Wrist Injuries: Pearls and Pitfalls

Author: Justin Bright, MD (Senior Staff EM Physician, Henry Ford Hospital) // Editor: Alex Koyfman, MD

Wrist pain is a frequent emergency department complaint. Most presentations are due to an acute traumatic injury. Furthermore, overuse or repetitive motion mechanisms cause ED visits for either an acute injury or an exacerbation of chronic pain conditions. For the purposes of this post, the wrist is going to be defined as injuries occurring to the distal radius and ulna, as well as any injury to the carpal bones. In addition, I feel it to be a poor use of this forum to simply list every conceivable form of wrist injury. Instead, I’d like to discuss the following:

—Pertinent questions you need to ask your patient when evaluating a wrist injury
–Pain management techniques including hematoma blocks
–Which fractures have a higher likelihood of developing avascular necrosis
—What type of splint is indicated for a particular injury

PAIN CONTROL
The first pearl in dealing with wrist injuries – treat the patient’s pain early! In severe injuries, the patient may be experiencing too much pain to give a detailed story regarding mechanism of injury. Over 70% of wrist injuries can be correctly identified based on understanding mechanism alone. I find it better to treat the patient’s pain and then circle back to ask more detailed questions regarding injury. In addition, there are times when the injury is too painful to allow for a full complement of radiographic images. This could lead to missed injuries.

You have a number of options in your tool box when deciding how best to treat pain. First and foremost, get in the habit of making sure an ice pack is given to the patient promptly. I have gotten into the habit of walking into the room with an ice pack when I first see the patient just in case they don’t have one. It helps with pain control, may reduce swelling to facilitate a better exam later on in your encounter, and gives the patient a better overall experience. Use of systemic pain medication is at the discretion of the provider, and your choice of medication will be based upon severity of the injury and pain response, as well as other co-morbid conditions. In general, PO or IM pain control is more than adequate.

If you are faced with an injury requiring closed reduction, such as a radial-ulnar fracture, you should absolutely utilize a localized hematoma block. Infiltration with an anesthetic (usually lidocaine or bupivicaine) and judicious use of systemic pain medication is usually more than adequate to provide the patient with enough comfort to reduce the fracture without need of procedural sedation. Most reductions of wrist fractures can be done quickly, and the time, resources, and potential added risk to the patient make procedural sedation a far less attractive option. There is a fantastic description of how to do a wrist hematoma block at:

http://www.epmonthly.com/features/current-features/hematoma-blocks-for-reduction-of-distal-radius-fractures-/

PERTINENT QUESTIONS
There are a number of important questions to ask your patient when evaluating a wrist injury. The most relevant question is, “How did this happen?” Having the patient describe the mechanism of injury will allow you to understand the bone(s) most likely injured. Most common are falls on outstretched hands (FOOSH) injuries. A patient that falls forward is more likely to have an excessive force on the radial aspect of the wrist, leading to distal radius injuries and injuries involving the scaphoid bone. Falls backwards cause the arm to be supinated with excessive ulnar force, causing injury to the distal ulna, the ulnar stylus, triquetrum, and lunate. Most FOOSH injuries affect the patient’s dominant arm because it’s the one they reflexively use to brace against their fall.

It is also imperative to ask your patient what their occupation is, what their dominant hand is, and what recreational activities they participate in. For overuse injuries in particular, these questions will often provide important information regarding location of pain, as well as what types of movements cause the pain. Also, in my own career I have found it very helpful to ask women if they have been lifting or carrying infants or young children. Countless times I have found that their pain is reproduced when asked to demonstrate how they carry the child. It is extremely important to do a thorough neurosensory exam of the wrist and hand. Fractures with neurologic deficit carry with it a much higher morbidity, and as a result a much greater likelihood of lost wages and productivity due to disability. If there are neurologic symptoms associated with the injury, you must either get orthopedic consultation in the ED or insure prompt outpatient follow-up. You should not just give your patient the orthopedist’s office number and tell them to call for an appointment. These injuries should involve a direct discussion with orthopedics and you need to lock down an actual time for follow-up.

CAN’T-MISS INJURIES
When examining a patient with a forward FOOSH injury, your primary concern when evaluating the wrist has to be for scaphoid injuries. Scaphoid injuries are the most common carpal bone fracture, representing 70% of all carpal bone fracture. The scaphoid bone is highly susceptible to avascular necrosis if injury isn’t identified and the wrist properly splinted because the blood supply to the bone is disrupted. It can be difficult to identify on standard radiography, and sequelae of missed injury can lead to long-term disability as well as litigation.

The most common physical exam finding in a scaphoid injury is tenderness over the anatomic snuffbox. It has a sensitivity greater than 90%, but a specificity below 40%. Thus, false negatives are very possible on exam. I find it helpful to also evaluate for pain at the scaphoid with axial loading of the thumb (pushing thumb towards wrist). In addition, many orthopedic texts recommend evaluating for pain while pronating and ulnar deviating the wrist. What further complicates scaphoid injuries is the delayed presentation of fractures on standard wrist radiographs. It is quite common for no fracture lines to appear on radiographs during the initial presentation, only to have a fracture be evident on subsequent radiographs or MRI on orthopedic follow-up. The general rule must be, if you have even the slightest suspicion of a scaphoid injury, place the patient in a thumb spica splint and refer for orthopedic follow-up.

