Chapter 1 – Hand and wrist emergencies



Chapter 1 Hand and wrist emergencies




Carl A. Germann



Distal radius and ulnar injuries




PEARL: Fractures of the distal radius and ulna are the most common type of fractures in patients younger than 75 years.




PEARL: Distal radius and ulnar injuries are often associated with median and ulnar neuropathies.



Distal radius fracture



Key facts





  • A Colles fracture (Figures 1.1 and 1.2): A transverse fracture of the distal radial metaphysis with dorsal displacement and angulation, often caused by a fall on an outstretched hand



  • A reverse Colles or Smith fracture (Figure 1.3): A transverse fracture of the metaphysis of the distal radius, with associated volar displacement and volar angulation. The mechanism of injury is often a fall on to the dorsum of the hand with the wrist in flexion



  • Barton fracture (Figure 1.4): A distal radius fracture with dislocation of the radiocarpal joint




    • A volar Barton fracture occurs when the wrist is volarly flexed, and affects the volar rim of the radius.



    • A dorsal Barton fracture occurs with dorsal flexion and affects the dorsal rim of the radius




  • Hutchinson fracture (Figure 1.5): An intra-articular transverse fracture of the radial metaphysis with extension through the radial styloid, often caused by a direct blow or a fall on the radial side of the wrist




    • Also termed a Chauffer’s fracture




  • Clinical presentation: distal radius fracture patterns usually present with pain, swelling, and deformity of the wrist



  • On physical examination, Colles fractures have a dinner-fork deformity caused by the dorsal displacement and angulation of the radius



  • Smith fractures often have fullness on the volar aspect of the wrist



  • Median nerve injury can occur with Colles and Smith fractures and a careful neurovascular examination both on initial presentation and following treatment is required





Figure 1.1 Colles fracture. Note the dorsal angulation of the distal radius as shown in Figure 1.2.


(Image courtesy of Carl Germann, MD.)

Figure 1.2




Figure 1.3 Smith fracture. The hand and wrist is volarly displaced with respect to the forearm.


(Image courtesy of Carl Germann, MD.)




Figure 1.4 Volar Barton fracture. A fracture of the volar margin of the carpal surface of the radius.


(Image courtesy of Carl Germann, MD.)




Figure 1.5 Hutchinson fracture: An intra-articular fracture through the radial styloid process.


(Image courtesy of Carl Germann, MD.)



Diagnostic testing





  • For Colles and Smith fracture patterns, radiographs of the wrist will demonstrate the fracture through the radial metaphysis. The lateral radiograph is the best view to determine the degree of dorsal or volar displacement and angulation



  • The lateral radiograph is the best view for revealing an intra-articular fracture of the radius and any associated carpal displacement in Barton fractures. A posteroanterior (PA) radiograph often shows a comminuted fracture of the distal radius



  • PA radiographs of the wrist are best to see a Hutchinson fracture




Treatment





  • Colles fractures should undergo closed reduction. This can be facilitated by the use of a hematoma block and finger traps. After successful reduction, patients should be immobilized in a long-arm splint in neutral position or pronation with orthopedic follow-up in 7 to 10 days. Emergent orthopedic consultation is necessary if initial attempts at closed reduction are unsuccessful, if there is neurovascular compromise, or if there is an open fracture



  • Smith fracture should undergo closed reduction. Following reduction, patients should be placed in a long-arm splint in supination. Emergent orthopedic/hand-specialist consultation is recommended for these fractures because they are more likely to be unstable and urgent surgical management is more often necessary



  • Barton fractures require emergency orthopedic/hand-specialist consultation for early operative management



  • Non-displaced Hutchinson fractures can be managed with a short-arm splint and routine orthopedic/hand-specialist follow-up. Displaced fractures require reduction and immobilization. Accurate anatomic alignment following reduction is essential because multiple ligaments of the wrist attach to the radial styloid process and inappropriate alignment can cause future complications




Prognosis





  • Complications include:




    • Malunion



    • Radioulnar and radiocarpal instability



    • Arthritis



    • Chronic pain



    • Non-union




  • However, good to excellent results are often achieved in most patients




Distal radioulnar joint disruption (DRUJ)



