Association of the Posterior Acromion Extension with Glenoid Retroversion: A CT Study in Normal and Osteoarthritic Shoulders

Posterior eccentric glenoid wear is associated with higher complication rates after shoulder arthroplasty. The recently reported association between the acromion shape and glenoid retroversion in both normal and osteoarthritic shoulders remains controversial. The three-dimensional coordinates of the angulus acromialis (AA) and acromioclavicular joint were examined in the scapular coordinate system. Four acromion angles were defined from these two acromion landmarks: the acromion posterior angle (APA), acromion tilt angle (ATA), acromion length angle (ALA), and acromion axial tilt angle (AXA). Shoulder computed tomography scans of 112 normal scapulae and 125 patients with primary glenohumeral osteoarthritis were analyzed with simple and stepwise multiple linear regressions between all morphological acromion parameters and glenoid retroversion. In normal scapulae, the glenoid retroversion angle was most strongly correlated with the posterior extension of the AA (R2 = 0.48, p < 0.0001), which can be conveniently characterized by the APA. Combining the APA with the ALA and ATA helped slightly improve the correlation (R2 = 0.55, p < 0.0001), but adding the AXA did not. In osteoarthritic scapulae, a critical APA > 15 degrees was found to best identify glenoids with a critical retroversion angle > 8 degrees. The APA is more strongly associated with the glenoid retroversion angle in normal than primary osteoarthritic scapulae.

“Validation of Artificial Intelligence Severity Assessment in Metopic Craniosynostosis”

Objective Several severity metrics have been developed for metopic craniosynostosis, including a recent machine learning-derived algorithm. This study assessed the diagnostic concordance between machine learning and previously published severity indices. Design Preoperative computed tomography (CT) scans of patients who underwent surgical correction of metopic craniosynostosis were quantitatively analyzed for severity. Each scan was manually measured to derive manual severity scores and also received a scaled metopic severity score (MSS) assigned by the machine learning algorithm. Regression analysis was used to correlate manually captured measurements to MSS. ROC analysis was performed for each severity metric and were compared to how accurately they distinguished cases of metopic synostosis from controls. Results In total, 194 CT scans were analyzed, 167 with metopic synostosis and 27 controls. The mean scaled MSS for the patients with metopic was 6.18 ± 2.53 compared to 0.60 ± 1.25 for controls. Multivariable regression analyses yielded an R-square of 0.66, with significant manual measurements of endocranial bifrontal angle (EBA) (P = 0.023), posterior angle of the anterior cranial fossa (p < 0.001), temporal depression angle (P = 0.042), age (P < 0.001), biparietal distance (P < 0.001), interdacryon distance (P = 0.033), and orbital width (P < 0.001). ROC analysis demonstrated a high diagnostic value of the MSS (AUC = 0.96, P < 0.001), which was comparable to other validated indices including the adjusted EBA (AUC = 0.98), EBA (AUC = 0.97), and biparietal/bitemporal ratio (AUC = 0.95). Conclusions The machine learning algorithm offers an objective assessment of morphologic severity that provides a reliable composite impression of severity. The generated score is comparable to other severity indices in ability to distinguish cases of metopic synostosis from controls.

Relationship between odontoid fracture angle and cervical sagittal balance

Background: Fractures can occur in various locations within the odontoid process with differing orientations. However, little is known about what factors contribute to the anterior versus posterior angles/orientation of these fractures. Methods: We evaluated 74 patients with odontoid fractures (2013–2018) from a single-institution. Patients’ fracture angles/orientations were measured on computed tomography studies, and were grouped into oblique posterior (OP) or oblique anterior (OA) groups. We also took into account cervical sagittal balance utilizing upright x-rays. Other variables studied included patients’ ages, sagittal balance measurements, and the mechanisms of injury. Results: Fracture angles were significantly steeper in the OP group. OP fractures had larger C2-C7 sagittal vertical axis, occiput-C2 angles, and occiput-C7 angles versus anteriorly oriented fractures. In our linear regression model, advanced age and large occiput-C2 angles were predictive of the odontoid fracture angle. Patients who sustained ground-level falls also had significantly steeper fracture angles versus those involved in motor vehicle accidents. Conclusion: The odontoid tends to fracture at a steep, posterior angle in elderly patients who demonstrate a large positive sagittal balance when the head is extended following a ground-level falls.

