Biological reconstruction after excision, irradiation and reimplantation of diaphyseal tibial tumours using an ipsilateral vascularised fibular graft

Factors affecting the incorporation of extracorporeally irradiated autograft for the treatment of bone tumours-a retrospective analysis from a tertiary referral centre

PURPOSE

Re-implantation of the tumor bearing autograft following extracorporeal radiation therapy (ECRT) has been established as an oncologically safe biological reconstruction technique following resection of bone sarcomas. However, factors affecting the ECRT graft-host bone incorporation have not been fully investigated. An insight into the factors that influence graft incorporation can circumvent the complications and increase graft survival.

METHODS

A total of 96 osteotomies in 48 patients with intercalary resections of primary extremity bone sarcomas (mean age 15.8 years, mean follow-up 42.1 months) were analyzed retrospectively for factors ECRT autograft-host bone union.

RESULTS

On univariate analysis, age < 20 years, metaphyseal osteotomy site, V-shaped diaphyseal osteotomy, and use of additional plate at diaphyseal osteotomy had a significantly faster time to union, while gender, tumour type, bone involved, resection length, chemotherapy, type of fixation, and use of intra-medullary fibula did not influence union time. In multivariate analysis, V-shaped diaphyseal osteotomy and use of additional plate at diaphyseal ostetomy were the independent factors with favourable time to union. None of the analyzed factors was found to have a significant effect on the union rate. The major complications were non-union in 11.4% patients, graft failure in 2.1%, infection in 12.5%, and soft tissue local recurrences in 14.5% patients.

CONCLUSION

Modified diaphyseal osteotomy and augmentation of the stability of the reconstruction using additional small plates enhance the incorporation of ECRT autograft.

Psoralen alleviates radiation-induced bone injury by rescuing skeletal stem cell stemness through AKT-mediated upregulation of GSK-3β and NRF2

BACKGROUND

Repairing radiation-induced bone injuries remains a significant challenge in the clinic, and few effective medicines are currently available. Psoralen is a principal bioactive component of Cullen corylifolium (L.) Medik and has been reported to have antitumor, anti-inflammatory, and pro-osteogenesis activities. However, less information is available regarding the role of psoralen in the treatment of radiation-induced bone injury. In this study, we explored the modulatory effects of psoralen on skeletal stem cells and their protective effects on radiation-induced bone injuries.

METHODS

The protective effects of psoralen on radiation-induced osteoporosis and irradiated bone defects were evaluated by microCT and pathological analysis. In addition, the cell proliferation, osteogenesis, and self-renewal of SSCs were explored. Further, the underlying mechanisms of the protective of psoralen were investigated by using RNA sequencing and functional gain and loss experiments in vitro and in vivo. Statistical significance was analyzed using Student's t test. The one-way ANOVA was used in multiple group data analysis.

RESULTS

Here, we demonstrated that psoralen, a natural herbal extract, mitigated radiation-induced bone injury (irradiation-induced osteoporosis and irradiated bone defects) in mice partially by rescuing the stemness of irradiated skeletal stem cells. Mechanistically, psoralen restored the stemness of skeletal stem cells by alleviating the radiation-induced suppression of AKT/GSK-3β and elevating NRF2 expression in skeletal stem cells. Furthermore, the expression of KEAP1 in skeletal stem cells did not significantly change in the presence of psoralen. Moreover, blockade of NRF2 in vivo partially abolished the promising effects of psoralen in a murine model of irradiation-induced osteoporosis and irradiated bone regeneration.

CONCLUSIONS

In summary, our findings identified psoralen as a potential medicine to mitigate bone radiation injury. In addition, skeletal stem cells and AKT-GSK-3β and NRF2 may thus represent therapeutic targets for treating radiation-induced bone injury.

Ferulic acid promotes bone defect repair after radiation by maintaining the stemness of skeletal stem cells

