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Vol 8, No 4, July/August 2000 225 The treatment of fractures of the scaphoid can be challenging. It can be difficult to initially establish the diagnosis, 1-4 recognize the presence of displacement, 2,5,6 and confirm union. 7 Scaphoid fractures are common among active young adults, many of whom are dependent on their upper extremities for work or sports. Prolonged cast immobilization and activity restriction can be problematic. When a fracture of the scaphoid fails to heal or heals with malalignment, carpal kinematics may be affected; dorsiflex- ion intercalated segment instability of the carpus is seen most frequently. 8-12 The clinical sequelae of nonunion or malunion can include pain, diminished motion and grip strength, and radiocarpal arthrosis. Although many clinical studies have evaluated the results of treatment of fractures of the scaphoid, the data can be difficult to interpret. Most studies do not segregate those fractures most likely to be associated with healing problems (e.g., proximal-pole fractures, displaced fractures, and fractures for which diagnosis and treatment were delayed) from nondisplaced fractures, which generally are not associated with healing problems. The main clinical outcome measure has been union of the fracture. Functional results have been incon- sistently reported. A number of aspects of the management of acute fractures of the scaphoid remain incompletely understood. Displaced fractures of the scaphoid are the most problematic. Most surgeons currently recommend operative treatment. Operative fixation of the scaphoid is also commonly utilized in the treatment of open fractures and perilunate fracture- dislocations. Cast immobilization is usually the appropriate treatment for nondisplaced fractures. However, displacement can be difficult to evaluate on standard radiographs and may be underrecognized. Computed tomography (CT) with reconstructions is useful for detecting displacement. The advantages of internal fixation, which include limited immobilization of the limb and the potential for earlier return to sports and manual labor, make it an ap- pealing option for the treatment of nondisplaced fractures in active individuals. With the advent of percutaneous-screw fixation techniques, some surgeons have begun offering operative fixation to patients who would like to decrease the duration of cast immobilization and possibly avoid it entirely. In particular, competitive athletes and manual laborers are often interested in this treatment option. Dr. Ring is Instructor of Orthopaedic Surgery, Harvard Medical School, Boston, and Director of Research, Hand Surgery Service, Massa- chusetts General Hospital, Boston. Dr. Jupiter is Professor of Orthopaedic Surgery, Harvard Medical School, and Chief, Hand Surgery Service, Department of Orthopaedic Surgery, Massachusetts General Hospital. Dr. Herndon is Chairman, Partners Department of Ortho- paedics, Massachusetts General Hospital. Reprint requests: Dr. Ring, Department of Orthopaedic Surgery, Massachusetts General Hospital, ACC 525, 15 Parkman Street, Boston, MA 02114. Copyright 2000 by the American Academy of Orthopaedic Surgeons. Abstract Nondisplaced fractures of the scaphoid heal with cast immobilization in most cases, but operative treatment is being offered with greater frequency to active patients as an approach to reduce the period of cast immobilization. Computed tomography is more useful for evaluating displacement than standard radiog- raphy. Displaced fractures are at greater risk for nonunion and malunion— both of which have been associated with the development of radiocarpal arthri- tis in long-term studies—and should therefore be treated operatively. Surgical treatment is also recommended for complex fractures (open fractures, perilunate fracture-dislocations, and scaphoid fractures associated with fracture of the distal radius), very proximal fractures, and fractures for which the diagnosis and treatment have been delayed. Operative treatment of fractures of the scaphoid has been simplified by the development of cannulated screws. Internal fixation of fractures of the scaphoid may offer some advantages, including earlier return to athletics or manual labor. J Am Acad Orthop Surg 2000;8:225-231 Acute Fractures of the Scaphoid David Ring, MD, Jesse B. Jupiter, MD, and James H. Herndon, MD, MBA Anatomy The term “scaphoid” is derived from the Greek word for boat. However, some authors have felt that the configuration of the scaphoid more closely resembles a twisted peanut. 2 The complex three-dimensional shape of the scaphoid hinders evaluation of fracture location, the degree of displacement between fragments, and the accuracy of screw or wire placement (Fig. 1). 2,5,6,13,14 Because the surface of the scaphoid is mostly articular, some have recommended that implants placed in the scaphoid be countersunk beneath the surface of the bone. While it is true that any violation of the bone by a screw or wire may injure a joint, it is often possible to leave the head of a screw outside the bone on the volar surface of the distal tubercle of the scaphoid, at the margin of the scaphotrapezial joint, without encountering any adverse effects. This is often done when percutaneous fixation is employed. A consequence of the predominantly articular nature of the surface of the scaphoid is that there are very few potential sites for the entrance of its vascular supply. Anatomic studies of human cadav- eric material have shown that the blood supply to the scaphoid enters primarily through the nonarticular dorsal ridge but also through the distal tubercle. 