Orbitocranial Penetration of Ball Bearing Gun Trauma: A Prospective Human Cadaveric Study.

Objective We completed a prospective human cadaveric study to determine the ability of a ball bearing (BB) pellet to penetrate the orbit and/or surrounding structures. Methods A single trained sergeant officer discharged an alloy steel air rifle to eight cadaver orbits from four adult human cadaver heads. Five BB pellets each were aimed at three locations (caruncle, upper eyelid, or lower eyelid) at 10 cm and 1 m, and then less specifically, at the orbital region for 3- and 5-m distances. Computed tomography (CT) of the cadaver heads was performed. Final locations of BB pellets are divided into three categories: intracranial, surrounding orbital structures including the pterygopalatine fossa and infratemporal fossa, and orbit. Results Of 40 BB pellets, 37 penetrated soft tissue and were visualized on CT: 19 (51%) rested in the intracranial space, 17 (46%) in surrounding orbital structures, and 1 (3%) within the orbit. The deepest position of a pellet was in the parietal lobe, and most superficial location anterior to the frontal bone. Pellets discharged from 1 m were more likely to rest in the intracranial space compared with those from 10 cm ( p < 0.001), 3 m ( p = 0.011), and 5 m ( p = 0.004). The distance of discharge was associated with final pellet location ( p = 0.001). Conclusion BB guns should be considered dangerous and potentially deadly when aimed at the orbit. Although the thick calvarium can protect the intracranial space from BB penetration, the orbit may be a vulnerable entry point with relatively low resistance, allowing penetration of the intracranial and periorbital spaces.

Surgical training in extraperitoneal laparoscopic para­aortic lymphadenectomy for the treatment of gynecological cancer using a Thiel­embalmed 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.

An unusual configuration of two anomalies in the extensor digitorum profundus complex in a human.

The extensor digitorum profundus complex underwent degeneration of the ulnar segments during primate adaptation and evolution. This process resulted in the preservation of only the extensor pollicis longus and extensor indicis in some apes, including humans. Consequently, anatomical variations within the digitorum profundus complex in modern humans have been well-documented, with detailed reports on their frequency and patterns in previous studies. Here, we report an unusual arrangement involving two anomalies in the extensor digitorum profundus complex, identified in a 66-year-old Japanese male cadaver. In this cadaver, two accessory muscles differentiated from both the extensor pollicis longus and extensor indicis. Notably, the latter muscle featured a tendon bifurcating towards both the thumb and index fingers, referred to as the extensor pollicis et indicis communis. Under the extensor retinaculum, the tendon of the accessory extensor pollicis longus passed through an independent compartment, whereas that of the extensor pollicis et indicis communis traversed a compartment shared by the extensor indicis and the extensor digitorum communis. Both muscles were innervated by the posterior interosseous nerve. Previous studies have reported that the accessory slip of the extensor pollicis longus and extensor pollicis et indicis communis appear at frequencies of 0.6% and 0.4-1.4%, respectively. However, to the best of our knowledge, a configuration in which both appear simultaneously has not been reported. The data from this case could provide essential insights into the variations in the extensor digitorum profundus complex in humans and non-human primates.

Nerves in quadratus lumborum planes: A cadaveric study.

Dermatomal analgesia achieved with quadratus lumborum blocks is site-dependent and inconsistent. Cadaveric and clinical studies reveal multiple mechanisms of action. We dissected six fresh human cadavers bilaterally and thoroughly studied their neurological linkages to the quadratus lumborum muscle (QLM) to identify neural structures and block targets. At the end of the investigation, only the subcostal nerve (anterolateral) and the ilioinguinal nerves were found near the QLM in all specimens. The iliohypogastric nerve was found in only two specimens. No further neural targets were found in the fascial planes before and posterior to the QLM.

Navigating the layers of concern for safe dry needling of the rectus abdominis: a cadaveric study.

