As advancements in total knee arthroplasty progress at an exciting pace, two areas are of special interest, as they directly impact implant design and surgical decision making. Knee
Introduction & aims. Different racial groups show variations in femoral
Introduction and Aims: Currently, multiple femoral component types and sizes exist for primary total hip arthroplasty. However, component sizes for small femoral geometry are generally not available. The purpose of this study is to present the short-term use of a femoral component with sizes that extend into small femoral
Ventral screw osteosynthesis is a common surgical
method for treating fractures of the odontoid peg, but there is still
no consensus about the number and diameter of the screws to be used.
The purpose of this study was to develop a more accurate measurement
technique for the
Data was analysed for both inter-observer and test-retest reliability using the intra-class correlation coefficient and the Bland-Altman method (use of two methods provides a better estimation of accuracy).
Many reports show good results following procedures, such as intervertebral body fusion using cage or total disc replacement, that restore adequate disc height. However, there have been no references regarding the range of normal lumbar disc height in Korean adults which can be used as a standard for the implant size. The purpose of our study is to measure the lumbar disc height on radiographs in normal Korean. 132 subjects (age range 20 to 40 years) who had no previous history of low back pain and no significant finding on physical examination were enrolled. Plain lateral lumbar spine radiograph in supine position were taken. Intervertebral disc heights were measured at anterior, middle and posterior portion of each lumbar disc. The average magnification rate was 115%, and the disc heights were corrected by the magnification rate in each segment. Lumbar disc height showed cranio-caudal pattern in both male and female groups. L4–5 disc heights were highest at anterior, middle and posterior portion in male. L4–5 disc heights were highest at middle and posterior portion in female. L5-S1 disc height was highest at anterior portion in female, but there was no statistically significant difference between L4–5 and L5-S1 disc height at anterior portion. There was no significant difference in disc height between male and female except anterior portion of L1–2 and L2–3 disc. Statistically significant decrease in disc height was not presented in overweight person at all measured site in male and female except posterior portion of L1–2 disc in male. This research is meaningful in that it is an attempt to provide a reference value of lumbar disc height in Korean adults, and the measured values may also be useful in manufacturing Korean modeled artificial lumbar disc prosthesis or surgical instruments for lumbar interbody fusion.
The growing interest in the development of spinal implants has led to an increasing need for biomechanical studies. Porcine spines are commonly used in such studies. Quantitative data of the normal porcine tho-racolumbar spine is lacking, yet these data are crucial to discussion of such studies. In this study we aim to provide such a database to highlight the differences between the porcine and human specimen with a view to help plan future studies contemplating their use. 6 adult (18-24 month old, 60-80 kilograms) male porcine spines were dissected of soft tissue. The lowest thoracic and all the lumbar vertebrae were studied (n=42). 15 anatomical parameters from each vertebra were measured by 2 independent observers using digital calipers (Draper PVC150D, accuracy ± 0.03mm). The mean, SD and SEM were calculated using Micro-soft Excel. Results were compared with available data on human vertebra (Zindrick et al 1987;Panjabi et al 1991,1992; Kumar et al 2000). The inter class correlation coefficient for the observers was 0.997. The intra-observer agreement was statistically robust (0.994). The vertebral body height of the porcine vertebra was larger while both the upper and lower endplate depth and width were smaller than the human specimens. The pedicle width and depth was greater than the human specimen. The spinal canal length and depth of the porcine spine were smaller than humans indicating a narrow spinal canal. The spinous process length showed an increase from T16 to L1. This was in contrast to human spinous process. The results for the measured parameters and their comparison to human specimen will be presented. Results from our study provides a database of anatomical measurements for the porcine vertebrae and highlights the differences with the human specimen. The data would help design future studies contemplating the use of pig spines. Biomechanical studies involving interbody cages, disc replacements and pedicle screw systems should take into account the differences and match implant size accordingly. It also provides valuable information for geometric and Finite Element Modelling of the porcine spine. Further, the results are useful in extrapolation of data from experiments which have used the porcine model.
Assessment of the appropriateness of tendon transfer procedures and the necessity for excising the posterior tibial tendon (PTT) in stage II PTT dysfunction. 12 patients undergoing surgical treatment for unilateral PTT dysfunction underwent magnetic resonance imaging of the tibialis posterior (TP) and flexor digitorum longus (FDL) muscle bellies. All patients had atrophy of the TP muscle compared to the normal leg (mean 10.7%, p = 0.008). In those patients with a complete rupture of PTT there was replacement of the TP muscle by fatty infiltration. Conversely, the FDL muscle showed a compensatory hypertrophy (mean 17.2%, p<
0.002). Treatment of stage II posterior tibial tendon (PTT) dysfunction remains controversial. These findings support the use of FDL as the tendon of choice for augmentation of PTT in stage II disease. This study also demonstrates that in the presence of a complete rupture, excision of the PTT is a reasonable surgical procedure and pure tenodesis will fail because the TP muscle belly undergoes fatty infiltration. In patients with a diseased but intact PTT there was no fatty infiltration and the TP muscle volume was at least 83% of the normal side in all cases. We therefore suggest that in the presence of an intact PTT the TP muscle may provide some useful function if used to augment the FDL transfer when the diseased tendon is excised.
