Palpable Anatomical Landmarks Research Articles

A Safe Corridor using Palpable Anatomical Landmarks to Avoid Injury to Common Peroneal Nerve – A South Indian Cadaveric Study

Background: Surgeries involving the proximal third of the fibula are associated with the risk of common peroneal nerve (CPN) injury. Hence, a safe corridor using palpable anatomical landmarks is necessary to avoid injury to the CPN. Methodology: Sixty lower limbs (30 fresh cadavers) were in our study group. The distance between the Gerdy's tubercle (GT) and the CPN behind the fibular head (FH), distance from GT to the superficial branch of the CPN (superficial peroneal nerve [SPN]), and distance from GT to the anterior recurrent branch of the CPN (anterior tibial recurrent nerve [ATRN]) were measured, and a safe zone to avoid CPN injury was identified. Results: The distance between the GT and the CPN behind the FH was 45.52 ± 2.4 mm, distance from GT to the origin of the SPN was 46.44 ± 2.4 mm, and distance from GT to the ATRN was 45.59 ± 2.9 mm. Conclusion: The safe corridor to avoid CPN injury is identified by an arc trajectory with a radius of 45.85 mm with the GT as the center, which will be useful during surgical procedures to avoid injury to the CPN.

Vulvar anatomy relevant to vaginal surgery

The objective of this video is to systematically review components of vulvar anatomy for learners, and to review standardized anatomical terms, based on Terminologia Anatomica and prior findings from the Society for Gynecologic Surgeons Pelvic Anatomy Group. The video illustrates on a patient some of the key vulvar anatomic landmarks and reviews some relevant clinical correlates of these structures. Palpable anatomic landmarks are demonstrated. Throughout the video we emphasize preferred and non-preferred terms for each anatomic structure. This video can be used by learners at all stages of clinical education to review relevant vulvar anatomy and appropriate terminology prior to vaginal surgical procedures.

Does ultrasound-guidance improve the outcome of botulinum toxin injections in cervical dystonia?

PurposeUltrasound-guided injections of botulinum neurotoxin in cervical dystonia have a number of theoretical advantages. However, their action has never been compared to that of non-guided injections. The objectives of the study were to compare the outcome of botulinum neurotoxin type A treatment in patients with idiopathic, focal cervical dystonia, according to two methods: inspection and palpation of anatomical landmarks (non-guided group) or ultrasound guidance (ultrasound-guided group). MethodsWe included consecutive patients in this single-center, prospective, real-life, non-randomized study. The outcomes were evaluated one month after the injections: Cervical Dystonia Impact Profile 58 (main outcome), Toronto Western Spasmodic Torticollis Rating Scale-2 (pain and disability subscores), Toronto Western Spasmodic Torticollis Rating Scale-PSYCH, patient-rated Clinical Global Impression - Improvement and adverse events. We used propensity score methods for statistical analysis; ten predefined confounding factors were used to build the propensity score. ResultsSixty-three patients were included in the non-guided group, and 60 other patients in the ultrasound-guided group. We found no difference in main and secondary outcomes between the two study groups. ConclusionThis is the first direct comparison between ultrasound-guided and non-guided botulinum neurotoxin type A injections in patients with cervical dystonia. We hypothesize that ultrasound guidance made it possible to obtain the same results in the most severe (or the most demanding) patients as in the best responders. Further studies are still needed to assess the impact of botulinum neurotoxin injections into deep cervical muscles.

Ease of lumbar epidural catheter insertion with prepuncture ultrasound as guidance compared with conventional palpatory technique when performed by anesthesiology residents: A randomized controlled trial.

