- Email: [email protected]
Role of Vascularized Bone Grafts in the Treatment of Scaphoid Nonunions Associated With Proximal Pole Avascular Necrosis and Carpal Collapse
IN BRIEF
Role of Vascularized Bone Grafts in the Treatment of Scaphoid Nonunions Associated With Proximal Pole Avascular Necrosis and Carpal Collapse Sanjeev Kakar, MD, Allen T. Bishop, MD, Alexander Y. Shin, MD scaphoid nonunion has been estimated to be approximately 15%1 and can be related to a delay in diagnosis and treatment, proximal location of the fracture, displacement greater than 1 mm, and carpal instability.2– 4 Left untreated, these wrists often undergo progressive, predictable degenerative changes also known as scaphoid nonunion advanced collapse.5,6 Avascular necrosis (AVN) of the scaphoid occurs in an estimated 3% of all scaphoid fractures.7 Predominantly seen within the proximal pole, the etiology has been attributed to the retrograde intraosseous blood supply of the scaphoid. Plain radiographic signs of AVN include sclerosis of the proximal pole with occasional fragmentation and collapse. Computed tomography scans can effectively demonstrate collapse and bony characteristics of the nonunion, including resorptive findings, sclerosis, narrowing of joint spaces, and fragmentation.8 Magnetic resonance imaging (MRI) has been recommended to assess the vascularity of the proximal pole. Standard MRI has been shown to have an accuracy of 68%, which increases to 83% when gadolinium-enhanced MRI is used.9 Despite this, many surgeons rely solely on this modality, which only measures edema within the bone, not the actual blood flow. Currently, the only definitive method to determine vascularity of the proximal pole is direct intraoperative assessment to determine absence or presence of punctate bleeding of the proximal fragment, as was described by Green in 1985.10
T
HE INCIDENCE OF
In Brief
From the Department of Orthopaedic Surgery, Mayo Clinic, Rochester, MN. Received for publication October 15, 2010; accepted in revised form October 17, 2010. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Correspondingauthor:AlexanderY.Shin,MD,DepartmentofOrthopaedicSurgery,MayoClinic, 200 1st Street SW, Rochester, MN 55905; e-mail: [email protected]. 0363-5023/11/36A04-0031$36.00/0 doi:10.1016/j.jhsa.2010.10.015
722 䉬 © ASSH 䉬 Published by Elsevier, Inc. All rights reserved.
USE OF VASCULARIZED BONE GRAFTS IN THE TREATMENT OF SCAPHOID NONUNIONS Numerous techniques have been devised in the treatment of scaphoid nonunion with AVN of the proximal pole, such as the use of nonvascularized autografts including but not limited to anterior iliac crest and distal radius corticocancellous grafts.11,12 With a reported success rate of only 40% to 67%,13,14 these grafts have been less favored than pedicled vascularized bone grafts (VBGs), which have a union rate between 88% and 91%.2,15 With greater than 90% of the osteocytes surviving the transplantation procedure, graft-host union or revascularization occurs much more rapidly without substantial bone resorption or creeping substitution of necrotic bone that is seen with nonvascularized grafts.16 Based on the 1,2-intercompartmental supraretinacular artery (ICSRA), pedicled VBGs from the distal radius have been successfully used in the treatment of scaphoid nonunions. Zaidemberg et al.17 reported on the use of the ascending irrigating branch of the radial artery, which was essentially the 1,2-ICSRA vessel. They reported a 100% union rate in 11 chronic scaphoid nonunions at an average of 6 weeks, with improvements in rest pain and grip strength in all patients. Steinmann and colleagues18 treated 14 patients with the 1,2ICSRA and noted that all patients healed at an average of 11 weeks and 9 had good to excellent results. Patients with early arthritic changes were noted to have poorer outcomes than those without evidence of degeneration. Waitayawinyu et al.19 reported on 30 patients with established scaphoid nonunion, proximal pole AVN, and no previous surgery, who were treated with open reduction and internal fixation of the fracture and 1,2-ICSRA VBGs. Time to union was on average 5.1 months, with a success rate of 93%. Patients were found to have improved grip strength, satisfaction scores, and scaphoid height to length ratios, and 93% returned to preinjury work or sports activity. Sim-
723
