- Email: [email protected]
Skeletal Reconstruction by Vascularized Bone Transfer: Indications and Results
cfe? Proceedings Vol. 60
ROCHESTER, MINNESOTA
NOVEMBER 1985
Skeletal Reconstruction by Vascularized Bone Transfer: Indications and Results
MICHAEL B. W O O D , M . D . , WILLIAM P. COONEY III, M . D . Department of Orthopedics; GEORGE B. IRONS, Jr., M.D., Section of Plastic and Reconstructive Surgery
The indications for and the results of 60 consecutive microvascular bone transfers performed at our institution during a 50-month period are reviewed. All 60 patients were followed up for at least 1 year. The overall primary union rate was 67%, and the eventual union rate was 77%. The most frequent indication for the procedure was long-bone reconstruction after limb-salvage wide local resection of a malignant tumor. We achieved the best results with limb reconstruction after resection of a malignant tumor and with recipient sites that involved the forearm or mandible. In contrast, our results were least favorable with reconstruction after resection for chronic osteomyelitis and with reconstruction of defects of the shoulder girdle. Overall, vascularized bone transfer seems to be a valuable reconstructive technique for management of clinical problems that involve massive skeletal defects. Because of continued refinement and application of mi crovascular techniques, free transfer of various types of tissue and immediate revascularization by anastomosis of the pedicle vessels at the recipient site are possible. In addition to skin flaps, muscles, omentum, and digits, vascularized bone segments may be used in this manner for reconstruction of extensive skeletal defects. During the past 10 years, use of the technique of free vascular ized bone transfer for numerous difficult problems has increased. The clinical applications for this procedure include skeletal reconstruction of defects that result from congenital anomalies, 1,2 resection of tumors, 3 " 5 deep infection, 6,7 and traumatic bone loss. 2 , 4 , 6 , 8 " 1 0 Recently, the value of this procedure has even been highlighted, albeit with some embellishment, in the lay press and news media. 11 Despite this attention, however, relatively few scientific reports have addressed the indications, Address reprint requests to Dr. M. B. Wood, Department of Orthope dics, Mayo Clinic, Rochester, MN 55905. Mayo Clin Proc 60:729-734, 1985
limitations, complications, and results of vascularized bone transfers in a large series of patients. Since 1980, more than 90 such procedures have been performed at our institution. Herein we review our experience with 60 patients who underwent this procedure and who have been followed up for a minimum of 1 year. METHODS The records of all patients who underwent a microvascu lar bone transfer for reconstruction of a bony defect during a 50-month period between 1980 and 1984 and who had at least 1 year of follow-up were reviewed. All the procedures were performed by the authors. The indications for the procedures and the results in terms of bone union were emphasized. Unequivocal x-ray evi dence of bone healing at both ends of the graft was required to declare the bone segment united. All major complications and required secondary treatment were recorded. The results were analyzed in relationship to the indication for the procedure, the selection of donor bone, 729
730
VASCULARIZED BONE TRANSFER
the recipient bone site, and the patency of the vascular anastomoses. INDICATIONS In general, we have limited the application of vascularized bone transfer to clinical situations involving a bony defect that is unlikely to heal with use of standard bonegrafting techniques. In this series, the length of bony defect that necessitated reconstruction ranged from 5 to 24 cm. For defects less than 8 cm, reconstruction by vascularized bone transfer was selected only for those patients with lack of healing after an apparently wellexecuted conventional bone-grafting procedure or for those patients with poorly vascularized soft tissues as a result of irradiation, chronic sepsis, or multiple prior operative procedures. Most of the patients with shorter defects underwent compound osteocutaneous flap trans fer because they required soft tissue augmentation in addition to bone reconstruction. Generally, however, in patients in whom the bony defect was less than 8 cm and soft tissue reconstruction did not necessitate a free microvascular tissue transfer, management involved a simpler means of soft tissue replacement followed by a conven tional bone-grafting procedure. The figure of 8 cm was arbitrarily chosen as the length beyond which vascular ized bone transfer was elected over a conventional bone graft. Other authors 2,4 " 6 have suggested 6 cm as the critical length of defect beyond which a vascularized bone segment should be considered. We acknowledge that in some patients, particularly those with well-vascularized soft tissue, defects in excess of 8 cm can be managed by conventional bone-grafting techniques. In the current series, vascularized bone transfer was indicated most commonly in patients who were undergo ing limb-salvage procedures for malignant or locally aggressive bone tumors, in those who were undergoing radical debridement for chronic osteomyelitis, and in patients with acute or subacute traumatic bone loss from penetrating injuries. CONTRAINDICATIONS We believe that a vascularized bone transfer procedure has three general contraindications: (1) the availability of simpler, reliable methods for bone reconstruction, (2) limbs with poor functional potential that may be better served by amputation, and (3) the lack of appropriate vessels for microvascular anastomoses. In most instances in this series, assessment of the vascular anatomy of the recipient site was based on clinical and Doppler exami nations. Fewer than a third of our patients underwent preoperativearteriography. In general, if the major vessel that supplied the recipient limb had palpable pulses at or
Mayo Clin Proc, November 1985, Vol 60