Key facts





  • Disruption of the distal radioulnar joint (DRUJ) may be seen as an isolated injury, or more commonly, in association with distal radius fractures




    • Initially unrecognized in up to 50% of cases




  • Dorsal dislocations are the most common and are typically the result of a fall on to an outstretched arm with a rotational pronation force to the impact



  • Volar dislocations are typically the result of a fall on to an outstretched arm with a rotational supination force to the impact




Clinical presentation





  • Often overshadowed by more apparent injuries



  • On physical examination a dorsal dislocation reveals excessive prominence of the ulnar head and lack of forearm rotation secondary to pain when the wrist is supinated



  • Volar dislocations will have a loss of the typical dorsal prominence of the ulnar head and lack of forearm rotation secondary to pain when the wrist is pronated




Diagnostic testing





  • PEARL: In DRUJ injuries, the lateral radiograph usually demonstrates volar or dorsal displacement of the ulna that normally overlap the radius. Standard radiographs of a DRUJ dislocation demonstrate overlap of the distal ulna with the distal radius on the PA view. On the lateral view the ulnar head will be displaced:




    • Dorsally for dorsal dislocations



    • Volarly with volar dislocations




  • Radiographic signs of DRUJ instability are:




    • Ulnar styloid fracture involving the base with more than 2 mm displacement



    • Irreducible dislocation of the DRUJ



    • Fractures involving the sigmoid notch of the radius



    • Wide displacement of the DRUJ



    • Radial shortening





Treatment





  • If DRUJ instability is suspected, based on clinical examination or radiographic studies, an emergent orthopedic or hand-specialist consultation should be obtained for reduction and immobilization




Prognosis





  • DRUJ injuries have a high recurrence rate and may require reconstructive surgery




Carpal bone fractures and dislocations



Scaphoid fracture




PEARL: The scaphoid is the most commonly fractured carpal bone yet one of the most commonly missed wrist injuries. A thorough history and physical examination, coupled with a high index of suspicion, are necessary to make the diagnosis.




Key facts





  • Scaphoid fractures account for 60–70% of all diagnosed carpal injuries



  • Radiographic findings (Figure 1.6) can be subtle or absent, rendering the diagnosis difficult to make



  • Accurate early diagnosis of scaphoid fractures is critical, as a missed or delayed diagnosis can result in long-term pain, loss of mobility, and decreased function



  • The scaphoid has a high rate of non-union



  • Avascular necrosis of the scaphoid is because its blood supply arises distally from small branches of the radial artery and the palmar and superficial arteries. The proximal portion of the scaphoid is completely dependent on this distal blood supply, thus it is at risk of avascular necrosis following fracture



  • In general, the more proximal, oblique, or displaced the fracture, the greater the risk of interrupting the blood supply





Figure 1.6 Scaphoid fracture: An acute non-displaced fracture is shown in anteroposterior view.


(Image courtesy of Carl Germann, MD.)



Clinical presentation





  • Snuff box tenderness is classically cited as the most common finding, although the sensitivity of this test is disputed



  • Many authors feel a better test for scaphoid injury is axial compression of the thumb along its longitudinal axis



  • The examining physician (EP) should remain vigilant for associated injuries that can be found on physical examination




    • Common associated injuries include fractures of the distal radius, lunate, or radial head at the elbow



    • Median nerve injury has also been described in association with scaphoid fractures





Diagnostic testing




PEARL: Even with appropriate films, fractures of the scaphoid can be subtle and difficult to visualize. Conservative estimates suggest that 10–20% of these fractures will not be visible on any view in the acute setting.




  • A typical wrist series includes a PA and lateral radiograph of the wrist



  • In cases where there is high clinical suspicion, a scaphoid view of the wrist can also be obtained




    • This reduces the foreshortening of the scaphoid that occurs on a normal PA view, and displays the entire length of the scaphoid



    • However, even with excellent radiographic technique, a fracture may not be visualized




  • Magnetic resonance imaging (MRI) and computed tomography (CT) have much better sensitivity and specificity in detecting scaphoid fractures. However, these are not routinely done in the ED as it does not affect the initial treatment, which consists of immobilization and orthopedic follow-up for clinically suspected scaphoid injury




Treatment





  • Reduce swelling in the extremity (i.e., elevate, apply ice)



  • Provide adequate pain control



  • Remove any restrictive clothing, splints, casts, jewelry, etc



  • Confirmed or suspected scaphoid fractures with normal radiographs require a thumb spica splint




PEARL: Confirmed or suspected scaphoid fractures require that the patient be placed in a thumb spica splint.