The reconstruction of irradiated bone defects after settlement of skeletal tumors remains a significant challenge in clinical applications. In this study, we explored radiation‐induced skeletal stem cell (SSC) stemness impairments and rescuing effects of ferulic acid (FA) on SSCs in vitro and in vivo. The immunophenotype, cell renewal, cell proliferation, and differentiation of SSCs in vitro after irradiation were investigated. Mechanistically, the changes in tissue regeneration‐associated gene expression and MAPK pathway activation in irradiated SSCs were evaluated. The regenerative capacity of SSCs in the presence of FA in an irradiated bone defect mouse model was also investigated. We found that irradiation reduced CD140a‐ and CD105‐positive cells in skeletal tissues and mouse‐derived SSCs. Additionally, irradiation suppressed cell proliferation, colony formation, and osteogenic differentiation of SSCs. The RNA‐Seq results showed that tissue regeneration‐associated gene expression decreased, and the Western blotting results demonstrated the suppression of phosphorylated p38/MAPK and ERK/MAPK in irradiated SSCs. Notably, FA significantly rescued the radiation‐induced impairment of SSCs by activating the p38/MAPK and ERK/MAPK pathways. Moreover, the results of imaging and pathological analyses demonstrated that FA enhanced the bone repair effects of SSCs in an irradiated bone defect mouse model substantially. Importantly, inhibition of the p38/MAPK and ERK/MAPK pathways in SSCs by specific chemical inhibitors partially abolished the promotive effect of FA on SSC‐mediated bone regeneration. In summary, our findings reveal a novel function of FA in repairing irradiated bone defects by maintaining SSC stemness and suggest that the p38/MAPK and ERK/MAPK pathways contribute to SSC‐mediated tissue regeneration postradiation.

Reconstruction of intercalary bone defect after resection of malignant bone tumor

Due to accurate preoperative imaging techniques, early diagnosis and effective chemotherapy, many tumors arising in the metaphyseo-diaphyseal regions of long bones can be segmentally resected with joint preservation. The intercalary resection of malignant bone tumor results in a bone defect which can represent a challenging reconstructive problem. The most commonly used surgical reconstructive options for these defects include biologic reconstructions such as allografts, vascularized fibular grafts, autogenous extracorporeally devitalized tumor bearing bone graft, combination of allografts or devitalized autografts with vascularized fibular grafts, segmental bone transport, or induced membrane technique. Nonbiologic reconstructions, on the other hand, use intercalary endoprostheses. Every patient should be carefully evaluated and the reconstructive option should be individually selected. The aim of this article is to discuss the surgical options of reconstruction of bone defects after intercalary resection of malignant bone tumors with reviewing of their indications, advantages, disadvantages and complications.

Managing large bone defects in children: a systematic review of the 'induced membrane technique'

Thirty years after its description by Masquelet in 1986, this is the first systematic review aiming to critically evaluate the 'induced membrane technique' effectiveness in achieving bone union in children. Only six papers fulfilled our inclusion criteria (54 patients). The relatively small number of reported cases did not allow a formal meta-analysis. The tibia was the most involved bone. Most frequent aetiologies were congenital pseudoarthrosis and tumour resections. Although effective in achieving bone healing in ∼91% of the patients (bone defects ≤24 cm long), the induced membrane technique was associated with a high rate of complications (54% of patients).

LEVEL OF EVIDENCE

IV.

Intraoperative Extracorporeal Irradiation and Frozen Treatment on Tumor-bearing Autografts Show Equivalent Outcomes for Biologic Reconstruction

BACKGROUND

Immediately recycling the resected bone segment in a biologic limb salvage reconstruction is an option after wide resection of bone. Intraoperative extracorporeal irradiation and freezing are the two major tumor-killing techniques applied on the fresh tumor-bearing autografts. However, graft-derived tumor recurrence and complications are concerns affecting graft survival.

QUESTIONS/PURPOSES

We therefore asked: (1) Is there a difference in the proportion of patients achieving union by 18 months after surgery between the groups with extracorporeal-irradiated autografts and frozen-treated autografts? (2) Is there any difference in the frequency of graft-related complications for patients receiving either an extracorporeal-irradiated or a frozen-treated autograft? (3) Is there a difference between the techniques in terms of graft-derived recurrence? (4) Are there differences in failure-free grafts, and limb and overall survivorship between autografts treated by extracorporeal irradiation or by freezing?

METHODS

During the study period we treated a total of 333 patients with high-grade osteosarcoma. One hundred sixty-nine patients were excluded. Overall, 79 of the enrolled 164 patients received recycled autografts treated with extracorporeal irradiation whereas the other 85 received frozen-treated autografts. The mean followup was 82 ± 54 months for the extracorporeal irradiation group and 70 ± 25 months for the frozen autograft group, and one patient was lost to followup. Complications and graft failure (revision required for primary graft removal) were characterized by adapting the International Society of Limb Society (ISOLS) system modified for inclusion of biologic and expandable reconstruction. The primary study endpoints were the proportion of patients in each group who achieved radiographic union, and had an ISOLS grade of fair or good host graft fusion at 6, 9, 12, and 18 months after surgery. Five-year survival data for graft failure and limb amputation were analyzed by a cumulative incidence function regression model whereas the Kaplan-Meier function was used to test the 5-year overall survival rate between the two techniques.

