Recommended recumbency to avoid insertional complications during small-bore wire-guided thoracostomy tube placement in cats-a cadaver study.

BACKGROUND: Small-bore wire-guided thoracostomy tubes (SBWGTT) are commonly used in cats to manage pleural disease and generally have a low complication rate. Our study aimed to explore the correlation between recumbency of cats, placement method, and the occurrence of insertional complications to identify risk factors during SBWGTT placement. In this experimental cadaveric study, SBWGTT placement using a modified Seldinger technique was conducted in 24 feline cadavers. Cats, euthanized for reasons unrelated to the study, were randomly assigned to pleural effusion (EFF; n = 12) and pneumothorax (PNEU; n = 12) groups. Each cadaver was intubated and ventilated with a peak inspiratory pressure (PIP) of 10 mmHg, and sterile saline or air was instilled into the thorax over a 5 mm thoracoscopic trocar in the fourth intercostal space (ICS). Instillation was stopped when the lateral thoracic wall to lung distance (TWLD) reached 10 to 12 mm, measured with ultrasound in the favorable position. Sternal recumbency was the favorable position for the EFF group, and lateral recumbency for the PNEU group. Following the placement of the first SBWGTT in each group, the cadavers were positioned unfavorably (lateral recumbency for EFF group, sternal recumbency for PNEU group), and a second drain was introduced contralaterally. A bilateral 8th ICS thoracotomy was then performed to visually assess intrathoracic structures and drain integrity. A binary logistic regression mixed model was conducted to determine interaction between the induced condition and body position. RESULTS: A total of 48 SBWGTTs were placed, with complications observed in 33.3% (8/24) of cases. Five of these were major complications consisting of lung lacerations. Complications were more common in the unfavorable position, accounting for 75% of cases, although this result was not statistically significant. The odds of complication rates were > 70% in the unfavorable position and decreased with an increase in TWLD (< 30%). CONCLUSION: Complications associated with SBWGTT placement are influenced by recumbency, although the data did not reach statistical significance. Placing cats in lateral recumbency for pneumothorax treatment and sternal recumbency for pleural effusion treatment may reduce insertional complications.

A "Window" to Protect the Facial Nerve: A Descriptive Cadaveric Study.

Introduction: Success in skeletal surgery depends on adequate access and exposure of the underlying skeletal structures. The retromandibular approach exposes the ramus condyle region through the posterior border of the mandible by utilizing the space between marginal mandibular and buccal branches of the facial nerve. Length of this safety window and accessibility varies in each individual owing to the differing ramifications of peripheral branches of facial nerve. These variations cannot be adequately assessed through clinical studies. Cadaveric studies permit us to extensively explore the surgical area to demystify the branching pattern and its relationship to the adjacent structures. Method: Thirty well-preserved cadaveric facial halves were dissected using a retromandibular incision. Visibility and accessibility were objectively graded through a scale. The safety window and furcation distance were measured using caliper and scale. The appearance of the retromandibular vein was also noted. Results: Eighteen facial halves showed maximum accessibility wherein the surgeon is expected to visualize the condylar neck, subcondylar region and posterior half of ramus. In 8 facial halves, accessibility was limited to subcondylar and midportion of posterior ramus, and in 8 facial halves, accessibility was limited to the midportion of ramus of the mandible. Safety window ranged from 1.9 to 3.5 cms. Distance between the posterior border of mandible and bifurcation of the facial nerve ranged from 0.5 to 1.5 cms. Facial nerve was encountered in 24 facial halves during the retromandibular approach. Retromandibular vein was encountered in 23 facial halves during the retromandibular approach. Discussion: The retromandibular approach is a versatile approach to the condyle subcondylar area as it provides much-required visibility and accessibility. The facial nerve branching pattern and intercommunicating branches determine the safety window which is adequate in most cases. The retromandibular vein is a reliable landmark predicting the vicinity of the facial nerve.

