Intercalary femur and tibia segmental allografts provide an acceptable alternative in reconstructing tumor resections

Intercalary femur and tibia segmental allografts were implanted in 59 consecutive patients after segmental resection-52 for malignant and seven for benign aggressive bone tumors. The patients were followed up for an average of 5 years. Allograft survival was determined with the Kaplan-Meier method. Infection, fracture, and nonunion rates were determined. The overall 5-year survivorship for the 59 intercalary allografts was 79%, and we found no significant differences between allograft survival in patients receiving or not receiving adjuvant chemotherapy. Infection and fracture rates were 5% and 7% respectively. From 118 host-donor junctions, 11 did not initially heal (9%). The nonunion rate (10 of 69 osteotomies) for diaphyseal junctions was higher than the rate (one of 49 osteotomies) for metaphyseal junctions. Although some patients required reoperations because of allograft complications, it seems that the use of intercalary allograft clearly has a place in the reconstruction of a segmental defect created by the resection of a tumor in the diaphyseal and /or metaphyseal portion of the femur or tibia.     

Reconstruction by bony allografts for malignant tumors of the skeleton at the end of growth

Summary Between Mai 1st, 1983 and December 1st, 1995, 57 bone tumors, mostly primitive and malignant have been referred to our department: there were 34 osteosarcomas and 15 chondrosarcomas. The primary treatment was 21 prosthesis, 11 bone allografts, 9 amputations or disarticulations, 8 Tikoff-Linberg procedures, 4 resections without reconstruction, 2 autografts reconstructions 1 spacer reconstruction and 1 Juvara technique.Among the 11 patients treated by bone allografts, there were 7 males and 4 females. The mean age was 27 years (range 12–70 years). The histological diagnosis was: osteosarcoma (6), chondrosarcoma (2), Ewing sarcoma (1), metastasis (1), recurrent giant cell tumor(1). The localisation was: femoral neck (1), femoral diaphysis (5), distal femur (2), proximal tibia (1), proximal humerus (2). The medical treatment of osteosarcomas and Ewing sarcomas included pre- and post-operative chemotherapy. The mean length of bone resection was 17.8 cm (range: 8–22 cm). Bone allografts were perforated, non irradiated, and cryopreserved at –196°C. Five allografts were intercalar femoral grafts, fixed with a Grosse and Kempf nail (2), or an AO blade plate, 2 allografts were intercalar femoro-tibial grafts (arthrodesis), with a titane nail, 2 allografts were osteo-chondral and ligamentar allografts, 1 in the distal femur (interlocking nail.) 1 in the proximal humerus (plate). 1 metaphyso-diaphyseal and tendinous allograft was the cuff of the cemented stem of a humeral prosthesis. 1 allograft was acetabular.Infectious and oncologic complications are non specific complications and occur with any reconstructive techniques. They belong to the surgery for malignant bone tumors. 3/11 patients (27%) have been reoperated for either a local recurrence, or a second malignant tumor or an infection. These major complications led to an amputation of the inferior limb in one patient (second malignant tumor) , and to an important handicape in the second patient despite a functional limb (infection). The patient with a local recurrence, was treated by a second-line chemotherapy and a second conservative surgery by an articular megaprosthesis. The present follow-up for this patient is 10 years from diagnosis, and 8 years from recurrence.Specific complications are related to the mechanical fragility of a dead bone, immunologically inert, the rehoming of which is very slow, partial and superficial. 4/11 patients (36%) were reoperated for fracture (in 2 osteo-chondral allografts), pseudarthrosis (1 tibio-femoral allograft) or pseudarthrosis and functional shrinkage (1 intercalar femoral allograft). In 3 of 4 cases, the function was restored or maintained at its previous level which was satisfactorily.Survival and disease-free survival: The mean follow-up was 62 months (range: 10–132 months). Two patients died from disease, and the third one exhibited lung metastases from an osteosarcoma.1 patient with a recurrent giant-cell tumor had no new recurrence, and 7 patients with malignant tumors were in first complete continuous remission. Of 6 osteosarcomas, the follow-up was between 7 and 11 years for 4 patients.When revised, all the 7 patients with intercalar allograft had an excellent or good functionnal result.Conclusion: We favour the reconstruction by cemented unmuffed megaprosthesis around the knee because it gives the most rapid functionnal recovery for these patients for whom the medical treatment is intensive and prolonged (osteosarcomas and Ewing sarcomas). Intercalar allograft is the unavoidable solution for some anatomical sites: its muscular surrounding is excellent at the thigh level, but it is poor between the femur and the tibia. Besides local oncologic complications, infection is the most dreadful complication. The reconstruction with an allograft exposes to the non union of the junctions, to stress fractures, to resorption which can lead to mechanical failure, and sometimes to host immune reactions against