RESULTS

With the numbers available, no differences were found in the accumulated proportion of patients achieving union between the groups at 6, 9, 12, and 18 months. Radiographic evaluation did not show differences in the average scores of compared criteria. However in the subchondral bone subcriterion, more patients receiving frozen-treated autografts had higher scores (p = 0.03). Complications leading to a second surgery were not different between extracorporeal irradiation and frozen autografts in aspects of soft tissue failure (Type 1B), nonunion (Type 2B), structural failure (Type 3A and Type 3B), or infection (Type 4A and Type 4B). No graft-originating tumor recurrence was found and there was no difference in Type 5A tumor progression originating from soft tissue in the groups (odds ratio, 0.8; 95% CI, 0.3-2.1; p = 0.7). Neither group showed a difference in the cumulative incidence for graft failure and limb amputation. Five-year overall survival rates were 83% and 84% (p = 0.69) for extracorporeal-irradiated and frozen autografts respectively. A decrease in survivorship was seen at 50 to 100 months after surgery for the extracorporeal irradiation group.

CONCLUSION

We segregated the ISOLS criteria evaluating the graft-mediated tumor progression into host- or graft-derived complications (Types 5B and 5C) in this study. With the available data, there was no difference in the incidence of tumor recurrence derived from irradiation- or frozen-treated autografts. Ongoing evaluations comparing 10-year survivorship for both groups will be helpful to elucidate the possible difference found after 100 months.

LEVEL OF EVIDENCE LEVEL

III, therapeutic study.

Short-term outcomes of reconstruction subsequent to intercalary resection of femoral diaphyseal metastatic tumor with pathological fracture: Comparison between segmental allograft and intercalary prosthesis

Reconstruction of bone defects following femoral diaphyseal tumor resection is challenging. Segmental allograft (SA) and intercalary prosthesis (IP) are the most common reconstruction methods for femoral diaphyseal metastatic tumors with pathological fracture. However, whether the complications and functional outcomes differ between SA and IP remains unclear. To compare the clinical outcomes and complications for patients treated with SA reconstruction or IP replacement for femoral shaft tumors, 34 patients who had undergone intercalary resection for metastatic tumor with pathological fracture in the femoral diaphysis were evaluated. Of these, 18 had received SA and 16 IP. There were 11 males, and 24 females, with a mean age of 64.5±11.3 years. The most common sites of primary metastases were lung (26.5%), breast (17.6%) and liver (14.7%). The visual analog scale (VAS), implant-related complications and the Musculoskeletal Tumor Society (MSTS) scores for each patient were collected. The follow-up period for patients ranged from 2 to 27 months. At the most recent follow-up, 28 patients had succumbed to mortality, with a mean survival time of 6.9±3.7 months for the IP group and 7.4±3.0 months for the SA group. Patients with IP had a significantly shorter time to full weight bearing and hospitalization time than those who received SA (P=0.003 and P=0.002, respectively). The rates of overall complications and implant-related complications were significantly lower for IP as compared with SA (18.8 vs. 66.7%, P=0.007; 12.5 vs. 55.6%, P=0.013). The reoperation rate of the SA group was higher than that of the IP group (38.9 vs. 12.5%), however the difference between the two groups was statistically insignificant (P=0.125). MSTS scores were significantly higher for the IP group as compared with the SA group at one month after surgery (IP, 26.7±1.6 vs. SA, 20.3±1.5; P<0.05), without a significant difference at the final follow-up. There were no statistically significant differences in age, sex, length of resection, follow-up time, operative time or blood loss between the two groups. In summary, IP reconstruction may provide improved early functional outcomes and fewer early complications, particularly for patients with a shorter life expectancy due to femoral metastatic tumors with pathological fracture.