compared with a 12 of 12 union rate after 13 weeks in ilar favorable results were reported by Tsai and 20 21 patients treated with an MFC graft (p ⬍ .001). colleagues and Waters and Stewart. Despite The MFC graft offers several advantages in the setthese promising studies, others have reported less ting of combined AVN and scaphoid humpback deforthan favorable results. In treating patients with proximal mity. The vascularity is robust and consistent, facilitatpole nonunions with AVN, Boyer et al.22 noted union ing harvest and microvascular anastomosis.24,25 Large in only 60% of patients. Similarly disappointing results 23 grafts can easily be obtained from the medial femoral were reported by Straw et al., with only 2 of 16 nonunions with AVN of the condyle and can be manipuEDUCATIONAL OBJECTIVES proximal pole united with lated to fit the defect with the 1,2-ICSRA VBGs. In a ● Discuss the diagnosis of methods to determine the vascularity of the prox- less risk of possible torsion imal scaphoid pole. critical review of results or damage to the vascular from a single institution, ● Describe the 1,2-intercompartmental supraretinacular artery (ICSRA) vas- pedicle. In addition, the cularized bone graft. Chang et al.13 determined quality of the cancellous that successful outcome us- ● State the advantages and disadvantages of the ICSRA for the treatment of bone quality is excellent ing the 1,2-ICSRA was not and provides greater strucproximal scaphoid pole avascular necrosis. universal and depended on ● Summarize the results of the ICSRA in the treatment of proximal scaphoid tural rigidity compared with careful patient selection and grafts harvested from the pole avascular necrosis. fracture selection. A total of ● Discuss the location and anatomy of the medial femoral condyle vascular distal radius. This tech48 patients with scaphoid nique is demanding and rebone graft for proximal scaphoid pole avascular necrosis. nonunions and/or osteone- ● Compare and contrast the ICSRA versus the medial femoral condyle vas- quires exceptional attention crosis were observed for an to detail in the insetting and cular bone graft for proximal scaphoid pole avascular necrosis. average of 7.8 months after fixation of the graft as well fracture fixation and 1,2- Earn up to 2 hours of CME credit per JHS issue when you read the related as the microsurgical anastoICSRA VBG. Union oc- articles and take the online test. To pay the $20 fee and take this month’s moses of the vessels to the curred in 71% of patients test, visit http://www.assh.org/professionals/jhs. radial artery and venae cowith scaphoid nonunion and mitantes. in 50% with AVN. Of the 14 failures, 9 were in patients with humpback deformity of the scaphoid and dorsal USE OF MEDIAL FEMORAL CONDYLE GRAFTS intercalated segment instability. In these patients, thereIN THE TREATMENT OF SCAPHOID NONUNIONS fore, restoration of normal scaphoid geometry with a Indications vascularized structural graft may need to be performed The primary indication for the use of the MFC is in the to enhance union and permit normal carpal kinematics. 12 correction of scaphoid nonunions associated with both As emphasized by Fisk nearly 30 years ago, reshumpback deformity of the scaphoid and AVN of the toration of carpal geometry was essential in obtaining proximal pole. The former is defined as a lateral intraunion of scaphoid nonunions associated with carpal scaphoid angle of 45° or greater (normal ⱕ35°). It is collapse. In our experience, however, we found that the often associated with dorsal intercalated segment instavascularized grafts obtained from the 1,2-ICSRA are bility deformity of the lunate, defined as a revised carpal limited in terms of the size and length of the pedicle to height ratio of 1.52 or less (normal ⫽ 1.57 ⫾ 0.05) or sufficiently correct the humpback deformity. A free radiolunate angle of 15° or greater (normal ⱕ10°). VBG that could provide a large VBG with a long Avascular necrosis can be detected by evidence of vascular pedicle was sought. The medial femoral consclerotic changes and/or cyst formation of the proximal dyle VBG, which was previously used as a corticopepole on radiographs or computed tomography scans. riosteal graft, was modified based on anatomic studMagnetic resonance imaging may be helpful in trying to ies24 –26 and a surgical technique was developed to elucidate diminished flow within the proximal pole of apply this VBG to scaphoid nonunions with AVN and 27 the scaphoid as evidenced by low signal intensity on carpal collapse. The results of this medial femoral both T1 and T2, and diminished uptake of contrast with condyle (MFC) VBG was reported by Jones et al.,28 gadolinium-enhanced MRI. 9 In our experience, howwho compared the outcomes of patients with scaphoid ever, we have found MRI to be unpredictable in assesswaist nonunions with AVN of the proximal pole with ing blood flow within the scaphoid, particularly in the carpal collapse treated with either a 1,2-ICSRA or MFC previous surgical scaphoid nonunion, and always conVBG. In patients treated with the 1,2-ICSRA grafts, 4 of 10 fractures healed at a median time of 19 weeks firm avascularity intraoperatively by the appearance of JHS 䉬 Vol A, April
