Abstract. Objectives.
Background. There is no consensus on which glenoid plane should be used in total shoulder arthroplasty. Nevertheless, anatomical reconstruction of this plane is imperative for the success of a total shoulder arthroplasty. Methods.
Sonographic callus may enable assessment of fracture healing. The aim of this study was to establish a reliable method for
Total temporomandibular joint (TMJ) replacements reduce pain and improve quality of life in patients suffering from end-stage TMJ disorders, such as osteoarthritis and trauma. Jaw kinematics measurements following TMJ arthroplasty provide a basis for evaluating implant performance and jaw function. The aim of this study is to provide the first measurements of
Abstract. OBJECTIVES. An unresolved challenge in osteoarthritis research is characterising the localised intra-tissue mechanical response of articular cartilage. The aim of this study was to explore whether laboratory micro-computed tomography (micro-CT) and digital volume correlation (DVC) permit non-destructive visualisation of
Background. The femoral head center shift on reduction time in total hip arthroplasty (THA) causes alteration of the muscle tension around the hip joint. Many studies about the shift of the femoral head in the cranio-caudal direction or medio-lateral direction on coronal plane have been reported. It has been known widely that the shift on these directions influence tension of the abductor muscle around the hip joint. Nevertheless few studies about the
Objective. In total knee arthroplasty,
We have measured the
We used
Using roentgen stereophotogrammetry we have recorded the
This paper describes how advances in
We report the case of a 12-year-old boy with flexion loss in the left elbow caused by deficient of the concavity corresponding to the coronoid fossa in the distal humerus. The range of motion (ROM) was 15°/100°, and pain was induced by passive terminal flexion. Plain radiographs revealed complete epiphyseal closure, and computed tomography (CT) revealed a flat anterior surface of the distal humerus; the coronoid fossa was absent. Then, the bony morphometric contour was surgically recreated using a navigation system and a
Summary Statement. We used
Purpose: Scoliosis is a
We evaluated the impact of stereo-visualisation of
We have studied the
We created virtual
We investigated the
The
Introduction. Kinematically or anatomically aligned total knee arthroplasty (TKA) has been reported to provide improved clinical outcomes by replicating patient's original joint line [1][2]. It has been known that tibial (joint line) varus varies among patients, and the tibial varus would increase over progression of arthritis and bone remodeling. For those patients with significant deformity, the current tibial varus may significantly differ from its pre-diseased state. In this exploratory study, geometry and alignment of the tibial growth plate were measured with respect to tibial anatomical landmarks in order to better understand modes of tibial deformity and seek possible application in reconstructing pre-diseased joint alignment. Methods. CT scans of sixteen healthy Japanese knees (M6:F10, Age 31.9±13.9 years) were studied.
Glenoid and humeral head bone defects have long been recognized as major determinants in recurrent shoulder instability as well as main predictors of outcomes after surgical stabilization. However, a universally accepted method to quantify them is not available yet. The purpose of the present study is to describe a new CT method to quantify bipolar bone defects volume on a virtually generated 3D model and to evaluate its reproducibility. A cross-sectional observational study has been conducted. Forty CT scans of both shoulders were randomly selected from a series of exams previously acquired on patients affected by anterior shoulder instability. Inclusion criterion was unilateral anterior shoulder instability with at least one episode of dislocation. Exclusion criteria were: bilateral shoulder instability; posterior or multidirectional instability, previous fractures and/or surgery to both shoulders; congenital or acquired inflammatory, neurological, or degenerative diseases. For all patients, CT exams of both shoulders were acquired at the same time following a standardized imaging protocol. The CT data sets were analysed on a standard desktop PC using the software 3D Slicer. Computer-based reconstruction of the Hill-Sachs and glenoid bone defect were performed through Boolean subtraction of the affected side from the contralateral one, resulting in a virtually generated bone fragment accurately fitting the defect. The volume of the bone fragments was then calculated. All measurements were conducted by two fellowship-trained orthopaedic shoulder surgeons. Each measurement was performed twice by one observer to assess intra-observer reliability. Inter and intra-observer reliability were calculated. Intraclass Correlation Coefficients (ICC) were calculated using a two-way random effect model and evaluation of absolute agreement. Confidence intervals (CI) were calculated at 95% confidence level for reliability coefficients. Reliability values range from 0 (no agreement) to 1 (maximum agreement). The study included 34 males and 6 females. Mean age (+ SD) of patients was 36.7 + 10.10 years (range: 25 – 73 years). A bipolar bone defect was observed in all cases. Reliability of humeral head bone fragment measurements showed excellent intra-observer agreement (ICC: 0.92, CI 95%: 0.85 – 0.96) and very good interobserver agreement (ICC: 0.89, CI 95%: 0.80 – 0.94). Similarly, glenoid bone loss measurement resulted in excellent intra-observer reliability (ICC: 0.92, CI 95%: 0.85 – 0.96) and very good inter-observer agreement (ICC: 0.84, CI 95%:0.72 – 0.91). In conclusion, matching affected and intact contralateral humeral head and glenoid by reconstruction on a computer-based virtual model allows identification of bipolar bone defects and enables quantitative determination of bone loss.
