HAND SURGERY COMPLICATIONS
Failure of Open Reduction Internal Fixation of Acute Scaphoid Fractures Eric R. Wagner, MD, Nina Suh, MD, Allen T. Bishop, MD, Alexander Y. Shin, MD THE PATIENT A 35-year-old right-handed woman, nonsmoker, presented to an outside hospital with a minimally displaced scaphoid waist fracture after falling on an outstretched right hand. She underwent percutaneous screw fixation but serial radiographs failed to demonstrate fracture healing and she was referred to our clinic 1 year after the initial operation. The patient had substantial pain in the anatomical snuffbox with any wrist motion. A computed tomography (CT) scan demonstrated a nonunion of the scaphoid waist, mild residual humpback deformity, and early signs of proximal pole osteonecrosis (Fig. 1). Operative management was offered to the patient given her considerable pain, limitations at work and home, and clinical and radiographic findings. THE COMPLICATION Acute scaphoid fractures are the most common carpal bone fracture.1 When scaphoid fractures fail to heal after surgical treatment, careful evaluation of the possible factors should be undertaken. Inadequate fixation, unrecognized carpal collapse or concomitant injuries, and malreduction can all contribute to nonunion of an acute scaphoid fracture. Nonunions can occur secondary to a variety of patient and therapeutic factors. Patient-related factors important to consider include smoking and compliance with postoperative immobilization.2 In addition, accurate diagnosis and a detailed understanding of fracture characteristics and any other associated injuries are From the Department of Orthopedic Surgery, Division of Hand Surgery, Mayo Clinic, Rochester, MN. Received for publication February 6, 2014; accepted in revised form February 21, 2014. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Alexander Y. Shin, MD, Department of Orthopedic Surgery, Division of Hand Surgery, Mayo Clinic, 200 First St. S.W., Rochester, MN 55905; e-mail: [email protected]. 0363-5023/14/---0001$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2014.02.023
crucial. Failure to recognize and address displacement, a vertical oblique fracture pattern, or associated perilunate injury can all lead to nonunion. It is not uncommon for patients to present with an acute injury on a chronic nonunion and misdiagnosed as an acute fracture. Finally, failure to obtain anatomical reduction or correction of a humpback deformity or compromising intraosseous vascularity can predispose to nonunions (Fig. 2). Percutaneous or minimally invasive approaches may also be inappropriate for some fracture patterns. Alternatively, overaggressive fixation with multiple screws might disrupt the fragile blood supply to the fracture site and proximal pole. ADVERSE EFFECTS The rate of scaphoid nonunion ranges from 4% to 50%, depending on the fracture type, displacement, and treatment modality.2e7 Nonunions can be challenging to treat and, when left untreated, have the propensity to develop progressive, predicable arthrosis named scaphoid nonunion advanced collapse (SNAC).4,5,8,9 Mack et al5 demonstrated that scaphoid fracture displacement and associated carpal instability increased the incidence and severity of these degenerative changes. In particular, humpback deformity causes the lunate and proximal pole of the scaphoid to extend with respect to the flexed distal pole. This eventually leads to dorsal intercalated segment instability (DISI). In addition, the disruption of the intraosseous blood supply increases the chance of scaphoid proximal pole collapse. The resultant DISI deformity, proximal pole compromised vascularity, and altered mechanics can lead to chronic, disabling pain, limitation in range of motion, and diminished grip strength. TREATMENT The treatment of scaphoid nonunions after a failed acute surgical intervention is especially challenging. To prevent future degenerative changes and the need for salvage options, it is critical to restore length, stimulate bone healing, and promote revascularization. Although nonsurgical modalities (electrical or ultrasound bone
Ó 2014 ASSH
r
Published by Elsevier, Inc. All rights reserved.
r
1
2
FAILURE OF ORIF FOR ACUTE SCAPHOID FRACTURES
FIGURE 1: The patient. The patient presented with an anatomical snuffbox tenderness 1 year after open reduction internal fixation (ORIF) of an acute scaphoid fracture. The A, B radiographs and C, D CT scans demonstrated a nonunion of the scaphoid waist, mild residual humpback deformity, and early signs of proximal pole osteonecrosis.