Intraoperative Real-Time Image-Guided Fibular Harvest and Mandibular Reconstruction: A Feasibility Study on Cadaveric Specimens.

BACKGROUND: This study assesses the feasibility of real-time surgical navigation to plan and guide sequential steps during mandible reconstruction on a series of cadaveric specimens. METHODS: An image-guided surgical (IGS) system was designed including customized mandible and fibula fixation devices with navigation reference frames and an accompanied image-guided software. The mandibular and fibular segmental osteotomies were performed using the IGS in all five cadaveric patients. Procedural time and cephalometric measurements were recorded. RESULTS: Five real-time IGS mandibulectomy and fibular reconstruction were successfully performed. The mean Dice score and Hausdorff-95 distance between the planned and actual mandible reconstructions was 0.8 ± 0.08 and 7.29 ± 4.81 mm, respectively. Intercoronoid width, interangle width, and mandible projection differences were 1.15 ± 1.17 mm, 0.9 ± 0.56 mm, and 1.47 ± 1.62 mm, respectively. CONCLUSION: This study presents the first demonstration of a comprehensive image-guided workflow for mandibulectomy and fibular flap reconstruction on cadaveric specimens and resulted in adequate cephalometric accuracy.

A Cadaveric Study of the Rotator Cable: Interrogating the Suspension Bridge Model.

Purpose The objective of this cadaveric study was to describe the anatomical relationships between the rotator cuff muscles and the rotator cable. Methods In 30 formaldehyde-fixed shoulders from 20 cadavers, the rotator cuff and rotator cable were dissected and the glenohumeral joint opened. The orientation and attachments of the rotator cable to the rotator cuff muscles were described, and the severity of any osteoarthritis, labral pathology, and rotator cuff pathology present was documented. The width and thickness of the infraspinatus attachments to the rotator cable were measured. Results The infraspinatus muscle was noted to be more loosely adherent to the rotator cable, while the supraspinatus and teres minor were tightly adherent to the cable. Specifically, the superior-most portion of the infraspinatus was found to be less tightly adherent than the inferior-most portion in 26 of the 30 shoulders studied. The thickness/width ratio of the inferior-most portion of infraspinatus was significantly different in shoulders with more-than-minimal osteoarthritis and labral pathology (p=0.048 and p=0.041, respectively). Conclusion While the supraspinatus and teres minor muscles were tightly adherent to the cable in all shoulders, the degree of attachment of the superior-most portion of the infraspinatus muscle was notably less in 26 of the 30 shoulders studied. This could mean that only the inferior portion of the infraspinatus participates in stress shielding through the cable or be a compensatory response to increased load on the tendon. This work is expected to provide insight into the function of the rotator cable and the different functions of the infraspinatus.

Shoulder Traction as a Possible Risk Factor for C5 Palsy in Anterior Cervical Surgery: A Cadaveric Study.

Background and Objectives: Many risk factors for postoperative C5 palsy (PC5P) have been reported regarding a "cord shift" after a posterior approach. However, there are few reports about shoulder traction as a possible risk factor of anterior cervical surgery. Therefore, we assessed the stretched nerve roots when shoulder traction was applied on cadavers. Materials and Methods: Eight cadavers were employed in this study, available based on age and the presence of foramen stenosis. After dissecting the sternocleidomastoid muscle of the cadaver, the shoulder joint was pulled with a force of 2, 5, 8, 10, 15, and 20 kg. Then, the stretched length of the fifth nerve root was measured in the extra-foraminal zone. In addition, the same measurement was performed after cutting the carotid artery to accurately identify the nerve root's origin. After an additional dissection was performed so that the superior trunk of the brachial plexus could be seen, the stretched length of the fifth and sixth nerve roots was measured again. Results: Throughout the entire experiment, the fifth nerve root stretched out for an average of 1.94 mm at 8 kg and an average of 5.03 mm at a maximum force of 20 kg. In three experiments, the elongated lengths of the C5 nerve root at 8 kg and 20 kg were 1.69/4.38 mm, 2.13/5.00 mm, and 0.75/5.31 mm, respectively, and in the third experiment, the elongated length of the C6 nerve root was 1.88/5.44 mm. Conclusions: Although this was a cadaveric experiment, it suggests that shoulder traction could be the risk factors for PC5P after anterior cervical surgery. In addition, for patients with foraminal stenosis and central stenosis, the risk would be higher. Therefore, the surgeon should be aware of this, and the patient would need sufficient explanation.