---

Reconstruction par allogreffes osseuses pour tumeurs malignes du squelette en fin de croissanceL'expérience de l'Hôpital de Hautepierre (1983–1995)

     

Massive allografts in salvage revisions of failed total knee arthroplasties

Ten patients with failed total knee arthroplasties and severe bone loss were treated with massive whole distal femur and proximal tibial allografts in combination with prosthetic implants. Fourteen allografts were inserted either as invaginated or segmental grafts and were rigidly fixed to the host bone. Clinically and roentgenographically, 12 of 14 grafts (86%) seemed to have united to the host bone. The average range of motion was 92 degrees. Five patients developed complications; two of these involved the allograft (nonunion and fracture) and two were caused by inadequate healing at the ligament-allograft junction. One patient had a late infection. With careful planning and improved surgical techniques, these complications can be avoided. The massive allograft-prosthesis composite techniques is a viable reconstructive alternative worthy of further clinical trials.     

Clinical and functional outcomes of tibial intercalary allografts after tumor resection

Reconstruction after intercalary resection of the tibia is demanding due to subcutaneous location, poor vascularity of the tibia, and high infection rate. The purpose of this study was to evaluate the survivorship, complications, and functional outcome of intercalary tibial allograft reconstructions following tumor resections. Intercalary tibia segmental allografts were implanted in 26 consecutive patients after segmental resections. Patients were followed for an average of 6 years. Allograft survival was determined with the Kaplan-Meier method. Patient function was evaluated with the Musculoskeletal Tumor Society (MSTS) scoring system. Survivorship was 84% (95% confidence interval [CI], 98%-70%) at 5 years and 79% (95% CI, 63%-95%) at 10 years. Allografts were removed in 5 patients due to 3 infections and 2 local recurrences. Two patients showed diaphyseal nonunion, and 3 patients underwent an incomplete fracture; no allografts were removed in these patients. Average MSTS functional score was 29 points (range, 27-30 points). Despite the incidence of complications, this analysis showed an acceptable survivor-ship with excellent functional scores. The use of intercalary allograft has a place in the reconstruction of a segmental defect created by the resection of a tumor in the diaphyseal or metaphyseal portion of the tibia.     

Experimental model for allograft incorporation and allograft fracture repair.

This study describes a rat model of allograft osteotomy healing. An intercalary skeletal defect was created in adult Lewis rats by resecting a 2-cm segment of the femur in the diaphysis, including the periosteum and the cuff of muscle layers. The skeletal defects were replaced with fresh-frozen devascularized intercalary allografts from Sprague-Dawley rats. A transverse osteotomy was made in the middle of the allograft. The osteotomized segments were stabilized with an intramedullary threaded Kirschner wire, which allowed immediate ambulation. Radiographic and histological examination at 4 and 8 weeks revealed a characteristic healing process at three different interfaces. Radiographically, the distal metaphyseal host-donor junction healed faster than the proximal diaphyseal host-donor interface. The osteotomy site did not have evidence of an intramembranous or endochondral repair process. This model can serve as a baseline for assessing allograft incorporation and fracture repair.     