The
Introduction:. For 30 years, uncemented anatomic hip stems have been implanted with documented clinical results[1,2]. Their geometry can be linked back to the geometry of the PCA and ABG stems. Modifications to date include stem length, body geometry, material, and reduction in distal geometry. New tools have been developed allowing anatomical measurements and analysis of
Introduction:. The widespread use of TKA promoted studies on kinematics after TKA, particularly of the femorotibial joint. Knee joint kinematics after TKA, including the range of motion (ROM) and the physical performance, are also influenced by the biomechanical properties of the patella. Surgeons sometimes report complications after TKA involvinganterior knee pain, patellofemoral impingement and instability. However, only few studies have focused specially on the patella. Because the patella bone is small and overlapped with the femoral component on scan images. In addition, the patellar component in TKA is made of x-ray–permeable ultra-high molecular weight polyethylene. It is impossible to radiographically determine the external contour of the patellar component precisely. No methods have been established to date to track the dynamic in vivo trajectory of the patella component. In this study, we analyzed the in vivo
The purpose of this study is to investigate the
Purpose. The purpose of this study was to assess the accuracy of
During total knee replacement (TKR), knee surgical navigation systems (KSNS) report in real time relative motion data between the tibia and the femur from the patient under anaesthesia, in order to identify best possible locations for the corresponding prosthesis components. These systems are meant to support the surgeon for achieving the best possible replication of natural knee motion, compatible with the prosthesis design and the joint status, in the hope that this kinematics under passive condition will be then the same during the daily living activities of the patient. Particularly, by means of KSNS, knee kinematics is tracked in the original arthritic joint at the beginning of the operation, intra-operatively after adjustments of bone cuts and trial components implantation, and after final components implantation and cementation. Rarely the extent to which the kinematics in the latter condition is then replicated during activity is analysed. As for the assessment of the active motion performance, the most accurate technique for the in-vivo measurements of replaced joint kinematics is
Introduction and Aims: There is a relationship between the anatomy of the hip joint and the development of arthritis. A common cause of hip pain in the young adult that can lead to arthritis is acetabular dysplasia. More recently, femoroacetabular impingement has been described as another cause of hip pain. The purpose of our study was to evaluate the applicability of pelvic computed tomography (CT) with
Objectives. Whilst gait speed is variable between healthy and injured adults, the extent to which speed alone alters the 3D in vivo knee kinematics has not been fully described. The purpose of this prospective study was to understand better the spatiotemporal and 3D knee kinematic changes induced by slow compared with normal self-selected walking speeds within young healthy adults. Methods. A total of 26 men and 25 women (18 to 35 years old) participated in this study. Participants walked on a treadmill with the KneeKG system at a slow imposed speed (2 km/hr) for three trials, then at a self-selected comfortable walking speed for another three trials. Paired t-tests, Wilcoxon signed-rank tests, Mann-Whitney U tests and Spearman’s rank correlation coefficients were conducted using Stata/IC 14 to compare kinematics of slow versus self-selected walking speed. Results. Both cadence and step length were reduced during slow gait compared with normal gait. Slow walking reduced flexion during standing (10.6° compared with 13.7°; p < 0.0001), and flexion range of movement (ROM) (53.1° compared with 57.3°; p < 0.0001). Slow walking also induced less adduction ROM (8.3° compared with 10.0°; p < 0.0001), rotation ROM (11.4. °. compared with 13.6. °. ; p < 0.0001), and anteroposterior translation ROM (8.5 mm compared with 10.1 mm; p < 0.0001). Conclusion. The reduced spatiotemporal measures, reduced flexion during stance, and knee ROM in all planes induced by slow walking demonstrate a stiff knee gait, similar to that previously demonstrated in osteoarthritis. Further research is required to determine if these characteristics induced in healthy knees by slow walking provide a valid model of osteoarthritic gait. Cite this article: N. Mannering, T. Young, T. Spelman, P. F. Choong.
