Lateral Radiographic Projection Research Articles

APOPHYSEAL AVULSION FRACTURES OF ANTERIOR INFERIOR ILIAC SPINE

We aim to present diagnostic approach and results from surgical treatment in avulsion fractures of the apophysis of Spina Iliaca Anterior Inferior (SIAI).
 Material and methods. During the period 2011 – 2021, seven(7) children with acute traumatic apophysiolysis of SIAI, were operated on, 61 A1.2 fracture by AO/OTA classification. All of the patients are boys with average age 14,1±1,35 years. In all cases the right SIAI is affected and the mechanism of the injury is sports trauma. The diagnostic methods used by us are complete orthopedic clinical examination, AP radiographs of the pelvis and lateral radiographic projections of the hip joint by modified Dunlap technique and also CT scan with 3D reconstruction of the pelvic bones (3cases). In four (4) cases the apophysiolyses are Salter-Harris type I and in three cases – SH type II. The average size of the avulsed bone fragment is 3cm/1cm measured on CT scan and 29,66±3,14 mm on AP radiographic view. Dislocation of the fractured fragment is greater than 1,5cm. In four children the diagnosis from the outpatient care is neglected or primary wrong. This fact procrastinated the treatment for between 15 and 30 days. In the rest of the cases the treatment is prompt in an urgent matter. For all patients open reduction and internal fixation with screw osteosynthesis is performed by using one (4 cases) or two (2 cases) 3,5mm cannulated titanium screws. Consolidation of the fracture and the functional condition by Lower Extremity Functional Scale (LEFS) have been followed.

Cephalometric measurements performed on CBCT and reconstructed lateral cephalograms: a cross-sectional study providing a quantitative approach of differences and bias

BackgroundCephalometric analysis is traditionally performed on skull lateral teleradiographs for orthodontic diagnosis and treatment planning. However, the skull flattened over a 2D film presents projection distortions and superimpositions to various extents depending on landmarks relative position. When a CBCT scan is indicated for mixed reasons, cephalometric assessments can be performed directly on CBCT scans with a distortion free procedure. The aim of the present study is to compare these two methods for orthodontic cephalometry.Methods114 CBCTs were selected, reconstructed lateral cephalometries were obtained by lateral radiographic projection of the entire volume from the right and left sides. 2D and 3D cephalometric tracings were performed. Since paired t-tests between left and right-side measurements found no statistically significant differences, mean values between sides were considered for both 2D and 3D values. The following measurements were evaluated: PNS-A; S-N; N-Me; N-ANS; ANS-Me; Go-Me; Go-S; Go-Co; SNA, SNB, ANB; BaŜN; S-N^PNS-ANS; PNS-ANS^Go-Me; S-N^Go-Me. Intraclass correlation coefficients, paired t-test, correlation coefficient and Bland–Altman analysis were performed to compare these techniques.ResultsThe values of intra- and inter-rater ICC showed excellent repeatability and reliability: the average (± SD) intraobserver ICCs were 0.98 (± 0.01) and 0.97(± 0.01) for CBCT and RLCs, respectively; Inter-rater reliability resulted in an average ICC (± SD) of 0.98 (± 0.01) for CBCT and 0.94 (± 0.03) for RLC. The paired t-tests between CBCT and reconstructed lateral cephalograms revealed that Go-Me, Go-S, PNS-ANS^Go-Me and S-N^Go-Me measurements were statistically different between the two modalities. All the evaluated sets of measurements showed strong positive correlation; the bias and ranges for the 95% Limits of Agreement showed higher levels of agreement between the two modalities for unpaired measurements with respect to bilateral ones.ConclusionThe cephalometric measurements laying on the mid-sagittal plane can be evaluated on CBCT and used for orthodontic diagnosis as they do not show statistically significant differences with those measured on 2D lateral cephalograms. For measurements that are not in the mid-sagittal plane, the future development of specific algorithms for distortion correction could help clinicians deduct all the information needed for orthodontic diagnosis from the CBCT scan.

