Thiel-embalmed Cadavers Research Articles

Surgical training in extraperitoneal laparoscopic para‑aortic lymphadenectomy for the treatment of gynecological cancer using a Thiel‑embalmed cadaver.

The extraperitoneal laparoscopic approach (ELPAN) for para-aortic lymphadenectomy provides excellent visibility of the left side of the aorta, thus facilitating surgery in the retroperitoneal space. This technique is highly complex compared with the transperitoneal approach. In particular, advanced techniques are required to develop an appropriate surgical field in the narrow retroperitoneal space; therefore, surgeons need to undergo a significant amount of training to become competent. A variety of tools are available for surgical training but are limited by their ability to reproduce complex anatomy. Thus, cadavers may represent the most suitable tool for learning this unique technique. The present study describes a surgical training protocol for the ELPAN technique using a Thiel-embalmed human cadaver and provides a step-by-step description of the ELPAN technique performed at Okayama University (Okayama, Japan). A 72-year-old Thiel-embalmed female cadaver was used to develop a protocol for surgical training in the ELPAN technique that effectively reproduced the methodology required in clinical practice. A training method for ELPAN surgery was developed and successfully completed using the Thiel-embalmed cadaver that secured the surgical field in the retroperitoneal space and permitted resection of the lymph nodes. The Thiel-embalmed cadaver tissue possessed excellent properties for surgical training, including color tone, flexibility, and the membrane structure of connective and fat tissues. In addition, this method of fixation preserved stiffness and elasticity of the peritoneum, although large vessels were slightly fragile and poorly extensible. Surgical training using a Thiel-embalmed human cadaver represents a valuable option for learning the ELPAN surgical technique. However, this technique may be unsuitable for training in perivenous manipulation. To the best of our knowledge, this is the first report to describe the use of Thiel-embalmed cadavers as a tool for surgeons to undergo training in the ELPAN technique.

The morphometric parameters of the biceps brachii: cadaveric study.

The biceps brachii (BB) is a fusiform muscle comprising of two muscular bellies located in the anterior compartment of the arm. Its primary function includes elbow flexion and forearm supination. The study aimed to examine the morphometric parameters of the BB in adult cadaveric specimens. This dissection-based study examined the anatomy of the BB in 40 arms taken from 20 Thiel embalmed European cadavers, including 13 males with an average age of 81 years and seven females with an average age of 84 years. The investigation included an observational inspection of the BB morphology and collected 19 parameters, comprising the lengths and widths of the short and long head tendons and muscle bellies. The observation analysis showed that the anatomy of the BB consisted mainly of two muscle bellies: a short head and a long head. An additional third humeral head, originating from the anteromedial aspect of the mid of the humerus and inserted into the common biceps tendon, was observed in four (10%) specimens. The average lengths of the short head and long head were 35.98 ± 3.44cm and 38.90 ± 3.40cm, respectively. There was no difference in the BB parameters according to the arm sides. However, the male specimens showed greater BB parameters than the female specimens. The short head had a greater muscle belly, while the long head had a longer origin and insertion tendons. The BB parameters were correlated positively with the humerus length.

Colorimetric variations in cadaveric tissues embalmed with modified Thiel\\\'s and Formalin solutions: An objective comparative study using image J

The comparison of tissue colour between Thiel's embalmed cadavers (TEC) and formalin-embalmed cadavers (FEC) is crucial for assessing the efficacy of Thiel embalming technique as a suitable alternative to formalin embalming for surgical skill training and anatomical education. Most of the studies which declare the superiority of tissue colour in TEC over FEC have done subjective assessment and comparison of the tissue colour. This study aims to compare the colour difference between Thiel and formalin embalmed cadavers objectively. : The current study used six human cadavers to compare the effects of two embalming methods, Modified Thiel’s solution (MTS) and Modified Formalin Solution(MFS). The tissues of the cadavers were dissected and photographed to be analysed for Red, Blue, Green values using Image J software. The mean (SD) R-value (Red), G-value (Green), and B-value (Blue) for MTS embalmed cadavers were 149.78 (16.070), 124 (19.675), and 109.96 (9.852), respectively, from pictures of embalmed cadavers from research groups. The mean RGB value of MTS embalmed cadavers was substantially (P<0.05) higher than MFS embalmed cadavers. The current research found that MTS-embalmed cadavers have greater RGB values than MFS-embalmed ones. This information helps to fully understand tissue property changes, evaluate their impact on student perceptions and learning outcomes, and determine Thiel embalming's suitability for surgical training and workshops.

