Three-dimensional Reconstruction Software Research Articles

Comparison of tendon–bone healing between autografts and allografts after anterior cruciate ligament reconstruction using magnetic resonance imaging

The purpose of the study is to compare tendon-bone healing between autograft tendons and allograft tendons after anterior cruciate ligament (ACL) reconstruction using 3.0T magnetic resonance imaging. A total of 36 participants (18 with autograft and 18 with allograft reconstruction) underwent MRI scans at least 2years after the ACL reconstruction operation. Oblique axial images were obtained on three-dimensional dual-echo steady-state images and imported into solid modelling software for three-dimensional model reconstruction of the bone tunnel. The graft signal intensity in the tunnel, tendon-bone interface, tunnel morphology, and tunnel area was analysed using the Siemens software packages to determine the tendon-bone healing between the groups. For the tunnel morphology, both groups exhibited bone tunnel enlargement either at the femoral or tibial tunnel aperture. For the tendon-bone interface, one patient in the autograft group and two patients in the allograft group exhibited a significant fibrous scar tissue bands at the tendon-bone interface. The graft signal/noise quotient values of the allograft group were higher than the autograft group. However, there was no significant difference in the tunnel area between the allograft group and the autograft group. Although the autograft tendons exhibited a better remodelling effect than did the allograft tendons in the bone tunnel, there was no significant difference in the tendon-bone healing between the autograft tendons and the allograft tendons postoperatively. These findings indicate that the biomechanical effect of graft motion may play a significant role in the tunnel aperture. III.

Research of Virtual Prototype System on Aiming Device of Setting Screws in Acetabulum Anterior Column

With medical image three-dimensional reconstruction software reconstruct three-dimensional model of the pelvic, Not only the principle of aiming device design is introduced, but also deduces the relationship between the measurements of pre-operative pictures and the angles of drilling ringers of the aiming device, and also compiles applied software for numeration, By the virtual prototype on aiming device of setting screws in acetabulum anterior column, the doctors can simulate the operative environment before operation, The study provides a dependable approach to advance the accuracy rate during operation of acetabulum anterior column setting screws deeply.

Three-dimensional representation software as image enhancement tool in small-bowel capsule endoscopy: A feasibility study

Three-dimensional imaging in capsule endoscopy is not currently feasible due to hardware limitations. However, software algorithms that enable three-dimensional reconstruction in capsule endoscopy are available. Feasibility study. A phantom was designed to test the accuracy of three-dimensional reconstruction. Thereafter, 192 small-bowel capsule endoscopy images (of vascular: 50; inflammatory: 73; protruding structures: 69) were reviewed with the aid of a purpose-built three-dimensional reconstruction software. Seven endoscopists rated visualisation improved or non-improved. Subgroup analyses performed for diagnostic category, diagnosis, image surface morphology and colour and SBCE equipment used (PillCam(®) vs. MiroCam(®)). Overall, phantom experiments showed that the three-dimensional reconstruction software was accurate at 90% of red, 70% of yellow and 45% of white phantom models. Enhanced visualisation for 56% of vascular, 23% of inflammatory and <10% of protruding structures was noted (P=0.007, 0.172 and 0.008, respectively). Furthermore, three-dimensional software application enhanced 53.7% of red, 21.8% of white, 17.3% of red and white, and 9.2% of images of lesions with colour similar to that of the surrounding mucosa, P<0.0001. Application of a three-dimensional reconstruction software in capsule endoscopy leads to image enhancement for a significant proportion of vascular, but less so for inflammatory and protruding lesions. Until optics technology allows hardware-enabled three-dimensional reconstruction, it seems a plausible alternative.

A Morphometric Study of the Semicircular Canals Using Micro‐CT Images in Three‐Dimensional Reconstruction

It is generally accepted that the three semicircular canals are set at right angles to each other and the lateral semicircular canal is smaller than the anterior and posterior semicircular canals. Precise knowledge of the size and spatial relationships of the semicircular canals is vital, and so the 40 petrous parts of the temporal bones were scanned by micro-CT at a slice thickness of 35 µm. The micro-CT images were used in reconstructing three-dimensional models of the bony labyrinth using computer software. Various dimensions of the semicircular canals were measured using the software, and statistical analysis was performed. The anterior semicircular canal was slightly wider than the posterior semicircular canal, and their heights were similar. The radius of curvature of the lateral semicircular canal was 20% smaller than those of the anterior and posterior semicircular canals. The angles between the three canals were not exactly 90 degrees: they were 92.1, 84.4, and 86.2 degrees between the anterior and posterior, anterior and lateral, and posterior and lateral semicircular canals, respectively. We obtained high-resolution images of the semicircular canals using three-dimensional reconstruction software, and these were used to precisely measure the angles between the semicircular canals and the area of the distorted circle formed by each semicircular canal.

