Cadaveric Limbs Research Articles

Development of an ultrasound-guided proximo-medial approach for injection of the carpal flexor tendon sheath in horses and comparison with the conventional proximo-lateral ´blind` technique.

The aim of this prospective case-control study was to describe and implement a reliable, accurate, and straightforward ultrasound-guided proximo-medial approach technique for injecting the carpal flexor tendon sheath in horses. The proximo-medial ultrasound-guided approach for intrathecal access to the carpal canal, as described in this study, was firstly developed on ten cadaveric limbs using an undiluted ionic iodinated contrast medium. Landmarks were identified, and the access point was established. Subsequently, the technique was validated in ten horses, and its efficacy was compared with the proximo-lateral ´blind` technique. For each injection, the following was recorded: successful injection (contrast within the carpal canal), number of attempts, and whether a structure other than the carpal sheath was penetrated. The ´blind` technique had a total accuracy of 70% (7/10; 95% confidence interval [CI]: CI 35%-93%), with inadvertent injection into the dorso-palmar pouch of the radiocarpal joint, carpal canal surrounding soft tissue, and intravenous injection being the most common issues associated with this approach. In contrast, the ultrasound-guided approach achieved an accuracy of 100% (10/10; 95% confidence interval [CI]: 69%-100%) for intrasynovial administration of the contrast medium. The ultrasound-guided proximo-medial approach for injecting the carpal sheath is an accurate and technically straightforward technique. This approach should be considered for synoviocentesis of the carpal sheath, particularly in horses with no evident effusion.

Anatomical Variations of the Brachial Plexus: A Cadaveric Study

Objective: Variations of the brachial plexus are a lot commoner than presumed and a better understanding of such variations are of crucial importance to achieve successful results in surgical procedures. The aim of our study was to describe the anatomical variations of the brachial plexus in Sri Lankan adult cadavers. Methods: Bilateral upper limbs of cadavers used for routine dissection from January 2023 to September 2024, were examined and the trunks, cords and terminal nerves were described. Images were taken and variations were carefully noted and recorded. Results: Sixty brachial plexuses in 30 cadavers (19 males and 11 females) with a mean age at death of 70.75 years (SD=10.31) were observed. Prevalence of variations was 40%. We report 7 (11.6%) prefixed and 1 postfixed (1.6%) brachial plexuses, variant connections between lateral and medial cords (5 – 8.3%), variant connection between lateral cord and median root of median nerve1(1 - 1.6%), rare variant of only two cords (posterior and combined medial lateral to form an anterior cord), absent musculocutaneous nerve (2 - 2.3%) and musculocutaneous nerve giving a branch to the median nerve (3 – 5%). Conclusion: Variations of the brachial plexus are quite common and highly variable and therefore require constant reporting to provide medical personal with information that could prevent iatrogenic injury and help in proper diagnosis of cases.

Ex-vivo evaluation of a percutaneous thread technique to palmar/plantar annular desmotomy in horses

Palmar/plantar annular desmotomy (PAD) is a surgical procedure to mitigate pain, lameness, and other clinical manifestations of annular ligament syndrome. This study aimed to describe a minimally invasive technique for PAD and evaluate potential damage to adjacent structures in 15 cadaveric limbs from sound horses (forelimb = 6 and hindlimb = 9). A 6 USP polyglycolic acid thread was positioned around the palmar/plantar annular ligament (PAL) on both sides of the limbs through two incisions (proximal and distal to PAL) through the digital sheath and subcutaneous tissue. Kelly forceps, Gerlach or Obwegeser needles were used to thread placement. A back-and-forth motion allowed the thread to cut the ligament until it exited through the proximal skin incision, and the time was registered. The degree of PAL section and tissue injuries were evaluated. The section of the ligament was complete in all limbs. However, 30% (10/30) of the procedures produced iatrogenic injuries on adjacent structures regardless of the instrument used (p > 0.1). There was a higher frequency of lesions in the neurovascular bundle (NVB) on the medial side regardless of the limb (p = 0.068). The odds of injury in the NVB were correlated to side (lateral or medial (p = 0.042) and limb (hind or forelimb) (p = 0.065) by logistic regression. The Gerlach needle had a shorter execution time than the Kelly forceps (p = 0.003). The percutaneous approach to PAD in specimens was practical, quick, and easy to perform. However, this posed a potential chance of iatrogenic trauma to the surrounding tissue. Although they are all reasonable options, the Obwegeser needle was more efficient for applying the thread than the others.