Foot radiographic angle variation as a function of weightbearing magnitude.

Weightbearing radiographs are widely used to investigate foot disorders. However, it is unclear how imaging during partial weightbearing affects foot alignment measurements. This study aimed to determine a partial weightbearing threshold that yields consistent measurements of various radiographic angles. Eighteen normal fresh-frozen cadaveric foot specimens were dissected and prepared for mechanical testing using a custom-designed, computed tomography-compatible loading frame. Specimens were placed in a neutral ankle position and scanned in five axial loading conditions (0%, 12.5%, 25%, 37.5%, and 50% bodyweight) using weightbearing computed tomography. (Note 50% bodyweight per foot represents full bodyweight in quiet stance.)The lateral first talometatarsal and calcaneal pitch angles were measured on lateral radiographic projections, and the hallux valgus angle and first-second, fourth-fifth, and first-fifth intermetatarsal angles were measured on axial projection images. The lateral first talometatarsal angle decreased significantly with increased bodyweight loading (p < 0.01). Mean significant decreases in the lateral first talometatarsal angle compared to 0% were 6.6° for 12.5%, 7.6° for 25%, 8.8° for 37.5%, and 10.0° for 50% bodyweight loading; 12.5% to 50% was also significant. There was no significant differences between other loading condition pairings or with increased axial load at other angles. The medial longitudinal arch flattened with increasing axial load, resulting in a decreased lateral first talometatarsal angle. However, this radiographic parameter did not change between the 25% and 50% bodyweight conditions, indicating that partial weightbearing imaging (between 12.5% and 25% bodyweight) might be enough to reproduce the sagittal foot alignments observed under full weightbearing conditions in normal feet.

Association of meniscal injury to joint space width on standard tibial plateau leveling osteotomy lateral radiographic projections of the canine stifle.

Up to 70% of dogs with cranial cruciate ligament tears have concurrent meniscal injury, and these injuries can increase the risk of developing osteoarthritis and persistent lameness. Studies assessing joint space width on knee radiographs in people have indicated associations between joint space width and meniscal injuries. The aim of this prospective analytical study was to determine if there was an association between stifle joint space width on three different radiographic projections (the standard tibial plateau leveling osteotomy projections and a standing lateral projection) and meniscal injuries identified at surgery in dogs. There was a significant association between dogs with a meniscal tear and the corresponding joint space width on standard tibial plateau leveling osteotomy lateral radiographic projections (P-value=.0028). Based on receiver operator characteristic curve analysis, joint space widths measuring less than 3.43mm may indicate a meniscal tear, with a corresponding 89.5% specificity and 40.5% sensitivity in dogs weighing 31kg. Joint space narrowing is seen with meniscal tears in dogs, and radiography may be a noninvasive way to identify meniscal tears prior to surgery.

Reliability of the Measurement of Cuboid Height in Midfoot Charcot Neuroarthropathy

Cuboid height is a quantitative radiographic measurement of the relationship of the inferior cuboid to the plantar osseous plane of the lateral column of the foot and might be associated with poor clinical outcomes in patients with midfoot Charcot neuroarthropathy. We evaluated the reliability of the cuboid height measured by a group of foot and ankle surgeons on subjects with midfoot Charcot neuroarthropathy. Ten board-certified foot and ankle surgeons, 10 residents, and 10 medical students measured the cuboid height on 11 lateral weightbearing radiographic projections of subjects with midfoot Charcot neuroarthropathy. Cuboid height measurements were grouped categorically with calculation of an intraclass correlation coefficient (ICC). Ten unique images were used, with 1 repeated image to provide a measure of intrarater agreement. The overall measure of reliability of cuboid height measurement was an ICC of 0.997. Specifically, the ICC was 0.987 for surgeons, 0.992 for residents, and 0.989 for students. Participants were in agreement with the repeated measure in 24 (80.0%) of 30 cases. Specifically, each group (surgeons, residents, and students) were each in agreement for 8 (80.0%) of 10 repeated measurements. In conclusion, these results demonstrate excellent reliability for radiographic measurement of cuboid height on subjects with midfoot Charcot neuroarthropathy. To the best of our knowledge, this is the first investigation to provide a measure of reliability for this radiographic outcome, which is potentially related to clinical outcomes in the evaluation and treatment of this challenging patient cohort.

