Quadrilateral Space Research Articles

VARIATIONS OF ORIGIN AND DISTANCE OF AXILLARY NERVE: A DESCRIPTIVE STUDY

Background: Axillary nerve, one of the terminal branches of posterior cord of brachial plexus is more prone for injuries. Lack of proper anatomical knowledge and variations of axillary nerve leads to risk of nerve injuries. The present study describes the origin of axillary nerve, its distance of origin from tip of coracoids process. Method: Thirty brachial plexuses from fifteen formalin fixed human cadavers of both the sexes were studied by dissection method. Origin and branching pattern of axillary nerve and its distance of origin from the anteromedial aspect of tip of coracoid process & posterolateral aspect of acromion process was recorded. Results: Out of the 30 specimens studied, axillary nerve was originating from the posterior cord of brachial plexus in 90% of specimens, remaining 10% specimens showed a common trunk of origin of axillary nerve from posterior cord of brachial plexus. The mean distance of origin of axillary nerve from the anteromedial aspect of tip of coracoid process and posterolateral aspect of acromion process is 3.98cm & 6.30cm respectively. The axillary nerve terminated into anterior and posterior branch within quadrangular space in 29 specimens. In one specimen articular branch for shoulder joint was not directly arising from axillary nerve instead it is arising from anterior branch of axillary nerve. Conclusion: In studied population Axillary nerves display variations in the origin and distance of origin. Knowledge of this variation in axillary nerve is very important to clinicians, anaesthetists and orthopaedic surgeons during surgical exploration of neck, axilla and upper arm, shoulder dislocation, infraclavicular brachial plexus block and fracture of surgical neck of humerus.
 Keywords: Axillary nerve; Posterior cord; Coracoid process; Acromion process.

Quadrilateral Space Syndromeを合併した腱板損傷の一例

Quadrilateral Space Syndromeを合併した腱板損傷の一例

Ultrasound-guided anterior approach to the axillary and intercostobrachial nerves in the axillary fossa: an anatomical investigation

BackgroundThe posterolateral and medial aspect of the arm is supplied by the axillary (AXN) and intercostobrachial nerves (ICBN), which are not anaesthetised by an axillary brachial plexus block (ABPB). Blockade of the AXN and the ICBN has been reported in the quadrangular space (QS) posteriorly or by serratus plane block, respectively. An anterior ultrasound-guided approach to block the AXN and ICBN would be desirable to complete an ABPB at a single insertion site. MethodsAfter a preliminary dissection study in six cadavers, ultrasound-guided AXN and ICBN injection was performed in 46 Thiel embalmed cadavers bilaterally. Key sonographic landmarks to identify the AXN in the QS are the humerus, teres major muscle, and subscapular muscle. With the same probe position, the ICBN was identified in the subfascial axillary space. Then, 2 ml latex was injected at each nerve and confirmed by dissection. ResultsMuscular and bony landmarks were identified in all cadavers. The AXN was seen in 99% in the QS or at the inferolateral margin of the subscapular muscle and surrounded by latex in 96% of cases. Latex spread to the axillary fossa, within the subscapular muscle, or to the radial nerve was noted in 8% of the injections. The ICBN was seen and surrounded by latex in 100% of cases. ConclusionsWe describe a reliable ultrasonographic approach to visualise the AXN and ICBN anteriorly from the conventional ABPB approach as confirmed in this cadaver study.

Origin of radial collateral artery from the posterior circumflex humeral artery in the quadrangular space of the shoulder region – an abnormality which could enhance the complications of quadrangular space syndrome

Origin of radial collateral artery from the posterior circumflex humeral artery in the quadrangular space of the shoulder region – an abnormality which could enhance the complications of quadrangular space syndrome

Quadrilateral Space Syndrome: Diagnosis and Clinical Management.

Quadrilateral space syndrome (QSS) is a rare disorder characterized by axillary nerve and posterior humeral circumflex artery (PHCA) compression within the quadrilateral space. Impingement is most frequently due to trauma, fibrous bands, or hypertrophy of one of the muscular borders. Diagnosis can be complicated by the presence of concurrent traumatic injuries, particularly in athletes. Since many other conditions can mimic QSS, it is often a diagnosis of exclusion. Conservative treatment is often first trialed, including physical exercise modification, physical therapy, and therapeutic massage. In patients unrelieved by conservative measures, surgical decompression of the quadrilateral space may be indicated.