15 As a result of this anatomic configuration, proximal fractures are more prone to osteonecrosis and nonunion, and a volar operative exposure is less likely to jeopardize the blood supply to the scaphoid than a dorsal exposure. 2 The ability of the intercarpal and radiocarpal ligaments to stabilize the intercalated proximal carpal row is dependent on the integrity of the scaphoid. 8 An unstable scaphoid fracture allows dorsal rotation of the lunate as its liga- mentous attachments to the tri- quetrum become predominant. The proximal pole of the scaphoid rotates with the lunate while the distal pole remains flexed by virtue of its attachments to the trapezium and trapezoid. The result is apex dorsal (and radial) angulation through the fracture of the scaphoid—the so-called humpback deformity. 8 This deformity produces an alteration of carpal kinematics even if the fracture heals. 8,9 Studies in cadavers have demonstrated that deformity of the scaphoid leads to loss of wrist motion, particularly extension. 16 Clinical experience has shown that scaphoid malunion or nonunion may produce carpal malalignment and progressive radiocarpal arthrosis. 8-12,17 These changes are often associated with pain, weak- ness, and diminished motion in the presence of a scaphoid nonunion. The impact of malunion on clinical outcome is less clearly established. Fracture Displacement There are fundamental differences between displaced and nondisplaced fractures of the scaphoid with regard to the risks of nonunion, malunion, and osteonecrosis. 10,18-21 However, the absolute magnitude of these risks remains undetermined. The behavior of nondisplaced fractures is particularly nebulous. Computed tomography may be necessary to precisely identify a fracture as nondisplaced 5,6,14 ; however, this modality is not used routinely. There are also probably a number of active patients who sustain nondisplaced scaphoid fractures but never seek medical attention because they assume they have a wrist injury. Accurate analysis of nondisplaced fractures of the scaphoid would have to account for undiagnosed and untreated injuries—a difficult, if not impossible, task. In a prospective, randomized trial in which long-arm and short- arm thumb spica-cast immobilization were compared, unstable (displaced) fractures of the scaphoid were identified with standard radio- graphy and excluded. 22 Only 2 of 51 fractures (4%) failed to heal, Acute Fractures of the Scaphoid Journal of the American Academy of Orthopaedic Surgeons 226 Figure 1 A, Four views of a right scaphoid demonstrate the complex shape of the scaphoid. The surface is predominantly articular, and most of the blood supply enters through the nonarticular dorsal ridge (LA = lateral apex of the dorsal ridge). The fracture line depicts the pattern of so-called waist fractures. (Adapted with permission from Compson JP: The anatomy of acute scaphoid fractures: A three-dimensional analysis of patterns. J Bone Joint Surg Br 1998;80:218-224.) B, Three-dimensional CT reconstruction of the wrist illustrates radial deviation and volar flexion of the scaphoid (asterisk). (Copyright 1999 by Jesse B. Jupiter, MD.) A B Radial Proximal Volar Dorsal LA LA LA Distal Ulnar * both in the short-arm-cast cohort. This number might have been even lower if CT had been used to identify and exclude displaced fractures. Some authors have even suggested that nondisplaced fractures are inherently stable and will heal with little immobilization. 23 In contrast, displaced fractures have been associated with rates of nonunion and osteonecrosis in ex- cess of 50% and 55%, respective- ly, 20,21 not including the incidence of malunion. 8 Long-term follow-up studies have demonstrated that malunited and especially ununited fractures of the scaphoid can lead to radiocarpal and midcarpal arthrosis with a pattern resembling that observed in patients with injury to the scapholunate interosseous ligament (commonly referred to as scapholunate advanced collapse, or SLAC, wrist). 8-12,17 Consequently, many authors suggest that displaced fractures of the scaphoid should be anatomically reduced and securely fixed 2,18 —recommen- dations that parallel those for other articular fractures. Radiologic Evaluation As a result of the complex shape and orientation of the scaphoid, multiple radiographic views are necessary to accurately image the bone. Posteroanterior views, even those taken in ulnar deviation, are distorted by the flexion and normal curvature of the scaphoid. The proximal pole is well visualized, but most of the anatomic features of the bone, including the distal tubercle, are compressed into the distal half of the radiographic image. The middle third, or waist, of the scaphoid is best seen on the semipronated oblique (45-degree pronated posteroanterior) and lateral views, although overlap of the carpal bones frequently limits the utility of the latter. The distal third of the bone is best seen on the semipronated oblique view. The dorsal ridge is best seen on the semisupi- nated oblique view. Cooney et al 18 defined displacement (or instability) on the basis of the presence of a fracture gap greater than 1 mm on any radiographic projection, a scapholunate angle greater than 60 degrees, or a radiolunate angle greater than 15 degrees. In addition, the intrascaphoid angle should not exceed 35 degrees. 