Vascularized hemi-hamate graft: Anatomic description of a novel pedicled osteo-chondro-ligamentous flap for proximal scaphoid reconstruction.

Scaphoid proximal pole destruction remains a surgical challenge owing to its high propensity for nonunion and osteonecrosis. The hemi-hamate graft has shown promising results in addressing this issue. However, long-term results of non-vascularized composite grafts remain uncertain. The purpose of this study was to investigate the feasibility of a vascularized hemi-hamate osteo-chondro-ligamentous pedicled flap for the reconstruction of the proximal pole of the scaphoid. Thirty fresh cadaveric wrists were used to harvest the hamate proximal pole on the dorsal intercarpal arch. A loss of substance of the scaphoid proximal pole was simulated and the hamate flap was transferred. In 15 wrists, a canulated screw osteosynthesis was performed to assess donor site morbidity and carpus stability on post-osteosynthesis dynamic radiographs. This study suggests that the proximal hamate can be harvested pedicled on the dorsal intercarpal arch. The pedicle (average pedicle diameter 0.9 mm, mean length 31.5 mm) allowed tension-free graft placement in all dissections, except for one. The morphology of the graft was very similar to that of the scaphoid proximal pole and the palmar capito-hamate ligament allowed scapholunate ligament reconstruction in all dissections. This is the first study that describes the use of a pedicled flap to fully reconstruct the complex osteo-chondro-ligamentous anatomy of the scaphoid proximal pole. This vascularized hemi-hamate flap could facilitate better long-term preservation of cartilage biomechanical properties compared to non-vascularized grafts. Donor site morbidity requires further investigation before recommending clinical use.

The Recommended Deltoid Intramuscular Injection Sites in the Adult Population: A Cadaveric Pilot Study With an Orthopedic Perspective.

Background and aim The deltoid is a common site for intramuscular injections, but guidelines for administration lack standardization. Global researchers propose various techniques, and recent study reports indicate a 1.5-15% incidence of nerve palsies due to injections. This pilot cadaveric study aimed to standardize the deltoid intramuscular injection sites in the Southeast Asian population. Methods This cadaveric study of a two-year duration was conducted in the Department of Anatomy as an intramural research project in collaboration with the Departments of Anatomy and Orthopedics. In the first year of study, which was the pilot phase of the project, the available six cadavers, i.e., 12 upper extremity specimens were dissected. Anthropometric measurements of deltoid muscle along with the distance of underlying neurovascular structures like the axillary nerve and posterior circumflex humeral artery were measured from neighboring bony landmarks. This article presents the observations of the six cadavers studied in the pilot phase and shall be followed up by another article after the project. Results In adults, in anatomical position, the mean distances of the axillary nerve and posterior circumflex humeral artery from the mid-acromial point are 8.19±0.616 and 8.66±0.968 cm, respectively. The deltoid thickness at 3, 5, and 7 cm from mid-acromial point was observed to be 1.079±0.13 cm (0.5-1.78 cm), 1.599±0.12 cm (1-2.96 cm), and 1.815±1.0 cm (1.2-2.5 cm), respectively. The acquired qualitative and quantitative data were tabulated, graphically represented, and statistically analyzed. Conclusions The deltoid intramuscular injection (IMI) must be given at or below the level of the midpoint of the deltoid muscle, but never in the upper half. We recommend a site, 4 fingerbreadths/9 cm below the mid-acromion point as the safest site to avoid injury to any underlying neurovascular structures.

