The aim of our study was to evaluate the outcomes of the treatment of malignant bone tumors by replantation of the extracorporeally irradiated bone segments, to establish the rate of successful bone healing and to evaluate the role of (non-) vascularized fibular augmentation of the reconstruction. Additional factors, which might influence the result were also analyzed.
This retrospective analysis was performed based on our tumor database and current follow-up data. We identified 21 consecutive patients with resection, irradiation and replantation of the tumor bone segment, operated between 1999 and 2015. The same surgeon treated all patients. The indications for this procedure were the following:
- Indication for wide resection of the tumor
- Localization of the tumor in the metaphysis or diaphysis of a long bone
- Sufficient residual bone stability
The diagnosis of the tumor was ascertained by an incision or core-needle biopsy based on radiological imaging (MRI, CT- and/or PET-CT scan). Primary bone tumors as well as metastases of other tumor entities were included. Systemic therapy was applied in some patients depending on the requirements of the underlying tumor condition.
There were 9 female and 12 male patients. The range of the age at the time of operative treatment was between 10 and 83 years (median age 36.4 years), 3 of them younger than 18 years. These 21 patients underwent 22 primary operations. One patient had a simultaneous partial femur and tibia resection. No patient was lost to follow-up. The details to the patients are displayed in Table 1.
Table 1
Patient characteristics (sex: m = male, f = female)
Pat ID
|
Age
|
Sex
|
Tumor Entity
|
Location
|
Fibula-augmentation
|
Type of complication
|
Number of revisions
|
Bony union achieved
|
1
|
10
|
m
|
Ewing Sarcoma
|
tibia
|
yes
|
infection
|
5
|
yes
|
2
|
11
|
m
|
Osteosarcoma
|
femur
|
yes
|
|
0
|
yes
|
3
|
66
|
f
|
Osteosarcoma
|
femur
|
no
|
pseudarthrosis
|
2
|
yes
|
4
|
57
|
m
|
Leiomyosar-coma
|
tibia
|
yes
|
|
0
|
yes
|
5
|
26
|
f
|
Ewing Sarcoma
|
femur
|
yes
|
|
0
|
yes
|
6
|
13
|
m
|
Osteosarcoma
|
femur
|
yes
|
pseudarthrosis
|
4
|
Prosthesis
|
7
|
58
|
m
|
HCC-Metastasis
|
femur
|
no
|
infection
|
2
|
yes
|
8
|
27
|
m
|
Ewing Sarcoma
|
femur
|
yes
|
|
0
|
yes
|
9
|
37
|
f
|
Osteosarcoma
|
femur
|
yes
|
pseudarthrosis
|
8
|
yes
|
10
|
79
|
f
|
RCC-Metastasis
|
tibia
|
no
|
hematoma
|
1
|
yes
|
11
|
32
|
m
|
Ewing Sarcoma
|
calcaneus
|
yes
|
hematoma
|
1
|
pseudarthrosis
|
12
|
29
|
m
|
Ewing Sarcoma
|
calcaneus
|
no
|
|
0
|
not possible (total bone)
|
13
|
20
|
f
|
Ewing Sarcoma
|
tibia
|
yes
|
wound healing
|
2
|
yes
|
14
|
73
|
f
|
RCC-Metastasis
|
femur
|
yes
|
|
0
|
yes
|
|
|
|
RCC-Metastasis
|
tibia
|
yes
|
infection
|
3
|
yes
|
15
|
31
|
m
|
Chondrosar-coma
|
tibia
|
no
|
|
0
|
yes
|
16
|
36
|
f
|
Ewing Sarcoma
|
calcaneus
|
no
|
wound healing
|
2
|
yes
|
17
|
49
|
m
|
RCC-Metastasis
|
femur
|
yes
|
|
0
|
yes
|
18
|
68
|
m
|
Myxofibrosar-coma
|
femur
|
yes
|
pseudarthrosis
|
1
|
yes
|
19
|
83
|
m
|
RCC-Metastasis
|
femur
|
no
|
pseudarthrosis
|
1
|
yes
|
20
|
62
|
m
|
Osteosarcoma
|
tibia
|
yes
|
|
0
|
yes
|
21
|
12
|
f
|
Ewing Sarcoma
|
femur
|
yes
|
pseudarthrosis
|
1
|
pseudarthrosis
|
For sterilization we used high-dose irradiation in all but the first patient, where thermal sterilization in an autoclave was used.
In the case of fibular augmentation, harvesting the graft was the first step of surgery. A wide resection of the tumor was subsequently performed. The explanted tumor-bearing bone segment was packed into a double sterile bag and transported to the radiation oncology department. To minimize any build-up effect and to keep radiation time short, the bag was wrapped with flab material and placed beneath the linear accelerator with the lowest possible distance to the accelerator head, usually on a tray in the accessory slot. A dose of 300 Gy using an opposing field technique was applied in a single fraction. After radiation, the bone (fragment) was immediately returned to the operation room.
In the next step, the irradiated bone was prepared for replantation, the soft tissue parts were resected as necessary (Fig. 1) followed by replantation and osteosynthesis. In 15 patients, an augmentation with a fibular graft was used. In 8 of these 15 cases, we used a vascularized fibula or performed a pedicled fibular interposition. The decision which method (vascularized/non-vascularized) fibula was used, depended primarily on the location. If a fibular transposition into a tibial defect was possible, we used a pediculated vascularized graft. In the first cases of femoral defects, we used free vascularized fibula grafts. Later, due to good reported experiences with non-vascularized fibula graft in literature [5], we changed our strategy and used non-vascularized grafts. The conventional radiographic controls were performed 6 weeks, 3, 6, 9 and 12 months after the surgery and then as required. The local tumor follow-up was done preferably by means of additional MRI. The definition of bony union was assessed by an experienced musculoskeletal radiologist based on the conventional radiographs obtained at follow-up (Fig. 2).
Significance analysis was performed using the Log-Rank test or the Chi-Square test, defining a 95% confidence interval. The univariate analysis (Cox proportional-hazards regression) was used for the evaluation of the influence of the distance of bone resection and of the reconnection of fibular vessels on the pseudarthrosis rate. The level of significance was set at less than 0.05. The data analysis software used was IBM® SPSS® Statistics 25. The institutional ethics committee approved this study.