Understanding the potentiality of accelerator based-boron neutron capture therapy for osteosarcoma: dosimetry assessment based on the reported clinical experience

BACKGROUND

Osteosarcoma is the most frequent primary malignant bone tumour, and its incidence is higher in children and adolescents, for whom it represents more than 10% of solid cancers. Despite the introduction of adjuvant and neo-adjuvant chemotherapy that markedly increased the success rate in the treatment, aggressive surgery is still needed and a considerable percentage of patients do not survive due to recurrences or early metastases. Boron Neutron Capture Therapy (BNCT), an experimental radiotherapy, was investigated as a treatment that could allow a less aggressive surgery by killing infiltrated tumour cells in the surrounding healthy tissues. BNCT requires an intense neutron beam to ensure irradiation times of the order of 1 h. In Italy, a Radio Frequency Quadrupole (RFQ) proton accelerator has been designed and constructed for BNCT, and a suitable neutron spectrum was tailored by means of Monte Carlo calculations. This paper explores the feasibility of BNCT to treat osteosarcoma using this neutron source based on accelerator.

METHODS

The therapeutic efficacy of BNCT was analysed evaluating the dose distribution obtained in a clinical case of femur osteosarcoma. Mixed field dosimetry was assessed with two different formalisms whose parameters were specifically derived from radiobiological experiments involving in vitro UMR-106 osteosarcoma cell survival assays and boron concentration assessments in an animal model of osteosarcoma. A clinical case of skull osteosarcoma treated with BNCT in Japan was re-evaluated from the point of view of dose calculation and used as a reference for comparison.

RESULTS

The results in the case of femur osteosarcoma show that the RFQ beam would ensure a suitable tumour dose painting in a total irradiation time of less than an hour. Comparing the dosimetry between the analysed case and the treated patient in Japan it turns out that doses obtained in the femur tumour are at least as good as the ones delivered in the skull osteosarcoma. The same is concluded when the comparison is carried out taking into account osteosarcoma irradiations with photon radiation therapy.

CONCLUSIONS

The possibility to apply BNCT to osteosarcoma would allow a multimodal treatment consisting in neo-adjuvant chemotherapy, high-LET selective radiation treatment and a more conservative surgery.

[Extracorporeal irradiation : Reimplantation of bone segments in the treatment of malignant bone tumours]

BACKGROUND

Malignant bone tumors themselves and the wide resection required because of them may cause huge bone defects in the bone segment involved. Autologous bone grafts are a reliable option to cover these defects in many cases but their availability is limited. Besides common alternative reconstruction methods, including the use of allografts and/or prostheses, especially extracoroporeal irradiation (ECI) and reimplantation of the bone segment involved is attracting increasingly more attention nowadays.

DISCUSSION

In the following, we report on indications/contraindications, details of the operative technique, as well as the recommended rehabilitation regime of ECI. Furthermore, we compare our own results with those published in the recent literature. Especially the advantages and disadvantages of this method, the risks and the complications are illustrated and critically discussed.

CONCLUSION

Extracorporeal irradiation of a tumor bearing bone segment is a valuable alternative reconstruction technique following tumor resections of the pelvis, femur and tibia, with encouraging results with respect to local control, complication risks and functional outcome.

Outcomes of Intercalary Prosthetic Reconstruction for Pathological Diaphyseal Femoral Fractures Secondary to Metastatic Tumors

OBJECTIVE

To evaluate the clinical outcomes and complications of segmental prosthetic reconstruction for pathological diaphyseal femoral fractures secondary to metastatic tumors.

METHODS

Between 2011 and 2015, we retrospectively evaluated 16 patients (6 men and 10 women; 64.5 ± 11.4 years old at diagnosis) who underwent prosthetic reconstruction after segmental resection of diaphyseal femoral fractures due to metastatic lesions. Visual analog scale (VAS), functional outcomes, implant-related complications, and Mean postoperative Musculoskeletal Tumor Society (MSTS) score for each patient were collected.

RESULTS

The mean length of bone defect was 10.2 ± 2.6 cm (range, 8-16 cm); follow-up was 9 ± 6.8 months (range, 2-25 months) for all patients, and 24 months (23 and 25 months) for the 2 patients still alive. At final follow-up, 14 patients were dead, indicating a mean survival of 6.9 ± 3.6 months (range, 2-14 months). Mean preoperative VAS score was 8.5 ± 1.0, which decreased to 2.5 ± 1.3 at day 2 postoperatively, indicating significant pain relief (P < 0.05). The MSTS score for lower extremities was 84.6% (range, 73%-90%). The range of motion and function of adjacent joints was within the normal limits in all cases. Three patients (33%) developed complications, including aseptic loosening because of disease progression (1), infection (1), and peri-prosthesis fracture (1).

CONCLUSION

These findings demonstrated that this approach greatly relieves pain, and yields satisfactory functional outcomes with fewer complications in patients with pathological femoral fractures secondary to metastatic tumors; however, survival was not significantly improved.

