You are in: eMedicine Specialties > Plastic Surgery > HAND Hand, Fractures and Dislocations: WristArticle Last Updated: Jul 6, 2006AUTHOR AND EDITOR INFORMATIONSection 1 of 12
  Author: Abdulaziz T A Jarman, MD, BS, FRCS(C), Fellow, Division of Cosmetic Plastic Surgery, Department of Surgery, University of Alberta Coauthor(s): Ali Ghahary, BSc, MD, Department of Surgery, Division of Plastic and Reconstructive Surgery, University of Alberta; Edward E Tredget, MD, MSc, FRCSC, Professor, Department of Surgery, University of Alberta, Director, Firefighters Burn Treatment Unit, University of Alberta Hospital, Director, Plastic Surgery Wound Healing Reserach Laboratory, University of Alberta Editors: Milton B Armstrong, MD, FACS, Associate Professor of Clinical Surgery, Associate Professor of Clinical Orthopedics, Department of Surgery, University of Miami Miller School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; David W Chang, MD, FACS, Associate Professor, Department of Plastic Surgery, MD Anderson Cancer Center, The University of Texas; Nicolas (Nick) G Slenkovich, MD, Practice Director, Colorado Plastic Surgery Center at Swedish Medical Center; Jorge I de la Torre, MD, FACS, Professor of Surgery and Physical Medicine and Rehabilitation, Residency Program Director, Division of Plastic Surgery, University of Alabama at Birmingham; Director, Center for Advanced Surgical Aesthetics Author and Editor Disclosure Synonyms and related keywords: fractured wrist, broken wrist, dislocated wrist, scaphoid fracture, dorsal intercalated segment instability, DISI, scaphoid waist fractures, avascular necrosis, AVN, lunate fracture, scaphoid dislocation, lunate dislocation, Kienbock disease, Kienbock's disease, transcarpal injury, perilunate dislocation, fracture dislocation, perilunate fracture dislocation, carpal fracture, transscaphoid disruption, trans-scaphoid disruption, transcapitate disruption, trans-capitate disruption, transtriquetral disruption, trans-triquetral disruption, axial dislocation, axial fracture dislocation, axial-radial-ulnar dislocation, axial-radial dislocation, triquetral fractures, pisiform fractures, hamate fractures, scaphocapitate syndrome INTRODUCTIONSection 2 of 12
  This review covers primary fractures and dislocations involving the wrist region. The wrist is composed of the region between the forearm and the hand. Its complex movements are essential to human functioning. A dissemination of knowledge with regard to wrist and carpal injuries has occurred since the 1960s. Significant improvements in imaging, treatment, and physician training have been achieved in the last 2 decades, yet injuries remain frustrating to treat for doctors and patients. For excellent patient education resources, visit eMedicine's Breaks, Fractures, and Dislocations Center. Also, see eMedicine's patient education articles, Wrist Injury and Broken Hand. FrequencyIn the United States in 1998, an estimated 1,465,874 hand and forearm fractures were observed. This accounted for 1.5% of all emergency department visits. Radius and ulna fractures are the most common (44%). Approximately 18% of all hand fractures are carpal fractures. Scaphoid fractures are by far the most common of the carpal fractures, estimated at 79%. Triquetrum fractures make up 14% of all carpal fractures. Trapezium fractures make up 2.3% and hamate fractures make up 1.5%, while lunate, pisiform, and capitate fractures combine for 3%. Trapezoid fractures are rare, encompassing 0.2% of all carpal fractures. Injuries occur more commonly in young, active, and energetic males and are also common in osteoporotic elderly persons. EtiologyMost wrist fractures and dislocations are a result of axial loading on the outstretched palm and extended wrist, usually from a fall, motor vehicle accident, or sport contact injury. Most result in fractures of distal radius, scaphoid, and other carpal fractures. Higher-impact injuries from falls or severe motor vehicle accidents can lead to more complex perilunate fractures and dislocations of the carpus or wrist. PathophysiologyExtensive research has been conducted on elucidating the pathology of wrist injuries and building classification schemes to help study and develop treatment modalities. This is best described by dividing wrist injuries as follows: Scaphoid FractureFracture of the scaphoid has been explained as a failure of bone caused by a compressive tension load, by torsion, or by rotation forces. During a fall, higher levels of dorsiflexion (95°-100°) and radial deviation (10°) during impact can result in scaphoid fractures. The most common site of fracture is the waist region of the scaphoid (65%). These are less stable but much more rare. Of all fractures of the scaphoid, including those associated with intercarpal ligament injuries, 65% occur at the waist, 15% at the proximal pole, 10% through the distal body, 8% through the volar tuberosity, and 2% through the distal articular surface. Several classification systems have been proposed for scaphoid fractures. Russe described scaphoid fractures on the basis of orientation, including horizontal oblique, vertical oblique, and transverse fractures. The vertical oblique fracture is considered to be the least stable and most likely to require surgical intervention. Other classification systems, proposed by Cooney et al, state that scaphoid fractures can be classified as displaced and nondisplaced. Scaphoid fractures are best described by Herbert, where fractures are categorized into an alphanumeric system.