Introduction: Leg length and offset restoration are known to improve function after total hip arthroplasty, and to minimize the risk of dislocation and limp. Anatomic data of the hip are needed to determine specifications for prosthesis design that restore patient hip anatomy more closely. Furthermore, femoral off-set values calculated on X-Rays may be inaccurate in case of external rotational contracture or high femoral ante-version. The goal of this study was to determine
This randomised study compared outcomes in patients with displaced fractures of the clavicle treated by open reduction and fixation by a reconstruction plate which was placed either superiorly or three-dimensionally. Between 2003 and 2006, 133 consecutive patients with a mean age of 44.2 years (18 to 60) with displaced midshaft fractures of the clavicle were allocated randomly to a
Although it is clear that opening-wedge high
tibial osteotomy (HTO) changes alignment in the coronal plane, which is
its objective, it is not clear how this procedure affects knee kinematics
throughout the range of joint movement and in other planes. Our research question was: how does opening-wedge HTO change
three-dimensional tibiofemoral and patellofemoral kinematics in
loaded flexion in patients with varus deformity?Three-dimensional
kinematics were assessed over 0° to 60° of loaded flexion using
an MRI method before and after opening-wedge HTO in a cohort of
13 men (14 knees). Results obtained from an iterative statistical
model found that at six and 12 months after operation, opening-wedge
HTO caused increased anterior translation of the tibia (mean 2.6
mm, p <
0.001), decreased proximal translation of the patella
(mean –2.2 mm, p <
0.001), decreased patellar spin (mean –1.4°,
p <
0.05), increased patellar tilt (mean 2.2°, p <
0.05) and
changed three other parameters. The mean Western Ontario and McMaster
Universities Arthritis Index improved significantly (p <
0.001)
from 49.6 (standard deviation (. sd. ) 16.4) pre-operatively
to a mean of 28.2 (. sd. 16.6) at six months and a mean of
22.5 (. sd. 14.4) at 12 months. The
Introduction: The purpose of this study was to evaluate the impact of volume rendering 3D computed tomography reconstructions on the inter- and intraobserver reliability of the OTA/AO and Neer classifications in the assessment of proximal humerus fractures. Material and Methods: Four observers with different levels of clinical training classified forty proximal humerus fractures according to the OTA/AO and Neer classifications. Three rounds of evaluation were performed and compared. First, fractures were classified on the basis of plain radiographs alone. Then, four weeks later, the combination of plain radiographs and computed tomography scans with conventional 3D SSD reconstructions was evaluated. Finally, four weeks later, the combination of plain radiographs, computed tomography scans, and 3D volume rendering reconstructions was assessed. These readings were repeated in a newly randomized order after an interval of twelve weeks to evaluate intraobserver reliability. Results: Interobserver reliability for the AO/ASIF classification showed good interobserver reliability with plain radiographs (k=0,65) and two-dimensional CT scans with conventional
Introduction. According to the literature, the gait does not return to normal after THA. However, the
We evaluated the accuracy of a Magnetic Resonance Imaging (MRI)-based method to measure
Patellofemoral Pain Syndrome is characterized by anterior knee pain during activities such as squatting that is thought to be caused by abnormal patellar motion. However, the causative role has yet to be verified since it is difficult to measure the
Unknown femur orientation during X-ray imaging may cause inaccurate radiographic measurements. The aim of this study was to assess the effect of 3D femur orientation during radiographic imaging on the measurement of greater trochanter to femoral head centre (GT-FHC) distance.