In Brief
VASCULARIZED BONE GRAFT FOR SCAPHOID NONUNION
724
VASCULARIZED BONE GRAFT FOR SCAPHOID NONUNION
white sclerotic bone with absent punctate bleeding on tourniquet release as recommended by Green.10
In Brief
Contraindications Nondisplaced or minimally displaced scaphoid nonunions with AVN of the proximal pole but without humpback deformity are treated with an inlay VBG such as those based on the 1,2-ICSRA, the volar radius blood supply, or free iliac crest VBG.29 –31 In cases in which there is scaphoid humpback deformity without AVN, we advocate the use of nonvascularized wedge grafts such as the iliac crest and open reduction and internal fixation of the fracture.32 When there is evidence of radioscaphoid arthritic changes or advanced scaphoid nonunion, advanced collapse degenerative joint disease, consideration of salvage procedures including wrist denervation, scaphoid excision and 4-corner fusion, proximal row carpectomy, or complete wrist fusion must be made. Scaphoid nonunions complicated with humpback deformity and AVN of the proximal pole remain a challenging clinical scenario. This subset of patients has frequently been grouped together with those without AVN or collapse, making comparison of treatment outcomes difficult or impossible. However, careful analysis has demonstrated that failure to address both the structural and vascular deficiencies yields disappointing outcomes.2,13,28 A majority of pedicled VBGs from the distal radius have been described as inlay grafts. When pedicled VBGs from the distal radius are used as an interposition VBG to correct carpal malalignment, these grafts often fail to adequately restore scaphoid foreshortening resulting from the limited amount of bone that can be harvested as well as the quality of the bone, which leads to poor results. In contrast, free medial femoral condyle VBGs can provide not only structural support, but also a consistent and robust blood supply that results in excellent rates of union with restoration of scaphoid geometry and restoration of function.28 From our experience, the MFC graft provides both a robust and consistent vascular supply and optimal density of mostly cancellous bone from which large grafts (up to 1.5 cm3) can be harvested and shaped to fit the scaphoid defect with minimal donor site morbidity, and should be considered in the unique setting of a scaphoid nonunion with proximal pole AVN and carpal collapse. REFERENCES 1. Kuschner SH, Lane CS, Brien WW, Gellman H. Scaphoid fractures and scaphoid nonunion. Diagnosis and treatment. Orthop Rev 1994; 23:861– 871. 2. Merrell GA, Wolfe SW, Slade JF III. Treatment of scaphoid nonunions: quantitative meta-analysis of the literature. J Hand Surg 2002;27A:685– 691.
3. Pao VS, Chang J. Scaphoid nonunion: diagnosis and treatment. Plast Reconstr Surg 2003;112:1666 –1676, quiz 1677, discussion 1678 – 1679. 4. Trumble TE, Salas P, Barthel T, Robert KQ III. Management of scaphoid nonunions. J Am Acad Orthop Surg 2003;11:380 –391. 5. Mack GR, Bosse MJ, Gelberman RH, Yu E. The natural history of scaphoid nonunion. J Bone Joint Surg 1984;66A:504 –509. 6. Ruby LK, Stinson J, Belsky MR. The natural history of scaphoid nonunion. J Bone Joint Surg 1985;67A:428 – 432. 7. Eisenhauer MA. In: Marx JA, Hockenberger HS, Walls RM, eds. Rosen’s emergency medicine: concepts and clinical practice. 5th ed. St Louis, MO: Mosby, 2002:536 –555. 8. Smith ML, Bain GI, Chabrel N, Turner P, Carter C, Field J. Using computer tomography to assist with diagnosis of avascular necrosis complicating chronic scaphoid nonunion. J Hand Surg 2009;34A: 1037–1043. 9. Cerezal L, Abascal F, Canga A, Garcia-Valtuille R, Bustamante M, del Pinal F. Usefulness of gadolinium enhanced MR imaging in the evaluation of the vascularity of scaphoid nonunions. AJR Am J Roentgenol 2000;174:141–149. 10. Green DP. The effect of avascular necrosis on Russe bone grafting for scaphoid nonunion. J Hand Surg 1985;10A:597– 605. 11. Fernandez DL. Anterior bone grafting and conventional lag screw fixation to treat scaphoid nonunions. J Hand Surg 1990;15A:140 –147. 