-
Frontiers in Veterinary Science 2022Traction was used to diagnose instability of a T5-T6 traumatic luxation that was stabilized with locking plates in the laminae and dorsal pedicles. A two-year-old, 27...
Traction was used to diagnose instability of a T5-T6 traumatic luxation that was stabilized with locking plates in the laminae and dorsal pedicles. A two-year-old, 27 kg, female spayed golden retriever was presented to a veterinary teaching hospital after being referred for possible mandibular and spinal fractures after being hit by a car. The dog presented non-ambulatory paraparetic with intact pain perception. Computed tomographic (CT) imaging showed a fifth and sixth thoracic vertebral fracture/luxation, with and without manual traction. Surgical stabilization of the spine was performed with bilateral dorsally placed locking plates (String-of-Pearls, Orthomed, UK) in the laminae and dorsal aspects of the vertebral pedicles. The dog recovered well, and neurologic status improved significantly overnight and continued to improve up until discharge, which was 6 days postoperatively. Upon recheck exam at 8 weeks postoperatively, the dog appeared neurologically normal with no obvious surgical complications. This case demonstrates that diagnostic traction-the process of pulling, during imaging, on the dog's pelvis while the forelimbs are secured in extension-demonstrated instability of the spine which was not readily apparent on initial CT imaging. Additionally, the dorsal locking plate stabilization is a viable fixation option that provided acceptable stabilization of the mid-thoracic vertebrae.
PubMed: 36619957
DOI: 10.3389/fvets.2022.1011983 -
Acta Radiologica (Stockholm, Sweden :... Sep 2023Wrist pain in the extended or extended weightbearing positions may be incompletely evaluated using standard magnetic resonance imaging (MRI) with standard rigid...
BACKGROUND
Wrist pain in the extended or extended weightbearing positions may be incompletely evaluated using standard magnetic resonance imaging (MRI) with standard rigid clamshell coils in the neutral position.
PURPOSE
To evaluate a flexible 24-channel glove coil and harness when imaging the wrist in neutral, dorsally extended, and weightbearing positions.
MATERIAL AND METHODS
Ten wrists in 10 asymptomatic volunteers (mean age = 29 years) were scanned. Participants underwent 3-T MRI using the harness and flexible glove coil, acquiring sagittal turbo spin echo (TSE) and half-Fourier acquisition single-shot turbo spin echo (HASTE) pulse sequences. Static TSE images were obtained in neutral, extended, and weightbearing positions using proton density parameters and independently evaluated by two radiologists for: dorsal radiocarpal ligament thickness; radiocapitate, radiolunate, and capitatolunate angles; palmar translation of the lunate on the radius; angulation of the extensor tendons; and distance from the distal extensor retinaculum to Lister's tubercle. Cine HASTE images were dynamically acquired between neutral-maximum extension to measure the radiocapitate angle.
RESULTS
Good reader agreement was observed (r > 0.73) for all measurements except palmar translation in the neutral position (r = 0.27). Significant increases in dorsal radiocarpal ligament thickness; radiocapitate, radiolunate and capitolunate angulation; and extensor tendon angulation were observed between the neutral and extended positions ( < 0.001). A further significant increase in these metrics between extended and weightbearing positions was also seen ( < 0.01).
CONCLUSION
Significant increases in dorsal radiocarpal ligament thickness, articular and tendon angulations occur during wrist extension, that further increase with dorsal weightbearing.
Topics: Humans; Adult; Wrist; Pilot Projects; Biomechanical Phenomena; Wrist Joint; Magnetic Resonance Imaging; Volunteers; Ligaments, Articular; Weight-Bearing
PubMed: 37470466
DOI: 10.1177/02841851231188222 -
Cortex; a Journal Devoted To the Study... Jan 2022100 years ago, Liepmann highlighted the role of left ventro-dorsal lesions for impairments in conceptual (rather ventral) and motor (more dorsal) related aspects of...
100 years ago, Liepmann highlighted the role of left ventro-dorsal lesions for impairments in conceptual (rather ventral) and motor (more dorsal) related aspects of apraxia. Many studies thereafter attributed to an extended left fronto-temporo-parietal network. Yet, to date there are only few studies that looked at apraxic performance in the selection and application of familiar versus novel tools. In the current study we applied modern voxel-based lesion-symptom mapping (VLSM) to analyze neural correlates of impaired selection and application of familiar versus novel tools. 58 left (LBD) and 51 right brain damaged (RBD) stroke patients participated in the Novel Tools Test (NTT) and the Familiar Tools Test (FTT) of the Diagnostic Instrument for Limb Apraxia (DILA-S). We further assessed performance in control tasks, namely semantic knowledge (BOSU), visuo-spatial working memory (Corsi Block Tapping) and meaningless imitation of gestures (IML). Impaired tool use was most pronounced after LBD. Our VLSM results in the LBD group suggested that selection- versus application-related aspects of praxis and semantics of familiar versus novel tool use can be behaviorally and neuro-anatomically differentiated. For impairments in familiar tool tasks, the major focus of lesion maps was rather ventral while deficiencies in novel tool tasks went along with rather dorsal lesions. Affected selection processes were linked to rather anterior lesions, while impacted application processes went along with rather posterior lesion maps. In our study, particular tool selection processes were rather specific for familiar versus novel tools. Foci for lesion overlaps of experimental and control tasks were noticed ventrally for semantic knowledge and FTT, in fronto-parietal regions for working memory and NTT, and ventro-dorsally for imitation of meaningless gestures and the application of NTT and FTT. We visualized our current interpretation within a neuroanatomical model for apraxia of tool use.