Development of an automated nuclear emulsion analyzing system

Abstract This paper describes the development of an automated nuclear emulsion analyzing system, which is constructed of the following three parts, the nuclear emulsion “OPERA film”, the latest automated scanning system “S-UTS” and the three-dimensional track reconstruction software “NETSCAN”. The system is able to operate at a speed of 72 cm 2 /h and overcame the bottleneck of long time-consuming to recognize tracks in the nuclear emulsion by human eyes. The system is essential for the OPERA experiment, muon radiography, gamma-ray telescope and many other fields with nuclear emulsion.

Comparison of Image-Based and Time-of-Flight-Based Technologies for Three-Dimensional Reconstruction of Infrastructure

AbstractAs-built spatial data are useful in many construction-related applications, such as quality control and progress monitoring. These data can be collected using a number of imaging and time-o...

Fluoro-ruby retrograde tracing and three- dimensional visualization of the corticospinal tract in the guinea pig.

Fluoro-ruby was injected into the posterior funiculus of the spinal cord in the cervical (C5–T2) and lumbar (L3-6) segments of adult guinea pigs. The spinal cord was cut into serial frozen sections. The Fluoro-ruby labeling was clearly delineated from the surrounding structure. The labeling traversed the cervical, thoracic and lumbar segments, and was located on the ventral portion of the posterior funiculus on the injected side, proximal to the intermediate zone of the dorsal gray matter. The fluorescence area narrowed rostro-caudally. The spinal cord, spinal cord gray matter and corticospinal tract were reconstructed using 3D-DOCTOR 4.0 software, resulting in a robust three-dimensional profile. Using functionality provided by the reconstruction software, free multi-angle observation and sectioning could be conducted on the spinal cord and corticospinal tract. Our experimental findings indicate that the Fluoro-ruby retrograde fluorescent tracing technique can accurately display the anatomical location of corticospinal tract in the guinea pig and that three-dimensional reconstruction software can be used to provide a three-dimensional image of the corticospinal tract.

The influence of the closing and opening muscle groups of jaw condyle biomechanics after mandible bilateral sagittal split ramus osteotomy

ObjectiveTo investigate the influence of the closing and opening muscle groups of the jaw on mandibular stability after mandibular bilateral sagittal split ramus osteotomy (BSSRO). Materials and methodsTo establish finite element models of four conditions (the normal mandible, preoperative mandibular prognathism, postoperative (BSSRO) mandibular prognathism, and mandibular prognathism following virtual BSSRO), we imported Digital Imaging and Communications in Medicine (DICOM) data into three-dimensional reconstruction software. Finite element analysis software and statistical software were used for analysis of the condylar stress distribution as a function of condylar position during the actions of jaw closing and jaw opening muscle groups. ResultsThe stress distribution of the normal mandibular bilateral condyle was statistically different from the normal mandibular condyle, indicating that bilateral structures are asymmetrical. There was a significant difference in stress distributions with condyle position between healthy control patients and patients prior to mandibular prognathism surgery (P<0.05). There was no significant difference in stress distributions between the normal mandible and the mandible following virtual surgery or real mandibular prognathism surgery. Additionally, there was no significant difference at 6months after mandibular prognathism surgery (P>0.05). ConclusionsBilateral structures of the normal mandible were asymmetrical. After mandibular bilateral sagittal split ramus osteotomy, variation of the force arms of closing and opening muscle groups of the jaw was one of the major factors influencing mandibular stability. Virtual surgery is a promising strategy for preoperative planning to improve surgical success and reduce complications.