Can placing lead-rubber inferolateral to the light beam diaphragm limit ionising radiation to multiple radiosensitive organs?

IntroductionThis article investigates a practical method of reducing the impact of scattered radiation during a lateral radiographic projection of the elbow. The light beam diaphragm (LBD) is generally accepted to limit ionising radiation using horizontal and longitudinal lead shutters, yet this article evidences further dose limitation by placing lead-rubber inferolateral to the LBD device. MethodsUsing an anthropomorphic phantom and arm construction scattered radiation was recorded at multiple radiosensitive organs. A 15 cc ionisation chamber (model 10100 AT TRIAD) was placed on each radiosensitive organ (eye, thyroid, breast, testes, spleen and ovaries) measuring exposure rate (μGy/s). Dose readings were recorded before and after the placement of lead-rubber inferolateral to the LBD. A paired two sample t-test was undertaken affirming how likely dose limitation was attributable to chance (p < 0.05). ResultsDescriptive and inferential statistics demonstrate dose reduction to radiosensitive organs (right eye 53%, right breast 53%, left eye 39%, thyroid 13%, left ovary 9%, testes 6%, left breast 3% and spleen 2%) upon placement of the lead-rubber inferolateral to the LBD. The paired two sample t-test demonstrated statistically significant dose limitation (t = 2.04, df = 7, p = 0.04) thus significant for radiographic practice. ConclusionPlacement of lead-rubber inferolateral to the LBD limits dose to multiple radiosensitive organs. Right (53%) and left (39%) eye lens, right breast (53%), thyroid (13%), left ovary (9%), testes (6%), left breast (3%) and spleen (2%) statistically demonstrate dose limiting opportunities to patients.

Radiographic reference limits for cardiac width of budgerigars (Melopsittacus undulatus).

Primary and secondary cardiovascular diseases are not uncommon in birds. Although radiologic standards for heart width have been developed for mammals, they are still not available for many avian species. The purpose of this study was to establish normal reference values for cardiac size in budgerigar (Melopsittacus undulatus), one of the most popular pet bird species all over the world. After clinical and radiographic (lateral and ventrodorsal views) evaluations, 27 adult, clinically healthy budgerigars (10 females and 17 males) were included in this study. High-quality ventrodorsal and lateral radiographic projections were obtained. The cardiac and thoracic width, distance between third and fourth ribs, synsacrum width, coracoid width, and the distance between clavicle bones were measured on ventrodorsal radiographs. The ratio between cardiac width and other mentioned indices was calculated. Correlation of each anatomical index with the cardiac width was evaluated by linear regression model. Sex and weight were included in all models. Mean + SD of cardiac width was 10.8 +/- 0.6 mm, with lower and upper limits of 9.5 and 12.0 mm. The results showed a significant correlation between the cardiac width and the thoracic width (R2 = 0.28; P = 0.005). There were no significant associations between weight, sex, and the heart width. The values and ratios obtained in this study can be used as a reference of normal cardiac size of budgerigar in radiology for detection of cardiomegaly in this bird.

Variability associated with assessing changes in position of a canine uncemented femoral stem prosthesis.