Background and Aims:Lumbar epidural catheter insertion is conventionally performed by anesthesia residents by palpation of anatomical landmarks with relatively blind localization of epidural space which may lead to an increase in failure rate. We aim to compare the ease of lumbar epidural catheterization using prepuncture ultrasound as guidance with that of conventional palpatory technique. Comparisons were made with reference to number of insertion attempts, total time taken for the procedure, frequency of dural puncture, and overall satisfaction score as assessed by Likert's scale.Material and Methods:Eighty, ASA 1-3, patients undergoing elective surgeries requiring lumbar epidural catheterization were recruited for the study. Study participants were randomized into two groups. In group P, epidural catheterization was performed using the conventional palpatory method and in group U, it was performed with the help of ultrasound determined parameters. Number of insertion attempts, total time taken for successful insertion of epidural catheter, frequency of dural puncture, and overall satisfaction of ease of insertion as determined by Likert's scale were compared between both the groups. Data were analyzed using SPSS statistical software version 17 and P value <0.05 was considered statistically significant.Results:The number of insertion attempts was significantly lesser in Group U (P = 0.019). The total procedure time was significantly higher in group U (P < .001). There was no significant difference in ease of insertion score, as measured by Likert's scale between both the groups (P = 0.45).Conclusion:Prepuncture ultrasound guidance improves the first attempt success rate of lumbar epidural catheterization with reduced incidence of dural puncture with similar overall satisfaction score but increases the total time taken for the procedure when compared to conventional palpatory technique.

Accuracy of non-guided versus ultrasound-guided injections in cervical muscles: a cadaver study.

The col-cap concept encouraged neurologists to inject a large group of muscles in the treatment of cervical dystonia. This includes deep muscles such as the obliquus capitis inferior or the semispinalis capitis, and muscles close to vascular or neurological structures such as scalene muscles. Our aim was to determine the accuracy of injections in cervical muscles using ultrasonography (US) or palpation of anatomical landmarks. A mix of paint, gelatin and iodized contrast agent was injected in nine pairs of cervical muscles of human cadavers, according to two injection techniques: US-guided and non-guided. The dye was localized on 1cm-thick, frozen slices. A total of 102 muscles was injected in the US-guided group (n = 8). The global accuracy was 88.2%. The lowest accuracy was in the OCI (41.7%); trying to avoid the vertebral artery, injections were too medial. A total of 54 muscles was injected in the non-guided group (n = 3). The global accuracy was 48.0%; moreover, some dye was found in four blood vessels. The embalming process produced texture changes, making difficult the palpation of bony landmarks. Our results indicate that US-guided injections are more accurate than non-guided injections in most cervical muscles.

A strathclyde cluster model for gait kinematic measurement using functional methods: a study of inter-assessor reliability analysis with comparison to anatomical models

A major source of error in reliability of gait analysis arises from the palpation of anatomical landmarks (ALs). The purpose of this study was to investigate whether less reliance on manually identifying ALs could improve inter-assessor reliability of joint kinematics compared to two anatomical models. It was hypothesised that the Strathclyde functional cluster model (SFCM), in which the hip, knee and ankle joint centres and knee and ankle flexion axes were determined by functional methods, would obtain greater inter-assessor reliability. Ten able-bodied participants and seven assessors were recruited. Each participant completed three trials conducted by different assessors on non-consecutive days. Agreement and inter-assessor reliability between the models were compared and analysed, whilst factor effects of assessor experience and body mass index (BMI) were investigated. The SFCM obtained excellent agreement with anatomical models for all sagittal angles and hip ab/adduction angle, and it showed slightly higher inter-assessor reliability with smaller variations in the knee and ankle. The assessor experience was not a significant factor, but the BMI had a significant effect on the inter-assessor reliability. The results demonstrate that the SFCM may be more beneficial for less experienced assessors.