Displacement or instability is defined as displacement of the fragment by at least 1 mm angulation, shown by a radiolunate angle of more than 15°or a scapholunate angle of more than 60°. Understanding that the carpal configuration is in carpal rows is useful (see Relevant Anatomy). The carpus can be thought of as a 3-bar linkage system, with the radius, proximal row (ie, lunate, triquetrum), and distal row (ie, hamate, capitate, trapezoid, trapezium) aligned in a linear fashion (see Image 2). The scaphoid acts like a bridge between the proximal and distal rows and provides carpal stability. Under compressive forces, the scaphoid flexes. The counterbalance to this is the natural extension of the triquetrum. Both bones try to influence the lunate through their respective ligamentous attachments, but in opposite directions (see Image 3). Once scaphoid integrity is lost, an imbalance occurs and the lunate extends and assumes a dorsal tilt. Through the scapholunate ligament complex, the proximal pole of the fractured scaphoid also assumes an extended (dorsal) position. However, the distal fragment of the scaphoid is still loaded by the overlying trapezium and trapezoid, which causes the fragment to flex in a volar humpback direction. With the loss of colinearity, the entire carpus becomes unstable and subject to collapse. The lunate and proximal rows lie dorsal, thus the term dorsal intercalated segment instability (DISI). These forces result in a large gap at the fracture site and a high incidence of delayed union, nonunion, and malunion. Because the blood supply of the scaphoid is mostly interosseous and oriented in a distal to proximal direction, fractures of the scaphoid waist and proximal pole can interrupt this tenuous supply and predispose the proximal pole to avascular necrosis (AVN). Fractures of the middle third are associated with a 30% incidence of AVN, fractures of the proximal pole are associated with a nearly 100% incidence of AVN, and the healing time of the more proximal scaphoid fractures is prolonged because of the pole vascularity of the proximal part of the scaphoid. Lunate FractureLunate fracture accounts for approximately 1% of all carpal fractures (excluding Kienbock). Lunate fractures also occur with axial loads to the dorsiflexed wrist. However, lunate fractures are correlated more with ulnar deviation of the wrist during impact. Lunate fractures are rare compared to scaphoid fractures. They are difficult to treat and perhaps even more difficult to diagnose. Lunate fractures invariably precede Kienböck disease, which occurs when the lunate undergoes AVN. This eventually leads to collapse of the carpus and pancarpal arthritis. Five types of lunate fractures have been described, based on location and vascular supply.
Type 1 fractures result from hyperextension and compression from the capitate and radius; the radiolunate and lunotriquetral ligaments pull in radial and ulnar directions, respectively. The distal palmar pole is avulsed by the lunotriquetral ligament. Type 2 fractures result from Kienböck disease but may also result from shearing related to lunate dislocation or subluxation. Type 3 fractures result from shear force as the capitate dislocates dorsally in perilunate dislocation or from avulsion of the scapholunate ligament in acute rotatory subluxation of the scaphoid. Type 4 fractures result from shear forces induced from a radial carpal fracture dislocation. Type 5 fractures result from hyperextension as the short radial lunate ligament avulses the palmar pole while capitate forces the lunate into extension. This also happens in palmar perilunate dislocation as a shear force. Kienböck DiseaseIn 1910, Kienböck described lunate collapse as the result of progressive vascular compromise resulting from repetitive wrist sprains and contusions. They are now understood to be characteristic lesions from failure of the lunate fractures to unite (often the dorsal pole). The incidence and progression of Kienböck disease relies on a combination of risk factors. These include ulnar (minus) variance, lunate geometry, lunate vascular pattern, triangular fibrocartilage complex compliance, intraosseous pressure gradients, vocational loads, and underlying congenital and developmental disorders. All factors are pathophysiologically important, each to varying degrees. However, describing and understanding the concept of ulnar variance is the most clinically relevant. Ulnar variance refers to the distance between the articular surfaces of the radius and ulna. Ulnar-minus means the ulna is relatively short with respect to the radius and the articulating surface and vice versa. Inequality in the length of the forearm bones leads to differential stress loading of the lunate, leading to disease. During impact on a dorsiflexed and ulnarly deviated wrist, a short ulna contributes to the stress forces across the lunate and contributes to fracture, thus explaining the correlation with ulnar-minus variance and the incidence of Kienböck disease. This concept forms the basis of various surgical procedures designed to unload the lunate by transferring the load to more lateral carpal columns. Kienböck disease is best described in 4 stages based on progression of the disease clinically and radiologically.
TriquetrumThe triquetrum fracture is the second most common fracture, after the scaphoid. Triquetrum fractures have two main types.
The mechanism of chip fractures has been debated. Some think the mechanism is due to avulsion of the conjoined insertion of the dorsal intercarpal or dorsal radiocarpal ligaments with hyperextension and radial deviation, while some think it is due to direct impact from the ulnar styloid or hamate with hyperextension. TrapeziumThe trapezium fracture is the third most common carpal fracture. Five types of trapezium fractures exist.
TrapezoidThe trapezoid fracture is rare. CT scan or MRI may be needed to diagnose a trapezoid fracture. Two types of trapezoid fractures exist.
These fractures are rare and are usually associated with fracture dislocation that involves dislocation of the index metacarpal or the trapezoid itself. Force is usually axial along the index metacarpal bone. CapitateThe capitate fracture is second to the trapezoid fracture in rarity. The proximal pole is entirely intra-articular, without soft tissue attachment. Capitate fractures can be categorized into 4 types.
Types 1 and 2 occur with extreme dorsiflexion. The transverse body fracture occurs in isolation but occurs more commonly with scaphoid fractures in what is known as scaphocapitate fracture syndrome. Other types of capitate fractures occur as result of hyperextension, axially loading injuries, or both. HamateHamate fractures are most common in stick- or bracket-handling sports (eg, golf, baseball, tennis). The vascular supply is most tenuous at the waist of the hamate hook. Two types of hamate fractures exist.
Hook fractures have several causes. Fractures can result from a direct blow or from repetitive contusions. Indirect avulsions through forceful pull of the flexor carpi ulnaris (FCU) and avulsion through the pisiform hamate ligament can cause hook fractures, as can a crush injury. Body fractures can result from severe wrist fracture dislocation, direct blow to the ulnar hand, anteroposterior crush injury, or transcarpal carpal metacarpal dislocations, resulting in dorsal coronal fracture with posterior subluxation of the fourth and fifth metacarpal bones. PisiformOften regarded as proximal carpal bone, it is truly a sesamoid bone within the FCU. Pisiform fractures fall into 4 categories.
The most common mechanism is fall or impaction directly to the pisiform with wrist extended. Active firing of the FCU results in transverse fractures; also ADM contraction can cause ulnar border avulsion. Perilunate Dislocation and Fracture DislocationSeven percent of carpal injuries fall into this category. Cooney et al classified carpal dislocations to 5 categories.