Prognosis





  • The most common complication of scaphoid fractures is non-union, which has an overall occurrence rate of 8%–10%



  • The rate of non-union varies with the actual fracture site




    • Non-union complicates up to 20%–30% of proximal- third fractures, and 10% –20% of middle-third fractures



    • Non-union of distal-third fractures is relatively rare




  • Besides non-union, patients are also at risk to develop avascular necrosis (AVN) of the scaphoid, which occurs in approximately 10% of proximal pole fractures, and 5% of middle-third fractures




Lunate fracture



Key facts





  • Lunate fractures account for 3.9% of all carpal bone fractures



  • Isolated lunate fractures are uncommon except in the case of Kienböck’s disease, also known as idiopathic avascular necrosis of the lunate



  • Associated injuries of the radius, carpal bones, or metacarpals occur 50% of the time




Clinical presentation





  • The typical mechanism of injury for a lunate fracture is a fall on to an outstretched hand



  • Patients with lunate fractures will present with pain over the dorsum of the wrist that is exacerbated by palpation of the dorsal aspect of the lunate



  • Axial loading of the third metacarpal can also accentuate the pain




Diagnostic testing





  • Standard wrist radiographs often fail to demonstrate lunate fractures because visualization of the lunate is often obscured by superimposed bones



  • CT has been found to be more sensitive than plain radiography at identifying fractures of the lunate




Treatment





  • Early identification and management of these fractures is essential to prevent AVN, carpal instability, and non-union



  • Patients with suspected or diagnosed lunate fractures should be immobilized in a thumb spica splint with the hand and thumb in neutral position



  • Lunate fractures require a hand-specialist follow-up in 1 to 2 weeks




Prognosis





  • Lunate fractures are at risk of avascular necrosis leading to:




    • Osteoarthritis



    • Chronic pain



    • Decreased grip strength





Triquetral fracture



Key facts





  • Third most common carpal bone fracture following scaphoid and lunate fractures



  • A fall can lead to impingement of the hamate or ulnar styloid process on to the triquetrum




Clinical presentation





  • Patients often present following a direct blow to the wrist or a fall on to an outstretched hand



  • Localized tenderness should be present over the dorsum of the wrist distal to the ulnar styloid




Diagnostic testing





  • Lateral wrist radiographs may show a dorsal chip fracture of the triquetrum



  • A pronated lateral view often projects the dorsal triquetrum away from other carpal bones



  • Triquetral body fractures are best visualized on anteroposterior (Figure 1.7) and oblique radiographs





Figure 1.7 Triquetral fracture: Anteroposterior radiograph of a subtle triquetral fracture.


(Image courtesy of Timothy Sweeney, MD.)



Treatment





  • Immobilization of the wrist with a short-arm splint and prompt orthopedic follow-up is recommended



  • Displaced fractures often require internal fixation




Prognosis





  • The deep branch of the ulnar nerve lies in close proximity to the triquetrum and may cause motor impairment



  • Non-union, malunion may occur




Pisiform fracture



Key facts





  • The pisiform is rarely fractured and accounts for only 1.3% of all carpal bone fractures



  • Pisiform fractures are most often caused by a direct blow or fall on to an outstretched hand



  • Less commonly the pisiform can be avulsed by the flexor carpi ulnaris during forced wrist hyperflexion or from the strain of lifting a heavy object




Clinical presentation





  • Patients with fractures of the pisiform complain of ulnar-sided wrist pain that is accentuated by resisted wrist flexion



  • Physical examination demonstrates pain over the pisiform



  • Occasionally, ulnar nerve palsy may result from compression by a fragment of the pisiform which serves as the ulnar wall of the Guyon’s canal, which the ulnar nerve transverses




Diagnostic testing





  • Diagnosis of a pisiform fracture is difficult on standard radiographs because adjacent and overlying bones prevent an unobstructed view of the pisiform



