Contribution of Elastic and Collagen Fibers to the Mechanical Behavior of Bovine Nuchal Ligament.

Ligamentum nuchae is a highly elastic tissue commonly used to study the structure and mechanics of elastin. This study combines imaging, mechanical testing, and constitutive modeling to examine the structural organization of elastic and collagen fibers and their contributions to the nonlinear stress-strain behavior of the tissue. Rectangular samples of bovine ligamentum nuchae cut in both longitudinal and transverse directions were tested in uniaxial tension. Purified elastin samples were also obtained and tested. It was observed that the stress-stretch response of purified elastin tissue follows a similar curve as the intact tissue initially, but the intact tissue shows a significant stiffening behavior for stretches above 1.29 with collagen engagement. Multiphoton and histology images confirm the elastin-dominated bulk of ligamentum nuchae interspersed with small bundles of collagen fibrils and sporadic collagen-rich regions with cellular components and ground substance. A transversely isotropic constitutive model that considers the longitudinal organization of elastic and collagen fibers was developed to describe the mechanical behavior of both intact and purified elastin tissue under uniaxial tension. These findings shed light on the unique structural and mechanical roles of elastic and collagen fibers in tissue mechanics and may aid in future use of ligamentum nuchae in tissue grafting.

Ultrasonography-based diagnosis of hemorrhage syndrome in adipose tissues in the crest of the neck of heavy horse breeds.

Hemorrhage syndrome in adipose tissues in the crest of the neck (HSCN), specifically in hemorrhagic adipose tissues on the longitudinally sectioned surface of the neck fat at the dorsal nuchal ligament, is prevalent in heavy horse breeds. Herein, we aimed to establish an ultrasonographic method to successfully diagnose HSCN in heavy horse breeds and assess its efficacy. Horses with homogeneous echogenicity images were included in the control group, whereas those with linear high-echogenicity images were classified as having HSCN. Horses with confirmed linear high-echogenicity images exhibited pathological features and significantly higher percentages of adipose tissue with hemorrhage than those observed in horses with homogeneous echogenicity images (P<0.01). Our results suggest the effectiveness of ultrasonography in identifying and diagnosing HSCN.

Duraplasty with autologous nuchal ligament fascia to reduce postoperative complications in pediatric patients undergoing neoplasia resection with a suboccipital midline approach.

OBJECTIVE: The authors sought to explore the safety and efficacy of an autologous nuchal ligament for dural repair in pediatric patients undergoing tumor resection through a suboccipital midline approach. METHODS: Pediatric patients diagnosed with posterior fossa neoplasia who underwent surgery through a suboccipital midline approach were retrospectively reviewed. The patients were divided into artificial graft and autograft groups according to whether artificial duraplasty material or autologous nuchal ligament was used to repair the dura. Postoperative complications were reviewed and analyzed, including CSF leak, pseudomeningocele, and meningitis, during hospitalization and follow-up. Univariate and multivariate logistic regression analyses were used to investigate the relationship between duraplasty material and postoperative complications, as well as other risk factors for postoperative complications. Furthermore, multinomial logistic regression analysis was used to clarify which postoperative complications the autologous nuchal ligament tended to reduce. RESULTS: This retrospective study included 66 pediatric patients who underwent tumor resection through a suboccipital midline approach. The clinical baseline characteristics were comparable between the two groups. The results showed that the autograft group had significantly fewer postoperative complications, especially pseudomeningocele, compared with the artificial graft group. Moreover, the time required to repair the dura in the autograft group was significantly less than that in the artificial graft group. Further results revealed that the duraplasty material, ependymoma, preoperative severe hydrocephalus requiring an external ventricular drain (EVD), and postoperative hydrocephalus exacerbation were independent risk factors for postoperative complications. In particular, the autologous fascia of the nuchal ligament tended to reduce pseudomeningocele more than CSF leak and meningitis. However, compared with pseudomeningocele and CSF leak, both ependymoma and postoperative hydrocephalus exacerbation were more likely to increase the occurrence of meningitis. In contrast, preoperative severe hydrocephalus requiring EVD led to increased rates of postoperative complications. CONCLUSIONS: For pediatric patients with intracranial tumors who need to undergo resection through a suboccipital midline approach, dural repair using the nuchal ligament is safe, cost-effective, and time saving and significantly reduces postoperative complications.