These transcarpal injuries result from more extreme hyperextension injuries of the wrist such as violent motor vehicle accidents or high-impact falls. The position of the wrist and magnitude and direction of the fall or impact determine the fracture/dislocation pattern. Fracture dislocations are twice as common as pure ligamentous dislocations, yet both are relatively uncommon. The pathophysiology focuses on zones of vulnerability where most carpal fractures and dislocations occur. The potential lines for cleavage around the lunate can be divided into a lesser arc and a greater arc (see Image 4). The lesser arc is the ligamentous zone surrounding the lunate bone, and injury to this zone results in perilunate dislocation. The greater arc consists of the bony structures surrounding the lunate, including the scaphoid, trapezium, capitate, hamate, and triquetrum. Combined fracture and ligament disruption to this zone results in perilunate fracture dislocation. Perilunate dislocations Lesser-arc injury is best understood within the context of progressive perilunate instability. This concept describes a predictable sequence of ligamentous injury leading to perilunate and lunate dislocation as described by Mayfield et al.
Perilunate (stage III) and lunate dislocations (stage IV) display different dislocation patterns and alignments, yet they are understood to be manifestations of the same progressive disease. Perilunate fracture dislocations Greater-arc injuries are characterized by complete loss of contact between the lunate and head of the capitate and one or more fractures of bones surrounding the lunate. Several potential patterns for disruption are possible. In either case, disruption occurs through the greater arc, while the dorsal intercarpal ligaments remain intact; thus, the distal carpal row is displaced dorsally and proximally over the proximal row. The fracture may begin at the radial styloid and extend through the scapholunate interosseous ligament through to the lunotriquetral joint. Alternatively, the fracture can begin at the scaphoid waist and tear through ligaments until the capitate, hamate, triquetrum, and distal scaphoid are carried away from the lunate and proximal scaphoid. Finally, the fracture can begin at the scaphoid waist and continue interosseously, fracturing the capitate and tearing through to the triquetrum. In all cases, the triquetrum can fracture directly or tear at the lunotriquetral ligament. Simply, the carpal fractures can be classified into 3 stages.
Axial Dislocation and Fracture DislocationThis describes global disruption of the carpus into longitudinal patterns parallel to the long axis of the limb. Injuries occur in industrial accidents in which machinery applies high-energy force combined with dorsal and palmar compression to the hand. The incidence of axial carpal disruption has been estimated at 1.4-2.08% of patients with carpal fracture dislocations or subluxations. Variables include magnitude, velocity, duration, and angle point of application of force. Parallel compression results in dislocation, whereas pressure under more oblique angles also results in fractures. In addition to universal tearing of the flexor retinaculum, important intercarpal ligament tears (eg, palmar hamate-capitate, palmar capitate-trapezium) disrupt the normal springlike integrity of the carpal arch. The wrist can split into 2 or more columns, usually with the metacarpals displacing along with the corresponding carpal bones. Garcia-Elias et al described 2 major groups of injuries in this category.
Most fractures are of the axial-ulnar type, in which injury is often at or around the hamate and capitate (see Image 5A). An ulnar column is created that is displaced proximal and ulnar. Axial-radial dislocation occurs when the ulnar carpus remains aligned but the radial carpus is displaced (see Image 5B). Usually, the trapezium is dislocated along with the first metacarpal, or a combined trapezoid-trapezium dislocation can occur with the first, second, and third metacarpals. In the axial radial dislocation, combined axial-radial-ulnar dislocation has also been reported. Isolated Carpal DislocationsIsolated carpal dislocations are extremely rare and a challenge to treat. Lunate dislocations are the most common type and occur in the context of progressive stage IV perilunate instability. Dislocation is almost always in a palmar direction. The rare dorsal dislocation occurs during wrist flexion injury. Scaphoid dislocation occurs with forceful dorsiflexion while an object is grasped and the wrist is ulnarly deviated. The 2 clinical types that have been reported are isolated anterolateral dislocation of the proximal pole of the scaphoid and scaphoid dislocation associated with an axial derangement of the capitohamate joint. Triquetral dislocations occur in a palmar and dorsal direction. Palmar dislocation can contribute to carpal tunnel pressures and lead to median neuropathy. Pisiform dislocation occurs with injury directly to the ulnar carpus or hyperextension traction of the flexor carpi ulnaris that tears the pisohamate or pisometacarpal ligament. Trapezoidal dislocations occur with a dorsal blow to the second metacarpal during wrist flexion. Because of the pyramidal shape of the trapezoid and the weak dorsal ligaments, the trapezoid is dislocated in a dorsal direction. Trapezium dislocations occur in dorsal and palmar directions. They occur with crush injuries either alone or with radial-axial dislocations. The hamate can be dislocated in dorsal and palmar directions. Direct, indirect, or crush trauma associated with axial dislocations is the cause. ClinicalMost patients with wrist injuries present with a history of a fall on an outstretched palm and extended wrist. Scaphoid fracture This usually manifests as pain and swelling of the radial wrist after a traumatic event, usually a fall on the outstretched hand or a motor vehicle accident. The classic presentation is swelling in the anatomic snuffbox, although this is not specific to scaphoid fractures. Physical examination reveals limited range of motion, pain upon radial deviation and flexion, pain with pronation and ulnar deviation, pain with scaphoid compression via axial load to the first metacarpal, and diminished grip strength. Patients can present with pain and tenderness months after a traumatic event; in this situation, the pain is often a vague and aching pain in the wrist. Lunate fracture Uncomplicated lunate fractures usually manifest as simple wrist sprains or can remain painless. Upon palpation, dorsal tenderness may be observed between the Lister tubercle and third metacarpal. Most fractures are difficult to diagnose, and patients often do not present until AVN has occurred. The patient presents with chronic wrist pain and tenderness localized dorsally over the lunate. Diffuse swelling and grip weakness may be observed. Disease progression involves stiffness, clicking, crepitation, and grinding, with increasing pain. Triquetral fracture Triquetral fractures are most commonly associated with other carpal injuries and can be seen with both perilunate and axial ulnar injury. Isolated fractures are seen less frequently. They can result from a fall with the wrist in extension and ulnar deviation. Direct impaction by the ulnar styloid and a direct blow to the