Identification of venous variants in the pineal region with three-dimensional preoperative magnetic resonance imaging navigation in patients harbouring tumors in this area: Significance for surgical approach to the lesion

Object The purpose of this study was to identify the anatomy of pineal region venous complex using neuronavigation software when distorted by the presence of a space-occupying lesion and to describe the anatomical relationship between lesion and veins. Moreover we discuss its influence on the choice of the surgical strategy. Methods Of the 33 patients treated at our Institute for pineal region tumors between 2003 and 2008 we used the neuronavigation software to depict the venous system of the pineal region in 14 patients. We focused on depiction of the basal vein of Rosenthal (BV), the internal cerebral vein (ICV) and the vein of Galen: connection patterns between the veins and the type of anatomical distortion caused by the lesion were investigated and classified. Results Using the neuronavigation software for three-dimensional (3D) reconstruction of MRI images the ICV was clearly depicted in all patients on both sides (100%). Last segment of the BV was identified in 25 sides on a total of 28 (89.3%) and absent in 3 of the 28 sides (10.7%). Studying the distortion effect of the tumor on the galenic venous system, three directions of displacement were observed: craniocaudal, anteroposterior and lateral. Seven patients presented a cranial dislocation, 5 patients caudal dislocation and there was no craniocaudal shift in 2 patients. Considering the anteroposterior displacement: 3 subjects showed an anterior shift of the veins, 5 subjects posterior shift and no anterioposterior shift was present in 6 patients. Only 2 of the 14 patients presented lateral displacement of the veins. The principal approaches used in this series were: supracerebellar infratentorial and interhemispheric parieto-occipital. The craniocaudal displacement of the pineal veins seems to be the most important for the choice of the approach. Conclusion The galenic venous system has a central role in the surgery pineal region tumors. Our study demonstrates that the architecture of the pineal veins and their anatomical relationship with the lesion can be depicted with great accuracy by using 3D neuronavigation software in order to facilitate surgical planning and intraoperative orientation.

Tandem-robot Assisted Laparoscopic Radical Prostatectomy to Improve the Neurovascular Bundle Visualization: A Feasibility Study

To examine the feasibility of image-guided navigation using transrectal ultrasound (TRUS) to visualize the neurovascular bundle (NVB) during robot-assisted laparoscopic radical prostatectomy (RALP). The preservation of the NVB during radical prostatectomy improves the postoperative recovery of sexual potency. The accompanying blood vessels in the NVB can serve as a macroscopic landmark to localize the microscopic cavernous nerves in the NVB. A novel, robotic transrectal ultrasound probe manipulator (TRUS Robot) and three-dimensional (3-D) reconstruction software were developed and used concurrently with the daVinci surgical robot (Intuitive Surgical, Inc., Sunnyvale, CA) in a tandem-robot assisted laparoscopic radical prostatectomy (T-RALP). After appropriate approval and informed consent were obtained, 3 subjects underwent T-RALP without associated complications. The TRUS Robot allowed a steady handling and remote manipulation of the TRUS probe during T-RALP. It also tracked the TRUS probe position accurately and allowed 3-D image reconstruction of the prostate and surrounding structures. Image navigation was performed by observing the tips of the daVinci surgical instruments in the live TRUS image. Blood vessels in the NVB were visualized using Doppler ultrasound. Intraoperative 3-D image-guided navigation in T-RALP is feasible. The use of TRUS during radical prostatectomy can potentially improve the visualization and preservation of the NVB. Further studies are needed to assess the clinical benefit of T-RALP.

Application of Mimics and rapid prototyping in atlantoaxial pedicle placement

Objective To develop and validate a novel method of atlantoaxial pedicle screw placement by using three-dimensional reconstruction software Mimics and rapid prototyping. Methods Three-dimensional reconstruction of 20 CT scanned cadaver atlantoaxial specimens was performed by using Mimics and the parameters of the pedicles were measured. Then, physical model of the pedicles was manufactured by using rapid prototyping and the parameters of the cadaver pedicles were measured. The parameters of the atlantoaxial pedicle were directly measured. All the data were analyzed statistically to verify the accuracy of the reconstructed images and physical models. The optimal pedicle channel was found to design individual fixation parameters, based on which fixation of cadaver specimens was performed under direct guidance of physical model. The accuracy of fixation was assessed by CT scanning. Results There was no statistical difference in parameters of the reconstructed images, the physical model and the specimens, which could reflect accurate atlantoaxial anatomy. Postoperative CT scanning showed that the pedicle screws were inserted successfully in 16 sides of four specimens, except for one screw wearing medial bone cortex of the atlas artery. Conclusions Three-dimensional reconstruction of the atlantoaxial specimens by using Mimics and physical models made by rapid prototyping technology facilitate atlantoaxial pedicle screw placement and can enhance the accuracy of screw fixation. Key words: Spinal injuries; Atlantoaxial joint; Fracture fixation,internal; Mimics software

Abdominal aortic aneurysm diameter: A comparison of ultrasound measurements with those from standard and three-dimensional computed tomography reconstruction