Evaluate variability associated with assessing changes in the position of uncemented femoral stems. Stem level, canal fill, stem angle, and version angle were measured on craniocaudal horizontal beam (CCHB) and open leg lateral (OLL) radiographic projections of the femur of 20 dogs that had uncemented total hip replacement. Intraobserver and interobserver repeatability were determined on immediate postoperative (PO) images. Differences in position were calculated between the first (3 months - R1) and second (6 months - R2) re-evaluation (R1-R2) time points, and between PO and R1. The measurement process was very repeatable. For R1-R2, the stem appeared to subside 0.8 ± 1.4 mm for measurements based on the greater trochanter on the CCHB images, but there was a wide range (-3.9 to 2 mm; positive values indicate proximad movement). Measurements based on the intertrochanteric crest on the OLL images had the same mean, and also a wide range (-4.4 to 2.1 mm; negative values indicate proximad movement). For PO-R1, the stem appeared to subside 1.8 ± 2.0 mm (CCHB, based on the greater trochanter, range -7.7 to 2.2 mm), 1.6 ± 1.5 mm (CCHB, based on the intertrochanteric crest, range -0.7 to 4.3 mm); and 2.1 ± 2.1 mm (OLL, based on the intertrochanteric crest, range -1.6 to 6.8 mm). The position of a stable stem can appear different on subsequent re-evaluations, but this may be due to variability associated with inconsistency of positioning of the patient and limb. Documenting subsidence in individual patients should not rely on calculations based on a single measurement.

Radiographic Assessment of Posterior Malleolar Ankle Fractures

The anatomy of the posterior tibial malleolus plays an important role in the structure and function of the ankle mortise. With specific respect to ankle fractures, the presence, size, and displacement of posterior malleolar fractures (Volkmann's fracture) helps determine which will be amendable to operative fixation. The objective of the present study was to increase the body of knowledge with respect to the ability of foot and ankle reconstructive surgeons to assess posterior malleolar ankle fractures using plain film radiography. Three different variables were investigated on Sawbones® models: (1) differing size of posterior malleolar fractures (10%, 25%, and 50% of the tibial plafond), (2) differing displacement of posterior malleolar fractures (0 and 5 mm of proximal displacement), and (3) 2 different radiographic projections (standard lateral and externally rotated lateral projections). Accurate identification of the posterior malleolar fracture occurred on 86.67% (26 of 30) of standard lateral radiographs and 100% (30 of 30) of externally rotated lateral radiographs. Furthermore, the surgeons described the fracture with greater precision and had greater interclass correlation coefficient values with respect to measurement of sagittal plane displacement (0.977 versus 0.939) and percentage of involvement of the tibial plafond (0.972 versus 0.775) with an externally rotated lateral projection compared with a standard lateral projection. Our results provide evidence that an externally rotated lateral radiographic projection can provide surgeons with some additional information with respect to the presence, size, and displacement of posterior malleolar ankle fractures.

Primary cranial mediastinal hemangiosarcoma in a young dog.

Primary cranial mediastinal hemangiosarcomas are uncommon tumors. A 30-kg, 2-year-old, intact female German shepherd was presented for evaluation of cachexia and respiratory distress of a few days’ duration. Lateral radiographic projection of the thorax revealed significant pleural effusion. Computed tomography revealed a cranial mediastinal mass effect adjacent to the heart. On surgical exploration, a pedunculated mass attached to the esophagus, trachea, brachiocephalic trunk, left subclavian artery and cranial vena cava without attachment to the right atrium and auricular appendage was removed and debrided by use of blunt dissection and dry gauzes, respectively. Histopathology results described the cranial mediastinal mass as hemangiosarcoma. At 8 months and 5 days post-operatively, the patient died. Primary cranial mediastinal hemangiosarcomas, although a seemingly rare cause of thoracic pathology in young dogs, should be considered in the differential diagnosis for pleural effusion and soft tissue mass effect in the cranial mediastinum. This is the first case report in a dog to describe primary cranial mediastinal hemangiosarcoma.