distal to the level of the injury, arteriography was not performed. Only in those patients in whom palpable or Doppler-audible pulses were not present and, in particu lar, in those patients with suspected vascular disease or prior vascular injury was a preoperative arteriogram obtained. DONOR BONE SITES Although various donor bone sites have been de scribed, 1 , 2 ' 4 ' 8 ' Ί 0 ' 1 2 " 1 6 for practical purposes only two choices are available: fibula (with the peroneal artery and accompanying veins [Fig. 1 ]) or anterior iliac crest (with the deep circumflex iliac artery and veins). The selection between these two sites is usually based on several factors, including the shape of the recipient bone defect, the coexistent need for soft tissue to accompany the bone, and the expendability of either the iliac crest or the fibula in a specific patient. In general, lengthy diaphyseal defects that require cortical bone structural stability with out a voluminous loss of soft tissue are best suited to reconstruction by transfer of a segment of the fibula. Conversely, for shorter gaps or conditions that necessi tate osteotomy and extensive sculpturing of the bone in association with substantial loss of soft tissue at the recipient site, the usual selection should be the iliac crest or an iliac crest-groin skin compound flap. RESULTS The range of follow-up of the 60 patients in this study was 12 to 62 months (mean, 29.7 months). Of the 60 patients, 40 (67%) had primary union of the bone graft. In addi tion, six patients had union of the graft after further surgical intervention that involved internal fixation and a conventional cancellous bone-grafting procedure. Therefore, the overall eventual rate of union was 77%. Of the remaining 14 patients, 6 are still undergoing treat ment directed at obtaining union, 4 have undergone limb amputation, 2 are insufficiently symptomatic to warrant further operative treatment, 1 has undergone multistaged conventional reconstruction, and 1 has died. Related to Diagnosis.—The most frequent indication for vascularized bone segment transfer (23 patients) was reconstruction of an extensive long-bone defect necessi tated by resection of a primary bone tumor (Table 1). Most of these lesions were relatively low-grade malignant tumors, and the procedure recommended was radical resection and limb salvage. In a third of our patients, the indication was reconstruction of a bony defect that result ed from sequestrectomy and bone resection for chronic osteomyelitis. Many of the patients in this group had a coexistent substantial soft tissue defect that necessitated the use of a compound flap of iliac crest and groin skin.
Mayo Clin Proc, November 1985, Vol 60
VASCULARIZED BONE TRANSFER
731
whom limb amputation was under consideration as the alternative means of management. Of the 20 patients who had osteomyelitis, 15 underwent reconstruction by vascularized bone transfer as a delayed primary proce dure within 10 days after the initial debridement. The other five patients in this group underwent reconstruction after the soft tissues had healed; this secondary procedure was done 2V2 to ό'Λ months after the initial debridement. The indication for vascularized bone transfer in the re maining 17 patients was reconstruction of a traumatic long-bone defect. In most patients, the defect was due to an open fracture that had resulted from a farm implement or vehicular accident or from a penetrating injury (such as a gunshot wound). The patients who underwent bone transfer because of a defect caused by a tumor had the best results in terms of bone healing; 20 of the 23 patients (87%) had uneventful primary union. Two procedures in this group of patients were frank failures, and one patient is still undergoing treatment for nonunion. In contrast, the results were least favorable in those patients who underwent reconstruc tion for osteomyelitis. Primary bone union occurred in 8 of the 20 patients (40%), and 4 additional patients had healing after further surgical intervention. Therefore, eventual bone union was achieved in 60% of the patients in this group. Of the eight patients with chronic osteo myelitis in whom bone union was not achieved, four are still undergoing treatment in an effort to gain union, and four have undergone limb amputation. At last follow-up, three patients in the osteomyelitis group had a recurrence of deep bony sepsis at some stage after vascularized bone transfer; two of these patients ultimately required ampu tation. The remaining patient has apparently been free of sepsis, and union of the graft occurred after sequestrectomy. Two of the patients with recurrent sepsis were in the group that underwent delayed primary reconstruc tion, and the third patient had been managed by second ary reconstruction. Fig. 1. Diagram of ipsilateral free transfer of fibular segment to femoral defect. Revascularization is accomplished by end-to-side anastomosis of peroneal artery to superficial femoral artery and end-to-end anasto mosis of one peroneal vena comitans to saphenous vein, a = artery; v = vein
All patients in the group with osteomyelitis had extensive osteomedullary involvement with sequestra, sclerosis of bone, actively draining sinus tracts, and positive bacteriologic cultures. In all of them, an ununited fracture was present. Most such patients had undergone multiple prior attempts at debridement of infected bone and manage ment of wounds by a variety of methods. In general, radical resection and reconstruction by vascularized bone transfer were recommended for those patients in
The patients who underwent vascularized bone trans fer for reconstruction of traumatic defects had intermedi ate results. Of the 17 patients, 12 (71%) had primary bone union, and 2 additional patients (12%) had union after internal fixation and cancellous bone grafting. Therefore, eventual bone union was achieved in 82% of this group. Of the three patients who did not have bone union in this group, one is still undergoing treatment, and two have received alternative treatment. Related to Recipient Site.—The two most frequent recipient sites for vascularized bone transfer in our study were the tibia (23 patients) and the femur (16 patients) (Table 2). The results in terms of bone union were strik ingly similar for both of these sites. Primary bone healing
732
Mayo Clin Proc, November 1985, Vol 60
VASCULARIZED BONE TRANSFER
Table 1 .--Indications for Vascularized Bone Transfer and Related Results Result Indication
No. of patients
Primary union
Union after second operation
Tumor Osteomyelitis Traumatic loss of bone
23 20 17
20 8 12
0 4 2
Nonunion*
Failuret
1 7 1
2 1 2
'Patients are still undergoing treatment to achieve union, have minimal symptoms that do not necessitate further surgical intervention, or have undergone late amputation. tEarly amputation or alternative treatment undertaken.
