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Fulltext Inertial Sensor-Based Instrumented Cane for Real-Time Walking Cane Kinematics Estimation

Fernandez IG, Ahmad SA, Wada C

Sensors (Basel), 2020 Aug 19;20(17).
PMID: 32825029 DOI: 10.3390/s20174675

Falls are among the main causes of injuries in elderly individuals. Balance and mobility impairment are major indicators of fall risk in this group. The objective of this research was to develop a fall risk feedback system that operates in real time using an inertial sensor-based instrumented cane. Based on inertial sensor data, the proposed system estimates the kinematics (contact phase and orientation) of the cane. First, the contact phase of the cane was estimated by a convolutional neural network. Next, various algorithms for the cane orientation estimation were compared and validated using an optical motion capture system. The proposed cane contact phase prediction model achieved higher accuracy than the previous models. In the cane orientation estimation, the Madgwick filter yielded the best results overall. Finally, the proposed system was able to estimate both the contact phase and orientation in real time in a single-board computer.

Matched MeSH terms: Biomechanical Phenomena
Effects of toe-out and toe-in gait with varying walking speeds on knee joint mechanics and lower limb energetics

Khan SS, Khan SJ, Usman J

Gait Posture, 2017 03;53:185-192.
PMID: 28189095 DOI: 10.1016/j.gaitpost.2017.01.022

Toe-out/-in gait has been prescribed in reducing knee joint load to medial knee osteoarthritis patients. This study focused on the effects of toe-out/-in at different walking speeds on first peak knee adduction moment (fKAM), second peak KAM (sKAM), knee adduction angular impulse (KAAI), net mechanical work by lower limb as well as joint-level contribution to the total limb work during level walking. Gait analysis of 20 healthy young adults was done walking at pre-defined normal (1.18m/s), slow (0.85m/s) and fast (1.43m/s) walking speeds with straight-toe (natural), toe-out (15°>natural) and toe-in (15°

Matched MeSH terms: Biomechanical Phenomena
The use of sonication treatment to decellularize aortic tissues for preparation of bioscaffolds

Azhim A, Syazwani N, Morimoto Y, Furukawa KS, Ushida T

J Biomater Appl, 2014 Jul;29(1):130-41.
PMID: 24384523 DOI: 10.1177/0885328213517579

A novel decellularization method using sonication treatment is described. Sonication treatment is the combination of physical and chemical agents. These methods will disrupt cell membrane and release cell contents to external environments. The cell removal was facilitated by subsequent rinsing of sodium dodecyl sulfate detergents. Sonication treatment is used in the preparation of complete decellularized bioscaffolds. The aim of this study is to confirm the usefulness of sonication treatment for preparation of biological scaffolds. In this study, samples of aortic tissues are decellularized by sonication treatment at frequency of 170 kHz in 0.1% and 2% sodium dodecyl sulfate detergents for 10-h treatment time. The relation between decellularization and sonication parameters such as dissolved oxygen concentration, conductivity, and pH is investigated. Histological analysis and biomechanical testing is performed to evaluate cell removal efficiency as well as changes in biomechanical properties. Minimal inflammation response elicit by bioscaffolds is confirmed by xenogeneic implantation and immunohistochemistry. Sonication treatment is able to produce complete decellularized tissue suggesting that these treatments could be applied widely as one of the decellularization method.

Matched MeSH terms: Biomechanical Phenomena
A fibril-based structural constitutive theory reveals the dominant role of network characteristics on the mechanical behavior of fibroblast-compacted collagen gels

Feng Z, Ishiguro Y, Fujita K, Kosawada T, Nakamura T, Sato D, et al.