OBJECTIVES: To assess needle placement accuracy in the rectus abdominis (RA) muscle during dry needling (DN) without entering the peritoneum. METHODS: Two physical therapists performed DN on a cadaver, making 10 attempts each to needle the RA without entering the peritoneum. Techniques followed two common DN approaches. Ultrasound verified needle depth and safety. RESULTS: Seventy percent of attempts were recorded as safe needle placement, while 30% were unsafe. Accurate RA needle placement without peritoneal entry occurred in 55% of attempts. DISCUSSION/CONCLUSION: Inadvertent peritoneal needle placement during RA DN poses risks regardless of experience. Ultrasound guidance may enhance safety and precision in clinical practice.

Anatomical variations and embryological basis of arch of aorta and aortic valve.

Variations in the arch of the aorta and aortic valves among fetal, cadaveric, and post-mortem specimens present a spectrum of anatomical configurations, posing challenges in establishing a standard norm. While some variations hold surgical significance, many bear little functional consequence but provide insights into embryological origins. The aortic arch exhibits diverse branching patterns, including common trunks and different orders, relevant for endovascular surgeries. Meanwhile, malformations in the aortic valve, affecting the aorta, may lead to ischemia and cerebral infarction, warranting understanding of coexisting arch and valve anomalies to predict complications like aortic dissection. Studies in the Indian population mirror global variations, underscoring the need to explore embryological, clinical, and surgical implications for safer vascular surgeries involving the aortic arch and valves. The study's objectives included examining branching patterns, diameters, and distances between arch branches and exploring aortic valve variations. Employing a cross-sectional design, the study was conducted across Anatomy, Forensic Medicine, and Obstetrics and Gynecology departments. A sample of 100, comprising cadavers, fetuses, and postmortem specimens, were gathered. Specimens ranged from 14 weeks of intrauterine life to 85 years, with intact thoracic cages as inclusion criteria. Methodology involved dissection, specimen fixation, and macroscopic examination for variations and morphological parameters. Results showed aortic diameter increase with age, with significant gender differences. A statistically significant association between arch variations and anomalous valves was observed, suggesting mutual predictability. Individuals with valve anomalies should undergo comprehensive cardiology evaluation to avert complications like aortic dissection during endovascular surgeries. While atheromatous plaques were prevalent in younger groups, their frequency rose with age, necessitating vigilant vascular monitoring. Careful handling during surgeries is paramount, given potential adverse outcomes resulting from variations. Overall, the study underscores the importance of comprehensive anatomical understanding in clinical contexts, guiding effective management strategies and ensuring patient safety in vascular surgeries.

The Spiral of Tillaux: dead on accurate; a cadaveric study.

INTRODUCTION: The Spiral of Tillaux describes the historically accepted insertion distances of the medial rectus, inferior rectus, lateral rectus, and superior rectus from the limbus: 5.5 mm, 6.5 mm, 6.9 mm, and 7.7 mm, respectively. The corneal diameters are historically accepted to be 11.7 mm horizontally and 10.6 mm vertically in adults. We investigated the variability of the insertion distances of the extraocular rectus muscles from the limbus as well as the corneal diameters using eyes from human cadavers and compared our measurements to these historically accepted measurements. METHODS: A sample of 60 eyes were included. For each eye, a 360 peritomy was conducted and the conjunctiva bluntly dissected to view the sclera. Muscle hooks were utilized to isolate the extraocular rectus muscles. Calipers were used to measure the insertion distances of the rectus muscles as well as the corneal diameters. RESULTS: The mean rectus muscle insertions distances from the limbus were medial 5.28 mm, inferior 5.72 mm, lateral 6.40 mm, and superior 6.78 mm. These insertion distances were shorter than the historical benchmarks (p < .01). However, observed maximum distances of the rectus muscles were all greater than the historically accepted benchmarks, with the medial, inferior, lateral, and superior rectus muscles being 6.4 mm, 7.3 mm, 7.4 mm, and 7.8 m from the limbus, respectively. The mean width and height of the cornea were 11.7 mm and 10.7 mm, respectively, and similar to the expected ranges. CONCLUSION: This study concludes that variability does exist from the historically accepted Spiral of Tillaux measurements. In addition, significant variation exists between male and female rectus muscle insertions. However, we did confirm that the rectus muscles followed the same spiral pattern described by the Spiral of Tillaux and concluded that the corneal diameters are consistent with previously accepted values.

Dorsal calcaneal wedge removal in zadek osteotomy: A cadaveric study.