occurred in 13 of the tibial reconstructions (57%) and in 10 of the femoral reconstructions (62%). After a second ary operation, bone union was obtained in four addition al patients who had tibial defects and two additional patients who had femoral defects. Therefore, eventual union was achieved in 74% and 75% of patients who underwent tibial and femoral reconstruction, respective ly. Three patients with tibial nonunions and two with femoral nonunions are still undergoing treatment. The remaining patients with nonunions in both groups have either undergone amputation or received alternative treatment. Primary union occurred in all patients who underwent vascularized bone transfer for reconstruction of the radi us or mandible but in only four of five patients with pelvic defects, three of five with humeral defects, and one of two with clavicular defects. The two patients with non union after humeral reconstructions are still undergoing treatment to achieve bone union. The patient with failure of union in the pelvis died of metastatic disease. Because the patient with the persistent clavicular nonunion was only minimally symptomatic, further treatment efforts were abandoned. Related to Donor Site.—The fibula was selected for transfer in almost two thirds of the procedures in this series (39 patients) (Table 3). Four of the fibular transfers were compound osteocutaneous flaps. The iliac crest was the donor site in 20 patients. In one patient with a
flail upper extremity, a forearm osteocutaneous flap was successfully used for reconstruction of the femur. 17 Of the 39 patients who had fibular transfers, 28 (72%) had primary bone union. Two other patients had union after a further operation. Thus, the overall eventual union rate was 77%. Of the remaining nine patients with a fibulartransferthatfailedtoheal, four are still undergoing treatment, three have undergone amputation, and two are insufficiently symptomatic to warrant further surgical intervention. Of the 20 patients who had iliac crest transfers, 11 (55%) had primary union and 4 had union after a further surgical procedure. Therefore, 75% of patients in this group eventually had bone union. Of the five patients with an iliac crest transfer that has not healed, two are still undergoing treatment, one received alternative treat ment, one has undergone amputation, and one has died. Related to Vascular Anastomosis.~An accurate as sessment of patency of the vascular anastomoses during the postoperative period was not possible for all patients in this series. In no instance was arteriography used for this purpose. In 23 patients, an osteocutaneous com pound flap was used for the vascularized bone transfer. In these patients, accurate visual assessment of the vascular patency in the inclusive skin flap was possible. In this group, union was not attained in five patients, and the failure was related to vascular thrombosis in two of them. In another 23 patients, "Tc-diphosphonate bone scan-
Table 2.—Recipient Sites for Vascularized Bone Transfer and Related Results Result Recipient site
No. of patients
Primary union
Union after second operation
Tibia Femur Radius Pelvis Humerus Mandible Clavicle
23 16 5 5 5 4 2
13 10 5 4 3 4 1
4 2 0 0 0 0 0
Nonunion*
Failuret
4 3 0 0 2 0 0
2 1 0 1 0 0 1
•Patients are still undergoing treatment to achieve union, have minimal symptoms that do not necessitate further surgical intervention, or have undergone late amputation. tEarly amputation or alternative treatment undertaken.
VASCULARIZED BONE TRANSFER
Mayo Clin Proc, November 1985, Vol 60
733
Table 3,—Donor Sites for Vascularized Bone Transfer and Related Results Result Donor site Fibula Iliac crest Other (radius/ulna)
No. of patients
Primary union
Union after second operation
39* 20 1
28 11 1
2 4 0
Nonunion*
Failuret
6 3 0
3 2 0
•Patients are still undergoing treatment to achieve union, have minimal symptoms that do not necessitate further surgical intervention, or have undergone late amputation. tEarly amputation or alternative treatment undertaken. ΦΙη four patients, the fibular transfers were compound osteocutaneous flaps.
ning was used for assessment during the first postopera tive week. Of this group, 16 patients had positive scintil lation activity over the transferred bone segment, and all but 3 of these patients eventually had bone union. Of the seven patients with negative or equivocal scans, four had bone union. In addition, one patient underwent postop erative reexploration that confirmed vascular patency, and a satisfactory union was eventually achieved. In the remaining 13 patients, no assessment of the vascular anastomosis was possible; 10 of these patients eventually had bone union. COMPLICATIONS In addition to the aforementioned complications that related to failure, delayed union, nonunion, and recur rent sepsis, seven patients (12%) had complications re lated to the donor site. Three patients suffered a peroneal palsy after harvest of a fibula. In all three patients, the paralysis was transient and neurologic recovery was complete. One patient who underwent fibular transfer sustained an apparent stress fracture with displacement of the ipsilateral tibia 6 months postoperatively. This patient had poorly controlled diabetes mellitus but no other apparent abnormalities or obvious trauma to the involved tibia. One additional patient who underwent fibular transfer in combination with humeral allografting for proximal humeral reconstruction had deep wound sepsis early postoperatively. This complication necessi tated removal of all prosthetic hardware and the allograft, but the fibula remained well vascularized and was re tained. She had a satisfactory outcome with no residual deep sepsis and an asymptomatic stable fibrous non union of a scapulohumeral arthrodesis. In two patients who underwent iliac crest transfer, a hernia developed at the donor site. Both patients were minimally sympto matic, and neither patient required secondary repair or reconstruction. DISCUSSION The purpose of this review was to determine objectively the results of microvascular free bone transfer at our