Intraoperative Detection of Screw Penetration Following Volar Plating of the Distal Radius: A Cadaveric Study Comparing Fluoroscopic Imaging and Ultrasound

Abstract Introduction Hardware prominence is one of the major established complications following volar plating of distal radius fractures. The purpose of this cadaveric study is to compare two conventional fluoroscopic imaging views (carpal shoot-through view [CSV] and dorsal horizon view [DHV]) with ultrasound (US) to establish the best intraoperative imaging modality for surgeons to use to identify penetration of screws through the dorsal cortex and/or into the distal radioulnar joint (DRUJ). Materials and Methods Twelve human cadaveric limbs were included in the study, instrumented with distal radius plates via a volar approach. The three imaging modalities, CSV, DHV, and US, were compared in terms of detecting prominent screws during volar plate fixation. Six surgeons with varying levels of expertise performed the evaluations. Sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and the area under the receiver operating characteristic curve were computed for every surgeon and imaging method. Results The CSV was found to be more sensitive compared with the DHV and US for detecting dorsal cortex penetration (99% vs. 94% vs. 56%, respectively). The DHV was found to be more sensitive in recognizing DRUJ screw penetration compared with CSV and US (89% vs. 78% vs. 11%, respectively). US evaluation demonstrated considerably lower diagnostic utility compared with CSV and DHV. Surgeon's ability to perform as well as confidence in evaluating for screw penetration was highest with the CSV view. Conclusion Fluoroscopic imaging, particularly the CSV, demonstrates greater diagnostic reliability compared with US for intraoperative detection of prominent screws following volar plate fixation of the distal radius. CSV was also identified as the most reproducible examination for all levels of expertise with minimal formal training required. Level of Evidence: Therapeutic level V.

A Suture Method for Collateral Ligaments of the Finger Proximal Interphalangeal Joint: A Cadaver Study

In a cadaveric model, a comparison was made of the strength of a suture method for collateral ligaments (the N method) with that of simple sutures using suture anchors for the repair of collateral ligaments in the proximal interphalangeal joint. We obtained 72 fingers from 18 upper limbs of fresh-frozen cadavers and compared the left and right sides of the same specimens. In experiment 1, we examined the rupture strength and rupture sites of intact collateral ligaments in 24 fingers. In experiment 2, we compared the rupture strength and failure modes of the N method (three locking sutures) with those of simple sutures (S group) on 32 fingers. In experiment 3, we examined the rupture strength and failure modes between the N method with three locking sutures (N3 group) and the N method with two locking sutures (N2 group) on 16 fingers. All the experiments involved mechanical testing by applying lateral stress to the collateral ligaments at a rate of 1 mm/s using testing equipment. In Experiment 1, the mean rupture strength of intact collateral ligaments was 80.6 ± 27.5 N. Proximal tears were the most common rupture sites. In Experiment 2, the mean rupture strength was significantly higher in the N group (46.3 ± 19.2 N) than in the S group (24.1 ± 12.7 N). In the N group, suture breakage occurred more frequently than in the S group, whereas in the S group, there was a higher incidence of suture cut out. In Experiment 3, the N3 and N2 groups exhibited nearly identical rupture strength values. This study showed that the N method had better rupture strength than the simple suture method following finger collateral ligament repair. The outcome provides useful information for informing the choice of suture method in clinical practice.

