DOES IN VIVO LIGAMENT FORCE PASS THROUGH LIGAMENT INSERTIONS?: A ROBOTIC STUDY

INTRODUCTION Post traumatic osteoarthritis (PTOA) is a subset of osteoarthritis that arises after traumatic joint injury. Approximately half of patients suffering from anterior cruciate ligament (ACL) injuries have been shown to progress towards PTOA within fifteen years[1]. One of the areas of research for PTOA is examining the biomechanical changes following an ACL injury. A recent study[2] examined the effects of ACL transection (ACLx) in an ovine model. In vivo stifle joint motions were recorded, and recreated in vitro using a novel robotic testing platform. Joint and tissue loads were simultaneously recorded during reproduction of in vivo joint motion[2]. This novel approach was shown to be able to reproduce in vivo motions within less than 0.1° and 0.1mm[2].   The main objective of the present study was to determine if in vivo ligament forces, obtained using the principle of superposition, pass through respective ligament insertional footprints. This study evaluated the accuracy of the measured ligament forces, as they should pass through their bony insertions. This accuracy was examined for medial and lateral collateral ligaments (MCL and LCL), and posterior cruciate ligament (PCL) in ACLx sheep.   METHODS Stifle joints from N=4 sheep that had been previously examined in ACLx kinematics studies were digitized using a coordinate measuring machine. The ligament insertional areas were thoroughly recreated in 3D space, along with the spatial position of the kinematic measurement device. Anatomic coordinate systems were defined on the femur and the tibia. These data were then exported to MATLAB scripts for further analysis. The ligament insertional areas were approximated as planes using least squares regression technique. The intersection of the ligament force vectors with the plane approximations were then calculated. The direction of a ligament force was deemed accurate if the distance between the calculated intersection and footprint centroid was within a determined threshold. A preliminary threshold was calculated as the maximum distance between the centroid and measured points of the footprint. RESULTS Analysis of the data indicated that the technique increases in accuracy for high ligament loads (Figure 1). That is to say as the ligament loads increase, the intersection-centroid distance is reduced. For lower ligament loads (mainly within the “toe” region of the ligament force-displacement behavior), however, the method requires further refinement. DISCUSSION AND CONCLUSIONS This study indicated that the method requires further refinement based on the limitations induced currently. Preliminary data shows that accuracy increases as ligament load magnitudes increase as well. Finding the intersections on plane approximations of the insertional footprints can lead to very large error when the planes approach a parallel state. In these states, a small angular change in force direction can cause a very large change in intersection-centroid distance. Each ligament and its insertions have different functions and geometries, and as such require separate limitations. Future studies would require modifications to the analysis method to account for the limitations involved with the current method

Measurement of Collimator Scatter Factor for Photon Fields Using Gafchromic EBT2 Film and Ion Chamber

Background and Objective: In radiotherapy, measurement of the output factor in the air is one of the input parameters for Implementation of treatment planning systems and beam modeling. The aim of this study is to design a mini-phantom and select the appropriate detector for measuring the output factor. Subjects and Methods: In-air output factor was measured for Siemens linear accelerator 6 MV energy and field sizes of 4, 6, 8, 10, 15, 2 cm irradiated by 200MU. Measurements were performed using a Gafchromic film EBT2 and 0.6 cc Farmer ion chamber and then the results were compared with Report of AAPM Therapy Physics Committee Task Group 74. For lateral electron equilibrium and electron contamination removal, two top of the water and Cerrobend were designed for film dosimetry and plexiglass buildup cap for Farmer chamber was applied. Results: The output factor increases with field size, and this increase in Cerrobend top is less than water top and Farmer dosimeter. In comparison between the results reported by TG74 and this study shows that film dosimetry with water top and Farmer chamber have 0.35 and 0.68 mean percentage differences with TG74 respectively and meanwhile the film dosimetry with Cerrobend top presents 1.48 mean percentage differences. Conclusion: EBT2 film with mini phantom made of water as a good alternative to ion chamber dosimeters known as a standard dosimeter especially the film can be used for a wider range of field size