[Clinical effects of matrix acupuncture on cervical spondylotic radiculopathy with nuchal ligament calcification].

OBJECTIVE: To observe the effects of matrix acupuncture on the neck disability index (NDI) score, clinical efficacy, and the calcification size of the nuchal ligament in patients of cervical spondylotic radiculopathy with nuchal ligament calcification. METHODS: A total of 120 cases were randomly divided into a matrix acupuncture group and a routine acupuncture group, with 60 cases in each group. In the matrix acupuncture group, Ashi-point, bilateral Tianzhu (BL10), bilateral Fengchi (GB20), bilateral Dazhu (BL11), bilateral Jianzhongshu (SI15), and Jianjing (GB21), Tianzong (SI11), Quchi (LI11), Shousanli (LI10), Waiguan (TE5), and Hegu (LI4) at the affected side were selected. In the routine acupuncture group, C3-C7 Jiaji points at the neck and Jianjing (GB21), Tianzong (SI11), Quchi (LI11), Shousanli (LI10), Waiguan (TE5), Hegu (LI4), and Ashi-point at the affected side were selected. The patients in the two groups were treated 30 min once, six days a week, for a total of four weeks. The NDI scores, clinical efficacies, and calcification sizes of nuchal ligament were compared between the two groups every wee-kend. RESULTS: After four weeks of treatment, the NDI scores and calcification volumes of nuchal ligament decreased in both groups (P<0.05). Compared with the routine acupuncture group, the matrix acupuncture group showed decreased NDI scores and reduced calcification volumes of nuchal ligament at the 1st, 2nd, 3rd, and 4th weeks of treatment (P<0.05). The cure and marked effective rate in the matrix acupuncture group at the 2nd, 3rd, and 4th weeks of treatment were superior to those of the routine acupuncture group (P<0.05). CONCLUSION: The matrix acupuncture group and the routine acupuncture group are effective in reducing the NDI score and calcification size of nuchal ligament in patients of cervical spondylotic radiculopathy with nuchal ligament calcification. However, matrix acupuncture has obvious advantages over routine acupuncture.

Morphometrics of nuchal ligament in greyhound in different neck and body positions.

This study was conducted to describe the morphometrics of nuchal ligament and investigate the effects of different neck and body positions on the nuchal ligament in greyhounds. Nine adult greyhounds cadavers without any locomotion abnormalities were dissected through the neck musculature on the left side to expose the nuchal ligament. Three pins were placed to mark regions of interest on the nuchal ligament: at one cm cranial to the site of origin (the most dorsal point of the spinous process of the first thoracic vertebra), at the midpoint of the nuchal ligament and one cm caudal to the nuchal ligament site of insertion (close to the caudal aspect of the spinous process of the axis). Each cadaver was positioned on a masonite board and placed on a table on the floor in their lateral recumbency and seven different standardized body positions; P1-P7 were mimicked using goniometers and metal wires. Photographs were taken by positioning and fixing the camera above the nuchal ligament region. The length and widths (W1, W2 and W3) of nuchal ligament were measured using Image Pro software (Image-Pro Express version 5.0) on standardized photographs of each of seven different body and neck positions. The length of nuchal ligament in relation to the neutral position (P1) was less (- 7%, p > 0·05) in P6 (neck elevated) and increased in all other positions (+1%, p > 0·05 for P2, +19%, p < 0·05 for P3, +37%, p < 0·05 for P4, +1%, p > 0·05 for P5, +40%, p < 0·05 for P7). Nuchal ligament width at the middle (W2) decreased significantly with P4 (- 26%, p < 0·05), and P7 (- 32%, p < 0·05). Also, nuchal ligament width at the site of origin (W3) decreased significantly with P4 (- 24%, p < 0·05) and P7 (-35%, p < 0·05). These findings reflect the need for clinical and biomechanical studies to describe in-depth the gross anatomy of the nuchal ligament in greyhounds. They suggest that different neck and body positions change the shape, and hence, the function of the nuchal ligament during movement.