Ultrasonographic Characteristics of the Stifle Joint in Clinically Normal Donkeys (Equus asinus)

Stifle ultrasonography is a widely accepted diagnostic tool that has been used for diagnosing articular and peri-articular stifle injuries in horses. Limited information is available regarding the ultrasonographic appearance of the stifle joint in donkeys. The aim of the present study was to describe the normal ultrasonographic characteristics of the stifle joint in clinically normal donkeys. A descriptive study was done on 15 clinically normal donkeys (30 joints). Ultrasonographic examination was done in a systematic manner including both supra- and infra-patellar regions. The patella, patellar ligaments and tibial tuberosity were taken as palpable anatomical landmarks for localization of different stifle structures. A detailed description of the ultrasonographic appearance of the quadriceps muscle, supra-patellar pouch and femoropatellar joint was done through the supra-patellar approach. In infra-patellar approach, thepatellar ligaments, medial and lateral femorotibial joints, collateral ligaments, menisci, origin of peroneous tertius and popliteal tendon were described. Standardized, repeatable and reliable images were achieved from both approaches. Ultrasonography provided a clinically useful tool for diagnosing donkeys with stifle joint disease.

Upper limb joint kinematics using wearable magnetic and inertial measurement units: an anatomical calibration procedure based on bony landmark identification

The estimate of a consistent and clinically meaningful joint kinematics using wearable inertial and magnetic sensors requires a sensor-to-segment coordinate system calibration. State-of-the-art calibration procedures for the upper limb are based on functional movements and/or pre-determined postures, which are difficult to implement in subjects that have impaired mobility or are bedridden in acute units. The aim of this study was to develop and validate an alternative calibration procedure based on the direct identification of palpable anatomical landmarks (ALs) for an inertial and magnetic sensor-based upper limb movement analysis protocol. The proposed calibration procedure provides an estimate of three-dimensional shoulder/elbow angular kinematics and the linear trajectory of the wrist according to the standards proposed by the International Society of Biomechanics. The validity of the method was assessed against a camera-based optoelectronic system during uniaxial joint rotations and a reach-to-grasp task. Joint angular kinematics was found as characterised by a low-biased range of motion (<−2.6°), a low root mean square deviation (RMSD) (<4.4°) and a high waveform similarity coefficient (R2 > 0.995) with respect to the gold standard. Except for the cranio–caudal direction, the linear trajectory of the wrist was characterised by a low-biased range of motion (<11 mm) together with a low RMSD (8 mm) and high waveform similarity (R2 > 0.968). The proposed method enabled the estimation of reliable joint kinematics without requiring any active involvement of the patient during the calibration procedure, complying with the metrological standards and requirements of clinical movement analysis.

Pelvis and femur shape prediction using principal component analysis for body model on seat comfort assessment. Impact on the prediction of the used palpable anatomical landmarks as predictors.

A personalized pelvis and femur shape is required to build a finite element buttock thigh model when experimentally investigating seating discomfort. The present study estimates the shape of pelvis and femur using a principal component analysis (PCA) based method with a limited number of palpable anatomical landmarks (ALs) as predictors. A leave-one-out experiment was designed using 38 pelvises and femurs from a same sample of adult specimens. As expected, prediction errors decrease with the number of ALs. Using the maximum number of easily palpable ALs (13 for pelvis and 4 for femur), average errors were 5.4 and 4.8 mm respectively for pelvis and femur. Better prediction was obtained when the shapes of pelvis and femur were predicted separately without merging the data of both bones. Results also show that the PCA based method is a good alternative to predict hip and lumbosacral joint centers with an average error of 5.0 and 9.2 mm respectively.

Ultrasound-Guided Hip Injections.

The diagnosis of hip pain can be difficult to isolate because the discomfort can originate from several locations and compensatory pain patterns. Pain generators can include the intra- and extra-articular hip structures, the lumbar spine, the pelvic floor, or a combination of these. It can also be referred as pain from the bowel, bladder, or reproductive organs. Injections into and around the hip have become an important part of both diagnostic and nonsurgical treatment algorithm for hip pain. The proximity of the hip to important neurovascular structures, lack of palpable anatomic landmarks, and deep location of targets can make use of ultrasonography-guided injections ideal. These injections have been growing in popularity in the orthopedic community because ultrasonography allows for a real-time visualization of dynamic anatomy without any radiation exposure to the patient and physician. The use of ultrasonography has allowed for in-office image guidance with improved accuracy for more targeted and advanced procedures. The patient's response to these injections can help guide patient selection for surgery and allow for better pain control of the soft-tissue pathology that often accompanies intra-articular pathology. This article highlights the diagnostic and therapeutic value of ultrasonography-guided hip injections for an orthopedic practice. The focus is on sonographic anatomy, introduction to technique, common indications, and pearls and pitfalls of these procedures.