Cadaveric validation of markerless tracking using weightbearing computed tomography versus conventional computed tomography imaging techniques

This study aimed to validate the use of weightbearing computed tomography against conventional computed tomography and against bead tracking for markerless tracking of key foot and ankle bones. A left cadaveric limb was implanted with tantalum beads and underwent conventional computed tomography and weightbearing computed tomography scanning, followed by biplane fluoroscopy motion capture to simulate gait. Bone models from conventional computed tomography and weightbearing computed tomography were compared for surface differences and kinematic analysis across six joints. Results showed the average surface distance difference across all weightbearing computed tomography bones were a fraction of a voxel smaller than the conventional computed tomography bones on average. Additionally, the absolute mean and standard deviation of the mean angle differences across all trials, joints, and planes was less than one degree. Weightbearing computed tomography demonstrated comparable accuracy to conventional computed tomography and to bead tracking, confirming its utility in dynamic biomechanical analysis with reduced radiation exposure and the ability to image under load. This validation supports weightbearing computed tomography's broader adoption in clinical and research settings for enhanced foot and ankle diagnostics and treatment.

Influence of the Vertek aiming device on the surgical accuracy of computer-assisted drilling of the equine distal sesamoid bone-An experimental cadaveric study.

To determine the effect of the Vertek aiming device (VAD) on the surgical accuracy of navigated drilling of the distal sesamoid bone (DSB). Experimental cadaveric study. A total of 30 paired equine cadaveric limbs from 15 horses. Each specimen was placed in a purpose-built frame (PBF). Preoperative cone beam computed tomography (CBCT) images were acquired with an imaging unit coupled with a surgical navigation system. In the DSB of each specimen, a 4.5 mm glide hole and a 3.2 mm thread hole were drilled under navigation guidance, to simulate drilling for the repair of a mid-sagittal DSB fracture. In the VAD group navigated drilling was assisted by using the VAD. In the free-hand drilling group navigated drilling was performed without the VAD. Pre-and postoperative CBCT scans were merged and surgical accuracy aberrations (SAA) between the planned drill corridor and the created bone tunnel were measured. Descriptive statistics and repeated-measures analyses of variance (rep.-meas. ANOVA) were performed to compare SAA measurements between the study groups. The SAA measurements ranged from 0 to 2.9 mm in the free-hand group and from 0 to 2.8 mm in the VAD group. The median overall SAA was lower in the VAD group than in the free-hand navigated group (0.6 mm ± [0.5-0.7] vs. 0.8 mm ± [0.7-1], rep.-meas. ANOVA p = .007). The additional use of the VAD in the described set-up for navigated drilling significantly improved surgical accuracy. The combined use of the VAD and PBF may help improve surgical accuracy in navigated lag screw repair of DSB fractures.

Burr to Bone Time for Joint Preparation in Minimally Invasive Foot and Ankle Fusion Surgeries: A Cadaver Study

Category: Ankle; Midfoot/Forefoot Introduction/Purpose: Minimally invasive surgical (MIS) techniques have been implemented in various foot and ankle procedures, including joint arthrodesis. While these techniques can be effective in reducing complications and improving outcomes, there remains variability with surgeon learning curves, the type of instruments used, and approach to intraoperative imaging. This study seeks to aid surgeons through more reproducible guidelines by measuring the time needed for joint preparation with an MIS specific burr. Methods: A total of 8 cadaveric limbs (4 left and 4 right feet) were used for the preparation of the 1st metatarsophalangeal (MTP), 1st tarsometatarsal (TMT), talonavicular (TN), subtalar and ankle joints. The active burr use time to debride all cartilage from each joint was recorded. Each joint was prepared with an open approach to precisely determine the amount of time needed for cartilage removal. Descriptive statistics and a Kruskal-Wallis with post-hoc comparisons were used to analyze the data. Results: The 1st MTP was prepared with a mean (SD) time of 54.49 (34.65) seconds; the 1st TMT 51.82 (19.69) seconds; the TN joint 87.89 (43.77) seconds; the subtalar joint 59.46 (37.84) seconds; and the ankle joint 95.59 (54.99) seconds. Only the ankle joint preparation times compared with 1st MTP, 1st TMT and subtalar joints were significantly longer. Conclusion: This study provides burr time metrics for joint debridement in MIS foot and ankle arthrodesis procedures. Although there remains variability in types of burrs used, joint sizes and individual experience with the instruments, the timing of joint preparation can be an objective reference for surgeons to effectively and safely perform minimally invasive techniques. Figure 1. Comparison of joint preparation time across different joints The error bars depict one standard deviation of uncertainty. Asterisk (*) lines indicate a statistically significant difference (P < 0.05) based on unadjusted P values from the Dunn post hoc group comparisons. *Abbreviations: metatarsophalangeal (MTP), tarsometatarsal (TMT), talonavicular (TN).