带血管腓骨复合异体骨修复长骨肿瘤切除后骨缺损

目的 探讨带血管腓骨复合异体骨重建长骨恶性肿瘤切除后骨缺损的临床结果.方法 2006年4月至2009年10月对19例四肢长骨恶性骨肿瘤患者行保肢手术,男11例,女8例;年龄11～37岁,平均(18.5±7.6)岁.肱骨5例、股骨7例、胫骨7例.肿瘤切除后骨缺损长度(13.2±4.3)cm,采用带血管自体腓骨复合大段异体...     

Long-term followup of proximal femoral allografts

Between 1972 and 1999, the orthopaedic service at the authors' institution treated 137 patients with proximal femoral bone lesions by resection and reconstruction with frozen allografts from cadavers. The data were entered into a computer program allowing a comprehensive analysis. Thirty-eight patients had proximal femoral osteoarticular allografts, 69 had allograft-endoprosthesis composites, 22 had intercalary allografts, and eight had an allograft arthrodesis. There were 74 complications in 54 of the 137 patients with allografts, which included 26 allograft fractures (19%), 15 infections (11%), and 20 nonunions (15%). The overall success rate for the patients with these procedures was 103 of 137 (75%) at a mean followup of 7.9 years +/- 5.6 years. If the eight patients with tumor recurrences (surgical failures rather than allograft failures) are not included, the success rate is 103 of 129 (80%). Eighty-three of these patients (55%) without any allograft complications who have been treated and followed up for at least 2 years had a 92% success rate. It is concluded that although allograft reconstruction after resection of the proximal femur for patients with aggressive or malignant tumors has a high complication rate, approximately 80% of the patients have a successful outcome.     

Allografts about the Knee in Young Patients with High-Grade Sarcoma

Reconstruction after resections for high-grade sarcomas about the knee in children and adolescents is a challenging problem because of the large soft tissue and skeletal defects, the effects of adjuvant therapy, and the potential for long-term use of the limb. One hundred sixteen patients, all 18 years or younger, with osteosarcoma or Ewing's sarcoma located between the middle femur and middle tibia, were treated with chemotherapy, resection, and allograft reconstruction. One hundred three patients with osteosarcoma and 13 patients with Ewing's sarcoma had 105 Stage II and 11 Stage III tumors. There were 72 osteoarticular grafts (39 femur, 33 tibia), 28 intercalary grafts (19 femur), seven allograft-prosthetic composites (all femur,) and nine allograft-arthrodeses (seven femur, two tibia). At latest followup, 49% of all of the allograft reconstructions were rated good or excellent, 14% were rated as fair, and 37% were failures. Sixteen percent had an infection develop. Twenty-seven percent of patients had a fracture, 34% had a nonunion, and 14 patients eventually required amputation. Reconstruction of large bone defects about the knee in young patients who are being treated with chemotherapy is difficult. Although complications significantly affect outcome, allografts are a viable option for reconstruction in children with high-grade sarcomas about the knee.     

Fresh osteochondral allografts for advanced giant cell tumors at the knee

Sixteen patients with advanced giant cell tumors presenting at the knee were treated with complete tumor resection and reconstruction using fresh osteochondral allografts. All patients had one or more of the following indications for tumor resection (as opposed to curettage): tumor recurrence, pathologic fracture, or destruction of the subchondral bone plate. At the 3–15-year follow-up period (mean, 9 years), two grafts have been revised to second fresh grafts because of fracture and one graft has been converted to an allograft-implant composite reconstruction. One joint was fused because of late infection. Functional assessment was carried out in 13 patients, and 8 were good or excellent, 4 were fair, and 1 was poor. The authors conclude that the fresh osteochondral allograft is a viabie treatment alternative to prosthetic arthroplasty in advanced, benign, aggressive bone tumors.     