Aortic aneurysm size is a critical determinant of the need for intervention, yet the maximal diameter will often vary depending on the modality and method of measurement. We aimed to define the relationship between commonly used computed tomography (CT) measurement techniques and those based on current reporting standards and to compare the values obtained with diameter measured using ultrasound (US). CT scans from patients with US-detected aneurysms were analyzed using three-dimensional reconstruction software. Maximal aortic diameter was recorded in the anteroposterior (CT-AP) plane, along the maximal ellipse (CT-ME), perpendicular to the maximal ellipse (CT-PME), or perpendicular to the centerline of flow (CT-PCLF). Diameter measurements were compared with each other and with maximal AP diameter according to US (US-AP). Analysis was performed according to the principles of Bland and Altman. Results are expressed as mean +/- standard deviation. CT and US scans from 109 patients (92 men, 17 women), with a mean age of 72 +/- 8 years, were included. The mean of each series of readings on CT was significantly larger than the mean US-AP measurement (P < .001), and they also differed significantly from each other (P < .001). The CT-PCLF diameter was larger than CT-AP and CT-PME by mean values of 3.0 +/- 6.6 and 5.9 +/- 6.0 mm, respectively. The CT-ME diameter was larger than CT-PCLF by a mean of 2.4 +/- 5 mm. The US-AP diameter was smaller than CT-AP diameter by 4.2 +/- 4.9 mm, CT-ME by 9.6 +/- 8.0 mm, CT-PME by 1.3 +/- 5 mm, and smaller than CT-PCLF by 7.3 +/- 7.0 mm. Aneurysm size did not significantly affect these differences. Seventy-eight percent of 120 pairs of intraobserver CT measurements and 65% of interobserver CT measurements differed by <2 mm. CT-based measurements of aneurysm size tend to be larger than the US-AP measurement. CT-PCLF diameters are consistently larger than CT-PME as well as CT-AP measurements. These differences should be considered when applying evidence from previous trials to clinical decisions.

Comparison between Three‐Dimensional Angiographic Reconstruction and Intravascular Ultrasound Imaging for the Measurement of Cross‐Sectional Luminal Dimensions in Intermediate Coronary Lesions

Intravascular ultrasound (IVUS) has enabled the measurement of minimal luminal area of coronary stenoses. We evaluated the hypothesis that angiographic three-dimensional reconstruction of luminal dimensions may be able to provide similar measurements to IVUS in intermediate coronary lesions. We retrospectively enrolled patients undergoing invasive coronary angiography and IVUS for the assessment of angiographically intermediate coronary lesions (50-70%) at a high-volume tertiary care hospital between July 1, 2006, and May 20, 2008. IVUS (Boston Scientific, Natick Massachusetts, USA) minimal cross-sectional area (CSA) and minimal luminal diameters (MLD) were compared with the measurements obtained using a sophisticated three-dimensional angiographic reconstruction software (CardiOP-B, Paieon, Inc., Rosh Ha'ayin, Israel), with orthogonal angiographic views used to reconstruct and calculate lesion dimensions. Data were obtained from 34 patients with 35 lesions. The lesions were assessed in the left main (n = 2), left anterior descending artery (n = 15), left circumflex/marginal artery (n = 7), and right coronary artery (n = 11). Using IVUS, the mean minimal CSA was 3.78 +/- 1.60 mm(2), and MLD was 1.88 +/- 0.43 mm. Three-dimensional reconstruction measurements of minimal CSA (3.42 +/- 1.66 mm(2)) highly correlated in a linear fashion with the measurements by IVUS (R = 0.88, P < 0.0001). A three-dimensional angiographic measurement of coronary minimal CSA is highly correlated with the measurements using IVUS. This new software technology may be a promising imaging modality to measure CSAs in coronary lesions.

Thoracic aortic lesions treated with the Zenith TX1 and TX2 thoracic devices: Intermediate- and long-term outcomes