institution. We are unaware of any similar study with which we could compare our results. In our analysis, we were particularly interested in those factors and variables that favorably or unfavorably influenced the clinical outcome. Identification of such factors may help prompt formulation of the specific indications for this procedure or may suggest appropriate modifications of the surgical technique. Overall, our experience suggests that vascularized bone transfer can be expected to result in uneventful bone union in 67% of patients. The eventual union rate after various procedures such as secondary bone grafting, secondary internal fixation, or electrical stimulation techniques is about 77%. These figures are somewhat lower than the 73% primary union and the 88% eventual union reported by Weiland and associates6 in a slightly smaller series of patients. Our results were best with limb reconstruction after resection of a bone tumor (87% primary union rate), with reconstruction of forearm or mandibular defects (100% primary union rate), and with the selection of a fibular donor site (72% primary and 77% ultimate union rates). In contrast, our results were poorest with limb recon struction after radical bone debridement for chronic os teomyelitis (40% primary and 60% ultimate union rates), with reconstruction of defects of the shoulder region (57% primary union rate for humerus and clavicle com bined), and with the selection of an iliac crest donor site (55% primary and 75% ultimate union rates). Recon struction of traumatic defects or those that involved the tibia, femur, or pelvis yielded intermediate results. We believe that the explanation for the differing results relates to the stability of the transferred bone, the use of additional bone-grafting material, and the adequacy of postoperative support and immobilization. In general, patients who underwent reconstruction after excision of a bone tumor had extremely stable internal fixation with plates or intramedullary nails, which was augmented with a conventional bone graft. In contrast, those patients who underwent reconstruction for osteomyelitis were managed with external fixation and minimal internal
734
VASCULARIZED BONE TRANSFER
Mayo Clin Proc, November 1985, Vol 60
hardware without supplementation by nonvascularized bone-grafting material. The fibula, because of its strong linear cortical structure, was advantageous for fixation with screws and hardware as well as fixation by intramedullary insertion of the fibular segment into the recipi ent defect (Fig. 1). The forearm was easily supported postoperatively by a long-arm cast, but the humerus and clavicle defied secure external immobilization even with a shoulder spica cast. Complications other than delayed union or nonunion were relatively minimal. Transient peroneal palsy after harvest of a fibula occurred in 3 of 39 patients (8%), and an iliac hernia developed in 2 of 20 patients (10%) who underwent iliac crest transfer. No serious vascular com plications were noted in either of these groups. Only one deep infection occurred among the patients who under went reconstruction for factors other than osteomyelitis. In this series, we were unable to correlate strongly the incidence of clinical success with the presence or ab sence of patency of the vascular anastomoses. Of the 14 patients who did not have a satisfactory bone union, 6 were thought to have patent anastomoses on the basis of sustained viability of an accompanying cutaneous flap or a positive bone scan. Vascular thrombosis was suspected because of necrosis of an accompanying skin flap or a negative bone scan in five patients, and no assessment of patency was possible in three.
REFERENCES
CONCLUSIONS In our experience, skeletal reconstruction by vascular ized bone transfer has proved to be a valuable procedure for patients unlikely to heal with standard bone-grafting techniques. Eventual union rates of at least 75% can be achieved, and the incidence of related complications is acceptable. We suggest that this procedure yields partic ularly good results in patients who are undergoing recon struction of the radius or mandible and in patients who are undergoing limb-salvage bone resection for a malig nant tumor.
15.
1. 2.
3. 4.
5.
6. 7.
8.
9.
10.
11. 12.
13. 14.
16.
17.
Gilbert A: Surgical technique: vascularized transfer of the fibular shaft. Int J Microsurg 1:100-102, 1979 Weiland A), Daniel RK: Microvascular anastomoses for bone grafts in the treatment of massive defects in bone. J Bone Joint Surg [Am] 61:98-104, 1979 P h o R W H : Free vascularised fibular transplant for replacement of the lower radius. J Bone Joint Surg |Br[ 61:362-365, 1979 Wood MB, Cooney WP III, Irons GB: Posttraumatic lower extrem ity reconstruction by vascularized bone graft transfer. Orthope dics 7:255-262, 1984 Weiland AJ, Kleinen HE, Kutz JE, Daniel RK: Free vascularized bone grafts in surgery of the upper extremity. J Hand Surg 4:129-144, 1979 Weiland AJ, Moore JR, Daniel RK: Vascularized bone autografts: experience with 41 cases. Clin Orthop 174:87-95, 1983 Wood MB, Cooney WP III: Vascularized bone segment transfers for management of chronic osteomyelitis. Orthop Clin North Am 15:461-472, 1984 Buncke HJ, Furnas D W , Gordon L, Achauer BM: Free osteocutaneous flap from a rib to the tibia. Plast Reconstr Surg 59:799-805, 1977 Taylor G l , Townsend P, Corlett R: Superiority of the deep circum flex iliac vessels as the supply for free groin flaps: clinical work. Plast Reconstr Surg 64:745-759, 1979 Biemer E, Stock W : Total thumb reconstruction: a one-stage reconstruction using an osteo-cutaneous forearm flap. Br J Plast Surg 36:52-55, 1983 Time Magazine: Medicine. January 14, 1985 TaylorGI, M i l l e r G D H , Ham FJ: The free vascularized bone graft: a clinical extension of microvascular techniques. Plast Reconstr Surg 55:533-544, 1975 Daniel RK: Free rib transfer by microvascular anastomoses (letter to the editor). Plast Reconstr Surg 59:737-738, 1977 Taylor Gl, Watson N: One-stage repair of compound leg defects with free, revascularized flaps of groin skin and iliac bone. Plast Reconstr Surg 61:494-506, 1978 TaylorGI, Townsend P, Corlett R: Superiority of the deep circum flex iliac vessels as the supply for free groin flaps: experimental work. Plast Reconstr Surg 64:595-604, 1979 Teot L, Bosse JP, Moufarrige R, Papillon J, Beauregard G: The scapula crest pedicled bone graft. Int J Microsurg 3:257-262, 1981 Mixter RC, W o o d M B : Closure of a defect of the femur with a compound free forearm transfer including both the radius and the ulna. Br J Plast Surg 36:470-472, 1983
ROCHESTER, MINNESOTA
NOVEMBER 1985