A 3-Dimensional-Printed Spine Localizer: Introducing the Concept of Online Dissemination of Novel Surgical Instruments.

Background/AimsTo date, applications of 3-dimensional (3D) printing in neurosurgery have been limited to the creation of anatomical models for training and simulation, fabrication of customized implants, and production of patient-specific surgical tool guides. We aim to demonstrate a new application of this technology for the online dissemination of novel surgical instrument designs across the world. MethodsA link to a 3D printing file and instructions for assembly of a spine localizer are included in this article. This device was used to determine the optimal location of skin incision in lumbar microsurgery in 43 consecutive patients. Data regarding the accuracy of the surgeon's initial estimate of the target site based on palpation of anatomical landmarks and the accuracy of the localizer device in locating the target spine segment were prospectively collected. ResultsIn 35 cases (81%), the surgeon’s initial estimate of the target site was correct. In the remaining 8 cases (19%), the initial estimate was off by 1 motion segment. Inaccuracy of the surgeon’s estimate was found to be associated with a higher body mass index and the presence of transitional lumbosacral anatomy, but not with age, sex, or location of the target segment. In all patients, the location of the incision guided by the localizer was found to overlie the target segment, yielding a device accuracy of 100%. There was no need to extend the incision or modify the surgical trajectory. ConclusionThis 3D-printable localizer serves as an example of a device that can be disseminated online and printed at the point of use, thus promoting online tool-sharing by neurosurgeons.

CAUDAL ANESTHESIA DURING BRACHYTHERAPY FOR PROSTATE CANCER (CASE REPORT)

The case report of anesthesia during brachytherapy for prostate cancer in patient with spinal comorbidity and neurological deficits has been presented. It has been shown that caudal anesthesia with MR-scanning, palpation of anatomical landmarks and ultrasonography navigation might be a method of choice in this patients.

Description of a regional anaesthesia technique for the dorsal cranium in the dog: a cadaveric study

ObjectiveTo identify landmarks and to describe a technique for nerve blockade of the dorsal cranium in dogs. Study designAnatomic cadaveric study. AnimalsA total of 39 dog cadavers, weighing 18.0 ± 9.7 kg (mean ± standard deviation). MethodsThe study was performed in three parts. In the initial part, cadavers were dissected to determine the location of the frontal, zygomaticotemporal, and major occipital nerves, and to identify prominent landmarks for their blockade. In the second part, one technique was developed to block each of the frontal and zygomaticotemporal nerves, and two techniques, rostral and caudal, were developed to block the major occipital nerve. Injection solution was 0.05% methylene blue in 0.5% bupivacaine. In the third part, cadavers were used to test the techniques developed in the second part with 0.04 mL kg−1 of the same injectate administered at each site (maximal volume 0.5 mL per site). The length of nerve stained was measured, with a length ≥6 mm considered successful. Confidence intervals were calculated using Fisher’s exact test. ResultsSuccess rates (95% confidence interval) for the frontal, zygomaticotemporal, and rostral and caudal locations for the major occipital nerve were 94% (80–99%), 91% (76–98%), 74% (58–86%) and 77% (59–89%), respectively. With a combination of both locations, the success rate for the major occipital nerve was 100% (90–100%). Conclusion and clinical relevanceThis study describes a simple regional anaesthesia technique using palpable anatomical landmarks that may provide analgesia for dogs undergoing craniotomy.

The Free-Hand Technique for S2-Alar-Iliac Screw Placement: A Safe and Effective Method for Sacropelvic Fixation in Adult Spinal Deformity.