Topics: Apraxias; Functional Laterality; Gestures; Humans; Imitative Behavior; Magnetic Resonance Imaging; Stroke
PubMed: 34801831
DOI: 10.1016/j.cortex.2021.10.002 -
Journal of Morphology Apr 2016Mouthparts of Leptotrombidium larvae (Acariformes: Trombiculidae), potential vectors of tsutsugamushi disease agents, were studied in detail using light microscopy,...
Mouthparts of Leptotrombidium larvae (Acariformes: Trombiculidae), potential vectors of tsutsugamushi disease agents, were studied in detail using light microscopy, scanning electron microscopy, and transmission electron microscopy. The mouthparts incorporated within the pseudotagma gnathosoma are composed of the infracapitulum ventrally and the chelicerae dorsally. The ventral wall of the infracapitulum is formed by a wide mentum posteriorly and a narrowed malapophysis anteriorly. The malapophysis firmly envelops the distal cheliceral portions by its lateral walls. The lateral lips of the malapophysis are flexible structures hiding the cheliceral blades in inactive condition and turning back forming a type of temporary sucker closely applied to the host skin during feeding. The roof of the infracapitulum is formed by a weakly sclerotized labrum anteriorly and a cervix with the capitular apodemes extending posteriorly. The labral muscles are lacking. The capitular apodemes serve as origin for pharyngeal dilators running to the dorsal wall of the pharynx fused with the bottom of the infracapitulum. The basal cheliceral segments are separated from each other besides the very posterior portions where they are movably joined by the inner walls. The sigmoid pieces serve for insertion of the cheliceral elevators originating at the posterior portions of the basal segments. The movable digits reveal the solid basal sclerite and the cheliceral blade curved upward with a tricuspid cap on its tip. Dendrites of nerve cells run along the digits to their tips. The ganglia are placed within the basal segments just behind the movable digits. The chelicerae also reveal well developed flexible fixed digits overhanging the basal portions of the blades. The gnathosoma possesses several sets of extrinsic muscles originating at the scutum and at the soft cuticle behind it. Laterally, the gnathosoma bears five-segmented palps with a trifurcate palpal claw.
Topics: Animals; Female; Larva; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Mouth; Trombiculidae
PubMed: 26969904
DOI: 10.1002/jmor.20508 -
The Journal of Hand Surgery, European... Dec 2019Dorsal Barton fractures may be better described as variants of dorsal radiocarpal dislocations. We aimed to better characterize these fractures by reviewing 111 patients...
Dorsal Barton fractures may be better described as variants of dorsal radiocarpal dislocations. We aimed to better characterize these fractures by reviewing 111 patients in the ICUC® dataset who had a dorsally displaced, intra-articular distal radius fracture. We identified 13 patients with a dorsal Barton fracture on radiographs (dorsal articular margin fracture with radiocarpal subluxation and intact volar cortex). All patients with a dorsal Barton fracture had radial styloid involvement and volar cortical disruption that was subsequently identified on three-dimensional CT. Based on three-dimensional CT and intra-operative findings, none of the patients had classically described dorsal Barton fractures. All patients were treated using a volar exposure. A volar capsular tear was identified intra-operatively in three patients and the volar capsule repaired. This series supports the contention that dorsal Barton fractures are better characterized and treated as a variation of a dorsal radiocarpal dislocation. IV.
Topics: Adult; Aged; Female; Fracture Dislocation; Fracture Fixation, Internal; Humans; Imaging, Three-Dimensional; Male; Middle Aged; Radius Fractures; Retrospective Studies; Tomography, X-Ray Computed
PubMed: 31488008
DOI: 10.1177/1753193419872639 -
Hand (New York, N.Y.) Dec 2022Distal-ulna stump (DUS) instability often occurs when performing a distal radioulnar joint (DRUJ) arthroplasty. Recent studies suggest that the distal interosseous...