12. Fisk GR. Carpal instability and the fractured scaphoid. Ann R Coll Surg Engl 1970;46:63–76. 13. 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 2006;31A:387–396. 14. Krimmer H. Management of acute fractures and nonunions of the proximal pole of the scaphoid. J Hand Surg 2002;27B:245–248. 15. Munk B, Larsen CF. Bone grafting the scaphoid nonunion. A systematic review of 147 publications including 5246 cases of scaphoid nonunion. Acta Orthop Scand 2004;75:618 – 629. 16. Goldberg VM, Shaffer JW, Field G, Davy DT. Biology of vascularized bone grafts. Orthop Clin North Am 1987;18:179 –185. 17. Zaidemberg C, Siebert JW, Angrigiani C. A new vascularized bone graft for scaphoid nonunion. J Hand Surg 1991;16A:474 – 478. 18. Steinmann SP, Bishop AT, Berger RA. Use of the 1,2 intercompartmental supraretinacular artery as a vascularized pedicle bone graft for difficult scaphoid nonunion. J Hand Surg 2002;27A:391– 401. 19. Waitayawinyu T, McCallister WV, Katolik LI, Schlenker JD, Trumble TE. Outcome after vascularized bone grafting of scaphoid nonunions with avascular necrosis. J Hand Surg 2009;34A:387–394. 20. Tsai TT, Chao EK, Tu YK, Chen AC, Lee MS, Ueng SW. Management of scaphoid nonunion with avascular necrosis using 1,2 intercompartmental supraretinacular arterial bone grafts. Chang Gung Med J 2002;25:321–328. 21. Waters PM, Stewart SL. Surgical treatment of nonunion and avascular necrosis of the proximal part of the scaphoid in adolescents. J Bone J Surg 2002;84A:915–920. 22. Boyer MI, von Schroeder HP, Axelrod TS. Scaphoid nonunion with avascular necrosis of the proximal pole. Treatment with a vascularized bone graft from the dorsum of the distal radius. J Hand Surg 1998;23B:686 – 690. 23. Straw RG, Davis TR, Dias JJ. Scaphoid nonunion: treatment with a pedicled vascularized bone graft based on the 1,2 intercompartmental supraretinacular branch of the radial artery. J Hand Surg 2002; 27B:413– 416. 24. Doi K, Sakai K. Vascularized periosteal bone graft from the supracondylar region of the femur. Microsurgery 1994;15:305–315. 25. Sakai K, Doi K, Kawai S. Free vascularized thin corticoperiosteal graft. Plast Reconstr Surg 1991;87:290 –298. 26. Yamamoto H, Jones DB Jr, Moran SL, Bishop AT, Shin AY. The arterial anatomy of the medial femoral condyle and its clinical implications. J Hand Surg 2010;l35B:569 –574. 27. Larson AN, Bishop AT, Shin AY. Free medial femoral condyle bone
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grafting for scaphoid nonunions with humpback deformity and proximal pole avascular necrosis. Tech Hand Upper Extrem Surg 2007;11:246–258. 28. Jones DB Jr, Burger H, Bishop AT, Shin AY. Treatment of scaphoid waist nonunions with an avascular proximal pole and carpal collapse. A comparison of two vascularized bone grafts. J Bone Joint Surg 2008;90A:2616 –2625. 29. Mathoulin C, Haerle M. Vascularized bone graft from the palmar carpal artery for treatment of scaphoid nonunion. J Hand Surg 1998;23B:318 –323.
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30. Mathoulin C, Haerle M, Vandeputte G. Vascularized bone graft in carpal bone reconstruction. Ann Chir Plast Esthet 2005;50: 43– 48. 31. Harpf C, Gabl M, Reinhart C. Small free vascularized iliac crest bone grafts in reconstruction of the scaphoid bone: a retrospective study in 60 cases. Plast Reconstr Surg 2001;108:664 – 674. 32. Fernandez DL, Eggli S. Nonunion of the scaphoid. Revascularization of the proximal pole with implantation of a vascular bundle and bone grafting. J Bone J Surg 1995;6:883– 893.
JOURNAL CME QUESTIONS
What is the definitive method to determine vascularity of the proximal scaphoid pole? a. Magnetic resonance imaging (MRI) b. Gadolinium-enhanced MRI c. Computerized tomography d. Intraoperative assessment e. Bone scan
What is the primary indication for the use of medial femoral condyle vascular bone graft in the correction of scaphoid nonunions? a. Scaphoid nonunions with a humpback deformity of the scaphoid and with avascular necrosis (AVN) of the proximal pole b. Scaphoid nonunions without a humpback deformity of the scaphoid and with AVN of the proximal pole trunk c. Scaphoid nonunions without a humpback deformity of the scaphoid and without AVN of the proximal pole trunk d. Scaphoid nonunions with a humpback deformity of the scaphoid and without AVN of the proximal pole trunk e. All scaphoid nonunions with evidence of AVN
To take the online test and receive CME credit, go to http://www.assh.org/professionals/jhs.
