROZENTAL: My approach to these injuries is largely based on my level of clinical suspicion.  Most patients with an acute scaphoid fracture will have tenderness, swelling, bruising and some limitation in the wrist range of motion.  In these cases, rather than placing patients in a cast and repeating x-rays in 10, I prefer to obtain advanced imaging.  This can be in the form of a CT scan or an MRI. 

I typically prefer an MRI as it will reveal any other bone or ligamentous injuries.  If the MRI is negative, I feel confident that I can tell patients to resume normal activities and that the pain will gradually subside.

Of course, MRI is expensive and is not always immediately available. In these cases, you have to weigh the cost of time away from work and activities during a period of casting with the cost of the MRI which provides an immediate definitive answer. I suspect that over the years to come, obtaining a CT or MRI in the emergency room will become more common.

Orthopaedia: The question about addressing the possible scaphoid fracture that an x-ray misses –the so-called “occult fracture” –assumes that the patient has made it to the x-ray machine. But the all too common occurrence of finding an old, previously-unknown fracture in a patient with hand pain suggests that at least some scaphoid fractures are not recognized at the time they are sustained–perhaps misattributed to a sprain or the like. What pearls can you could share with primary care practitioners to make sure the diagnosis is not missed?

TAMARA D. ROZENTAL: It is important to maintain a high level of clinical suspicion in these cases.  If patients’ present with a high energy mechanism of injury that could be consistent with a fracture and also have pain, swelling or limited range of motion, it is always safer to treat them as if they had sustained a scaphoid fracture even if you don’t see the fracture definitively.

It is rare for patients with normal, painless range of motion to have sustained a scaphoid injury. In addition to pain in the anatomic snuffbox (the small the depression on the back of the hand at the base of the thumb between the tendons). Patients with scaphoid injuries commonly have pain when an examiner presses on the base of the thumb on the palm side as well–this puts pressure of the proximal pole of the scaphoid.

If a patient presents to a primary care office with a history and clinical exam concerning for fracture, I suggest obtaining an x-ray and placing them in a thumb spica splint until further consultation and/or imaging can be obtained. Imaging can establish the diagnosis and rule out other more significant injuries (such as a perilunate dislocation).

If the initial x-rays are negative, my preference is to obtain definitive imaging in the form of a CT scan or an MRI as soon as possible to rule out the presence of a fracture.  If the level of suspicion is lower, I think it is reasonable to immobilize patients’ for 7 to 10 days and perform another clinical examination with repeat radiographs at that stage.