LONG TERM IN VIVO KINEMATICS OF THE OVINE STIFLE JOINT FOLLOWING ANTERIOR CRUCIATE LIGAMENT TRANSECTION

INTRODUCTION Osteoarthritis (OA) is a degenerative joint disease involving the breakdown of articular cartilage, which is common after injury or with aging1. Following knee injury, sheep develop OA at a slightly accelerated rate compared to humans but with some similar patterns2. In an ovine knee injury model3,4, altered gait mechanics and degradation of the cartilage has been observed 20 weeks post anterior cruciate ligament (ACL) transection (Tx) surgery; however, potential alterations in gait at 40 weeks post ACL Tx surgery remain to be determined. Therefore, the objective of this study was to investigate the in vivo kinematics of the ovine stifle joint over time (20 weeks and 40 weeks) following ACL Tx. METHODS Force Plate Testing. Three skeletally mature 3 to 4-year-old female Suffolk-cross sheep (average weight 77.1kg) were led across an embedded force platform (Kistler Instrumente, Winterthur, Switzerland) until 20 hind limb hoof strikes were recorded at 1200 Hz. Peak hind limb vertical ground reaction force was determined prior to surgical plate implantation, and then serially prior to each kinematic data collection. Surgical Procedure. All sheep had a bone plate implanted onto each of the proximomedial aspect of the tibia and the distolateral aspect of the femur of their right hind limb, four weeks prior to kinematic testing. Kinematic Collection and Bone Digitization. On the day of kinematic testing, a stainless steel post was attached to each plate and an instrumented spatial linkage (ISL) mounted between them. The ISL consisted of six rotational encoders providing a measurement of position and orientation in six degrees of freedom (6-DOF) to its motion throughout gait. The in vivo kinematics of the stifle joint were measured while the sheep walked on a treadmill at 2 mph (0.89 m/s). Each sheep then underwent arthroscopic ACL Tx surgery on their right hind limb. The in vivo gait kinematics were measured again over time at 20 and 40 weeks post ACL Tx. Following kinematic testing at 40 weeks, the animals were euthanized. A coordinate measuring machine was used to measure anatomic landmarks on the bone with respect to the ISL in order to create an anatomically relevant coordinate system. Analysis. Data are presented as mean ± SD. RESULTS Figure 1: The 6-DOF in vivo gait kinematics of the ovine stifle joint, intact (black), 22 weeks post ACL Tx (red), and 40 weeks post ACL Tx (blue). DISCUSSION AND CONCLUSIONS These data indicate that the in vivo kinematics of the ovine stifle joint do change over time following ACL Tx. The kinematic changes appear to be more drastic after 22 weeks, and do not entirely return back to pre-injury mechanics in all rotations and translations after 40 weeks. As shown in Figure 1, the medial-lateral as well as posterior-anterior translation of the joint is progressively altered post ACL Tx over time. Rotationally, the internal-external kinematic curve at 22 weeks is dissimilar to the intact motion, however by 40 weeks a recovery towards the intact measurement is seen as the animal compensates for the injury. In the future, principal component analysis will be utilized to compare these gait changes. In conclusion, the transection of the ACL causes long-term changes in the in vivo kinematics of the joint. Alterations of the kinematics may result in degradation of cartilage due to abnormal loading of the joint and overall damage in the joint due to compensation of the instability post ACL Tx, which is a painful and destructive condition

Effect of Low-level Laser Therapy on Bone Defect Repair in Diabetic and Osteoporotic Rats using the Real-Time PCR Technique

