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The aim of this review was to report on the imaging modalities used to assess morphological and architectural properties of the m. triceps surae muscle in typically developing children, and the available reliability analyses. Scopus and MEDLINE (Pubmed) were searched systematically for all original articles published up to September 2020 measuring morphological and architectural properties of the m. triceps surae in typically developing children (18 years or under). Thirty eligible studies were included in this analysis, measuring fibre bundle length (FBL) (n = 11), pennation angle (PA) (n = 10), muscle volume (MV) (n = 16) and physiological cross-sectional area (PCSA) (n = 4). Three primary imaging modalities were utilised to assess these architectural parameters in vivo: two-dimensional ultrasound (2DUS; n = 12), three-dimensional ultrasound (3DUS; n = 9) and magnetic resonance imaging (MRI; n = 6). The mean age of participants ranged from 1.4 years to 18 years old. There was an apparent increase in m. gastrocnemius medialis MV and pCSA with age; however, no trend was evident with FBL or PA. Analysis of correlations of muscle variables with age was limited by a lack of longitudinal data and methodological variations between studies affecting outcomes. Only five studies evaluated the reliability of the methods. Imaging methodologies such as MRI and US may provide valuable insight into the development of skeletal muscle from childhood to adulthood; however, variations in methodological approaches can significantly influence outcomes. Researchers wishing to develop a model of typical muscle development should carry out longitudinal architectural assessment of all muscles comprising the m. triceps surae utilising a consistent approach that minimises confounding errors.

Objective In the present study, we sought to investigate the in vivo musculoaponeurotic architecture of the masseter muscle (MM) volumetrically with ultrasound in asymptomatic participants. It was hypothesized that the mean fiber bundle length (FBL) and mean aponeurotic height of laminae of the MM differ significantly between the relaxed state and maximally contracted state upon elevation of the mandible. Study Design The MM was investigated volumetrically in 12 male and 12 female asymptomatic participants (mean age, 25.8 ± 4.1 years) using ultrasound. The mean FBL and mean height of aponeuroses in the relaxed and maximally contracted states were compared using paired t tests, with significance established at P ≤ .05. Intrarater reliability was assessed using the intraclass correlation coefficient (ICC). Results The MM consisted of the superficial head (SH) and deep head, each arranged in multiple laminae. Fiber bundles extended between superior and inferior aponeuroses and/or bone. Statistically significant differences (P ≤ .05) were observed in mean FBL and in mean height of aponeuroses between the relaxed and contracted states only in superficial laminae of the SH. Conclusions These results suggest there is differential contraction of the laminae of the MM in the transition from relaxed to contracted states. Future comparison with pathologic patients can be made on the basis of an established normative database.

Background and objectivesRadiofrequency (RF) denervation of the superolateral genicular nerve (SLGN), superomedial genicular nerve (SMGN) and inferomedial genicular nerve (IMGN) is commonly used to manage chronic knee joint pain. However, knowledge of articular branches captured, using classical landmarking techniques, remains unclear. In order to enhance and propose new RF procedures that conceivably capture a greater number of articular branches, more detailed cadaveric investigation is required. The objectives were to (1) determine which articular branches are captured or spared using classical landmarking techniques, and (2) evaluate the anatomical feasibility of classical landmarking techniques using three-dimensional (3D) modeling technology.MethodsUltrasound-guided classical superolateral/superomedial/inferomedial landmarking techniques were used to position RF cannulae in five specimens. The articular branches, bony and soft tissue landmarks, and cannula tip position, were meticulously dissected, digitized and modeled in 3D. Simulated lesions were positioned at the cannula tip, on the 3D models, to determine which articular branches were captured or spared. Capture rates of articular branches were compared.ResultsIn all specimens, classical superolateral/superomedial techniques captured the transverse deep branches of SLGN and SMGN, and articular branches of lateral and medial nerve to vastus intermedius, while sparing distal branches of SLGN/SMGN. The inferomedial technique captured anterior branches of IMGN while sparing the posterior and inferior branches.ConclusionsThis study provides anatomical evidence supporting the effectiveness of classical landmarking for genicular nerve ablation; however, each technique resulted in sparing of articular branches. The extensive innervation of the knee joint suggests the use of supplementary landmarks to improve capture rates and potentially patient outcomes.

Facial paralysis can severely impact functionality and mental health. Facial reanimation surgery can improve facial symmetry and movement. Zygomaticus minor (Zmin) and zygomaticus major (Zmaj) are 2 important perioral muscles, that function to elevate the upper lip, contributing to the formation of a smile. The objective of this study was to analyze the morphology in three-dimensional (3D) and quantify architectural parameters of Zmin and Zmaj. In ten formalin-embalmed specimens, Zmin and Zmaj were serially dissected and digitized at the fiber bundle level. The 2 muscles were modeled in 3D to construct high fidelity models. The 3D models were used to assess muscle morphology and quantify architectural parameters including mean fiber bundle length, physiological cross-sectional area, and line of action. Zygomaticus minor fiber bundles were oriented horizontally or slightly obliquely and had a muscular attachment to the medial modiolus. Zygomaticus minor was found to either have no partitions or medial and lateral partitions. Specimens with partitions were divided into type 1 and type 2. Type 1 consisted of a medial partition with fiber bundles attaching to the zygomatic bone at the inferior margin of the orbit. The type 2 medial partition attached to the lateral margin of the orbit to attach to the zygomatic bone. Zygomaticus major had obliquely oriented fiber bundles with most specimens having inferior and superior partitions attaching to the inferior aspect of the zygomatic bone. Zygomaticus major was found to have a greater mean fiber bundle length and physiological cross-sectional area than Zmin. The direction of the line of action of Zmin and Zmaj was closely related to fiber bundle arrangement. Detailed 3D anatomical understanding of Zmin and Zmaj, at the fiber bundle level, is critical for reconstructive surgeons performing dynamic facial reanimation. This data can be used to assist with selecting the ideal donor site for reconstruction.

The innervation of the hip joint has been investigated for over 200 years by anatomists and clinicians. Knowledge of the distribution and location of these nerves relative to anatomic landmarks visible with image guidance is important for optimizing nerve blocks and radiofrequency ablation procedures. In this article, the innervation of the anterior and posterior hip joint is reviewed, focusing on the source of articular branches, their course, termination, and relationship to anatomic landmarks. The innervation of the hip joint is multifaceted, with articular nerves originating from many sources in close proximity to and distant from the hip joint.

Detailed understanding of the course and location of articular nerves supplying the shoulder joint is paramount to the successful utilization of image-guided radiofrequency ablation to manage chronic shoulder pain. In this article, the origin, course, and relationship to anatomic landmarks of articular nerves supplying the shoulder and acromioclavicular joints are discussed. The shoulder joint capsule was consistently reported to receive innervation from multiple sources including the suprascapular, axillary, subscapular, and lateral pectoral nerves. The acromioclavicular joint received innervation from suprascapular and lateral pectoral nerves. The consistent relationship of articular branches to anatomic landmarks provides the basis for specific image-guided targeting.