stimulation) may have a role in treatment,10 surgical management of scaphoid nonunions after failed surgical treatment is the gold standard if fracture healing is not achieved by 6 months after the injury. Surgical options include nonvascularized allograft or autograft, vascularized bone grafts (pedicled or free), or salvage procedures. Salvage procedures, such as partial J Hand Surg Am.
or complete wrist arthrodesis or proximal row carpectomy, are reserved for patients with degenerative changes. Nonvascularized bone grafts have traditionally been the treatment of choice for scaphoid nonunions. The original technique, reported by Russe,11 involved packing iliac crest corticocancellous bone struts into r
Vol. -, - 2014
FAILURE OF ORIF FOR ACUTE SCAPHOID FRACTURES
3
FIGURE 2: Malreduction. A common error underlying the failure of fixation is malreduction of the fracture, including failure to restore scaphoid length and residual humpback deformity A, fracture fragment opposition (seen on PA and lateral views) B, or translated and malreduced fracture fragments on sagittal (lateral view) and coronal PA view planes (malreduction is easily visualized via CT) C. This can be especially prevalent when attempting to reduce displaced fractures percutaneously.
cavities created within the fracture fragments. Although this technique has had reasonable success, it is difficult to restore the original length in patients with a humpback deformity. An alternative that makes it easier to correct the humpback deformity utilizes an intercalated iliac crest wedge grafting fixed into the nonunion with a screw.6,12,13 Although there are many different techniques for wedge grafting, increased union rates have been demonstrated in these wedge-grafting techniques when compared with the Russe inlay grafting technique.13,14 Vascularized bone grafting has emerged as an important option in the treatment algorithm for scaphoid nonunions, especially in revision procedures, nonunions with osteonecrosis of the proximal pole, and atrophic nonunions. Several options for J Hand Surg Am.
vascularized bone grafting exist including the distal radius, distal ulna, first or second metacarpal, iliac crest, and medial femoral condyle.4,11,14,15 Distal radius and metacarpal bone grafts are both effective sources for vascularized bone without the need for a primary anastomosis, but the amount of bone available is often insufficient to restore the humpback deformity. In cases of severe humpback deformity, free vascularized bone grafting is our preferred method. The two most common sources of free vascularized bone grafts are the medial femoral condyle based on the medial genicular vessels or the iliac crest based on branches from the deep circumflex iliac vessels. Meta-analyses by Merrell et al14 demonstrated a higher union rate in scaphoid nonunions associated with osteonecrosis when using vascularized r
Vol. -, - 2014
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FAILURE OF ORIF FOR ACUTE SCAPHOID FRACTURES
FIGURE 3: Technical errors. Intraoperative surgical errors can also contribute to failure of ORIF of scaphoid fractures, including missed fracture fragments with screw fixation A and B (PA radiograph and CT), intra-articular hardware C (PA radiograph and CT), or overaggressive fixation D.
bone grafts as compared with nonvascularized bone grafts. In our patient, the scaphoid nonunion was treated with a vascularized medial femoral condyle bone graft owing to the humpback deformity, concern of avascularity, and osteonecrosis of the proximal pole of the scaphoid. A volar approach was made to address the nonunion, to restore the carpal deformity, and to place a cannulated headless smooth shaft compression screw. The patient’s wrist was immobilized with a long-arm cast for 6 weeks, then a shortarm cast until healing was confirmed on CT scan. At the last follow-up 2 years after surgery, the patient continued to do well with minimal pain or limitations.