Biomaterials, 2015 Oct;67:365-81.
PMID: 26247391 DOI: 10.1016/j.biomaterials.2015.07.038

In this paper, we present a general, fibril-based structural constitutive theory which accounts for three material aspects of crosslinked filamentous materials: the single fibrillar force response, the fibrillar network model, and the effects of alterations to the fibrillar network. In the case of the single fibrillar response, we develop a formula that covers the entropic and enthalpic deformation regions, and introduce the relaxation phase to explain the observed force decay after crosslink breakage. For the filamentous network model, we characterize the constituent element of the fibrillar network in terms its end-to-end distance vector and its contour length, then decompose the vector orientation into an isotropic random term and a specific alignment, paving the way for an expanded formalism from principal deformation to general 3D deformation; and, more important, we define a critical core quantity over which macroscale mechanical characteristics can be integrated: the ratio of the initial end-to-end distance to the contour length (and its probability function). For network alterations, we quantitatively treat changes in constituent elements and relate these changes to the alteration of network characteristics. Singular in its physical rigor and clarity, this constitutive theory can reproduce and predict a wide range of nonlinear mechanical behavior in materials composed of a crosslinked filamentous network, including: stress relaxation (with dual relaxation coefficients as typically observed in soft tissues); hysteresis with decreasing maximum stress under serial cyclic loading; strain-stiffening under uniaxial tension; the rupture point of the structure as a whole; various effects of biaxial tensile loading; strain-stiffening under simple shearing; the so-called "negative normal stress" phenomenon; and enthalpic elastic behaviors of the constituent element. Applied to compacted collagen gels, the theory demonstrates that collagen fibrils behave as enthalpic elasticas with linear elasticity within the gels, and that the macroscale nonlinearity of the gels originates from the curved fibrillar network. Meanwhile, the underlying factors that determine the mechanical properties of the gels are clarified. Finally, the implications of this study on the enhancement of the mechanical properties of compacted collagen gels and on the cellular mechanics with this model tissue are discussed.

Matched MeSH terms: Biomechanical Phenomena/drug effects
The effect of dialysis environment on the mechanical behaviour of hollow polymeric fibers

Konduk BA, Ucisik AH

Med J Malaysia, 2004 May;59 Suppl B:53-4.
PMID: 15468815

The effect of hemodialysis on the mechanical behavior of a cellulosic Hemophane ME-IOH and one Polysulfone type hollow fibers was investigated. Mechanical tests showed that the deformation of polysulfone type of hollow fibers is entirely different than that of the other dialyser for the samples used and unused in hemodialysis. All the samples exposed to the dialysis showed decreased in ductility. Fracture surface studies proved that there was some alignment on the fracture surface. XRD and DSC experiments revealed structural changes had occurred.

Matched MeSH terms: Biomechanical Phenomena
Kinematic alignment is a possible alternative to mechanical alignment in total knee arthroplasty

Lee YS, Howell SM, Won YY, Lee OS, Lee SH, Vahedi H, et al.

Knee Surg Sports Traumatol Arthrosc, 2017 Nov;25(11):3467-3479.
PMID: 28439636 DOI: 10.1007/s00167-017-4558-y

PURPOSE: A systematic review was conducted to answer the following questions: (1) Does kinematically aligned (KA) total knee arthroplasty (TKA) achieve clinical outcomes comparable to those of mechanically aligned (MA) TKA? (2) How do the limb, knee, and component alignments differ between KA and MA TKA? (3) How is joint line orientation angle (JLOA) changed from the native knee in KA TKA compared to that in MA TKA?
METHODS: Nine full-text articles in English that reported the clinical and radiological outcomes of KA TKA were included. Five studies had a control group of patients who underwent MA TKA. Data on patient demographics, clinical scores, and radiological results were extracted. There were two level I, one level II, three level III, and three level IV studies. Six of the nine studies used patient-specific instrumentation, one study used computer navigation, and two studies used manual instrumentation.
RESULTS: The clinical outcomes of KA TKA were comparable or superior to those of MA TKA with a minimum 2-year follow-up. Limb and knee alignment in KA TKA was similar to those in MA TKA, and component alignment showed slightly more varus in the tibial component and slightly more valgus in the femoral component. The JLOA in KA TKA was relatively parallel to the floor compared to that in the native knee and not oblique (medial side up and lateral side down) compared to that in MA TKA. The implant survivorship and complication rate of the KA TKA were similar to those of the MA TKA.
CONCLUSION: Similar or better clinical outcomes were produced by using a KA TKA at early-term follow-up and the component alignment differed from that of MA TKA. KA TKA seemed to restore function without catastrophic failure regardless of the alignment category up to midterm follow-up. The JLOA in KA TKA was relatively parallel to the floor similar to the native knee compared to that in MA TKA. The present review of nine published studies suggests that relatively new kinematic alignment is an acceptable and alternative alignment to mechanical alignment, which is better understood. Further validation of these findings requires more randomized clinical trials with longer follow-up.
LEVEL OF EVIDENCE: Level II.