In this article, the literature describing the origin, course, and termination of the nerves innervating the ankle joint is reviewed and discussed. The anterior aspect of the joint capsule receives innervation from articular branches from the saphenous, superficial, and deep fibular nerves; laterally from the sural and superficial fibular nerves; and medially and posteriorly from the saphenous and tibial nerves. Comprehensive mapping of the trajectory, spatial relationships, and termination of the articular branches innervating the ankle joint capsule will aid in developing new and improving existing image-guided nerve block and radiofrequency ablation protocols to treat chronic joint pain.

Although a maxillary nerve (MN) block reportedly provides satisfactory analgesia for midface surgery and chronic maxillofacial pain syndromes, a safe and reliable MN block technique has not been reported. The goal of this anatomical study was to quantify the various angles and depth of the block needle, as well as to evaluate the impact of volume on the extent of injectate spread that might influence anesthetic coverage and block-related complications. Following an ultrasound-guided suprazygomatic MN block with dye injection, a dissection was performed in the pterygopalatine fossa (PPF) of four lightly embalmed cadaveric specimens. Half of the specimens were injected with 5 mL of dye, and the other half with 1 mL of dye. The needle depth was measured from the ultrasound images and using rubber markers. Following injection, dissection was performed to map the area of dye spread. The median [interquartile range (IQR)] distance from the skin to the PPF was 37 [36–43] mm and 47 [40–50] mm by ultrasound and rubber marker methods, respectively. The median [IQR] needle orientation was 14 [11–32] degrees inferiorly and 15 [10–17] degrees posteriorly. The PPF was consistently dyed in the 5 mL group, but sporadically dyed in the 1 mL group. In the 5 mL group, spread outside of the PPF was seen. We showed that 5 mL of injectate far exceeds the capacity of the PPF, leading to drug spread outside of the PPF. Moreover, we found that 1 mL of injectate largely covered the nerve, suggesting a more efficacious and safer block procedure. This finding will need confirmation in future clinical studies.

Background: Open carpal tunnel release typically requires several weeks of recovery. A less invasive, ultrasound-guided percutaneous technique of releasing the transverse carpal ligament using a thread (thread carpal tunnel release [TCTR]) has been described. To date, its clinical effectiveness and safety have been evaluated exclusively by the group that developed the technique, using a single outcome measure without a control comparison. The objective of this study was to independently evaluate the safety and effectiveness of TCTR using multiple outcome measures and a control comparison. Methods: A convenience sample of 20 participants with refractory moderate or severe carpal tunnel syndrome underwent TCTR of their most symptomatic hand. Outcome measures included pre-TCTR and 1-, 3-, and 6-month post-TCTR Boston questionnaire; pre-, 3-, and 6-month post-TCTR monofilament sensibility, strength, ultrasound, and electrodiagnostic testing; weekly post-TCTR phone interviews for 1 month; and satisfaction surveys at 3 and 6 months post-TCTR. Results: No complications were reported. During the month post-TCTR, significant prompt improvements in hand pain and dysfunction occurred. The following significant improvements were demonstrated in the treated versus control hand: Boston Questionnaire scores, median nerve distal motor latency, transcarpal tunnel motor and sensory conduction velocities and sensory nerve action potential amplitudes. No significant differences in sensibility, pinch or grip strength, median nerve cross-sectional area (CSA) at the carpal tunnel inlet, or wrist: forearm median nerve CSA ratio were documented between TCTR and control sides. Satisfaction with the TCTR procedure was high (85%-90%). Conclusions: This study supports previous reports that the TCTR procedure is safe and effective.

Background and purpose: Following a stroke, three-dimensional clavicular/scapular/humeral joint rotations may become restricted and contribute to post-stroke shoulder pain. This study examined whet...

Vastus medialis (VM) has two partitions, longus (VML), and obliquus (VMO), which have been implicated in knee pathologies. However, muscle architecture of VMO and VML has not been documented volumetrically. The aims of this study were to determine and compare the muscle architecture of VMO and VML in three-dimensional (3D) space, and to elucidate their relative functional capabilities. Twelve embalmed specimens were used in this study. Each specimen was serially dissected, digitized (Microscribe™ MX), and modeled in 3D (Autodesk Maya®). Architectural parameters: fiber bundle length (FBL), proximal (PPA)/distal (DPA) pennation angle, and physiological cross-sectional area (PCSA) were compared using descriptive statistics/t-tests. Sarcomere lengths (SLs) were measured and compared from six biopsy sites of VM. VMO and VML were found to have superficial and deep parts based on fiber bundle attachments to aponeuroses, medial patellar retinaculum, and adductor magnus tendon. The superficial part of VMO was further subdivided into superior and inferior partitions. Architecturally, VMO was found to have significantly shorter mean FBL, greater mean PPA and DPA, and smaller mean PCSA than VML. VML was found to be connected to the fascia lata by thin fascial bands, not present in VMO. SLs of VMO and VML were comparable. VMO and VML are architecturally and functionally distinct, as evidenced by marked differences in their musculoaponeurotic geometry, attachment sites, and architectural parameters. VMO likely contributes greater to medial patellar stabilization, whereas VML, with a larger relative excursion and force-generating capability, to the extension of the knee. Clin. Anat. 32:515-523, 2019. © 2019 Wiley Periodicals, Inc.

IntroductionHistorically, dissection is considered the ‘gold standard’ for teaching foundational anatomy to student occupational therapists. However, many programmes no longer have access to gross anatomy laboratory resources, as it is considered too costly. To address this limitation, applied anatomy instructors have developed innovative novel approaches to teach gross and applied anatomy to student occupational therapists, including live/surface anatomy, medical imaging, and more recently, computer-aided instruction. The types of different anatomy pedagogical approaches used and their impact on learning outcomes in occupational therapy education are unclear. The purpose of this scoping review is to map the types of musculoskeletal gross and applied anatomy pedagogical approaches used in occupational therapy curricula.Methods and analysisUsing Arksey and O’Malley’s (2005) six-stage scoping review framework, approximately 304 different search combinations will be searched across five electronic library databases (ie, MEDLINE, Embase, CINAHL, AMED and ERIC) from their inception to December 2021, in addition to conducting consultation exercises with relevant stakeholders. After title/abstract and full-text screening, included articles will be charted, collated and summarised.Ethics and disseminationThis study will not involve human or animal subjects. Therefore, research ethics approval is not required. The proposed scoping review will help the research, institutional and clinical rehabilitation communities to better understand the types of musculoskeletal gross and applied anatomy pedagogical approaches used to foster, build and promote musculoskeletal foundational knowledge in occupational therapy education. This could potentially inform the future physical medicine course curricula in occupational therapy programmes. The findings of this review will be disseminated to occupational therapy instructors, occupational therapists, researchers and organisations offering occupational therapy programmes (eg, Universities).