STUDY OF GREATER SCIATIC NOTCH FOR DETERMINATION OF SEX OF HIP BONE BY METRIC METHOD

Background: The distinctive morphology of human skeleton and its clear sexual dimorphism make it of interests from anatomical, forensic, obstetrical, radiological and anthropological point of view. The hip bone is considered as an ideal bone for sex determination as it provides the highest accuracy levels. Many workers have studied various metric parameters for sexing of hip bone. Methods: The present study was done with an aim to find out the sex of hip bone using various parameters of greater sciatic notch. For this purpose, 100 dry hip bones were collected from the Department of Anatomy. Seven different parameters of the greater sciatic notch were used for the study: Maximum width, Maximum depth, Posterior segment, Index I, Index II, Total angle and Posterior angle. Results: All the parameters (especially posterior segment, posterior angle and index II) were found to be highly indicative of sex hip bone by t- test (p<0.005) except the depth. Conclusion: By the present study it was concluded that the width and depth of the greater sciatic notch were a less useful criteria for sexing purposes while the posterior angle was found to be the best parameter, which identified 75 % of left and 88 % of right male hip bones and 92 % of left and 100 % of right female bones. Length of the posterior segment and Index II also assigned sex to a high percentage of hip bones, specially to the female ones (95-97 %), these results suggests that the widening of the greater sciatic notch found in females has occurred mainly in its posterior part. Keywords: Hip, Bone, Index

Management of Ala Columella Disproportion in South East Asian Noses

South East Asian noses have a characteristic ala and columella disproportion and mostly manifest as hanging ala. Simultaneous correction during rhinoplasty is recommended to achieve a good aesthetic result. Since hanging ala is a common feature, a classification system is presented as a guide for surgical management. The classification is based on the frontal view showing the alar rim connecting to the columella lobule area simulating the wings of a gull in gentle flight. A mild deformity has the gull's wing in the horizontal direction. A moderate deformity has the gull's wing in a slight inferior direction. A severe hanging deformity has the gull's wing in the inferior direction, ending below the columella lobule area, and this is mostly accompanied by retracted columella. There are various techniques for the surgical correction of hanging ala. The author has made a modification of the internal approach called “sail excision” using the groove within the lateral nasal vestibule as a landmark. The author terms this area as the vestibular groove. Sail excision involves removal of a triangular portion of tissue anterior to this vestibular groove. Another aesthetic deformity noticed in South East Asian noses is that the alar rim base is lower than the columellar base. In correcting hanging ala with involvement of the alar rim base, the sail excision is extended posteriorly following the vestibular groove as its guide to the amount to be excised. To enhance the overall aesthetic outcome, the acute columella labial angle seen in South East Asian noses has to be made fuller through surgery. This is accomplished using septal extension graft for tip projection, with preservation of the posterior angle of the caudal septum. Plumping grafts are used as filler material in the premaxillary area.

Three new species of bristletails of the families Meinertellidae and Machilidae (Archaeognatha) from Ukraine and Southern Russia

Two new species of Machilinus Silvestri, 1905 (M. petrophilus Kaplin, sp. nov., M. obscurus Kaplin, sp. nov.) from Ukraine and one new species of Charimachilis Wygodzinsky, 1939 (C. rostoviensis Kaplin sp. nov.) from Southern Russia are described. The new species of Machilinus belong to the subgenus Machilinus s. str. with 1 + 1 eversible vesicles on urocoxites II–VII, and urostyli with apical spines; to the group “rupestris” with 2nd and 3rd articles of male maxillary palpus without ventral spines (M. obscurus sp. nov.), and with spines on these articles (M. petrophilus sp. nov.). Machilinus petrophilus sp. nov. differs from M. rocai Bach, 1975 in the color and ratio of length to width of compound eyes, the presence of numerous short chaetae on the clypeus, the structure of the lateral apophysis on the 2nd article of the male maxillary palpus, and the number of ventral spines on the legs. Machilinus obscurus sp. nov. differs from the other species of the group “rupestris” in the color of compound eyes, the presence of numerous short chaetae on the male frons and clypeus, and in other features. Charimachilis rostoviensis sp. nov. (Machilidae) most closely resembles C. ukrainensis Stach, 1958. Charimachilis rostoviensis sp. nov. differs from C. ukrainensis in the shape of posterior angle of urosternites, and ratios of lengths of urostyli and urocoxites.