Matched MeSH terms: Biomechanical Phenomena
Biomechanical investigation on the influence of the regional material degeneration of an intervertebral disc in a lower lumbar spinal unit: A finite element study

Masni-Azian, Tanaka M

Comput Biol Med, 2018 07 01;98:26-38.
PMID: 29758454 DOI: 10.1016/j.compbiomed.2018.05.010

Intervertebral disc degeneration involves changes in its material properties that affect the mechanical functions of the spinal system. However, the alteration of the biomechanics of a spinal segment through specific material degradation in a specific region is poorly understood. In this study, the influence of the constitutive material degeneration of disc tissues on the mechanics of a lower lumbar spinal unit was examined using a three-dimensional nonlinear finite element model of the L4-L5 functional spinal unit. Different grades of disc degeneration were simulated by introducing a degeneration factor to the corresponding material properties to represent fibrous nucleus, increased fibre and ground substance laxity, increased fibre stiffness and total annular fracture along posterior and posterolateral regions. The model was loaded with an axial compression of 500 N and pure moments of up to 10 Nm to simulate extension, flexion, lateral bending and axial rotation. To validate the model, the spinal motion and intradiscal pressure of healthy and degenerated discs with existing in vitro data were compared. The disc with a fibrous nucleus and the presence of intradiscal pressure increase the spinal instability during flexion and axial rotation, and the absence of intradiscal pressure increases the spinal instability in all directions. Bulging displacement and shear strains in the disc with total fracture and ground substance laxity are high in all of the loading cases. Our study could provide useful information to enhance our understanding of the influence of each constitutive component of the intervertebral disc on the mechanics of the spinal segment.

Matched MeSH terms: Biomechanical Phenomena/physiology*
Statistical factorial analysis approach for parameter calibration on material nonlinearity of intervertebral disc finite element model

Masni-Azian, Tanaka M

Comput Methods Biomech Biomed Engin, 2017 Aug;20(10):1066-1076.
PMID: 28532164 DOI: 10.1080/10255842.2017.1331345

In the biomechanics field, material parameters calibration is significant for finite element (FE) model to ensure a legit estimation of biomechanical response. Determining an appropriate combination of calibration factors is challenging as each constitutive component responds differently. This study proposes a statistical factorial analysis approach using L16(4(5)) orthogonal array to evaluate material nonlinearity and applicable calibration factor of the intervertebral disc FE model in pure moment. The calibrated model exhibits improved agreement to the experimental findings for all directions. Appropriate combination of calibration parameter reduces the estimation gap to the experimental findings, ensuring agreeable biomechanical responses.

Matched MeSH terms: Biomechanical Phenomena
Fulltext Osteoarthritis and falls in the older person

Ng CT, Tan MP

Age Ageing, 2013 Sep;42(5):561-6.
PMID: 23864423 DOI: 10.1093/ageing/aft070

Osteoarthritis and falls are common conditions affecting older individuals which are associated with disability and escalating health expenditure. It has been widely assumed that osteoarthritis is an established risk factor for falls in older people. The relationship between osteoarthritis and falls has, quite surprisingly, not been adequately elucidated, and published reports have been conflicting. Our review of the existing literature has found limited evidence supporting the current assumption that the presence of osteoarthritis is associated with increased risk of falls with suggestions that osteoarthritis may actually be protective against falls related fractures. In addition, joint arthroplasty appears to increase the risk of falls in individuals with osteoarthritis.