Effectiveness of nuchal ligament autograft in the healing of an experimental superficial digital flexor tendon defect in equid.

This study aimed to investigate nuchal ligament (NL) autograft on experimental tendon defect healing in donkeys. Eight healthy donkeys were used. The left forelimb's superficial digital flexor (SDF) tendon was assigned as treatment, and the right forelimb was allocated as the control group (without surgical intervention). A 3×1.5 cm segment of the funicular part of the NL was excised. A full thickness defect created in the treatment tendon and was grafted with the excised NL. The following parameters were evaluated in 120 days postoperatively: clinical, ultrasonography, radiography, histopathology, biomechanical properties, and scanning and electronic transmission microscopy. There were no significant changes observed in the neck angle so that it was confirmed this treatment regimen preserved the head and neck situation without any considerable neck swelling. Weight-bearing in gait and trot was similar between both forelimbs at the end of the study. Mild to moderate adhesion was detected in the dorsal surface of the SDF tendon. There was no significant difference in the echogenicity and fiber alignment, respectively, on days 90 and 120 after surgery. Treatment significantly amplified the collagen diameter and enhanced the collagen fibril diameter and density considerably compared to the NL. The transplanted tissue was mostly in the remodeling or maturation phase, on day 120 postoperatively. It seems that the NL is biocompatible, almost biodegradable, and effective in tendon healing without metaplasia or tissue rejection.

Spinal ligamentous injury in abusive head trauma: a pictorial review.

There is growing evidence of spine injury in abusive head trauma (AHT). Historically, spine injury was considered rare in AHT because of a lack of attributable clinical symptoms or signs and a lack of advanced imaging. Increased use of MRI in AHT has been instrumental in helping identify evidence of ligamentous injuries of the spine. These findings can be difficult to identify on autopsy because of the size and location of the ligaments. Because spinal injury in AHT mostly involves ligamentous and soft tissues and only rarely involves bony fractures, more than 90% of the injury findings are missed on CT or radiography of the spine. Investigation of these findings and the injury patterns should lead to a better understanding of the mechanism of spinal injury. In this pictorial review, we describe the various manifestations of spinal ligamentous injury in AHT, as seen on MRI, in children younger than 48 months.

Potential Link between Ossification of Nuchal Ligament and the Risk of Cervical Ossification of Posterior Longitudinal Ligament: Evidence and Clinical Implication from a Meta-Analysis of 8429 Participants.