The use of fully threaded headless cannulated screws for femoral neck fracture fixation in small-breed dogs show promise in cadaveric study.

OBJECTIVE: To biomechanically evaluate the stability of internal fixation methods for femoral neck fractures in small-breed dogs. Furthermore, the possibility of replacing the headed screw with fully threaded headless cannulated screws in the fixation method was assessed. METHODS: The study was conducted from December 12, 2023, to February 7, 2024. A total of 18 femurs from 9 canine cadavers were used in this study. After a simple neck fracture was created, in group A (n = 6), the fracture was stabilized with three 1.1-mm parallel Kirschner wires (K-wires). In group B (n = 6), a 3.0-mm partially threaded cannulated screw and an antirotation pin were used. In group C (n = 6), a 2.5-mm fully threaded headless cannulated screw and an antirotation pin were used. A mechanical test was conducted to apply a single axial compressive load to the femoral head. RESULTS: 9 adult small-breed dogs weighing 3.6 to 8.3 kg (mean ± SD; 5.9 ± 1.6). The mean maximum failure load was highest in group C (495 ± 81 N), followed by group B (454 ± 50.4 N), and then group A (222 ± 21.6 N). Significant differences in maximum failure load were observed between groups A and B as well as groups A and C but not between groups B and C. CONCLUSION: The use of fully threaded headless cannulated screws presents a promising method for internal fixation of canine femoral neck fractures. CLINICAL RELEVANCE: To demonstrate the potential stability and reliability of fully threaded headless cannulated screws.

Percutaneous Surgery for Trigger Finger Treatment Using a Novel Surgical Device: An Experimental Study on Fresh Cadavers.

Purpose: Trigger finger, a stenosing tenosynovitis of the flexor tendon at the A1 pulley, can cause pain and impair daily activities. Despite common surgical interventions, postsurgical complications are frequent, prompting the search for less invasive techniques. Methods: An experimental study was conducted on fresh cadavers to compare three techniques: the first using a PulleyCut without ultrasound guidance, the second using a PulleyCut with ultrasound guidance, and the third using a percutaneous needle technique. The complete release of the A1 pulley, integrity of the A2 pulley, flexor tendons, and neurovascular bundles were assessed. Results: The new device group and the ultrasound-guided group demonstrated 100% complete release of the A1 pulley, whereas the needle group achieved only 38% success. There were no A2 pulley injuries in any group. Flexor tendons were injured in 7% of cases in the new device group and 77% in the needle group. A neurovascular injury occurred in the needle group. Conclusions: Compared with the percutaneous needle technique, the new device proved safe and effective for A1 pulley release, minimizing damage to flexor tendons and neurovascular structures. Ultrasound did not provide significant advantages, suggesting that the new device can be confidently used without ultrasound assistance. The PulleyCut represents a promising percutaneous technique for trigger finger treatment, demonstrating superiority over the needle technique in terms of efficacy and safety. These results encourage future clinical investigations to validate its practical application. Type of study/level of evidence: Therapeutic IIc.

Endoscopy-assisted high cervical anterolateral retropharyngeal approach to clivus: a cadaveric study.

Introduction: The surgical management of pathologies involving the clivus and craniocervical junction has always been considered a complex procedure because of the deeply located surgical targets and the surrounding complex neural and vascular anatomical structures. The most commonly used approaches to reach this area are the transnasal, transoral, and transcervical approaches. Material and Methods: This approach was performed unilaterally on five cadaver heads and bilaterally on one cadaver head. Results: We described a modified endoscope-assisted high cervical anterolateral retropharyngeal approach in which each stage of the procedure was demonstrated on human cadavers in a step-by-step manner using endoscopic camera views. This approach was broken down into nine steps. The neurovascular structures encountered at each step and their relationships with each other are demonstrated. Discussion: The advantages and disadvantages of our modified approach were compared to the conventional transcervical, transoral, and endoscopic endonasal approaches.