8 Studies performed with the use of CT, 6,14 dry cadaver bones, and methylmethacrylate models of the scaphoid 5 have demonstrated how difficult it is to characterize a fracture of the scaphoid with standard radiographs. Most fractures of the scaphoid need to be evaluated with CT to precisely define the location, pattern, and displacement of the fracture. The CT scan should be obtained in the plane of the scaphoid. Sagittal-plane images are obtained by placing the patient prone in the scanner with the hand over the head, in full pronation and neutral flexion (Fig. 2, A). The sagittal plane of the scaphoid is similar to that defined by the axis of the thumb metacarpal when fully abducted in the plane of the hand. The forearm should be angled approximately 45 degrees across the gantry. For coronal-plane images, the forearm is placed in neutral (Fig. 2, B). Thin (1-mm) sections are obtained. Reconstructed images are not usually necessary. Magnetic resonance imaging is very sensitive for identifying fractures of the scaphoid, even within 48 hours of injury, and has been suggested as an alternative means of establishing the presence or absence of scaphoid injury. 3,25 Unfor- tunately, magnetic resonance imaging is expensive and not always readily available. Computed tomography with thin sections in the plane of the scaphoid holds prom- ise for early detection. Clinical Evaluation When evaluating patients with wrist injuries who have normal radiographs, it is important to keep three principles in mind. First, fracture of the scaphoid is typically an injury of active young adults; therefore, the diagnosis of a fracture of the scaphoid in a patient older than 50 years is suspect. As patients age, the wrist is much more likely to fail at the distal radial metaphysis than at the scaphoid. Second, in addition to palpa- tion of the scaphoid through the interval between the tendons of the first and third dorsal compartments (the anatomic snuffbox), one can palpate the distal tuberosity of the scaphoid volarly. The scaphoid compression test (axial compression of the thumb metacarpal toward the wrist) is a sensitive and specific examination for injury to the scaphoid. Third, as a result of the unusu- ally complex shape of the scaphoid, the radiographic views that best delineate the scaphoid (i.e., posteroanterior views with the wrist in neutral and ulnar deviation, a true lateral view, and 45-degree pronation and supination views) should be obtained before concluding that the examination is negative. 5 A common approach to the management of a suspected fracture of the scaphoid is immobilization of the wrist in a cast or splint for 2 weeks followed by repeat physical and radiographic examination. 2 If the physical examination findings remain suggestive of fracture of the scaphoid but the radiographs are still negative, a bone scan is obtained. 2,24 If there is increased activity in the scaphoid, the injury is treated as a nondisplaced scaphoid fracture. Unfortunately, most patients with suspected fractures have not actually injured the scaphoid, and a large number of patients are over- treated. This is important not only in terms of the cost of unnecessary office visits and radiographs, but David Ring, MD, et al Vol 8, No 4, July/August 2000 227 also because the involved limb in each of these active young patients is disabled for the 2 weeks of immobilization or until a scaphoid fracture is definitively excluded. Treatment Nondisplaced Fractures Computed tomography should be used as the first step to ensure that a fracture is truly nondisplaced. Nondisplaced fractures will nearly always heal in good alignment with cast immobilization. 18,22 A variety of types of casts and durations of immobilization have been utilized, but there is very little solid informa- tion to support one type of cast over another. The tradition of immobi- lizing the thumb, ascribed to the teachings of Bohler, has been aban- doned by some. 1,26 Verdan empha- sized the importance of extending the cast above the elbow and cited cadaver studies demonstrating motion across a scaphoid osteotomy with pronation and supination of the forearm. 3 Arguments have been made in favor of a variety of wrist positions. 1,2 Gellman et al 22 performed a care- fully controlled, randomized prospective study of above-elbow and below-elbow casting techniques. Unstable (displaced) fractures were excluded. The authors detected only a small difference in the incidence of nonunion in favor of an above-elbow cast (0 of 28 in the above-elbow-cast cohort compared with 2 of 23 in the below-elbow-cast cohort). Because the number of patients in the study was small and there were very few adverse out- comes (two nonunions), the observed differences were not statisti- cally significant. Nonetheless, on the basis of these data and personal experience, many physicians con- tinue to use an above-elbow thumb spica cast with the forearm and wrist in neutral position for the first 6 weeks of cast treatment. 