The spread of injectate after deep serratus anterior plane and superficial parasternal intercostal plane blocks: a cadaveric dye study.

We investigated the distribution of injected dye after deep serratus anterior plane and superficial parasternal intercostal plane blocks in 15 Thiel embalmed cadavers. We injected 0.4 ml.kg-1 of 0.25% aqueous methylene blue solution into the deep serratus anterior and superficial parasternal intercostal planes using real-time ultrasound needle visualisation followed by posterior dissection to observe the distribution of the injected dye in the chest wall. The two blocks were performed bilaterally in 15 cadavers at the T5/T6 level, comprising 60 blocks in 30 hemithoraces in total. At dissection, the intercostal nerve territories were observed to be dyed completely from T2 to T6 in 28 of 30 hemithoraces, and extending caudal to T6 in 10 hemithoraces. Following the deep serratus anterior plane blocks in all cadavers, the dye was found to have spread to the axillae. Following the superficial parasternal intercostal plane blocks, the dye reached T7 in four cadaver dissections. We concluded that the territories innervated by the intercostal nerves (T2-T6 dermatomes) are dyed following the combination of the two blocks when performed at the T5-T6 intercostal space level. These techniques might provide an effective option for anaesthesia in breast surgery.

Evaluation of Modified Thiel Soft-embalmed Cadavers as a Novel Teaching Model for Musculoskeletal Ultrasound and Anatomy among Rehabilitation Medicine Residents.

This study aimed to determine the perceptions of rehabilitation medicine resident trainees on using modified Thiel soft-embalmed cadavers as a learning tool in acquiring knowledge on musculoskeletal ultrasound (MSK-UTZ) and anatomy. This descriptive cross-sectional study used total enumeration to recruit residents in training under the rehabilitation medicine department of a tertiary referral hospital. An online survey tool was self-administered to determine their perceptions on the use of MSK-UTZ on Thiel-embalmed cadavers. Pre- and post-test scores were compared to determine if their knowledge has improved. Fifteen participants were recruited, who answered the pre- and post-test, and the online survey. The mean pre-test score of participants was 5.87 (±1.68), and the mean post-test score was 6.87 (±2.00). There was no statistically significant difference (P = 0.20) using a paired t-test. At an arbitrary passing rate of 70%, only 5/15 participants passed the pre-test while 10/15 passed the post-test. A chi-square test of independence showed that there was no significant association between the number of participants who passed or failed on the pre- and post-test, X2 (1, N = 15) = 3.3, p = .0.068. Most of the perceptions of the participants were positive in terms of the use of modified Thiel soft-embalmed cadavers as a learning tool, its relevance in the training of a rehabilitation medicine resident, and the overall experience on its use. Thiel-embalmed cadavers as a learning tool was well-accepted, having generally positive perceptions from the participants mainly in terms of perceived enhancement of the understanding of the anatomical basis of musculoskeletal ultrasound, perceived improvement in skills in performing musculoskeletal ultrasound, and most even recommended that it be part of their training as rehabilitation medicine residents. In terms of acquiring knowledge on musculoskeletal ultrasound (MSK-UTZ) and anatomy, no significant improvement in knowledge was noted. Further studies with larger sample sizes are recommended to yield more statistically significant improvement in knowledge and to observe trends in the perceptions of participants.

A technique for decreasing reflection during cadaveric photography.

To create anatomical educational materials that can be viewed in three dimensions using stereo photographs and photogrammetry, multiple photographs must be taken from different directions. In this process, shadows and reflections from different positions in each photograph are undesirable for creating three-dimensional (3D) anatomy educational materials. Although a ring flash eliminates shadows, allowing light to enter from all directions, reflections cannot be eliminated. In particular, Thiel-embalmed cadavers, which are widely used in clinical anatomy, are highly wet and exhibit strong specular highlights. In this study, a straight polarization filter was attached to a handheld camera lens and ring flash, and shooting was performed using cross-polarization photography. Consequently, even in Thiel-embalmed cadavers, the details lost due to the effects of reflections and shadows can be recovered, and good results can be obtained when taking stereo photos or creating a 3D model using photogrammetry.