Use of electrical nerve stimulation to monitor lumbosacral epidural needle placement in cats

ObjectiveTo determine the minimal electrical threshold (MET) necessary to elicit muscle contraction of the pelvic limb or tail when an insulated needle is positioned outside (METout) and inside (METin) the lumbosacral epidural space in cats. Study designProspective, blinded study. AnimalsTwelve mixed-breed healthy adult cats, scheduled for a therapeutic procedure where lumbosacral epidural administration was indicated. MethodsUnder general anesthesia, an insulated needle was advanced through tissues of the lumbosacral interspace until its tip was thought to be just dorsal to the interarcuate ligament. An increasing electrical current (0.1 ms, 2 Hz) was applied through the stimulating needle in order to determine the MET necessary to obtain a muscle contraction of the pelvic limb or tail (METout), and then 0.05 mL kg−1 of iohexol was injected. The needle was further advanced until its tip was thought to be in the epidural space. The MET was determined again (METin) and 0.2 mL kg−1 of iohexol was injected. The cats were maintained in sternal position. Contrast medium spread was determined through lateral radiographic projections. ResultsThe radiographic study confirmed the correct needle placement dorsal to the interarcuate ligament in all cats. When the needle was placed ventrally to the interarcuate ligament, iohexol was injected epidurally in ten and intrathecally in two cats. The METout and METin was 1.76 ± 0.34 mA and 0.34 ± 0.07 mA, respectively (p < 0.0001). Conclusion and clinical relevanceNerve stimulation can be employed as a tool to determine penetration of the interarcuate ligament but not the piercing of the dura mater at the lumbosacral space in cats.

Defining the Lateral and Accessory Views of the Patella

The majority of orthopaedic surgeons rely on a lateral fluoroscopic image to assess reduction during patella fracture osteosynthesis. However, a comprehensive radiographic description of the lateral view of the patella has not been performed previously, and no accessory views to better visualize specific anatomic features have been developed. The purpose of this study was to provide a detailed anatomic description of all radiographic features of the true lateral of the patella, describe reproducible accessory views for assessing specific features of the patella, and demonstrate their utility in a fracture model. Twelve cadaver knee specimens free of patellofemoral pathology were used, and imaging was performed using standard C-arm fluoroscopy. For each specimen, a true lateral radiographic projection of the patella was obtained and distinct features were noted. Next, an arthrotomy was made and steel wire was contoured and fixed to various anatomic regions of the patella so as to obliterate the radiographic densities on the true lateral projection, thus confirming their anatomic correlation. Ideal views of the lateral and medial facets themselves were determined using radiographic markers and varying amounts of internal or external rotation of the specimen. Last, a transverse osteotomy was created in each patella and the ability of the true lateral and accessory views to detect malreduction was assessed. The true lateral projection of the patella was obtained with the limb in neutral alignment. Constant radiographic features of the lateral view of the patella include the articular tangent, a secondary articular density of variable length, and a dorsal cortical density. The articular tangent was produced by the central ridge between the medial and lateral facets in all specimens. The secondary articular density was created by a confluence of the edge of the lateral and edge of the medial facets in 5 patellas, a confluence of the edge of the lateral facet and the intersection of the odd and medial facets in 6 patellas, and the edge of the lateral facet alone in 1 patella. The edge of the lateral facet gave a constant contribution to the appearance of the secondary articular density in all cases. A distinct accessory view of the tangent of the lateral facet could be seen with an average of 17 degrees of patella external rotation (range, 12-35 degrees), and the tangent of the medial facet with an average of 26.5 degrees of internal rotation (range, 15-45 degrees). These accessory views were better able to visualize malreduction than the single lateral projection in a fracture model in all specimens. Described here is a comprehensive description of the true lateral radiographic view of the patella and accessory views. These views can be used in the evaluation of minimally displaced patella fractures if a computerized tomography is not desired to better assess the true amount of displacement and when assessing intraoperative reduction during patella fracture osteosynthesis.