successful in nondisplaced fractures, prolonged cast immobilization often makes this less desirable for patients.16,18e21 Although there does not appear to be a difference in union rate or long-term outcomes between cast immobilization and percutaneous fixation, two randomized controlled trials demonstrated an earlier return to work and, potentially, an earlier time to union18,20 after percutaneous pin fixation. Regardless, surgical treatment is recommended for any displaced or proximal pole fracture. Although the approach (volar vs dorsal) or position of screw (concentric vs eccentric) continue to be debated, it is critical to obtain and maintain an anatomical reduction with the use of a headless compression screw through the axis of the scaphoid. Once a scaphoid fracture nonunion occurs, it should be treated with nonvascularized or vascularized bone grafting. Although excellent union rates have been reported utilizing both techniques, increased union rates with vascularized bone grafting have been demonstrated in nonunions with carpal collapse or proximal pole osteonecrosis.4,6,9,14,15 Furthermore,
LITERATURE REVIEW Increased rates of nonunions are seen in nondisplaced fractures missed or managed without immobilization, displaced fractures larger than 1 mm, proximal pole fractures, early signs of osteonecrosis, humpback deformity, and vertical oblique fractures.2e7,16,17 Although nonsurgical management has been demonstrated to be J Hand Surg Am.
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FAILURE OF ORIF FOR ACUTE SCAPHOID FRACTURES
structural bone grafts, such as nonvascularized or vascularized iliac crest or vascularized medial femoral condyle grafts, should be used in the presence of humpback deformity.4,6,9,12-14,22 If a single screw was used to treat the initial fracture, replacement of it utilizing a slightly different direction may improve fracture stability. The most important goals to consider when treating nonunions are to (1) correct deformity by restoring length and alignment, (2) augment fracture healing, (3) improve vascularity, and (4) obtain compression at the fracture site or through an interposed bone graft.
progression of the deformity and fracture site nonunion. Open treatment of displaced fractures: In recent years, there has been an increasing interest to treat scaphoid fractures using a percutaneous approach in an outpatient setting. This makes anatomical reduction much more difficult in displaced fractures. It also prevents adequate restoration of length and support using bone graft. Furthermore, the percutaneous approach endangers extensor tendons and nerves. Thus, any fracture with displacement noted on the CT scan should be treated with an open approach, with consideration for bone grafting. Intraoperative considerations (screw placement, length): A single compression screw across the fracture site remains the gold standard for scaphoid fracture fixation. However, there is much debate regarding the location of screw concentrically or eccentrically within the scaphoid. Regardless, it is important to maintain the fracture reduction during placement of the screw. It is also critical to avoid screw prominence. One strategy involves careful attention to achieve central screw placement, while subtracting 4 mm from the measured length of the guidewire.23
PREVENTION The risk of scaphoid nonunion after surgical management of acute scaphoid fractures is an important consideration and prevention is imperative (Fig. 3). The following is a list of prevention strategies: Careful evaluation of the initial radiographs:
Any concern for displacement should be evaluated with a CT scan because plain radiographs are often inadequate to visualize displacement or subtle deformity that can effect surgical management. Other associated injuries should also be detected. Appropriate surgical indications and preoperative planning: When deciding nonsurgical versus surgical treatment, the surgeon must consider the displacement, type of fracture, deformity, and any associated degenerative changes. Displaced fractures should be treated utilizing an open approach with a single screw when possible. Increasing humpback deformity or early signs of carpal collapse may necessitate the need for bone graft. Radiocarpal or midcarpal degenerative changes should raise the suspicion for an acute on chronic injury and salvage options must be considered. Adequate fracture reduction: Displaced fractures require anatomical reduction of the fracture fragments and rigid internal fixation in order to achieve direct, primary bone healing and restoration of intraosseous blood supply. Any residual displacement or malreduction results in micromotion and disruption of scaphoid vascularity. Restoration of scaphoid length: Scaphoid length must also be restored with appropriate support. If bony support is lacking, bone grafting is required to maintain the reduction and aid in fracture healing. Failure to correct the humpback deformity or an overwhelming desire to perform a percutaneous approach without bone grafting in patients with humpback deformities will increase the risk for
J Hand Surg Am.
