Keywords
fractures, spontaneous - polymethyl methacrylate - bone neoplasms - bone cements
Introduction
Advances in chemotherapy and radiotherapy treatment have increased the life expectancy of cancer patients, making them more susceptible to metastatic presentation.[1]
Pathological fractures occur in between 11 and 29% of metastatic bone lesions.[2]
[3]
[4]
[5] Surgical treatment allows for improved functional capacity, greater emotional acceptance, and care, as well as pain relief; therefore, early treatment provides a far better quality of life.[6]
Benign lesions such as simple and aneurysmal bone cyst, fibrous dysplasia, giant cell tumors, and Paget disease present an increased risk of fracture, especially in the proximal portion of long bones.[7]
[8]
[9]
Among the surgical methods, the foremost used is the intramedullary nail (IMN), due to its biomechanical properties[5]
[10]
[11]
[12]
[13] and greater stability in the face of disease progression, where the stabilization of lesions with the utilization of plates and screws may fail and define the survival of the patient.
The IMN can be introduced through the open or percutaneous technique; therefore, the use of bone cement allows for greater stability and pain control.[14]
[15]
[16] The association of bone cement has already been shown to be efficient in the oncological treatment of the spine and flat bones.[17]
The present study aimed to evaluate the results of the treatment of pathological lesions in long bones with the use of IMN associated or not with polymethylmethacrylate (PMMA).
Materials and methods
Between January 2012 and September 2017, 38 patients with 42 pathological injuries were treated, meeting the objectives of this research, with fractures or bone injuries on the verge of a fracture according to the criteria of Mirels, who underwent surgical procedure, being divided into two groups.
The inclusion criteria were: long bone neoplasm (primary or secondary), meeting the criteria of Mirels with surgical indication, pathological fractures in long bones, intramedullary osteosynthesis associated or not with PMMA, absence of previous treatment of the lesion, acceptance of the written informed consent form (WICF).
The exclusion criteria were: previous fracture in the affected limb, non-intramedullary osteosynthesis, a previous infectious process in the affected limb, non-acceptance of the WICF.
Group 1, with 16 patients, received treatment with IMN. For Group 2, with 22 patients, the treatment was associated with PMMA. The surgical technique had similar surgical steps. After placing the nail and drilling the locking holes close to the insertion of the nail, the material was removed, and a hole was drilled in the metadiaphyseal region opposite to the entrance of the nail. The objective was to reduce intramedullary pressure during cementation and insertion of the intramedullary cement through the nail entry point, with continuous aspiration through the drilling point. Before the complete hardening of the cement, the nail is replaced and locked.
Among the patients allocated to Group 1, 11 females and 5 males, the primary disease is described in [Table 1]. The lesion site in eight cases was the proximal femur, five cases with involvement of the diaphyseal humerus, two cases in the diaphyseal portion of the femur, and on case in the distal femur ([Table 1]).
Table 1
|
Control
|
Intramedullary nail + PMMA
|
|
Gender (F:M)
|
11:5
|
15:7
|
|
Primary Injury
|
|
|
|
Breast
|
6
|
8
|
|
Multiple myeloma
|
2
|
2
|
|
Prostate
|
1
|
4
|
|
Uterine
|
0
|
2
|
|
Pulmonary
|
0
|
1
|
|
Melanoma
|
0
|
1
|
|
Colon
|
1
|
0
|
|
COA
|
1
|
0
|
|
Lymphoma
|
1
|
0
|
|
Hepatic
|
1
|
0
|
|
Renal
|
1
|
2
|
|
Fibrous dysplasia
|
1
|
0
|
|
Fracture secondary to osteochondroma resection
|
1
|
0
|
|
Hyperparathyroidism
|
0
|
1
|
|
Fracture secondary to radiation
|
0
|
1
|
In Group 2 patients, 15 females and 7 males, the primary disease is described in [Table 1]. The lesion site in 10 cases was the proximal femur, in 10 cases the diaphyseal humerus, 4 cases in the diaphyseal portion of the femur, 1 case in the distal femur, and 1 fracture of the diaphyseal tibia. In this group, there was one patient with a bilateral humeral fracture, one patient with bilateral transtrochanteric injury, and one patient with a bilateral femoral diaphyseal fracture and humeral diaphyseal fracture ([Table 1]).
The mean follow-up time for the patients in Group 1 was 11.7 months (between 0 and 63 months), and in Group 2 it was 8.4 months (between 0 and 30 months). The functional assessment of the patients was performed through the analysis of the Musculoskeletal Tumor Society (MSTS) score. The postoperative radiographic assessments were carried out in order to verify the union of the fractures.
Results
A total of 38 patients, with a mean age of 59.24 years (between 14 and 85 years old), 26 females and 12 males, met the inclusion criteria. One patient had a bilateral femur fracture and a unilateral humerus fracture, 1 had a bilateral proximal femoral injury, and 1 had a bilateral humerus fracture, comprising 42 treated injuries.