OBJECTIVE: The aim of the present paper was to evaluate the strength and the magnitude of the association between ossification of the nuchal ligament (ONL) and the risk of cervical ossification of the posterior longitudinal ligament (COPLL) and to determine whether there is a direct association or whether COPLL is a consequence of shared risk factors. METHODS: Medline, Web of Science, Cochrane Library, and Embase databases were searched for studies evaluating the association of COPLL-ONL published before July 2020. Eligible studies were selected based on certain inclusion and exclusion criteria. Two investigators independently conducted the quality assessment and extracted the data, including study designs, countries, patients' age, gender, body mass index (BMI), and the risk of COPLL between individuals with and without ONL. A meta-analysis of homogenous data, a sensitivity analysis, a publication bias assessment, and a subgroup analysis were performed using Stata 12.0 software. RESULTS: A total of 10 cohort studies involving 8429 participants were incorporated into this analysis. Pooled results demonstrated a statistically significant association between the presence of ONL and the increased COPLL risk (odds ratio [OR] 3.84; 95% confidence interval [CI] 2.68-5.52, P < 0.001). Furthermore, subgroup analyses indicated that this association was independent of study design (6.36-fold in case-control studies vs 3.22-fold in cross-sectional studies), sex (6.33-fold in male-female ratio >2.5 vs 2.91-fold in male-female ratio <2.5), age (4.28-fold in age ≥55 years vs 3.45-fold in age <55 years), and BMI (3.88-fold in BMI ≥ 25 kg/m2 vs 2.43-fold in BMI < 25 kg/m2 ), which also indicated that obese, older male patients with ONL had a higher risk of OPLL. Moreover, combined two articles revealed that patients with larger-type ONL had a significantly higher risk of long-segment COPLL compared with controls (OR 1.86; 95% CI 1.41-2.47, P < 0.001). CONCLUSION: This is the first meta-analysis to demonstrate a strong and steady association between ONL and higher risk of COPLL. This association was independent of sex, age, and BMI. Considering that ONL is generally asymptomatic and easily detectable on X-ray, our findings implied that ONL might serve as an early warning sign of the onset of COPLL and provide clinicians an opportunity for early detection and early intervention.

An in situ and ultrasound study of Yonaguni ponies revealed the rare finding of the nuchal ligament lamellae from C2-C7.

The Yonaguni pony is a rare breed of pony that has remained isolated on the westernmost island of Japan and may well retain normal morphological traits currently lost in most domestic horses (Equus caballus), such as the attachment of the nuchal ligament lamellae (NLL) from C2-C7. Recent research has found that NLL attachments are no longer present at C6 and C7 in most modern domesticated horses. This study investigated the attachments of the NLL in three Yonaguni ponies; 2 were examined in situ(deceased), and 1 was examined in vivo via ultrasound. The aim was to verify the attachments and compare the morphology to that in equids from previous studies. The in situ (2/2) and in vivo (1/1) findings revealed that the NLL was attached from C2-C7 in the Yonaguni ponies.

Description and etiology of paleopathological lesions in the type specimen of Parasaurolophus walkeri (Dinosauria: Hadrosauridae), with proposed reconstructions of the nuchal ligament.

Paleopathology, or the study of ancient injuries and diseases, can enable the ecology and life history of extinct taxa to be deciphered. Large-bodied ornithopods are the dinosaurs with the highest frequencies of paleopathology reported to-date. Among these, the crested hadrosaurid Parasaurolophus walkeri is one of the most famous, largely due to its dramatic elongated and tubular nasal crest. The holotype of Parasaurolophus walkeri at the Royal Ontario Museum, Canada, displays several paleopathologies that have not been discussed in detail previously: a dental lesion in the left maxilla, perhaps related to periodontal disease; callus formation associated with fractures in three dorsal ribs; a discoidal overgrowth above dorsal neural spines six and seven; a cranially oriented spine in dorsal seven, that merges distally with spine six; a V-shaped gap between dorsal spines seven and eight; and a ventral projection of the pubic process of the ilium which covers, and is fused with, the lateral side of the iliac process of the pubis. These lesions suggest that the animal suffered from one or more traumatic events, with the main one causing a suite of injuries to the anterior aspect of the thorax. The presence of several lesions in a single individual is a rare observation and, in comparison with a substantial database of hadrosaur paleopathological lesions, has the potential to reveal new information about the biology and behavior of these ornithopods. The precise etiology of the iliac abnormality is still unclear, although it is thought to have been an indirect consequence of the anterior trauma. The discoidal overgrowth above the two neural spines also seems to be secondary to the severe trauma inflicted on the ribs and dorsal spines, and probably represents post-traumatic ossification of the base of the nuchal ligament. The existence of this structure has previously been considered in hadrosaurs and dinosaurs more generally through comparison of origin and insertion sites in modern diapsids (Rhea americana, Alligator mississippiensis, Iguana iguana), but its presence, structure, and origin-attachment sites are still debated. The V-shaped gap is hypothesized as representing the point between the stresses of the nuchal ligament, pulling the anterior neural spines forward, and the ossified tendons pulling the posterior neural spines backward. Different reconstructions of the morphology of the structure based on the pathological conditions affecting the neural spines of ROM 768 are proposed. Finally, we review the history of reconstructions for Parasaurolophus walkeri showing how erroneous misconceptions have been perpetuated over time or have led to the development of new hypotheses, including the wide neck model supported in the current research.

