Purpose: The aim of the present study was to evaluate the time and the safety of the procedure to perform an infraclavicular approach to the subclavian vessels for damage control of major vascular injuries of the upper extremity in the shoulder region using a cadaver model for non-thoracic surgeons. Methods: A sample of 100 orthopaedic trauma residents, specialists, and attendings was recruited from an AO cadaveric dissection course in Graz, Austria, on extremity access. Emergency infraclavicular access to the subclavian vessels was performed on 50 cadavers on 2 consecutive days. Attention was paid to time, successful clamping of the vessels, self-assessment and learning curve. Results: First day: Only 9 (27%) participants felt safe among the 33 participants who performed correct emergency access including clamping of the correct vessels on the first day. Second day: 55 (71%) of the 77 participants who correctly clamped the subclavian vessels on the second day reported feeling safe. Comparing day 1 to day 2 we found an improvement of 35% (subclavian artery) and 37% (subclavian vein) in the correct identification of subclavian vessels in our sample. The evaluations of this study show that there is no correlation between surgical experience and successful emergency access. Conclusion: The value of anatomic dissections is therefore of major importance to teach unusual techniques This study shows the importance and effectiveness of anatomical dissection courses and anatomical learning. To sum up, it can be said that correct self-assessment can be improved through practice.

Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) may be useful in treating exsanguinating trauma patients. This study seeks to compare rates of success, complications and time required for vascular access between ultrasound-guidance and surgical cut-down for femoral sheath insertion as a prospective observational case control study. Participating clinicians from either trauma surgery or anesthesiology were allocated to surgical cut-down or percutaneous ultrasound-guided puncture on a 1:1 ratio. Time spans to vessel identification, successful puncture, and balloon inflation were recorded. 80 study participants were recruited and allocated to 40 open cut-down approaches and 40 percutaneous ultrasound-guided approaches. REBOA catheter placement was successful in 18/40 cases (45%) using a percutaneous ultrasound guided technique and 33/40 times (83%) using the open cut-down approach (p < 0.001). Median times [in seconds] compared between percutaneous ultrasound-guided puncture and surgical cut-down were 36 (18–73) versus 117(56–213) for vessel visualization (p < 0.001), 136 (97–175) versus 183 (156–219) for vessel puncture (p < 0.001), and 375 (240–600) versus 288 (244–379) for balloon inflation (p = 0.08) overall. Access to femoral vessels for REBOA catheter placement is safer when performed by cut-down and direct visualization but can be performed faster by an ultrasound-guided technique when vessels can be identified clearly and rapidly.

Introduction: Immediate posterior pelvic ring stabilization is the prerequisite for pelvic packing. In patients “in extremis”, often no adequate positioning or imaging is available. Percutaneous application of a stabilizing K-wire or even a screw at the posterior pelvic ring can give adequate stability without an increased risk damage to surrounding structures, when respecting classical landmarks. Materials and Methods In 10 human adult whole-body cadavers, a percutaneous application of a 2.8mm K-wire was performed with only an a.p. image intensifier x-ray available. The classical entry point for iliosacral screw fixation was used. Control imaging, including a.p., Inlet and Outlet views confirmed the position of the K-wire using an Arcadis© Orbic 3D C-arm (SIEMES; Solothum, Switzerland). Results In 16 of 20 hemipelves (80%), in all three standard radiographic planes, the K-wire was in the expected anatomic position. Malposition was observed as usually too anterior positioning of the wire in relation to the sacrum. Conclusions Using standard landmarks, percutaneous application of K-wires into the posterior pelvic ring using only a.p. x-rays was found to be safe with few mal-placements. The complication rate is comparable to mal-placement of pelvic C-clamp pins. This technique is feasible in patients in extremis.

Summary Background The aim of this anatomical study was to evaluate the course of the extensor pollicis longus (EPL) tendon, its positional relationship to adjacent structures, and the resulting clinical relevance under consideration of various functional positions. Materials and methods Twenty upper extremities from ten adult human cadavers embalmed using Thiel’s method were included in this study. The greatest possible movement/slippage of the EPL tendon, the angle at which the tendon wraps around Lister’s tubercle, and its course across the extensor carpi radialis longus and brevis (ECRL and ECRB) were recorded and defined in all functional positions. Results Our findings demonstrate a high range of motion of the tendon in relation to clinically relevant structures. Conclusion Understanding the anatomical course of the EPL tendon, its potential extent of movement, and its resulting positional changes is essential for the diagnosis and surgical treatment of patients with complaints or injuries in the dorsoradial wrist region.