BACKGROUND: Insertional Achilles tendinopathy (IAT) is a common pathology with multiple surgical interventions available for treatment. The Zadek, dorsal closing wedge calcaneal osteotomy (ZO) has been demonstrated to be effective treatment of IAT. There have been various recommendations in the literature as to what measurement of wedge removal should be considered ideal to produce greatest postoperative range of motion (ROM), thus postoperative biomechanical potential. Accordingly, the purpose of this cadaveric study was to assess the range of motion achieved after various measurements of wedge removal by ZO. METHODS: The ZO was performed on six cadaveric specimens. A 7.5 mm and 15 mm wedge osteotomy was marked and sequentially completed on each specimen. Lateral fluoroscopic imaging was utilized to take preoperative and postoperative ROM measurements for each osteotomy. Dorsiflexion (DF) and plantarflexion (PF) ROM arcs were measured for each wedge size and compared by t-test. Effect sizes were calculated by Cohen's d analysis. RESULTS: Maximal DF was 110.87 ± 12.97 deg in the pre-osteotomy state. Removal of a 7.5 mm wedge improved DF by 8 deg to a mean 102.93 ± 13.81 deg (p = 0.08). Removal of a 15 mm wedge improved DF by 16 deg to a mean 95.96 ± 11.41 deg (p = 0.003). Cohen's d and effect size calculation demonstrated a 7.5 mm wedge to have a small effect on DF, while a 15 mm wedge had a medium effect (0.29, 0.52 respectively). Maximal PF did not change significantly amongst the pre-osteotomy, 7.5 mm wedge, or 15 mm wedge positions. ICC was 0.96. CONCLUSION: Based on the results presented in this study, removal of a 15 mm wedge with ZO yields significant and greater improvement in ROM than a 7.5 mm wedge. We hope the current study will better inform preoperative planning for ZO. STUDY TYPE: Prospective Cadaver Study. LEVEL OF EVIDENCE: V.

Anatomic variations of the deltoid muscle insertion: a cadaveric study.

Background: The deltoid is a trisegmented muscle with anterior, middle, and posterior components. While the clinical relevance of the presence of anatomic variations of the deltoid origin and insertion continues to be debated, the architecture of the deltoid muscle is more complex than initially believed. This study aimed to evaluate the gross anatomy of the deltoid muscle insertion by qualitatively and quantitatively characterizing the insertion and location of the deltoid muscle's anterior, middle, and posterior components. This information is valuable to surgeons as it raises awareness of potential variants that could be encountered during surgery, promotes mindfulness of neurovascular proximities, and reduces the likelihood of confusion between adjacent muscle fibers. Methods: Eight nonpaired, fresh-frozen clavicle-to-fingertip cadaveric shoulders were acquired for the study (6 left, 2 right). The average age of the cadavers was 79.5 years (range: 64-92). The standard deltopectoral approach was carried out on all specimens. The planes dividing the anterior, middle, and posterior deltoid were identified and marked. Once complete exposure had been achieved, digital calipers were used to record the size of the deltoid insertion. The specimens were qualitatively assessed to characterize the style of insertion they demonstrated. Results: The average length of the deltoid insertion was 39.45 ± 9.33 mm (n = 8). Six of the eight shoulders demonstrated an insertion style previously characterized in the literature. The remaining two shoulders highlighted an insertion pattern not previously described. Conclusion: The current study demonstrates a novel insertion pattern for the deltoid muscle that has not been previously characterized. This "step-off" insertion pattern shows that the anterior, middle, and posterior tendons are inserted superior-medial, directly on, and inferior-lateral to the deltoid tuberosity and was found in 2/8 of our cadaveric specimens.

Evaluation of patients diagnosed with brain death in the intensive care unit: 10 years of tertiary center experience in Istanbul.