dorsum of the wrist are common mechanisms of injury. Trapezium fractures These fractures are usually associated with other carpal bone fractures, especially the first metacarpal and the radius. Dislocation is very rare. Symptoms include the presence of localized tenderness and swelling following the injury. Fractures of the wrist are tender immediately distal to the palpable distal tuberosity of the scaphoid. The tenderness of the body fracture of the trapezium is more easily elicited anterior or dorsal to the tendon of the abductor pollicis longus, about 1cm distal to the tip of the radial styloid. Some motion can be pain-free, but pinch strength is weak. Sometimes, fractures of the trapezial ridge can result in median nerve compression symptoms. Trapezoid fractures This type of fracture is rare, as the trapezoid is well-protected by strong ligaments with the trapezium, capitate, and index metacarpal and by the bony geometry of the carpometacarpal articulation. Trapezoid fractures are usually associated with trapezoid and index metacarpal dislocations, as in axial pattern fracture dislocation. Palmar dislocation is also possible. Capitate fractures Isolated capitate fractures are often undisplaced, but most of the fractures can be found in combination with other major carpal bones, especially the scaphoid (scaphocapitate syndrome). Diagnosis depends on a degree of suspicion, which should be present when evaluating a scaphoid fracture. Hamate fractures Fracture of the body or the hook of the hamate can present similarly. Usually, the patient experiences pain on the ulnar half of the wrist and localized swelling and tenderness over the dorsal ulnar projection of the body of the hamate. These injuries should be suspected for ulnar wrist pain in golf, tennis, baseball, and squash players. Pisiform fractures This type of fracture is very uncommon. About half of pisiform fractures occur in association with other upper extremity injuries that can delay the diagnosis of pisiform fractures. They are most commonly caused by a direct blow to the hypothenar eminence. Perilunate dislocation Patients have generally diffuse tenderness with significant loss of motion and pain. Initial mild swelling increases significantly over time. The patient can have good active wrist extension, but flexion is usually limited. Crepitation also can be present. Palpation reveals disruption of the normal bony contour. In a person with a dorsal perilunate injury, the capitate can be identified as dorsal swelling. Volar perilunate dislocation can manifest with median neuropathy. Perilunate fracture dislocation Compared to other injuries, patients present with more severe pain that is incapacitating. The wrist is swollen, and patients cannot flex their fingers. The pathognomonic feature is dorsal and palmar pain upon palpation, not isolated to a single area. Again, median nerve compression is common and requires a careful neurologic examination. Axial dislocation and fracture dislocation The manifestations of injuries can range from open laceration and denudement to closed injury. Patients have extreme pain, swelling, and tenderness in the wrist. Combined injury and dislocation of the metacarpals and phalanges is common. Serious neurovascular compromise and a variety of ligamentous and tendon disruptions can be evident upon examination. Isolated carpal fractures Isolated carpal fractures also manifest as wrist pain and tenderness. Bruising may be evident over the trapezium, scaphoid, and hamate hook in the palm. Tenderness to palpation and swelling over the ulnar wrist suggest triquetral or pisiform fracture, which is more volar with pisiform fractures and dorsal with triquetral fractures. Also, pain with forceful wrist flexion suggests triquetral fracture. Dull aching over the hypothenar eminence and ulnar nerve palsy suggest hamate fracture (see Image 6). The hamulus is usually tender. Progressive grip weakness, pain with flexion, and lateral movement of the little finger also can be present, especially with nonunion at the injury site. Isolated carpal dislocations Isolated dislocations manifest similar to the other injuries, and symptoms are localized to the area of dislocation. Palpation may reveal a bony mass. INDICATIONSSection 3 of 12
Scaphoid Type A and other stable, nondisplaced fractures can be treated using closed methods. Short arm casting is usually sufficient, with 95% union in 11 weeks. All higher-grade and other unstable fractures are treated with open reduction and internal fixation (ORIF). Generally, operative indications include a radiolunate angle greater than 15°, a scapholunate angle greater than 60°, or a greater than 1-mm displacement of the scaphoid. Proximal fractures have high rates of nonunion, and AVN and should be treated surgically (see Image 9). Lunate - Acute lunate fracture Early diagnosis of lunate fractures is an uncommon occurrence. If discovered, immobilization is usually sufficient for healing. Displaced fractures (>1 mm) and transverse fractures require open reduction and fixation for proper vascularization and healing. Kienböck disease With stage I, immobilization in a short cast for 3 months is suggested. This may provide an opportunity for the lunate to revascularize. If no improvement is observed in 3 months, radial shortening for ulnar-minus variance is recommended. This operation significantly reduces the axial load on the lunate (redistributing it to the radioscaphoid and ulnocarpal joints) and allows for spontaneous or indirect revascularization. Otherwise, neutral or the ulnar-plus variety should be directly revascularized with a vascular bundle transfer. For stage II and IIIA, treatment is similar to stage I disease. In addition to revascularization, stage II/IIIA ulnar-plus/neutral fractures may benefit from capitate shortening or radial wedge osteotomy. For stage IIIB, triscaphe (ie, scaphotrapeziotrapezoid joint) limited fusions maintain durability and functional wrist mobility. Necrotic or fragmented lunate should be excised. For stage IV, salvage procedures are necessary, either proximal row arthrodesis or total wrist fusion. Patients whose goal is simply pain relief and return to heavy manual labor benefit most from total wrist fusion. Perilunate dislocation Dorsal perilunate and palmar lunate dislocations are the most common of these injuries. They are different manifestations of the same injury, and treatment remains essentially the same. Closed reduction and casting is rarely satisfactory and not solely recommended. Initial closed reduction has the benefit of immediate restoration of anatomy and alleviating pressures on the median nerve. In this case, postreduction radiographs are essential and only perfect alignment is acceptable. A scapholunate angle greater than 60° or a scapholunate gap greater than 4 mm indicates significant residual scaphoid subluxation. Any malalignment or instability compromises the outcome and mandates ORIF. However, most surgeons prefer initial operative management. Perilunate fracture dislocation Perilunate fracture dislocation is an indication for operative intervention. Closed reduction and percutaneous fixation is still performed, but this is generally considered to have a poor outcome and is not recommended. Often, extensive soft tissue, ligamentous, or nerve damage is