JHS 䉬 Vol A, April
In Brief
Role of Vascularized Bone Grafts in the Treatment of Scaphoid Nonunions Associated With Proximal Pole Avascular Necrosis and Carpal Collapse
Role of Vascularized Bone Grafts in the Treatment of Scaphoid Nonunions Associated With Proximal Pole Avascular Necrosis and Carpal Collapse Sanjeev Kakar, MD, Allen T. Bishop, MD, Alexander Y. Shin, MD scaphoid nonunion has been estimated to be approximately 15%1 and can be related to a delay in diagnosis and treatment, proximal location of the fracture, displacement greater than 1 mm, and carpal instability.2– 4 Left untreated, these wrists often undergo progressive, predictable degenerative changes also known as scaphoid nonunion advanced collapse.5,6 Avascular necrosis (AVN) of the scaphoid occurs in an estimated 3% of all scaphoid fractures.7 Predominantly seen within the proximal pole, the etiology has been attributed to the retrograde intraosseous blood supply of the scaphoid. Plain radiographic signs of AVN include sclerosis of the proximal pole with occasional fragmentation and collapse. Computed tomography scans can effectively demonstrate collapse and bony characteristics of the nonunion, including resorptive findings, sclerosis, narrowing of joint spaces, and fragmentation.8 Magnetic resonance imaging (MRI) has been recommended to assess the vascularity of the proximal pole. Standard MRI has been shown to have an accuracy of 68%, which increases to 83% when gadolinium-enhanced MRI is used.9 Despite this, many surgeons rely solely on this modality, which only measures edema within the bone, not the actual blood flow. Currently, the only definitive method to determine vascularity of the proximal pole is direct intraoperative assessment to determine absence or presence of punctate bleeding of the proximal fragment, as was described by Green in 1985.10
T
HE INCIDENCE OF
In Brief
From the Department of Orthopaedic Surgery, Mayo Clinic, Rochester, MN. Received for publication October 15, 2010; accepted in revised form October 17, 2010. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Correspondingauthor:AlexanderY.Shin,MD,DepartmentofOrthopaedicSurgery,MayoClinic, 200 1st Street SW, Rochester, MN 55905; e-mail: [email protected]. 0363-5023/11/36A04-0031$36.00/0 doi:10.1016/j.jhsa.2010.10.015
722 䉬 © ASSH 䉬 Published by Elsevier, Inc. All rights reserved.
USE OF VASCULARIZED BONE GRAFTS IN THE TREATMENT OF SCAPHOID NONUNIONS Numerous techniques have been devised in the treatment of scaphoid nonunion with AVN of the proximal pole, such as the use of nonvascularized autografts including but not limited to anterior iliac crest and distal radius corticocancellous grafts.11,12 With a reported success rate of only 40% to 67%,13,14 these grafts have been less favored than pedicled vascularized bone grafts (VBGs), which have a union rate between 88% and 91%.2,15 With greater than 90% of the osteocytes surviving the transplantation procedure, graft-host union or revascularization occurs much more rapidly without substantial bone resorption or creeping substitution of necrotic bone that is seen with nonvascularized grafts.16 Based on the 1,2-intercompartmental supraretinacular artery (ICSRA), pedicled VBGs from the distal radius have been successfully used in the treatment of scaphoid nonunions. Zaidemberg et al.17 reported on the use of the ascending irrigating branch of the radial artery, which was essentially the 1,2-ICSRA vessel. They reported a 100% union rate in 11 chronic scaphoid nonunions at an average of 6 weeks, with improvements in rest pain and grip strength in all patients. Steinmann and colleagues18 treated 14 patients with the 1,2ICSRA and noted that all patients healed at an average of 11 weeks and 9 had good to excellent results. Patients with early arthritic changes were noted to have poorer outcomes than those without evidence of degeneration. Waitayawinyu et al.19 reported on 30 patients with established scaphoid nonunion, proximal pole AVN, and no previous surgery, who were treated with open reduction and internal fixation of the fracture and 1,2-ICSRA VBGs. Time to union was on average 5.1 months, with a success rate of 93%. Patients were found to have improved grip strength, satisfaction scores, and scaphoid height to length ratios, and 93% returned to preinjury work or sports activity. Sim-
723