2 A below-elbow thumb spica cast is then applied for a minimum of 6 additional weeks or until the fracture is healed. In spite of the relative success of cast immobilization (as measured in terms of the rate of union), there are reasons to consider alternative Acute Fractures of the Scaphoid Journal of the American Academy of Orthopaedic Surgeons 228 A B C D E F Figure 2 Computed tomography of the scaphoid is easier to interpret if the images are obtained in the planes defined by the long axis of the scaphoid. To achieve this, the patient lies prone on the table with the arm overhead. A, For sagittal-plane images, the forearm is held pronated, and the hand lies flat on the table. The forearm crosses the gantry at an angle of approximately 45 degrees (roughly in line with the abducted thumb metacarpal). B, Scout images are obtained to confirm appropriate orientation and to ensure that the entire scaphoid is imaged. Sections are obtained at 1-mm intervals. C, Images obtained in the sagittal plane are best for measuring the intrascaphoid angle. D, For coronal-plane images, the forearm is in neutral rotation. E, Scout images demonstrate the alignment of the wrist through the gantry of the scanner. F, Interpretation of images obtained in the coronal plane is straightforward. (Copyright 1999 by Jesse B. Jupiter, MD.) treatments. Union can be extremely difficult to confirm on standard radiographs. Dias et al 7 asked eight senior observers to evaluate radiographs obtained 12 weeks after scaphoid fracture for the presence or absence of union and found poor interobserver agreement (κ = 0.386). Most patients are initially immo- bilized for 10 to 12 weeks. How- ever, if union is uncertain, the period of immobilization may be extended. The functional consequences of 10 weeks or more of cast immobilization of the wrist have not been well documented, but stiffness and muscle atrophy occur to a variable and often substantial degree. Fur- thermore, fracture of the scaphoid is an injury of active young adults, many of whom are employed as laborers or involved in competitive athletics and would therefore like to avoid prolonged cast immobilization. For athletes, treatment programs have been modified such that standard fiberglass casts are exchanged for soft or padded casts on game days. 27 The soft casts are required to minimize the potential for injury to other athletes. This has not been associated with healing problems provided there is no delay between the injury and diagnosis of the fracture. 27 An alternative approach, particularly for patients who want to return to sports requiring manual dexterity that would be hindered by a cast, has been to perform internal fixation through a volar exposure. In one study, 28 operative fixation of minimally or nondisplaced fractures allowed 12 athletes to return to sports such as basket- ball, baseball, and archery within an average of 6 weeks. Only one fracture in that study failed to heal. The advent of safer, more reli- able implants and operative techniques for percutaneous fixation has decreased the incidence of complications and shortened the duration of recovery associated with operative treatment of nondisplaced fractures. 29 Therefore, we now consider operative treatment more often. Initial percutaneous techniques required temporary Kirschner-wire stabilization followed by predrilling and insertion of a Herbert screw or another non- cannulated screw. The advent of cannulated-screw systems has sub- stantially facilitated percutaneous fixation (Fig. 3). 29 While it is often challenging to achieve optimal placement of the guide wire and verify it with image intensification, once this is achieved, drilling and screw placement are relatively straightforward. Initial data obtained with percutaneous fixation and immediate postoperative mobilization demonstrate that complications are rare, with union rates as high as 100%, excellent functional results, and return to manual labor within 5 weeks. 29 More data are needed to determine the relative merits of operative and nonopera- tive approaches to the treatment of nondisplaced fractures of the scaphoid. David Ring, MD, et al Vol 8, No 4, July/August 2000 229 Figure 3 Radiographs of a 27-year-old man who injured his wrist in a fall while playing tennis. A, Oblique view of the wrist demonstrates a nondisplaced fracture of the waist of the scaphoid. Posteroanterior (B) and lateral (C) radiographs depict fracture fixation with a cannulated 3.0-mm screw inserted by using a percutaneous technique (note that the head of the screw was purposely left outside the bone). (Copyright 1999 by Jesse B. Jupiter, MD.) A B C Displaced Fractures The treatment of displaced fractures of the scaphoid consists of re- alignment of the fracture fragments followed by stable internal fixation. In most cases, volar exposure of the scaphoid will be used in an attempt to limit injury to the blood supply of the scaphoid. 2 It is easier to address very proximal fractures with a dorsal exposure. The Her- bert screw has been a popular device for achieving secure fixation of fractures of the scaphoid. How- ever, using the alignment jig ap- propriately is technically difficult. 