Initial stability of circumferential meshes with impacted bone allografts for massive femoral defects

When the proximal femur is absent due to a failed femoral stem in total hip arthroplasty, impacted bone grafts contained within circumferential meshes could be an alternative reconstructive method. The purpose of this study was to analyse the initial resistance to axial and rotational forces in a fresh frozen bovine model with complete loss of the proximal femur reconstructed with a circumferential metal mesh, impacted bone allografts and a long cemented stem. Four bovine femurs with a complete proximal bone defect were reconstructed with a circumferential mesh, impacted bone grafts and a cemented stem. The results were compared with four intact femurs using the same implant. Under axial load, subsidence was observed at an average of 617 kg in the experimental group, and a cortical fracture occured at 1335 kg in the control group. Under rotational load, experimental femurs failed at an average of 79 kg and the control femurs fractured at 260 kg. This model provided 50% of the resistance to axial load and 30% of the resistance to rotational load compared to an intact femur, which is enough to resist physiological load. This stability encourages the use of circumferential meshes, impacted bone allografts and cemented stems in revision hip surgery with massive bone loss.     

冷冻异体骨移植治疗骨肿瘤切除后骨缺损

目的探讨冷冻异体骨移植在治疗骨肿瘤切除后骨缺损中的作用。方法1992年3月至2002年9月应用深低温保存同种异体骨治疗骨肿瘤切除后骨缺损164例患者,其中男性90例,女性74例,年龄12～65岁,平均20岁。疾病种类以骨巨细胞瘤和骨肉瘤为主。外科治疗以Enneking外科分期标准为原则。主要发病部位为股骨上端、股骨下端、胫骨上端及胫骨上端及肱骨上端。异体骨均为北京骨科创伤研究所骨库提供。重建方式为1／2关节移植术95例,1／4关节移植术15例,人工关节．异体骨复合物12例,大块骨移植23例,骨干节段移植15例,骨盆骨移植4例。结果所有患者均获得随访,平均随访时间47个月。治疗满意率74．4％（122／164）,复发率12．8％（21／164）,感染率11．0％（18／164）,骨端不愈合23．2％（38／164）,内固定折断6．7％（11／164）,关节不稳定7．9％（13／164）,异体骨骨折6．7％（11／164）,死亡6．1％（10／164）,最终保肢率91．5％（150／164）。结论深低温保存异体骨降低了异体骨的免疫原性,具有与自体骨近似的骨传导性及骨诱导性,可保留韧带附丽以供软组织重建应用。但异体骨移植具有较高并发症,只有在移植骨与宿主完全愈合后,方可发挥作用。     

Fresh osteochondral allografts for post-traumatic knee defects: Surgical technique

Fresh osteochondral allografts for post-traumatic knee defects have been carried out at our institution since 1972. These grafts are performed for unipolar traumatic defects that involve a significant amount of both bone and cartilage in young patients who are not suitable candidates for prosthetic replacement. These grafts are done fresh within 24 hours of the death of the donor. If there is an associated deformity in the knee, then a realignment osteotomy is carried out through the femur if the deformity is valgus, and through the tibia if the deformity is varus. One hundred and twenty six knees in 123 patients were reconstructed with this procedure, with an average follow-up of 7.5 years. Survivorship analysis showed a 95% success rate at 5 years, 71% at 10 years, and 66% at 20 years.     

Size and position of a single condyle allograft influence knee kinematics.

An optimal match for size and shape between the donor femur and the host knee is considered a critical factor influencing the outcome of a knee allograft implantation. An in vitro allograft model was developed to determine the influence of the size and position of a lateral distal femoral condylar allograft on knee kinematics. Functional knee motion was simulated in a cadaver host knee in the intact state after removing and reimplanting the native lateral condyle of the distal femur and after serially replacing the native condyle with eight donor allografts. Each allograft was first tested in an optimal position and subsequently shifted 3 mm proximal and 3 mm distal to the joint line to quantify changes in joint kinematics due to the position of the allograft. The intact knee and the knee with the ideally implanted native allograft followed similar kinematic trends. Decreasing the width of the allograft increased the valgus knee orientation at full flexion, translated the tibia posteriorly at full extension, and externally rotated the tibia throughout knee flexion. The proximal shift in allograft position increased the valgus orientation at full extension, translated the tibia posteriorly at mid-flexion, and externally rotated the tibia throughout flexion. The distal shift in position had the opposite effect on the kinematics of the proximal shift. These results indicate that improving techniques for preoperative size-matching and intraoperative allograft placement may help to reduce biomechanical complications following implantation of the allograft.     