Little data exist to support the durability of thoracic endovascular repair during prolonged periods of follow-up. This study examines the durability and long-term results with the Zenith TX1 and TX2 thoracic devices (Cook Inc, Bloomington, Ind) in high-risk patients. Data were collected prospectively from 2001 to 2007 on high-risk patients who presented with thoracic aneurysms, chronic aortic dissection, or fistulas treated with a Zenith thoracic device. Surgical modifications of proximal or distal landing zones were performed when necessary. Computed tomography follow-up scans were performed before discharge, at 1, 6, and 12 months, and yearly thereafter. Three-dimensional reconstruction software with central line of flow measurements was used to assess aortic morphologic characteristics. Kaplan-Meier analysis was used to assess survival, freedom from reintervention, predictive factors of poor outcome, and morphologic changes, including aneurysm sac behavior. A total of 160 patients (44% women; mean age, 70) were treated for 130 thoracic aneurysms, 25 aortic dissections with aneurysm, 2 fistulas, and 3 symptomatic or aortic ruptures, or both. Mean follow-up was 36 months, and aneurysm size was 67 mm. Seventy-five patients (47%) had undergone prior aortic aneurysm repair. Surgical modifications were required to create adequate landing zones in 33% patients, including 28 elephant trunk/arch reconstruction, 22 carotid-subclavian bypasses, and seven visceral vessel bypasses. Iliac conduits were required in 31 patients. Early mortality (<30 days) occurred in 11 patients (6.9%). Overall mortality at 1 year was 16%. Aneurysm sac increase (>5 mm) requiring intervention was observed only in one patient in the settings of component separation and type III endoleak that was treated; the sac is now stable. Twenty-seven endoleaks were detected in 25 patients: 15 primary endoleaks (9.4%) <30 days and 12 secondary endoleaks (7.5%) >30 days. Secondary interventions were required in 42 patients (26%). Endovascular treatment of thoracic aortic pathologies with the Zenith TX1 and TX2 devices is feasible and durable. The mid- to long-term results are encouraging, with acceptable low reintervention rates and with good survival within high-risk patients.

Efficiently measuring complex sessile epibenthic organisms using a novel photogrammetric technique

This paper describes a stereo photogrammetry method that allows accurate measurements of volume for sessile epibenthic organisms. It represents a novel approach based on multiple views (five stereo image pairs) from a purpose built stereo digital still camera system combined with a three-dimensional reconstruction software program (CAM). The bias, accuracy, precision and efficiency of the method were assessed in the laboratory using models with three levels of morphological complexity (simple, moderate and complex morphologies) and two sizes (large and small). The technique did not show any biases to observer experience, with no significant difference among observers ( p > 0.05). Volume measurements made with CAM were very accurate when compared with the water displacement volume of each model, with an overall mean error of about − 3% (S.E. ± 1%). The CAM volume measurements were more accurate on complex models and moderately complex models than on models with simple morphologies. Also, large models had a higher accuracy than small models. Volume measurements made with CAM were also highly precise with the lowest precision observed being ± 2% of the volume estimate. The time required for a volume estimation using the CAM method was also highly efficient, and the longest time taken for a volume estimation was on average 1 h and 36 min, making it the fastest reported three-dimensional reconstruction method. In field applications, volume estimations of four sponges were all within the observed accuracy, precision and efficiency established during laboratory trials. The accuracy, precision and efficiency demonstrated by the CAM method make this technique highly suitable for routine measurements of the volume of sessile epibenthic organisms.

Age‐dependent and task‐related volume changes in the mushroom bodies of visually guided desert ants, Cataglyphis bicolor

Desert ants of the genus Cataglyphis are skillful long-distance navigators employing a variety of visual navigational tools such as skylight compasses and landmark guidance mechanisms. However, the time during which this navigational toolkit comes into play is extremely short, as the average lifetime of a Cataglyphis forager lasts for only about 6 days. Here we show, by using immunohistochemistry, confocal microscopy, and three-dimensional reconstruction software, that even during this short period of adult life, Cataglyphis exhibits a remarkable increase in the size of its mushroom bodies, especially of the visual input region, the collar, if compared to age-matched dark-reared animals. This task-related increase rides on a much smaller age-dependent increase of the size of the mushroom bodies. Due to the variation in body size exhibited by Cataglyphis workers we use allometric analyses throughout and show that small animals exhibit considerably larger task-related increases in the sizes of their mushroom bodies than larger animals do. It is as if there were an upper limit of mushroom body size required for accomplishing the ant's navigational tasks.

Screening and ultrasound surveillance of large abdominal aortic aneurysms do not improve suitability for endovascular repair