Surgical Innovation in Sarcoma Surgery

The field of orthopaedic oncology relies on innovative techniques to resect and reconstruct a bone or soft tissue tumour. This article reviews some of the most recent and important innovations in the field, including biological and implant reconstructions, together with computer-assisted surgery. It also looks at innovations in other fields of oncology to assess the impact and change that has been required by surgeons; topics including surgical margins, preoperative radiotherapy and future advances are discussed.

Extracorporeally frozen tumour-bearing bone combined with free vascularised fibula for the intercalary reconstruction of femoral defect after resection of bony sarcoma

BACKGROUND

With the improved survival for patients with bone sarcomas, there is a trend to reconstruct intercalary femur defects using biologic techniques. This study examined whether the results of a frozen femur autograft with vascularised fibula are comparable to other reconstructive options in terms of the functional outcomes and the complications.

MATERIALS AND METHODS

Between 2008 and 2012, eight patients with bony sarcoma of the femur were subjected to reconstruction with a recycled frozen autograft combined with a vascularised fibula flap inside. The oncologic and functional results were analysed retrospectively.

RESULTS

The mean follow-up was 48.7 months (37-71). The oncologic results were continuously disease free in five patients; there was no evidence of disease in one, one patient was alive with disease and another died of the disease. The average length of defect was 13.6 cm (9-21). Bone union was achieved in all cases. The mean time to bone union was 7.9 months (5-19) and to full weight bearing was 7.8 months (6-11). There was no infection or construct fracture in this series. Two complications were observed. One tumour recurrence in soft tissue was treated with reresection. One tibia fracture was successfully managed with cast immobilisation. The average Musculoskeletal Tumor Society functional score was 95% (27-30). The construct was intact in all patients.

CONCLUSIONS

Vascularised fibular flap combined with frozen autografts is a dependable and durable option for the reconstruction of large bony defects after femoral sarcoma resection. It had the merits of reliable bone union and low complications, which compare well with other biological reconstructions. Evidence Rating Scale for Therapeutic Studies Level IV, therapeutic study.

Successful correction of tibial bone deformity through multiple surgical procedures, liquid nitrogen-pretreated bone tumor autograft, three-dimensional external fixation, and internal fixation in a patient with primary osteosarcoma: a case report

Background

In a previous report, we described a method of reconstruction using tumor-bearing autograft treated by liquid nitrogen for malignant bone tumor. Here we present the first case of bone deformity correction following a tumor-bearing frozen autograft via three-dimensional computerized reconstruction after multiple surgeries.

Case presentation

A 16-year-old female student presented with pain in the left lower leg and was diagnosed with a low-grade central tibial osteosarcoma. Surgical bone reconstruction was performed using a tumor-bearing frozen autograft. Bone union was achieved at 7 months after the first surgical procedure. However, local tumor recurrence and lung metastases occurred 2 years later, at which time a second surgical procedure was performed. Five years later, the patient developed a 19° varus deformity and underwent a third surgical procedure, during which an osteotomy was performed using the Taylor Spatial Frame three-dimensional external fixation technique. A fourth corrective surgical procedure was performed in which internal fixation was achieved with a locking plate. Two years later, and 10 years after the initial diagnosis of tibial osteosarcoma, the bone deformity was completely corrected, and the patient’s limb function was good.

Conclusion

We present the first report in which a bone deformity due to a primary osteosarcoma was corrected using a tumor-bearing frozen autograft, followed by multiple corrective surgical procedures that included osteotomy, three-dimensional external fixation, and internal fixation.

Vascularised or non-vascularised autologous fibular grafting for the reconstruction of a diaphyseal bone defect after resection of a musculoskeletal tumour

Resection of a primary sarcoma of the diaphysis of a long bone creates a large defect. The biological options for reconstruction include the use of a vascularised and non-vascularised fibular autograft. The purpose of the present study was to compare these methods of reconstruction. Between 1985 and 2007, 53 patients (26 male and 27 female) underwent biological reconstruction of a diaphyseal defect after resection of a primary sarcoma. Their mean age was 20.7 years (3.6 to 62.4). Of these, 26 (49 %) had a vascularised and 27 (51 %) a non-vascularised fibular autograft. Either method could have been used for any patient in the study. The mean follow-up was 52 months (12 to 259). Oncological, surgical and functional outcome were evaluated. Kaplan-Meier analysis was performed for graft survival with major complication as the end point. At final follow-up, eight patients had died of disease. Primary union was achieved in 40 patients (75%); 22 (42%) with a vascularised fibular autograft and 18 (34%) a non-vascularised (p = 0.167). A total of 32 patients (60%) required revision surgery. Kaplan-Meier analysis revealed a mean survival without complication of 36 months (0.06 to 107.3, sd 9) for the vascularised group and 88 months (0.33 to 163.9, sd 16) for the non-vascularised group (p = 0.035). Both groups seem to be reliable biological methods of reconstructing a diaphyseal bone defect. Vascularised autografts require more revisions mainly due to problems with wound healing in distal sites of tumour, such as the foot.