Fractures in large-segment allografts

Segment skeletal defects that result from resection of a malignant bone neoplasm commonly are reconstructed with large segment allografts. Excellent functional results after these reconstructions and significant complications have been reported. Although it is known that a common complication seen with the use of allografts is allograft fracture, the factors associated with allograft fracture are not entirely clear. In this study, the hypothesis was examined that allograft reconstructions, which use internal fixation devices that penetrate the cortex of the allograft, are associated with an increased risk of fracture. Findings from large segment allograft reconstructions in 74 patients with a minimum followup of 36 months were studied. These 74 patients include 35 patients whose outcomes were reported previously and now have additional followup and 39 patients whose outcomes are being reported for the first time. Thirty-one of the 74 (42%) allografts fractured, and the mean time to fracture was 26 months. When the fixation techniques resulted in cortical penetration of the allograft, fractures occurred in 27 of the 43 (63%) allografts, and when fixation of the graft to the host bone required no cortical penetration, only four of the 31 (13%) allografts fractured. Fractures occurred in 12 of 15 (80%) tibial allografts and in only two of 17 (12%) proximal femoral allografts; however, the anatomic site was not statistically independent of method of fixation because 14 of the 15 tibial grafts had cortical penetration and 15 of the 17 proximal femoral grafts had no cortical penetration. The authors' analysis indicates that internal fixation devices that require cortical penetration are associated with an increased risk of allograft fracture.     

The effect of adjuvant chemotherapy on osteoarticular allografts

Two hundred lower extremity osteoarticular allografts (in 200 patients) performed for aggressive or malignant bone tumors between 1976 and 1997 included 124 grafts of the distal femur, 46 of the proximal tibia, and 30 of the proximal femur. Seventy-four patients did not receive chemotherapy, and 126 received either adjuvant or neoadjuvant therapy. The diagnoses, mean ages, and length of followup were different for the two groups because most of the patients in the chemotherapy group had osteosarcoma, whereas the largest number in the control group had chondrosarcoma or parosteal osteosarcoma. The extent of the surgery was essentially the same for both patient groups, as is reflected by a low recurrence rate (7% for the control and 6% for the chemotherapy group). A statistical comparison of the various parameters showed that the infection, fracture, and amputation rates were the same, but the nonunion rate was markedly increased in the patients who received chemotherapy (32% versus 12%). Cox regression and Kaplan-Meier studies showed that chemotherapy had a significant effect on outcome, with the success rates for the two groups being quite different (72% versus 56%). The results for the distal femur showed a greater effect than for either the proximal tibia or the proximal femur. Analysis of these data suggest the distal femur is perhaps the most prone to healing problems, possibly based in part on the extent of the surgery. A final study supports the concept that the results improved in later years, suggesting a modification or application of the drugs used, better selection of patients, and improvements in surgical technique.     