OBJECTIVE: Early and accurate diagnosis of brain death in intensive care units (ICU) is essential for organ transplantation. This study aimed to evaluate the cases diagnosed with brain death in the ICU of a tertiary center in Istanbul. METHODS: The cases diagnosed as brain death in the ICU during the ten years between January 2013 and September 2022 were evaluated retrospectively. The demographic characteristics of the patients, the diagnosis of hospitalization in the ICU, the time from arrival to the ICU until the diagnosis of brain death, the somatic survival time after the diagnosis of brain death, the acceptance rate of organ donation by the families and the organs removed were evaluated. RESULTS: A total of 44 patients were diagnosed with brain death. The mean age of the cases was 39.7±17.4 years, and 63% were male. The most common hospitalization diagnosis was intracranial hemorrhage (81.8%). Traffic accidents, hypertensive and aneurysm-related hemorrhages, gunshot wounds, and falls from height were the most common causes of intracranial hemorrhage. Patients were admitted to the ICU most frequently from the emergency department (54%). The mean time to brain death was 7.9±6.2 days, and the somatic survival time was 1.9±1.9 days in patients who did not receive organ transplantation. While the apnea test was positive in 91% of the cases, the apnea test could not be completed in 9% of the cases. While relatives of 7% (n=3) of the cases accepted organ donation, a patient was not allowed to be an organ donor for medical reasons. Organ transplantation was performed in two patients (5%). CONCLUSION: As in the whole world, getting treatment as soon as possible for the patients waiting on the organ transplant list in Turkiye by increasing the number of organs to be obtained from cadavers. In cases with suspected brain death in the ICU, diagnosing brain death as soon as possible and conducting family interviews with trained organ transplant coordinators will increase the number of cadaver donors. However, we think policies should be developed to ensure that society is informed and encouraged about brain death and organ donation.

The Safety of Volar to Dorsal Percutaneous Screw Fixation of Bennett Fracture-Dislocation - A Cadaveric Study.

Background: Bennett fractures are traditionally fixed with percutaneous K-wires from dorsal to volar, or with a volar to dorsal screw via a volar open approach. While volar to dorsal screw fixation is biomechanically advantageous, an open approach requires extensive soft tissue dissection, thus increasing morbidity. This study aims to investigate the practicality and safety of Bennett fracture fixation using a percutaneous, volar to dorsal screw, particularly with regard to the median nerve and its motor branch during wire and screw insertion. Methods: Fifteen fresh frozen forearm and hand specimens were obtained from the University of Auckland human cadaver laboratory. A guidewire is placed under image intensifier from volar to dorsal with the thumb held in traction, abduction and pronation. The wire is passed through the skin volarly under image intensifier, then the median nerve is dissected from the carpal tunnel and the motor branch of the median nerve (MBMN) is dissected from its origin to where it supplies the thenar musculature. The distance between the K-wire to the MBMN is measured. Results: In 14 of 15 specimens, the wire was superficial and radial to the carpal tunnel. The mean distance to the origin of the MBMN is 6.2 mm (95% CI 4.1-8.3) with the closest specimen 1 mm away. The mean closest distance the wire gets to any part of the MBMN is 3.7 mm (95% CI 1.6-5.8); in two specimens, the wire was through the MBMN. Conclusions: Wire placement, although done under image intensifier, is subject to significant variation in exiting location. While research has shown the thenar portal in arthroscopic thumb surgery is safe, our guidewire needs to exit further ulnar to capture the Bennett fracture fragment, placing the MBMN at risk. This cadaveric study has demonstrated the proposed technique is unsafe for use.

Tracheal Deviation and Airway Management: Clinical Considerations From a Cadaver.

Severe tracheal deviation detected on preoperative chest radiographs is one of the risk factors for difficult tracheal intubation and difficulty in ventilation using an endotracheal tube after tracheal intubation when managing the airway through tracheal intubation under general anesthesia. In this report, we describe the cadaver of an 81-year-old woman with marked tracheal deviation due to meandering multiple aortas. This report details the importance of anatomical knowledge in developing a detailed airway management plan. The deviated trachea was removed from the cadaver and the tracheal tube was inserted at the glottis to the proximal end of the glottal marker. The tube tip was in contact with the tracheal wall, suggesting ventilation difficulty during intubation. The tortuous brachiocephalic artery passed in front of the trachea, which posed a risk of massive aortic hemorrhage and postoperative trachea-brachiocephalic artery fistula during percutaneous tracheostomy for emergency airway management. The anatomical location of the trachea and carotid artery must be confirmed before surgery/anesthesia to ensure safe airway management.