  • If a pisiform fracture is suspected special views, such as a carpal tunnel view or a reverse oblique view with the wrist in 30° of supination, can be helpful in imaging the pisiform



  • CT can be used if clinical suspicion of pisiform fracture persists despite normal or non-diagnostic plain radiographs




Treatment





  • Immobilize in an ulnar gutter splint for 3 to 4 weeks



  • If ulnar nerve palsy is present, hand-specialist consultation should be obtained for possible surgical decompression




Prognosis





  • Most ulnar nerve palsies that are present at initial presentation will resolve in 8 to 12 weeks and require only close observation



  • Pisiform fractures have an excellent prognosis




Carpal bone dislocations



Key facts





  • Perilunate and lunate dislocations result from hyperextension



  • Perilunate dislocations are more common, and lunate dislocations are more severe



  • Perilunate and lunate dislocations generally are the result of high-energy trauma to the wrist, with the most common mechanism being a fall on to the outstretched hand, followed by motor vehicle and motorcycle crashes



  • Carpal bone dislocations are a progressive pattern of carpal ligamentous injuries caused by wrist hyperextension and ulnar deviation



  • Mayfield’s study of the pathomechanics of these injuries led to the classification of carpal bone dislocations into four distinct stages with each stage representing a sequential intercarpal injury beginning with scapholunate joint disruption and proceeding around the lunate, creating progressive ligamentous injury and progressive carpal bone instability




PEARL: The intracarpal distance between the scaphoid and lunate should not be more than 2 mm.




  • Stage I injury (scapholunate dissociation):




    • Results in a characteristic widening of the scapholunate joint on the PA view – Terry Thomas sign (Figure 1.8)



    • A gap of 2 mm or less between the scaphoid and lunate is considered normal on the PA view



    • Scapholunate dissociation can be associated with a rotatory subluxation of the scaphoid, where the scaphoid is seen on end with the cortex of the distal pole appearing as a ring shadow superimposed over the scaphoid; this is known as the “signet ring sign



    • Standard radiographs are usually normal, so when a scapholunate ligament injury is suspected clinically, additional stress views can be obtained



    • Views taken in ulnar deviation with a clenched fist (the clenched fist AP view) will accentuate widening of the scapholunate joint




  • Stage II injury (perilunate dislocation):




    • Seen best on the lateral view of the wrist (Figure 1.9)



    • Although the lunate remains in normal position in relation to the distal radius, the capitate is dislocated, usually in a dorsal direction



    • The PA view often will show overlap of the distal and proximal carpal rows and may also demonstrate an associated scaphoid fracture or subluxation (Figure 1.10)




  • Stage III injury:




    • Appears similar to a stage II injury but with the addition of a dislocation of the triquetrum, best seen on the PA view, with overlap of the triquetrum on the lunate



    • The stage III injury is frequently associated with a volar fracture of the triquetral bone




  • Stage IV injury (lunate dislocation):




    • Results in a characteristic triangular appearance of the lunate on the PA view, also known as the “piece of pie” sign (Figure 1.11)



    • This is caused by the rotation of the lunate in a volar direction



    • The triangular appearance of the lunate when dislocated is in stark contrast to its normal quadrangular appearance (Figure 1.12)



    • This rotation is also visible on the lateral view of the wrist, where the lunate looks like a tea cup tipped in a volar direction that has spilled its contents (“spilled teacup sign”) into the palm (Figure 1.13)



    • On the lateral view, the capitate will lie posterior to the lunate and can even migrate proximally and make contact with the distal radius.




PEARL: In a lunate dislocation, the lunate will appear as a “spilled teacup” on the lateral wrist radiograph.





Figure 1.8 Scapholunate dislocation: Terry Thomas sign.


(Image courtesy of Timothy Sweeney, MD.)




Figure 1.9 Perilunate dislocation: Dorsal displacement of the capitate is identified on the lateral view.


(Image courtesy of Timothy Sweeney, MD.)




Figure 1.10 Perilunate dislocation: Posteroanterior radiograph showing overlap of the distal and proximal carpal rows. This is often referred to as a “jumbled carpus.”


(Image courtesy of Timothy Sweeney, MD.)