OBJECTIVE(S) To create and validate a synthetic simulator for teaching tracheostomy and laryngotracheal reconstruction (LTR) using anterior costal cartilage and thyroid ala cartilage grafts. METHODS A late adolescent/adult neck and airway simulator was constructed based on CT scans from a cadaver and a live patient. Images were segmented to create three-dimensional printed molds from which anatomical parts were casted. To evaluate the simulator, expert otolaryngologists - head and neck surgeons performed tracheostomy and LTR using anterior costal cartilage and thyroid ala cartilage grafts on a live anesthetized porcine model (gold standard) followed by the synthetic simulator. They evaluated each model for face validity (realism and anatomical accuracy) and content validity (perceived effectiveness as a training tool) using a five-point Likert scale. For each expert, differences for each item on each simulator were compared using Wilcoxon Signed-Rank tests with Sidak correction. RESULTS Nine expert faculty surgeons completed the study. Experts rated face and content validity of the synthetic simulator an overall median of 4 and 5, respectively. There was no difference in scores between the synthetic model and the live porcine model for any of the steps of any of the surgical procedures. CONCLUSION The synthetic simulator created for this study has high face and content validity for tracheostomy and LTR with anterior costal cartilage and thyroid ala cartilage grafts and was not found to be different than the live porcine model for these procedures. LEVEL OF EVIDENCE 5 Laryngoscope, 131:E2378-E2386, 2021.

Background and objectivesAcromial branches of the lateral pectoral and suprascapular nerves have been proposed as targets for diagnostic block and radiofrequency ablation to treat superior shoulder pain; however, the nerve capture rates of these procedures have not been investigated. The objectives of this study were to use dissection and 3D modeling technology to determine the course of these acromial branches, relative to anatomical landmarks, and to evaluate nerve capture rates using ultrasound-guided dye injection and lesion simulation.MethodsUltrasound-guided dye injections, targeting the superior surface of coracoid process and floor of supraspinous fossa, were performed (n=5). Furthermore, needles targeting the superior and posterior surfaces of the coracoid process were placed under ultrasound guidance to simulate needle electrode position (n=5). Specimens were dissected, digitized, and modeled to determine capture rates of acromial branches of lateral pectoral and suprascapular nerves.ResultsThe course of acromial branches of lateral pectoral and suprascapular nerves were documented. Dye spread capture rates: acromial branches of lateral pectoral and suprascapular nerves were captured in all specimens. Lesion simulation capture rates: (1) when targeting superior surface of coracoid process, the entire acromial branch of lateral pectoral nerve was captured in all specimens and (2) when targeting posterior surface of coracoid process, the acromioclavicular and bursal branches of acromial branch of suprascapular nerve were captured in all specimens; coracoclavicular branch was captured in 3/5 specimens.ConclusionsThis study supports the anatomical feasibility of ultrasound-guided targeting of the acromial branches of lateral pectoral and suprascapular nerves. Further clinical investigation is required.

Some forms of chronic pain are thought to be driven and maintained by nociceptive input, which can drive plasticity within nociceptive pathways. We have previously identified abnormalities along the entire nociceptive pathway in chronic myalgic temporomandibular disorders (mTMD), including the trigeminal nerves, brainstem pathways, and in the thalamus and somatosensory cortex. These data suggest that there is a peripheral nociceptive drive in mTMD, but the source of this nociceptive activity remains unknown. Here, our aim was to determine whether structural abnormalities exist in the muscles of mastication of patients with chronic mTMD. Specifically, we tested whether the volume of the temporalis muscle and its tendon-aponeurosis complex (TAC, a structure that dissipates forces in a muscle) in mTMD patients differ compared to age- and sex-matched controls. To do so, we segmented these structures on T1-weighted structural magnetic resonance images. We found that muscle volumes in mTMD were not different to controls. However, the mTMD group had significantly smaller volumes of the bilateral temporalis TAC, and thus a smaller TAC-to-muscle volume ratio. These findings were consistent across 2 independent cohorts of 17 mTMD patients, compared to 17 age- and sex-matched controls. We propose a model where reduced TAC-to-muscle ratio could result in a predisposition to muscle tissue injury. In sum, abnormalities of the temporalis muscles in mTMD supports our hypothesis that chronic mTMD pathophysiology may be related to peripheral nociceptive barrage originating from the muscles of mastication.

Computational studies can be used to support the development of peripheral nerve interfaces, but currently use simplified models of nerve anatomy, which may impact the applicability of simulation results. To better quantify and model neural anatomy across the population, we have developed an algorithm to automatically reconstruct accurate peripheral nerve models from histological cross-sections. We acquired serial median nerve cross-sections from human cadaveric samples, staining one set with hematoxylin and eosin (H&E) and the other using immunohistochemistry (IHC) with anti-neurofilament antibody. We developed a four-step processing pipeline involving registration, fascicle detection, segmentation, and reconstruction. We compared the output of each step to manual ground truths, and additionally compared the final models to commonly used extrusions, via intersection-over-union (IOU). Fascicle detection and segmentation required the use of a neural network and active contours in H&E-stained images, but only simple image processing methods for IHC-stained images. Reconstruction achieved an IOU of 0.42±0.07 for H&E and 0.37±0.16 for IHC images, with errors partially attributable to global misalignment at the registration step, rather than poor reconstruction. This work provides a quantitative baseline for fully automatic construction of peripheral nerve models. Our models provided fascicular shape and branching information that would be lost via extrusion.

Background and objectives Peripheral nerve block is an important component of the multimodal analgesia for total knee arthroplasty. Novel interventional techniques of ultrasound-guided nerve block supplying the posterior knee joint capsule require knowledge of the innervation of the posterior capsule. The objectives of this cadaveric study were to determine the course, frequency, and distribution of the articular branches innervating the posterior knee joint capsule and their relationships to anatomical landmarks. Methods Fifteen lightly embalmed specimens were meticulously dissected. The origin of articular branches was identified, their frequency recorded, and the course documented in relation to anatomical landmarks. The capsular distribution of articular branches was documented and a frequency map generated. Results In all specimens, articular branches from the posterior division of the obturator and tibial nerves were found to supply the posterior capsule. Additionally, articular branches from common fibular nerve and sciatic nerve were found in eight (53%) and three (20%) specimens, respectively. The capsular distribution of tibial nerve spanned the entire posterior capsule. The posterior division of obturator nerve supplied the superomedial aspect of the posterior capsule overlapping with the tibial nerve. The superolateral aspect of the posterior capsule was innervated by the tibial nerve and, when present, the common fibular/sciatic nerves. Conclusions Frequency map of the course and distribution of the articular branches and their relationship to anatomical landmarks form an anatomical basis for peripheral nerve block approaches that provide analgesia to the posterior knee joint capsule.

Objective Long head biceps tendon peritendinous or sheath injections are routinely administered at or immediately distally to the bicipital groove. The main indication for injection remains the clinical diagnosis or treatment of biceps tendinopathy, although true inflammation of the tendon within the bicipital groove is rare. Because the tendon sheath is merely an extension of the joint cavity, it is plausible to assume that an injection into the sheath would result in intraarticular spread. Surprisingly, such an anatomical tenet has a vague confirmation in the published clinical literature. This experiment was undertaken to investigate patterns of injectate spread when peri-tendon injection at the bicipital groove is performed. Design An experimental cadaveric study. Setting An institutional clinical anatomy laboratory. Methods Twelve ultrasound-guided methylene blue injections of the bicep tendon sheath were performed on cadaver specimens. Dissections and gross examination of staining of the internal joint surfaces were performed. Visual confirmation of the intra- and/or extra-articular spread of the injectate was performed. Results In 11 specimens, injected contrast was found spreading onto the entire internal joint surface, including glenoid cartilage. One extraarticular injection was attributable to a technical issue. Conclusions The experiment confirmed continuity of the joint capsule and the biceps tendon sheath. These results suggest a low diagnostic utility of peritendinous injections at the level of the bicep groove. Such injections would likely result in intraarticular deposit of the injectate. Nonetheless, this approach may be utilized as an alternative simplified access to the glenohumeral joint.