Skeletal Reconstruction by Vascularized Bone Transfer: Indications and Results
MICHAEL B. W O O D , M . D . , WILLIAM P. COONEY III, M . D . Department of Orthopedics; GEORGE B. IRONS, Jr., M.D., Section of Plastic and Reconstructive Surgery
The indications for and the results of 60 consecutive microvascular bone transfers performed at our institution during a 50-month period are reviewed. All 60 patients were followed up for at least 1 year. The overall primary union rate was 67%, and the eventual union rate was 77%. The most frequent indication for the procedure was long-bone reconstruction after limb-salvage wide local resection of a malignant tumor. We achieved the best results with limb reconstruction after resection of a malignant tumor and with recipient sites that involved the forearm or mandible. In contrast, our results were least favorable with reconstruction after resection for chronic osteomyelitis and with reconstruction of defects of the shoulder girdle. Overall, vascularized bone transfer seems to be a valuable reconstructive technique for management of clinical problems that involve massive skeletal defects. Because of continued refinement and application of mi crovascular techniques, free transfer of various types of tissue and immediate revascularization by anastomosis of the pedicle vessels at the recipient site are possible. In addition to skin flaps, muscles, omentum, and digits, vascularized bone segments may be used in this manner for reconstruction of extensive skeletal defects. During the past 10 years, use of the technique of free vascular ized bone transfer for numerous difficult problems has increased. The clinical applications for this procedure include skeletal reconstruction of defects that result from congenital anomalies, 1,2 resection of tumors, 3 " 5 deep infection, 6,7 and traumatic bone loss. 2 , 4 , 6 , 8 " 1 0 Recently, the value of this procedure has even been highlighted, albeit with some embellishment, in the lay press and news media. 11 Despite this attention, however, relatively few scientific reports have addressed the indications, Address reprint requests to Dr. M. B. Wood, Department of Orthope dics, Mayo Clinic, Rochester, MN 55905. Mayo Clin Proc 60:729-734, 1985
limitations, complications, and results of vascularized bone transfers in a large series of patients. Since 1980, more than 90 such procedures have been performed at our institution. Herein we review our experience with 60 patients who underwent this procedure and who have been followed up for a minimum of 1 year. METHODS The records of all patients who underwent a microvascu lar bone transfer for reconstruction of a bony defect during a 50-month period between 1980 and 1984 and who had at least 1 year of follow-up were reviewed. All the procedures were performed by the authors. The indications for the procedures and the results in terms of bone union were emphasized. Unequivocal x-ray evi dence of bone healing at both ends of the graft was required to declare the bone segment united. All major complications and required secondary treatment were recorded. The results were analyzed in relationship to the indication for the procedure, the selection of donor bone, 729
730
VASCULARIZED BONE TRANSFER
the recipient bone site, and the patency of the vascular anastomoses. INDICATIONS In general, we have limited the application of vascularized bone transfer to clinical situations involving a bony defect that is unlikely to heal with use of standard bonegrafting techniques. In this series, the length of bony defect that necessitated reconstruction ranged from 5 to 24 cm. For defects less than 8 cm, reconstruction by vascularized bone transfer was selected only for those patients with lack of healing after an apparently wellexecuted conventional bone-grafting procedure or for those patients with poorly vascularized soft tissues as a result of irradiation, chronic sepsis, or multiple prior operative procedures. Most of the patients with shorter defects underwent compound osteocutaneous flap trans fer because they required soft tissue augmentation in addition to bone reconstruction. Generally, however, in patients in whom the bony defect was less than 8 cm and soft tissue reconstruction did not necessitate a free microvascular tissue transfer, management involved a simpler means of soft tissue replacement followed by a conven tional bone-grafting procedure. The figure of 8 cm was arbitrarily chosen as the length beyond which vascular ized bone transfer was elected over a conventional bone graft. Other authors 2,4 " 6 have suggested 6 cm as the critical length of defect beyond which a vascularized bone segment should be considered. We acknowledge that in some patients, particularly those with well-vascularized soft tissue, defects in excess of 8 cm can be managed by conventional bone-grafting techniques. In the current series, vascularized bone transfer was indicated most commonly in patients who were undergo ing limb-salvage procedures for malignant or locally aggressive bone tumors, in those who were undergoing radical debridement for chronic osteomyelitis, and in patients with acute or subacute traumatic bone loss from penetrating injuries. CONTRAINDICATIONS We believe that a vascularized bone transfer procedure has three general contraindications: (1) the availability of simpler, reliable methods for bone reconstruction, (2) limbs with poor functional potential that may be better served by amputation, and (3) the lack of appropriate vessels for microvascular anastomoses. In most instances in this series, assessment of the vascular anatomy of the recipient site was based on clinical and Doppler exami nations. Fewer than a third of our patients underwent preoperativearteriography. In general, if the major vessel that supplied the recipient limb had palpable pulses at or
Mayo Clin Proc, November 1985, Vol 60