Radiographic localization and isometry of the origin and insertion of the canine cranial cruciate ligament

To radiographically define the anatomic origin and insertion of the cranial cruciate ligament translated to the lateral radiographic projection of the stifle (CrCL-Lo and CrCL-Li, respectively), to correlate these landmarks for identification of the CrCL-Lo intraoperatively, and to compare the isometry of the CrCL-Lo to the lateral fabella. Experimental study. Pelvic limbs (n = 12) from dogs weighing 13-26 kg. A radiographic quadrant method was used to localize the CrCL-Lo. Mediolateral radiographic projections of each stifle were taken through a range of motion. Maximum percent change in length between each tibial marker and femoral marker during range of motion determined isometry. The CrCL-Lo is located at the caudal 33% and distal 50% of the lateral femoral condyle using Blumensaat's line or a line from the origin of the long digital extensor (LDE) to the lateral fabella, with no significant difference (P = .766) between the 2 reference lines. The CrCL-Li is located at the proximal 20% of the tibial plateau. No significant difference (P < .05) in isometry was found between the CrCL-Lo and lateral fabella. The CrCL-Lo is located at the caudal 1/3 and distal ½ of the lateral femoral condyle. The CrCL-Lo and lateral fabella are not significantly different in isometry when used as a proximal anchor point in extracapsular stifle stabilization.

Assessment of Acetabular Cup Positioning from a Lateral Radiographic Projection after Total Hip Replacement

To demonstrate first that a ventrodorsal radiographic (VDR) projection is inadequate for obtaining accurate acetabular cup position (ACP) measurements after total hip replacement (THR), and second to validate use of the lateral radiographic (LR) projection to measure ACP. In vitro study. Eleven VDRs were obtained after insertion of a cup into the acetabulum of a Sawbones pelvis fixed at an approximated angle. For each VDR, the pelvis was placed in varying degrees of craniocaudal pelvic tilt (CCPT). Fifteen LRs were obtained of a Sawbones pelvis with varying ACPs. Five blinded observers made previously described measurements of ACP on each VDR and angle of lateral opening (ALO) and coronal retroversion (CR) on each LR. An almost perfect level of agreement was observed between 5 observers for the repeatability of both VDR and LR measurements. When varying degrees of CCPT were introduced, there was no agreement in the measurements of ACP from VDRs. In all cases, and at all ACPs, measurements taken from LRs were in agreement. Undetectable CCPT causes significant variability in ACP measurements on VDRs predisposing postoperative radiographic measurements to inaccuracy. Measurements obtained from an LR of CR and ALO are accurate and consistent between observers and it should be used to measure ACP. The VDR should be performed to assess bone and implant integrity but not to obtain measurements of ACP because of CCPT causing measurements to be unreliable. Measurements of ACP obtained from an LR in conjunction with femoral anteversion may allow for investigation of the influence of ACP on coxofemoral joint luxation after THR.

Incidence of Transcortical Tibial Fractures with Self‐Tapping and Non‐Self‐Tapping Screws in a Canine TPLO Model

To compare the incidence of radiographically apparent transcortical diaphyseal tibial fractures between self-tapping screws (STS) and non-self-tapping screws (NSTS) in a canine tibial plateau leveling osteotomy (TPLO) model. Case series. Dogs (n = 106) that had TPLO. NSTS (n = 107), STS titanium (n = 104), or STS stainless steel (n = 105) screws were used for TPLO. Effect of STS and NSTS were compared by reviewing postoperative craniocaudal and lateral radiographic projections taken immediately after TPLO. Three screws distal to the tibial osteotomy served as the in vivo model for canine cortical bone. A transcortical fracture was defined as the presence of a saucer-shaped radiolucent defect on the periosteal surface of the trans-cortex surrounding the screw and the presence of radiopaque material (bone) separate from the transcortical periosteal surface. The effect of screw type and STS material (stainless steel or titanium) on the incidence of transcortical fractures was evaluated. STS had a significantly higher (P = .006) incidence of transcortical fractures (18.0%) compared with NSTS (0.8%). The effect of STS material on the incidence of transcortical fractures was not significant (P = .485). No cis-cortical factures were identified. We suspect the increased incidence of transcortical fractures with STS is because of the shorter cutting flutes as compared with those of a tap used with a NSTS.