present and requires operative intervention. Isolated carpal fractures Triquetrum fractures heal well with simple splint immobilization for 3-6 weeks. Nonunion is extremely rare. Pisiform fractures also heal well with splinting for similar periods. Complications are rare. Regarding the hamate, any intra-articular fracture with displacement at the capitohamate, triquetrohamate, and hamatometacarpal joints greater than 1 mm requires ORIF. Otherwise, cast immobilization is adequate. Fractures at the base of the hamate hook heal well and are treated with cast immobilization, whereas fractures that are more palmar in location heal poorly. In this case, or when casting has been attempted but failed, surgical excision is recommended and provides adequate pain relief and functional outcome (see Image 6). For the trapezium and trapezoid, fractures greater than 1 mm displacement at the carpometacarpal or scaphotrapeziotrapezoidal joint require ORIF. Otherwise, thumb spica cast/splinting is adequate. With capitate fracture, undisplaced injury to the body can be treated with cast immobilization. Intra-articular fracture of the proximal pole requires ORIF. Isolated carpal dislocations For scaphoid dislocation, closed reduction or open reduction with associated ligament repair has been advocated. Both methods have been successful, although open reduction provides the opportunity to repair ligamentous damage. Kirschner wire (K-wire) fixation is usually needed in either case. Triquetral dislocations do well with closed reduction or open reduction. Excision is recommended in cases in which a palmar location of the triquetrum has caused carpal tunnel syndrome. Pisiform dislocations require only simple excision. For trapezoidal and trapezium dislocations, closed reduction with percutaneous pin placement can be attempted, and open reduction can be used if the closed procedure fails. Hamate fractures have been successfully treated with closed and open reduction techniques and with simple excision. Axial dislocation and fracture dislocation Treatment of axial dislocations requires immediate recognition and reduction to ensure proper healing. Examination for soft tissue and neurovascular injury is critical. After adequate anesthesia, intravenous antibiotics, and debridement of dead tissue, closed reduction can be attempted and pin fixation performed. Failure to reduce, poor reduction alignment, or tendinous/neurovascular injury require operative reduction and fixation. RELEVANT ANATOMYSection 4 of 12
Bone anatomy The wrist is composed of 8 bones, including the scaphoid, lunate, triquetrum, pisiform, hamate, capitate, trapezoid, and trapezium (see Image 1). The largest bone on the proximal row is the scaphoid, which serves as a stabilizing link between the proximal and distal carpal rows. Its name is derived from the Greek word skaphos, which means boat, because of the resemblance in shape. Almost the entire surface articulates with surrounding bones. The distal convex surface articulates with the trapezoid and trapezium. The medial surface has 2 facets. The larger, more distal medial surface is concave and articulates with the capitate. The more proximal medial surface is also concave and articulates the lateral lunate surface. The lateral scaphoid surface is large, convex, and articulates the radius at the scaphoid fossa. The scaphoid tubercle is the only nonarticulating surface and is found distally on the palmar aspect of the scaphoid. This prominence serves as a pivot point for the flexor carpi radialis longus tendon and as an attachment point for the radioscaphocapitate and the scaphotrapeziotrapezoid ligaments. The lunate owes its name to its moonlike configuration. It sits like a cup, holding the capitate (and a small component of the hamate) in its distal biconcave surface. The proximal surface is convex and articulates primarily with the radius and with the discus articularis more medially. The lateral surface articulates with the scaphoid. The angle of inclination between the lateral and proximal surface can vary. The medial surface articulates with the triquetrum. The hornlike palmar and dorsal nonarticulating surfaces serve as ligamentous attachment points and stabilize the head of the capitate in place. The triquetrum also has 4 articulating surfaces. The distal surface has a radial convex and an ulnar concave formation, which both articulate with the hamate. The lateral surface articulates with the lunate and proximally serves as the insertion site for the lunotriquetral interosseous membrane. The small convex proximal surface articulates with the discus articularis. The palmar aspect contains an oval-shaped surface that articulates with the pisiform through cartilaginous structures. The lateral surface is rough and is a site of ligamentous insertion and vascular penetration into the bone. The dorsal triquetrum has a transverse ridge and is the attachment point to the highly relevant dorsal radiotriquetral, dorsal lunotriquetral, and dorsal intercarpal ligaments. The pisiform is a sesamoid type bone that solely articulates with the triquetrum on its small, flat, oval, dorsal articular surface. The remaining surface is round and rough and is the site of attachment for the flexor carpi ulnaris tendon. Ligament fascicles at this site attach the pisiform to the hook of hamate and the base of the fourth and fifth metacarpals. The trapezium has 4 articulating surfaces. The distal saddle-shaped surface articulates with the first metacarpal, while the more ulnar distal surface articulates with the base of the second metacarpal. Medially, the trapezium articulates with the trapezoid and, proximally, with the distal scaphoid. The trapezoid is trapezoidal. Distally, the wedge-shaped facet articulates with the second metacarpal. In some cases, an additional facet may articulate with the third metacarpal. The radial surface articulates with the trapezium, the ulnar surface articulates with the capitate, and the proximal concave surface articulates with the distal scaphoid. The palmar and dorsal aspects receive ligamentous attachments. The capitate is the largest and most prominent bone in the wrist. The proximal head articulates with the scaphoid radially, the hamate ulnarly, and the lunate proximally. The distal body articulates with the trapezoid laterally through cartilage and articulates medially with the hamate through an interosseous ligament. The distal hamate articulates with the styloid process of the third metacarpal, the entire base of the third metacarpal, and, often, the proximal medial facet of the fourth metacarpal. The hamate articulates distally with the fourth and fifth metacarpal bases. The oblique medial surface articulates with the triquetrum, while the lateral surface articulates with the capitate. The palmar nonarticulating projection is known as the hamulus and is the site of attachment of the flexor retinaculum, pisohamatum ligament, and opponens digiti minimi. Ligament anatomy Several ligamentous complexes exist in the wrist. They can be classified as follows:
The palmar ulnocarpal ligaments comprise the other group of capsular ligaments that cross the carpus in a palmar direction. This includes the ulnolunate, ulnotriquetral, and ulnocapitate ligaments. Collectively, they originate from the palmar radioulnar ligament, which contributes to the formation of the triangular fibrocartilage complex. Dorsally, the capsule of the wrist is primarily composed of the dorsal intercarpal and dorsal radiocarpal ligaments. The dorsal radiocarpal ligament connects the radius, lunate, and triquetrum. The dorsal intercarpal ligament connects the triquetrum to the scaphoid and trapezoid. These structures can be bisected together to provide a radial flap when access to the dorsal carpus is required. This technique allows good exposure and results in minimal postoperative scarring and stiffness. The palmar midcarpal ligaments are the main stabilizing ligaments of the carpus and appear as a continuous flat sheet of ligament, which converges at the capitate. Its most important components include the scaphotrapezium, trapezoid, scaphocapitate, triquetrocapitate, triquetrohamate, and pisohamate ligaments. The short ligaments between the bones are known as interosseous ligaments. The interosseous ligaments in the proximal row include the scapholunate, lunotriquetral, and pisotriquetral ligaments. The ligaments in the distal row include the trapeziotrapezoid interosseous ligament, trapeziocapitate interosseous ligament, and capitohamate interosseous ligament. The palmar radioulnar ligament and dorsal radioulnar ligament (which sends fibers to the flexor carpi ulnaris subsheath) contribute to the formation of the triangular fibrocartilage complex. This articular disk is interposed between the ulnar head and carpal bones, and its thickness is inversely proportional to positive ulnar variance. See Kienböck disease in the Pathophysiology section. Blood supply The carpal wrist receives vascularization primarily from the dorsal and palmar carpal plexi (see Image 7). The radial artery, ulnar artery, and posterior branch of the anterior interosseous artery send branches that form the dorsal radiocarpal arch and the dorsal intercarpal arch. The dorsal radiocarpal arch is positioned over and supplies the proximal carpal row, whereas the intercarpal is more distal and supplies the distal carpal arch. In the palmar aspect, the radial and ulnar arteries and the anterior branch of the anterior interosseous artery contribute to the formation of palmar radiocarpal and palmar intercarpal arches. In addition, the deep palmar arch supplies the distal carpal row through the recurrent ulnar and recurrent radial branches. Vascularization at risk The scaphoid is exclusively supplied by the radial artery, which sends a dorsal, proximal, and distal branch to the distal third of the scaphoid (see Image 7). The distal and proximal branches come off the superficial palmar branch of the radial artery (20-30% of scaphoid blood supply), and the distal branch comes off the dorsal radiocarpal branch of the radial artery (70-80% of scaphoid blood supply). These vessels flow retrograde through an interosseous artery to supply the proximal components of the radial artery. For this reason, fractures of the scaphoid waist lead to a severed blood supply and a high incidence of AVN of the proximal pole. The lunate receives blood dorsally and volarly. Dorsally, the radial artery sends small vessels off the intercarpal arch. In the palmar direction, the lunate receives branches from (1) the anterior division of the anterior interosseous artery, (2) the palmar carpal branches of the radial and ulnar arteries, and (3) a recurrent branch from the deep palmar arch. In some instances, the lunate receives vascularization only from the dorsal components and thus is susceptible to AVN after lunate fracture. Gelberman et al found that 20-30% of lunates have a single nutrient vessel that enters the lunate either volarly or dorsally, while the remaining 70-80% have multiple nutrient arteries, shaped in the form of X or Y, that enter the lunate either volarly or dorsally. See Kienböck disease in the Pathophysiology section. The capitate receives blood from branches of the dorsal radiocarpal and interracial arches and dorsal branch of the anterior interosseous. In the palmar aspect, branches are from the palmar radiocarpal arch and deep palmar arch and a direct supply is present from the recurrent ulnar artery. The blood vessels combine to form a plexus distally and supply the head of the capitate through retrograde interosseous vessels. Thus, the proximal capital head is vulnerable to AVN. Innervation The wrist and carpal capsules are innervated by branches of the posterior and anterior interosseous nerves; superficial radial nerve and branch of the superficial radial nerve; dorsal, lateral, and perforating branches of the ulnar nerve; palmar cutaneous of the median nerve; and the posterior and medial cutaneous branches of the forearm. These nerves play a significant role in chronic wrist pain management and denervation procedures. CONTRAINDICATIONSSection 5 of 12
At this time, there are no known absolute contraindications to the initiation of treatment for most wrist fractures and dislocations. WORKUPSection 6 of 12
Imaging Studies
TREATMENTSection 7 of 12
Medical TherapyScaphoid immobilization This includes a thumb spica cast to the interphalangeal joint to inhibit motion at the fracture site. Most include casting to the metacarpophalangeal flexion crease of the palm. A long arm cast just above the elbow is used to prevent supination and pronation. Careful indentation molding over the capitate (dorsally) is used to depress the distal carpal row. Surgical TherapyDistal and Waist FracturesA volar approach is adequate for most fractures. A curvilinear skin incision that crosses the wrist obliquely allows access to the scaphoid tubercle between the radial artery and flexor carpi radialis tendon. The radiocarpal capsule is reflected over the scaphoid tuberosity to the scaphotrapezium joint. If necessary, the fracture is reduced and a K-wire is drilled down one side through the fragments. A Huene jig is used to secure the fragments in proper alignment, and a hole is tapped, followed by fixation using a Herbert screw (see Image 9). Again, alignment is critical, and variations in technique are common. The capsule is repaired, and the skin is closed subcuticularly. Postoperative casting is used for several weeks to confirm stability, although this may result in postoperative stiffness and scarring. Proximal Pole FractureThe dorsal approach allows the best access. The superficial radial nerve is retracted dorsally, and the fascia is divided longitudinally. The radial artery is then retracted volarly. The dorsal carpal branch requires careful attention. Careful ulnar deviation of the wrist then exposes the proximal scaphoid. A K-wire is drilled down the dorsal spine through to the tuberosity. One or two additional parallel K-wires can be used for securement. A 2-mm bit is drilled parallel to the K-wire, and the hole is tapped with a Herbert screw. The screw is overdrilled for full insertion into the scaphoid. Closure and treatment as in the palmar approach completes the procedure. Lunate ImmobilizationApplication of a short arm cast is the most commonly used method of immobilization. No consensus has been reached on the type of cast, length of cast, or period of immobilization needed to prevent nonunion. Operative Acute Lunate FractureOpen reduction of the lunate can be approached either through a dorsal or palmar incision. A K-wire and a