Anatomy and clinical relevance of sub occipital soft tissue connections with the dura mater in the upper cervical spine.

BACKGROUND: The upper cervical region is a complex anatomical structure. Myodural bridges between posterior suboccipital muscles and the dura might be important explaining conditions associated with the upper cervical spine dysfunction such as cervicogenic headache. This cadaver study explored the upper cervical spine and evaluated the myodural bridges along with position of spinal cord in response to passive motion of upper cervical spine. METHODS: A total of seven adult cadavers were used in this exploratory study. The suboccipital muscles and nuchal ligament were exposed. Connections between the Rectus Capitis Posterior major/minor and the Obliquus Capitis minor, the nuchal ligament, posterior aspect of the cervical spine, flavum ligament and the dura were explored and confirmed with histology. The position of the spinal cord was evaluated with passive motions of the upper cervical spine. OUTCOMES: In all cadavers connective tissues attaching the Rectus Capitis Posterior Major to the posterior atlanto-occipital membrane were identified. In the sagittal dissection we observed connection between the nuchal ligament and the dura. Histology revealed that the connection is collagenous in nature. The spinal cord moves within the spinal canal during passive movement. DISCUSSION: The presence of tissue connections between ligament, bone and muscles in the suboccipital region was confirmed. The nuchal ligament was continuous with the menigiovertebral ligament and the dura. Passive upper cervical motion results in spinal cord motion within the canal and possible tensioning of nerve and ligamentous connections.

Evaluating Ultrasound as a Noninvasive Technique for Investigating Anatomical Variations of the Equine Nuchal Ligament Lamellae.

Ultrasound is a well-established modality in equine investigative and diagnostic procedures. Although to date, it has not been utilized in examining the attachments of the equine nuchal ligament lamellae (NLL) onto the cervical vertebrae, for which a noninvasive technique is currently lacking. This study presents a standardized methodology for investigating the equine NLL using ultrasonography, and further evaluates the ultrasound images against postmortem dissection in two nonrelated horses. The ultrasound images in both horses clearly presented the attachment points of the NLL to the dorsal spines of the cervical vertebrae from C2 to C5, whereas no attachment points could be seen from C6 to C7. The ultrasound images were confirmed through close, comparative inspection of the NLL postmortem. Therefore, ultrasound provides a noninvasive alternative to gross anatomic dissections for investigating the NLL attachments in members of the family Equidae. Importantly, this provides an opportunity to examine endangered breeds or isolated populations without the detrimental loss to the gene pool of rare anatomic and or primitive traits.

Rare Finding of a Full Nuchal Ligament Lamellae With Attachment Points From C2-C7 in One Australian Stock Horse.

For over 200 years, equine anatomic literature has chiefly portrayed the attachment points of the nuchal ligament lamellae (NLL) from the second to the seventh cervical vertebrae (C2-C7). However, recent studies have shown that the modern domestic horse, Equus caballus, primarily exhibits the attachments points from C2-C5. Here we present the rare finding of a complete NLL attached from C2-C7 in one Australian Stock Horse (ASH) and discuss the potential implications of these findings. Previously, this trait has only been confirmed among close descendants of Equus ferus ferus; namely the primitive Dutch Konik and Bosnian Mountain Horse. The examination of the NLL attachment points in 55 unrelated horses of mixed breeds revealed that 52 horses had attachments from C2-C5; 1 horse (Welsh Cob) had attachments from C2-C6; and only 2 horses (ASH and Dutch Konik) presented with a complete NLL attached from C2-C7. In light of earlier findings that suggest this loss of NLL attachment at C6 and C7 occurred after domestication, a possible explanation for this finding in 1 ASH is that it is a remnant trait from the founder population of Waler horses that contributed to the early development of the ASH breed. The reported rare occurrence of a complete NLL (C2-C7) in a modern domesticated equine (ASH) suggests that there may be other individuals expressing this unique trait, providing opportunity for its preservation.

