Computational Imaging-Processing Comparison for Lumbar Spine Cadaveric Specimens with Clinical Medical Physics Applications

A series of improved imaging-computational and algorithmic methods for new/different lumbar cadaveric specimens was obtained. These are based on previous publications [3,3.1], with an improved-imaging research line. Results show a systematic study of each lumbar cadaveric specimen. Enhanced imaging findings and resolution for vertebral facets/positioning, contrast, anatomical parts separation and visualization of lumbar spines are demonstrated. Medical Physics and clinical bioengineering advances related to previous contributions are proven with imaging processing, programming codes/patterns, and computer vision tools. Findings constitute computational imaging methods which are appropriate for sharp and detailed anatomical-clinical analysis and comparisons among cadaveric specimens. These processing solutions are useful for lumbar spine computational study and anatomical dissection. Applications on Medical Physics, Biomedical Engineering, and Computational-Forensic Diagnosis are obtained from this cadaveric imaging systematic comparison and software methods.

Biomechanical Comparison of a Prepared Thick Fresh Frozen Irradiated Fascia Lata Allograft to the Native Superior Capsule (212)

Objectives: Superior Capsule Reconstruction (SCR) has been described as treatment option for irreparable tears of the superior rotator cuff. Reported outcomes on the success of the surgery have been variable, with graft choice seeming to be one of the most important factors. Fascia Lata (FL) allograft has been proposed as a potential option as it provides adequate graft thickness while avoiding the morbidity of an autograft harvest. The purpose of this study was to compare the biomechanical characteristics of an SCR with FL allograft (FL-SCR) to a native superior capsule in a cadaveric specimen. Methods: Eight cadaver shoulder specimens were used. Each specimen was tested with a custom shoulder system twice. Initial testing was performed after the specimen was dissected of all soft tissue except for the native superior capsule. Subsequent testing was performed after FL-SCR was done. All allografts were fresh frozen and irradiated. Capsule and graft dimensions were recorded before testing. Biomechanical values recorded were cyclic and load to failure for both the native capsule and FL-SCR, and fixation displacement for the SCR-FL construct. A Paired T-test was performed to compare the biomechanical values of the native superior capsule to the FL-SCR. Results: The mean thickness of the NSC was 2.4 ± 0.6 mm and 7.4 ± 1.2mm for the FL graft. The native superior capsule had an average linear stiffness of 94.5 ± 20.4 N/mm, yield load of 386.9 ± 63.6 N, ultimate load of 444.9 ± 67.7 N and energy absorbed of 1418.4 ± 248.8 N-mm. The FL-SCR construct had an average linear stiffness of 28.0 ± 1.6 N/mm, yield load of 123.8 ± 54.3 N, ultimate load of 369.0 ± 43.4 N and energy absorbed of 5021.2 ± 755.1 N-mm. Comparing the two groups there was a statistically significant difference for stiffness (P = 0.013), yield load (P = 0.03) and energy absorbed (P = 0.003). There was no statistically significant difference between ultimate load. The total displacement of the FL-SCR fixation was 5.8 ± 0.6 mm after 1 cycle, 8.5 ± 0.7 mm after 30 cycles, 11.4 ± 1.8 mm at the yield load and 29.5 ± 1.8 mm at the ultimate load. For the failure mode, 8/8 NSC specimens failed at the mid-substance. The FL-SCR, 3/8 specimens failed at the suture tendon interface and 4/8 had medial anchor pull out. Conclusions: Performing SCR with FL allograft in a cadaver model creates a construct that is sufficiently strong enough to withstand normal physiologic loading of the shoulder, although it does not fully re-create the biomechanical characteristics of a native shoulder superior capsule.