Comparison of Percutaneous Lapidus Intra Osseous Screws vs Open Plate Fixation for First Tarsometatarsal Fusion: A Matched Cadaver Study

Category: Bunion; Midfoot/Forefoot Introduction/Purpose: Foot and ankle joint fusion fixation traditionally uses bridging plates or compression screws. However plates require incisions unsuitable for percutaneous surgery. Therefore in creating a percutaneous Lapidus procedure a new form of fusion fixation was designed. The concept preserves subchondral bone after complete cartilage removal. Fixation is with intra osseus full thread non variable pitch screws. The purpose of this study was to compare the biomechanical properties of the open plate and cross screw construct vs. the percutaneous construct. The cadaveric study goal was to compare the cycles to failure, load to failure and stiffness of each fixation type, and the plantar gap measured during each cycle throughout the test. Loading conditions replicated 6 weeks of walking in a short-leg walking cast. Methods: The TMT joint of six matched cadaveric legs were fixated with a Lapidus procedure: Six limbs with a locking plate and 3.5 mm cross compression lag screw (“plated treatment”) and six with a percutaneous Lapidus procedure, preserving subchondral bone (“MIS treatment”). The three medial metatarsals, cuneiforms, and the navicular were excised from each cadaveric limb and potted, with the TMT joint exposed ~1 cm, then frozen. Specimens were thawed, an extensometer was placed on the plantar side of the TMT, and the 1st metatarsal was loaded 5 cm distal to the TMT joint, from 9N to 90N compression at 3 Hz. Testing was stopped if the extensometer reached 7 mm of plantar gap, or 250,000 cycles were reached. Following fatigue loading, specimens were statically loaded to failure. The maximum load and stiffness were recorded. Bone screw pullout strength and compressive modulus of the distal metatarsal were measured. Results: MIS-treated specimens reached significantly-higher cycles to failure (221,452 cycles) compared to plate-treated specimens (34,941 cycles). Plantar gap was significantly higher at all cycle counts from 10 to 10000 cycles (> 4mm) in the plate-treated group than in the MIS-treated group ( < 1 mm). The maximum load observed in the cantilever static test following fatigue testing was significantly higher in the MIS-treated group (343.3 N) compared to the plate-treated group (247.3 N). The stiffness of the MIS-treated group was also significantly higher than the plate treated group (40.9 N/mm vs 16.0 N/mm). No statistical differences in the screw pullout strength nor compressive modulus were observed. A Cox Proportional Hazard model identified the mode of fixation as the only significant covariant (p=0.03) when predicting cycles-to-failure. Conclusion: Our data indicate the percutaneous Lapidus construct had significantly lower plantar gap during cyclic loading, higher load-to-failure following cyclic loading, higher stiffness, and higher number of cycles required to reach 7 mm of displacement compared to the plate. The implant type (MIS or Plate) was the only covariant which predicted fatigue loading cycles to failure. Stratifying the baseline hazards by implant type in the hazard model, no other covariant reached statistical significance. The percutaneous subchondral fixation fusion construct with full thread non variable pitch intraosseous screws allows stronger fixation than traditional plates and cross screws.

Effect of breed, obturator type and surgical experience on tenoscopic portal creation into the digital flexor tendon sheath in horses.