Purpose The purpose of this study was to evaluate the applicability and potentially associated harms of emergency access to the femoral artery and vein in a sample of physicians working together in the emergency department of a level I trauma center. In addition, to investigate whether there are differences between participants in terms of different levels of training. Methods A sample of 36 orthopedic trauma and anesthesiology assistant doctors, specialists, and senior physician was recruited from the emergency room management at a level I trauma center in Graz, Austria. Emergency approach to the femoral vessels was performed on 33 fresh cadavers. Attention was paid to time, successful clamping of the vessels, self-assessment and learning curve. Results The approach was performed correctly in 97.2% (35/36) of all cases. 97.2% of all participants (35/36) were confident to perform the emergency access. They were proven right, since especially the resident and senior subgroups achieved satisfactory results concerning the correct performance of the approach to the femoral vessels as well as correct identification of the femoral artery and vein. Conclusion In conclusion, we evaluated the emergency access to the femoral artery (FA) and femoral vein (FV) as an easily teachable procedure including high success rates (correct performance in 97.2%).

Purpose To project the distance between the tip of the greater tubercle (GT), respectively, the proximal border of the tip of the coracoid process (CP) and the entry point of the coracobrachialis by the musculocutaneous nerve (MCN) proportionally onto the humeral length. Methods Sixty-six upper extremities were included in the study. The distance between the tip of the GT and the distal tip of the lateral humeral epicondyle (LE) was evaluated as the humeral length (HL). The interval between the tip of the GT and the entry point of the coracobrachialis muscle by the MCN was measured. The distance between the proximal border of the tip of the CP and the distal portion of the medial humeral epicondyle (ME) and the entry point of the MCN into the coracobrachialis were evaluated. Proportions were used to project the entry point of the coracobrachialis by the MCN along the HL, respectively, the interval between the proximal border of the tip of the CP and the distal tip of the ME. Results The entry point of the MCN into the coracobrachialis muscle can be expected at an interval between 14.9 and 33.9% of the HL (between the tip of the GT and the LE), starting from the tip of the GT. Regarding the reference line between the proximal border of the CP and the ME, the nerve’s entry point was located between 14.2 and 34.4%, starting from the CP. Conclusion Results represent easily applicable intervals for intraoperative localisation of the MCN.

Purpose Surgical simulations are becoming increasingly relevant in musculoskeletal training. They provide the opportunity to develop surgical skills in a controlled environment while reducing the risks for patients. For K-wire internal fixation in musculoskeletal surgery, a force feedback virtual reality (VR) simulator was developed. The aim of this study was to evaluate training results using this technology and compare the results with that of standard teaching on cadavers. Methods Twenty participants attending an AO Trauma Course during 2020 were randomly allo-cated in 2 groups. On day 1, group A was trained by senior surgeons using a cadaver and group B was trained by the VR simulator for K-wire insertion in the distal radius. On day 2, all participants performed K-wire insertion on the cadaver model, without assistance, to validate the training effect. Results On a surgical skills test, group B performed better than group A. In group B, the entry point of the first K-wire was closer to the targeted styloid process of the radius, and the protrusion of the K-wires into soft tissue was less than that in group A. Conclusions Training with the VR simulator for K-wire insertion resulted in better surgical skills than training by a surgeon and cadaver model.Copyright (c) 2022 by the American Society for Surgery of the Hand. All rights reserved.

Introduction The zygapophyseal joints represent one possible cause for back pain. Therefore, many interventions are targeting the denervation of the facet joints. The aim of this study is to describe the course of the medial branch of the dorsal branch of the spinal nerve and its articular branches to the zygapophyseal joints in the segments T10-T12. Methods The medial branches in the thoracic segments T10-T12 were dissected in 20 Thiel embalmed cadavers. An Eschenbach magnifying glass (4.0x magnification) was used during dissection preserving the articular branches. The topography and the branching pattern of the medial branches was observed. Results The course of the nerves in the segments T10-T12 differed from each other because of the different osseous anatomy of each segment. The medial branch at the segment T10 crossed the tip of the transverse process in 28 of the 40 hemivertebral specimens. In the remaining cases it passed superior to the transverse process. At T11 the medial branch ran constantly through an osteofibrous canal. At the segment T12 the medial branches showed a similar course to the medial branches in the lumbar region. In many cases two articular branches, which arose from the medial branch were identified. Conclusions The results of this study show a considerable anatomic variety at the segment T10. It also demonstrates that the transverse process is an important landmark to encounter the medial branch. Furthermore, the possibility of a double innervation of the facet joints should always be considered.