5
REFERENCES 1. Hove LM. Epidemiology of scaphoid fractures in Bergen, Norway. Scand J Plast Reconstr Surg Hand Surg. 1999;33(4):423e426. 2. Szabo RM, Manske D. Displaced fractures of the scaphoid. Clin Orthop Relat Res. 1988;230:30e38. 3. Gellman H, Caputo RJ, Carter V, Aboulafia A, McKay M. Comparison of short and long thumb-spica casts for non-displaced fractures of the carpal scaphoid. J Bone Joint Surg Am. 1989;71(3): 354e357. 4. Kawamura K, Chung KC. Treatment of scaphoid fractures and nonunions. J Hand Surg Am. 2008;33(6):988e997. 5. Mack GR, Bosse MJ, Gelberman RH, Yu E. The natural history of scaphoid non-union. J Bone Joint Surg Am. 1984;66(4):504e509. 6. Meyer C, Chang J, Stern P, Osterman AL, Abzug JM. Complications of distal radial and scaphoid fracture treatment. J Bone Joint Surg Am. 2013;95(16):1517e1526. 7. Steinmann SP, Adams JE. Scaphoid fractures and nonunions: diagnosis and treatment. J Orthop Sci. 2006;11(4):424e431. 8. Vender MI, Watson HK, Wiener BD, Black DM. Degenerative change in symptomatic scaphoid nonunion. J Hand Surg Am. 1987;12(4):514e519. 9. Moon ES, Dy CJ, Derman P, Vance MC, Carlson MG. Management of nonunion following surgical management of scaphoid fractures: current concepts. J Am Acad Orthop Surg. 2013;21(9):548e557. 10. Adams BD, Frykman GK, Taleisnik J. Treatment of scaphoid nonunion with casting and pulsed electromagnetic fields: a study continuation. J Hand Surg Am. 1992;17(5):910e914. 11. Russe O. Fracture of the carpal navicular. Diagnosis, non-operative treatment, and operative treatment. J Bone Joint Surg Am. 1960;42(A): 759e768. 12. Daly K, Gill P, Magnussen PA, Simonis RB. Established nonunion of the scaphoid treated by volar wedge grafting and Herbert screw fixation. J Bone Joint Surg Br. 1996;78(4):530e534.
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FAILURE OF ORIF FOR ACUTE SCAPHOID FRACTURES
19. Dias JJ, Wildin CJ, Bhowal B, Thompson JR. Should acute scaphoid fractures be fixed? A randomized controlled trial. J Bone Joint Surg Am. 2005;87(10):2160e2168. 20. McQueen MM, Gelbke MK, Wakefield A, Will EM, Gaebler C. Percutaneous screw fixation versus conservative treatment for fractures of the waist of the scaphoid: a prospective randomised study. J Bone Joint Surg Br. 2008;90(1):66e71. 21. Skirven T, Trope J. Complications of immobilization. Hand Clin. 1994;10(1):53e61. 22. Chang MA, Bishop AT, Moran SL, Shin AY. The outcomes and complications of 1,2-intercompartmental supraretinacular artery pedicled vascularized bone grafting of scaphoid nonunions. J Hand Surg Am. 2006;31(3):387e396. 23. Bedi A, Jebson PJ, Hayden RJ, Jacobson JA, Martus JE. Internal fixation of acute, nondisplaced scaphoid waist fractures via a limited dorsal approach: an assessment of radiographic and functional outcomes. J Hand Surg Am. 2007;32(3):326e333.
13. Smith BS, Cooney WP. Revision of failed bone grafting for nonunion of the scaphoid. Treatment options and results. Clin Orthop Relat Res. 1996;327:98e109. 14. Merrell GA, Wolfe SW, Slade JF III. Treatment of scaphoid nonunions: quantitative meta-analysis of the literature. J Hand Surg Am. 2002;27(4):685e691. 15. Tambe AD, Cutler L, Stilwell J, Murali SR, Trail IA, Stanley JK. Scaphoid non-union: the role of vascularized grafting in recalcitrant non-unions of the scaphoid. J Hand Surg Br. 2006;31(2):185e190. 16. Cooney WP, Dobyns JH, Linscheid RL. Fractures of the scaphoid: a rational approach to management. Clin Orthop Relat Res. 1980;149: 90e97. 17. Herbert TJ, Fisher WE. Management of the fractured scaphoid using a new bone screw. J Bone Joint Surg Br. 1984;66(1):114e123. 18. Bond CD, Shin AY, McBride MT, Dao KD. Percutaneous screw fixation or cast immobilization for nondisplaced scaphoid fractures. J Bone Joint Surg Am. 2001;83(4):483e488.
J Hand Surg Am.
