Posterior Extension Research Articles

Influence of extending expansive open-door laminoplasty to C1 and C2 on cervical sagittal parameters

BackgroundFor patients with spinal canal stenosis in the upper cervical spine who undergo C3–7 laminoplasty alone, it remains impossible to achieve full decompression due to its limited range. This study explores the extension of expansive open-door laminoplasty (EODL) to C1 and C2 for the treatment of cervical spinal stenosis of the upper cervical spine and its effects on cervical sagittal parameters.MethodsA retrospective analysis of 33 patients presenting with symptoms of cervical spondylosis myelopathy (CSM) and ossification in the posterior longitudinal ligament (OPLL) of the upper cervical spine from February 2013 to December 2015 was performed. Furthermore, the changes in the C0–2 Cobb angle, C1–2 Cobb angle, C2–7 Cobb angle, C2–7 SVA, and T1-Slope in lateral X-rays of the cervical spine were measured before, immediately after, and 1 year after the operation. JOA and NDI scores were used to evaluate spinal cord function.ResultsThe C0–2 and C1–2 Cobb angles did not significantly increase (P = 0.190 and P = 0.081), but the C2–7 Cobb angle (P = 0.001), C2–7 SVA (P < 0.001), and T1-Slope (P < 0.001) significantly increased from preoperative to 1 year postoperative. In addition, C2–7 SVA was significantly correlated with the T1-Slope (Pearson = 0.376, P < 0.001) and C0–2 Cobb angle (Pearson = 0.287, P = 0.004), and the C2–7 SVA was negatively correlated with the C2–7 Cobb angle (Pearson = − 0.295, P < 0.001). The average preoperative and postoperative JOA scores were 8.3 ± 1.6 and 14.6 ± 1.4 points, respectively, indicating in a postoperative neurological improvement rate of approximately 91.6%. The average preoperative and final follow-up NDI scores were 12.62 ± 2.34 and 7.61 ± 1.23.ConclusionsThe sagittal parameters of patients who underwent EODL extended to C1 and C2 included loss of cervical curvature, increased cervical anteversion and compensatory posterior extension of the upper cervical spine to maintain visual balance in the field of vision. However, the changes in cervical spine parameters were far less substantial than the alarm thresholds reported in previous studies. We believe that EODL extended to C1 and C2 for the treatment of patients with spinal canal stenosis in the upper cervical spine is a feasible and safe procedure with excellent outcomes.

Hepatic Coccidiosis in Triportheus angulatus Spix & Agassiz, 1829 (Characiformes: Triportheidae), a Tropical Fish from the Eastern Brazilian Amazon, with the Description of a New Species of Calyptospora (Apicomplexa: Calyptosporidae).

Hepatic infection involving a parasite of the family Calyptosporidae was recorded in characiform fish from the Tocantins river in the Brazilian Amazon region. In the present study, an integrated comparative analysis of morphological characteristics, histological and structural traits, and the sequence of a partial fragment of the SSUrRNA gene provides support for the identification of a new calyptosporid species, found parasitising the hepatic tissue of the fish Triportheus angulatus, collected from the Tocantins River. This new species was named Calyptospora gonzaguensis n. sp. and had ovoid oocysts with a diameter of 19.6±1.4μm and four peripheral sporocysts, 9.2±0.6μm long and 3.9±0.2μm wide, enveloped individually in fine adhesive membrane, composed of an ellipsoid body and posterior extension, with a mean length of 2.2±0.4μm.

A new genus of cave spider from Neotropical region (Gnaphosidae: Prodidominae).

A new monotypic genus of Prodidominae, Indiani gen. nov., is proposed to include one cave species collected in limestone caves from Minas Gerais, Brazil: Indiani gaspar sp. nov. (♂♀). Based on a recent phylogenetic analysis of Prodidominae, the new genus is closely to other Neotropical Prodidominae, such as Lygromma, Brasilomma and Moreno by sharing a classic claw tuft clasper. Indiani gen. nov. is characterized by a ventral parallel rows of strong spines on tibia and metatarsus I-II, male palp with sclerotized conductor and the robust median apophysis is curved retrolaterally; the female epigyne has an anterior atrium and a posterior extension of the epigynal plate. As other cave Prodidominae, Indiani gen. nov. has morphological characteristics, such as loss or reduction of eyes and weak pigmentation, that indicate an adaptation for living in subterranean environments.