The study goal was to evaluate the distances from the radial (RN), the musculocutaneous (MN) and axillary nerves (AN) and the medial neurovascular bundle of the upper arm to a minimally invasive applied plate and to define its relation to the RN during different degrees of malrotation during MIPO. The sample involved ten upper extremities. Application of a PHILOS plate was performed through a Delta-split. Intervals between the AN, MN, RN and the medial vascular bundle were defined at various positions. The humeral shaft was artificially fractured at a height of about the mean of the plate. The distal fragment was brought into 15° and 30° internal (IR) as well as external rotation (ER) and here, the plate's relation to the RN was evaluated. The medial neurovascular bundle intersected the plate at its distal part in two specimens. Regarding the distances from the RN to the plate during different rotation positions the distances became significantly longer during ER, respectively shorter during IR. The medial neurovascular bundle and the RN were identified as the main structures at risk. Care must be taken during distal screw placement and malrotation exceeding 15° must be avoided during MIPO.

Background: The aim of the study was to design a convenient technique for dorsal minimally invasive plate osteosynthesis (MIPO) of extra-articular fractures of both distal thirds of the humeral shaft as well as to characterise the course and proximity of the radial nerve (RN) and the axillary nerve (AN).Methods: The collective consisted of 20 upper extremities of human adult body donors. A 3.5 mm Locking Compression Plate (LCP), an extra-articular distal humerus plate was inserted through a MIPO approach including two incisions. The primary incision was performed 5 cm in lenght on the dorsal side of the lateral epicondyle. An additional 5 cm incision was conducted distal to the humeral deltoid muscle insertion and the RN was depicted. The longest suitable plate was advanced under nerve protection starting distally and fixed by locking screws. A third incision with a length of 5 cm was made beginning at the distal border of the deltoid muscle, and a muscle split was performed to dissect the AN. The respective plate holes, where the AN and RN were located and the distances between the nerves were examined.Results: The RN was mostly (30%) localised on holes 6 and 7 (starting distally). The AN laid directly on the plate in 65% and on the most proximal plate hole in 12 cases, but was never situated underneath the plate. The distance between the AN and RN was at mean 93.5 mm.Conclusions: MIPO via a dorsal method proves to be a noteworthy technique and valuable option as in-dicated by our results. This 5-5-(5) concept may be performed as a two-incision or three-incision technique for extra-articular fractures of both distal thirds of the humerus.(c) 2022 Published by Elsevier GmbH.

Introduction Percutaneous radiofrequency facet denervation (PRFD) by thermocoagulation is a useful treatment for nonspecific thoracic pain syndrome. To guarantee that maximal thermal lesion is applied to the nerve, it is essential to have precise knowledge of the topography of the thoracic dorsal branches of the spinal nerves. This special anatomy was investigated, and the results were compared with the existing technique for PRFD, where the active needle tip is placed in the junction of the superior articular process and the transverse process. Methods Twenty thoracic spines of cadavers (10 females and 10 males) embalmed according to Thiel's method were bilaterally dissected. After careful removal of skin and subcutaneous fat tissue, the lateral and medial branches were traced centrally. In addition, the articular branch to the thoracic facet joint was traced peripherally. The distance of the medial branch to the inferior articular process at the level of the nerve passing the superior costotransverse ligament was measured. Results The dorsal branch bifurcates into lateral and medial branches medial to the superior costotransverse ligament. The medial branch runs laterally first to pass in between two parts of the intertransverse ligament running dorsally and to turn medially superficial to this ligament. The zygapophysial branch always originated from the medial branch passing the inferior articular process laterally by running caudally to turn medially and send branches to the capsule of the zygapophyseal joint. The distance of the medial branch lateral to the inferior articular process was constantly 3 mm. Conclusions The current technique of PRFD at the thoracic spine targets the medial branch distal to the separation of the articular branch, rendering the lesion ineffective at denervating the zygapophyseal joint. For selective thermocoagulation of the articular branches of the thoracic zygapophyseal joint, a new technique should be developed. We propose an anatomically informed needle position that can now be confirmed clinically.