compared with a 12 of 12 union rate after 13 weeks in ilar favorable results were reported by Tsai and 20 21 patients treated with an MFC graft (p ⬍ .001). colleagues and Waters and Stewart. Despite The MFC graft offers several advantages in the setthese promising studies, others have reported less ting of combined AVN and scaphoid humpback deforthan favorable results. In treating patients with proximal mity. The vascularity is robust and consistent, facilitatpole nonunions with AVN, Boyer et al.22 noted union ing harvest and microvascular anastomosis.24,25 Large in only 60% of patients. Similarly disappointing results 23 grafts can easily be obtained from the medial femoral were reported by Straw et al., with only 2 of 16 nonunions with AVN of the condyle and can be manipuEDUCATIONAL OBJECTIVES proximal pole united with lated to fit the defect with the 1,2-ICSRA VBGs. In a ● Discuss the diagnosis of methods to determine the vascularity of the prox- less risk of possible torsion imal scaphoid pole. critical review of results or damage to the vascular from a single institution, ● Describe the 1,2-intercompartmental supraretinacular artery (ICSRA) vas- pedicle. In addition, the cularized bone graft. Chang et al.13 determined quality of the cancellous that successful outcome us- ● State the advantages and disadvantages of the ICSRA for the treatment of bone quality is excellent ing the 1,2-ICSRA was not and provides greater strucproximal scaphoid pole avascular necrosis. universal and depended on ● Summarize the results of the ICSRA in the treatment of proximal scaphoid tural rigidity compared with careful patient selection and grafts harvested from the pole avascular necrosis. fracture selection. A total of ● Discuss the location and anatomy of the medial femoral condyle vascular distal radius. This tech48 patients with scaphoid nique is demanding and rebone graft for proximal scaphoid pole avascular necrosis. nonunions and/or osteone- ● Compare and contrast the ICSRA versus the medial femoral condyle vas- quires exceptional attention crosis were observed for an to detail in the insetting and cular bone graft for proximal scaphoid pole avascular necrosis. average of 7.8 months after fixation of the graft as well fracture fixation and 1,2- Earn up to 2 hours of CME credit per JHS issue when you read the related as the microsurgical anastoICSRA VBG. Union oc- articles and take the online test. To pay the $20 fee and take this month’s moses of the vessels to the curred in 71% of patients test, visit http://www.assh.org/professionals/jhs. radial artery and venae cowith scaphoid nonunion and mitantes. in 50% with AVN. Of the 14 failures, 9 were in patients with humpback deformity of the scaphoid and dorsal USE OF MEDIAL FEMORAL CONDYLE GRAFTS intercalated segment instability. In these patients, thereIN THE TREATMENT OF SCAPHOID NONUNIONS fore, restoration of normal scaphoid geometry with a Indications vascularized structural graft may need to be performed The primary indication for the use of the MFC is in the to enhance union and permit normal carpal kinematics. 12 correction of scaphoid nonunions associated with both As emphasized by Fisk nearly 30 years ago, reshumpback deformity of the scaphoid and AVN of the toration of carpal geometry was essential in obtaining proximal pole. The former is defined as a lateral intraunion of scaphoid nonunions associated with carpal scaphoid angle of 45° or greater (normal ⱕ35°). It is collapse. In our experience, however, we found that the often associated with dorsal intercalated segment instavascularized grafts obtained from the 1,2-ICSRA are bility deformity of the lunate, defined as a revised carpal limited in terms of the size and length of the pedicle to height ratio of 1.52 or less (normal ⫽ 1.57 ⫾ 0.05) or sufficiently correct the humpback deformity. A free radiolunate angle of 15° or greater (normal ⱕ10°). VBG that could provide a large VBG with a long Avascular necrosis can be detected by evidence of vascular pedicle was sought. The medial femoral consclerotic changes and/or cyst formation of the proximal dyle VBG, which was previously used as a corticopepole on radiographs or computed tomography scans. riosteal graft, was modified based on anatomic studMagnetic resonance imaging may be helpful in trying to ies24 –26 and a surgical technique was developed to elucidate diminished flow within the proximal pole of apply this VBG to scaphoid nonunions with AVN and 27 the scaphoid as evidenced by low signal intensity on carpal collapse. The results of this medial femoral both T1 and T2, and diminished uptake of contrast with condyle (MFC) VBG was reported by Jones et al.,28 gadolinium-enhanced MRI. 9 In our experience, howwho compared the outcomes of patients with scaphoid ever, we have found MRI to be unpredictable in assesswaist nonunions with AVN of the proximal pole with ing blood flow within the scaphoid, particularly in the carpal collapse treated with either a 1,2-ICSRA or MFC previous surgical scaphoid nonunion, and always conVBG. In patients treated with the 1,2-ICSRA grafts, 4 of 10 fractures healed at a median time of 19 weeks firm avascularity intraoperatively by the appearance of JHS 䉬 Vol A, April