Kill with cold.

We describe 2 cases of fungal ciliary body granuloma, and its effective management. Case 1: A 13-year-old boy, post corneal tear repair presented with endophthalmitis with superior ciliary body granuloma [Fig. 1]. Though pars plana vitrectomy (PPV) with amphotericin-B cleared the vitreous, the granuloma persisted. Systemic fluconazole 50 mg BD (3 weeks) had no effect. Microbiologically it was dematiaceous fungi.[1] Triple freeze thaw cryotherapy was applied under direct visualization excluding iris or the retinal surface. Patient showed a good response with complete regression in 3 days [Fig. 2]. He underwent secondary intraocular lens (IOL) implantation with best-corrected visual acuity (BCVA) of 20/80 after 8 weeks.Figure 1: Black arrows show yellowish granulomas hanging from the ciliary body superiorly behind the iris with vitreous exudates and green arrow shows site of corneal tear repairFigure 2: Postop 3 months, granuloma regressed completelyCase 2: A 36-year-old lady of 6 weeks postpartum, presented with the features suggestive of endogenous endophthalmitis. She underwent PPV and was found to have retinal detachments (RD) with subretinal exudates and a large granuloma arising from the ciliary body with posterior extension [Fig. 3]. Laser around necrotic areas with silicon oil infusion was done to reattach the retina. Though the vitreous aspirate had a negative yield, we continued systemic antifungal (voriconazole 200 mg BD × 2 weeks) in view of clinical profile.[23] Since her ocular condition deteriorated with enlarging granuloma, triple freeze thaw cryotherapy was applied directly over the granuloma. The lesion regressed completely. Visual rehabilitation with scleral fixated intraocular lens (SFIOL) was done 3 months later with a BCVA of 20/200.Figure 3: Fundus image after clearing of vitreous exudates at the first surgery shows an oil filled eye and outlined area depicts location of suspected granuloma to which cryotherapy was applied laterDiscussion The fungal infection of the eye, particularly of the posterior segment is difficult to treat. They usually follow a relapsing course with recurring infiltration and exudates, ultimately leading to phthisis bulbi. Cryotherapy has been previously mentioned in literature as salvage therapy for resistant fungal infiltrates of anterior segment and transplanted cornea.[45678] We similarly applied cryo probe for 8 to 10 s [Figs. 4 and 5] and allowed it to thaw for 1 whole min before refreezing. In conclusion, fungal granuloma of the ciliary body can be safely and effectively treated with triple freeze thawing.Figure 4: (a) Fundus image of the oil filled right eye after cryotherapy was applied to suspected granuloma area shown in Figure 3. (b) Area of scarring after triple freeze thaw cryotherapy and complete resolution of the granulomaFigure 5: Demonstrates technique of triple freeze thaw cryotherapy for intraocular fungal granuloma. Cryoprobe is applied over the area of ciliary body granuloma to freeze for 8–10 s and is allowed to thaw for 1 whole min before refreezing, cycle is done totally for three timesDeclaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Active maximum flexion after total knee arthroplasty is not related to posterior tibial slope, body mass index, or patient satisfaction: A retrospective cohort study