Relationship between shear elastic modulus and passive muscle force in human hamstring muscles using a Thiel soft-embalmed cadaver.

Assessing muscle flexibility and architecture is important for hamstring strain injury (HSI) prevention. We investigated the relationship between shear modulus and passive force in hamstring muscles at different sites and the effect of muscle architecture on the slope of the shear modulus-passive force using shear wave elastography (SWE). The biceps femoris long head (BFlh), semitendinosus (ST), and semimembranosus (SM) muscles were dissected from nine Thiel-embalmed cadavers and fixed to a custom-made mechanical testing machine. Calibrated weights (0-1800g) were applied gradually in 150-g increments. The shear modulus and anatomical cross-sectional area (ACSA) were measured at proximal, central, and distal points using SWE. The muscle mass and length were measured before the loading test. The shear modulus-passive load relationship of each tested muscle region was analyzed by fitting a least-squares regression line. The increase in shear modulus slope per unit load was calculated and compared between the muscles before and after normalization by the muscle mass, length, and ACSA. The shear modulus and passive force for all hamstring muscles in each region showed a statistically significant linear correlation. Furthermore, the increase in shear modulus slope was greater for BFlh and ST than for SM (P < 0.05), but after normalization by the muscle length and ACSA, there were no significant differences among the muscles. The local mechanical properties of individual hamstring muscles can be indirectly estimated using SWE, and the slope of increase in shear modulus reflects characteristics of the muscle architecture.

Use of Thiel-embalmed cadavers in urology training and their ability to retain real-life anatomy: a systematic review.

Thiel-embalmed cadavers (TeCs) have been proposed as an alternative and probably safer method of surgical training, compared to formalin-embalmed cadavers. We aimed to perform a systematic review on the use of TeCs in urology training and their ability to represent real-life anatomy. PubMed, SCOPUS and Cochrane databases were searched for articles with purpose to explore the use of TeCs in urology training, without date restrictions, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. From each paper, we evaluated the type of procedure, the number of participants, the type of study, the educational outcomes and their level, according to Kirkpatrick hierarchy. Of the 225 records initially retrieved, eight articles were eventually included. All studies evaluated participants' perceptions about the procedure. Overall, urology trainees and specialists have positively commented on the educational value of TeCs, which have been also found able to adequately mimic real-life conditions. In all the eight studies, trainees stated that tissue quality of TeCs was adequately realistic and considered TeCs as a useful surgical training tool. Although the use of TeCs in urology training has so far been limited, their value as a surgical training tool has been positively perceived. These outcomes suggest that TeCs may also enhance urology trainees' surgical skills and may encourage their implementation as a simulation tool in urology training.

The suprascapular nerve block (SScNB) is easily administered using a landmark-based technique: A cadaveric study to assess nerve staining post-injection.

The suprascapular nerve is an ideal target for nerve blockade to alleviate shoulder pain given its widespread innervation to the shoulder girdle. To widen availability of this treatment, we investigate whether an anatomical landmark technique can be adopted by novice injectors to provide efficacious blockade. Five injectors were recruited with varying experience. 10 shoulders of Thiel embalmed cadavers were injected with blue dye. Written instructions and an illustration of the Dangoisse landmark technique were provided prior to injection. Cadavers were dissected and the presence or absence of dye staining reported by three observers and a consensus agreement reached. Dissection demonstrated diffuse staining in the suprascapular fossa. 90% of shoulders had adequate staining of the suprascapular nerve directly, or distal branches, which would provide adequate anaesthesia. Inter-observer agreement was good (k = 0.73) for staining at the supraspinous fossa and excellent (k = 0.87) for staining distally. The technique was performed by novice injectors with a good success rate. This technique is reproducible by a range of clinicians to effectively provide anaesthesia of the SScN. Within a resource strained healthcare environment greater uptake of this technique is likely to be of benefit to a wider group of patients.