Challenges in Rating Multiple Upper Extremity Conditions: A Case of Quadrilateral Space Syndrome and Medial Elbow Injury

Abstract Physicians sometimes are challenged with clinical presentations that do not fit perfectly within the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides); in such cases, the evaluator is instructed to apply clinical judgment and common sense when determining an impairment, with particular consideration of the effect of the medical condition on the individual's activities of daily living. In this case presentation, a 35-year-old male private security guard injured his right elbow performing a bench press while on assignment. After magnetic resonance imaging and electrodiagnostic evaluation, the patient underwent surgery that included a medial elbow Nirschl procedure and an ulnar nerve submuscular transposition. The patient underwent twelve months of rehabilitation, but he continues to experience a pins-and-needles sensation and perceives upper arm strength loss. Twenty-four months after surgery, the patient declines surgical treatment for quadrilateral space syndrome and presents for an impairment rating evaluation. Accepted medical conditions under the workers’ compensation program include quadrilateral space syndrome, medial epicondylopathy, and ulnar nerve entrapment at the elbow (cubital tunnel syndrome). The AMA Guides, Sixth Edition, does not include a listing for quadrilateral space syndrome, and the author discusses the challenges of teasing out functional limitations when multiple diagnoses are present within the same limb. Evaluators should note that the AMA Guides recommends using the impairment rating that most closely represents the actual functional loss.

The Endoscopic Endonasal Transmaxillary Approach to Meckel's Cave Through the Inferior Orbital Fissure.

Surgical access to Meckel's Cave (MC) is challenging due to its deep location and surrounding important neurovascular structures. Currently existing endoscopic endonasal (EE) approaches require dissecting near the internal carotid artery (ICA) or require transposition of the pterygopalatine neurovascular bundle. To describe a novel approach to access the anterolateral aspect of the MC using a minimally invasive EE route. The EE transmaxillary transinferior orbital fissure approach was simulated in 10 specimens. The approach included an ethmoidectomy followed by an extended medial maxillectomy with transposition of the nasolacrimal duct. The infraorbital fissure was opened, and the infraorbital neurovascular bundle was transposed inferiorly. A quadrilateral space, bound by the maxillary nerve inferomedially, ophthalmic nerve superomedially, infraorbital nerve inferolaterally, and floor of the orbit superolaterally, was exposed. The distances from the foramen rotundum (FR) to the ICA, orbital apex (OA), and infratemporal crest (ITC) and from the OA to the ICA and ITC were measured. The distances obtained were FR-ICA = 19.42 ± 2.03 mm, FR-ITC = 18.76 ± 1.75mm, FR-OA = 8.54 ± 1.34 mm, OA-ITC = 19.78 ± 2.63 mm, and OA-ICA = 20.64 ± 142 mm. Two imaginary lines defining safety boundaries were observed between the paraclival ICA and OA, and between the OA and ITC (safety lines 1 and 2). The reported approach provides a less invasive route compared to contemporary approaches, allowing expanded views and manipulation anteromedial and anterolateral to MC. It may be safer than the existing approaches as it does not require transposition of the ICA, infratemporal fossa, and pterygopalatine fossa, and allows access to tumors located anteriorly on the floor of the middle cranial fossa.

Accessory subscapularis muscle – A forgotten variation?

The quadrangular space is a space in the axilla bounded by the inferior margin of the teres minor muscle, the superior margin of the teres major muscle, the lateral margin of the long head of the triceps brachii muscle and the surgical neck of the humerus, medially. The axillary nerve (C5-C6) and the posterior circumflex humeral artery and veins pass through this space in order to supply their territories. The subscapularis muscle is situated into the scapular fossa and inserts itself into the lesser tubercle of the humerus, thus helping stabilize the shoulder joint. A supernumerary muscle known as accessory subscapularis muscle originates from the anterior surface of the muscle and usually inserts itself into the shoulder joint. It is a rare variation with few reports of its existence and incidence. We present a case of the accessory subscapularis muscle in a male cadaver fixated with a 10% formalin solution. The muscle passed anteriorly to the axillary nerve, thus, predisposing an individual to quadrangular space compression syndrome. We perform a review of the literature and address its clinical, anthropological and anatomical significance.

Anatomical nuances of the internal carotid artery in relation to the quadrangular space

OBJECTIVE The aim of this study was to evaluate the anatomical variations of the internal carotid artery (ICA) in relation to the quadrangular space (QS) and to propose a classification system based on the results. METHODS A total of 44 human cadaveric specimens were dissected endonasally under direct endoscopic visualization. During the dissection, the anatomical variations of the ICA and their relationship with the QS were noted. RESULTS The space between the paraclival ICAs (i.e., intercarotid space) can be classified as 1 of 3 different shapes (i.e., trapezoid, square, or hourglass) based on the trajectory of the ICAs. The ICA trajectories also directly influence the volumetric area of the QS. Based on its geometry, the QS was classified as one of the following: 1) Type A has the smallest QS area and is associated with a trapezoid intercarotid space, 2) Type B corresponds to the expected QS area (not minimized or enlarged) and is associated with a square intercarotid space, and 3) Type C has the largest QS area and is associated with an hourglass intercarotid space. CONCLUSIONS The different trajectories of the ICAs can modify the area of the QS and may be an essential parameter to consider for preoperative planning and defining the most appropriate corridor to reach Meckel's cave. In addition, ICA trajectories should be considered prior to surgery to avoid injuring the vessels.