A clinical and radiological study was conducted on 97 total hip replacements performed for congenital hip dislocation in 79 patients between 1989 and 1998 using a
Pre-operative computerised
Introduction: The goal of the study was to determine the precision of a
Introduction. Geometric variations of the hip joint can give rise to repeated abnormal contact between the femur and acetabular rim, resulting in cartilage and labrum damage. Population-based geometric parameterisation can facilitate the flexible and automated in silico generation of a range of clinically relevant hip geometries, allowing the position and size of cams to be defined precisely in three dimensions. This is advantageous compared to alpha angles, which are unreliable for stratifying populations by cam type. Alpha angles provide an indication of cam size in a single two-dimensional view, and high alpha angles have been observed in asymptomatic individuals. Parametric geometries can be developed into finite element models to assess the potential effects of morphological variations in bone on soft tissue strains. The aim of this study was to demonstrate the capabilities of our parameterisation research tool by assessing impingement severity resulting from a range of parametrically varied femoral and acetabular geometries. Methods. Custom made MATLAB (MathWorks) and Python codes. [1]. were used to generate bone surfaces, which were developed into finite element models in Abaqus (SIMULIA). Parametric femoral surfaces were defined by a spherical proximal head and ellipse sections through the neck/cam region. This method produced surfaces that were well fitted to bone geometry segmented from CT scans of cam patients and capable of producing trends in results similar to those found using segmented models. A simplified spherical geometry, including the labrum and acetabular cartilage, represented the acetabulum. Femoral parameters were adjusted to define relevant variations in cam size and position. Two radii (small and large cams) and two positions (anterior and superior cams) were defined resulting in four models. Alpha angles of these parametric femurs were measured in an anterior-posterior view and a cross-table lateral view using ImageJ (NIH). A further model was developed using a femur with a medium cam size and position, and the level of acetabular coverage and labrum length were varied. Bones were modelled as rigid bodies and soft tissues were modelled as transversely isotropic linearly elastic materials. With the acetabulum fully constrained in all cases, the femurs were constrained in translation and rotated to simulate flexion followed by internal rotation to cause impingement against the labrum. Results and Discussion. Models generated using the parametric approach showed that potential for tissue damage, indicated through local strain, was not predicted by measured alpha angle, but resulted from cam extent and position as defined by the ellipses. When variations were made to the acetabular rim, an increase in bone coverage had the greatest effect on impingement severity, indicated by strain in the cartilage labral-junction. An increase in labral length increased labral displacement, but had less effect on cartilage-labral strain. Patient specific models currently require full image segmentation, but there is potential to further develop these parametric methods to assess likely impingement severity based on a series of measures of the neck and acetabulum when
Objective. To three-dimensionally reconstruct the proximal femur of DDH (Developmental dysplasia of the hip) and measure the related anatomic parameters, so that we could have a further understanding of the morphological variation of the proximal femur of DDH, which would help in the preoperative planning and prosthesis design specific for DDH. Methods. From Jan.2012 to Dec.2014, 38 patients (47 hips) of DDH were admitted and 30 volunteers (30 hips) were selected as controls. All hips from both groups were examined by CT scan and radiographs. The Crowe classification method was applied. The CT data were imported into Mimics 17.0. The
Minimally invasive (MIS) screw fixation for Hangman's fracture can decrease iatrogenic soft-tissue injury compared with conventional open approach, but increase the risk of instrumentation-related complications due to lack of anatomical landmarks. With the advantages, the intra-operative
The evaluation of knee stability is fundamental for the clinical discrimination between healthy and pathological joints, for the design and evaluation of prostheses and for the definition of articular models. Knee stability can be quantified by measuring the relation between applied single-axis constant loads and corresponding tibio-femoral displacements (i.e., translations and rotations), namely the joint stiffness, at a given flexion angle. No many studies are available in the literature on this topic [1–3]. In particular, the translations/rotations along/about directions different from the loaded one were not deeply investigated. A fresh frozen lower-limb specimen (female, 63 years old, weight 68 Kg, height 158 cm) was considered. The forefoot and all soft tissues outside the knee were removed by a surgeon, keeping the knee joint capsule intact. A stereophotogrammetric system (Vicon Motion Systems Ltd.) was used to measure the femoro-tibial