Imaging analysis of ossification of the nuchal ligament with cervical curvature and segmental stability / 中国组织工程研究

BACKGROUND: In degenerative cervical spondylosis associated with cervical curvature straightening or segmental instability, ossification of the nuchal ligament caused by chronic injury of the nuchal ligament is very common. OBJECTIVE: To investigate the correlation between ossification of the nuchal ligament and cervical curvature and segmental stability of the cervical spine. METHODS: Data of 109 patients with degenerative cervical spondylosis, who were treated in Department of Spinal Surgery of Affiliated Hospital of Xuzhou Medical University from October 1, 2017 to October 31, 2018, were retrospectively analyzed. There were 61 male patients and 48 female patients, who aged 30 to 81 years old at a mean age of (55. 8±11. 1) years. All patients signed the informed consent. This study was approved by the Ethics Committee of Affiliated Hospital of Xuzhou Medical University. The patients underwent the X-ray examinations of cervical spine. The imaging observation included the distribution and degree of ossification of the nuchal ligament and the change of cervical physiological curvature and segment stability. The patients were divided into ossification group and non-ossification group according to whether or not the patients had ossification of the nuchal ligament. Gender, age, cervical curvature and lower cervical stability were compared between the two groups. Pearson correlation analysis was used to compare the relationship between the degree of ossification of the nuchal ligament and cervical curvature and cervical stability. Binary Logistic regression analysis was applied to evaluate the significant risk factors for the development of ossification of the nuchal ligament. RESULTS AND CONCLUSION: (1) Of 109 patients with degenerative cervical spondylosis, 56 patients with ossification of the nuchal ligament and ossification involved 83 cervical segments in ossification of the nuchal ligament patients, most of which were C4-5 (39. 8%) and Cm (42. 2%). (2) There was significant difference in age, C2-C7 Cobb angle, Jackson physiological stress curve, parameter angular displacement and horizontal displacement between the ossification group and non-ossification group (P < 0. 05). The degree of ossification of the nuchal ligament was positively correlated with angular displacement (f=0. 486, P < 0. 05). (3) The incidence of ossification of the nuchal ligament was significantly higher in patients with lower cervical instability (P < 0. 05). Age and lower cervical instability parameter angular displacement were significant risk factors for the development of ossification of the nuchal ligament. (4) Patients with ossification of the nuchal ligament are more likely to have cervical curvature straightening and lower cervical instability, especially in the segment instability. In the diagnosis and treatment of degenerative cervical spondylosis, the existence of ossification of the nuchal ligament causes corresponding attention.

Bovine cervical bursitis co-infection caused by Brucella abortus and Onchocerca sp.

The presence of Onchocerca guturosa in cattle is responsible for lesions similar to those observed in cases suspected of brucellosis, however, Onchocerca sp. is not a trade barrier, although it is also responsible for economic losses due to the removal of the affected parts of the carcasses. Brucella sp. is a zoonotic agent transmitted to humans through the consumption of contaminated animal products, the contact with infected animals and the handling of carcasses. This agent is also responsible for non-tariff trade barriers. Cervical bursitis is Brucella sp. suggestive lesions in bovine carcasses that requires laboratory tests to confirm the diagnosis. The objective of this study was to record the co-infection of Brucella abortus and Onchocerca sp. as a first report of co-infection of these two agents in the same lesion. The sample constituted of a nuchal bursitis in the cervical ligament, a suggestive lesion common to these two agents, submitted to histopathology and Brucella spp. isolation in the Brucellosis reference laboratory of the Brazilian Ministry of Agriculture, Livestock and Food Supply. Brucellosis serological diagnosis were also performed in the animal's serum sample. B. abortus was isolated from the lesion and filarid nematode structures were identified in histopathology. All serological tests were positive for brucellosis. Further studies are needed, however, to understand the co-infection by Onchocerca sp. and B. abortus.