30 In addition, some authors have expressed concern that use of the jig may damage the scaphotrapezial joint. 2,30 Cannulated screw fixation, which does not require the use of a jig, has therefore become popular for open as well as percutaneous repairs. It is often useful to insert Kirsch- ner wires into the individual scaphoid fragments so as to allow manip- ulation of the fragments to achieve reduction. These wires are often referred to as “joysticks.” Additional Kirschner wires can be inserted to stabilize the fragments in a reduced position while the wire intended to guide the screw is placed. In patients with fracture comminution, particularly with compromise of the volar cortex, bone grafting should be considered. The position of the screw within the scaphoid may influence healing of the fracture. A recent investiga- tion of screw fixation of nonunited fractures of the scaphoid suggested that the time to healing was shorter when the screw was placed in the central third. 31 Central screw placement was achieved more consis- tently with cannulated screws than with Herbert screws. 31 The rate of success in obtaining a satisfactory reduction with the use of either closed or limited open techniques has yet to be fully evaluated. It may be possible to reduce and fix some displaced fractures by using a percutaneous technique. Fractures of the Proximal Pole of the Scaphoid The perceived difficulty of man- aging fractures of the proximal third of the scaphoid derives primarily from the treatment of nonunited fractures, many of which feature an avascular proximal fragment. There is very little data documenting the behavior of acute fractures of the proximal pole. However, higher risks of nonunion and the need for prolonged immobilization have been reported in a few small series. 26 As a result of these clinical observations and the tenuous vascular supply to the proximal pole observed in cadaver studies, many surgeons favor operative fixation of all fractures of the proximal third of the scaphoid. Initially Unrecognized Fractures Several studies have suggested that a fracture of the scaphoid that is unrecognized, and therefore untreated, for 4 weeks or longer is at increased risk for nonunion. 32,33 The incidence of nonunion with delayed immobilization of scaphoid fractures in several studies ranged from 19% to 88%. 32,33 On the basis of these observations, scaphoid fractures diagnosed on a delayed basis should be considered for operative treatment regardless of displacement. Complicated Fractures of the Scaphoid Fractures of the scaphoid associated with severe soft-tissue injury or open wounds (Fig. 4), associated carpal ligament injuries (perilunate fracture-dislocations, scaphocapitate Acute Fractures of the Scaphoid Journal of the American Academy of Orthopaedic Surgeons 230 Figure 4 Images of a 27-year-old woman who sustained fractures of the scaphoid and capitate with an open wound. A, Radiograph taken in the emergency department suggested severe carpal injury. After debridement of the wound, the injury was defined, and all fractures were secured with screws. B, Intraoperative photo- graph (wrist is at right) shows a screw being placed into the proximal aspect of the capitate (asterisk) through a dorsal wound. C, Postero- anterior radiograph of the wrist demonstrates restoration of alignment of the wrist, with two screws in the scaphoid and one in the capitate. (Copyright 1999 by Jesse B. Jupiter, MD.) A B C * syndrome), or fracture of the distal radius also merit operative treatment. These complicated fractures are high-energy injuries associated with severe soft-tissue damage and swelling; therefore, cast immobilization may not be possible. The goals of treatment in this situation include stable fixation of all skeletal injuries and early initiation of rehabilitation to enhance articular mobility as well as to limit muscle fibrosis, tendon adhesions, and other problems. Summary The treatment of scaphoid fractures is evolving in response to the advent of new imaging techniques and new implants for operative fixation. Fracture displacement and complex wrist injuries are indica- tions for operative treatment. Com- puted tomography may be the best method for characterization of displacement. Some patients with nondisplaced fractures may elect to undergo percutaneous fracture fixation with a cannulated screw to avoid prolonged cast immobilization and to allow a more rapid return to sport or work. David Ring, MD, et al Vol 8, No 4, July/August 2000 231 References 1. Barton NJ: Twenty questions about scaphoid fractures. J Hand Surg [Br] 1992;17:289-310. 2. Gelberman RH, Wolock BS, Siegel DB: Fractures and non-unions of the carpal scaphoid. J Bone Joint Surg Am 1989; 71:1560-1565. 3. Hunter JC, Escobedo EM, Wilson AJ, Hanel DP, Zink-Brody GC, Mann FA: MR imaging of clinically suspected scaphoid fractures. AJR Am J Roentgenol 1997;168:1287-1293. 4. Jacobsen S, Hassani G, Hansen D, Christensen O: Suspected scaphoid fractures: Can we avoid overkill? Acta Orthop Belg 1995;61:74-78. 5. Compson JP: The anatomy of acute scaphoid fractures: A three-dimensional analysis of patterns. J Bone Joint Surg Br 1998;80:218-224. 6. 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