distal to the level of the injury, arteriography was not performed. Only in those patients in whom palpable or Doppler-audible pulses were not present and, in particu lar, in those patients with suspected vascular disease or prior vascular injury was a preoperative arteriogram obtained. DONOR BONE SITES Although various donor bone sites have been de scribed, 1 , 2 ' 4 ' 8 ' Ί 0 ' 1 2 " 1 6 for practical purposes only two choices are available: fibula (with the peroneal artery and accompanying veins [Fig. 1 ]) or anterior iliac crest (with the deep circumflex iliac artery and veins). The selection between these two sites is usually based on several factors, including the shape of the recipient bone defect, the coexistent need for soft tissue to accompany the bone, and the expendability of either the iliac crest or the fibula in a specific patient. In general, lengthy diaphyseal defects that require cortical bone structural stability with out a voluminous loss of soft tissue are best suited to reconstruction by transfer of a segment of the fibula. Conversely, for shorter gaps or conditions that necessi tate osteotomy and extensive sculpturing of the bone in association with substantial loss of soft tissue at the recipient site, the usual selection should be the iliac crest or an iliac crest-groin skin compound flap. RESULTS The range of follow-up of the 60 patients in this study was 12 to 62 months (mean, 29.7 months). Of the 60 patients, 40 (67%) had primary union of the bone graft. In addi tion, six patients had union of the graft after further surgical intervention that involved internal fixation and a conventional cancellous bone-grafting procedure. Therefore, the overall eventual rate of union was 77%. Of the remaining 14 patients, 6 are still undergoing treat ment directed at obtaining union, 4 have undergone limb amputation, 2 are insufficiently symptomatic to warrant further operative treatment, 1 has undergone multistaged conventional reconstruction, and 1 has died. Related to Diagnosis.—The most frequent indication for vascularized bone segment transfer (23 patients) was reconstruction of an extensive long-bone defect necessi tated by resection of a primary bone tumor (Table 1). Most of these lesions were relatively low-grade malignant tumors, and the procedure recommended was radical resection and limb salvage. In a third of our patients, the indication was reconstruction of a bony defect that result ed from sequestrectomy and bone resection for chronic osteomyelitis. Many of the patients in this group had a coexistent substantial soft tissue defect that necessitated the use of a compound flap of iliac crest and groin skin.
Mayo Clin Proc, November 1985, Vol 60
VASCULARIZED BONE TRANSFER
731
whom limb amputation was under consideration as the alternative means of management. Of the 20 patients who had osteomyelitis, 15 underwent reconstruction by vascularized bone transfer as a delayed primary proce dure within 10 days after the initial debridement. The other five patients in this group underwent reconstruction after the soft tissues had healed; this secondary procedure was done 2V2 to ό'Λ months after the initial debridement. The indication for vascularized bone transfer in the re maining 17 patients was reconstruction of a traumatic long-bone defect. In most patients, the defect was due to an open fracture that had resulted from a farm implement or vehicular accident or from a penetrating injury (such as a gunshot wound). The patients who underwent bone transfer because of a defect caused by a tumor had the best results in terms of bone healing; 20 of the 23 patients (87%) had uneventful primary union. Two procedures in this group of patients were frank failures, and one patient is still undergoing treatment for nonunion. In contrast, the results were least favorable in those patients who underwent reconstruc tion for osteomyelitis. Primary bone union occurred in 8 of the 20 patients (40%), and 4 additional patients had healing after further surgical intervention. Therefore, eventual bone union was achieved in 60% of the patients in this group. Of the eight patients with chronic osteo myelitis in whom bone union was not achieved, four are still undergoing treatment in an effort to gain union, and four have undergone limb amputation. At last follow-up, three patients in the osteomyelitis group had a recurrence of deep bony sepsis at some stage after vascularized bone transfer; two of these patients ultimately required ampu tation. The remaining patient has apparently been free of sepsis, and union of the graft occurred after sequestrectomy. Two of the patients with recurrent sepsis were in the group that underwent delayed primary reconstruc tion, and the third patient had been managed by second ary reconstruction. Fig. 1. Diagram of ipsilateral free transfer of fibular segment to femoral defect. Revascularization is accomplished by end-to-side anastomosis of peroneal artery to superficial femoral artery and end-to-end anasto mosis of one peroneal vena comitans to saphenous vein, a = artery; v = vein
All patients in the group with osteomyelitis had extensive osteomedullary involvement with sequestra, sclerosis of bone, actively draining sinus tracts, and positive bacteriologic cultures. In all of them, an ununited fracture was present. Most such patients had undergone multiple prior attempts at debridement of infected bone and manage ment of wounds by a variety of methods. In general, radical resection and reconstruction by vascularized bone transfer were recommended for those patients in
The patients who underwent vascularized bone trans fer for reconstruction of traumatic defects had intermedi ate results. Of the 17 patients, 12 (71%) had primary bone union, and 2 additional patients (12%) had union after internal fixation and cancellous bone grafting. Therefore, eventual bone union was achieved in 82% of this group. Of the three patients who did not have bone union in this group, one is still undergoing treatment, and two have received alternative treatment. Related to Recipient Site.—The two most frequent recipient sites for vascularized bone transfer in our study were the tibia (23 patients) and the femur (16 patients) (Table 2). The results in terms of bone union were strik ingly similar for both of these sites. Primary bone healing
732
Mayo Clin Proc, November 1985, Vol 60
VASCULARIZED BONE TRANSFER
Table 1 .--Indications for Vascularized Bone Transfer and Related Results Result Indication
No. of patients
Primary union
Union after second operation
Tumor Osteomyelitis Traumatic loss of bone
23 20 17
20 8 12
0 4 2
Nonunion*
Failuret
1 7 1
2 1 2
'Patients are still undergoing treatment to achieve union, have minimal symptoms that do not necessitate further surgical intervention, or have undergone late amputation. tEarly amputation or alternative treatment undertaken.