Herbert bone screw are used for fixation. Dorsal fractures require repair of the radiotriquetral or dorsal radiolunotriquetral ligaments. Kienböck ProceduresRadial shortening The procedure requires a 10-cm incision over the dorsoradial aspect of the radius. Exposure is gained between the radial artery and flexor carpi radialis. A compression plate and 2 screws are applied to the distal radius. After marking the level of osteotomy, one of the distal screws is removed and rotated away. Two parallel cuts are made approximately 2-3 mm apart. The fragment is removed, the ends are realigned, and the plate is rotated back and secured proximally and distally. After closure, a short arm plaster cast is applied for 4-6 weeks. Revascularization Originally described by Hari in 1979 and modified by others, the efficacy of the procedure remains controversial. A dorsal approach is preferred, with adequate exposure of the lunate. Necrotic bone is curetted and packed with iliac corticocancellous bone. A vascular bone graft pedicle from the second or third metacarpal artery and carpus is then applied. Vascularization from using the posterior interosseous artery and dorsal carpal arch has also been described. Triscaphe (Scaphotrapeziotrapezoid Joint) ArthrodesisThis is fusion of the scaphoid, trapezium, and trapezoid into a single bony unit, while the external dimensions of the original bones are maintained. The procedure begins with a dorsal transverse incision at the radial styloid. The articular and subchondral surfaces of the bone are removed using a rongeur. Two K-wires are passed percutaneously and through the trapezoid. The spacer is placed into the scaphotrapezoid joint, and the scaphoid is reduced (with the wrist in full radial deviation and 45° dorsiflexion) to maintain external dimension of the bones. The pins are driven into the scaphoid, and the spacer is removed. Harvested corticocancellous bone is packed into the joint spaces between the scaphoid, trapezoid, and trapezium. The wrist capsule and extensor retinaculum is realigned and closed without sutures. The pins are cut beneath the skin level, and the skin incisions are closed. A long arm plaster cast is applied with the wrist in slight extension and radial deviation and the elbow at 90°. It is removed in 3-4 weeks. Perilunate Dislocation - Closed Reduction and ImmobilizationThe patient is placed supine, and the elbow is flexed to 90°. Continuous longitudinal traction in fingertraps with 10-15 lb of weight for 10 minutes allows relaxation of the muscles. Manual retraction is applied while the thumb of one hand applies pressure to the volar aspect of the wrist (stabilizing the lunate). The other hand maintains longitudinal traction while extending the wrist. As the wrist is gradually flexed, the capitate can snap back into the concavity of the lunate. Proper cast application requires a 3-point support system with reduction pressure applied at the dorsal capitate, distal radius, and in a palmar direction over the pisiform. Postreduction radiographs are necessary to assess alignment. Perilunate Dislocation - Operative Procedure (ORIF)Numerous combinations of lesser- and greater-arc disruptions are observed, and these require operative modifications based on the injury pattern. Combined palmar and dorsal approach Dorsally, a longitudinal incision is made between the dorsal third and fourth compartment. The extensor retinaculum is elevated, and the extensor pollicis longus is retracted. A longitudinal capsular incision is then performed, and flaps are elevated. Dorsal radiocarpal and intercarpal ligaments are usually preserved. In the palmar aspect, an extended carpal incision is used and the transverse carpal ligaments are incised. The flexor tendons and median nerve are usually retracted radially. Any unreduced component can now be addressed with the aid of longitudinal traction. Again in the palmar aspect, a percutaneous K-wire is placed through the radius into the lunate to maintain reduction. A K-wire is then passed through the lunotriquetral joint. Any disrupted lunotriquetral ligament is then repaired. Next, the midcarpal region is inspected again and further reduction is performed. The scapholunate interosseous ligament is inspected and repaired to the scaphoid (using the ligament rim or with drill holes). Nonabsorbable sutures are used, but they are not tightened until later. Any scaphoid dissociation is reduced, and K-wires are placed in the scaphoid and lunate from lateral to medial, drilling through the scapholunate articulation. The previous suture is tightened, and the carpus is inspected for any further damage. Necessary repair is made to the palmar scapholunate or lunotriquetral ligaments. Incision sites and soft tissue are repaired in the dorsal and palmar aspects. Compression and a long arm splint are applied. Sutures are removed in several days, and a full long arm cast is applied. A short arm cast can be applied at 6 weeks, and pins can be removed at 8 weeks, followed by splint application. Follow-up care with a physiotherapist begins thereafter. Perilunate Fracture DislocationClosed reduction and fixation of these injuries is not recommended. Perilunate Fracture Dislocation - Operative Procedure (ORIF)Transradial styloid fracture Only a dorsal incision is needed. The carpus is entered near the Lister tubercle. The radial styloid is reduced and fixed with K-wires or a screw. The capsule is incised, and the lunate is reduced and pinned to the distal radius. The scaphoid is then reduced and fixed to the lunate. Any necessary repair to the triquetral bone or ligaments is performed last. Transscaphoid perilunate fracture (stage I lesion) A dorsal longitudinal incision is made over the extensor compartments, and soft tissue is retracted. With capsular retraction, the lunate is exposed, reduced, and pinned to the proximal scaphoid with a K-wire. The lunocapitate and lunotriquetral joints are reduced and pinned. Appropriate ligamental repair is made at this time. Next, a distally extended carpal tunnel incision is made, with retraction and exposure of the radial palmar carpal ligaments. If not torn, the radioscaphocapitate and radioscapholunate ligaments are incised. The scaphoid is held with a K-wire. Once alignment is obtained, it is fixed with a Heune jig and a Herbert screw is placed for anatomic alignment (see Image 9). Finally, the injured and iatrogenic ligament disruptions are repaired. A long arm thumb spica cast is recommended for at least 6 weeks, longer for comminuted fractures. Transscaphoid transcapitate (stage II lesion) A similar initial dorsal approach is used as described above. Once the lunate is reduced, no pinning to the scaphoid is necessary. The capitate fracture is reduced, aligned, and percutaneously fixed to maintain alignment. At this point, a Herbert screw is inserted retrograde. The lunate is now pinned to the distal radius. The proximal and distal scaphoid are pinned and fixed with a Herbert screw. A palmar incision is now performed, and palmar radiocarpal ligaments are repaired. Isolated Carpal FracturesTriquetral, pisiform, and hamate fractures heal well with cast immobilization and rarely require surgical intervention. ORIF for hamate fractures is performed with K-wires or screw fixation. ORIF for capitate fractures is performed with the