A Triad of Intricacies: An Exploration of Concomitant Codominant Coronary Artery Pattern, Patent Foramen Ovale, and Chiari Network in a Cadaveric Study.

Although findings related to codominant coronary artery circulation, patent foramen ovale (PFO), and Chiari network (CN) have been documented in isolation, there is a gap in literature detailing the unique case with the presence of all three cardiac anomalies concomitantly present in a single heart. The purpose of this case report is to detail a unique cadaveric heart case, to serve as reference to provide useful data for interventionalists and clinicians. This observational cadaveric study assessed a single donor heart obtained through the University of Houston College of Medicine's Willed Donor Program. After meticulous dissection, relevant heart surface structures were isolated and identified. Morphometric analysis and measurements were obtained via a digital vernier caliper. The donor heart exhibited a typical codominant coronary arterial scheme, in that the posterior interventricular artery arose as a merger between the right coronary and the circumflex on the postero-inferior surface of the heart when placed in the valentine orientation. Interestingly, the antero-lateral surface of the heart was supplied via a left marginal artery (LMA) and an accessory left anterior interventricular artery.Contribution to the existing knowledge base of unique concomitant cardiac anomalies, may prove to be a beneficial future reference for interventionalists in hopes that an expanded knowledge base may lead to comprehensive and safe implementation of a wide variety of procedures.

Diatoms in maggots; a potential tool for drowning diagnosis - A preliminary study.

Advanced putrefaction causes extensive loss of soft tissue, rendering it difficult to use the diatom test as a reliable diagnostic tool for drowning investigations. A positive diatom test in carrion insect larvae may provide significant assistance in overcoming the challenge of decomposition. The studies determined the utility of diatom test in carrion larvae on severely decomposed bodies. A modified acid digestion method involving nitric acid, K2Cr2O7 and HCl, was used to digest the blowfly larvae feeding on piglet carrion previously drowned in freshwater and sea water, respectively. Extracted diatom frustules were analysed and characterised using light microscopy coupled to a digital camera. Diatoms recovered from maggots on sea-drowned piglets were similar to diatoms from sea water (drowning medium). Centric diatoms recovered in maggots were higher (200 ± 60 diatoms/ mL) than pennate diatoms (80 ± 20 diatoms/mL). Isolated diatoms common to both maggots and water samples included Coscinodiscus sp. and Navicular spp. Albeit, there were no diatoms recovered from maggots on freshwater-drowned piglets. The findings of this study suggest that the diatom test is still a reliable diagnostic tool to determine if drowning was involved in the death of a fully decomposed body. This is the first study that isolated diatoms from maggots feeding on drowned bodies. It serves as the basis for further research into the utility of maggots for drowning investigations.

Assessing the Utilization and Effectiveness of YouTube in Anatomy Education Among Medical Students: A Survey-Based Study.

Introduction Learning methodologies, particularly in medical education, are evolving with the integration of internet-based technologies into daily life. As a platform, YouTube has become a significant tool for studying human anatomy among medical students. This study aims to assess the utilization of YouTube in learning human anatomy, the types of audio-visual materials used, and the platform's perceived effectiveness in understanding and memorizing anatomical information. Methods A cross-sectional questionnaire study was conducted among 200 medical students at a medical college over one year, of whom 195 completed the questionnaire and were included. The questionnaire addressed general YouTube usage, specific usage for medical studies and human anatomy, types of audio-visual materials used, and the perceived effectiveness of YouTube in understanding and memorizing anatomical information. Data were analyzed using IBM SPSS Statistics for Windows, Version 25.0 (IBM Corp., Armonk, NY) for Pearson's chi-square test to determine statistical differences based on gender and year of study. Results The study cohort comprised 195 medical students (average age: 19.8±1.1 years), 62.6% females and 37.4% males. YouTube emerged as extensively utilized, with 94.5% of males and 96.7% of females reporting general usage and 91.8% of males and 89.3% of females utilizing it for medical studies. For human anatomy learning, 93.2% of males and 89.3% of females relied on YouTube. Among the audio-visual materials, PowerPoint presentations were most prevalent, favored by 46.5% of males and 41.8% of females. Regarding effectiveness, 82.1% of males and 83.7% of females affirmed YouTube's enhancement of anatomical understanding, with 89% of males and 85.3% of females acknowledging its aid in memorization. Additionally, 90.4% of males and 87.3% of females recommended YouTube as an anatomy learning tool. Despite observed gender-based preferences for specific content types, no statistically significant differences were discerned in YouTube's usage and perception across genders. Conclusions YouTube is a widely used and effective tool for the study of human anatomy among medical students, facilitating the understanding and memorization of anatomical information. While cadaver dissection remains an irreplaceable part of medical education, the addition of YouTube as a learning resource can enhance the educational experience. Future research should focus on the in-depth exploration of content satisfaction and the potential role of YouTube in the broader anatomy curriculum.