Objectives Although spinal cord and dorsal root ganglia stimulation may be effective for managing regional pain syndromes, a more targeted approach is perhaps more appealing for discrete anatomical structures. Chronic shoulder pain is a common musculoskeletal problem with significant socioeconomic impact. A peripheral nerve stimulation of the axillary and suprascapular nerves may prove to be effective as a long-term solution for this indication. In anticipation of the future experimental research and clinical utilization, a sound methodology for the lead placement was developed, and its feasibility is tested in a cadaveric study. Materials and methods Normal anatomy was corroborated with ultrasound scans of live models and cadaver specimens. A step-by-step ultrasound-guided implantation technique was designed. The procedure was completed targeting both the axillary and suprascapular nerves. The accuracy of the lead placement was confirmed by dissections. Results The implanted devices were found adjacent to the target nerves within 0.5-1 cm distance. Conclusions The anatomical dissections confirmed the accuracy of ultrasound-guided placement of the lead. The described method is based on normal anatomy and appeared to be reproducible by following the outlined procedural steps.

Objective To compare the percentage of sacral lateral branches (LBs) that would be captured if lesions were created by seven current sacroiliac joint (SIJ) radiofrequency ablation (RFA) techniques: three monopolar and four bipolar. Design Cadaveric fluoroscopy study. Setting Anatomy and surgical skills laboratories. Subjects Forty cadaveric SIJs. Methods LBs were exposed, radiopaque wires were sutured to LBs, and anterior-posterior fluoroscopic images through the S1 superior endplate were obtained. Lesions that would be created by 17 versions of seven current SIJ RFA techniques were mapped on the fluoroscopic images. These 17 versions were compared: 1) percentage of LBs that would be captured; 2) percentage of SIJ specimens in which 100% of LBs would be captured; and 3) percentage of LBs that would not be captured at each level (S1-S4). Results Both the mean LB and 100% capture rates were greater for the bipolar techniques (93.4-99.7% and 62.5-97.5%, respectively) than for the monopolar techniques (49.6-99.1% and 2.5-92.5%, respectively) evaluated. For the bipolar techniques, 1.5-29.2% of LBs would not be captured at S1 and 0% at S2-S4 vs 0-29.2% at S1-S4 for the cooled monopolar techniques vs 36.9-100% at S1-S4 for the conventional monopolar technique. Conclusions The findings suggest that, if lesions were created, the RFA needle placement locations of the bipolar techniques evaluated may be capable of capturing all LBs, but those of the current monopolar techniques evaluated may not. Future in vivo imaging studies are required to compare the lesion morphology generated by different SIJ RFA techniques and correlate the findings with clinical outcomes.

Purpose Suprahyoid muscles play a critical role in swallowing. The arrangement of the fiber bundles and aponeuroses has not been investigated volumetrically, even though muscle architecture is an important determinant of function. Thus, the purpose was to digitize, model in three dimensions, and quantify the architectural parameters of the suprahyoid muscles to determine and compare their relative functional capabilities. Method Fiber bundles and aponeuroses from 11 formalin-embalmed specimens were serially dissected and digitized in situ. Data were reconstructed in three dimensions using Autodesk Maya. Architectural parameters were quantified, and data were compared using independent samples t -tests and analyses of variance. Results Based on architecture and attachment sites, suprahyoid muscles were divided into 3 groups: anteromedial, superolateral, and superoposterior. Architectural parameters differed significantly ( p < .05) across muscles and across the 3 groups, suggesting differential roles in hyoid movement during swallowing. When activated simultaneously, anteromedial and superoposterior muscle groups could work together to elevate the hyoid. Conclusions The results suggest that the suprahyoid muscles can have individualized roles in hyoid excursion during swallowing. Muscle balance may be important for identifying and treating hyolaryngeal dysfunction in patients with dysphagia.

OBJECTIVE The looped thread carpal tunnel release (TCTR) procedure is a minimally invasive percutaneous technique performed under ultrasound (US) to transect the transverse carpal ligament in patients with carpal tunnel syndrome. Study objectives were to evaluate the accuracy of identifying key US landmarks, safety, effectiveness, and technical difficulty of TCTR. DESIGN Fourteen lightly embalmed cadaveric distal forearm-hand specimens were subject to US identification of key landmarks, TCTR procedure, and post-TCTR dissection. Outcome measures of interest were (1) correspondence between key landmarks (median nerve and 4 bony pillars of transverse carpal ligament) identified on US and anatomical structures exposed by dissection, (2) percentage of the transverse carpal ligament transected and location of the transection, (3) frequency of damage to adjacent structures, (4) time to complete procedure, and (5) operator assessment of technical difficulty of each TCTR procedure (0 = extremely easy, 10 = extremely difficult). RESULTS (1) Skin markings delineating the position of US-visualized landmarks corresponded almost perfectly to anatomical dissection. (2) Nine (64.2%) of 14 specimens had complete division of the transverse carpal ligament. In the remaining 5 specimens, an average of 68.8% of the ligament was transected. (3) No adjacent structures were damaged. (4) Time to complete the procedure was on average 9.9 ± 4.6 minutes. (5) Average procedural difficulty was 4.3/10. CONCLUSIONS Thread carpal tunnel release is potentially a safe, quick, and effective procedure to transect the transverse carpal ligament. Future clinical investigation is recommended.

The Toronto Video Atlas of Liver, Pancreas, Biliary, and Transplant Surgery (TVASurg) is a free online library of three-dimensional (3D) animation-enhanced surgical videos, designed to instruct surgical fellows in hepato-pancreato-biliary (HPB) and transplant procedures. The video ‘Klatskin tumours: Extended left hepatectomy with complex portal vein reconstruction and in situ cold perfusion of the liver’, which is available to watch at http://TVASurg.ca, is a unique and valuable visual resource for surgeons in training to assist them in learning this rare procedure. This paper describes the methodologies used in producing this 3D animation-enhanced surgical video.

Background and Objectives Ultrasound (US)–guided diagnostic block/radiofrequency ablation (RFA) along the lateral sacral crest (LSC) has been proposed for managing sacroiliac joint (SIJ) pain. We sought to investigate (1) ease of visualization of bony landmarks using US; (2) consistency of US-guided needle placement along the LSC; and (3) percentage of the posterior sacral network (PSN) innervating the SIJ complex that would be captured if an RFA strip lesion were created between the needles. Methods In 10 cadaveric specimens, 3 needles were placed bilaterally along the LSC from the first to third transverse sacral tubercles (TSTs) using US guidance. The PSN, SIJ, and needles were exposed, digitized, and modeled 3-dimensionally. Ease of visualization of bony landmarks, frequency of needle placement along the LSC, and percentage of the PSN that would be captured if an RFA strip lesion were created between the needles were determined. Results The LSC, TST2, TST3, and first to third posterior sacral foramina were easily visualized using US; TST1 was somewhat obscured by the iliac crest in some specimens. Needles were placed along the LSC in 18 of 20 specimens; in the first 2 of 20 specimens, needle 1 was placed at the L5/S1 facet joint. On average, 93% (95% confidence interval, 87%–98%) of the PSN would be captured if an RFA strip lesion were created between the needles. Conclusions The findings suggest that US-guided needle placement along the LSC is consistent and could capture most or all of the PSN. A clinical study evaluating the outcomes of this technique is in progress.