Quantitative Tissue Elasticity Measurement of Human Cadaver Oesophagus by Using Vibrational Optical Coherence Elastography

The mechanical properties and structure alteration (e.g., layer morphology and thickness) of the oesophagus wall can reflect its pathological conditions. Hence, quantitative measurement of the above-mentioned properties can play a significant role in aiding the disease diagnosis in clinical application. As a fast and non-invasive imaging modality, Optical coherence tomography (OCT) and vibrational elastography can provide high resolution (&lt;10 µm) structural and mechanical mapping of soft tissue. This study is a preliminary study to explore the potential of OCT and VOCE to evaluate both structural and mechanical properties of the oesophagus wall. Jn total, 52 oesophageal tissue samples were acquired from seven human Thiel-embalmed cadavers and were examined by the vibrational OCE. Both the OCT structure image and quantitative elasticity of each sample layer were obtained. In the OCT structure image, the averaged thickness for each sample layer was measured and corresponded with the histological image. Lamina propria has the largest thickness of 158.14 ± 8.75 µm, submucosa is the thinnest with a thickness of 143.19 ± 10.11 µm, and the thickness of muscularis mucosa is 149.49 ± 10.85 µm. Averaged intensity of back-scattered light from each sample layer was evaluated. Intensity of lamina propria layer, muscularis mucosa layer, and submucosa layer have an average value of 79.27 ± 0.51 dB, 69.83 ± 0.56 dB, and 76.10 ± 0.55 dB, respectively. The quantitative elasticity of each sample layer was evaluated in OCE. Elasticity of the lamina propria layer, muscularis mucosa layer, and submucosa layer were estimated as 115.64 ± 8.80 kPa, 60.28 ± 5.27 kPa, and 205.25 ± 19.03 kPa, respectively. The quantitative elasticity results obtained by vibrational OCE corresponded with the collagen distribution trend in each sample layer. This study demonstrates the ability of OCT and vibrational OCE in the characterisation and quantitative evaluation of human cadaver oesophagus wall-structure properties and mechanical properties. The feasibility of applying OCT and vibrational OCE in clinical diagnosis of oesophageal disease is also discussed.

An anatomical approach to the tarsal tunnel syndrome: what can ankle’s medial side anatomy reveal to us?

BackgroundThe heel is a complex anatomical region and is very often the source of pain complaints. The medial heel contains a number of structures, capable of compressing the main nerves of the region and knowing its anatomical topography is mandatory. The purpose of this work is to evaluate if tibial nerve (TN) and its main branches relate to the main anatomical landmarks of the ankle’s medial side and if so, do they have a regular path after emerging from TN.MethodsThe distal part of the legs, ankles and feet of 12 Thiel embalmed cadavers were dissected. The pattern of the branches of the TN was registered and the measurements were performed according to the Dellon–McKinnon malleolar-calcaneal line (DML) and the Heimkes Triangle (HT).ResultsThe TN divided proximal to DML in 87.5%, on top of the DML in 12,5% and distal in none of the feet. The Baxter’s nerve (BN) originated proximally in 50%, on top of the DML in 12,5% and distally in 37.5% of the cases. There was a strong and significant correlation between the length of DML and the distance from the center of the medial malleolus (MM) to the lateral plantar nerve (LPN), medial plantar (MPN) nerve, BN and Medial Calcaneal Nerve (MCN) (ρ: 0.910, 0.866, 0.970 and 0.762 respectively, p < 0.001).ConclusionsIn our sample the TN divides distal to DML in none of the cases. We also report a strong association between ankle size and the distribution of the MPN, LPN, BN and MCN. We hypothesize that location of these branches on the medial side of the ankle could be more predictable if we take into consideration the distance between the MM and the medial process of the calcaneal tuberosity.

Anatomical variation of the sympathetic trunk and aberrant rami communicantes and their clinical implications

Surgical interventions involving the sympathetic trunk are increasingly performed to alleviate symptoms of several disorders such as hyperhidrosis. Anatomical variation has been highlighted as one of the main causes behind surgical failure and symptoms recurrence following surgeries conducted on the chain or its surroundings. This study therefore aimed to record anatomical variants within spinal segments C8-T10 of the sympathetic trunk. Thirty Thiel-embalmed cadavers were investigated bilaterally. The stellate ganglion was recorded on 29 sides. Its size was significantly greater in males and on the right side when the coalescence extended to the subsequent ganglion. The intrathoracic nerve of Kuntz was observed on 21 sides and was significantly more prevalent in males. There was a significant positive association between the presence of this nerve and the descending ramus in the first intercostal space. Aberrant rami found between spinal root C8 and the ventral ramus of the first intercostal nerve were introduced as rami communicantes superi. Aberrant rami communicantes were recorded 50 times in total, of which 70% were found in males. Descending rami showed the highest prevalence in upper intercostal levels, especially in males within the first intercostal space. Aberrant neuronal pathways in upper levels were significantly more prevalent when the stellate ganglion was present. The scientific literature has proven to be stochastic as results were significantly higher in past studies in regard to some sympathetic variants. Anatomical findings of the current study as well as the inconsistency of previous data should be acknowledged and considered for better surgical planning.

