Original ArticleOptimal bone biopsy route to the proximal femur evaluated by computed tomography-based finite element modeling
Introduction
The proximal femur is one of the most common anatomical locations of cystic bone lesions such as aneurysmal bone cysts (ABC) and unicameral bone cysts (UBC) [1]. Generally, surgical intervention has been advocated for large cystic bone lesions to prevent fractures and subsequent complications of skeletal deformities, especially in the weight-bearing long bones [2,3]. To determine a precise diagnosis and treatment strategy for these cystic bone lesions, histopathological analysis is necessary. To get the specimen of the lesion, a needle biopsy using a bone marrow needle size 8–11G (outer diameter 3–4 mm) or an open biopsy that creates a bone hole of about 1–1.5 cm in the cortical bone is performed [4]. Furthermore, for benign cystic lesions such as ABC and UBC, a biopsy technique known as a “curopsy” or a percutaneous limited curettage at the time of biopsy is widely performed as a treatment [5,6].
A bone biopsy is an invasive examination, and its complications are concerning. A fracture at the biopsy site is a rare but severe complication of bone biopsy [4, 7, 8]. A diaphysis of the long bone has a relatively simple structure, and it is well-documented that the sizes and shapes of cortical defects present risks for pathological fractures [9,10]. For femoral trochanteric lesions, a bone biopsy performed from the inferolateral side of the hip joint is recommended [11,12]. However, the shapes of the trabecular bone and cortical bone with femoral trochanteric lesions are complicated; therefore, the relationship between the site of the bone biopsy or the size of the bone biopsy specimen and the risk of fracture after bone biopsy has not been well-studied.
Finite element (FE) modeling is a computational technique that can be used to solve biomedical engineering problems; it is based on the theories of continuum mechanics. Computed tomography (CT)-based FE modeling images estimate the elastic modulus and compressive strength by considering the distribution of bone mineral density on CT and enables fracture prediction for each patient [13,14].
This study investigated the inference of bone strength according to CT-FE modeling in relation to bone biopsy of the femoral trochanteric lesion and determined the optimum bone biopsy level and maximum allowable bone biopsy specimen size.
Section snippets
Materials and methods
This retrospective study was approved by the Institutional Review Board of our hospital and complied with the Health Insurance Portability and Accountability Act. It was exempt from obtaining individual informed consent.
Results
The mean fracture load of the femur before creating the bone defect was 5.05 ± 0.858 kN. For all specimens, the FE modeling analysis showed that the solid and shell elements undergoing compressive failure were in the femoral neck region. For bone defects with a diameter of 10 mm, there was a tendency for the mean fracture load to decrease by 6%–8%, on average, from level 3 to level 5; however, there was no significant difference in the fracture loads of each femur before biopsy (control).
For
Discussion
In this study, when the bone biopsy was performed from the lateral cortex of the femur to level 4 and level 5 (lesser trochanter level) with a diameter of 15 mm and from level 3 to level 5 (from the level of the vastus lateralis origin to the lesser trochanter level) with a diameter of 20 mm, bone strength significantly decreased.
A diaphysis of the long bone has a relatively simple structure and has been well-documented. It has been reported that bone metastasis to the diaphysis increases the
Conclusions
The effect of a bone biopsy on the lateral side of the proximal femur on bone strength was analyzed using CT-FE modeling. A bone biopsy of a cortical defect ≥15 mm in diameter from the level of the vastus lateralis origin and distal from the vastus lateralis origin reduced the bone strength of the femur. A bone biopsy of the lower end of the greater trochanter can avoid contamination of the bursa and minimize the effect on bone strength.
Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Declaration of competing interest
The authors have nothing to declare for this study.
References (28)
- et al.
Bone and soft tissue tumors of hip and pelvis
Eur J Radiol
(2012 Dec) - et al.
Extended curettage and adjuvant therapy for benign tumors of the talus
Foot (Edinb)
(2015 Jun) - et al.
Iliac fracture after a bone marrow biopsy
PMR
(2011 Dec) - et al.
Prediction of pathological fracture of the femoral shaft with an osteolytic lesion using a computed tomography-based nonlinear three-dimensional finite element method
J Orthop Sci
(2016 Jul) - et al.
Finite element analysis and CT-based structural rigidity analysis to assess failure load in bones with simulated lytic defects
Bone
(2014 Jan) - et al.
European Society of Biomechanics S.M. Perren Award 2014: safety factor of the proximal femur during gait: a population-based finite element study
J Biomech
(2014 Nov) - et al.
Biomechanical model of a high risk impending pathologic fracture of the femur: lesion creation based on clinically implemented scoring systems
Clin Biomech (Bristol, Avon)
(2013 Apr) - et al.
Male-female differences in the association between incident hip fracture and proximal femoral strength: a finite element analysis study
Bone
(2011 Jun) - et al.
Locking plate and fibular strut-graft augmentation in the reconstruction of unicameral bone cyst of proximal femur in the paediatric population
Int Orthop
(2018 Jan) - et al.
Current concepts in the biopsy of musculoskeletal tumors: AAOS exhibit selection
J Bone Joint Surg Am
(2015 Jan)