Spinopelvic fixation is an integral part of achieving solid fusion across the lumbosacral junction, especially in deformity procedures requiring substantial correction or long-segment constructs. Traditional S2-alar-iliac (S2AI) screw-placement techniques utilize fluoroscopy, increasing operative time and radiation exposure to the patient and surgeon. We describe a novel free-hand technique for S2AI screw placement in patients with adult spinal deformity. We reviewed the records of 45 consecutive patients who underwent spinopelvic fixation performed with use of S2AI screws by the senior surgeon and various fellows or residents over a 12-month period (2015 to 2016). In each case, the S2AI screws were placed utilizing a free-hand technique without fluoroscopic or image guidance. Screw position and accuracy were assessed by intraoperative O-arm imaging and analyzed using 3-dimensional interactive manipulation of computed tomography images. A total of 100 screws were placed, 51 by the senior surgeon and 49 by trainees. The mean patient age was 57.4 ± 12.7 years at the time of surgery; 37 (82.2%) of the patients were female. Preoperative diagnoses included adult idiopathic scoliosis (n = 19), adult degenerative scoliosis (n = 15), flatback syndrome (n = 2), fixed sagittal imbalance (n = 6), and distal junctional kyphosis (n = 3). Five (5%) of the screws were placed with moderate to severe cortical breaches, all of which perforated the pelvis posteriorly, with no clinically notable neurovascular or visceral complications. The breach rate did not differ significantly between the senior surgeon and trainees. The free-hand technique for S2AI screw placement, when performed in a standardized manner, was demonstrated to be safe and reliable in constructs requiring spinopelvic fixation. The accuracy of screw placement relies on visible and palpable anatomic landmarks that obviate the need for intraoperative fluoroscopy or image guidance, potentially reducing operative time and radiation exposure. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Reliability and Accuracy of Palpable Anterior Neck Landmarks for the Identification of Cervical Spinal Levels.

Study DesignA descriptive experimental study.PurposeThe purpose of this study was to describe the reliability and accuracy of palpable anterior neck landmarks (angle of the mandible, hyoid bone, thyroid cartilage, and cricoid cartilage) for the identification of cervical spinal levels in a slight neck-extended position as in anterior approach cervical spinal surgery.Overview of LiteratureStandard, palpable anatomical landmarks for the identification of cervical spinal levels were described by Hoppenfeld using the midline palpable anterior structures (angle of the mandible [C2 body], hyoid bone [C3 body], thyroid cartilage [C4–C5 disc], cricoid cartilage [C6 body], and carotid tubercle [C6 body]) to determine the approximate level for skin incisions. However, in clinical practice, patients are positioned with a slight neck extension to achieve cervical lordosis. This positioning (neck extension) may result in changes in the locations of anatomical landmarks compared with those reported in previous studies.MethodsThis experimental study was conducted on 96 volunteers. Each volunteer was palpated for locating four anatomical landmarks three times by three different orthopedic surgeons. We collected data from the level of the vertebral body or the vertebral disc matching the surface anatomical landmarks from the vertical reference line.ResultsAccuracy of the angle of the mandible located at the C2 vertebral body was 95.5%, the hyoid bone located at the C2/3 intervertebral disc was 51.7%, the thyroid cartilage located at the C4 vertebral body was 42%, and the cricoid cartilage located at the C5/6 intervertebral disc was 43.4%.ConclusionsWith the neck in a slightly extended position to achieve cervical lordosis, the angle of the mandible, the hyoid bone, the thyroid cartilage, and the cricoid cartilage were most often located at the C2 body, the C2/3 disc, the C4 body, and the C5/6 disc, respectively. The angle of the mandible and the hyoid bone are highly reliable surface anatomical landmarks for the identification of cervical spinal levels than the thyroid cartilage and the cricoid cartilage.

Factors predictive of topographical accuracy in spine level localization.