Background: Postoperative active maximum flexion is a major contributor to effective knee function after total knee arthroplasty (TKA). The lack of posterior tibial slope and a high body mass index (BMI) have been identified among the causative factors of reduced maximum flexion. This study investigated the correlation between these factors and maximum flexion achieved. Methods: All patients included in this retrospective study had a primary navigated TKA using Columbus® CR-knee implants (Aesculap, Tuttligen, Germany) and the Orthopilot® (Aesculap, Tuttligen, Germany) navigation system. At the 6-week review patients underwent a CT. At 1 yr, active flexion was measured by independent arthroplasty practitioners, and patient satisfaction was recorded. All CT measurements were taken by an independent radiologist. Posterior slope was indicated by a positive value. Results: One hundred and eighty-six knees were included. The mean patient age was 68 yr and mean BMI was 31.0. The mean maximum active flexion at 1 yr was 103 degrees (SD 9 degrees, range, 83 to 130 degrees). The mean posterior tibial slope (bony cut) was 2 degrees (SD 2 degrees, range −2 to 5 degrees). There was no correlation between posterior tibial slope and maximum flexion, r=0.086 (95% CI −0.058 to 0.227, P=0.245) between flexion and BMI, r=−0.112 (95% CI −0.251 to 0.032, P=0.129). There was a weak correlation between posterior slope and extension achieved, r=0.198 (95% CI 0.056 to 0.332, P=0.007), but this had little clinical predictive value. There was no link between either maximum flexion or patient satisfaction. Conclusions: In this study, no relationship between posterior tibial slope or BMI and the degree of achieved active maximum flexion was found. Consequently, other factors should be considered when attempting to increase the maximum flexion achieved. Level of Evidence: Level III.

Comparative Analysis of the Therapeutic Efficiency and Radiographic Measurement Between the Transforaminal Approach and Interlaminar Approach in Percutaneous Endoscopic Discectomy.

To investigate and compare the therapeutic efficiency and radiographic measurement between the transforaminal approach and interlaminar approach in percutaneous endoscopic discectomy. From January 2017 to January 2018, 86 patients suffering from single lumbar disc herniation were included in this retrospective analysis and divided into the percutaneous endoscopic transforaminal discectomy (PETD) group and percutaneous endoscopic interlaminar discectomy (PEID) group according to different surgical approaches. Data on age, gender, course of the disease, smoking status, and body mass index (BMI) were also obtained. Moreover, lumbar spine X-ray (anterior? posterior, lateral, and excessive flexion and extension), CT scan, and MRI were performed preoperatively for all patients. Another MRI of the lumbar spine was performed within the week after the operation. Clinical efficacy was calculated to assess the clinical effect of the therapy using the visual analogue scale (VAS) and Oswestry Disability Index (ODI) at 1 day before surgery, 3 months after surgery, 1 year after surgery, and the last follow-up visit. All patients were followed up for above two year. 44 and 42 cases were enrolled, respectively, in the PETD and PEID groups. 62 males and 24 females were included in this study. The mean ages of the PETD and PEID groups were 34.58 ± 6.70 and 33.72 ± 7.12 years, respectively (p=0.763). The symptoms showed evident improvement after surgery, but there were no significant differences regarding VAS scores, ODI scores, spinal canal occupation rate and lumbar lordosis except disc height and pfirrmann grade between the two groups (p > 0.05). The revision surgery rates of the PETD and PEID groups at the last follow-up time were 2.3% and 4.8%, respectively (p=0.612). One patient in the PETD group underwent PEID revision surgery because of residual disk herniation. Re-operation were performed on 2 patients in the PEID group due to recurrencee. Approaches of the PEID and PETD are pivotal to address lumbar disc herniation (LDH) disease. Selection of surgery approach depends on anatomical structure, physiological characteristic and operative skill of the surgeon.

&lt;p class="Body"&gt;&lt;strong&gt;Complementary description of &lt;em&gt;Africoseius lativentris&lt;/em&gt; and placement of &lt;em&gt;Africoseius&lt;/em&gt; in Podocinidae (Acari, Mesostigmata) based on molecular and morphological evidences&lt;/strong&gt;&lt;/p&gt;