Development of a deep-learning algorithm for age estimation on CT images of the vertebral column.

PURPOSE: The accurate age estimation of cadavers is essential for their identification. However, conventional methods fail to yield adequate age estimation especially in elderly cadavers. We developed a deep learning algorithm for age estimation on CT images of the vertebral column and checked its accuracy. METHOD: For the development of our deep learning algorithm, we included 1,120 CT data of the vertebral column of 140 patients for each of 8 age decades. The deep learning model of regression analysis based on Visual Geometry Group-16 (VGG16) was improved in its estimation accuracy by bagging. To verify its accuracy, we applied our deep learning algorithm to estimate the age of 219 cadavers who had undergone postmortem CT (PMCT). The mean difference and the mean absolute error (MAE), the standard error of the estimate (SEE) between the known- and the estimated age, were calculated. Correlation analysis using the intraclass correlation coefficient (ICC) and Bland-Altman analysis were performed to assess differences between the known- and the estimated age. RESULTS: For the 219 cadavers, the mean difference between the known- and the estimated age was 0.30 years; it was 4.36 years for the MAE, and 5.48 years for the SEE. The ICC (2,1) was 0.96 (95 % confidence interval: 0.95-0.97, p < 0.001). Bland-Altman analysis showed that there were no proportional or fixed errors (p = 0.08 and 0.41). CONCLUSIONS: Our deep learning algorithm for estimating the age of 219 cadavers on CT images of the vertebral column was more accurate than conventional methods and highly useful.

Biomechanical Effects of Hindfoot Alignment in Supination External Rotation Malleolar Fractures: A Human Cadaveric Model.

BACKGROUND: Pressure distribution in the ankle joint is known to be dependent on various factors, including hindfoot alignment. We seek to evaluate how hindfoot alignment affects contact pressures in the ankle joint in the setting of supination external rotation (SER) type ankle fractures. METHODS: SER fractures were created in 10 human cadaver lower extremity specimens, simulating progressive stages of injury: without fracture (step 0), SER fracture and intact deltoid ligament (step 1), superficial deltoid ligament disruption (step 2), and deep deltoid ligament disruption (step 3). At each step, varus and valgus alignment was simulated by displacing the calcaneal tuberosity 7 mm medial or lateral. Each limb was axially loaded following each osteotomy at a static load of 350 N. The center of force (COF), contact area (CA), and peak contact pressure (PP) under load were measured, and radiographs of the ankle mortise were taken to analyze the medial clear space (MCS) and talar tilt (TT). RESULTS: The COF (5.3 mm, P = .030) and the CA (-188.4 mm2, P = .015) changed in step 3 in the valgus hindfoot alignment compared to baseline parameters, indicating the importance of deep deltoid ligament integrity in maintaining normal ankle joint contact stress in the valgus hindfoot. These changes were not seen in the setting of varus alignment (COF: 2.3 mm, P = .059; CA -121 mm2, P = .133). PP were found to not change significantly in either varus or valgus (varus: -4.9 N, P = .132; valgus: -4 N, P = .464).The MCS demonstrated widening in step 3 compared to step 2 (0.7 mm, P = .020) in both varus and valgus hindfoot. The TT increased significantly in step 3 in the valgus hindfoot (2.8 degrees, P = .020) compared to step 0. CONCLUSION: SER-IV fractures with valgus hindfoot alignment showed significant changes in pressure distribution and radiographic parameters when compared to SER-IV fractures with varus hindfoot alignment. CLINICAL RELEVANCE: Based on this cadaver modeling study, patients with SERIV fracture with varus hindfoot alignment and complete deltoid ligament lesion may not need fracture fixation, whereas those with valgus hindfoot alignment likely need fracture fixation.