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Vol. -, - 2014
Failure of Open Reduction Internal Fixation of Acute Scaphoid Fractures Eric R. Wagner, MD, Nina Suh, MD, Allen T. Bishop, MD, Alexander Y. Shin, MD THE PATIENT A 35-year-old right-handed woman, nonsmoker, presented to an outside hospital with a minimally displaced scaphoid waist fracture after falling on an outstretched right hand. She underwent percutaneous screw fixation but serial radiographs failed to demonstrate fracture healing and she was referred to our clinic 1 year after the initial operation. The patient had substantial pain in the anatomical snuffbox with any wrist motion. A computed tomography (CT) scan demonstrated a nonunion of the scaphoid waist, mild residual humpback deformity, and early signs of proximal pole osteonecrosis (Fig. 1). Operative management was offered to the patient given her considerable pain, limitations at work and home, and clinical and radiographic findings. THE COMPLICATION Acute scaphoid fractures are the most common carpal bone fracture.1 When scaphoid fractures fail to heal after surgical treatment, careful evaluation of the possible factors should be undertaken. Inadequate fixation, unrecognized carpal collapse or concomitant injuries, and malreduction can all contribute to nonunion of an acute scaphoid fracture. Nonunions can occur secondary to a variety of patient and therapeutic factors. Patient-related factors important to consider include smoking and compliance with postoperative immobilization.2 In addition, accurate diagnosis and a detailed understanding of fracture characteristics and any other associated injuries are From the Department of Orthopedic Surgery, Division of Hand Surgery, Mayo Clinic, Rochester, MN. Received for publication February 6, 2014; accepted in revised form February 21, 2014. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Alexander Y. Shin, MD, Department of Orthopedic Surgery, Division of Hand Surgery, Mayo Clinic, 200 First St. S.W., Rochester, MN 55905; e-mail: [email protected]. 0363-5023/14/---0001$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2014.02.023
crucial. Failure to recognize and address displacement, a vertical oblique fracture pattern, or associated perilunate injury can all lead to nonunion. It is not uncommon for patients to present with an acute injury on a chronic nonunion and misdiagnosed as an acute fracture. Finally, failure to obtain anatomical reduction or correction of a humpback deformity or compromising intraosseous vascularity can predispose to nonunions (Fig. 2). Percutaneous or minimally invasive approaches may also be inappropriate for some fracture patterns. Alternatively, overaggressive fixation with multiple screws might disrupt the fragile blood supply to the fracture site and proximal pole. ADVERSE EFFECTS The rate of scaphoid nonunion ranges from 4% to 50%, depending on the fracture type, displacement, and treatment modality.2e7 Nonunions can be challenging to treat and, when left untreated, have the propensity to develop progressive, predicable arthrosis named scaphoid nonunion advanced collapse (SNAC).4,5,8,9 Mack et al5 demonstrated that scaphoid fracture displacement and associated carpal instability increased the incidence and severity of these degenerative changes. In particular, humpback deformity causes the lunate and proximal pole of the scaphoid to extend with respect to the flexed distal pole. This eventually leads to dorsal intercalated segment instability (DISI). In addition, the disruption of the intraosseous blood supply increases the chance of scaphoid proximal pole collapse. The resultant DISI deformity, proximal pole compromised vascularity, and altered mechanics can lead to chronic, disabling pain, limitation in range of motion, and diminished grip strength. TREATMENT The treatment of scaphoid nonunions after a failed acute surgical intervention is especially challenging. To prevent future degenerative changes and the need for salvage options, it is critical to restore length, stimulate bone healing, and promote revascularization. Although nonsurgical modalities (electrical or ultrasound bone
Ó 2014 ASSH
r
Published by Elsevier, Inc. All rights reserved.
r
1
2
FAILURE OF ORIF FOR ACUTE SCAPHOID FRACTURES
FIGURE 1: The patient. The patient presented with an anatomical snuffbox tenderness 1 year after open reduction internal fixation (ORIF) of an acute scaphoid fracture. The A, B radiographs and C, D CT scans demonstrated a nonunion of the scaphoid waist, mild residual humpback deformity, and early signs of proximal pole osteonecrosis.