Morphological details of specimens collected from several localities in Brazil and identified as Africoseius lativentris (Karg 1982) are provided. The taxonomic position of Africoseius Krantz, 1962 has been debated over the years, with repeated changes in its familial placement. A phylogenetic study based on 18S and 28S rDNA sequences of the Brazilian population of A. lativentris collected at Jaboticabal, São Paulo State, and similar data of 70 taxa representing 11 families of Gamasina indicated that Africoseius is a member of the well-supported Podocinidae (sensu Lindquist et al. 2009) clade. The main morphological similarities and differences between Africoseius and the group of species until now placed in Podocinidae sensu Lindquist et al. (2009) are listed. Apomorphic characteristics uniting those taxa include the hypotrichous condition of tibia I (eight and nine setae instead of ten or more in other free-living Gamasina) and the insertions of av2 and pv2, considerably more distal on tarsi II and III than in the majority of the free-living Gamasina. Within Podocinidae, a new subfamily, Africoseiinae, is proposed, based on uniquely apomorphic characteristics of the setae ad4 and pd4 (sensu Evans 1969) of tarsi II–IV absent, and setae av4 and pv4 of same basitarsi long, incurved and close to each other and to a posterior longitudinal extension of the peripodomeric suture and on the attenuated form of the lateral (rather than the medial) hypostomatic setae. This subfamily is currently represented by Africoseius areolatus Krantz and Africoseius lativentris (Karg 1982), while all other presently known species of the family are now placed in the subfamily Podocininae.

The effect of tuning ankle foot orthoses-footwear combinations on gait kinematics of children with cerebral palsy: A case series

Study designCase series. BackgroundAFOs are a commonly prescribed medical device given to children with cerebral palsy (CP) in an attempt to improve their gait. The current literature is equivocal on the effects AFOs have on the gait of children with CP. The vast majority of AFOs issued are not subject to AFO-FC tuning. There are emerging studies investigating the effects tuning AFO-FCs has on the gait of children with CP. However, the research is limited, and there is a lack of quantitative data. ObjectiveTo compare the kinematics of tuned versus non-tuned gait in children with CP. MethodsGait analysis assessment of five children aged between 7–11 years with a diagnosis of CP (one hemiplegic and four diplegic participants, two female, three male, with a Gross Motor Functional Classification System (GMFCS) of 2) at a Gait Analysis Laboratory. ResultsIn comparison to barefoot and non-tuned gait, walking with a tuned AFO-FC produced improvements in several key gait parameters. Including hip flexion and extension, posterior pelvic tilt and knee extension. Results also indicated that the type of gait pattern demonstrated by the participant affected the outcomes of tuning. ConclusionsTuning the AFO-FC of children with CP has the potential to improve hip function, pelvic function, knee extension in stance phase and knee flexion during swing phase and that a non-tuned AFO-FC can potentially decrease hip function, posterior pelvic tilt and increase knee extension. Clinical RelevanceWhilst AFO-FC tuning has been recommended for routine clinical practice, there still remains a paucity of research on the kinematic effects of using a tuned AFO-FC compared to a non-tuned. This paper provides a comparison of kinematics on children with CP, during barefoot, non-tuned and tuned AFO-FC walking with a view to inform clinical practice.

The femoral posterior fan-like extension of the ACL insertion increases the failure load.

To examine the role of the posterior fan-like extension of the ACL's femoral footprint on the ACL failure load. Sixteen (n = 16) fresh frozen, mature porcine knees were used in this study and randomized into two groups (n = 8): intact femoral ACL insertion (ACL intact group) and cut posterior fan-like extension of the ACL (ACL cut group). In the ACL cut group, flexing the knees to 90°, created a folded border between the posterior fan-like extension and the midsubstance insertion of the femoral ACL footprint and the posterior fan-like extension was dissected and both areas were measured. Specimens were placed in a testing machine at 30° of flexion and subjected to anterior tibial loading (60mm/min) until ACL failure. The intact ACL group had a femoral insertion area of 182.1 ± 17.1mm2. In the ACL cut group, the midsubstance insertion area was 113.3 ± 16.6mm2, and the cut posterior fan-like extension portion area was 67.1 ± 8.3mm2. The failure load of the ACL intact group was 3599 ± 457N and was significantly higher (p < 0.001) than the failure load of the ACL cut group 392 ± 83N. Transection of the posterior fan-like extension of the ACL femoral footprint has a significant effect on the failure load of the ligament during anterior loading at full extension. Regarding clinical relevance, this study suggests the importance of the posterior fan-like extension of the ACL footprint which potentially may be retained with remnant preservation during ACL reconstruction. Femoral insertion remnant preservation may allow incorporation of the fan-like structure into the graft increasing graft strength.