To determine the influence of breed (cob [CB] and non-cob [NC]), obturator type and surgical experience on the number of attempts, time taken and iatrogenic damage (ID) created when entering the digital flexor tendon sheath (DFTS) tenoscopically. Prospective experimental cadaveric study. A total of 104 cadaver limbs. An equal number of randomly selected CB and NC limbs were operated using a conical obturator (OB) or a switching stick (SS) by one boarded (BS) and one resident surgeon (RS). Skin measurements, number of attempts and time taken to enter the DFTS were recorded. The DFTS was endoscopically examined and then dissected to record ID and cumulative ID calculated. Mean CB skin thickness (8.4 mm) was nearly twice that of NC limbs (4.5 mm) (p < .001). Mean DFTS entry took longer in CB limbs (133 s) compared to NC limbs (112 s) (p = .02). BS mean entry time in CB limbs was 115 s compared to 46 s in NC limbs (p < .001). Cumulative ID was greater in CB limbs (25 of 52 limbs with ID) compared to NC limbs (14 of 52 limbs with ID) (p = .04). No difference was noted between obturators. Surgical experience reduced attempts and time entering the DFTS. Surgeons take longer to enter DFTS in CB limbs and more cumulative ID is created, regardless of obturator type used. Skin thickness is a major determinant of time taken to enter the DFTS and increases the risk of ID. Awareness of the challenges in CB limbs is important.

Use of a new aiming compression device and technique for the repair of navicular bone fractures in horses: A cadaveric study.

To assess the use of a newly developed aiming compression device (ACD) for screw insertion in non-fractured navicular bones (NB) in cadavers. Cadaveric study. A total of 10 cadaveric front limbs of adult horses. Placement of a 3.5 mm cortical screw in non-fractured NB under radiographic guidance was performed in 10 cadaver limbs in a standing position. An ACD was used to stabilize the NB and to guide the drilling process. Preparation and surgical time as well as the number of radiographic images were noted. A postoperative scoring system was used to assess screw placement by cone beam computed tomography (CBCT) and gross examination by two evaluators. The total procedure time was 25-62 min (median 33.5). During the procedure, 11-21 radiographs (median 18.5) were taken. The postoperative gross examination revealed an excellent screw placement in nine NB and poor in one. This could not be reliably assessed with post-procedure CBCT. The described technique achieves an excellent screw placement in 9/10 bones without disrupting the articular or flexural surface of the NB and with no protrusion of the screw head or tip, in a median procedure time of under 35 min. Adequate screw placement is paramount for NB fracture repair. The described approach under radiographic guidance allows adequate screw placement using the ACD to stabilize the NB by lateral to medial compression. This technique facilitates adequate screw placement within the NB without the use of advanced imaging techniques.

Morphology of the lateral circumflex femoral artery in adult cadavers.

The lateral circumflex femoral artery (LCFA) is important for surgical approaches to the hip joint; its branches are often used as grafts and pedicled flaps. Our aim was to contribute to the literature by reporting variations. The LCFA branching pattern was studied in 26 lower limbs of formalin-fixed cadavers. It was recorded whether the LCFA originated from the femoral artery (FA) or the deep femoral artery (DFA). The distances of LCFA from the mid-inguinal point (MIP) and DFA; and the diameters of LCFA and its branches were measured with metric caliper. Side differences were analyzed by Wilcoxon test. The mean shortest distance from the LCFA to the MIP was 59.45 ± 13.06mm and to the DFA was 19.23 ± 9.63mm. The mean diameters of LCFA and its ascending, transverse, and descending branches were 5.82 ± 1.87mm, 3.28 ± 0.87mm, 3.02 ± 0.92mm, and 3.61 ± 0.98mm, respectively. The LCFA originated from 80.8% DFA and 19.2% FA. Data were evaluated jointly (p > 0.05). In one case, an accessory transverse branch was found. Spearman analysis shows that as the distance between the LCFA and the MIP increased, the diameter of the LCFA and its branches increased. Knowledge of the LCFA branching pattern is essential for interventional options in arterial grafts, such as bypass surgery, pedicled flaps, and surgical approaches to the hip joint. Preoperative radiologic evaluation for accurate knowledge of the topography of the branching pattern and vessel size can contribute to successful management of intraoperative blood loss and avoidance of iatrogenic injury.

MRI and Ultrasound Visualization of a Nerve Repair Implant Containing Nitinol.