This study aims to evaluate the relation between the lumbosacral trunk (LT) and the sacro-iliac joint (SIJ). In forty anatomic specimens (hemipelves) a classical antero-lateral approach to the SIJ was performed. The SIJ was marked at the linea terminalis (reference point A). Reference point B was situated at the upper edge of the interosseous sacro-iliac ligament. The length of the SIJ (distance A to B) and the distance between point A and the ventral branch of the fourth (L4) and fifth (L5) lumbar spinal nerves at the linea terminalis were measured. The SIJ had a mean length of 58.0 mm. The ventral branch of L5 was located closer to the SIJ in very long SIJs (mean length: ≥ 6.5 cm; mean distance: 9.8 mm) compared to very short joints (≤ 5 mm; mean distance: 11.3 mm). For the ventral branch of L4, very long SIJs had a mean distance of 7 mm and very short joints an average distance of 9.7 mm between point A and the nerve branch. A safe zone of approximately 1 cm to 2 cm (anterior to posterior) is present on the sacral surface (lateral to medial) for safe fixation of plates during anterior plate stabilization of the SIJ. Pelves with a shorter dorsoventral diameter of the most superior part of the SIJ apparently give more space for inserting plates.

Background: The aim of this study was to investigate the axillary nerve’s location along superficial anatomical landmarks, and to define a convenient risk zone. Methods: A total of 123 upper extremities were evaluated. After dissection of the axillary nerve, the vertical distance between the upper border of the anterolateral edge of the acromion and the proximal border of the nerve was measured. Furthermore, the interval between the proximal border and the distal border of the axillary nerve’s branches was evaluated. The interval between the distal border of the branches and the most distal part of the lateral humeral epicondyle was measured. The distance between the anterolateral edge of the acromion and the lateral humeral epicondyle was evaluated. Measurements were expressed as proportions with respect to the distance between the acromion and the lateral humeral epicondyle. Results: The distance between the acromion and the proximal border of the axillary nerve’s branches was at a height of 10 percent of the distance between the acromion and the lateral humeral epicondyle, starting from the acromion (90 percent when starting from the lateral humeral epicondyle). The interval between the proximal and distal margins of the axillary nerve’s branches was between 10 percent and 30 to 35 percent of this interval, starting from the acromion (65 to 70 percent when starting from the lateral humeral epicondyle). Conclusions: The authors were able to locate the branches of the axillary nerve at an interval between 10 and 35 percent of the distance between the acromion and the lateral humeral epicondyle, starting from the acromion. This makes the proximal third of this distance an easily applicable risk zone during shoulder surgery.

Background: The aim of this study was to investigate proximal humerus plating regarding drill depth and over penetration of the glenohumeral joint and to find a relation between these findings and different areas of bone mineral density (BMD) in the humeral head. Material & Methods: The study sample involved 45 upper extremities from human adult cadavers. Two different plates (HOFER; PHILOS) were applied to the proximal humerus. Each hole was drilled until the respective participant thought to have placed the drill bit subchondral. Next, penetration of the far cortex was conducted to determine the residual bone stock. Additionally, the point of screw penetration of the far cortex was identified for each hole of the plates and allocated to five regions with different bone mineral density as described by Tingart et al. Results: The screw penetration rate and the residual bone stock were compared within the 5 BMD regions. A significantly thicker residual bone stock was found at the central region (SD +/- 13.1 mm) than in the anterior region (SD +/- 9.5 mm) and in the posterior region (SD +/- 8.5 mm). The anterior region revealed a significantly higher penetration rate than the posterior region (p = 0.01) and the central region (p = 0.03). Conclusion: The anterior region of the humeral head was associated with a higher over penetration rate of the far cortex into the glenohumeral joint and a decreased bone stock after subchondral drilling representing a reduced bone mineral density (BMD). (C) 2020 Elsevier Ltd. All rights reserved.

Introduction: Percutaneous vertebral augmentation is a common therapeutic approach for osteoporotic or osteolytic vertebral fractures. Due to the variable pedicle anatomy two different approaches, the transpedicular and the extrapedicular approach have been established. In particular, in the middle and upper thoracic spine, percutaneous procedures are challenging because of difficult visualisation of anatomical landmarks and a more unfavourable anatomy with smaller and differently orientated pedicles. Material and methods: In our cadaveric study we compared the transpedicular and the extrapedicular approach to the thoracic spine. In 26 cadaveric spine specimes, embalmed using Thiel's method, we placed a total of 486 trans- and extrapedicular K-wires through Jamshidi needles in the vertebral bodies T4 - T12 under fluoroscopy. A CT scan was then performed to verify the actual position of the K-wire. Malpositioning was defined as deviation from the planned approach or placement of the K-wire in the spinal canal or outside the vertebral body. Number and direction of malpositionings was recorded. Results: Malpositioning occurred in 68 of 468 K-wires. It was more frequent in the transpedicular (54) than in the extrapedicular (14) approach. Intraspinal malposition was seen more often in the transpedicular approach (n=36) especially in the upper and middle thoracic spine. Conclusion: In summary both approaches are relatively safe but in the upper and middle thoracic spine the risk of intraspinal malpositioning seems to be lower when using the extrapedicular approach. (C) 2021 Published by Elsevier Ltd.