Improving mandibular reconstruction by using topology optimization, patient specific design and additive manufacturing?—A biomechanical comparison against miniplates on human specimen

In this study, topology optimized, patient specific osteosynthesis plates (TOPOS-implants) are evaluated for the mandibular reconstruction using fibula segments. These shape optimized implants are compared to a standard treatment with miniplates (thickness: 1.0 mm, titanium grade 4) in biomechanical testing using human cadaveric specimen. Mandible and fibula of 21 body donors were used. Geometrical models were created based on automated segmentation of CT-scans of all specimens. All reconstructions, including cutting guides for osteotomy as well as TOPOS-implants, were planned using a custom-made software tool. The TOPOS-implants were produced by electron beam melting (thickness: 1.0 mm, titanium grade 5). The fibula-reconstructed mandibles were tested in static and dynamic testing in a multi-axial test system, which can adapt to the donor anatomy and apply side-specific loads. Static testing was used to confirm mechanical similarity between the reconstruction groups. Force-controlled dynamic testing was performed with a sinusoidal loading between 60 and 240 N (reconstructed side: 30% reduction to consider resected muscles) at 5 Hz for up to 5 · 105 cycles. There was a significant difference between the groups for dynamic testing: All TOPOS-implants stayed intact during all cycles, while miniplate failure occurred after 26.4% of the planned loading (1.32 · 105 ± 1.46 · 105 cycles). Bone fracture occurred in both groups (miniplates: n = 3, TOPOS-implants: n = 2). A correlation between bone failure and cortical bone thickness in mandible angle as well as the number of bicortical screws used was demonstrated. For both groups no screw failure was detected. In conclusion, the topology optimized, patient specific implants showed superior fatigue properties compared to miniplates in mandibular reconstruction. Additionally, the patient specific shape comes with intrinsic guiding properties to support the reconstruction process during surgery. This demonstrates that the combination of additive manufacturing and topology optimization can be beneficial for future maxillofacial surgery.

Cadaveric study investigating the phrenic-sparing volume for anterior suprascapular nerve block

BackgroundThis cadaveric study investigated the maximum effective volume of dye in 90% of cases (MEV90), required to stain the suprascapular nerve while sparing the phrenic nerve during the performance of an anterior suprascapular nerve block.MethodsIn cadaveric neck specimens, using ultrasound guidance, the block needle was advanced until its tip was positioned underneath the omohyoid muscle next to the suprascapular nerve. The dye was injected in order to achieve circumferential spread around the latter. Successful phrenic-sparing suprascapular nerve block was defined as the non-staining of the phrenic nerve on dissection. Volume assignment was carried out using a Biased Coin Design, whereby the volume of dye administered to each cadaveric specimen depended on the response of the previous one. In case of failure (ie, stained phrenic nerve), the next one received a lower volume (defined as the previous volume with a decrement of 2 mL). If the previous cadaveric specimen had a successful block (ie, non-stained phrenic nerve), the next one was randomized to a higher volume (defined as the previous volume with an increment of 2 mL), with a probability of b=0.11, or the same volume, with a probability of 1 – b=0.89.ResultsThirty-one cadavers (56 cadaveric neck specimens) were included in the study. Using isotonic regression and bootstrap CI, the MEV90 for phrenic-sparing anterior suprascapular nerve block was estimated to be 4.2 mL (95% CI 3.0 to 5.0 mL). The probability of a successful response was estimated to be 0.90 (95% CI 0.84 to 0.96).ConclusionFor ultrasound-guided anterior suprascapular nerve block, the MEV90 of dye required to spare the phrenic nerve is 4.2 mL. Further studies are required to correlate this finding with the MEV90 of local anesthetic in live subjects.

Anatomical characteristics of the accessory hepatic lobe and its clinical-functional particularities

Riedel's lobe (ectopic lobe), also known as the accessory hepatic lobe, consists of an anatomical variation characterized by a tongue-shaped protrusion on the visceral surface of the liver right lobe, fixed by a pedicle. This variant draws attention in the clinical practice, as it can be mistaken for a tumor due to its elongated aspect. The aim of this research was to conduct a study on the anatomical characteristics and clinical and functional peculiarities of the accessory hepatic lobe. The paper is based on a integrative review and observational study on a cadaveric specimen. A cadaver with anatomical variation was used. Data were collected in PubMed, Scielo, and VHL. 257 articles were found in the databases, but only 13 were used for research. In careful review, two rare cases of the accessory lobe in the left lobe of the liver, hypoplastic left lobes, and agenesis of the right hepatic lobe, and often the clinical picture without changes in signs and symptoms were found. These morphological abnormalities' clinical impact is limited in the absence of underlying liver disease, cirrhosis, or known cancer. In case of complications or after the diagnosis of pedunculated tumors in the liver, laparoscopy is well indicated for removing these lobes or tumors.