occurred in 13 of the tibial reconstructions (57%) and in 10 of the femoral reconstructions (62%). After a second ary operation, bone union was obtained in four addition al patients who had tibial defects and two additional patients who had femoral defects. Therefore, eventual union was achieved in 74% and 75% of patients who underwent tibial and femoral reconstruction, respective ly. Three patients with tibial nonunions and two with femoral nonunions are still undergoing treatment. The remaining patients with nonunions in both groups have either undergone amputation or received alternative treatment. Primary union occurred in all patients who underwent vascularized bone transfer for reconstruction of the radi us or mandible but in only four of five patients with pelvic defects, three of five with humeral defects, and one of two with clavicular defects. The two patients with non union after humeral reconstructions are still undergoing treatment to achieve bone union. The patient with failure of union in the pelvis died of metastatic disease. Because the patient with the persistent clavicular nonunion was only minimally symptomatic, further treatment efforts were abandoned. Related to Donor Site.—The fibula was selected for transfer in almost two thirds of the procedures in this series (39 patients) (Table 3). Four of the fibular transfers were compound osteocutaneous flaps. The iliac crest was the donor site in 20 patients. In one patient with a
flail upper extremity, a forearm osteocutaneous flap was successfully used for reconstruction of the femur. 17 Of the 39 patients who had fibular transfers, 28 (72%) had primary bone union. Two other patients had union after a further operation. Thus, the overall eventual union rate was 77%. Of the remaining nine patients with a fibulartransferthatfailedtoheal, four are still undergoing treatment, three have undergone amputation, and two are insufficiently symptomatic to warrant further surgical intervention. Of the 20 patients who had iliac crest transfers, 11 (55%) had primary union and 4 had union after a further surgical procedure. Therefore, 75% of patients in this group eventually had bone union. Of the five patients with an iliac crest transfer that has not healed, two are still undergoing treatment, one received alternative treat ment, one has undergone amputation, and one has died. Related to Vascular Anastomosis.~An accurate as sessment of patency of the vascular anastomoses during the postoperative period was not possible for all patients in this series. In no instance was arteriography used for this purpose. In 23 patients, an osteocutaneous com pound flap was used for the vascularized bone transfer. In these patients, accurate visual assessment of the vascular patency in the inclusive skin flap was possible. In this group, union was not attained in five patients, and the failure was related to vascular thrombosis in two of them. In another 23 patients, "Tc-diphosphonate bone scan-
Table 2.—Recipient Sites for Vascularized Bone Transfer and Related Results Result Recipient site
No. of patients
Primary union
Union after second operation
Tibia Femur Radius Pelvis Humerus Mandible Clavicle
23 16 5 5 5 4 2
13 10 5 4 3 4 1
4 2 0 0 0 0 0
Nonunion*
Failuret
4 3 0 0 2 0 0
2 1 0 1 0 0 1
•Patients are still undergoing treatment to achieve union, have minimal symptoms that do not necessitate further surgical intervention, or have undergone late amputation. tEarly amputation or alternative treatment undertaken.
VASCULARIZED BONE TRANSFER
Mayo Clin Proc, November 1985, Vol 60
733
Table 3,—Donor Sites for Vascularized Bone Transfer and Related Results Result Donor site Fibula Iliac crest Other (radius/ulna)
No. of patients
Primary union
Union after second operation
39* 20 1
28 11 1
2 4 0
Nonunion*
Failuret
6 3 0
3 2 0
•Patients are still undergoing treatment to achieve union, have minimal symptoms that do not necessitate further surgical intervention, or have undergone late amputation. tEarly amputation or alternative treatment undertaken. ΦΙη four patients, the fibular transfers were compound osteocutaneous flaps.
ning was used for assessment during the first postopera tive week. Of this group, 16 patients had positive scintil lation activity over the transferred bone segment, and all but 3 of these patients eventually had bone union. Of the seven patients with negative or equivocal scans, four had bone union. In addition, one patient underwent postop erative reexploration that confirmed vascular patency, and a satisfactory union was eventually achieved. In the remaining 13 patients, no assessment of the vascular anastomosis was possible; 10 of these patients eventually had bone union. COMPLICATIONS In addition to the aforementioned complications that related to failure, delayed union, nonunion, and recur rent sepsis, seven patients (12%) had complications re lated to the donor site. Three patients suffered a peroneal palsy after harvest of a fibula. In all three patients, the paralysis was transient and neurologic recovery was complete. One patient who underwent fibular transfer sustained an apparent stress fracture with displacement of the ipsilateral tibia 6 months postoperatively. This patient had poorly controlled diabetes mellitus but no other apparent abnormalities or obvious trauma to the involved tibia. One additional patient who underwent fibular transfer in combination with humeral allografting for proximal humeral reconstruction had deep wound sepsis early postoperatively. This complication necessi tated removal of all prosthetic hardware and the allograft, but the fibula remained well vascularized and was re tained. She had a satisfactory outcome with no residual deep sepsis and an asymptomatic stable fibrous non union of a scapulohumeral arthrodesis. In two patients who underwent iliac crest transfer, a hernia developed at the donor site. Both patients were minimally sympto matic, and neither patient required secondary repair or reconstruction. DISCUSSION The purpose of this review was to determine objectively the results of microvascular free bone transfer at our