BACKGROUND:Distances between anatomic landmarks and anatomic structures at risk are often underestimated by surgeons. PURPOSE:The goal of the study was to evaluate the distances between anatomic landmarks and the spermatic cord in case of anterior plating of the symphysis. METHODS:A total of 25 pelves (50 hemipelves) of male embalmed cadavers were dissected. A 5-hole 3.5mm locking compression plate (Synthes GmbH) was fixed from directly anterior on the symphysis. Measurements were taken 1) distance between the tips of both pubic tubercles, 2) horizontal interval between the lateral border of the plate and the medial margin of the SC (bilateral), 3) distances between the medial border of the SC and the tip of the pubic tubercle (bilateral), 4) distances between the medial border of the SC and the lateral basis of the pubic tubercle (bilateral). RESULTS:The distance between the pubic tubercles was 60.3mm in average (SD: 5.7). The interval between the lateral border of the plate and the medial margin of the SC was on average 4.5mm (SD: 1.9) on the right and 4.7mm (SD: 2.6) on the left side. The distance between the tip of the pubic tubercle and the medial border of the SC was in average 11.2mm (SD: 2.7) on the right, and 11.0mm (SD: 2.7) on the left side. The average distance between the medial border of the SC and the lateral basis of the pubic tubercle was 8.1mm (SD: 2.4) on the right and 8.2 mm (SD: 2.4) on the left side. CONCLUSION:The SC is at risk not only during dissection but also during anterior plating of the symphysis, because of its close relation to the SC. CLINICAL RELEVANCE:Average distances between the palpable pubic tubercle and the SC are below one finger breadth (as reference).

BACKGROUND:Chronic exertional compartment syndrome (CECS) is a recognized clinical diagnosis in running athletes and military recruits. Minimally invasive fasciotomy techniques have become increasingly popular, but with varied results and small case numbers. Although decompression of the anterior and peroneal compartments has demonstrated a low rate of iatrogenic injury, little is known about the safety of decompressing the deep posterior compartment.PURPOSE:To evaluate the risk of iatrogenic injury when using minimally invasive techniques to decompress the anterior, peroneal, and deep posterior compartments of the lower leg.STUDY DESIGN:Descriptive laboratory study.METHODS:A total of 60 lower extremities from 30 adult cadavers were subject to fasciotomy of the anterior, peroneal, and deep posterior compartments using a minimally invasive technique. Two common variations in surgical technique were employed to decompress each compartment. Anatomical dissection was subsequently carried out to identify incomplete division of the fascia, muscle injury, neurovascular injury, and the anatomical relationship of key neurovascular structures to the incisions.RESULTS:Release of the anterior and peroneal compartments was successful in all but 2 specimens. There was no injury to the superficial peroneal nerve or any vessel in any specimen. A transverse incision crossing the anterior intermuscular septum resulted in muscle injury in 20% of the cases. Release of the deep posterior compartment was successful in all but 1 specimen when a longitudinal skin incision was used, without injury to neurovascular structures. Compared with a longitudinal incision, a transverse skin incision resulted in fewer complete releases of the deep posterior compartment and a significantly higher rate of injury to the saphenous nerve (16.7%; P = .052) and long saphenous vein (23.3%; P = .011).CONCLUSION:Minimally invasive fasciotomy of the anterior, peroneal, and deep posterior compartments using longitudinal incisions had a low rate of iatrogenic injury in a cadaveric model. Complete compartment release was achieved in 97% to 100% of specimens when employing this technique.CLINICAL RELEVANCE:Minimally invasive fasciotomy techniques for CECS have become increasingly popular with purported low recurrence rates, improved cosmesis, and faster return to sport. It is important to determine whether this technique is safe, particularly given the variable rates of neurovascular injury reported in the literature.