Risk of Axillary Nerve Injury With Medial Support Screws in Intramedullary Nails: An Anatomical Study.

BACKGROUND: In recent years, intramedullary nails with medial support screws for proximal humeral fractures have become available. Although these devices have a potential risk of iatrogenic axillary nerve injury, no studies have investigated the anatomical relationship between the medial support screws in the modern intramedullary nail and the axillary nerve. This study aimed to clarify the anatomical relationship between the medial support screws in the intramedullary nail and the axillary nerve. MATERIALS AND METHODS: In total, 29 cadaveric shoulders (mean age: 82.6 years old (range: 61-105); 15 males and 14 females) were included in this study. Shoulders within whole-body cadavers were used in all cases. A single proximal humeral nail with medial support screws (ARISTO Proximal Humeral Nail; MDM, Tokyo, Japan) was used. The distance of each medial support screw from the axillary nerve and its branches was measured. RESULTS: In two (6.90%) of 29 shoulders, the axillary nerves came into contact with the medial support screws. In the remaining 27 of 29 shoulders (93.1%), the nerves were located proximal to the medial support screws. CONCLUSION: Medial support screws in proximal humeral fracture nails had the potential to injure the axillary nerve and its branches.

Endoscopic-assisted transorbital extended orbital exenteration: A multi-institutional preclinical study.

BACKGROUND: Sinonasal malignancies with orbital invasion have dismal prognosis even when treated with orbital exenteration (OE). Sugawara et al. developed a surgical strategy called "extended-OE (EOE)," showing encouraging outcomes. We hypothesized that a similar resection is achievable under endoscopic guidance through the exenterated orbit (endoscopic-EOE). METHODS: The study was conducted in three institutions: University of Vienna; Mayo Clinic; University of Insubria; 48 orbital dissections were performed. A questionnaire was developed to evaluate feasibility and safety of each step, scoring from 1 to 10, ("impossible" to "easy," and "high risk" to "low risk," respectively), most likely complication(s) were hypothesized. RESULTS: The step-by-step technique is thoroughly described. The questionnaire was answered by 25 anterior skull base surgeons from six countries. Mean, median, range, and interquartile range of both feasibility and safety scores are reported. CONCLUSIONS: Endoscopic-EOE is a challenging but feasible procedure. Clinical validation is required to assess real-life outcomes.

Radial and median nerves distal peripheral tension after reverse shoulder arthroplasty: a cadaveric study.

Background: Peripheral nerve injury is a recognized complication after reverse shoulder arthroplasty (RSA) that has mainly been studied at the level of the brachial plexus and its proximal branches. However, the impact of RSA on distal peripheral nerves and the influence of elbow and wrist position is not known. This cadaveric study aimed to analyze the effect of RSA implantation and upper limb position on tension in the distal median and radial nerves. The hypothesis was that RSA increased distal nerve tension, which could be further affected by elbow and wrist position. Methods: 12 upper limbs in 9 full fresh-frozen cadavers were dissected. Nerve tension was measured in the median nerve at the level of the proximal arm, elbow, and distal forearm, and in the radial nerve at the level of the elbow, using a customized three-point tensiometer. Measurements were carried out before and after RSA implantation, using a semi-inlay implant (Medacta, Castel San Pietro, Switzerland). Two different configurations were tested, using the smallest and largest available implant sizes. Three upper-limb key positions were considered (plexus at risk, plexus relief, and neutral), from which the effect of elbow and wrist position was further tested. Results: RSA implantation significantly increased median and radial nerve tension throughout the upper limb. The distal nerve segments were particularly dependent on elbow and wrist position. The plexus at risk position induced the most tension in all nerve segments, especially with the large implant configuration. On the other hand, the plexus relief position induced the least amount of tension. Flexing the elbow was the most efficient way to decrease nerve tension in all tested nerve segments and key positions. Wrist flexion significantly decreased nerve tension in the median nerve, whereas wrist extension decreased tension in the radial nerve. Conclusion: RSA significantly increases tension in the median and radial nerves and makes them more susceptible to wrist and elbow positioning. The mechanism behind distal peripheral neuropathy after RSA may thus result from increased compression of tensioned nerves against anatomical fulcrums rather than nerve elongation alone. Elbow flexion was the most effective way to decrease nerve tension, while elbow extension should be avoided when implanting the humeral component. Further studies are needed to assess the ulnar nerve.