A mixed-method evaluation of cadaver surgery training for gynecologic oncology.

Traditional surgical training techniques with using patients, and new advances with live animals, artificial models, and simulation methods have several shortcomings. There are a few reports on the usefulness of cadaver surgery training (CST) in gynecology. Herein, we used a mixed-method evaluation to qualitatively and quantitatively explore the educational efficacy of CST by conducting CST programs at the Sapporo Medical University, Japan. In 2020, we conducted two CST programs with 45 participants-13 residents, 8 specialists recognized by Japan Society of Obstetrics and Gynecology, 23 certified endoscopists recognized by Japan Society of Gynecology and Obstetrics Endoscopy and Minimally Invasive Therapy, 15 specialists recognized by Japan Society of Gynecologic Oncology, and 14 certified endoscopists cum oncology. Three participants observed the procedure virtually and 42 were physically present. Laparoscopic radical hysterectomy and pelvic exenteration were performed on five Thiel-embalmed cadavers. Participants were asked to complete pre- and post-training surveys that included qualitative questions, concerning the purpose and cost of CST, and quantitative questions, testing anatomical knowledge. We observed that the rate of score improvement to the quantitative questions increased from 58.6% pre-CST to 75.6% post-CST. Furthermore, oncology specialists and those who performed more surgeries and faced more complications during surgeries recorded high percentage of correct answers. Multiple regression analysis statistically confirmed these results. This study confirmed the educational efficacy of CST.

"Learning from the experts" - a novel advanced cadaveric course for Gynaecological Oncology (GO) Cytoreductive Surgery.

Ovarian cancer cytoreductive surgery necessitates the use of advanced Simulation-Based Learning (SBL) to optimise skill-based teaching and achieve technical proficiency. We describe and appraise the role of a novel postgraduate cadaveric course for cytoreductive surgery for advanced ovarian/fallopian tube or primary peritoneal cancer. Several consultant-level surgeons with expertise in upper gastrointestinal, colorectal, hepatobiliary and urological surgery, were invited to teach their counterpart gynaecological oncology (GO) surgeons. The 2-day course curriculum involved advanced dissections on thiel-embalmed cadavers. All dissections included applicable steps required during GO cytoreductive surgeries. We used a feedback questionnaire and structured interviews to capture trainers and delegates views respectively. All delegates reported a positive educational experience and improvement of knowledge in all course components. There was no difference in the perception of feedback across junior versus senior consultants. Trainers perceived this opportunity as a "2-way learning" whether they got to explore in depth the GO perspective in how and which of their skills are applicable during cytoreductive surgery. Collaborating with other surgical specialities promotes a "learning from the experts" concept and has potential to meet the rapidly increased demand for multi-viscera surgical excellence in GO surgery. The concept of involving experts from other surgical disciplines in advanced cadaveric courses for cytoreductive surgery in ovarian cancer, will solidify the effort to achieve excellence in the GO training. Such courses can be essential educational adjunct for most GO fellowships.

Internal rotation of the shoulder in the beach chair position may increase the risk of iatrogenic suprascapular nerve injury at the spinoglenoid notch during surgical treatment for shoulder instability.