Nerve Tape is a novel nerve repair device containing nitinol microhooks that provide sutureless attachment for nerve coaptation. This study evaluated visualization of Nerve Tape on magnetic resonance imaging (MRI) and ultrasound, with the objective of exploring its potential as an imaging marker for localizing nerve repair sites. Phantom imaging experiments were first conducted to assess the visibility of Nerve Tape on MRI and ultrasound. A cadaveric limb investigation was then performed to further characterize the magnetic susceptibility patterns of Nerve Tape and to confirm its localization at the repair site. Phantom imaging experiments demonstrated clear visualization of Nerve Tape on both MRI and ultrasound, with Nerve Tape microhooks appearing as signal voids on MRI and hyperechoic foci on ultrasound. Subsequent cadaveric limb investigation further characterized Nerve Tape's magnetic susceptibility patterns and confirmed localization of the device at the repair site. The physical dimensions of Nerve Tape and locations observed on both MRI and ultrasound matched design and measurements made during surgery. Measurement discrepancies could be attributed to magnetic susceptibility artifacts in MRI, and to comet tail and shadowing effects in ultrasound. Repairs performed with Nerve Tape can be reliably localized for imaging, potentially facilitating assessment of repair site integrity and further advancement toward image-based monitoring of nerve regeneration. Further research, including in vivo human studies, is warranted to confirm these preliminary findings.

Predicting Nerve Course Variations to Prevent Iatrogenic Lesions: A Surgical Perspective on Sural Nerve Variations.

There are several documented variations of the sural nerve noted within the literature. This cadaveric study was conducted to provide a surgical perspective to either directly addressing the sural nerve, or avoiding it depending on the injury or pathology being surgically addressed. Twenty-five preserved cadaveric limbs were dissected from the popliteal fossa to the foot. Three locations of the course of the sural nerve data were analyzed. The first location (M1) was from the head of the fibula to the sural nerve. The second location (M3) was from 2.54 cm proximal to the distal tip of the lateral malleolus to the sural nerve. The third location (M2) was from the shaft of the fibula at the halfway point between measurements 1 and 2 to the course of the sural nerve. The types of variations were noted as well, compared to previous studies, highlighting the abundance of sural nerve variations in the lower limb that clinicians and surgeons need to be aware of and ready to address. The sural nerve courses 4.6 cm posterior from the fibula at the proximal fibula and mid fibula and 4.5 cm at the distal fibula. The 25 sural nerve variations are not reflective of what has been previously published in the literature. The data can be utilized in preoperative planning in addressing or avoiding the sural nerve involving the posterior superficial compartment of the leg.

Histological and Histopathological Features of the Third Metacarpal/Tarsal Parasagittal Groove and Proximal Phalanx Sagittal Groove in Thoroughbred Horses with Racing History.

Information regarding the histopathology of the proximal phalanx (P1) sagittal groove in racehorses is limited. Twenty-nine cadaver limbs from nine Thoroughbred racehorses in racing/race-training underwent histological examination. Histological specimens of the third metacarpal/metatarsal (MC3/MT3) parasagittal grooves and P1 sagittal grooves were graded for histopathological findings in hyaline cartilage (HC), calcified cartilage (CC), and subchondral plate and trabecular bone (SCB/TB) regions. Histopathological grades were compared between (1) fissure and non-fissure locations observed in a previous study and (2) dorsal, middle, and palmar/plantar aspects. (1) HC, CC, and SCB/TB grades were more severe in fissure than non-fissure locations in the MC3/MT3 parasagittal groove (p < 0.001). SCB/TB grades were more severe in fissure than non-fissure locations in the P1 sagittal groove (p < 0.001). (2) HC, CC, and SCB/TB grades including SCB collapse were more severe in the palmar/plantar than the middle aspect of the MC3/MT3 parasagittal groove (p < 0.001). SCB/TB grades including SCB collapse were more severe in the dorsal and middle than the palmar/plantar aspect of the P1 sagittal groove (p < 0.001). Histopathology in the SCB/TB region including bone fatigue injury was related to fissure locations, the palmar/plantar MC3/MT3 parasagittal groove, and the dorsal P1 sagittal groove.