stimulation) may have a role in treatment,10 surgical management of scaphoid nonunions after failed surgical treatment is the gold standard if fracture healing is not achieved by 6 months after the injury. Surgical options include nonvascularized allograft or autograft, vascularized bone grafts (pedicled or free), or salvage procedures. Salvage procedures, such as partial J Hand Surg Am.
or complete wrist arthrodesis or proximal row carpectomy, are reserved for patients with degenerative changes. Nonvascularized bone grafts have traditionally been the treatment of choice for scaphoid nonunions. The original technique, reported by Russe,11 involved packing iliac crest corticocancellous bone struts into r
Vol. -, - 2014
FAILURE OF ORIF FOR ACUTE SCAPHOID FRACTURES
3
FIGURE 2: Malreduction. A common error underlying the failure of fixation is malreduction of the fracture, including failure to restore scaphoid length and residual humpback deformity A, fracture fragment opposition (seen on PA and lateral views) B, or translated and malreduced fracture fragments on sagittal (lateral view) and coronal PA view planes (malreduction is easily visualized via CT) C. This can be especially prevalent when attempting to reduce displaced fractures percutaneously.
cavities created within the fracture fragments. Although this technique has had reasonable success, it is difficult to restore the original length in patients with a humpback deformity. An alternative that makes it easier to correct the humpback deformity utilizes an intercalated iliac crest wedge grafting fixed into the nonunion with a screw.6,12,13 Although there are many different techniques for wedge grafting, increased union rates have been demonstrated in these wedge-grafting techniques when compared with the Russe inlay grafting technique.13,14 Vascularized bone grafting has emerged as an important option in the treatment algorithm for scaphoid nonunions, especially in revision procedures, nonunions with osteonecrosis of the proximal pole, and atrophic nonunions. Several options for J Hand Surg Am.
vascularized bone grafting exist including the distal radius, distal ulna, first or second metacarpal, iliac crest, and medial femoral condyle.4,11,14,15 Distal radius and metacarpal bone grafts are both effective sources for vascularized bone without the need for a primary anastomosis, but the amount of bone available is often insufficient to restore the humpback deformity. In cases of severe humpback deformity, free vascularized bone grafting is our preferred method. The two most common sources of free vascularized bone grafts are the medial femoral condyle based on the medial genicular vessels or the iliac crest based on branches from the deep circumflex iliac vessels. Meta-analyses by Merrell et al14 demonstrated a higher union rate in scaphoid nonunions associated with osteonecrosis when using vascularized r
Vol. -, - 2014
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FAILURE OF ORIF FOR ACUTE SCAPHOID FRACTURES
FIGURE 3: Technical errors. Intraoperative surgical errors can also contribute to failure of ORIF of scaphoid fractures, including missed fracture fragments with screw fixation A and B (PA radiograph and CT), intra-articular hardware C (PA radiograph and CT), or overaggressive fixation D.
bone grafts as compared with nonvascularized bone grafts. In our patient, the scaphoid nonunion was treated with a vascularized medial femoral condyle bone graft owing to the humpback deformity, concern of avascularity, and osteonecrosis of the proximal pole of the scaphoid. A volar approach was made to address the nonunion, to restore the carpal deformity, and to place a cannulated headless smooth shaft compression screw. The patient’s wrist was immobilized with a long-arm cast for 6 weeks, then a shortarm cast until healing was confirmed on CT scan. At the last follow-up 2 years after surgery, the patient continued to do well with minimal pain or limitations.