screw inserted proximal to distal. Isolated Carpal DislocationsScaphoid Closed reduction can be attempted with the wrist in traction and pressure over the scaphoid while the wrist is in ulnar deviation. If successful, pin fixation is recommended. Open reduction has the benefit of allowing assessment and repair of the scapholunate interosseous and scaphotrapezium ligaments. A K-wire is fixed to the scaphotrapezium and scapholunate joints. Other Most of the other carpal dislocations require similar operative reduction, K-wire fixation, and ligamental repair. Casting is recommended for 8 weeks. Axial Dislocation and Fracture DislocationTreatment requires proper anesthesia (eg, axial block) and radical debridement of dead tissue. The injury is reduced as much as possible, and further operative intervention is almost always required. Preoperative antibiotics are given. Operative (ORIF) Surgical repair is via a dorsal approach. Further reduction is performed (if required), and K-wires are used to fix the positions. A variety of screws and small plates are used for fixation. Ligamentous structures are salvaged and repaired as much as possible. Then, tendons and neurovascular structures are repaired, often requiring grafts. Loose skin closure with grafting or flap transfer is performed. K-wires remain for 6 weeks, and casting for immobilization remains for even longer. Extensive physiotherapy and occupational therapy is required for full return of function. COMPLICATIONSSection 8 of 12
Scaphoid fracture The first complication encountered with scaphoid fractures is failure to initially recognize and treat the injury. Suboptimal radiographs are usually to blame. This, along with insufficient reduction and inadequate or early mobilization, result in dreaded complications. These include delayed union, nonunion, malunion, AVN of the scaphoid, progressive carpal instability (dorsal intercalated segment instability), and late degenerative changes. Clinically, all manifest as weakness, chronic pain, and limited motion of the hand. Osteosynthetic techniques such as Russe bone grafting and winged grafts during operative repair have been described, with successful prevention of these complications. Operative complications include sensory neuritis, displaced grafts and recurrence of deformity, and carpal collapse from instability after palmar capsule ligament injury. Capsular stiffness after surgery and casting is common but improves with physiotherapy and time. Late salvage procedures include radial styloidectomy, proximal row carpectomy, midcarpal arthrodesis, entire wrist arthrodesis, and scaphoid excision. Lunate fracture The most relevant complication of lunate fractures is associated with the relative difficulty in diagnosing the injury based on findings from simple radiographs. Unrecognized injury and repetitive strain invariably lead to Kienböck disease and, ultimately, arthritic degeneration of the wrist. Tearing of the palmar radiolunate ligament during injury to the proximal pole can result in a dorsal and ulnar shift in the position of the lunate and a palmar tilt of the proximal fragment. Complications such as carpal tunnel syndrome and radiocarpal arthrosis, in addition to nonunion and Kienböck disease, can occur. Important complications of the radial shortening procedures include neurovascular injury and delayed union and nonunion at the osteotomy site. Complications of arthrodesis include infection, hematoma, transient neurapraxia, scapholunate instability, and nonunion. However, these are relatively rare. Perilunate dislocation and fracture dislocation Similar to most carpal injuries, failure to recognize these dislocations and fracture dislocations is the earliest complication. A late presentation of chronic injury may require salvage procedures. Perilunate injury can result in median nerve compression and neuropathy. This usually resolves with reduction, but it may require carpal tunnel release if chronic in nature. AVN of the scaphoid and lunate can occur and is treated within the context of individual injury. The lunate usually has good blood supply, and ischemia is often only transient. The most dreaded complication is carpal instability within or between carpal rows (dissociative and nondissociative) and, ultimately, arthrosis. This requires limited intercarpal arthrosis. Chronic perilunate dislocations are difficult to manage. Early dislocation can be operatively reduced and repaired, but late dislocations may require proximal row carpectomy or wrist arthrodesis. Isolated carpal fractures Complications with triquetral fractures are rare. The most significant concern is ulnar carpal instability. Arthrosis can result from untreated triquetral fracture, and simple excision is suggested. Hamate fractures can be complicated with ulnar neuropathy, tendon rupture, and a weak grip. Complications of capitate fractures include AVN, malrotation of the distal fragment, and arthrosis. Late presentation of trapezoidal dislocation may include AVN. Arthrodesis is recommended over excision because the latter can lead to metacarpal migration and carpal arthritis. Isolated carpal dislocations Most carpal dislocations do well if treated appropriately; complications are rare. Undiagnosed palmar triquetral dislocations can manifest as carpal tunnel syndrome, at which point excision is recommended. Axial dislocation and fracture dislocation Axial fractures and dislocations can be complicated by associated neurovascular, muscular, and tendinous injury. These are more common with axial ulnar dislocation. Later complications, after treatment, include tendon and nerve adhesions, stiff joints, rotational deformities of the finger, fibrous contraction of the thenar eminence (axial radial), and carpal instability. OUTCOME AND PROGNOSISSection 9 of 12
Most wrist injuries have a positive outcome if diagnosed and treated early. Complications and late presentation can lead to devastating degenerative changes in the wrist. FUTURE AND CONTROVERSIESSection 10 of 12
Arthroscopy An important future trend in the management of wrist fractures and dislocation is the use of wrist arthroscopy. This endoscopic technique has been used for diagnostic purposes in the past and has the potential for therapeutic application. This is an active field of study and growth and appears to have tremendous potential. Revascularization Revascularization techniques such as vascular bone grafting for AVN of the scaphoid and lunate have been described and developed by a variety of researchers. Although successes have been reported using these methods, a final consensus has not been reached on the efficacy of these techniques. Salvage Regarding Kienböck disease, researchers have not yet determined which salvage procedure is the most efficacious for end-stage carpal collapse. However, weighing the benefits of pain management versus the loss of function, or vice versa, may ultimately remain the patient's burden. Electrical stimulation Pulsed electromagnetic stimulation with small, implanted electrodes has been described for the treatment of scaphoid nonunion sites. This osteosynthetic technique remains controversial but is advocated by some in instances in which alternate methods of treating nonunion have failed. MULTIMEDIASection 11 of 12
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