Suprascapular nerve (SN) at the spinoglenoid notch is a mobile structure which is vulnerable to iatrogenic injury from screw or guidewire penetration during shoulder surgery such as Latarjet procedure or SLAP/Bankart repairs. The primary objective is to identify the distance between posterior glenoid and SN in different shoulder abduction and rotation. The secondary objective is to identify the distance in standard lateral decubitus position. Nineteen shoulders from 10 Thiel embalmed soft cadavers were used in this study. The dissection of posterior shoulder was done to identify the SN at spinoglenoid notch. The distance between the posterior glenoid rim and the SN was measured. In beach chair position, the SN distance from six combinations of shoulder position was obtained: adduction/90° internal rotation (ADIR), adduction/neutral rotation (ADN), adduction/90° external rotation (ADER), 45° abduction/90° internal rotation (ABIR), 45° abduction/neutral rotation (ABN), 45° abduction/90° external rotation (ABER). Subsequently, the suprascapular nerve distance was measured in standard lateral decubitus position with 10lbs. longitudinal traction. In the beach chair position with the shoulder in adduction, the mean distances between the glenoid and the SN in ADIR, ADN and ADER were 15.0 ± 3.3, 19.3 ± 2.6 and 19.5 ± 3.1mm, respectively. During shoulder abduction, the mean distances when the shoulder was in ABIR, ABN and ABER were 15.2 ± 3.4, 19.4 ± 3.0 and 19.3 ± 2.6mm, respectively. The mean distance for the lateral decubitus position was 19.3 ± 2.4mm. The distance between the glenoid and SN was significantly shorter when the shoulder was positioned in internal rotation than in neutral (p < 0.001) or external rotation (p < 0.001) when compared to the same shoulder abduction position. The lateral decubitus position had comparable SN distance with the shoulder position of abduction/neutral rotation in beach chair position. The SN was closest to posterior glenoid rim if the shoulder was in internal rotation. Therefore, shoulder internal rotation must be avoided during guidewire and cannulated screw placement in the Latarjet procedure and drill bit insertion during anchor placement in SLAP/Bankart repair.

Ultrasound-guided single needle tip placement below axillary artery in the infraclavicular area: A cadaveric study.

The parasagittal ultrasound-guided infraclavicular block (ICB) aims to cover all the elements of brachial plexus for the surgeries at and below the elbow. Our aim was to demonstrate the spread of 20 ml latex in vicinity of brachial plexus cords after injecting posterior to the axillary artery in Thiel embalmed cadavers. A blunt insulated needle was inserted posterior to the axillary artery in a traditional parasagittal infraclavicular in 2 Thiel embalmed cadavers, on both the sides (four specimens). A day later cadaver 1 was dissected and cadaver 2 was frozen at ‒20ºC for 2 weeks and sectioned. Both cadavers were photographed. In cadaver 1, dissection revealed a spread of red latex on the lateral cord extending onto the musculocutaneous nerve, the posterior cord engulfing the radial and axillary nerves distally. In cadaver 2, a cross-section revealed latex engulfed all three cords. Single injection of 20 ml latex aimed posterior to the axillary artery in the parasagittal infraclavicular approach engulfed the posterior, medial and lateral cord in Thiel embalmed cadavers. This needs to be investigated in patients who receive ICB clinically and using contrast studies.

Anatomical Topographical Investigation of the Medial Branch of the Dorsal Thoracic Branch of the Spinal Nerve in the Segments T10-T12.

The zygapophyseal joints represent one possible cause for back pain. Therefore, many interventions are targeting the denervation of the facet joints. The aim of this study is to describe the course of the medial branch of the dorsal branch of the spinal nerve and its articular branches to the zygapophyseal joints in the segments T10-T12. The medial branches in the thoracic segments T10-T12 were dissected in 20 Thiel embalmed cadavers. An Eschenbach magnifying glass (4.0× magnification) was used during dissection preserving the articular branches. The topography and the branching pattern of the medial branches was observed. The course of the nerves in the segments T10-T12 differed from each other because of the different osseous anatomy of each segment. The medial branch at the segment T10 crossed the tip of the transverse process in 28 of the 40 hemivertebral specimens. In the remaining cases it passed superior to the transverse process. At T11 the medial branch ran constantly through an osteofibrous canal. At the segment T12 the medial branches showed a similar course to the medial branches in the lumbar region. In many cases two articular branches, which arose from the medial branch were identified. The results of this study show a considerable anatomic variety at the segment T10. It also demonstrates that the transverse process is an important landmark to encounter the medial branch. Furthermore, the possibility of a double innervation of the facet joints should always be considered.