Cadaveric investigation of the minimum effective volume for ultrasound-guided suprainguinal fascia iliaca block

BackgroundThis cadaveric dose-finding study investigated the minimum effective volume of dye in 90% of cases (MEV90), required to stain the femoral, lateral femoral cutaneous and obturator nerves for ultrasound-guided suprainguinal fascia iliaca block (SIFIB).MethodsIn cadaveric specimens of the lower limb, the block needle was advanced, medial to the anterosuperior iliac spine, until its tip was positioned between the internal oblique and iliacus muscles underneath the fascia iliaca. The dye was injected inside the fascia iliaca compartment. Volume assignment was carried out using a biased coin design, whereby the volume of dye administered to each cadaveric specimen depended on the response of the previous one. In case of failure, the next one received a higher volume (defined as the previous volume with an increment of 2.5 mL). If the previous cadaveric specimen had a successful block, the next one was randomized to a lower volume (defined as the previous volume with a decrement of 2.5 mL), with a probability of b=0.11, or the same volume, with a probability of 1–b=0.89. Success was defined as the staining of the femoral, lateral femoral cutaneous, and obturator nerves on dissection.ResultsThirty-six cadavers (60 cadaveric specimens) were included in the study. Using isotonic regression and bootstrap CI, the MEV90 for ultrasound-guided SIFIB was estimated to be 62.5 mL (95% CI 60 to 65).ConclusionFor ultrasound-guided SIFIB, the MEV90 of dye required to stain the femoral, lateral femoral cutaneous and obturator nerves is 62.5 mL. Further studies are required to correlate this finding with the MEV90 of local anesthetic in human subjects.

High Brachial Artery Bifurcation Clinical finding in Cadaveric Specimen by Medical Students During Internship

The high brachial artery bifurcation is an anatomical variation found in the arm segment. Although it does not present any alteration in the arterial blood functionality, it is considered a common spot for vascular lesions during surgical interventions that consist of the absence of anatomical knowledge. The research objective was to describe the high brachial artery bifurcation found in a cadaveric specimen from the anatomy laboratory as well as its main anatomoclinical aspects. Twenty-six upper limbs were investigated and dissected from the Universidade Brasil's Human Anatomy Laboratory, SP. These were formolized cadaveric specimens from both sexes. During upper limb dissection, arterial anatomical variations were observed in a single-arm segment. The variation was unilateral in the left hemisphere. The clinical findings were high brachial artery bifurcation and a rare case of the radial artery in the medial path, as well as an ulnar artery with a lateral path in the arm median third. It is clear that the understanding of anatomy and anatomical variations patterns is of utmost importance and a requirement for surgery, so surgeons need to be aware of clinical, anatomical, and arterial variations data, avoiding vascular lesions during the surgical interventions. Dissection is an important learning tool for students and resident doctors. It is suggested the use of dissection as a pedagogical resource to acquire skills in surgeries during internship and also to improve the anatomical variation cognition of upper limbs.

Anatomical Variation in Extrahepatic Biliary Apparatus

Background: For several years, the pathology of the biliary system has been the focus of prolonged study. Largely due to their surgical relevance and the simplicity with which they can be treated in cholecystectomies. While interest in extrahepatic bile ducts has been intensified, very rare studies have been performed on the Indian subcontinent. The anatomical differences of the extra-hepatic biliary area were defined in this study, as these variations are important throughout surgical techniques such as laparoscopic cholecystectomy, thus minimising post-operative difficulties. The objective is aim of the research was to observe anatomical differences in the extrahepatic biliary system in Indian cadaveric specimen samples. Subjects and Methods : Sample content consisted of 100 human cadavers of any sex that were dissected. Cadaver specimens from the dissection room were examined. Cadaver specimens were obtained from Mata Gujri Memorial Medical College, Kishanganj, Bihar, Department of Anatomy. By the traditional method of dissection, they were studied. Results: In the current study, the smallest gall bladder observed was around 25ml, while the largest gall bladder was around 120ml. On average, our study recorded around 50 ml of the gall bladder. Congenital anomalies of the gall bladder included Intrahepatic, Double, Bilobed and separate mesentery. Further, the pathological findings accounted for 20% of total cases and a solitary pathology involving carcinoma was noted. Conclusion: Anatomical variants of the extrahepatic biliary system are widespread and are important for surgeons to prevent injury as critical structures through surgical operations and increase surgical results by recognising them.