Posterior FOOSH injuries can cause ligamentous instability of carpal bones, and if not properly managed, can also cause avascular necrosis. Most notable are perilunate and lunate injuries. This injury occurs more frequently when the patient falls backwards onto an outstretched hand. Sometimes the force of the injury is enough to also fracture the scaphoid bone, further complicating management. In addition, perilunate and lunate injuries are ripe for visual stimuli on board exams because of their classic radiographic findings. A perilunate dislocation occurs when the lunate bone stays in relatively normal position, but the capitate bone is dorsally displaced. Conversely, in a lunate dislocation, the lunate bone angulates dorsally, while the remaining carpal bones remain in their normal alignment. The lunate dislocations have the classic “spilled tea cup” appearance. Another popular radiographic finding is the “Terry Thomas sign” of a scapholunate dissociation (Terry Thomas was an actor with a big gap between his front teeth.)

“spilled teacup” of lunate dislocation

Scapholunate dissociation

Terry Thomas

IMMOBILIZATION TECHNIQUES
So now that you’ve identified a wrist injury, do you splint it or cast it? Should you use plaster or orthoglass? How should you apply it? My personal practice for wrist pain due to repetitive use or wrist sprain is to apply a Velcro wrist splint that offers volar support. I find that it stabilizes the wrist, offering comfort due to the immobilization at the wrist, while also allowing full movement of the fingers. It can be easily removed and reapplied by the patient, making things like sleeping and daily hygiene easy.

It is important to understand the difference between splinting with orthoglass and casting with plaster. The benefit of orthoglass splinting is that it’s non-circumferential, which allows room for swelling. It is faster and less messy than plaster casting, which is an important consideration for a provider in a busy emergency department. Overall, there are less complications associated with splinting, but skin breakdown can still occur if not careful in the manner in which the knit stocking, cotton/synthetic webril, and orthoglass itself are applied. Orthoglass splints are removable, which again benefits the patient when taking care of daily hygiene and sleeping. Conversely, because it is easy to remove and reapply, the overall compliance rates are lower.

I can say in my more than 7 years as a physician that I have never applied a plaster cast. My general feeling is, if casting is indicated, then so is an emergency department orthopedic consultation. Casting is circumferential, and if removed, cannot be reapplied. Circumferential casting is far less forgiving to acute phase swelling. As a result, compartment syndrome is a much higher risk with plaster casting relative to orthoglass. Skin breakdown is also more likely. It needs to be said however, that plaster casting does offer superior immobilization and greater likelihood of patient compliance.

Location Type Indication Pearls Follow-up

Wrist injuries will be something you encounter frequently in your patients. It is important to understand the mechanism, dominant hand, occupation, and other activities that may contribute to the injury so you can best immobilize your patients and ensure appropriate follow-up. Maintain a healthy respect for potential scaphoid injuries and have an incredibly low threshold to place suspected injuries in a splint. Understand the indications and different techniques in orthoglass splinting. Splinting is quick, provides comfort to your patient, and if you’re the one who applies/supervises it, drives up your RVUs! Be liberal with your pain control of acute injuries, and don’t hesitate to use hematoma blocks in appropriate patients. Finally, have a firm understanding of who needs orthopedic consultation immediately, and who can be seen in a few days in an outpatient setting.

References/Further Reading

1. Loeser JD, Bonica JD. Bonica’s Management of Pain, 3rd ed, Lippincott Williams & Wilkins, Philadelphia 2001.
2. Halikis MN, Taleisnik J. Soft-tissue injuries of the wrist. Clin Sports Med 1996; 15:235.
3. Seitz WH, Papandrea RF. Fractures and dislocations of the wrist. In: Rockwood and Green’s Fractures in Adults, Bucholz RW, Heckman JD (Eds), Lippincott Williams & Wilkins, Philadelphia 2002. p.749.
4. Dobyns JH, Beckerbaugh RD, Bryan RS, et al. Fractures of the hand and wrist. In: Hand Surgery, 3rd, Flynn JE (Ed), Williams & Wilkins, Philadelphia 1982.
5. Eiff MP, Hatch RL, Calbach WL. Carpal fractures. In: Fracture Management for Primary Care, 2nd, Saunders, Philadelphia 2003.
6. Emergency Physicians Monthly, Online Edition, September 7, 2012. http://www.epmonthly.com/features/current-features/hematoma-blocks-for-reduction-of-distal-radius-fractures-/
7. Anne S. Boyd, MD, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania. Holly J. Benjamin, MD, University of Chicago, Chicago, Illinois. Chad Asplund, MD, The Ohio State University College of Medicine, Columbus, Ohio. Am Fam Physician. 2009 Sep 1;80(5):491-499.
8. Stanbury SJ, Elfar JC. Perilunate dislocation and perilunate fracture-dislocation. J Am Acad Orthop Surg 2011; 19:554.
9. Budoff JE. Treatment of acute lunate and perilunate dislocations. J Hand Surg Am 2008; 33:1424.
10. http://www.ncbi.nlm.nih.gov/pubmed/21871237
11. http://www.ncbi.nlm.nih.gov/pubmed/17384376
12. http://www.ncbi.nlm.nih.gov/pubmed/24630805
13. http://www.ncbi.nlm.nih.gov/pubmed/24977995
14. http://www.ncbi.nlm.nih.gov/pubmed/24673666
15. http://www.ncbi.nlm.nih.gov/pubmed/24113485
16. http://www.ncbi.nlm.nih.gov/pubmed/23588975