The effect of population screening for abdominal aortic aneurysm (AAA) disease on morbidity and mortality has been comprehensively studied and reported. However, the effect of early AAA detection on suitability for endovascular aneurysm repair (EVAR) remains unknown. Considering the importance of such an effect on future health economics, we sought to assess the possible effect of AAA ultrasound surveillance on suitability for EVAR. This was a prospective cohort study. From January 2002 to August 2003, consecutive AAA patients selected for open elective repair were placed into one of two groups according to mode of presentation. The first group included patients referred from a local well-established AAA ultrasound screening and surveillance program (ultrasound surveillance [AAA-S] group). The second group included patients referred from neighboring unscreened regions with incidentally diagnosed AAA (incidental [AAA-I] group). All patients underwent preoperative computed tomographic angiography. By using three-dimensional reconstruction software, computed tomographic images were assessed by two blinded observers for suitability for EVAR by using the criteria for a modular endovascular device. Of 74 patients included in the study, 41 were in the AAA-S group, and 31 were in the AAA-I group. The median aneurysm diameter was 72.3 mm (range, 50.7-83.7 mm) for AAA-I and 65 mm (range, 50.7-79.2 mm) for AAA-S (P < .47). Suitability for EVAR was 41% in the AAA-S group and 45% in the AAA-I group (P < .47). Early detection and surveillance of AAA does not seem to increase suitability for EVAR. Suitability for EVAR seems to be determined early on in an aneurysm's life. On the basis of current device technology, referral for intervention from an AAA surveillance program may need to be initiated at a size well below 5.5 cm if an increase in EVAR suitability is to be expected.

Late-onset dysphagia lusoria assessed by 3-dimensional computed tomography of an aortic arch abnormality

Symptomatic vascular rings causing late-onset dysphagia (dysphagia lusoria) are quite unusual in adults. We present a 42-year-old woman with a 1-year history of dysphagia from a right-sided aortic arch with an aberrant left subclavian artery and left-sided ligamentum arteriosum. Using a helical CT scan of the chest and a three-dimensional reconstruction software, her anatomic abnormality was completely delineated. Arch aortogram confirmed the anomaly. The patient underwent a left posteriolateral thoracotomy. Intraoperative findings correlated precisely with the preoperative reconstruction data. Division of the ligamentum resulted in a complete decompression of the esophagus and resolution of the patient's symptoms.

Anterior cruciate ligament graft impingement against the posterior cruciate ligament: diagnosis using MRI plus three-dimensional reconstruction software

The purpose of this study was to evaluate anterior cruciate ligament (ACL) impingement against the posterior cruciate ligament (PCL) with the knee in an extended position, which arthroscopy cannot detect. Ten normal knees and 30 ACL-reconstructed knees were assessed using MR imaging. The three-dimensional reconstruction of the ACL, PCL, femur and tibia were carried out using commercially available three-dimensional reconstruction software. Anterior cruciate ligament impingement against the PCL was graded into three categories: Grade 1, some space between the ligaments; Grade 2, no space between the ligaments, and the reconstructed ACL ran straight; and Grade 3, the reconstructed ACL did not run straight. The angle of the reconstructed ACL against the tibial plateau was also measured. All normal knees were classified as Grade 1. The 30 reconstructed knees were classified as follows: Grade 1, 12 cases; Grade 2, 7 cases; and Grade 3, 11 cases. The mean angle of the Grade 3 reconstructed ACL knees was significantly more vertical against the tibia as compared with the Grade 1 knees (P<.05). The postoperative KT-2000 side-to-side difference of the Grade 3 knees (2.8+/-4.5 mm) was larger than that of the Grade 1 knees (0.2+/-1.7 mm) and Grade 2 knees (-0.6+/-2.2 mm), but no statistically significant difference could be detected between the three groups in the postoperative KT-2000 data. This method is useful to evaluate ACL impingement against PCL, which cannot be detected by conventional arthroscopy during the operation. The surgeon should pay careful attention to the coronal angle of the reconstructed ACL.

Anisotropic, Three-Dimensional Deformation of Single Attached Cells Under Compression

Quantifying three-dimensional deformation of cells under mechanical load is relevant when studying cell deformation in relation to cellular functioning. Because most cells are anchorage dependent for normal functioning, it is desired to study cells in their attached configuration. This study reports new three-dimensional morphometric measurements of cell deformation during stepwise compression experiments with a recently developed cell loading device. The device allows global, unconfined compression of individual, attached cells under optimal environmental conditions. Three-dimensional images of fluorescently stained myoblasts were recorded with confocal microscopy and analyzed with image restoration and three-dimensional image reconstruction software to quantify cell deformation. In response to compression, cell width, cross-sectional area, and surface area increased significantly with applied strain, whereas cell volume remained constant. Interestingly, the cell and the nucleus deformed perpendicular to the direction of actin filaments present along the long axis of the cell. This strongly suggests that this anisotropic deformation can be attributed to the preferred orientation of actin filaments. A shape factor was introduced to quantify the global shape of attached cells. The increase of this factor during compression reflected the anisotropic deformation of the cell.