An equine cadaver study investigating the relationship between cervical flexion, nuchal ligament elongation and pressure at the first and second cervical vertebra.

Pressure in the atlanto-axial region due to hyperflexion ('rollkur') may influence the development of a nuchal bursa, as adventitious bursae may be caused by pressure. Investigating the pressure between the nuchal ligament and atlas/axis in a flexed position may provide information on the pathogenesis of nuchal bursitis. In this study, ten equine head and neck specimens with one side of the soft tissues over the cervical vertebral spine removed were placed in lateral recumbency on a table in neutral, mildly flexed, and hyperflexed head and neck positions. Angulations of the neck were measured using markers placed on the nuchal ligament and drilled into the skull, vertebrae and withers. In six specimens, the pressure between the nuchal ligament and the atlas and the axis was measured using an inflatable air pouch. Hyperflexion was associated with the highest nuchal ligament length and with the highest pressure values at the site of the nuchal bursa over the atlas (99±24mmHg, more than four times the pressure in the neutral position) and over the axis (77±30mmHg, more than twice the pressure values of the neutral position). Also, over the three head and neck positions, neck flexion angles were highly correlated with pressure values and with nuchal ligament length. This marked increase in pressure at the level of atlas and axis caused by head and neck hyperflexion should be considered during training of horses at risk of, or diagnosed with, nuchal bursitis.

B-mode ultrasonography and gray scale histogram for evaluation of the nuchal ligament in Quarter horse / Ultrassonografia modo-B e histograma em escala de cinza para avaliação do ligamento nucal em equinos da raça Quarto de Milha

The gray scale histogram (GSH) makes it possible to measure the amount and distribution of gray shade frequencies, providing quantitative information on both echogenicity and echotexture of tissues. There is a need to diminish the subjectivity of the ultrasound images of the nuchal ligament (NL). This work proposes to evaluate the NL by ultrasound B-mode GSH images in different ages of Quarter horses. It used 15 healthy Quarter horses, which were classified by age into three different groups: "baby" (1), "sobreano" (2) and "adult" (3). The animals were submitted to chemical restraint for the ultrasound examination. Subsequently, the GSH tool was used in each image for statistical analysis. There was a significant difference between Mean and Mode between groups. Group 1 differed significantly when compared to Group 2 and 3. Group 2 presented superior echogenicity to Group 1 and 3. The height of the NL did not vary considerably between groups. GSH indicated that the echogenicity of NL in Quarter horses varies with age.(AU)

O histograma em escala de cinza (HEC) possibilita a mensuração da quantidade e distribuição da frequência de tonalidades de cinza, fornecendo informações quantitativas, tanto sobre a ecogenicidade quanto a ecotextura dos tecidos. Havendo a necessidade de diminuir a subjetividade das imagens ultrassonográficas do ligamento nucal (LN), esse trabalho propôs avaliar o LN por imagens ultrassonográficas modo-B pelo HEC em diferentes idades de cavalos da raça Quarto de Milha. Utilizou 15 cavalos da raça Quarto de Milha saudáveis os quais foram classificados por idade em três grupos diferentes: "baby" (1), "sobreano" (2) e "adulto" (3). Os animais foram submetidos a contenção química para a realização do exame ultrassonográfico. Posteriormente, a ferramenta HEC foi empregada em cada imagem para análise estatística. Houve diferença significativa entre as variáveis "Mean" e "Mode" entre os grupos. O Grupo 1 diferenciou significativamente quando comparado ao Grupo 2 e 3. O Grupo 2 apresentou ecogenicidade superior ao Grupo 1 e 3. Quanto à altura do LN não teve variação considerável entre os grupos. O HEC indicou que a ecogenicidade do LN em cavalos Quarto de Milha varia conforme a idade.(AU)