Pre-operative and postoperative radiographs of both hips and pelvis of 160 Malaysian and Australian patients who had undergone Total Hip Replacement (THR) were reviewed. The purpose of the study was to determine morphometric differences in each group that could influence sizing and positioning of cemented total hip implants. In order to measure distances and diameters, we used OSIRIS, a digital radiographic analysis tool provided on the internet by the Department of Medical Imaging, University of Geneva. The known head sizes of the implants were used to calibrate OSIRIS. The patient groups were subdivided into three. We discovered that in general the sizes of the Malaysian population began 1 size below that of the Australian patients. The dimensionally larger 2 groups of the Malaysian patients were similar to the smaller 2 groups of the Australian population leaving a group of small Malaysian femora for whom there were fewer suitable implants We conclude that more work needs to be done to provide suitable implants for South East Asian patients.
Direct measurements were made on 2,166 lumbar vertebrae of 433 adult negro and caucasoid skeletons. On statistical analysis, forty-five vertebrae in twenty-seven skeletons were found to be stenotic, the mid-sagittal diameter being the significantly reduced dimension. Whereas spinal stenosis syndromes are rare in South African negroes, the lumbar canal is marginally narrower in the negro. There is a uniformity of configuration and capacity of the lumbar spinal canal, which transcends race and sex. By a new method of determining the dorsal limit of the lumbar canal on lateral plain radiography, the overall average lower limit of normal of the mid-sagittal diameter is established at 15 millimetres, and of the transverse diameter 20 millimetres. Bony degenerative changes are more likely to cause neurological compression in the nerve root tunnel than in the spinal canal. The role of skeletal narrowing of the spinal canal as an exclusive cause of the spinal stenosis syndrome may have been exaggerated.
While cell morphology has been recognized as a fundamental regulator of cell behavior, few studies have measured the complex cell morphological changes of chondrocytes using quantitative cell
Introduction. Surgeons fixing scaphoid fractures need to be familiar with its morphological variations and their implications on safe screw placement during fixation of these fractures. Literature has limited data in this regard. The purpose of this CT-based study was to investigate scaphoid
Osteoporosis accounts for a leading cause of degenerative skeletal disease in the elderly. Osteoblast dysfunction is a prominent feature of age-induced bone loss. While microRNAs regulate osteogenic cell behavior and bone mineral acquisition, however, their function to osteoblast senescence during age-mediated osteoporosis remains elusive. This study aims to utilize osteoblast-specific microRNA-29a (miR-29a) transgenic mice to characterize its role in bone cell aging and bone mass. Young (3 months old) and aged (9 months old) transgenic mice overexpressing miR-29a (miR-29aTg) driven by osteocalcin promoter and wild-type (WT) mice were bred for study. Bone mineral density, trabecular
Objectives. This study aims to evaluate if micro-CT can work as a method for the 3D assessment and analysis of cancellous bone by comparing micro-CT with undecalcified histological sections in OVX rats. Methods. The mandible and tibia of sham, ovariectomised (OVX) and zoledronate-injected ovariectomised (OVX-ZOL) rats were assessed morphometrically. Specimens were scanned by micro-CT. Undecalcified histological sections were manufactured from the specimen scanned by micro-CT and stained with haematoxylin and eosin. Bivariate linear regressions and one-way analysis of variance were undertaken for statistics using SPSS 16.0.1 software. Results. There were highly significant correlations between undecalcified histological sections and micro-CT for all parameters (bone volume density (BV/TV), bone surface density (BS/BV), trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular separation (Tb.Sp))in the mandible and tibia. Bone histomorphometric parameters analysed by both methods exhibited significant differences among sham, OVX, and OVX-ZOL groups. There were significant correlations between mandible and tibia in BV/TV, BS/BV, and Tb.Sp. Conclusions. Micro-CT is a complementary tool to histological sections in basic research that could improve our understanding of bone histomorphometry. The mandible can be used as an effective site to assess bone