successful in nondisplaced fractures, prolonged cast immobilization often makes this less desirable for patients.16,18e21 Although there does not appear to be a difference in union rate or long-term outcomes between cast immobilization and percutaneous fixation, two randomized controlled trials demonstrated an earlier return to work and, potentially, an earlier time to union18,20 after percutaneous pin fixation. Regardless, surgical treatment is recommended for any displaced or proximal pole fracture. Although the approach (volar vs dorsal) or position of screw (concentric vs eccentric) continue to be debated, it is critical to obtain and maintain an anatomical reduction with the use of a headless compression screw through the axis of the scaphoid. Once a scaphoid fracture nonunion occurs, it should be treated with nonvascularized or vascularized bone grafting. Although excellent union rates have been reported utilizing both techniques, increased union rates with vascularized bone grafting have been demonstrated in nonunions with carpal collapse or proximal pole osteonecrosis.4,6,9,14,15 Furthermore,
LITERATURE REVIEW Increased rates of nonunions are seen in nondisplaced fractures missed or managed without immobilization, displaced fractures larger than 1 mm, proximal pole fractures, early signs of osteonecrosis, humpback deformity, and vertical oblique fractures.2e7,16,17 Although nonsurgical management has been demonstrated to be J Hand Surg Am.
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FAILURE OF ORIF FOR ACUTE SCAPHOID FRACTURES
structural bone grafts, such as nonvascularized or vascularized iliac crest or vascularized medial femoral condyle grafts, should be used in the presence of humpback deformity.4,6,9,12-14,22 If a single screw was used to treat the initial fracture, replacement of it utilizing a slightly different direction may improve fracture stability. The most important goals to consider when treating nonunions are to (1) correct deformity by restoring length and alignment, (2) augment fracture healing, (3) improve vascularity, and (4) obtain compression at the fracture site or through an interposed bone graft.
progression of the deformity and fracture site nonunion. Open treatment of displaced fractures: In recent years, there has been an increasing interest to treat scaphoid fractures using a percutaneous approach in an outpatient setting. This makes anatomical reduction much more difficult in displaced fractures. It also prevents adequate restoration of length and support using bone graft. Furthermore, the percutaneous approach endangers extensor tendons and nerves. Thus, any fracture with displacement noted on the CT scan should be treated with an open approach, with consideration for bone grafting. Intraoperative considerations (screw placement, length): A single compression screw across the fracture site remains the gold standard for scaphoid fracture fixation. However, there is much debate regarding the location of screw concentrically or eccentrically within the scaphoid. Regardless, it is important to maintain the fracture reduction during placement of the screw. It is also critical to avoid screw prominence. One strategy involves careful attention to achieve central screw placement, while subtracting 4 mm from the measured length of the guidewire.23
PREVENTION The risk of scaphoid nonunion after surgical management of acute scaphoid fractures is an important consideration and prevention is imperative (Fig. 3). The following is a list of prevention strategies: Careful evaluation of the initial radiographs:
Any concern for displacement should be evaluated with a CT scan because plain radiographs are often inadequate to visualize displacement or subtle deformity that can effect surgical management. Other associated injuries should also be detected. Appropriate surgical indications and preoperative planning: When deciding nonsurgical versus surgical treatment, the surgeon must consider the displacement, type of fracture, deformity, and any associated degenerative changes. Displaced fractures should be treated utilizing an open approach with a single screw when possible. Increasing humpback deformity or early signs of carpal collapse may necessitate the need for bone graft. Radiocarpal or midcarpal degenerative changes should raise the suspicion for an acute on chronic injury and salvage options must be considered. Adequate fracture reduction: Displaced fractures require anatomical reduction of the fracture fragments and rigid internal fixation in order to achieve direct, primary bone healing and restoration of intraosseous blood supply. Any residual displacement or malreduction results in micromotion and disruption of scaphoid vascularity. Restoration of scaphoid length: Scaphoid length must also be restored with appropriate support. If bony support is lacking, bone grafting is required to maintain the reduction and aid in fracture healing. Failure to correct the humpback deformity or an overwhelming desire to perform a percutaneous approach without bone grafting in patients with humpback deformities will increase the risk for
J Hand Surg Am.