Figure 1.11 Lunate dislocation: Rotation of the lunate resulting in a triangular appearance on posteroanterior view.


(Image courtesy of Carl Germann, MD.)




Figure 1.12 Lunate dislocation: Normal quadrangular appearance of the lunate.


(Image courtesy of Carl Germann, MD.)




Figure 1.13 Lunate dislocation: Volar displacement of the lunate (“spilled teacup sign”).


(Image courtesy of Carl Germann, MD.)


Clinical presentation





  • Carpal bone dislocation injuries typically are the result of a high-energy mechanism such as fall from a height on to the outstretched hand, or a motor vehicle crash



  • The mechanism of injury is ulnar deviation of the wrist coupled with dorsiflexion



  • The patient will complain of pain and swelling over either the dorsum or volar aspect of the wrist and have limited range of motion



  • On physical examination there will likely be palpable tenderness over the dorsum of the wrist, particularly in the region of the scapholunate ligament, located just distal to Lister’s tubercle



  • With palpation alone it is often difficult to distinguish one source of wrist pain from other causes, including scapholunate strain, scaphoid fracture, triangular fibrocartilage complex tears, and other disorders




Diagnostic testing





  • Plain radiographs of the wrist consisting of PA and lateral views are essential to diagnose wrist dislocations (as well as other carpal bone instabilities)



  • The PA view should be obtained with the wrist in a neutral position



  • A relatively constant 2 mm intercarpal joint space should be seen on a normal PA view. An increase in this distance suggests ligamentous interruption, or a stage I injury (scapholunate dissociation)



  • On the AP view, three arcs should be identified (Figure 1.14)




    • The first arc consists of the radiocarpal row, which should be both smooth and continuous. Disruption of this arc is suggestive of a lunate dislocation



    • The second arc consists of the mid-carpal row, which should similarly be smooth and continuous. Disruption of this arc is suggestive of a perilunate dislocation



    • The third arc outlines the proximal surface of the distal carpal row. Disruption of any of these arcs is a sign of carpal dislocation or fracture




  • On the lateral view the radius, lunate, and capitate should all line up in a row (Figure 1.15)




    • The lunate should lie within the radius cup and the capitate should rest within the lunate cup



    • Loss of this normal column configuration implies lunate or perilunate dislocation



    • Stress x-rays obtained with radial and ulnar deviation of the hand may demonstrate scapholunate dissociation






Figure 1.14 Normal AP arcs: Disruption suggests carpal dislocation or fracture.


(Image courtesy of Carl Germann, MD.)




Figure 1.15 Normal lateral arcs: Disruption suggests lunate or perilunate dislocation.


(Image courtesy of Carl Germann, MD.)



Treatment





  • Reduce swelling in the extremity (i.e., elevate, apply ice)



  • Provide adequate pain control



  • Remove any restrictive clothing, splints, casts, jewelry, etc



  • Carpal bone dislocations usually mandate the consultation of a hand surgeon in the ED for reduction and stabilization



  • Open fractures and open dislocations require temporary splinting, IV antibiotics and prompt operative intervention (keep NPO)



  • Closed reduction and long-arm splint immobilization may be attempted but is frequently unsuccessful. If attempted, it is more likely to be successful with a perilunate rather than lunate dislocation because of the extent of ligamentous disruption in the latter



  • If the dislocation is irreducible or the result is unstable, then open reduction with internal fixation is required



  • Many authors believe immediate open reduction with internal fixation is the treatment of choice, citing the extensive ligamentous injury inherent in such injuries, and frequent unstable results that come with closed reduction



  • A lunate or perilunate injury with median nerve symptoms requires immediate operative reduction, carpal tunnel release, and ligamentous reconstruction




Prognosis





  • Complications of carpal dislocation include median nerve injury resulting in an acute or subacute carpal tunnel syndrome



  • Other complications include chronic carpal bone instability with resultant degenerative arthritis, chronic pain, and limitation in range of motion



  • Scapholunate advanced collapsed deformity (“SLAC wrist”) is the end-stage result for many patients


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Jan 19, 2021 | Posted by in EMERGENCY MEDICINE | Comments Off on Chapter 1 – Hand and wrist emergencies
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