Ex vivo diffusion tensor imaging of the plantar nerves is feasible in the horse.

The objective of this study was to optimize an MRI-based diffusion tensor imaging (DTI) protocol for imaging the plantar nerves at the level of the tarsus in normal equine limbs. 12 pelvic cadaver limbs from horses without evidence of proximal suspensory pathology were imaged with a 3T MRI system. For diffusion-weighted imaging, b values of 600, 800, and 1,000 s/mm2 were tested. Data were processed with DSI Studio. Cross-sectional areas of the medial and lateral plantar nerve along the plantar tarsus were recorded. The length and number of fiber tracts, signal-to-noise ratio, and DTI variables were recorded. At the level of interest, the mean cross-sectional areas of the plantar nerves ranged from 5.03 to 7.42 mm2. The DTI maps consistently generated tracts in the region of the lateral and medial plantar nerves with DTI values in the range of values reported for peripheral nerves in humans. Our findings demonstrate that DTI of the medial and lateral plantar nerves can be performed successfully and used to generate quantitative parameters including fractional anisotropy and mean, axial, and radial diffusivity. Quantitative data generated with this imaging technique can be used to noninvasively characterize the microstructural integrity of neural tissue with possible applications in the evaluation of pathologic changes to the plantar tarsal and metatarsal nerves of horses with proximal suspensory desmopathy.

Evaluation of the cutaneous blood supply and vascular territories of the wrist

PurposeTo determine and evaluate the distal forearm and wrist's cutaneous blood supply and vascular territories. MethodsFour cadaveric upper extremities were injected with a radiopaque, lead-based contrast agent through the brachial artery. After the lead-based contrast agent set, the cadaveric limbs underwent computed tomographic (CT) scanning to assess the perforators to the cutaneous skin of the distal forearm and wrist. High-resolution axial CT and three-dimensional reconstructions were generated to highlight perforating vessels stemming from their parent arteries. Subsequently, anatomic microdissections were performed to identify and trace the perforating vessels identified on CT. ResultsCT analysis and anatomic microdissection demonstrated that the dorsal surface of the distal forearm and wrist are supplied by numerous perforators stemming predominantly from the anterior interosseous artery with some anastomotic contribution from the posterior interosseous, radial, and ulnar arteries. Perforators from the radial and ulnar arteries supply the volar surface. There are large anastomotic networks formed between the perforating vessels. ConclusionsThe distal forearm and wrist have a robust anastomotic blood supply that has contributions from the anterior interosseous, posterior interosseous, radial, and ulnar arteries. Clinical relevanceThe extensive perforator-derived blood supply to the skin likely accounts for the excellent soft tissue healing potential of the wrist following surgery utilizing multiple incisions.

Investigation of subtle Lisfranc injuries using weight-bearing computed tomography

Introduction: Lisfranc ligamentous injuries are common yet remain a diagnostic challenge. Automated analysis of weight-bearingcomputed tomography (WBCT) images has been investigated to diagnose various pathologies. However, it has not been studied forLisfranc ligament injuries. The objective of the study was to examine whether automated WBCT analysis could demonstrate diagnosticutility for these injuries. Methods: Serial sectioning of Lisfranc complex ligaments was conducted on 24 cadaveric limbs to simulate Lisfranc injuries. WBCT images were collected at each dissection condition under three loading conditions. Images were automatically segmented, and automated measures of specific angles and distances in the midfoot were calculated using digitally reconstructed radiographs. These were analyzed using repeated measures ANOVA and paired T-tests to identify significant differences between dissections at each loading condition. Results: Overall, minimal differences between dissection conditions were observed in automatically generated measures. Differences in axial angles of the metatarsals in severe dissections were observed, and there were fewer differences in angular measures across dissection conditions in fully loaded than unloaded conditions. Conclusions: Automated analysis of WBCT images may indicate severe Lisfranc ligamentous injury but is insufficient to diagnose ligament injuries without full capsule disruption. This lack of injury markers may be due to the imaging conditions, automated analysis, or biomechanics of Lisfranc injuries. More alignment differences were seen under unloaded conditions, suggesting that weight-bearing imaging may not be appropriate for this injury. Overall, automated analysis shows only minimal changes in alignment measures, and additional study is necessary to improve diagnostic tools for Lisfranc injuries. Evidence Level V; Mechanism-based reasoning.