5
REFERENCES 1. Hove LM. Epidemiology of scaphoid fractures in Bergen, Norway. Scand J Plast Reconstr Surg Hand Surg. 1999;33(4):423e426. 2. Szabo RM, Manske D. Displaced fractures of the scaphoid. Clin Orthop Relat Res. 1988;230:30e38. 3. Gellman H, Caputo RJ, Carter V, Aboulafia A, McKay M. Comparison of short and long thumb-spica casts for non-displaced fractures of the carpal scaphoid. J Bone Joint Surg Am. 1989;71(3): 354e357. 4. Kawamura K, Chung KC. Treatment of scaphoid fractures and nonunions. J Hand Surg Am. 2008;33(6):988e997. 5. Mack GR, Bosse MJ, Gelberman RH, Yu E. The natural history of scaphoid non-union. J Bone Joint Surg Am. 1984;66(4):504e509. 6. Meyer C, Chang J, Stern P, Osterman AL, Abzug JM. Complications of distal radial and scaphoid fracture treatment. J Bone Joint Surg Am. 2013;95(16):1517e1526. 7. Steinmann SP, Adams JE. Scaphoid fractures and nonunions: diagnosis and treatment. J Orthop Sci. 2006;11(4):424e431. 8. Vender MI, Watson HK, Wiener BD, Black DM. Degenerative change in symptomatic scaphoid nonunion. J Hand Surg Am. 1987;12(4):514e519. 9. Moon ES, Dy CJ, Derman P, Vance MC, Carlson MG. Management of nonunion following surgical management of scaphoid fractures: current concepts. J Am Acad Orthop Surg. 2013;21(9):548e557. 10. Adams BD, Frykman GK, Taleisnik J. Treatment of scaphoid nonunion with casting and pulsed electromagnetic fields: a study continuation. J Hand Surg Am. 1992;17(5):910e914. 11. Russe O. Fracture of the carpal navicular. Diagnosis, non-operative treatment, and operative treatment. J Bone Joint Surg Am. 1960;42(A): 759e768. 12. Daly K, Gill P, Magnussen PA, Simonis RB. Established nonunion of the scaphoid treated by volar wedge grafting and Herbert screw fixation. J Bone Joint Surg Br. 1996;78(4):530e534.
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FAILURE OF ORIF FOR ACUTE SCAPHOID FRACTURES
19. Dias JJ, Wildin CJ, Bhowal B, Thompson JR. Should acute scaphoid fractures be fixed? A randomized controlled trial. J Bone Joint Surg Am. 2005;87(10):2160e2168. 20. McQueen MM, Gelbke MK, Wakefield A, Will EM, Gaebler C. Percutaneous screw fixation versus conservative treatment for fractures of the waist of the scaphoid: a prospective randomised study. J Bone Joint Surg Br. 2008;90(1):66e71. 21. Skirven T, Trope J. Complications of immobilization. Hand Clin. 1994;10(1):53e61. 22. Chang MA, Bishop AT, Moran SL, Shin AY. The outcomes and complications of 1,2-intercompartmental supraretinacular artery pedicled vascularized bone grafting of scaphoid nonunions. J Hand Surg Am. 2006;31(3):387e396. 23. Bedi A, Jebson PJ, Hayden RJ, Jacobson JA, Martus JE. Internal fixation of acute, nondisplaced scaphoid waist fractures via a limited dorsal approach: an assessment of radiographic and functional outcomes. J Hand Surg Am. 2007;32(3):326e333.
13. Smith BS, Cooney WP. Revision of failed bone grafting for nonunion of the scaphoid. Treatment options and results. Clin Orthop Relat Res. 1996;327:98e109. 14. Merrell GA, Wolfe SW, Slade JF III. Treatment of scaphoid nonunions: quantitative meta-analysis of the literature. J Hand Surg Am. 2002;27(4):685e691. 15. Tambe AD, Cutler L, Stilwell J, Murali SR, Trail IA, Stanley JK. Scaphoid non-union: the role of vascularized grafting in recalcitrant non-unions of the scaphoid. J Hand Surg Br. 2006;31(2):185e190. 16. Cooney WP, Dobyns JH, Linscheid RL. Fractures of the scaphoid: a rational approach to management. Clin Orthop Relat Res. 1980;149: 90e97. 17. Herbert TJ, Fisher WE. Management of the fractured scaphoid using a new bone screw. J Bone Joint Surg Br. 1984;66(1):114e123. 18. Bond CD, Shin AY, McBride MT, Dao KD. Percutaneous screw fixation or cast immobilization for nondisplaced scaphoid fractures. J Bone Joint Surg Am. 2001;83(4):483e488.
J Hand Surg Am.
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