Have you ever been working a shift at 3 AM and wondered, “Am I missing something? I’ll just splint and instruct the patient to follow up with their PCP in 1 week.” This is a reasonable approach, especially if you’re concerned there could be a fracture. But we can do better. Enter the “Can’t Miss” series: a series organized by body part that will help identify common and catastrophic injuries. This list is not meant to be a comprehensive review of each body part, but rather to highlight and improve your sensitivity for these potentially catastrophic injuries. Last post, we reviewed the elbow. Now, the “Can’t Miss” adult wrist injuries.
25% of all sports related injuries involve the hand or wrist .
Approximately 1.5% of all emergency department visits involve the hand and forearm .
Missed wrist injuries can be highly morbid if injuries are missed.
Missed wrist injuries are a common area of litigation.
Epidemiology: Accounts for 70% of all carpal fractures. This fracture has a high risk of avascular necrosis and is highly morbid.
Mechanism: Typically caused by a “fall on outstretched hand” or FOOSH.
Physical Exam: Anatomical snuffbox pain with palpation, pain at scaphoid tubercle, pain with axial loading of the thumb (Figure 1).
Pearl: It is easier to palpate the snuffbox if the patient performs ulnar deviation at the wrist.
Diagnostic Imaging: X-rays are not sufficiently sensitive to rule out scaphoid fracture. May consider scaphoid or navicular views if high index of suspicion.
Treatment: Thumb spica and follow-up with hand surgeon in 1 week for positive finding. Thumb spica and follow up for repeat exam/films in 10-14 days if the x-rays are negative but the patient has tenderness at the anatomical snuffbox.
Epidemiology: Most commonly missed ligamentous injury of wrist. High risk of scapholunate advanced collapse (SLAC) wrist leading to arthritis.
Mechanism: This injury typically occurs after FOOSH or wrist hyperextension.
Symptoms: Patient will report dorsal or radial side pain and swelling; the pain is often worse when the patient is in a “push up” position. Patient may describe a “click” at the wrist.
Physical Exam: Expect pain just distal to Lister’s Tubercle or at the anatomical snuffbox (Figure 2). Pain is worse with an extended and loaded position (a push-up position).
“Watson’s Test” or scaphoid shift test: Palpate the scaphoid tuberosity on the palmar aspect of the affected wrist while moving wrist from ulnar to radial deviation. A positive test is a painful “click” or “pop” .
Diagnostic Imaging: PA x-ray: < 2 mm scapholunate ligament space is normal (Figure 3). If a high index of suspicion for dissociation exists, obtain bilateral “clenched fist” views.
Treatment: If a high index of suspicion for dissociation exists, place the patient in a thumb spica or “Cock up” wrist splint even if films are negative [4, 5].
Figure 2: Picture taken from Tintanelli’s demonstrating anatomy of the wrist. “SL” corresponds to the scapholunate area just distal to Lister’s tubercle .
Figure 3: AP of wrist demonstrating scapholunate space widening suggesting scapholunate dissociation. Case courtesy of Radswiki, Radiopaedia.org.
Epidemiology: This is a commonly missed injury. Missed diagnoses lead to chronic instability .
Symptoms: Patients can sometimes have unremarkable or subtle exams. They may have tenderness to palpation or swelling on the volar aspect of the wrist.
Diagnostic Imaging: Disruption of Gilula’s arcs on AP. The lunate may appear as a “piece of the pie (Figure 4). These injuries are most pronounced on lateral films.
Figure 4: AP of wrist showing “Piece of Pie”. Note disruption of Gilula’s Lines. Case courtesy of Dr Andrew Dixon, Radiopaedia.org.
Perilunate dislocation: The lunate is in line with radius but the capitate appears dislocated.
Lunate dislocation: Capitate and radius are in line, the lunate is not (Figures 5, 6).
Treatment: Check for sensation and function of the median nerve.
Reduce with longitudinal traction and wrist extension.
Apply pressure on the volar aspect of the wrist in dorsal direction with flexion.
Place in sugar tong and arrange for 1-2 day follow-up if reduction is successful.
If reduction fails, orthopedics should be consulted emergently .
Figure 5: Pictorial representation of a lunate and perilunate dislocation.
Figure 6: A) normal lateral view. B) lateral view demonstrating lunate dislocation. C) lateral view demonstrating perilunate dislocation. Cases courtesy of Dr Jeremy Jones, Radiopaedia.org, Dr Andrew Dixon, Radiopaedia.org, and Dr Andrew Dixon, Radiopaedia.org. Annotations by Stephen Villa
Epidemiology: This injury often occurs with other injuries, is rarely isolated, and is missed 50% of the time on initial presentation .
Physical Exam: Pain at DRUJ joint, weak grip, restricted range of motion with pronation, ulnar head often prominent or totally absent because of swelling .
Grind Test: Compress and rotate the DRUJ. A positive test is pain or crepitus with compression maneuver .
Diagnostic Imaging: Widening of joint on PA >2 mm suggestive of dislocation. Lateral will show dorsal/volar dislocation of the ulna (Figure 11).
Treatment: Reduction: Supination reduces a dorsal dislocation, pronation reduces a volar dislocation. Once reduced, place in a sugar tong. Reduction may require sedation .
Pearl: This injury can be isolated but usually associated with distal ulna fractures, TFCC tears, “Essex-Lopresti” injuries or Galeazzi injuries. Did you check that elbow?
Figure 11: A) AP Wrist of volarly dislocation at distal radioulnar joint. B) Lateral depicting dislocation. Case courtesy of Dr Craig Hacking, Radiopaedia.org. C) AP wrist of dorsal dislocation at DRUJ. D) Lateral depicting dislocation. Case courtesy of Dr Bruno Di Muzio, Radiopaedia.org.
Epidemiology: Less than 1% of all hand injuries. Associated with hamate fractures or base of metacarpal fractures.
Mechanism: Usually after fall, punching, or other high energy trauma.
Examination: Typically grossly swollen at affected area.
Diagnostic Imaging: AP x-ray will show loss of clear joint space between carpals and metacarpals. Lateral x-ray typically shows clear dislocation if the dislocation involves the 4th or 5th digit .
Treatment: Apply longitudinal traction and direct pressure on the metacarpal base, followed by placement in an ulnar gutter if the 4th or 5th digit are involved. A dorsal slab splint is preferred otherwise.
Figure 12: AP and Lateral of a 5th carpometacarpal dislocation. Case courtesy of A.Prof Frank Gaillard, Radiopaedia.org.