A New Methodology for the Accurate Measurement of Tibiofemoral Kinematics in Human Cadaveric Knees: An Evaluation of the Anterior-Posterior Laxity Pre- and Post-Cruciate Ligament Resection.

Anterior-posterior (AP) stability is an important measure of knee performance after total knee arthroplasty (TKA). To improve the stabilizing effect of implants designed to compensate for the loss of the cruciate ligaments, it is important to understand the tibiofemoral contact situation within the native ligamentous situation of the knee and how it changes after cruciate ligament resection. This in vitro study introduces a new approach to accurately measure the tibiofemoral kinematics in a six-degrees-of-freedom joint motion simulator by tracking landmark-based coordinate systems and their corresponding bone geometries. The tibiofemoral contact situation was investigated by projecting the medial and lateral flexion facet centers onto the tibial plateau under AP shear forces across various flexion angles in thirteen knees. Tests were conducted pre- and post-cruciate ligament resection. Post-cruciate ligament resection, the femoral condyles shifted closer to or even exceeded the posterior border of the tibial plateau, but only slightly closer to the anterior border. This study presents a new methodology for measuring the tibiofemoral kinematics that can be applied to multiple loading profiles. It provides a basis for further investigations, including passive or active muscle forces, to enhance the design of total knee protheses and improve surgical outcomes.

An ex vivo sequential ligament transection model of flatfoot.

BACKGROUND: The ligaments implicated in the earliest stages of developing a progressive collapsing foot deformity are poorly understood. Commonly employed cadaveric flatfoot models are created from simultaneous transection of multiple ligaments, making it difficult to assess early changes in pressure distribution from ligaments critical for maintaining load distribution. A serial transection of ligaments may provide insight into changes in pressure distribution under the foot to identify a potential combination of ligaments that may be involved in early deformities. METHODS: Specimens were loaded using a custom designed axial and tendon loading system. Plantar pressure data for the forefoot and hindfoot were recorded before and after six sequential ligament complex transections. FINDINGS: Sectioning the plantar fascia (first) and short/long plantar ligaments (second) failed to generate appreciable differences in load distribution. Dividing the spring ligament (third) led to changes in hindfoot load distribution with a shift towards the lateral column indicative of hindfoot valgus angulation. All subsequent conditions resulted in similar patterns in hindfoot plantar load distribution. An anterior shift in the center of pressure only occurred after transection of all six ligament complexes. INTERPRETATION: Loss of the plantar fascia and short/long plantar ligaments are not critical in maintaining plantar load distribution or contact area. However, the additional loss of the spring ligament caused notable changes in hindfoot load distribution, indicating the combination of these three ligament complexes is particularly critical for preventing peritalar subluxation. Minimal changes in load distribution occurred when performing additional transections to reach a complete flatfoot deformity.

Evaluating the accuracy of a new robotically assisted system in cadaveric total knee arthroplasty procedures.