Unicondylar osteoarticular allografts of the knee

BACKGROUND: In the management of a resected distal femoral or proximal tibial condyle as the result of tumor or trauma, a unicondylar osteoarticular allograft is currently the only reconstructive option that avoids the sacrifice of the unaffected condyle. The purposes of this study were to perform a survival analysis of unicondylar osteoarticular allografts of the knee and to evaluate the complications. METHODS: We retrospectively reviewed the results of forty large unicondylar osteoarticular allograft procedures in thirty-eight patients who were followed for a mean of eleven years. Twenty-nine allografts were femoral transplants and included eleven medial and eighteen lateral femoral condyles. Eleven allografts were tibial transplants, including four medial and seven lateral tibial condyles. The procedure was performed after a tumor resection in thirty-six patients and to replace condylar loss after a severe open fracture in the remaining two patients. Complications were analyzed, and allograft survival from the date of implantation to the date of revision or the time of the latest follow-up was determined. Functional and radiographic results were documented according to the Musculoskeletal Tumor Society scoring system at the time of the latest follow-up. RESULTS: One patient died of tumor-related causes without allograft failure before the two-year follow-up evaluation. The global rate of allograft survival at both five and ten years was 85%, with a mean follow-up of 148 months. In six patients, the allografts were removed at an average of twenty-six months (range, six to forty-eight months) and these were considered failures. All six patients underwent a second allograft procedure including two new unicondylar and four bicondylar reconstructions. The mean radiographic score for the thirty-three surviving allografts evaluated was 89%, with an average functional score of 27 of a possible 30 points. CONCLUSIONS: Unicondylar osteoarticular allografts of the knee appear to be a reliable alternative for patients in whom reconstruction of massive osteoarticular bone loss is limited to one condyle of the femur or the tibia.     

The effect of intramedullary polymethylmethacrylate on healing of intercalary cortical allografts in a canine model.

The purpose of this study was to evaluate the effect of intramedullary polymethylmethacrylate (PMMA) bone cement on the healing of intercalary allografts. Thirteen adult beagles had bilateral intercalary femoral allografts implanted. The medullary canal of one randomly assigned allograft in each dog was filled with PMMA. Healing was followed clinically and femora were evaluated radiographically, biomechanically, histologically, and histomorphometrically 9 months after surgery. There was an increased percent of eroded surface at the endosteal area of the center region of grafts containing PMMA and there was an increased percent osteoblast surface in this area in grafts not containing PMMA. There was an increased percent eroded surface at the periosteal area in the center region in grafts not containing PMMA and there was an increased percent osteoblast surface at the periosteal area in the graft adjacent to the host junction in grafts containing PMMA. There was no significant difference between PMMA-treated and untreated allografts in any other parameters measured. The results from this study suggest that, although the pattern of incorporation is altered, intramedullary PMMA does not appear to effect allograft healing adversely.     

Vascularized whole knee joint allografts in rabbits immunosuppressed with cyclosporin A

To develop the surgical model, whole knee joints including the distal femur, proximal tibia, and joint capsule, were raised on a vascular pedicle and then replanted at the same site. Rigid fixation of the bones was achieved using two mini-plates on the tibia and femur. Revascularization of the knee was accomplished by end-to-end anastomosis of the popliteal vessels using standard microvascular techniques, and the vascular and neural supplies to the lower leg and foot were preserved. A total of 21 vascularized whole knee allografts were then similarly performed on a microvascular pedicle between two incompatible strains of rabbit. In a control group of six adult animals, no immunosuppression was administered. Two of these joints were harvested at 1 week and had patent popliteal arteries. The remaining four joints were harvested at 2-3 weeks when they were deteriorating and were found to have occluded popliteal vessels by arteriography. Eight adult allograft recipients were immunosuppressed with cyclosporin A (CyA) at 15 mg/kg per day. One allograft failed at 10 days due to femoral fracture. None of the remaining seven were rejected acutely, and three of them had patent vessels by arteriography and live bone and cartilage by light microscopy when harvested 100 days after transplantation. In another group, seven knee joints were allografted into immature rabbits immunosuppressed with CyA. Again, none rejected acutely, and 90 days later two of the seven allografts had patent vessels by arteriography, growth by serial radiographs, and live bone and cartilage by histological examination. This pilot study suggests that CyA will be useful as an immunosuppressive agent in the study of vascularized bone and cartilage transplantation, and that experimental epiphyseal plate allografting is possible in rabbits.