Introduction and Objective. Forced external rotation is hypothesized as the key mechanism of syndesmotic ankle injuries. This complex trauma pattern ruptures the syndesmotic ligaments and induces a three-dimensional deviation from the normal distal tibiofibular joint configuration. However, current diagnostic imaging modalities are impeded by a two-dimensional assessment, without taking into account ligamentous stabilizers. Therefore, our aim is two-fold: (1) to construct an articulated statistical shape model of the normal ankle with inclusion of ligamentous
Chronic glucocorticoid use causes osteogenesis loss, accelerating the progression of osteoporosis. Histone methylation is shown to epigenetically increase repressive transcription, altering lineage programming of mesenchymal stem cells (MSC). This study is undertaken to characterize the action of histone demethylase UTX to osteogenic lineage specification of bone-marrow MSC and bone integrity upon glucocorticoid treatment. Bone-marrow MSC were incubated in osteogenic medium containing supraphysiological dexamethasone. Osteogenic gene expression and mineralized nodule formation were probed using RT-PCR and von Kossa staining. The enrichment of trimethylated lysine 27 at histone 3 (H3K27me3) in Dkk1 promoter was quantified using chromatin immunoprecipitation-PCR. Bone mass and trabecular
Introduction and Objective. In multiple trauma patients, as well as in the healing of isolated fractures (Fx) with heavy bleeding (trauma haemorrhage, TH), complications occur very often. This is particularly evident in elderly patients over 65 years of age. Since these accompanying circumstances strongly influence the clinical course of treatment, the influence of age on bone regeneration after femoral fracture and severe blood loss was investigated in this study. Materials and Methods. 12 young (17–26 weeks) and 12 old (64–72 weeks) male C57BL / 6J mice per group were examined. The fracture group Fx underwent an osteotomy after applying an external fixator. The THFx group also received blood pressure-controlled trauma hemorrhage (35 mmHg for 90 minutes) and reperfusion with Ringer's solution for 30 minutes. The Sham group received only the catheter and one external fixator. μCT scans of the femora were performed in vivo after 2 weeks and ex vivo after 3 weeks. Histological and biomechanical examinations were also carried out. The statistical significance was set at p ≤ 0.05. The non-normally distributed data were analyzed using the Mann-Whitney-U or Kruskal-Wallis test. Results. The histology showed less mineralized bone in the fracture gap in old animals of the Fx (25.41% [1.68%]) and THFx groups (25.50% [4.07%]) compared with the young ones (34.20% [6.36%], p = 0.003; 34.31% [5.12%], p=0.009). Moreover, a severe blood loss lead to more cartilage in both young (6.91% [5.08%]) and old animals (4.17% [1.42%]) compared to animals with only a fracture (2, 45% [1.04%], p=0.004; 2.95% [1.12%], p=0.032). In old animals (11.37 / nm. 2. [17.17 / nm. 2. ]) in contrast the young mice with an isolated fracture (33.6/nm. 2. [8.83/nm. 2. ]) fewer osteoclasts were present (p=0.009). Therefore, the severe blood loss further reduced the number of osteoclasts only in young animals (16.83/nm. 2. [6.07/nm. 2. ]) (p=0.004). In the in vivo μCT, after 2 weeks, a lower volume of bone, cortex and callus was found in old THFx animals (3.14 mm. 3. [0.64 mm. 3. ]); 1.01 mm. 3. [0.04 mm. 3. ]; 2.07 mm. 3. [0.57 mm. 3. ]) compared with the Fx animals (4.29 mm. 3. [0.74 mm. 3. ], p=0.008; 1.18 mm. 3. [0, 25 mm. 3. ], p=0.004; 3.02 mm. 3. [0.77 mm. 3. ], p=0.008) After 3 weeks, the ex vivo μCT scans also showed a reduced callus percentage in old THFx animals (61.18% [13.9 9%]), as well as a low number of trabeculae (1.81 mm. -1. [0.23 mm. -1. ]) compared to animals without blood loss (68.72% [15.71%], p = 0.030; 2.06mm. -1. [0.37mm. -1. ], p=0.041). In the biomechanical test, a reduced elasticity limit of the old THFx mice (7.75 N [3.33 N]) in contrast to the old Fx (10.24 N [3.32 N]) animals was shown (p=0.022). Conclusions. A severe blood loss has a higher negative effect on the healing,
Trochlear dysplasia is a specific morphotype of the knee, characterized by but not limited to a specific anatomy of the trochlea. The notch, posterior femur and tibial plateau also seem to be involved. In our study we conducted a semi-automated landmark-based 3D analysis on the distal femur, tibial plateau and patella. The knee morphology of a study population (n=20), diagnosed with trochlear dysplasia and a history of recurrent patellar dislocation was compared to a gender- and age-matched control group (n=20). The arthro-CT scan-based 3D-models were isotropically scaled and landmark-based reference planes were created for quantification of the