Introduction: Bone formation is disturbed in type 1 diabetes followed by changes in the bone microstructure. The most important metabolic disorder in diabetes is osteoporosis, which is characterized by bone loss and bone structure degradation. This study aimed to determine the effect of lowpower laser on bone defect repair in the experimental model of diabetes and osteoporosis. Materials & Methods: A total of 30 fourmonth-old female Wistar rats weighing 190-220 g were selected and randomly divided into six groups, including 1: non-diabetic control (Co.), 2: non-diabetic laser (L.), 3: diabetic control (Co.D.), 4: diabetic laser (L.D.), 5: diabetic alendronate (A.D.), and 6: diabetic laser + alendronate (L.A.D.).Diabetes was induced in groups 3, 4, 5, and 6. All groups underwent ovariectomy and partial bone defect. In the laser group, a lowlevel laser (890nm, 80 Hz, 1/5J / cm 2) was radiated to 3 points at the defect location. Tibia bones were collected, and Real-time PCR was performed after a month. The data were analyzed using ANOVA. A p-value less than P<0.05 was considered statistically significant. Ethics code: 13237-91-1-1393- 10397 Findings: The t-test showed a significant decrease in tibia bone density in diabetic and osteoporotic rats, compared to the nondiabetic control group. Moreover, analysis of gene expression data (ANOVA, P<0.05) revealed a significant difference between the group of diabetic laser + alendronate and other groups in terms of Runx2 gene expression and Osteocalcin. Discussions & Conclusions: According to the findings, laser therapy combined with alendronate can accelerate the repair of partial bone defect in the experimental model of diabetes and osteoporosis. Keywords: Low-level laser, Osteoporosis, Partial bone defect, Real-time PCR, Type 1 diabete

Prenatal Diagnosis of Leukocyte Adhesion Deficiency Type-1 (Five Cases from Iran with Two New Mutations)

Leukocyte adhesion deficiency type-1(LAD-1) is one of the autosomal recessive immunodeficiency diseases that results from mutation in integrin beta 2 (ITGB2) gene. The aim of this study was to investigate molecular prenatal diagnosis of LAD-1. Four pregnant women with five fetuses (one twin fetus) with clinical and laboratory diagnosis of LAD-1 in their previous children were studied. The chorionic villus sampling (CVS) was obtained when mothers were in 10-12th weeks of gestation. Mutation analysis of ITGB2 gene for affected children revealed 3 misssense mutations (c.382G>A,   a   novel   mutation,   c.2146G>C,   and   c.715G>A)   and   one   splice  site novel mutation (c.1877+2T>C). All parents were heterozygous for these mutations. Consideration of affected gene regions for five CVS samples showed two homozygotes and one heterozygote for mutant allele and two homozygotes for normal allele. Interestingly, one  of  the  twin  fetuses  was  affected  and  another  was  normal.  Briefly, two  cases  of CVS samples were affected and three cases of remained CVS samples were unaffected. This is the first report of prenatal diagnosis of LAD-1 from Iran with two new mutations that can be used for genetic and prenatal diagnosis for all patients suspected to LAD1 and can be helpful to prevent the birth of affected children with LAD-1. This  abstract  was presented  in  the  Second  International  Congress  of  Immunology, Asthma and Allergy, Tehran, Iran 2013

Possible Mechanical and Biological Drivers of Osteoarthritis Following ACL Injury

Anterior cruciate ligament (ACL) rupture has been reported as one of the most prevalent injuries of the knee joint, leading to cartilage degeneration and increased risk of osteoarthritis (OA) development. The present work was aimed at providing a better understanding of some of the potential mechanobiological drivers of OA following trauma, by assessing joint biomechanics (i.e. relative tibiofemoral motions, and ligament and meniscal loading) and boundary lubrication of the ovine stifle joint (i.e. proteoglycan-4 (PRG4) and hyaluronan (HA) composition and lubrication function of ovine synovial fluid) following ACL injury, serially “in vivo”, and their association with gross joint damage. The general working hypothesis was that early (2-4 weeks) lubrication changes after trauma and later mechanical changes (20 weeks) may both contribute to OA development in any individual with an ACL injury. Signs of damage (mild OA) to the cartilage surfaces and menisci of stifle joints in all subjects were observed after ACL injury. Mechanical results demonstrated a significant increase in both medial and lateral meniscal loads 20 weeks following ACL rupture, with interesting inter-subject variability. MCL loads during gait also indicated a general increase; whereas, PCL and LCL loads showed a significant decrease. In terms of biology, the PRG4 and HA composition of ovine synovial fluid was compromised early after injury, but returned to normal state in the long term. Consequently, the cartilage boundary lubricating ability of ovine synovial fluid was also significantly diminished short term post injury, retuning to within normal ranges at 20 weeks. Collectively, these results indicate early changes in joint lubrication and longer term changes in tissue loads after an ACL injury, which, in turn, appear to be associated with some early OA development in the ovine model. This implies that early synovial fluid changes after ACL injury might initiate joint damage; whereas, longer term mechanical changes may amplify that damage toward OA. Further investigation is required to test these speculations, along with the impacts of potential prevention strategies such as enhancement of joint lubrication