Matched MeSH terms: Biomechanical Phenomena
Fulltext Ergonomic task analysis in electronics industries: some case studies

Tan GL

J Hum Ergol (Tokyo), 1996 Jun;25(1):49-62.
PMID: 9551132 DOI: 10.11183/jhe1972.25.38

The analyses of a few tasks were carried out in an electronics factory. The main objectives are to identify the ergonomic and biomechanical hazards of problem work tasks, to analyze each task systematically in order to evaluate the workers' exposures to the risk factors of force, posture pressure and repetition and to make recommendations to reduce the risks and hazards. The methodology includes objective measures--detailed analysis by going through training manuals, job description and production records. Subjective measures include interviewing the operator and supervisors informally, the operators were also required to fill in a structured questionnaire. The paper concludes by making recommendations to reduce the ergonomic hazards by engineering solutions, redesign or administrative controls or the implementation of procedures.

Matched MeSH terms: Biomechanical Phenomena
Investigation on mechanical properties of contemporary metallic bone plates: towards the development of composite bone plates

Hoque ME, Zainal NH, Syarif J

Med J Malaysia, 2008 Jul;63 Suppl A:91-2.
PMID: 19024999

This study aims at investigating the mechanical properties of the contemporary metallic bone plates determining the effect of their length, width and thickness on the properties and compares with the composite bone plates. Three-points bending test was performed over the stainless steel plates of different length, width and thickness. The test results showed that different plates had different mechanical properties. However, the properties are still much higher than that of particular bones intended to be treated. Therefore, the reported findings strongly encourage developing composite bone plates with biocompatible polymers/fibers that would have modulated properties according to the requirements.

Matched MeSH terms: Biomechanical Phenomena
Effect of torsional loading on compressive fatigue behaviour of trabecular bone

Fatihhi SJ, Rabiatul AA, Harun MN, Kadir MR, Kamarul T, Syahrom A

J Mech Behav Biomed Mater, 2016 Feb;54:21-32.
PMID: 26410762 DOI: 10.1016/j.jmbbm.2015.09.006

The present study reports the effects of combined torsional and compressive cyclic loading on trabecular bone in order to mimic true physiological conditions and thereby provides improved data that represents clinical and real life conditions. However, only compressive behaviour is evaluated in most previous studies of bone mechanics. From the monotonic evaluation, it is observed that lower stress is needed for the onset of microcrack in the sample under torsional loading, compared to the stress needed in compression. Trabecular bone samples were subjected to a combination of torsion and compression fatigue at different stress levels during which they were compared to compressive axial fatigue. The stress levels were determined by considering the monotonic strength at 25-50% for both compressive and shear stresses. Significant decrease in fatigue lifetime is observed in between samples of pure compression fatigue and those with superpositioned torsional loading (p<0.05). The reduction in fatigue lifetime became more evident at a high torsional stress level. In this case, the failure of the sample is said to be 'torsional dominant'. Fatigue behaviour of bovine trabecular bone begins with plastic deformation, followed by strain accumulation and modulus reduction. As the strain rate increases, more energy dissipates and the sample finally failed. Further, the analysis of fractograph revealed something on the trabeculae by bending in sample with superpositioned torsional loading. In conclusion, torsional loading decreases the quality of the trabecular properties in terms of stiffness, life and structural integrity. It is hoped that results from this study will improve the understanding of the behaviour of trabecular bone under combined fatigue and help to develop future assessments of trabecular failure.

Matched MeSH terms: Biomechanical Phenomena
Fulltext Visual perception of kuda and sila service techniques in sepak takraw

Mohamad Razali Abdullah, Saidon Amri, Suppiah, Pathmanathan K.