Effect of staged exercise on rehabilitation and joint function of patients after radical mastectomy

Objective To explore the rehabilitation effect and joint effect of staged exercise on patients after radical mastectomy. Methods From November 2015 to November 2016, 134 patients who received radical mastectomy in this hospital were selected as the study subjects. According to the random number table, 67 patients were divided into the observation group and the control group. The control group was treated with routine nursing, and the observation group was treated with staged exercise.After 3 months, postoperative complications, joint function, exercise endurance and quality of life scores of the two groups of patients were observed and compared. Results Postoperative complications such as upper limb edema, joint stiffness, upper limb pain and muscle atrophy were less in the observation group (7.46%), and 25.37% in the control group, and the difference between the two groups was statistically significant(P<0.05). The social activity, psychological activity and physical function scores of the observation group were significantly higher than those of the control group 3 months after the operation, and the difference between the two groups was statistically significant(P<0.05). 3 months after the operation, the recovery of joint function in the observation group was better, with the anterior flexion, abduction, pronation, pronation, adduction and posterior extension angles significantly higher than those in the control group, and the difference between the two groups was statistically significant(P<0.05). The exercise endurance of the observation group was significantly better than that of the control group 3 months after operation, and the difference between the two groups was statistically significant (P<0.05). Conclusion Staged exercise measures have a good effect on upper limb functional rehabilitation of patients after radical resection of breast cancer, effectively reduce the incidence of complications such as pain, edema and joint stiffness on the affected side of patients, improve postoperative exercise endurance and range of motion of the patients, and have a good effect on joint rehabilitation and significantly improved quality of life. Key words: Stage exercise measures; Radical mastectomy; Rehabilitation effect; Joint effect

Analysis of the disc pressure of the upper thoracic spine using pressure-sensitive film: an experimental study in porcine model-implications for scoliosis progression.

There has been few studies focusing on the disc pressure of the upper thoracic spine and it still lacks the quantitative pressure measurement of each spinal disc segment. The aim of this study was to study the pressure changes of intervertebral disc in porcine upper thoracic spine using pressure-sensitive film. Twelve porcine thoracic motion segments were harvested and successively loaded with vertical loads of 100N, 150N, and 200N during 5° of anterior flexion, 5° of posterior extension and 5° of lateral bending. The resulting pressure values were measured. During anterior flexion, the anterior annulus of all segments at all loads showed higher mean pressure values than those during vertical compression, whereas the posterior annulus did not show higher mean values. During posterior extension, the anterior annulus of all segments showed lower mean pressure values than those during vertical compression, whereas the posterior annulus did not show lower mean pressure values. During lateral bending, the annulus of all segments showed higher mean pressure values than those during vertical compression. The posterior thoracic vertebra plays an important role in the motion of the upper thoracic vertebral segment and pressure distribution. During lateral bending, the concave side pressure of the annulus increases obviously, suggesting that asymmetrical force is a contributory factor for scoliosis progression.

Correlation between compression depth and compressive stress of the anteroposterior cervical spinal cord in different sports positions