BACKGROUND: Robot-assisted total knee arthroplasty (TKA) has been shown to facilitate high-precision bone resection, which is an important goal in TKA. The aim of this cadaveric study was to analyze the accuracy of the target angle and bone resection thickness of a recently introduced robotic TKA system. METHODS: This study used 4 frozen cadaveric specimens (8 knees), 2 different implant designs, navigation, and a robotic system. The 4 surgeons who participated in this study were trained and familiar with the basic principles and operating procedures of this system. The angle of the bone cuts performed using the robotic system was compared with the target angles from the intraoperative plan. For each bone cut, the resection thickness was recorded and compared with the planned resection thickness. RESULTS: The mean angular difference for all specimens was less than 1°, and the standard deviation was less than 2°. The mean difference between the planned and measured angles was close to 0 and not significantly different from 0 except for the difference in the frontal tibial component angle, which was 0.88°. The mean difference in the hip-knee-ankle axis angle was - 0.21°± 1.06°. The mean bone resection difference for all specimens was less than 1 mm, and the standard deviation was less than 0.5 mm. CONCLUSIONS: The results of the cadaveric experimental study showed that the new TKA system can realize highly accurate bone cuts and achieve planned angles and resection thicknesses. Despite the limitations of small sample sizes and large differences between cadaveric and clinical patients, the accuracy of cadaveric experiments provides strong support for subsequent clinical trials.

Simulated subacromial injection instruction improves accuracy and skill level: a model for musculoskeletal procedural training.

BACKGROUND: Musculoskeletal (MSK) complaints often present initially to primary care physicians; however, physicians may lack appropriate instruction in MSK procedures. Diagnostic and therapeutic injections are useful orthopedic tools, but inaccuracy leads to unnecessary costs and inadequate treatment. The authors hypothesized that trainees afforded the opportunity to practice on a cadaver versus those receiving visual-aided instruction on subacromial injections (SAI) will demonstrate differences in accuracy and technique. METHODS: During Spring of the year 2022, 24 Internal Medicine and Family Medicine residents were randomly divided into control and intervention groups to participate in this interventional randomized cadaveric study. Each group received SAI instruction via lecture and video; the intervention group practiced on cadavers under mentored guidance. Subjects underwent a simulated patient encounter culminating in injection of latex dye into a cadaveric shoulder. Participants were evaluated based on a technique rubric, and accuracy of injections was assessed via cadaver dissection. RESULTS: Twenty-three of twenty-four participants had performed at least one MSK injection in practice, while only 2 (8.3%) of participants had performed more than 10 SAIs. There was no difference in technique between control 18.4 ± 3.65 and intervention 19.2 ± 2.33 (p = 0.54). Dissections revealed 3 (25.0%) of control versus 8 (66.7%) of intervention injections were within the subacromial space. Chi-Square Analysis revealed that the intervention affected the number of injections that were within the subacromial space, in the tissues bordering the subacromial space, and completely outside the subacromial space and bordering tissues (p = 0.03). The intervention group had higher self-confidence in their injection as opposed to controls (p = 0.04). Previous SAI experience did not affect accuracy (p = 0.76). CONCLUSIONS: Although primary care physicians and surgeons develop experience with MSK procedures in practice, this study demonstrates a role for early integrated instruction and simulation to improve accuracy and confidence. The goal of improving accuracy in MSK procedures amongst all primary care physicians may decrease costs and avoid unnecessary referrals, diagnostic tests, and earlier than desired surgical intervention.

Anatomic location of the first dorsal extensor compartment for surgical De-Quervain's tenosynovitis release: A cadaveric study.