Movement Health & Exercise, 2012;1(1):25-37.
MyJurnal

Two major types of services in sepak takraw are kuda and sila services. Even though both services are delivered at high speed, each is composed of different kinematic features. The purpose of the study was to determine the fundamental differences in perceptual strategies in
anticipating the kuda and sila services. The receiver of the game in sepak takraw makes decisions under severe time constraint in both spatial and temporal uncertainty. The study examined two groups of 12 players each; the experts and the novices. Perceptual displays in anticipation of the
kuda and sila services were prompted using video stimulations consisting of seven temporal occlusions t1 (240 milliseconds at pre-contact), t2 (160 milliseconds at pre-contact), t3 (80 milliseconds at pre-contact, t4 (0 millisecond at contact), t5 (80 milliseconds at post-contact), t6 (160
milliseconds at post-contact), and t7 (no occlusion). Significant differences amongst expert players in anticipating kuda and sila services were at t1 F (14, 180) = 2.37; p < 0.05], t2 F (14, 180) = 5.60; p < 0.05], t3 F (14, 180) = 3.81; p < 0.05] and t4 F (14, 180) = 2.00; p < 0.05]. Similar comparisons at t5, t6, and t7 did not yield any significant differences. In addition, there were significant differences amongst novice players in anticipating kuda and sila services at t2 F (14,
180) = 2.27; p < 0.05], t3 F (14, 180) = 1.94; p < 0.05], t4 F (14, 180) = 2.61; p < 0.05], and t5 F (14, 180) = 9.38; p < 0.05]. Overall findings revealed that expert players found it more difficult to anticipate kuda service compared to sila service at t1. Hence, the kuda service is more
difficult to anticipate than sila service. Participants of this study demonstrated a more effective visual perceptual strategy to counter attack a sila service than they would with a kuda service.

Matched MeSH terms: Biomechanical Phenomena
A systematic review of muscle activity assessment of the biceps brachii muscle using mechanomyography

Talib I, Sundaraj K, Lam CK, Sundaraj S

J Musculoskelet Neuronal Interact, 2018 12 01;18(4):446-462.
PMID: 30511949

This systematic review aims to categorically analyses the literature on the assessment of biceps brachii (BB) muscle activity through mechanomyography (MMG). The application of our search criteria to five different databases identified 319 studies. A critical review of the 48 finally selected records, revealed the diversity of protocols and parameters that are employed in MMG-based assessments of BB muscle activity. The observations were categorized into the following: muscle torque, fatigue, strength and physiology. The available information on the muscle contraction protocol, sensor(s), MMG signal parameters and obtained results were then tabulated based on these categories for further analysis. The review affirms that - 1) MMG is suitable for skeletal muscle activity assessment and can be employed potentially for further investigation of the BB muscle activity and condition (e.g., force, torque, fatigue, and contractile properties), 2) a majority of the records focused on static contractions of the BB, and the analysis of dynamic muscle contractions using MMG is thus a research gap, and 3) very few studies have focused on the analysis of BB muscle activity under externally stimulated contractions. Taken together, the findings of this review on BB activity assessment using MMG affirm the potential of MMG as an alternative tool.

Matched MeSH terms: Biomechanical Phenomena/physiology
Fulltext Intra-Rater Reliability and Minimal Detectable Change of Vertical Ground Reaction Force Measurement during Gait and Half-Squat Tasks on Healthy Male Adults

Fairus FZ, Joseph LH, Omar B, Ahmad J, Sulaiman R

Malays J Med Sci, 2016 Mar;23(2):21-7.
PMID: 27547111 MyJurnal

The understanding of vertical ground reaction force (VGRF) during walking and half-squatting is necessary and commonly utilised during the rehabilitation period. The purpose of this study was to establish measurement reproducibility of VGRF that reports the minimal detectable changes (MDC) during walking and half-squatting activity among healthy male adults.