Bilateral acromial stress fractures in a patient with a massive rotator cuff tear

Stress fractures of the acromion and scapular spine are well-known complications following reverse total shoulder arthroplasty. However, these fractures in patients with massive rotator cuff tear or cuff tear arthropathy are extremely rare, and the pathogenesis, clinical features, diagnosis, and treatment of these fractures are poorly understood. We report a case of bilateral stress fracture of the posterior angle of the acromion in a patient with massive rotator cuff tear and discuss the pathogenesis, clinical manifestation, and treatment with a review of the literature.

Role of Plain Radiographs in Assessing Appropriate Placement of Orbital Implants for Repair of Floor Fractures

Intraoperative imaging is becoming increasingly common in repair of facial fractures. Many institutions do not have access to intraoperative advanced 3D imaging but have the capability of obtaining plain radiographs intraoperatively. At institutions where advanced 3D imaging is available, scout radiographs are usually obtained prior to a complete scan. These scout images can provide some information about the placement of radiopaque implants before a complete scan is performed. The aim of this study is to examine the correct anatomic positioning of an orbital floor implant using lateral plain radiographs. Titanium orbital fan implants were molded and secured to orbital floor of 14 adult dry skulls (7 males and 7 females). Lateral radiographs were obtained for both the left and the right orbits individually. The antero-posterior angle of inclination that the implant makes relative to the Frankfort horizontal plane was measured, and results were compared in the male versus female radiographs. The mean angle that the implant made with the Frankfort horizontal plane was 20.1±2.4° in the male orbits (95% CI 18.8-21.5°) and 22.6 ± 2.0° in the female orbits (95% CI, 21.4-23.7°). We found no statistically significant differences between the male and female angles ( P-value 0.62). For the combined specimens (i.e., 28 sides in 14 skulls), the overall mean angle was 21.4 ± 2.5° (95% CI, 20.4-22.3°). Based on these findings, the angle that the implant makes with the Frankfort horizontal plane on lateral cross-table plain radiographs can be used intraoperatively to assist the surgeon in confirming the appropriate placement of the implant.

Physiological Compensation for Advanced Bolus Location at Swallow Onset: A Retrospective Analysis in Healthy Seniors

Purpose Previous work has established that advanced bolus location at swallow onset (BLSO) alone is not correlated with an increased swallowing safety risk in healthy seniors. The primary goal of this retrospective study was to examine whether healthy seniors systematically alter their laryngeal vestibule closure reaction time (LVCrt) to maintain a safe swallow in the context of advanced BLSO. The secondary goal was to determine if longer LVCrt distinguished Penetration–Aspiration Scale (PAS; Rosenbek, Robbins, Roecker, Coyle, & Wood, 1996) scores of 1 versus 2. Method Videofluoroscopy studies from 43 healthy seniors (21 men, 22 women; M age = 76.7 years, SD = 7.2) were analyzed. LVCrt was calculated for 3 × 5 ml and 3 × 20 ml thin liquid barium boluses per participant. PAS and BLSO (Modified Barium Swallow Impairment Profile Component 6) were scored for all swallows. Reliability (intraclass correlation coefficient > .75) was established on all measures. A linear mixed-effects regression was run to examine the effect of PAS and BLSO on LVCrt while controlling for bolus volume and repeated swallow trial. Results There was a main effect of BLSO ( F = 4.6, p = .004) and PAS ( F = 29.3, p < .001) on LVCrt. Post hoc pairwise comparisons revealed that LVCrt was significantly faster in BLSO scores of 3 (pyriforms) compared to scores of both 0 (posterior angle of the ramus) and 1 (valleculae). Significantly prolonged LVCrt was observed in PAS scores of 2 in comparison to 1. No significant main effects of bolus volume or trial, or interactions, were observed. Conclusions Our findings suggest that healthy seniors compensate for advanced BLSO by increasing their LVCrt. Furthermore, faster LVCrt was shown to distinguish PAS scores of 1 versus 2. Additional work should explore the relationship between LVCrt, BLSO, and PAS scores in dysphagic populations, specifically those with known sensory impairments.