Objective To explore the relationship between the compression depth and compressive stress of the anterior and posterior cervical spinal cord in different sports positions. Methods Specimens of ten intact fresh cervical spine (C1-T1) from adult cadaver were collected. In order to simulate cervical disc degeneration and abnormal ligamentum flavum, we placed two hemispherical steel balls into the anterior and posterior side of the cervical spinal cord through the bone window of the C4, 5. The measurement was conducted in 10%, 20%, 30%, 40%, 50%, and 60% of the sagittal diameter for the compressive stress of the anterior and posterior cervical spinal cord under different compression depths of flexion, neutral, and posterior extension. Results The anterior depth of a certain pressure with the posterior pressure depth was increasing in neutral position, the stress on the anterior of the cervical cord-meningeal complex (CCMC) had no significant change, while the stress on the posterior of the CCMC increased greatly with the increasing of the degree of canal occlusion. The stress on the posterior of the CCMC varied insignificantly between 10% and 20% depth of canal occlusion (P>0.05). However, there was remarkable significance among 30% and 60% (P 0.05). However, there was remarkable significance among 20% and 60% (P 0.05). However, there was remarkable significance among 30% and 60% (P 0.05). However, there was remarkable significance among 20% and 60% (P<0.05). The stress on the posterior of the CCMC had no significant change. Compared with the neutral position, the anterior flexion position and the posterior extension position had different trends in the compressive stress in the anterior and posterior aspect of the cervical spinal cord. Conclusion The stress on the anterior and the posterior of the CCMC has a closely nonlinear relationship with the depth of canal occlusion. With the increase of the depth of canal occlusion, the stress is increasing, especially running over the 30% depress of canal occlusion under neutral position. However, the stress is increased, especially running over the 20% depress of canal occlusion under the flexion and extension position. Key words: Spinal cord; Stress, mechanical; Posture; Biomechanics

Idiopathic Macular Hole Preferred Practice Pattern®

Idiopathic Macular Hole Preferred Practice Pattern®

Assessing autolyzed foetal brains

Problem:Evaluating very soft foetal brains is problematic, since anatomic information is often lost when these collapse on a dissection board.Methods:Present cases of very soft foetal brains photographed under water, discuss technical details on this technique, and indicate how these data can be used to evaluate the brains.Results:Foetal brains from intrauterine foetal deaths and from foetal terminations that have a long death-to-delivery time are often very soft, even after fixation, and collapse under their own weight on a dissection board. To better evaluate these brains, they have been floated and photographed in water. When possible, the brain is photographed intact in ventral and dorsal views. After the brainstem with cerebellum is removed and hemispheres are separated, these are all photographed; hemispheres are imaged in both lateral and medial views. This technique records developmental data about cortical gyration, the presence of olfactory tracts/bulbs, corpus callosum posterior extension, cerebellum foliation, and brainstem, which can be compared to standard brain development references. Problems with this technique include fragmentation of autolyzed brain into water.Discussions:Photography of very soft foetal brains under water allows evaluation of brains that normally collapse under their own weight. In cases too soft for meaningful dissection, these data often provide the only available brain developmental information.LEARNING OBJECTIVESThis presentation will enable the learner to:1.Photograph foetal brain under water2.Evaluate key aspects of external examination using standard developmental literature

Pure Mandibular Incisor Intrusion: A Finite Element Study to Evaluate the Segmented Arch Technique.

Leveling the curve of Spee is a commonly-used strategy to correct deep bites. Although several techniques have been proposed to intrude mandibular incisors (MI), flaring of these teeth is often observed and in many instances undesired. A three-dimensional (3D) finite element model (FEM) was used to locate the ideal point of force application (PFA) to achieve pure MI intrusion with the three-piece arches’ technique. It comprised (1) a 0.021 × 0.025 in. stainless steel (SS) wire that passively filled the slots of the canine and premolar brackets and the first and second molar tubes, bilaterally; (2) a 0.0215 × 0.0275 in. SS intrusion base arch (IBA) inserted into the MI brackets, that presented a step down distal to the lateral incisors brackets and a posterior extension arm; (3) titanium-molybdenum tip-back springs designed to apply the intrusion force, fitted inside the first molar gingival tube. Four PFA on the IBA were simulated (FEM 1, 2, 3, and 4). FEM 3 resulted in pure MI and was considered the ideal PFA. FEM1 and 2 showed intrusion and buccal crown flaring of the MI, whereas FEM4 resulted in intrusion and lingual crown flaring of those teeth. Clinicians may consider three-piece arch mechanics to achieve pure MI intrusion. However, they must be aware that when force was applied anteriorly or posteriorly to the ideal PFA, the incisors would incline labially or lingually, respectively.