relative motion by two trackers fixed to the bones, thus introducing no soft-tissue artifact. The specimen was then mounted on a test rig capable to exert general loading conditions [4], and constant loads were applied to the tibia: ±100 N in antero-posterior (AP) and medio-lateral (ML) direction; ±10 Nm about abb-adduction (AA) and in-external (IE) rotations. Loads were applied approximately at the mid-point between the lateral and medial epicondyles, and were kept constant while the femur was flexed over a 135° range. Displacements were defined with respect to the joint natural motion (RTNM), also registered with the same rig. The relative motion of the bones was expressed by a standard joint coordinate system [5]. Considerable translations/rotations appeared also on different directions than the loaded one. At 90° of flexion, an anterior load of +100 N produced 5.5 mm of anterior translation, 10.9 mm of medial translation and 12° of external rotation of the tibia (RTNM). When not directly loaded in ML and IE directions, the tibia translated medially and rotated externally, independently from the sign of the applied load: at 90° of flexion, an AA torque of +10 Nm and −10 Nm produced respectively 5 mm and 8.9 mm of medial translation, and 5.5° and 7.5° of external rotation of the tibia (RTNM). The load/displacement relation was highly non linear also for the loading direction. At 90° of flexion, IE torques of +10 Nm and −10 Nm produced respectively 3.6° of internal and 14.2° of external rotation of the tibia (RTNM). The knee joint structures make the relation between applied loads and bone displacements highly non linear. As a result, a load acting on one direction produces a complex
In cases of severe postdysplastic coxarthosis, it seems to be impossible to recognize acetabular geometry and the real femoral position on a plain X-ray because the real diameters and angles can be disfigured when projected. Computed tomography (CT) provides important information to the surgeon about the concavity, shape and stereotomy of the acetabulum. It is quite difficult to correctly evaluate severely changed hips. CT displays more precise acetabular diameters and angles than a plain radiograph. Because of the high density of bony tissue, the CT makes it easy to produce a
The gelatin-based haemostyptic compound Spongostan was tested as a
Objectives. There remains a lack of data on the reliability of methods to
estimate tibial coverage achieved during total knee replacement.
In order to address this gap, the intra- and interobserver reliability
of a
Summary Statement. We successfully delineated the 3D micro morphology of chondrocytes in patella-patellar tendon using IL-XPCT for the first time. Compared with conventional histology, IL-XPCT can not only provide a higher resolution imgaing but also keep the 3D integrity of the specimen. Introduction. The morphology of the bone-tendon junction was complex and quite different from other organs, which result the injured bone-tendon junction repair process too slowly. To study the micro morphology of the bone-tendon junction in 3D may have a great significant value to revealing the repair mechanisms of this pathological process and accelerating injured bone-tendon junction repair. However, it was hindered by the convention methods such as histologic section. In our study, a novel imaging tool, synchrotron radiation based in-line x-ray phase contrast imaging (IL-XPCT) was used to research the 3D micro morphology of the bone-tendon junction. Methods. 1) Sample Preparation: 3 patella-patellar tendons was harvested from the knee joint of New Zealand adult rabbits and was immediately fixed, rinsed in water for 2 hours. Dehydration was done using a series of graded ethanol. The sample was cut out for the CCD pixel resolution in sagittal section. 2) Image Acquisition: The IL-XPCT was performed at the BL13W1 of the Shanghai Synchrotron Radiation Facility (SSRF) in China. The CCD pixel resolution was 0.74 μm. Image Acquisition include three steps, such as the the acquisition of tomo projections, CT slices and and 3D reconstruction of patella-patellar tendon on full scale by using VG Studio Max version 2.1. 3) Histological characterization observation: After scanning, the specimen was cut to histologic sectioning and used for morphology staining by safranin O staining and H&E staining. The histological morphology then compared with the IL-XPCT imaging dateset. Results. (1) The tissue gradations of patella-patellar tendon are clearly detected by IL-XPCT. (2) The 3D reconstruction image of patella-patellar tendon sample were largely match with the histological morphology stained by safranin O and H&E in sagittal view. (3) After the image segmentation, the 3D micro morphology of the bone-tendon junction could be vividly visualised in multi-angles. Through manipulate threshold of the 3D image, we can successfully obtained the 3D morphology of the chondrocyte, and the smallest diameter is approximately 5μm. Discussion & Conclusion. In the present study, we successfully delineated the 3D micro morphological features of chondrocytes in normal patella-patellar tendon using SR-based IL-XPCT for the first time. Compared with conventional histology, IL-XPCT can not only provide a higher resolution ratio without distortion but also keep the
A new method of recording the