BACKGROUND: De-Quervain's tenosynovitis is a disorder arising from the compression and irritation of the first dorsal extensor compartment of the wrist. Patients who fail conservative treatment modalities are candidates for surgical release. However, risks with surgery include damage to the superficial radial nerve and an incomplete release due to inadequate dissection. Currently, there is a paucity of literature demonstrating the exact anatomic location of the first dorsal extensor compartment in reference to surface anatomy. Thus, this cadaveric study was performed to determine the exact location of the first extensor compartment and to devise a reliable surgical incision to prevent complications. AIM: To describe the location of the first dorsal compartment in relation to bony surface landmarks to create replicable surgical incisions. METHODS: Six cadaveric forearms, including four left and two right forearm specimens were dissected. Dissections were performed by a single fellowship trained upper extremity orthopaedic surgeon. Distance of the first dorsal compartment from landmarks such as Lister's tubercle, the wrist crease, and the radial styloid were calculated. Other variables studied included the presence of the superficial radial nerve overlying the first dorsal compartment, additional compartment sub-sheaths, number of abductor pollicis longus (APL) tendon slips, and the presence of a pseudo-retinaculum. RESULTS: Distance from the radial most aspect of the wrist crease to the extensor retinaculum was 5.14 mm ± 0.80 mm. The distance from Lister's tubercle to the distal aspect of the extensor retinaculum was 13.37 mm ± 2.94 mm. Lister's tubercle to the start of the first dorsal compartment was 18.43 mm ± 2.01 mm. The radial styloid to the initial aspect of the extensor retinaculum measured 2.98 mm ± 0.99 mm. The retinaculum length longitudinally on average was 26.82 mm ± 3.34 mm. Four cadaveric forearms had separate extensor pollicis brevis compartments. The average number of APL tendon slips was three. A pseudo-retinaculum was present in four cadavers. Two cadavers had a superficial radial nerve that crossed over the first dorsal compartment and retinaculum proximally (7.03 mm and 13.36 mm). CONCLUSION: An incision that measures 3 mm proximal from the radial styloid, 2 cm radial from Lister's tubercle, and 5 mm proximal from the radial wrist crease will safely place surgeons at the first dorsal compartment.

Characterization of the MSAP Flap in Head and Neck Surgical Oncology: A 3D Cadaveric Study.

OBJECTIVES: The medial sural artery (MSA) perforator flap is a versatile free flap. However, the cutaneous perforators are not well characterized. The objectives of this pilot anatomical study were to: (1) visualize in three-dimensions, as in-situ, the origin, course, and distribution of the cutaneous perforators, (2) characterize the number and frequency of the perforators, and (3) quantify mean pedicle length. METHODS: Thirteen cadaveric specimens were dissected, digitized, and modeled in 3D. Three-dimensional models and dissection photographs were used to determine the origin, course, number, distribution, and pedicle length of MSA perforators. RESULTS: The most common pattern consisted of three perforators (39% of specimens). The maximum number of perforators identified was four (23%). The majority of specimens (92%) had a cutaneous perforator originating from the lateral branch of the MSA and coursed most frequently in the second (43%) and third (37%) quartiles of the length of the tibia. Mean pedicle length was 19.1 ± 6.9 cm. Perforators originating from the medial branch of the MSA were significantly (p < 0.05) shorter than those from the lateral branch and were found to course only in the first quartile. CONCLUSION: The 3D models constructed in this study provide a comprehensive overview of the location and course of the perforators, enabling measurement of parameters in 3D-space. Anatomical characterization of the MSA perforator flap using 3D analysis can assist reconstructive surgeons in understanding the relevant anatomy and optimizing the surgical technique for flap harvest. LEVEL OF EVIDENCE: N/A Laryngoscope, 2024.

Neglected Sprengel's deformity in an 80-year-old female cadaver: a case report.

BACKGROUND: Sprengel's deformity is a congenital abnormality of the shoulder girdle. Because scapular retraction, such as the Green procedure, is usually performed during childhood to improve esthetics and shoulder function, Sprengel's deformity is rarely found in older patients. CASE PRESENTATION: We presented a unique case of a Japanese female cadaver with Sprengel's deformity at the age of 80 years. Anatomical dissection and radiological imaging revealed musculoskeletal anomalies associated with Sprengel's deformity, including Klippel-Feil syndrome, presence of an omovertebral bone, and absence of the trapezius muscle. In addition, bilateral cervical ribs were in contact with the brachial plexus. These anomalies may lead to numbness, pain, and limited range of motion of the neck and upper girdle with aging. CONCLUSIONS: Because most adult patients with Sprengel's deformity experience neck pain and limited movement of the shoulder, the presented case is a rare case of neglected Sprengel's deformity in an 80-year-old cadaver.