BACKGROUND
Distal-ulna stump (DUS) instability often occurs when performing a distal radioulnar joint (DRUJ) arthroplasty. Recent studies suggest that the distal interosseous membrane (DIOM) reinforces the triangular fibrocartilage complex, providing additional stability to the DRUJ. The aim of this study was to determine whether the DIOM stabilizes the ulnar stump.
METHODS
Twenty fresh-frozen random forearms were dissected. The presence of a distal oblique bundle (DOB) was recorded and measured. The radius was fixed to a vise and the ulna kept free. The DRUJ was fixed with a lag screw. A bone slice was removed by transverse ulna osteotomies 10 and 15 mm proximal to the DRUJ. A 10-N force was applied to the ulna in dorsal and volar directions. Displacements were measured. The DIOM was then transected, and maneuvers and measurements were repeated and compared.
RESULTS
A distinct distal membrane was present in 70% and a cord-like DOB in 30%. The mean length was 29 mm. Its origin was proximal to the sigmoid notch; its insertion was on the distal third of the ulna, at its lateral border. This attachment is comprised between 39 and 48 mm proximal to the ulnocarpal joint. Initial displacements averaged 22 mm dorsally and 13 mm volarly. After DIOM transection, ulnar translocation increased to 31 mm dorsally and 19 mm volarly.
CONCLUSION
In DRUJ arthroplasties, the DIOM does not appear to be a stabilizer of the DUS beneath a useful threshold. Its retaining effect occurs only after an initial 22-mm dorsal displacement, which we consider not clinically admissible. Therefore, in DRUJ arthroplasties, some augmentation might be advisable.
Topics: Humans; Interosseous Membrane; Joint Instability; Biomechanical Phenomena; Cadaver; Ulna
PubMed: 34144664
DOI: 10.1177/1558944721999728 -
Journal of Hand Surgery Global Online Jul 2021Isolated volar metacarpophalangeal dislocations of fingers are extremely rare. There are few cases published in English and French literature. In this article, we aim to...
Isolated volar metacarpophalangeal dislocations of fingers are extremely rare. There are few cases published in English and French literature. In this article, we aim to review the literature and present a case of isolated open volar dislocation of a finger. We treated this dislocation first by a dorsal approach alone and later, after recurrence, using a combined dorsal and volar approach. This report emphasizes the pathology of such injuries, clarifies the mechanisms, and outlines the treatment options of the dislocations. Close reduction can be achieved and maintained if done early. It must be attempted first for all cases. In irreducible or reducible but unstable dislocations, we recommend surgical restoration. During an open reduction, the major torn or avulsed soft tissue joint stabilizers must be repaired. A combined dorsal and volar approach, starting dorsally, is useful.
PubMed: 35415557
DOI: 10.1016/j.jhsg.2021.04.001 -
Veterinary Anaesthesia and Analgesia Jul 2022To compare the cardiopulmonary effects of apneustic anesthesia ventilation (AAV) and conventional mechanical ventilation (CMV) in dorsally recumbent anesthetized horses.
OBJECTIVE
To compare the cardiopulmonary effects of apneustic anesthesia ventilation (AAV) and conventional mechanical ventilation (CMV) in dorsally recumbent anesthetized horses.
STUDY DESIGN
Randomized, crossover design.
ANIMALS
A total of 10 healthy adult horses from a university-owned herd.
METHODS
Following xylazine, midazolam and ketamine administration, horses were orotracheally intubated and positioned in dorsal recumbency. Anesthesia was maintained with isoflurane in oxygen [inspired oxygen fraction (FiO) = 0.3 initially, with subsequent titration to maintain PaO ≥ 85 mmHg (11.3 kPa)]. Horses were instrumented and ventilated with AAV or CMV for 1 hour according to predefined criteria [10 mL kg tidal volume (V), PaCO of 40-45 mmHg (5.3-6.0 kPa) during CMV and <60 mmHg (8.0 kPa) during AAV]. Dobutamine was administered to maintain mean arterial pressure (MAP) >65 mmHg. Cardiopulmonary data were collected at baseline, 30 and 60 minutes. The effects of ventilation mode and time were analyzed using repeated-measures anova with significance defined as p < 0.05.
RESULTS
Data from nine horses were analyzed. A significant effect of mode at one or more time points was found for respiratory rate, arterial and end-tidal CO tensions, arterial pH, mean airway pressure (P), respiratory system dynamic compliance index (CI), venous admixture (Q˙/Q˙), mean pulmonary artery pressure and systemic vascular resistance. No significant differences between modes were found for V, FiO, PaO, arterial hemoglobin saturation, alveolar dead space, heart rate, MAP, cardiac index, stroke volume index, oxygen delivery index, oxygen extraction ratio and dobutamine administration.