The transverse carpal ligament is a major component of the carpal tunnel and is an important structure in the etiology of carpal tunnel syndrome. The current study aimed to quantify biaxial elastic moduli of the transverse carpal ligament and compare differences between sex and region (Radial and Ulnar).Biaxial testing of radial and ulnar samples from twenty-two (thirteen male, nine female) human fresh frozen cadaveric transverse carpal ligaments was performed. Elastic moduli and stiffness were calculated and compared.Biaxial elastic moduli of the transverse carpal ligament ranged from 0.76MPa to 3.38MPa, varying based on region (radial and ulnar), testing direction (medial-lateral and proximal-distal) and sex. Biaxial elastic moduli were significantly larger in the medial-lateral direction than the proximal-distal direction (P0.001). Moduli were significantly larger ulnarly than radially (P=0.001). No significant differences due to gender were noted.The regional variations in biaxial elastic moduli of the transverse carpal ligament may help improve non-invasive treatment methods for carpal tunnel syndrome, specifically manipulative therapy. The smaller biaxial elastic moduli found in the radial region suggests that manipulative therapy should be focused on the radial aspect of the transverse carpal ligament. The trend where female transverse carpal ligaments had larger stiffness in the ulnar location than males suggests that that the increased prevalence of carpal tunnel syndrome in women may be related to an increased stiffness of the transverse carpal ligament, however further work is warranted to evaluate this trend.

To the Editor We read with great interest the recent publication by Fonkoue et al regarding genicular nerve ablation.[1][1] However, we are concerned with the conclusion of this paper which stated ‘This study confirms that the anatomical landmarks currently used for fluoroscopy-guided GNB need to

The infraspinatus muscle is composed of three neuromuscular partitions: superior, middle and inferior. Although methods for fine-wire EMG electrode insertion into these partitions have been developed and used, it has yet to be verified. The purpose of this cadaveric EMG needle placement study was to assess the accuracy and reproducibility of a protocol used to target the three partitions of infraspinatus. On seven shoulder specimens, two investigators inserted needles into each superior, middle and inferior partition according to a previously developed protocol. Each was blinded to the other's insertion sites. The specimens were dissected and the location of each needle was digitized and modeled in 3D. Of the 42 needles that were inserted, 32 were placed in the targeted partition. The highest accuracy rate occurred for the middle partition (100%), followed by the inferior (71.4%) and then the superior (57.1%). When the needles were not placed in the targeted partition, they were located in the neighboring partition within infraspinatus or the teres minor muscle. The current study showed the middle partition could be targeted accurately, whereas the superior and inferior partitions were more challenging. Ultrasound guidance may be necessary to ensure accurate placement into all parts of infraspinatus.

The endoscopic endonasal approach has recently been added to the surgical armamentarium to access the anterior craniovertebral junction (CVJ). Comparative analyses with the transoral approach are scarce. The aim of this study was to provide a quantitative anatomical analysis of both approaches.In four specimens the endoscopic endonasal approach (before and after sphenoidectomy) and the transoral approach (without and with a soft palate split) were performed. ApproachViewer-part of GTx-UHN (Guided Therapeutics software, developed at University Health Network, Toronto, ON, Canada)-was used to quantify and visualize the working volume, as well as the exposed area, of each surgical approach. Different modalities (crossing and non-crossing) were used to quantify the exposure of the deep surface, providing an indirect quantitative value of the 'surgical freedom'. The lowest point exposed by the endonasal approaches was compared with that predicted by preoperative radiological lines. Non-parametric Welch analysis of variance (ANOVA) was used for statistical analyses.The working volume was significantly larger and the distance to the target was shorter with the transoral approaches than with the endonasal approaches. Clival exposure was better with the endonasal approaches than with the non-crossing transoral approach without a soft palate split; areas below C1 were better exposed with the transoral routes. The nasoaxial line best predicted surgical exposure with the endonasal approaches.Endoscopic endonasal and transoral approaches to the anterior CVJ provide optimal exposure of different areas that overlap at the level of C1 when no anatomical anomalies are present. A split of the soft palate is not necessary during the transoral approach if it is combined with an endoscopic endonasal approach.

Background: The endoscopic endonasal approach has recently been added to the surgical armamentarium to access the anterior craniovertebral junction (CVJ). Comparative analyses with the transoral approach are scarce. The aim of this study was to provide a quantitative anatomical analysis of both approaches.

Background and Objectives Adductor canal block contributes to analgesia after total knee arthroplasty. However, controversy exists regarding the target nerves and the ideal site of local anesthetic administration. The aim of this cadaveric study was to identify the trajectory of all nerves that course in the adductor canal from their origin to their termination and describe their relative contributions to the innervation of the knee joint. Methods After research ethics board approval, 20 cadaveric lower limbs were examined using standard dissection technique. Branches of both the femoral and obturator nerves were explored along the adductor canal and all branches followed to their termination. Results Both the saphenous nerve (SN) and the nerve to vastus medialis (NVM) were consistently identified, whereas branches of the anterior obturator nerve were inconsistently present. The NVM contributed significantly to the innervation of the knee capsule, through intramuscular, extramuscular, and deep genicular nerves. The SN had a relatively more modest contribution through superficial infrapatellar and posterior branches as well as contributing to the origin of the deep genicular nerves. Conclusions The results suggest that both the SN and NVM contribute to the innervation of the anteromedial knee joint and are therefore important targets of adductor canal block. Given the site of exit of both nerves in the distal third of the adductor canal, the midportion of the adductor canal is suggested as an optimal site of local anesthetic administration to block both target nerves while minimizing the possibility of proximal spread to the femoral triangle.