Matched MeSH terms: Biomechanical Phenomena
Interface pressure profile analysis for patellar tendon-bearing socket and hydrostatic socket

Moo EK, Osman NA, Pingguan-Murphy B, Abas WA, Spence WD, Solomonidis SE

Acta Bioeng Biomech, 2009;11(4):37-43.
PMID: 20405814

Conventionally, patellar tendon-bearing (PTB) sockets, which need high dexterity of prosthetist, are widely used. Lack of chartered and experienced prosthetist has often led to painful experience of wearing prosthesis and this will in turn deter the patients to wear the prosthesis, which will further aggravate stump shrinkage. Thus, the hydrostatic socket which demands relatively lower level of fabricating skill is proposed to replace the PTB socket in order to produce the equivalent, if not better, quality of support to the amputee patients. Both sockets' pressure profiles are studied and compared using finite element analysis (FEA) software. Three-dimensional models of both sockets were developed using MIMICS software. The analysis results showed that hydrostatic socket did exhibit more uniform pressure profiles than that of PTB socket. PTB socket showed pressure concentration near the proximal brim of the socket and also at the distal fibula. It was also found that the pressure magnitude in hydrostatic socket is relatively lower than that of PTB socket.

Matched MeSH terms: Biomechanical Phenomena
Vitamin E exhibits bone anabolic actions in normal male rats

Shuid AN, Mehat Z, Mohamed N, Muhammad N, Soelaiman IN

J. Bone Miner. Metab., 2010 Mar;28(2):149-56.
PMID: 19779668 DOI: 10.1007/s00774-009-0122-2

Recently, vitamin E has been found to promote the bone structure of nicotine-treated rats well above their baseline values, thus suggesting that vitamin E may have some anabolic action. A bone anabolic agent acts by improving the bone structure leading to stronger bone. To assess the possible anabolic action vitamin E on bone, we supplemented alpha-tocopherol (ATF) or gamma-tocotrienol (GTT) at 60 mg/kg or vehicle [normal control (NC) group] for 4 months to normal male rats and measured their bone structure and biomechanical properties. Histomorphometric analysis revealed that vitamin E-supplemented rats have better trabecular volume, thickness, number, and separation than rats receiving vehicle only. For the first time we reported that GTT improves all the parameters of bone biomechanical strength, while ATF only improved some of the parameters compared to the NC group. Vitamin E supplementation, especially with the gamma isomer, improves bone structure, which contributed to stronger bone. Therefore, vitamin E has the potential to be used as an anabolic agent to treat osteoporosis or as bone supplements for young adults to prevent osteoporosis in later years.

Matched MeSH terms: Biomechanical Phenomena
Glycyrrhizic acid (GCA) as 11β-hydroxysteroid dehydrogenase inhibitor exerts protective effect against glucocorticoid-induced osteoporosis

Ramli ES, Suhaimi F, Asri SF, Ahmad F, Soelaiman IN

J. Bone Miner. Metab., 2013 May;31(3):262-73.
PMID: 23274351 DOI: 10.1007/s00774-012-0413-x

Rapid onset of bone loss is a frequent complication of systemic glucocorticoid therapy which may lead to fragility fractures. Glucocorticoid action in bone depends upon the activity of 11β-hydroxysteroid dehydrogenase type 1 enzyme (11β-HSD1). Regulations of 11β-HSD1 activity may protect the bone against bone loss due to excess glucocorticoids. Glycyrrhizic acid (GCA) is a potent inhibitor of 11β-HSD. Treatment with GCA led to significant reduction in bone resorption markers. In this study we determined the effect of GCA on 11β-HSD1 activity in bones of glucocorticoid-induced osteoporotic rats. Thirty-six male Sprague-Dawley rats (aged 3 months and weighing 250-300 g) were divided randomly into groups of ten. (1) G1, sham operated group; (2) G2, adrenalectomized rats administered with intramuscular dexamethasone 120 μg/kg/day and oral vehicle normal saline vehicle; and (3) G3, adrenalectomized rats administered with intramuscular dexamethasone 120 μg/kg/day and oral GCA 120 mg/kg/day The results showed that GCA reduced plasma corticosterone concentration. GCA also reduced serum concentration of the bone resorption marker, pyridinoline and induced 11β-HSD1 dehydrogenase activity in the bone. GCA improved bone structure, which contributed to stronger bone. Therefore, GCA has the potential to be used as an agent to protect the bone against glucocorticoid induced osteoporosis.