Autoclaved tumor bone for skeletal reconstruction in paediatric patients: a low cost alternative in developing countries

We reviewed in this series forty patients of pediatric age who underwent resection for malignant tumors of musculoskeletal system followed by biological reconstruction. Our surgical procedure for reconstruction included (1) wide en bloc resection of the tumor; (2) curettage of tumor from the resected bone; (3) autoclaving for 8 minutes (4) bone grafting from the fibula (both vascularized and nonvascularized fibular grafts used); (5) reimplantation of the autoclaved bone into the host bone defect and fixation with plates. Functional evaluation was done using MSTS scoring system. At final followup of at least 18 months (mean 29.2 months), 31 patients had recovered without any complications. Thirty-eight patients successfully achieved a solid bony union between the graft and recipient bone. Three patients had surgical site infection. They were managed with wound debridement and flap coverage of the defect. Local recurrence and nonunion occurred in two patients each. One patient underwent disarticulation at hip due to extensive local disease and one died of metastasis. For patients with non-union, revision procedure with bone graft and compression plates was successfully used. The use of autoclaved tumor grafts provides a limb salvage option that is inexpensive and independent of external resources and is a viable option for musculoskeletal tumor management in developing countries.

Bilateral fibular graft: biological reconstruction after resection of primary malignant bone tumors of the lower limb

This paper deals with bilateral vascularized fibular grafts (BVFG) as a method for reconstruction of metadiaphyseal defects of the femur and tibia in young patients suffering from malignant bone tumors of the lower limb. This reconstructional technique was used in 11 patients undergoing metadiaphyseal resection of lower limb malignant bone tumors. All patients with Ewing's sarcoma and osteosarcoma had multimodal treatment according to the EURO-E.W.I.N.G 99 or COSS-96 protocol. Median FU was 63 months. None of the patients experienced local recurrence during FU. 2 patients died due to distant disease during FU. Full weight- bearing was permitted after a mean of 8 months. The median MSTS score was 87%. Complications occurred in five patients. None of the complications led to failure of the biological reconstruction or to amputation. Biological reconstruction of osseous defects is always desirable when possible and aims at a permanent solution. Good functional and durable results can be obtained by using BVFG for the reconstruction of metadiaphyseal defects of the femur and tibia. Radiotherapy in the multimodal setting increases the risk for graft or fixation failure.

The clinical outcomes of extracorporeal irradiated and re-implanted cemented autologous bone graft of femoral diaphysis after tumour resection

PURPOSE

We report the outcome of intercalary resection of the femoral diaphysis and extracorporeal irradiated autologous bone graft reconstruction, without the use of vascularized fibular graft.

METHODS

Six patients with Ewing sarcoma of the mid-shaft femur who were treated by limb sparing tumour resection and reconstruction with extracorporeal irradiated autologous bone graft with intramedullary cement between 2002 and 2010 were studied.

RESULTS

Mean age at the time of surgery was ten years (range, four-23). The length of resected femoral bone averaged 23 cm (15-32 cm). The ratio of bone resection length to total femoral length averaged 60 % (56-66 %). The patients had been followed up for between 16 and 79 months (mean, 41 months) at the time of the study. There was no infection nor fracture in this series. Primary union of the distal and proximal osteotomy sites was achieved in three patients. Delayed union of the proximal osteotomy site occurred in one patient that was successfully treated with iliac crest bone grafting. One patient developed non-union at the distal osteotomy site which failed to heal with bone grafting and was therefore converted to endoprosthetic replacement, and another patient was converted to rotationplasty at five months post-surgery because of contaminated margins. Function was excellent in all patients with surviving re-implanted bone. Local recurrence arose in one patient.

CONCLUSION

Our experience suggests that cement augmentation of extracorporeal irradiated and re-implanted bone autografts offer a useful method of reconstructing large femoral diaphyseal bone defects after excision of primary malignant bone tumours.