Pre-operative spine level localization by palpation of anatomical landmarks (ribs, spinous processes) in posterior approaches for surgeries from T4 to L2 is often inaccurate. This can lead to ineffective utilization of procedural time, increased radiation dose, potentially longer skin incision and wrong level surgery. Factors affecting topographical accuracy includes body mass index (BMI) of the patient, congenital or acquired deformity and knowledge of topographical anatomy. All patients had the presumed location of their pathology marked on the skin using anatomical landmarks prior to application of the Target Tape® (Vancouver, BC, Canada) and verification using an anterior-posterior radiograph. Potential factors predictive of accurate pre-operative spine level localization such as age, gender, BMI, palpable deformity, pathology related interspinous distance (ISPD) and pathology related skin to spinous process distance were evaluated. A prospective study was performed with 30 consecutive patients undergoing posterior spine surgery (T4 to L2). Accuracy of pathology related spine level localization using anatomical landmarks was only 40%. Pathology related ISPDs of more than 10 mm and palpable deformity was significantly correlated with successful determination of spine levels using anatomical landmarks. This study showed that poor spine level localization using anatomical landmarks was associated with pathology related ISPDs of less than 10 mm. Conversely, patients with palpable spinal deformity have their levels easily localized.

Does Preprocedural Ultrasound Increase the First-Pass Success Rate of Epidural Catheterization Before Cesarean Delivery? A Randomized Controlled Trial.

Preprocedural ultrasound may improve the efficacy and safety of epidural catheterization, especially in difficult cases. Most studies of ultrasound-assisted epidural catheterization in the obstetric population are dated and nonblinded with inconsistent designs. This double-blind, randomized controlled study aimed to compare the ultrasound-assisted with the conventional palpation techniques for epidural catheterization in parturients undergoing cesarean delivery. We hypothesized that the use of preprocedural ultrasound would increase the success rate of epidural catheterization at the first needle pass. Eligible subjects were American Society of Anesthesiologists physical status II parturients with full-term singleton pregnancy undergoing elective cesarean delivery using double-interspace combined spinal-epidural anesthesia. Exclusion criteria were age <19 or >40 years, body mass index ≥35 kg/m, women presenting in labor or having any contraindication to neuraxial anesthesia, marked spinal deformity, previous spinal surgery, or impalpable anatomical landmarks. One hundred ten patients were randomly allocated into 2 equal groups (palpation and ultrasound groups). All procedures were performed by a single experienced anesthesiologist. Patients and investigators assessing the outcome data were blinded to group allocation. A systematic spinal ultrasound assessment and a sham procedure were performed in the ultrasound and palpation groups, respectively, before attempting epidural catheterization. The primary outcome was the rate of successful epidural catheterization at the first needle pass. Secondary outcomes were the rate of successful epidural catheterization at the first skin puncture, number of performed needle passes and skin punctures, duration of the epidural procedure, patient satisfaction from the procedure, and complications of the procedure (incidence of unintentional dural and vascular punctures, failed block, unilateral or patchy block, and backache). Data from 108 patients (55 patients in the palpation group and 53 patients in the ultrasound group) were analyzed. The rate of successful epidural catheterization at the first needle pass was 60% in the palpation group and 58.5% in the ultrasound group (95% confidence interval of the difference in proportions between groups is -18.5% to 21.6%; P > 0.99). There were no significant differences between the 2 groups in the success rate at the first skin puncture, the number of needle passes and skin punctures, or patient satisfaction. The median (range) duration of the epidural procedure was 185 (57-680) seconds in the ultrasound group and 215 (114-720) seconds in the palpation group (P = 0.036 with the Mann-Whitney U test and P = 0.083 with the Student t test with unequal variances). The overall rate of complications of the procedure was low in both groups. For experienced anesthesiologists, it remains unclear whether preprocedural ultrasound improves the epidural catheterization technique in parturients with palpable anatomical landmarks undergoing cesarean delivery.