institution. We are unaware of any similar study with which we could compare our results. In our analysis, we were particularly interested in those factors and variables that favorably or unfavorably influenced the clinical outcome. Identification of such factors may help prompt formulation of the specific indications for this procedure or may suggest appropriate modifications of the surgical technique. Overall, our experience suggests that vascularized bone transfer can be expected to result in uneventful bone union in 67% of patients. The eventual union rate after various procedures such as secondary bone grafting, secondary internal fixation, or electrical stimulation techniques is about 77%. These figures are somewhat lower than the 73% primary union and the 88% eventual union reported by Weiland and associates6 in a slightly smaller series of patients. Our results were best with limb reconstruction after resection of a bone tumor (87% primary union rate), with reconstruction of forearm or mandibular defects (100% primary union rate), and with the selection of a fibular donor site (72% primary and 77% ultimate union rates). In contrast, our results were poorest with limb recon struction after radical bone debridement for chronic os teomyelitis (40% primary and 60% ultimate union rates), with reconstruction of defects of the shoulder region (57% primary union rate for humerus and clavicle com bined), and with the selection of an iliac crest donor site (55% primary and 75% ultimate union rates). Recon struction of traumatic defects or those that involved the tibia, femur, or pelvis yielded intermediate results. We believe that the explanation for the differing results relates to the stability of the transferred bone, the use of additional bone-grafting material, and the adequacy of postoperative support and immobilization. In general, patients who underwent reconstruction after excision of a bone tumor had extremely stable internal fixation with plates or intramedullary nails, which was augmented with a conventional bone graft. In contrast, those patients who underwent reconstruction for osteomyelitis were managed with external fixation and minimal internal
734
VASCULARIZED BONE TRANSFER
Mayo Clin Proc, November 1985, Vol 60
hardware without supplementation by nonvascularized bone-grafting material. The fibula, because of its strong linear cortical structure, was advantageous for fixation with screws and hardware as well as fixation by intramedullary insertion of the fibular segment into the recipi ent defect (Fig. 1). The forearm was easily supported postoperatively by a long-arm cast, but the humerus and clavicle defied secure external immobilization even with a shoulder spica cast. Complications other than delayed union or nonunion were relatively minimal. Transient peroneal palsy after harvest of a fibula occurred in 3 of 39 patients (8%), and an iliac hernia developed in 2 of 20 patients (10%) who underwent iliac crest transfer. No serious vascular com plications were noted in either of these groups. Only one deep infection occurred among the patients who under went reconstruction for factors other than osteomyelitis. In this series, we were unable to correlate strongly the incidence of clinical success with the presence or ab sence of patency of the vascular anastomoses. Of the 14 patients who did not have a satisfactory bone union, 6 were thought to have patent anastomoses on the basis of sustained viability of an accompanying cutaneous flap or a positive bone scan. Vascular thrombosis was suspected because of necrosis of an accompanying skin flap or a negative bone scan in five patients, and no assessment of patency was possible in three.
REFERENCES
CONCLUSIONS In our experience, skeletal reconstruction by vascular ized bone transfer has proved to be a valuable procedure for patients unlikely to heal with standard bone-grafting techniques. Eventual union rates of at least 75% can be achieved, and the incidence of related complications is acceptable. We suggest that this procedure yields partic ularly good results in patients who are undergoing recon struction of the radius or mandible and in patients who are undergoing limb-salvage bone resection for a malig nant tumor.
15.
1. 2.
3. 4.
5.
6. 7.
8.
9.
10.
11. 12.
13. 14.
16.
17.
Gilbert A: Surgical technique: vascularized transfer of the fibular shaft. Int J Microsurg 1:100-102, 1979 Weiland A), Daniel RK: Microvascular anastomoses for bone grafts in the treatment of massive defects in bone. J Bone Joint Surg [Am] 61:98-104, 1979 P h o R W H : Free vascularised fibular transplant for replacement of the lower radius. J Bone Joint Surg |Br[ 61:362-365, 1979 Wood MB, Cooney WP III, Irons GB: Posttraumatic lower extrem ity reconstruction by vascularized bone graft transfer. Orthope dics 7:255-262, 1984 Weiland AJ, Kleinen HE, Kutz JE, Daniel RK: Free vascularized bone grafts in surgery of the upper extremity. J Hand Surg 4:129-144, 1979 Weiland AJ, Moore JR, Daniel RK: Vascularized bone autografts: experience with 41 cases. Clin Orthop 174:87-95, 1983 Wood MB, Cooney WP III: Vascularized bone segment transfers for management of chronic osteomyelitis. Orthop Clin North Am 15:461-472, 1984 Buncke HJ, Furnas D W , Gordon L, Achauer BM: Free osteocutaneous flap from a rib to the tibia. Plast Reconstr Surg 59:799-805, 1977 Taylor G l , Townsend P, Corlett R: Superiority of the deep circum flex iliac vessels as the supply for free groin flaps: clinical work. Plast Reconstr Surg 64:745-759, 1979 Biemer E, Stock W : Total thumb reconstruction: a one-stage reconstruction using an osteo-cutaneous forearm flap. Br J Plast Surg 36:52-55, 1983 Time Magazine: Medicine. January 14, 1985 TaylorGI, M i l l e r G D H , Ham FJ: The free vascularized bone graft: a clinical extension of microvascular techniques. Plast Reconstr Surg 55:533-544, 1975 Daniel RK: Free rib transfer by microvascular anastomoses (letter to the editor). Plast Reconstr Surg 59:737-738, 1977 Taylor Gl, Watson N: One-stage repair of compound leg defects with free, revascularized flaps of groin skin and iliac bone. Plast Reconstr Surg 61:494-506, 1978 TaylorGI, Townsend P, Corlett R: Superiority of the deep circum flex iliac vessels as the supply for free groin flaps: experimental work. Plast Reconstr Surg 64:595-604, 1979 Teot L, Bosse JP, Moufarrige R, Papillon J, Beauregard G: The scapula crest pedicled bone graft. Int J Microsurg 3:257-262, 1981 Mixter RC, W o o d M B : Closure of a defect of the femur with a compound free forearm transfer including both the radius and the ulna. Br J Plast Surg 36:470-472, 1983