In Brief
VASCULARIZED BONE GRAFT FOR SCAPHOID NONUNION
724
VASCULARIZED BONE GRAFT FOR SCAPHOID NONUNION
white sclerotic bone with absent punctate bleeding on tourniquet release as recommended by Green.10
In Brief
Contraindications Nondisplaced or minimally displaced scaphoid nonunions with AVN of the proximal pole but without humpback deformity are treated with an inlay VBG such as those based on the 1,2-ICSRA, the volar radius blood supply, or free iliac crest VBG.29 –31 In cases in which there is scaphoid humpback deformity without AVN, we advocate the use of nonvascularized wedge grafts such as the iliac crest and open reduction and internal fixation of the fracture.32 When there is evidence of radioscaphoid arthritic changes or advanced scaphoid nonunion, advanced collapse degenerative joint disease, consideration of salvage procedures including wrist denervation, scaphoid excision and 4-corner fusion, proximal row carpectomy, or complete wrist fusion must be made. Scaphoid nonunions complicated with humpback deformity and AVN of the proximal pole remain a challenging clinical scenario. This subset of patients has frequently been grouped together with those without AVN or collapse, making comparison of treatment outcomes difficult or impossible. However, careful analysis has demonstrated that failure to address both the structural and vascular deficiencies yields disappointing outcomes.2,13,28 A majority of pedicled VBGs from the distal radius have been described as inlay grafts. When pedicled VBGs from the distal radius are used as an interposition VBG to correct carpal malalignment, these grafts often fail to adequately restore scaphoid foreshortening resulting from the limited amount of bone that can be harvested as well as the quality of the bone, which leads to poor results. In contrast, free medial femoral condyle VBGs can provide not only structural support, but also a consistent and robust blood supply that results in excellent rates of union with restoration of scaphoid geometry and restoration of function.28 From our experience, the MFC graft provides both a robust and consistent vascular supply and optimal density of mostly cancellous bone from which large grafts (up to 1.5 cm3) can be harvested and shaped to fit the scaphoid defect with minimal donor site morbidity, and should be considered in the unique setting of a scaphoid nonunion with proximal pole AVN and carpal collapse. REFERENCES 1. Kuschner SH, Lane CS, Brien WW, Gellman H. Scaphoid fractures and scaphoid nonunion. Diagnosis and treatment. Orthop Rev 1994; 23:861– 871. 2. Merrell GA, Wolfe SW, Slade JF III. Treatment of scaphoid nonunions: quantitative meta-analysis of the literature. J Hand Surg 2002;27A:685– 691.
3. Pao VS, Chang J. Scaphoid nonunion: diagnosis and treatment. Plast Reconstr Surg 2003;112:1666 –1676, quiz 1677, discussion 1678 – 1679. 4. Trumble TE, Salas P, Barthel T, Robert KQ III. Management of scaphoid nonunions. J Am Acad Orthop Surg 2003;11:380 –391. 5. Mack GR, Bosse MJ, Gelberman RH, Yu E. The natural history of scaphoid nonunion. J Bone Joint Surg 1984;66A:504 –509. 6. Ruby LK, Stinson J, Belsky MR. The natural history of scaphoid nonunion. J Bone Joint Surg 1985;67A:428 – 432. 7. Eisenhauer MA. In: Marx JA, Hockenberger HS, Walls RM, eds. Rosen’s emergency medicine: concepts and clinical practice. 5th ed. St Louis, MO: Mosby, 2002:536 –555. 8. Smith ML, Bain GI, Chabrel N, Turner P, Carter C, Field J. Using computer tomography to assist with diagnosis of avascular necrosis complicating chronic scaphoid nonunion. J Hand Surg 2009;34A: 1037–1043. 9. Cerezal L, Abascal F, Canga A, Garcia-Valtuille R, Bustamante M, del Pinal F. Usefulness of gadolinium enhanced MR imaging in the evaluation of the vascularity of scaphoid nonunions. AJR Am J Roentgenol 2000;174:141–149. 10. Green DP. The effect of avascular necrosis on Russe bone grafting for scaphoid nonunion. J Hand Surg 1985;10A:597– 605. 11. Fernandez DL. Anterior bone grafting and conventional lag screw fixation to treat scaphoid nonunions. J Hand Surg 1990;15A:140 –147. 