The Effect of Shock Wave Therapy on Patellar Ligament Desmitis after Tibial Plateau Leveling Osteotomy

To determine if shock wave therapy (SWT) after tibial plateau leveling osteotomy (TPLO) has a beneficial effect on patellar ligament inflammation assessed by thickening of the ligament and ligament fiber disruption. Prospective, randomized, controlled clinical trial. Dogs (n = 30). Dogs that had TPLO (July 1, 2009 to June 1, 2010) were enrolled. The affected stifle was examined by radiographs and ultrasonography preoperatively and 4, 6, and 8 weeks after TPLO. At 4 and 6 weeks, dogs in the treatment group were briefly anesthetized and treated with SWT. Patellar ligament thickness on a lateral radiographic projection was measured at 1/4, 1/2, 3/4 of the distance from origin to insertion. Ultrasound images were evaluated for patellar ligament disruption and periligament edema. There was significant difference in thickness (P = .0264) only at the distal point; therefore, only this point was used to measure difference between the control and treatment groups. A significant difference between groups was reached at 6 and 8 weeks (P = .0059 and P = .0095, respectively) postoperatively. No significant ultrasonographic differences were found. Based on these results, SWT decreases the radiographic signs of patellar ligament desmitis.

Feasibility of a novel material for the reconstruction of skull base in a canine

To explore the therapeutic efficacy of a novel complex material of shape-memory alloy brace and artificial dura (nitinol brace and NormalGEN) for the reconstruction of skull base in a canine model with lateral media skull base defect. The complex of nitinol brace and NormalGEN was developed with corresponding apparatus. A common adult dog model with lateral media skull base defect was established and then reconstructed with the complex. At Month 3 post-operation, cranial lateral radiographic projection, three-dimensional reconstruction of computer tomography, 1.5T magnetic resonance imaging and histopathological examination were detected. Five animal models and cranial reconstructions were made. All survived without any complication, such as leakage of cerebrospinal fluid, local tissue eminence and neurological function defect. The imaging detection showed that nitinol brace was distinct and satisfactorily positioned without shift and artifact. And histopathological examination showed that granulation tissue substituted NormalGEN and grew around the brace with numerous fibroblasts. The complex of shape-memory alloy brace and artificial is suitable for the reconstruction of skull base on dog model with lateral media skull base defect.

Manual and Computerized Measurement of Sagittal Vertebral Inclination in Computed Tomography Images

Sagittal vertebral inclination (SVI) was systematically evaluated in computed tomography (CT) images by three observers using six manuals and two computerized measurements. To analyze and compare manual and computerized measurements of SVI in CT images. A number of methods were proposed to measure SVI in lateral radiographic projections in the form of spinal curvature or segmental angulation. A systematic analysis of the manual and computerized measurements in sagittal CT cross-sections has not been performed yet. SVI was measured in CT images for 28 vertebrae independently by three observers. Manual measurements were obtained in sagittal cross-sections by manually identifying the vertebral body corners, which defined the lines of SVI (superior and inferior tangents, anterior and posterior tangents, mid-endplate and mid-wall lines) against reference horizontal or vertical lines. Computerized measurements were obtained by manually identifying the vertebral centroids, which initialized the automated method that evaluated SVI by searching for the planes of maximal symmetry of vertebral bodies in two dimensions and in three dimensions. The midwall lines proved to be the most reproducible and reliable manual measurements (1.0° and 1.4° standard deviations [SD]). The computerized measurements in three dimensions were more reproducible and reliable (0.9° and 1.3° SD) and also most consistent with the midwall lines (2.1° SD and 1.7° mean absolute difference). The manual measurements based on mid-wall lines and the computerized measurements in three dimensions yielded the lowest intraobserver and interobserver variability of SVI. However, in terms of speed and operator friendliness, the computerized measurements may represent an adequate alternative to manual measurements.