Accurate characterization of the craniomaxillofacial (CMF) skeleton using finite element (FE) modeling requires representation of complex geometries, heterogeneous material distributions, and physiological loading. Musculature in CMF FE models are often modeled with simple link elements that do not account for fiber bundles (FBs) and their differential activation. Magnetic resonance (MR) diffusion-tensor imaging (DTI) enables reconstruction of the three-dimensional (3D) FB arrangement within a muscle. However, 3D quantitative validation of DTI-generated FBs is limited. This study compares 3D FB arrangement in terms of pennation angle (PA) and fiber bundle length (FBL) generated through DTI in a human masseter to manual digitization. CT, MR-proton density, and MR-DTI images were acquired from a single cadaveric specimen. Bone and masseter surfaces were reconstructed from CT and MR-proton density images, respectively. PA and FBL were estimated from FBs reconstructed from MR-DTI images using a streamline tracking (STT) algorithm (n = 193) and FBs identified through manual digitization (n = 181) and compared using the Mann–Whitney test. DTI-derived PAs did not differ from the digitized data (p = 0.411), suggesting that MR-DTI can be used to simulate FB orientation and the directionality of transmitted forces. Conversely, a significant difference was observed in FBL (p

Purpose: Altered three-dimensional (3D) joint kinematics can contribute to shoulder pathology, including post-stroke shoulder pain. Reliable assessment methods enable comparative studies between asymptomatic shoulders of healthy subjects and painful shoulders of post-stroke subjects, and could inform treatment planning for post-stroke shoulder pain. The study purpose was to establish intra-rater test-retest reliability and within-subject repeatability of a palpation/digitization protocol, which assesses 3D clavicular/scapular/humeral rotations, in asymptomatic and painful post-stroke shoulders. Methods: Repeated measurements of 3D clavicular/scapular/humeral joint/segment rotations were obtained using palpation/digitization in 32 asymptomatic and six painful post-stroke shoulders during four reaching postures (rest/flexion/abduction/external rotation). Intra-class correlation coefficients (ICCs), standard error of the measurement and 95% confidence intervals were calculated. Results: All ICC values indicated high to very high test-retest reliability (≥0.70), with lower reliability for scapular anterior/posterior tilt during external rotation in asymptomatic subjects, and scapular medial/lateral rotation, humeral horizontal abduction/adduction and axial rotation during abduction in post-stroke subjects. All standard error of measurement values demonstrated within-subject repeatability error ≤5° for all clavicular/scapular/humeral joint/segment rotations (asymptomatic ≤3.75°; post-stroke ≤5.0°), except for humeral axial rotation (asymptomatic ≤5°; post-stroke ≤15°). Conclusions: This noninvasive, clinically feasible palpation/digitization protocol was reliable and repeatable in asymptomatic shoulders, and in a smaller sample of painful post-stroke shoulders. Implications for Rehabilitation In the clinical setting, a reliable and repeatable noninvasive method for assessment of three-dimensional (3D) clavicular/scapular/humeral joint orientation and range of motion (ROM) is currently required. The established reliability and repeatability of this proposed palpation/digitization protocol will enable comparative 3D ROM studies between asymptomatic and post-stroke shoulders, which will further inform treatment planning. Intra-rater test-retest repeatability, which is measured by the standard error of the measure, indicates the range of error associated with a single test measure. Therefore, clinicians can use the standard error of the measure to determine the "true" differences between pre-treatment and post-treatment test scores.

Background Current sacroiliac joint (SIJ) cooled radiofrequency (RF) is based on fluoroscopic anatomy of lateral branches (LBs) in three specimens. Recent studies confirm significant variation in LB positions. Objectives To determine if common fluoroscopic needle placements for cooled SIJ RF are adequate to lesion all S1-3 LBs. If not, would different targets improve lesion accuracy? Methods The LBs of 20 cadavers were dissected bilaterally (40 SIJs), and 26 G radiopaque wires were sutured to the LBs. With a 10-mm radius ruler centered at each foramen, standard targets were assessed, as judged by a clockface on the right, for S1 and S2 at 2:30, 4:00, and 5:30 positions and at S3 at 2:30 and 4:00. Mirror image targets were assessed on the left. Assuming an 8-mm lesion diameter, the percentage of LBs that would not be ablated for each level was determined. Imaging through the superior end plate of S1 was compared against segment specific (SS) imaging. Results Nine point four percent of LBs would not be ablated at S1 vs 0.99% at S2 vs 35% at S3, and 60% of the 40 SIJs would be completely denervated using current targets. SS imaging did not improve results. Alternate target locations could improve the miss rate to 2.8% at S1 and 0% at S3 and would ablate all LBs in 95% of SIJs. Conclusions Using a conservative 8-mm lesion measurement, contemporary cooled RF needle targets are inadequate to lesion all target LBs. Modifications to current targets are recommended to increase the effectiveness of the procedure.

© 2015 Hanley & Belfus. In this manuscript, these authors have utilized years of clinical experience to suggest rehabilitation modifications for Zone III flexor tendon injuries. - Victoria Priganc, PhD, OTR, CHT, CLT, Practice Forum Editor.

Trochanteric bursa (TB) injection with local anesthetic and corticosteroid is a treatment for patients suffering from greater trochanteric pain syndrome. Both landmark (LM)-guided and ultrasound (US)-guided methods have been used, but their accuracies have not been determined. This study examined the accuracy of these injections with cadaveric dissection.Twenty-four hip specimens were randomized to receive TB injections with methylene blue under either LM-guided or US-guided approach. After dissection, the locations of the dye were classified into 3 categories: intrabursal, extrabursal, or combined intrabursal and extrabursal. The presence of dye in the intrabursal space with or without extrabursal leak was considered a successful injection. Accuracy was defined as the percentage of successful injection.The accuracies of the LM-guided and US-guided injection were 0.67 (95% confidence interval 0.35-0.90) and 0.92 (95% confidence interval 0.62-1.00), respectively, with no significant difference.This is the first cadaveric study examining the accuracy of both the US-guided and LM-guided techniques for TB injection. Future clinical studies are required to compare the outcomes of LM-guided and US-guided greater trochanteric pain syndrome injection.

The purpose of this systematic review was to determine the effect of trunk restraint (TR) training on post-stroke compensatory trunk movements during functional reach, and to identify functional gains of TR within the context of the International Classification of Functioning, Disability and Health (ICF).Six databases were searched prior to 20 February 2013. Randomized control trials (RCTs) comparing the effects of a post-stroke reaching intervention with and without TR in the adult post-stroke population were included in this review. Data related to study inclusion/exclusion criteria, methodology, study participants and between-group outcomes (p 0.05) were extracted. All outcomes were categorized according to functional domains defined within the ICF.Five RCTs met the inclusion criteria. TR groups demonstrated significant between-group differences (p 0.05) for decreased compensatory trunk displacement (4/5 RCTs), increased elbow extension (3/5 RCTs) and increased shoulder flexion (2/5 RCTs). All significant between-group differences fell within the Body Structure/Function domain of the ICF.Trunk restraint is a simple, cost-effective technique that may help to reduce compensatory trunk/shoulder/elbow movements in the post-stroke adult population. Synthesis of study outcomes also highlights applications of TR to clinical practice and areas for further research. Implications for Rehabilitation The ability to use the shoulder and elbow to perform functional reach is a primary goal in post-stroke recovery; however, compensatory trunk movements are often used to achieve the reaching goal. Long-term use of compensatory strategies may contribute to secondary impairments, such as learned non-use, joint contractures and pain. Trunk restraint enables functional reach practice, while limiting compensatory strategies in the moderately to severely impaired stroke population.