CONCLUSIONS AND CLINICAL RELEVANCE
In dorsally recumbent anesthetized horses, both ventilation modes supported adequate oxygenation with minimal supplemental oxygen. Compared with CMV, AAV resulted in higher CI and lower Q˙/Q˙. Despite higher mean P with AAV, the cardiovascular effects of each mode were not different. Further trials of AAV in anesthetized horses are warranted.
Topics: Anesthesia; Animals; Cytomegalovirus Infections; Dobutamine; Horse Diseases; Horses; Humans; Oxygen; Respiration, Artificial
PubMed: 35644741
DOI: 10.1016/j.vaa.2022.04.002 -
Handchirurgie, Mikrochirurgie,... Jun 2023To evaluate and classify carpal alignment in malunited fractures of the distal radius.
PURPOSE
To evaluate and classify carpal alignment in malunited fractures of the distal radius.
MATERIALS AND METHODS
On standardized lateral radiographs of the involved wrist of 72 patients with a symptomatic extra-articular malunion of the distal radius, 43 with a dorsal and 29 with a palmar angulation, radius tilt (RT), radiolunate (RL) and lunocapitate angle were measured. Malposition of the radius was defined as RT plus 11° in dorsal malunion and RT minus 11° in palmar malunion. A palmar tilt of the radius was marked with a minus sign. At the time of corrective osteotomy 9 dorsal malunions underwent for different reasons evaluation of the scapholunate ligament with 4 having a complete scapholunate ligament disruption.
RESULTS
With respect to the RL-angle, carpal malalignment was categorized as follows: type P with a RL-angle less than -12°, type K with a RL-angle between -12 and 10°, type A with a RL-angle more than 10°, but less than the malposition of the radius, type D with a RL-angle greater than the malposition of the radius. All types of carpal malalignment were found in both, dorsally and palmarly tilted malunion. Type A carpal alignment was identified as the leading type in dorsal malunion (25 out of 43 patients), whilst in palmar malunion colinear subluxation of the carpus (type C) was the dominant type (12 out of 29 patients). To return the hand to a neutral position the rotation of the lunate was compensated by a contrarotation of the capitate in the dorsal malunion. In the palmar malunion a dorsal extension of the capitate returned the hand to a neutral position. In 4 of the 5 patients with type D carpal alignment, who had scapholunate ligament evaluation, a complete ligament tear was found.
CONCLUSION
In this study four different types of carpal alignment in malunited extra-articular fractures of the distal radius were identified. Based on this data we suspect that type D carpal alignment in dorsal malunion may be associated with a scapholunate ligament tear. Therefore, we recommend wrist arthroscopy for this group of patients.
Topics: Humans; Radius; Fractures, Malunited; Radius Fractures; Carpal Bones; Wrist Joint; Joint Diseases
PubMed: 37156512
DOI: 10.1055/a-2074-3095 -
PloS One 2017The objective of this study was to assess beak shape variation in domestic turkeys (Meleagris gallopavo) and determine the effects of age, sex, and beak size on beak...
The objective of this study was to assess beak shape variation in domestic turkeys (Meleagris gallopavo) and determine the effects of age, sex, and beak size on beak shape variation using geometric morphometrics. Dorsal and right lateral images were taken of 2442 turkeys at 6 and 18.5 weeks of age. Landmarks were digitized in tpsDig in three analyses of the dorsal upper mandible, lateral upper mandible, and lateral lower mandible shape of each turkey at both ages. The coordinate data were then subjected to a principal components analysis (PCA), multivariate regression, and a canonical variates analysis (CVA) with a Procrustes ANOVA in MorphoJ. For the dorsal images, three principal components (PCs) showed beak shape variation ranged from long, narrow, and pointed to short, wide, and blunt upper mandibles at both ages (6 weeks: 95.36%, 18.5 weeks: 92.21%). Three PCs showed the lateral upper mandible shape variation ranged from long, wide beaks with long, curved beak tips to short, narrow beaks with short, pointed beak tips at both ages (6 weeks: 94.91%, 18.5 weeks: 94.33%). Three PCs also explained 97.80% (6 weeks) and 97.11% (18.5 weeks) of the lateral lower mandible shape variation ranging from wide and round to narrow and thin lower mandibles with superior/inferior beak tip shifts. Beak size accounted for varying proportions of the beak shape variation (0.96-54.76%; P < 0.0001) in the three analyses of each age group. For all the analyses, the CVA showed sexual dimorphism in beak shape (P < 0.0001) with female upper mandibles appearing wider and blunter dorsally with long, curved beak tips laterally. Whereas male turkey upper mandibles had a narrow, pointed dorsal appearance and short, pointed beak tips laterally. Future applications of beak shape variability could have a genetic and welfare value by incorporating beak shape variation to select for specific turkey beak phenotypes as an alternative to beak treatment.
Topics: Animals; Beak; Female; Male; Mandible; Turkeys
PubMed: 28934330
DOI: 10.1371/journal.pone.0185159