The etiologies and prognosis associated with spinal cord infarction.

BackgroundThis study aims to investigate the etiology and prognosis of spinal cord infarction (SCI).MethodsOver a period of 16 years, we retrospectively analyzed 31 patients with SCI. Demographic features and symptom presentations were carefully documented. Etiology‐specific MRI features, such as the length and distribution of the lesions and owl’s eyes sign, were recorded and analyzed to determine their associations with the clinical signs/symptoms.ResultsIn total, seven patients had aortic or vertebral artery dissections. We divided the patients with SCI into two groups: those with or without vessel dissection. Among SCI patients, the onset age was younger, and the proportion of patients with long‐segment lesions and posterior pattern involvement on axial view was higher in the group with dissection than in the group without dissection (all P < 0.05). The lesions were frequently located in the upper cervical or lower thoracic‐lumbar regions, and the lengths of the lesions were associated with 1‐month outcomes, suggesting that artery dissection may contribute to the longitudinal and posterior extension of SCI. In contrast, among patients without dissection, the range of longitudinal extensions of in spans of vertebral bodies was broader (range, 1–8). A higher proportion of patients had focal pain adjacent to the lesion (P = 0.05) and a poorer 1‐month outcome (P = 0.04) in the long‐segment lesion group than in the short‐segment lesion group.ConclusionsA detailed history and the use of modern imaging tools may help clinicians search for vessel dissection and other etiologies, evaluate the spatial extension of lesions in SCI, and predict prognosis.

Geometric morphometrics for the analysis of character variation in size and shape of the sulcus acusticus of sagittae otolith in species of Gerreidae (Teleostei: Perciformes)

Sagittal otoliths are a useful structure to distinguish teleostean fishes. However, character variation in size and shape of the sulcus acusticus has not been tested among Gerreidae Gunther, 1862 species. For the first time, this paper explores the size and shape variation in the sulcus acusticus using landmark data and geometric morphometric methods. Variation in the sulcus acusticus size, as estimated with centroid size, is not a useful feature to distinguish neither the five genera nor all species in this study. However, since analyses of variance followed by Tukey a posteriori tests detect differences among groups of species, it is possible that the size of the sulcus acusticus will still be useful as a phylogenetic character. As expected, the pattern of variation in the shape of the sulcus acusticus consists of well-defined character states exclusive of each of the 18 species of Gerreidae included. All comparisons in multivariate analyses of variance of semi-landmark configurations with a CVA were statistically significant, and the rates for correct posterior classifications were all above 79%. Discriminant axes allowed to locate variation in particular regions of the sulcus acusticus outline that contribute most to the distinction among genera. Results revealed species in the same genus share a particular shape in the ostium and posterior extension of the cauda. Variation in the shape of the sulcus acusticus is, therefore, a very useful character to identify species in Gerreidae.