Background The transverse carpal ligament is an integral factor in the etiology of carpal tunnel syndrome. The purpose of this study was to report the biomechanical properties of this ligament and quantify sex-based differences and regional variation in tissue response. We hypothesized that the mechanical response would not be uniform across the surface, and that female ligament properties would have higher strain profiles and lower mechanical properties. Methods Uniaxial testing of twelve (six males, six females) human fresh frozen cadaveric transverse carpal ligaments was carried out using an Instron Materials Testing Machine. Strain was measured via a non-contact optical method. Findings The following biomechanical properties of the transverse carpal ligament were reported in this work: failure strain (male: 9.2 (SD 5.0), female: 15.5 (SD 7.1)%), strength (male: 4.9 (SD 1.5), female: 4.5 (SD 1.6) MPa), and modulus of elasticity (male: 52.9 (SD 19.6), female: 38.2 (SD 21.9) MPa). The radial side displayed significantly more strain at failure compared to ulnar ( P Interpretation The results of this study provide evidence that manipulative treatments should focus stretching on the radial half of the tissue, which experiences larger strains under uniform loading conditions. In addition, this work suggests possible sex-based differences in mechanical properties of the transverse carpal ligament, which could provide a basis for the development of improved non-surgical treatment methods for carpal tunnel syndrome. The results can also be applied to generate more accurate computational models of the wrist.

Background The goal of this study was to clarify the anatomical origins of the suprascapular and lateral pectoral nerves from the brachial plexus as an aid to surgical exploration. Methods Both nerves were studied in 100 adult cadaver specimens. Topographic points of origin were described as distance from the bifurcation of the upper trunk or distance from the formation point of the lateral cord, using visual anatomical models. Results The suprascapular nerve originated from (1) the posterior division of the upper trunk distal to the bifurcation of the upper trunk (61 specimens); (2) the point of upper trunk bifurcation (29 cases); (3) the upper trunk proximal to the bifurcation point (six cases); and (4) directly from the C5 root (four cases). The lateral pectoral nerve originated from (1) the anterior division of the upper trunk proximal to the point of lateral cord formation (88 cases); (2) the point of lateral cord formation (five cases); (3) the lateral cord distal to the lateral cord formation point (four cases); and (4) the anterior division of the middle trunk (three cases). Eighty-two cases had origins from both the anterior upper trunk and the anterior middle trunk. Conclusions The suprascapular nerve most frequently originates from the posterior division of the upper trunk, and the lateral pectoral nerve from the anterior divisions of the upper and middle trunks. This information can be used to guide the surgeon in identifying the key landmarks of the supraclavicular brachial plexus at surgical exploration.

Background and Objectives Optimization of clinical outcomes of lateral branch radiofrequency ablation or blocks for sacroiliac joint (SIJ) pain requires precise nerve localization; however, there is a lack of comprehensive morphological studies. The objectives of this cadaveric study were to document SIJ innervation relative to bony landmarks in 3 dimensions and to identify reference points visible under ultrasound and fluoroscopy for optimal needle placement. Methods In 25 cadaveric hemipelves, L5-S4 lateral branches were exposed, digitized, and modeled in 3 dimensions. The models were used to compare innervation patterns between specimens and to quantify the distances of the nerves innervating the SIJ relative to the transverse sacral tubercles (TSTs) and posterior sacral foramina. Quadrants of origin of the nerves were recorded. Results The SIJ was innervated by the posterior sacral network: S1-S2 contributed in all specimens, S3 in 88%, L5 in 8%, and S4 in 4%. Most frequently, the lateral branch(es) emerged from the inferolateral S1, superolateral and inferolateral S2, and superolateral S3 quadrants. All TSTs were easily identifiable elevations that were used to landmark the nerves innervating the SIJ. The majority of branches of the posterior sacral network crossed the lateral sacral crest between TST1-3, with the greatest concentration between TST2-3. Only 3 specimens had a branch superior or inferior to these landmarks. Conclusions Based on the innervation pattern and using bony landmarks identifiable under ultrasound and fluoroscopy, 2 radiofrequency ablation techniques were proposed. Further research is required to determine the accuracy and reliability of needle placement and to evaluate clinical outcomes.

Summary Introduction Muscle transfer is used to restore function typically using a single vector of contraction. Although its use with two independently functional muscular units has been employed, in order to refine this concept we endeavoured to detail the intramuscular anatomy of gracilis, a muscle commonly used for transfer. A novel method to capture intramuscular fibre bundle and neurovascular arrangement was used to create a three-dimensional (3D) digital model that allowed for accurate representation of the relationships between all the intramuscular structures to facilitate flap planning. Methods Twenty gracilis muscles were harvested from 15 cadavers. All components of the muscle were digitised using a Microscribe G2 Digitiser. The data were exported to the 3D animation software Autodesk ® Maya ® 2012 whereupon it was rendered into a 3D model that can be exported as static images or videos. Neurovascular anatomy and muscle architecture were analysed from these models, and fibre bundle length, pennation angle and physiological cross-sectional area were calculated from digitised data. Results The muscle is composed of a variable number of distinct longitudinal segments with muscle fibres spiralling onto the tendon. The main artery to the muscle has three main intramuscular patterns of distribution. The venae comitantes drain discrete zones without intramuscular macroscopic anastomoses. The minor pedicles form an anastomotic chain along the anterior border of the muscle and all vessels were biased to the deep surface. The nerve is related to the vessels in a variable manner and both run between longitudinal muscular compartments. Conclusions The digitisation technique may be used to advance knowledge of intramuscular architecture and it demonstrated that the gracilis muscle is comprised of four to seven muscular compartments, each representing a functional unit that may theoretically be differentially activated and could be harnessed for more sophisticated muscle transfers.

Purpose: The temporalis muscle is commonly used for functional transfer. It is architecturally complex, but few studies have examined its intramuscular innervation and none has used 3-dimensional modeling techniques. Understanding neuromuscular compartmentalization may allow the design of local muscle transfers to minimize donor-site morbidity. The purpose of the present study was to document the intramuscular innervation patternsthroughoutthevolumeofthe temporalismuscle and definefunctional units within the muscle. Materials and Methods: In 10 formalin-embalmed cadaveric specimens, the foramen ovale was exposed and the branches of the mandibular nerve were identified. Each branch was digitized in short segments extramuscularly and intramuscularly. Three-dimensional models were reconstructed from the digitized data using Maya software, and the innervation patterns were documented. Results: The temporalis muscle was found to have superior and inferior parts that were further grouped by innervation into regions, with each receiving its innervation from 1 primary nerve. The nerves originated directly from the mandibular nerve, except in 3 specimens, where the posterior deep temporal nerve arose from the masseteric nerve. Conclusion: These results provide a detailed mapping of innervation patterns and suggest there are at least 5 functional compartments. Each of these has the capacity for selective activation, 3 of which have clinical value. These findings may allow for decreased donor-site morbidity and more functionally sophisticated designs in clinical practice. 2013 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 71:1170-1177, 2013

Several studies have shown that cognitive integration of basic and clinical sciences supports diagnostic reasoning in novices; however, there has been limited exploration of the ways in which educators can translate this model of mental activity into sound instructional strategies. The use of self-explanation during learning has the potential to promote and support the development of integrated knowledge by encouraging novices to elaborate on the causal relationship between clinical features and basic science mechanisms. To explore the effect of this strategy, we compared diagnostic efficacy of teaching students (n = 71) the clinical features of four musculoskeletal pathologies using either (1) integrated causal basic science descriptions (BaSci group); (2) integrated causal basic science descriptions combined with self-explanation prompts (SE group); (3) basic science mechanisms segregated from the clinical features (SG group). All participants completed a diagnostic accuracy test immediately after learning and 1-week later. The results showed that the BaSci group performed significantly better compared to the SE (p = 0.019) and SG groups (p = 0.004); however, no difference was observed between the SE and SG groups (p = 0.91). We hypothesize that the structure of the self-explanation task may not have supported the development of a holistic conceptual understanding of each disease. These findings suggest that integration strategies need to be carefully structured and applied in ways that support the holistic story created by integrated basic science instruction in order to foster conceptual coherence and to capitalize on the benefits of cognition integration.