The Assessment of Social Support and Self-Care Requisites for Preventing Diabetic Foot Ulcer in Diabetic Foot Patients

Background and Objectives: Diabetic foot as one of the most common complications of diabetes is involved in more than %25 of diabetic patients’ lives, and if not treated properly can lead to amputation up to %20. The lack of self-care is the underlying cause of mortality, morbidity and chronic complications of diabetes. Identification and rectifying of diabetic foot care needs of patients can additionally reduce readmission; also, %85 of diabetic foot problems can be prevented. Materials and Methods: In this descriptive study, 130patients with diabetic foot from Shahid Modarres hospital were selected using census method. Data in forms of demographic questionnaire, self-care requisites assessment tool for preventing diabetic foot ulcer, and Social Support Behavior Scale were completed by patients and then were collected. Data were analyzed by SPSS version 16. Results: In this study, a significant relationship was found between self-care and social support (P<0.05). This means that people with better social support reported better self-care than those with weaker social support. A significant relationship in level of education and monthly income with self-care was seen, as well as in level of education, monthly income and marital status with social support (P<0.001). Conclusions: The results showed that social support can be considered as an effective factor in individual self-care behaviors, and with regard to this factor in educational, treatment and care programs of patients, can improve their self-care, in addition to decreasing economic costs, and improve their qualities of lives as well

Rainfall interception by Quercus castaneifolia, Acer velutium, and Pinus brutia plantations within the growing season in Darabkola Forest of Mazandaran Province

Changes in rainfall interception and consequently in water balance cause essential effects on reforestation by indigenous and exotic tree species in the degraded areas of the Caspian forests. The aim of the present study was to compare the interception of Quercus castaneifolia, Acer velutium, and Pinus brutia plantations during the growing season in Darabkola Forest in eastern part of Mazandaran province in northern Iran. The amount of rainfall (GR) and throughfall (TF) were measured from May to November 2012 by 6 and 20 polyethylene manual gauges with 8 cm diameter each. The rainfall interception was estimated as the difference between TF and GR. During the measurement period 20 rainfall events were recorded. The amount of cumulative GR depth was 346.5 mm. Moreover, the cumulative rainfall interception of Q. castaneifolia, A. velutium, and P. brutia were 86.2 mm, 107.9 mm and 178.3 mm, respectively. The results showed that the rainfall interception was higher during the dry season, from April to September. In addition, significant correlations were observed between rainfall interception and the relative interception for the three plantations (r2 =0.781, 0.716 and 0.618 for Q. castaneifolia, A. velutium and P. brutia, respectively). It is concluded that estimating the amount of rainfall interception is crucial for selecting adapted species for reforestation in the Caspian forests. It is also a prerequisite for calculation of the water balance within reforestations

Copper and selenium levels in women with second-trimester induced abortion in Mazandaran, 2009: A case control study

Abortion is the termination of a pregnancy by the removal or expulsion of a fetus or embryo from the uterus, resulting in or caused by its death. Missed abortion is the most common dangerous condition in pregnancy. An abortion can occur due to maternal complications, chronic disease, endocrine disorders, abortificient drugs, radiation, heavy metals and toxins. The study population consisted of 43 aborted patients and 43 normal pregnant females, referred to Imam Khomeini hospital. 10 mL blood was taken and centrifuged to isolate the patients&rsquo; serum. Then, the samples were analyzed to determine the copper and selenium levels, using atomic absorption spectrometry. All data were statistically analyzed by T-test and Mann-Whitney methods. As a result, we found a significant decrease in serum copper level in cases compared with controls. Also the results showed an insignificant decrease in serum selenium levels in the patients compared to the healthy women. According to the results, deficiency of the essential heavy metals may be a probable reason for missed abortion occurrence. These deficiencies can be related to malnutrition, decreased consumption of essential metals and supplementary compounds in pregnancy, lack of regular laboratory monitoring. Thus, consuming supplements in Iranian pregnant women can be helpful in completing a successful pregnancy