Matched MeSH terms: Biomechanical Phenomena/drug effects
Fulltext Effects of calcium supplements on fracture healing in a rat osteoporotic model

Shuid AN, Mohamad S, Mohamed N, Fadzilah FM, Mokhtar SA, Abdullah S, et al.

J Orthop Res, 2010 Dec;28(12):1651-6.
PMID: 20572125 DOI: 10.1002/jor.21180

Fracture healing is a complex process, which is further complicated if the bone is osteoporotic. Calcium is one of the important minerals in bone and has been found to prevent osteoporosis but its role in fracture healing of osteoporotic bone is still unclear. We carried out a study on the effects of calcium supplementation on the late phase healing of fractured osteoporotic bone using an ovariectomized rat model. Twenty-four female Sprague-Dawley rats were divided into three groups: sham-operated (SO), ovariectomized-control (OVXC), and ovariectomized + calcium supplements (Ca). The right femurs of all the rats were fractured at mid-epiphysis and a K-wire was inserted for internal fixation. After 2 months of treatment, the rats were sacrificed and the femora were dissected out for radiological and biomechanical assessment. As expected, osteoporosis resulted in impaired healing as shown by the poor radiological and biomechanical properties of the OVXC group. CT scans showed significantly lower callus volumes in the SO and Ca groups compared to the OVXC group. Radiological scoring of fracture healing and callus staging of the SO and Ca groups were better than the OVXC group. However, the biomechanical parameters of the Ca group were significantly lower than the SO group and similar to the OVXC group. Therefore, calcium supplements may appear to improve fracture healing of osteoporotic bone but failed to improve strength.

Matched MeSH terms: Biomechanical Phenomena
The effects of alpha-tocopherol supplementation on fracture healing in a postmenopausal osteoporotic rat model

Mohamad S, Shuid AN, Mohamed N, Fadzilah FM, Mokhtar SA, Abdullah S, et al.

Clinics (Sao Paulo), 2012 Sep;67(9):1077-85.
PMID: 23018307

OBJECTIVE: Osteoporosis increases the risk of bone fractures and may impair fracture healing. The aim of this study was to investigate whether alpha-tocopherol can improve the late-phase fracture healing of osteoporotic bones in ovariectomized rats.
METHOD: In total, 24 female Sprague-Dawley rats were divided into three groups. The first group was sham-operated, and the other two groups were ovariectomized. After two months, the right femora of the rats were fractured under anesthesia and internally repaired with K-wires. The sham-operated and ovariectomized control rat groups were administered olive oil (a vehicle), whereas 60 mg/kg of alpha-tocopherol was administered via oral gavage to the alpha-tocopherol group for six days per week over the course of 8 weeks. The rats were sacrificed, and the femora were dissected out. Computed tomography scans and X-rays were performed to assess fracture healing and callus staging, followed by the assessment of callus strengths through the biomechanical testing of the bones.
RESULTS: Significantly higher callus volume and callus staging were observed in the ovariectomized control group compared with the sham-operated and alpha-tocopherol groups. The ovariectomized control group also had significantly lower fracture healing scores than the sham-operated group. There were no differences between the alpha-tocopherol and sham-operated groups with respect to the above parameters. The healed femora of the ovariectomized control group demonstrated significantly lower load and strain parameters than the healed femora of the sham-operated group. Alpha-tocopherol supplementation was not able to restore these biomechanical properties.
CONCLUSION: Alpha-tocopherol supplementation appeared to promote bone fracture healing in osteoporotic rats but failed to restore the strength of the fractured bone.

Matched MeSH terms: Biomechanical Phenomena

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