Image-guided sensory block and radiofrequency ablation of the nerves innervating the sacro-iliac joint require readily identifiable bony landmarks for accurate needle/electrode placement. Understanding the relative locations of the transverse sacral tubercles along the lateral sacral crest is important for ultrasound guidance, as they demarcate the position of the posterior sacral network (S1–S3 ± L5/S4) innervating the posterior sacro-iliac joint. No studies were found that investigated the spatial relationships of these bony landmarks. The purpose of this study was to visualize and quantify the interrelationships of the transverse sacral tubercles and posterior sacral foramina to inform image-guided block and radiofrequency ablation of the sacro-iliac joint. The posterior and lateral surfaces of 30 dry sacra (15 M/15 F) were digitized and modeled in 3D and the distances between bony landmarks quantified. The relationships of bony landmarks (S1–S4) were not uniform. The mean intertubercular and interforaminal distances decreased from S1 to S4, whereas the distance from the lateral margin of the posterior sacral foramina to the transverse sacral tubercles increased from S1 to S3. The mean intertubercular distance from S1 to S3 was significantly (p<0.05) larger in males. The interrelationships of the sacral bony landmarks should be taken into consideration when estimating the site and length of an image-guided strip lesion targeting the posterior sacral network.

There is a growing awareness of the need for evidence-based surgery and of the issues that are specific to research in surgery. Well-conducted anatomical studies can represent the first, preclinical step for evidence-based surgical innovation and evaluation. In the last two decades, various reports have quantified and compared neurosurgical approaches in the anatomy laboratory using different methods and technology. The aim of this study was to critically review these papers. A PubMed and Scopus search was performed to select articles that quantified and compared different neurosurgical approaches in the preclinical setting. The basic characteristics that anatomically define a surgical approach were defined. Each study was analyzed for measured features and quantification method and technique. Ninety-nine papers, published from 1990 to 2013, were included in this review. A heterogeneous use of terms to define the features of a surgical approach was evident. Different methods to study these features have been reported; they are generally based on quantification of distances, angles, and areas. Measuring tools have evolved from the simple ruler to frameless stereotactic devices. The reported methods have each specific advantages and limits; a common limitation is the lack of 3D visualization and surgical volume quantification. There is a need for a uniform nomenclature in anatomical studies. Frameless stereotactic devices provide a powerful tool for anatomical studies. Volume quantification and 3D visualization of the surgical approach is not provided with most available methods.

Background The complexity of temporoparietal anatomy is compounded by inconsistent nomenclature. Objective To provide a comprehensive review of the variations in terminology and anatomic descriptions of the temporoparietal soft tissue layers, with the aim of improving learning and communication across surgical disciplines. Methods MEDLINE (1950-2009) searches were conducted for anatomic studies of the temporoparietal region, and for studies describing temporoparietal anatomy in the context of surgical techniques. Results Sixty-nine articles were included in the review. Naming of the soft tissue layers of the temporoparietal region was inconsistent both within and across surgical disciplines, with several terms utilized for the same layer and occasionally the same term applied to different layers. Studies also varied in their description of the vascular, neural, and soft tissue architecture of the temporoparietal region. Conclusion A uniform, descriptive nomenclature is paramount to facilitating surgical education and interpreting future studies. A naming system based on the Terminologica Anatomica is proposed in this review. From superficial to deep, the proposed terms for the soft tissue layers of the temporoparietal region include: temporoparietal fascia, loose areolar tissue plane, superficial leaflet of temporal fascia, fat pad of temporal fascia, deep leaflet of temporal fascia, fat pad deep to temporal fascia, temporalis or temporal muscle, and pericranium.

Background and Objectives Although serratus plane block reportedly provides satisfactory analgesia for breast and thoracic surgeries, the optimal technique for consistent success has not been studied. The goal of this anatomical study was to evaluate the impact of volume, level, and site of injection on the extent of injectate spread that can influence anesthetic coverage. Methods Ultrasound-guided dye injection and subsequent dissection were performed in 39 cadaveric hemithoraces. Methylene blue was injected according to 1 of 4 injection protocols as follows: one 20-mL bolus, either superficial or deep to the serratus anterior muscle (SAM), at the fifth rib level (groups SUP-20 and DEEP-20, respectively), or two 20-mL boluses, either superior or deep to the SAM, one at the third rib and one at the fifth rib level (group SUP-40 and group DEEP-40, respectively). Following injection, dissection and 3-dimensional digitization were performed to map the area of dye spread. Results We found that the extent of dye spread was mostly influenced by the volume of injection rather than the plane of injection (superficial vs deep to SAM). Increasing the volume from 20 to 40 mL doubled the area of injectate spread and promoted dye spread preferentially to the anterior chest wall, with some impact on cephalad-to-caudad spread and no impact on posterior spread. Dye was found most consistently in the axilla when a separate injection was performed at the third rib level. Conclusions Our data showed that a high-volume double-injection technique provides extensive and consistent dye spread in the anterior chest wall and axilla, regardless of the plane of injection relative to the SAM. This technique likely provides more reliable analgesic coverage for breast procedures especially those that involve the axilla, pending confirmation in future clinical studies.

Background Clavicle hook plates are an effective plate fixation alternative for distal clavicle fractures and severe acromioclavicular joint dislocations. However, post-operative complications associated with the subacromial portion of the hook include acromial osteolysis and subacromial impingement. We examine and quantify the three-dimensional position of the subacromial portion of the hook plate relative to surrounding acromial and subacromial structures in a series of cadaveric shoulders to determine if hook positioning predisposes the shoulder to these noted post-operative complications. Materials and methods Fifteen cadaveric shoulders (seven males, eight females) were implanted with 15- or 18-mm hook plates. Dimensions of the acromion and hook plate were digitised and reconstructed into a three-dimensional model to measure acromion dimensions and distances of the subacromial hook relative to surrounding acromial and subacromial structures. Results Inter-specimen dimensions of the acromion were highly variable. Mean acromion width and thickness were greater in males than in females (p = 0.01). The posterior orientation of the subacromial hook varied widely (mean posterior implantation angle = 32.5 ± 20°, range 0–67°). The hook pierced the subacromial bursa in 13/15 specimens, made contact with the belly of the supraspinatus muscle in 9/15 specimens, and had focal contact at the hook tip with the undersurface of the acromion in 9/15 specimens. Conclusions The wide range of acromial dimensions leads to a high degree of variability in the positioning of the subacromial hook. The observed frequency of hook contact with surrounding subacromial structures in a static shoulder confirms that the position of the hook portion of the implant can predispose anatomic structures to the post-operative complications of subacromial impingement and bony erosion.