The radiographic evaluation showed adequate alignment of the fractures and, in cases with a follow-up >1 year, no case of pseudarthrosis was evidenced by the radiographs. One patient with a fracture within the proximal femur had apparent cement leakage, but this patient did not wish to undergo to a replacement treatment, as she had sporadic pain.
The mean age in the control group was 51.5 years old (between 14 and 85 years old), whereas in the group treated with PMMA associated with IMN the mean age was 64.8 years old (between 27 and 84 years old). The mean follow-up time in the control group was 11.7 months (between 0 and 63 months), and in the PMMA-associated IMN group, it was 8.4 months (between 0 and 30 months). There was no statistical difference between ages in the groups (p = 0.05), as well as no statistical difference in the follow-up (p = 0.48) ([Table 2]).
Table 2
|
Control
|
Intramedullary nail + PMMA
|
|
|
Age (years old)
|
51.5
|
64.8
|
p = 0.05
|
|
Follow-up (months)
|
11.7
|
8.4
|
p = 0.48
|
The functional assessment of patients using the MSTS questionnaire showed the superiority of the group that received the treatment linked to PMMA, with statistical significance (p = 0.049). The control group had an average score of 16.375 out of a maximum of 30 points, while the group with the PMMA association had an average score of 22.36 points ([Fig. 1]).
Fig. 1 MSTS rating scale for functional evaluation.
In a comparative evaluation with new segmentation, this difference was not observed when we compared only the patients with injuries and treatments in the upper limbs, with a mean score of 20 (n = 5) in the MSTS questionnaire of patients treated with surgical synthesis material, and a score of 23.125 (n = 8) when associated with PMMA (p = 0.60). However, when this assessment was carried out comparing patients with injuries in the lower limbs, the control group (n = 10) had an average score of 13.6, and the group with PMMA association (n = 13) had an average score of 21.46, with statistical significance (p = 0.036).
The comparison between the affected upper and lower limbs shows no difference within the group in the comparison between the control group and the group associated with PMMA. The patients in the control group with injury in the upper limbs, with a mean score of 20 (n = 5) versus patients with injuries in the lower limbs of the control group (n = 10), with a mean score of 13.6 (p = 0.21). In a comparison linked to PMMA, however, no statistical difference was observed: patients with injuries in the upper limbs treated with IMN + PMMA had a score of 23.125 (n = 8) versus the group of patients with injuries in the lower limbs (n = 13), with a mean score of 21.46 (p = 0.69).
Among the complications related to surgical treatment, we did not observe any statistical difference between the series. In the control group, there were three deaths (one after pulmonary thromboembolism [PE]), one deep surgical site infection, one superficial infection, and one case of decompensated heart failure. In the treatment group with association with PMMA, two deaths were observed (one case after PTE associated with stroke, and one after acute renal failure in a polytrauma patient), two cases of bone cement extravasation (one of these cases was examined in the initial surgery, with the removal of extravasated cement), one case of hypokalemia, and two of delirium ([Figs. 2] and [3]).
Fig. 2 Metastatic breast cancer lesion in the proximal femur in a 61-year-old patient with transtrochanteric fracture and impending contralateral fracture. The distal locking screw was not necessary due to stabilization with bone cement.
Fig. 3 Pathological fracture of the left humerus. Primary lung adenocarcinoma (A) pathological fracture; (B) fixation with nail and cement; (C) bone union 15 weeks.
Discussion
The goal of treating pathological lesions is early mobilization, pain relief, and functional recovery as quickly as possible.[18] The Mirels score proved to be an important tool to identify the precise timing of prophylactic fixation of the tumor lesions.[19]
[20]
[21]
Conservative treatment showed the worst results, with higher morbimortality; thus, surgical treatment is the standard treatment for pathological fractures.[22] Osteosynthesis showed a lower rate of complications when compared with an endoprosthesis, as it allows immediate support.[23] The use of long nails is the most chosen and indicated method, as it prevents future injuries as the disease progresses. The milling procedure of the medullary canal showed biomechanical advantages. The possibility of tumor cell dissemination has not been demonstrated.[24]
[25]
[26]
[27]
The treatment with association with PMMA and IMN has advantages over the standard treatment only with the use of the implant. As the cement occupies the spinal space, bleeding from the lesion is reduced. The cement provides greater mechanical stability to the compound, reducing adjacent bone destruction, and, consequently, pain.[17]
[28] Reports show that cement would lead to volume reduction and tumor necrosis caused by thermal injury, as well as to reduced blood supply to the tumor.[29]
[30]
Conclusion
Surgical treatment for long bone injuries, especially in palliative cases, aims at rapid pain control and functional recovery. Thus, the association with the percutaneous method of fixation of long bone fractures, with the use of an intramedullary nail associated with cementation with PMMA, proved to be an efficient technique. It presented complication rates similar to those of the traditional method and better functional results, allowing the patient to recover quickly. These results are more prominent in patients with lower limb involvement when compared with patients with upper limb injuries.