12. Fisk GR. Carpal instability and the fractured scaphoid. Ann R Coll Surg Engl 1970;46:63–76. 13. 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 2006;31A:387–396. 14. Krimmer H. Management of acute fractures and nonunions of the proximal pole of the scaphoid. J Hand Surg 2002;27B:245–248. 15. Munk B, Larsen CF. Bone grafting the scaphoid nonunion. A systematic review of 147 publications including 5246 cases of scaphoid nonunion. Acta Orthop Scand 2004;75:618 – 629. 16. Goldberg VM, Shaffer JW, Field G, Davy DT. Biology of vascularized bone grafts. Orthop Clin North Am 1987;18:179 –185. 17. Zaidemberg C, Siebert JW, Angrigiani C. A new vascularized bone graft for scaphoid nonunion. J Hand Surg 1991;16A:474 – 478. 18. Steinmann SP, Bishop AT, Berger RA. Use of the 1,2 intercompartmental supraretinacular artery as a vascularized pedicle bone graft for difficult scaphoid nonunion. J Hand Surg 2002;27A:391– 401. 19. Waitayawinyu T, McCallister WV, Katolik LI, Schlenker JD, Trumble TE. Outcome after vascularized bone grafting of scaphoid nonunions with avascular necrosis. J Hand Surg 2009;34A:387–394. 20. Tsai TT, Chao EK, Tu YK, Chen AC, Lee MS, Ueng SW. Management of scaphoid nonunion with avascular necrosis using 1,2 intercompartmental supraretinacular arterial bone grafts. Chang Gung Med J 2002;25:321–328. 21. Waters PM, Stewart SL. Surgical treatment of nonunion and avascular necrosis of the proximal part of the scaphoid in adolescents. J Bone J Surg 2002;84A:915–920. 22. Boyer MI, von Schroeder HP, Axelrod TS. Scaphoid nonunion with avascular necrosis of the proximal pole. Treatment with a vascularized bone graft from the dorsum of the distal radius. J Hand Surg 1998;23B:686 – 690. 23. Straw RG, Davis TR, Dias JJ. Scaphoid nonunion: treatment with a pedicled vascularized bone graft based on the 1,2 intercompartmental supraretinacular branch of the radial artery. J Hand Surg 2002; 27B:413– 416. 24. Doi K, Sakai K. Vascularized periosteal bone graft from the supracondylar region of the femur. Microsurgery 1994;15:305–315. 25. Sakai K, Doi K, Kawai S. Free vascularized thin corticoperiosteal graft. Plast Reconstr Surg 1991;87:290 –298. 26. Yamamoto H, Jones DB Jr, Moran SL, Bishop AT, Shin AY. The arterial anatomy of the medial femoral condyle and its clinical implications. J Hand Surg 2010;l35B:569 –574. 27. Larson AN, Bishop AT, Shin AY. Free medial femoral condyle bone
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grafting for scaphoid nonunions with humpback deformity and proximal pole avascular necrosis. Tech Hand Upper Extrem Surg 2007;11:246–258. 28. Jones DB Jr, Burger H, Bishop AT, Shin AY. Treatment of scaphoid waist nonunions with an avascular proximal pole and carpal collapse. A comparison of two vascularized bone grafts. J Bone Joint Surg 2008;90A:2616 –2625. 29. Mathoulin C, Haerle M. Vascularized bone graft from the palmar carpal artery for treatment of scaphoid nonunion. J Hand Surg 1998;23B:318 –323.
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30. Mathoulin C, Haerle M, Vandeputte G. Vascularized bone graft in carpal bone reconstruction. Ann Chir Plast Esthet 2005;50: 43– 48. 31. Harpf C, Gabl M, Reinhart C. Small free vascularized iliac crest bone grafts in reconstruction of the scaphoid bone: a retrospective study in 60 cases. Plast Reconstr Surg 2001;108:664 – 674. 32. Fernandez DL, Eggli S. Nonunion of the scaphoid. Revascularization of the proximal pole with implantation of a vascular bundle and bone grafting. J Bone J Surg 1995;6:883– 893.
JOURNAL CME QUESTIONS
What is the definitive method to determine vascularity of the proximal scaphoid pole? a. Magnetic resonance imaging (MRI) b. Gadolinium-enhanced MRI c. Computerized tomography d. Intraoperative assessment e. Bone scan
What is the primary indication for the use of medial femoral condyle vascular bone graft in the correction of scaphoid nonunions? a. Scaphoid nonunions with a humpback deformity of the scaphoid and with avascular necrosis (AVN) of the proximal pole b. Scaphoid nonunions without a humpback deformity of the scaphoid and with AVN of the proximal pole trunk c. Scaphoid nonunions without a humpback deformity of the scaphoid and without AVN of the proximal pole trunk d. Scaphoid nonunions with a humpback deformity of the scaphoid and without AVN of the proximal pole trunk e. All scaphoid nonunions with evidence of AVN
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JHS 䉬 Vol A, April
In Brief
Role of Vascularized Bone Grafts in the Treatment of Scaphoid Nonunions Associated With Proximal Pole Avascular Necrosis and Carpal Collapse