Evaluating the effect of pulse energy on femtosecond laser trabeculotomy (FLT) outflow channels for glaucoma treatment in human cadaver eyes.

BACKGROUND AND OBJECTIVES: Femtosecond laser trabeculotomy (FLT) creates aqueous humor outflow channels through the trabecular meshwork (TM) and is an emerging noninvasive treatment for open-angle glaucoma. The purpose of this study is to investigate the effect of pulse energy on outflow channel creation during FLT. MATERIALS AND METHODS: An FLT laser (ViaLase Inc.) was used to create outflow channels through the TM (500 µm wide by 200 µm high) in human cadaver eyes using pulse energies of 10, 15, and 20 µJ. Following treatment, tissues were fixed in 4% paraformaldehyde. The channels were imaged using optical coherence tomography (OCT) and assessed as full thickness, partial thickness, or not observable. RESULTS: Pulse energies of 15 and 20 µJ had a 100% success rate in creating full-thickness FLT channels as imaged by OCT. A pulse energy of 10 µJ resulted in no channels (n = 6), a partial-thickness channel (n = 2), and a full-thickness FLT channel (n = 2). There was a statistically significant difference in cutting widths between the 10 and 15 µJ groups (p < 0.0001), as well as between the 10 and 20 µJ groups (p < 0.0001). However, there was no statistically significant difference between the 15 and 20 µJ groups (p = 0.416). CONCLUSIONS: Fifteen microjoules is an adequate pulse energy to reliably create aqueous humor outflow channels during FLT in human cadaver eyes. OCT is a valuable tool when evaluating FLT.

The development of a novel navigation system for reverse shoulder arthroplasty and its accuracy: a phantom and cadaveric study.

PURPOSE: Reverse shoulder arthroplasty has demonstrated excellent clinical efficacy for patients with shoulder joint diseases and is increasingly in demand. Traditional surgery faces challenges such as limited exposed surfaces and a narrow field of vision, leading to a shorter prosthesis lifespan and a higher risk of complications. In this study, an optical navigation system was proposed to assist surgeons in real-time tracking of the surgical scene. METHODS: Our optical navigation system was developed using the NDI Polaris Spectra device and several open-source platforms. The first step involved using the preoperative medical image to plan screw implantation paths. Real-time tracking of the patient phantom or cadaver and the surgical instrument was achieved through registration and calibration algorithms. Surgeons were guided on drilling through visualization methods. Postoperative results were compared with the planned implantation paths, and an algorithm was introduced to correct errors caused by the incorrect beginning points. RESULTS: Experiments involved three scapula cadavers and their corresponding phantoms with identical anatomy. For each experiment, three holes were completed with drills with diameters of 3.2 mm and 8.0 mm, respectively. Comparisons between the postoperative actual screw implantation paths and the preoperative planned implantation paths revealed an entry error of 1.05 ± 0.15 mm and an angle error of 2.47 ± 0.55° for phantom experiments. For cadaver experiments, the entry error was 1.53 ± 0.22 mm, and the angle error was 4.91 ± 0.78°. CONCLUSION: Our proposed optical navigation system successfully achieved real-time tracking of the surgical site, encompassing the patient phantom or cadaver and surgical instrument, thereby aiding surgeons in achieving precise surgical outcomes. Future study will explore the integration of robots to further enhance surgical efficiency and effectiveness.

Novel Muscle in Infraspinous Fossa.

The infraspinatus muscle (IS) makes a minor contribution to lateral rotation of the arm but mainly serves to stabilize the glenohumeral (GH) joint as part of the rotator cuff. Although reports of variations in the rotator cuff muscles have been documented previously, specific discussions of IS variants are lacking. In this report, we present a novel case of an accessory muscle in the infraspinous fossa and its relationship to the IS, which was normally located. We describe the observed physical features of the muscles and their innervation patterns.