Radiographic analysis of the correlation between ossification of the nuchal ligament and sagittal alignment and segmental stability of the cervical spine in patients with cervical spondylotic myelopathy.

BACKGROUND: Ossification of the nuchal ligament (ONL) caused by chronic injury to the nuchal ligament (NL) is very common in instability-related cervical disorders. PURPOSE: To determine possible correlations between ONL, sagittal alignment, and segmental stability of the cervical spine. MATERIAL AND METHODS: Seventy-three patients with cervical spondylotic myelopathy (CSM) and ONL (ONL group) and 118 patients with CSM only (control group) were recruited. Radiographic data included the characteristics of ONL, sagittal alignment and segmental stability, and ossification of the posterior longitudinal ligament (OPLL). We performed comparisons in terms of radiographic parameters between the ONL and control groups. The correlations between ONL size, cervical sagittal alignment, and segmental stability were analyzed. Multivariate logistic regression was used to identify the independent risk factors of the development of ONL. RESULTS: C2-C7 sagittal vertical axis (SVA), T1 slope (T1S), T1S minus cervical lordosis (T1S-CL) on the lateral plain, angular displacement (AD), and horizontal displacement (HD) on the dynamic radiograph increased significantly in the ONL group compared with the control group. The size of ONL significantly correlated with C2-C7 SVA, T1S, AD, and HD. The incidence of ONL was higher in patients with OPLL and segmental instability. Cervical instability, sagittal malalignment, and OPLL were independent predictors of the development of ONL through multivariate analysis. CONCLUSION: Patients with ONL are more likely to have abnormal sagittal alignment and instability of the cervical spine. Thus, increased awareness and appreciation of this often-overlooked radiographic finding is warranted during diagnosis and treatment of instability-related cervical pathologies and injuries.

Radiographic Features and Correlation Analysis of Location of Ossification in Patients with Cervical Ossification of the Posterior Longitudinal Ligament Combined with Ossification of the Nuchal Ligament.

OBJECTIVE: To investigate the incidence, distribution characteristics, and radiographic features of the ossification of the posterior longitudinal ligament (OPLL) combined with ossification of the nuchal ligament (ONL) and to analyze the correlation between the location of ONL and degree of ossification in patients with cervical OPLL. METHODS: From January 2010 to December 2016, the clinical data of 217 patients with cervical OPLL were reviewed retrospectively. Type and location of OPLL and ONL were determined on computed tomography images and lateral radiograph films. For patients with the local type of ONL, the segment with the largest spinal canal occupation ratio (COR) of OPLL was determined on cross-sectional computed tomography slices. The correlation between the location of ONL and segment with the largest COR of OPLL was evaluated. RESULTS: Of the 217 patients with cervical OPLL, 118 patients (54.4%) had OPLL combined with ONL (92 male and 26 female patients). The incidence of ONL was almost 1.4 times greater in males than in female patients (P = 0.03). C5-C6 (49.5%) was the segment at which ONL occurred most. Of 60 patients with the local type of ONL, 34 patients' ONL was located at the segment with largest COR of OPLL. The matching ratio was the largest (77.8%) when the type of OPLL was locally circumscribed (P = 0.003). CONCLUSIONS: The incidence of ONL was 54.4% in patients with cervical OPLL, and male patients were affected more than female patients. ONL occurred most in segment C5-C6. The location of local-type ONL commonly corresponded to the segment with the largest COR of OPLL when type of OPLL was circumscribed.