Syndesmotic instability can be assessed by measuring the distance between the tibia and the fibula using an ultrasound without stress: a cadaver study

BackgroundUltrasound examinations for syndesmosis injury might be useful for the quantitative evaluation of syndesmotic instability. The purpose of this study was to evaluate the efficacy of ultrasound assessment by measuring the tibiofibular distance of syndesmosis injuries in various ligament-injured models and stress load conditions.MethodsFive normal ankles from Thiel-embalmed cadavers were used. Ultrasound assessment was performed by placing a probe in parallel with the ligament running just above the anterior inferior tibiofibular ligament (AITFL). The distance between the anterior border of the tibia and the fibula was measured in the intact condition. Next, Bassett’s ligament was cut arthroscopically to reduce damage to soft tissues as much as possible and measurement was performed in the same way. After that, the AITFL, interosseous membrane (IOM), deltoid ligament, and posterior inferior tibiofibular ligament (PITFL) were macroscopically cut and measured in that order. Ankle positions were without stress (natural plantar flexion without applying stress to the ankle joint), dorsiflexion stress, inversion stress, and external rotation stress. All stress to the ankle joint was carried out manually to the maximum extent.ResultsAs with the without-stress condition, significant increases in tibiofibular distances after AITFL dissection were seen compared with the intact state under all stress conditions (intact: 4.9 ± 1.0 mm without stress, 5.6 ± 1.2 mm with dorsiflexion, 5.9 ± 1.0 mm with inversion, and 6.7 ± 1.3 mm with external rotation; AITFL dissection: 6.7 ± 1.5 mm without stress, 7.3 ± 1.2 mm with dorsiflexion, 7.5 ± 1.4 mm with inversion, and 8.7 ± 1.6 mm with external rotation). AITFL dissection with external rotation stress significantly increased the tibiofibular distance compared to without stress.ConclusionChanges in tibiofibular distance with the severity of syndesmosis injury were measured by ultrasound using cadavers. No significant change was seen with Bassett’s ligament injury, but tibiofibular distance increased significantly with injuries of equal to or greater severity than AITFL injury. Results were similar not only for external rotation stress, but also for dorsiflexion stress and inversion stress, and even in unloaded states, significant tibiofibular widening was confirmed with injuries of equal to or greater severity than AITFL injury.

Three-dimensional motion analysis of the hindfoot resulting from simulated contraction of individual lower leg muscles utilizing Thiel-embalmed cadavers

BackgroundJoint movement within the foot is complex involving multiple muscles. We evaluated three-dimensional movement of the hindfoot through simulated traction of extrinsic tendons of the foot. MethodsSix Thiel-embalmed cadavers were utilized and thread was sutured to each tendon of the lower leg muscles. Traction of the thread was prescribed and the change of calcaneal position used to quantify foot motion was measured for each increment using a magnetic tracking system. ResultsAs the tendon traction length advanced, the angle of the calcaneus with respect to the tibia increased linearly. Eversion and abduction angles due to extensor digitorum longus (EDL) traction were significantly greater than that due to the peroneus longus. Plantarflexion due to Achilles tendon traction was significantly greater than that of other plantarflexors. ConclusionsOur results demonstrated three-dimensional characteristics of hindfoot motion by simulated muscle contraction and importance of EDL as an evertor. These information should be applicable for tendon transfer procedures around the ankle and physical therapy for ankle dysfunction such as chronic ankle instability.

Changes in deep neck muscle length from the neutral to forward head posture. A cadaveric study using Thiel cadavers.

Forward head posture (FHP) is one of the most common postural deviations. Deep neck muscle imbalance of individuals with FHP is of primary concern in clinical rehabilitation. However, there is scarce quantitative research on changes in deep neck muscle length with the head moving forward. This study aimed to investigate changes in deep neck muscle length with different severity levels of FHP. Six Thiel‐embalmed cadavers (four males and two females) were dissected, and 16 deep neck muscles in each cadaver were modeled by a MicroScribe 3D Digitizer in the neutral head posture, slight FHP, and severe FHP. The craniovertebral angle was used to evaluate the degrees of FHP. Quantitative length change of the deep neck muscles was analyzed using Rhinoceros 3D. In slight FHP significant changes in length occurred in four muscles: two shortened (upper semispinalis capitis, rectus capitis posterior minor) and two lengthened (longus capitis, splenius cervicis). In severe FHP all occipital extensors were significantly shortened (10.6 ± 6.4%), except for obliquus capitis superior, and all cervical extensors were significantly lengthened (4.8 ± 3.4%), while longus capitis (occipital flexor) and the superior oblique part of the longus colli (cervical flexor) were lengthened by 8.8 ± 3.8% and 4.2 ± 3.1%, respectively. No significant length change was observed for the axial rotator. This study presents an alternate anatomical insight into the clinical rehabilitation of FHP. Six muscles appear to be important in restoring optimal head posture, with improvements in FHP being related to interventions associated with the occipital and cervical extensors.