Prediction of the drilling path to surgically pin the femoral neck from the spatial location of pelvic and femoral anatomical landmarks: A cadaver validation study

Several clinical applications rely on accurate guiding information when drilling along the femoral neck (e.g., pin insertion in case of neck fracture). Currently, applications rely on real-time X-ray imaging, which results in irradiation issues for the surgeon conducting the operation. The goal of this paper was to develop an X-ray-free method that would allow for a pathway to be drilled between the lateral aspect of the femoral diaphysis (the so-called piercing point), the femoral neck and the head centres. The method is based on on-the-fly computational predictions relying on a biomechanical database that includes morphological data related to the femoral neck and head and various palpable anatomical landmarks located on the pelvis and the femoral bone. From the spatial location of the anatomical landmarks, scalable multiple regressions allow for the prediction of the most optimal drilling pathway. The method has been entirely validated using in vitro experiments that reproduce surgical conditions. Further, a surgical ancillary prototype that integrates the method of guiding the pin drilling has been developed and used during in vitro and in situ validation using nine hip joints. Pin insertion was controlled after drilling using medical imaging and show successful result for each of the nine trials. The mean accuracy of the estimated hip joint centre and neck orientation was 6.0 ± 2.8mm and 7.1 ± 3.8°, respectively.

The safe zone for blinded sternal interventions based on CT evaluation of midline congenital sternal foramina

The aim of this study was to evaluate the safe zone for performing blind sternal procedures based on computed tomography (CT) evaluation of congenital midline sternal foramina using multidetector computed tomography (MDCT). This retrospective study was carried out on 1,180 patients who underwent MDCT of the thorax from March 2015 to February 2016. The MDCT images were evaluated in axial and reformatted planes. Morphometry and prevalence of midline congenital sternal foramina (SF) and manubrio-foraminal distance (MFD) were evaluated. The safe zone was defined for a blinded intervention, based on palpable anatomical landmarks. Data were presented in terms of percentage, mean±standard deviation and calculations were carried out using Microsoft Excel. The prevalence of SF in our study sample was 11.6%. The majority of SF were located in a typical position in the lower sternal body at the level of fifth costo-chondral junction (CCJ) in 108 patients (78.8%). The structure directly beneath the SF was mediastinal fat in 73 patients (53.3%), followed by anterior pericardium in 44 patients (32.1%) and lung parenchyma in 20 patients (14.6%). The mean MFD in our study population was 11.90 ± 1.31cm. Sternal interventions should be avoided at the level of fourth to sixth CCJ, which is considered the danger zone. An intervention at the fourth to sixth CCJ may lead to disastrous consequences in patients who have SF.

Comparison of the landmark and ultrasound methods in cesarean sections performed under spinal anesthesia on obese pregnants

Difficulties in the palpation of anatomical landmarks in pregnancy due to obesity may create problems in the regional anaesthesia. Objective of this study was to compare ultrasound examination carried out before the procedure with conventional spinal anaesthesia method with papation of bony landmarks in caesarean sections performed under spinal anaesthesia in obese pregnants. Ninety-seven obese pregnants having pre- and post-pregnancy body mass index > 30 kg/m2 were prospectively examined. Patients were randomised to two groups as landmark group (n = 49) and ultrasound group (n = 48). The needle insertion point was determined at L4–L5 level before the procedure through palpation in the landmark group and with the examination in the ultrasound. The numbers of skin punctures and needle passes, total procedure time (TPT) and spinal block occurrence time (SBOT) were recorded. TPT was significantly longer in the ultrasound than in the landmark group (p < 0.001) (8 ± 2 and 5 ± 1; respectively). Whereas SBOT values were similar (p = 0.063). The numbers of skin punctures and needle passes were significantly fewer in the ultrasound than in the landmark group (p < 0.001). We believe that, accurate determination of the needle introducing site before the procedure by viewing the vertebral structures through ultrasound examination in obese pregnants could increase the success rate.