The Rate of Posterior Labral Extension In Operatively Treated Bankart Lesions

Objectives: Traumatic avulsion of the antero-inferior glenoid labrum is a well-recognized sequela of shoulder dislocation. Such Bankart lesions are readily identified on pre-operative imaging, and results of arthroscopic management of these lesion are favorable. However, the frequency with which such antero-inferior lesions propagate posteriorly remains unclear. Further, how well pre-operative imaging detects posterior labral extension remains unknown. The purpose of this study was to investigate both the rate of posterior extension in operatively managed Bankart lesions and the ability of MRI to identify such lesions prior to surgery. Methods: A retrospective review was conducted of patients undergoing operative management for a diagnosis of Bankart Lesion. All patients had a history of traumatic anterior shoulder dislocation. Patients with a history of known concomitant pathology in the ipsilateral shoulder, multi-directional instability, or prior shoulder surgery were excluded. All patients underwent a pre-operative arthrogram which was read by a trained MSK radiologist and reviewed by an orthopedic practitioner assessing for involvement of the posterior labrum. Operative dictations were then reviewed as a gold standard for posterior labral involvement. Follow up data was also reviewed to determine if posterior extension was a risk factor for post-surgical failure. Calculated rates of posterior involvement, as well as the ability of MRI arthrogram to detect posterior labral pathology were analyzed and compared via chi-squared tests. Results: Review yielded 95 shoulders with arthroscopy confirming an antero-inferior labral avulsion. Of these, 20% (19 shoulders) demonstrated involvement of the posterior labrum during arthroscopy. MRI arthrogram findings were equivalent to the arthroscopic findings 82.1% (78/95) of the time when read by a radiologist as compared to 91.6% (87/95) of the time when reviewed by a sports-trained orthopedist (p= .053). Posterior extension was detected in 8/19 (42.1%) of cases when the arthrogram was read by a radiologist alone compared to 16/19 (84.2%) of cases when the arthrogram as read by a sports-trained orthopedist (p= .007). There was no association between Bankart lesions with demonstrated posterior extension and those repairs that eventually went on to failure (p = .29). Conclusion: Propagation of a Bankart lesion into the posterior labrum is relatively common following shoulder dislocation, with data from this review demonstrating a rate of 20%. Based on our findings, careful assessment of the posterior labrum on MRI arthrogram may reveal the majority, but not all, of these lesions prior to surgery. Practitioners should maintain a high level of suspicion for posterior labral involvement, both for pre-operative planning and during operative management of traumatic shoulder dislocations.

Biomechanical Effects of Fixation of Different Segments of Goat Lumbar Spine on Adjacent Segmental Motion and Intradiscal Pressure Change.

BackgroundThe aim of this study was to investigate the biomechanical fixation effects of different segments of the goat spine on adjacent segmental motion and intradiscal pressure (IDP) change.Material/MethodsEighteen goat spine specimens were randomly divided into 3 groups: group A (single-segment fixation), group B (double-segment fixation), and group C (triple-segment fixation). The motion was tested on each specimen using a spinal motion simulation test system with rational pressure loading. The IDP was measured using a pinhole pressure sensor.ResultsRange of motion (ROM) and IDP of adjacent segments increased with increased external load. In comparison of the 3 groups, significant differences in ROM were found when the external force was more than 100 N (P<0.05). The differences in IDP of the adjacent segment were statistically significant (P<0.05) when external pressure was greater than or equal to 60 N. However, in comparison of group A with group B, no significant differences in ROM and IDP of the adjacent segments were noted for the motions of anterior flexion, posterior extension, and lateral bending (P>0.05). Moreover, upper adjacent segments had greater ROM than the lower adjacent segments (P<0.05). We found significant differences between IDPs of the upper adjacent segments and lower adjacent segments (P<0.05).ConclusionsAs the number of fixated lumbar segments increases, ROM and IDP of the adjacent segments increase. Multisegment fixation is most likely the main factor contributing to the development of adjacent segmental lesions after lumbar fixation.

A new thylacocephalan crustacean from the Upper Jurassic lithographic limestones of southern Germany and the diversity of Thylacocephala

Thylacocephala is a group of extinct eucrustaceans of presumably predatory nature. We describe here a new genus and species of thylacocephalan crustaceans from the Upper Jurassic Solnhofen limestones of Eichstatt (Altmuhltal Formation), Falcatacaris bastelbergeri n. g. n. sp. (about 150 million years old). Falcatacaris bastelbergeri n. g. n. sp. is the fourth species of Thylacocephala found in these deposits. The species differs significantly from other thylacocephalans, especially by characters of the shield. The shield of the specimen is rather low (short in dorsoventral extent) and it bears a long rostrum but no elongated posterior spine. For comparative purposes, we provide an overview of the shield morphology of known thylacocephalan species from literature as well as a morphological analysis of the group. An elliptic Fourier analysis is used to compare the different shield shapes of thylacocephalans to each other; results are presented in PCA plots. Shield length and anterior or posterior shield extensions are the characters with the most variation in thylacocephalan shield morphology.