Growth Dynamics of the Canine Proximal Tibial Physis

To determine growth of the proximal tibial physis in the Labrador Retriever, a breed of dog at risk for rupture of the cranial cruciate ligament (CCL). Male Labrador Retriever dogs (n=6). Tantalum markers (0.5 mm diameter) were implanted in the right proximal tibial epiphysis and metaphysis of each dog at 16 weeks of age. Lateral and craniocaudal radiographic projections of the tibia were made monthly and longitudinal growth was assessed from radiographs; a growth curve was generated from the data. Data from dogs that had undergone proximal tibial epiphysiodesis (PTE) was compared with the growth curve to demonstrate if the growth curve accurately predicted changes in the growth associated with this procedure. Growth rate of individual dogs decreased slowly and non-linearly over the 1st year of age. Growth from the proximal tibial physis is described. Growth of individual dogs described here follows the model of saltation and stasis. The growth curve generated predicted the change in tibial plateau angle (TPA) for two Labrador Retrievers that had PTE (± 1°).

Ex Vivo Biomechanical Evaluation of the Canine Cranial Cruciate Ligament‐Deficient Stifle with Varying Angles of Stifle Joint Flexion and Axial loads after Tibial Tuberosity Advancement

To evaluate the effect of tibial tuberosity advancement (TTA) on cranial tibial thrust (CrTT), retropatellar force (RPF), patellar tendon load (PTL), and patellar tendon angle determined by the tibial plateau angle (PTA(TPA) ) method or common tangent (PTA(CT) ) method in the canine cranial cruciate ligament (CrCL)-deficient stifle joint. Ex vivo cadaver study. Cadaveric canine hind limbs (n=30). Stifle joints were subjected to 3 differing loading conditions using a constrained limb press model (Group 1: 30% body weight axial load at stifle and talocrural joint angles of 135 ± 5° and 145 ± 5°, respectively; Group 2: 30% body weight axial load at stifle and talocrural angles of 145 ± 5° and 135 ± 5°, respectively; and Group 3: 50% body weight axial load at stifle and talocrural joint angles of 135 ± 5° and 145 ± 5°, respectively). The CrCL was transected in situ under load; sensors allowed direct measurement of CrTT, RPF, and PTL. Lateral radiographic projections were used to assess PTA(TPA) and PTA(CT) . Descriptive statistics were used to report CrTT (by design this force returned to 0-point values, defined as the neutral point of advancement [NPA]). At the NPA, RPF was compared with baseline using a 2-tailed sign test. PTL within groups were compared using a paired t-test; pair-wise comparisons of PTA(TPA) and PTA(CT) were performed using a paired t-test. Comparisons between loading conditions were made with a 1-way ANOVA and Tukey's post hoc test. Equivalence tests were used to test mean PTA(TPA) and PTA(CT) for equivalence to 90°. Significance was set at a P-value of .05. CrTT returned to baseline values, and RPF and PTL at NPA were reduced below baseline values in all specimens in a near linear fashion with TTA. At the NPA, PTA(TPA) >PTA(CT) in 2 of the 3 loading conditions, but insufficient evidence to suggest they differed in the third. Mean PTA(TPA) and PTA(CT) varied between loading conditions. The threshold for each of the groups evaluated, at which the PTA could be significantly different from 90°, was larger for PTA(TPA) than PTA(CT) in all groups, as greater variation was observed with PTA(TPA) versus PTA(CT) . This study further supports the claim that reduction of CrTT occurs after TTA in the CrCL-deficient stifle joint through an alteration of PTA. Additionally, RPF and PTL also decrease after TTA. The PTA(CT) may be a more precise method of determining PTA.