The construction of canine distal limb models used in teaching sonography identification of vegetal foreign bodies.

Musculoskeletal ultrasonography is a useful tool to identify radiolucent vegetal foreign bodies (VFBs). However, limited ultrasound experience and unfamiliarity with the normal sonographic appearance of anatomical structures can decrease clinician confidence. This study aimed to design a reusable silicone model that can teach VFB identification within the canine distal limb. Four canine hindlimbs were used to design the silicone models, and 12 canine distal forelimbs were constructed. The model was constructed using cadaver bones, barley grass (Avena fatua) seeds, and silicone to mimic the anatomy of the canine distal limb with a grass seed VFB. Limbs were randomly grouped based on grass seed locations: (1) the interdigital webbing, (2) the palmar surface of the canine forelimb immediately proximal to the metacarpal pad, (3) the dorsal surface of the distal limb immediately proximal to the proximal phalange, or (4) no grass seed (control) placed. Each limb was systematically ultrasounded and compared with cadaver limbs and clinical VFB cases. A comparison of ultrasonographic images validated the construction, revealing that the simulation model replicates the anatomical and echotexture characteristics of the normal canine distal limb. Furthermore, these models also have a likeness to clinical canine distal limb VFB cases and can be utilized as a training tool.

Quantifying Bone and Skin Movement in the Residual Limb-Socket Interface of Individuals With Transtibial Limb Loss Using Dynamic Stereo X-Ray: Protocol for a Lower Limb Loss Cadaver and Clinical Study.

Relative motion between the residual limb and socket in individuals with transtibial limb loss can lead to substantial consequences that limit mobility. Although assessments of the relative motion between the residual limb and socket have been performed, there remains a substantial gap in understanding the complex mechanics of the residual limb-socket interface during dynamic activities that limits the ability to improve socket design. However, dynamic stereo x-ray (DSX) is an advanced imaging technology that can quantify 3D bone movement and skin deformation inside a socket during dynamic activities. This study aims to develop analytical tools using DSX to quantify the dynamic, in vivo kinematics between the residual limb and socket and the mechanism of residual tissue deformation. A lower limb cadaver study will first be performed to optimize the placement of an array of radiopaque beads and markers on the socket, liner, and skin to simultaneously assess dynamic tibial movement and residual tissue and liner deformation. Five cadaver limbs will be used in an iterative process to develop an optimal marker setup. Stance phase gait will be simulated during each session to induce bone movement and skin and liner deformation. The number, shape, size, and placement of each marker will be evaluated after each session to refine the marker set. Once an optimal marker setup is identified, 21 participants with transtibial limb loss will be fitted with a socket capable of being suspended via both elevated vacuum and traditional suction. Participants will undergo a 4-week acclimation period and then be tested in the DSX system to track tibial, skin, and liner motion under both suspension techniques during 3 activities: treadmill walking at a self-selected speed, at a walking speed 10% faster, and during a step-down movement. The performance of the 2 suspension techniques will be evaluated by quantifying the 3D bone movement of the residual tibia with respect to the socket and quantifying liner and skin deformation at the socket-residuum interface. This study was funded in October 2021. Cadaver testing began in January 2023. Enrollment began in February 2024. Data collection is expected to conclude in December 2025. The initial dissemination of results is expected in November 2026. The successful completion of this study will help develop analytical methods for the accurate assessment of residual limb-socket motion. The results will significantly advance the understanding of the complex biomechanical interactions between the residual limb and the socket, which can aid in evidence-based clinical practice and socket prescription guidelines. This critical foundational information can aid in the development of future socket technology that has the potential to reduce secondary comorbidities that result from complications of poor prosthesis load transmission. DERR1-10.2196/57329.