Arthroscopic-assisted exploration of the axillary nerve through a posterior open approach: A novel technique

Previous studies have described a segment of the axillary nerve (AN) that cannot be surgically explored through standard open surgical approaches (blind zone). This study aimed to evaluate the feasibility of combining the standard posterior approach to the AN by using an arthroscope to visualize all segments of the AN. Four fresh-frozen shoulders in two adult human torsos were included in the study. A standard posterior approach was performed on each shoulder, and a dry arthroscopy was performed through the surgical opening in an attempt to visualize all the segments of the AN. A surgical clip was placed at the most proximal and anterior segment of the AN that could be visualized with the arthroscope. A standard open deltopectoral approach was then performed to determine the exact location of the surgical clip and its relation to the origin of the AN. All segments of the AN (including the blind zone) were visualized from the quadrilateral space to their origin from the posterior cord in all four specimens. The surgical clip was found at an average of 1cm (range from 0.5 to 1.5cm) from the origin of the AN from the posterior cord. This cadaveric study shows that it is feasible to visualize all segments of the AN (including the blind zone) using this novel approach that combines the use of the standard posterior approach to the AN with dry arthroscopic exploration. Clinical studies are necessary to evaluate the utility of this novel approach.

Aphasia's quarrel

Aphasia's quarrel

Cadaveric Study of the Articular Branches of the Shoulder Joint.

This cadaveric study investigated the anatomic relationships of the articular branches of the suprascapular (SN), axillary (AN), and lateral pectoral nerves (LPN), which are potential targets for shoulder analgesia. Sixteen embalmed cadavers and 1 unembalmed cadaver, including 33 shoulders total, were dissected. Following dissections, fluoroscopic images were taken to propose an anatomical landmark to be used in shoulder articular branch blockade. Thirty-three shoulders from 17 total cadavers were studied. In a series of 16 shoulders, 16 (100%) of 16 had an intact SN branch innervating the posterior head of the humerus and shoulder capsule. Suprascapular sensory branches coursed laterally from the spinoglenoid notch then toward the glenohumeral joint capsule posteriorly. Axillary nerve articular branches innervated the posterolateral head of the humerus and shoulder capsule in the same 16 (100%) of 16 shoulders. The AN gave branches ascending circumferentially from the quadrangular space to the posterolateral humerus, deep to the deltoid, and inserting at the inferior portion of the posterior joint capsule. In 4 previously dissected and 17 distinct shoulders, intact LPNs could be identified in 14 (67%) of 21 specimens. Of these, 12 (86%) of 14 had articular branches innervating the anterior shoulder joint, and 14 (100%) of 14 LPN articular branches were adjacent to acromial branches of the thoracoacromial blood vessels over the superior aspect of the coracoid process. Articular branches from the SN, AN, and LPN were identified. Articular branches of the SN and AN insert into the capsule overlying the glenohumeral joint posteriorly. Articular branches of the LPN exist and innervate a portion of the anterior shoulder joint.

Characteristics of Vowel Formants, Vowel Space, and Speech Intelligibility Produced by Children Aged 3-6 Years

Purpose: This study measured vowel formants and vowel space area from 3 to 6 year-old Korean children in Jeju Island to investigate their characteristics of vowel production and speech intelligibility. Methods: A total of 80 children (10 boys and 10 girls for each age) participated. For obtaining the formants, 7 Korean vowels (/a/, /e/, /i/, /o/, /u/, / m/, /^/) were used. Vowel space areas (triangular, quadrangular) and speech intelligibility were calculated and compared based on gender and age. Results: Results showed that F1 and F2 of / e/ and /i/ vowels were significantly different as age. In particular, front vowel /e/ and /i/ was significantly lower in 3 years of age but was gradually increased with age. For gender, F2 of vowel /a/ and /e/ were significantly higher in girls while F2 of vowel /i/ was significantly higher in boys (p < 0.05). With respect to vowel space area, significant differences were found in ages (p < 0.05) whereas no differences in gender (p > 0.05). Speech intelligibility was significantly different in age (p < 0.05) while no significant difference was observed in gender (p > 0.05). Significant relationships were found between triangular vowel space areas (r = 0.299, p < 0.01) or quadrilateral vowel space areas (r = 0.570, p < 0.01) and speech intelligibility. Conclusion: Accordingly, quadrilateral vowel space area composed of / i-e-a-u/ was more sensitive than triangular vowel space area composed of /i–a-u/, reflecting the vowel movement space and speech intelligibility objectively.

Partial Radial Nerve Transfers for Patients with Isolated Traumatic Axillary Nerve Injuries: Level 4 Evidence

There is no financial information to disclose. Isolated axillary nerve injuries can occur subsequent to trauma or as a direct complication from shoulder procedures. While partial radial to axillary nerve transfers have previously been described, there has been a lack of information related to patient selection, surgical methodology, and outcomes. We hypothesize that partial radial to axillary nerve transfers is an under-utilized, promising treatment option for patients with this devastating injury. We performed a retrospective analysis of all partial radial nerve transfers for isolated axillary nerve injuries (n = 7) performed by a single surgeon at 1 institution over the past 4 years. All patients had nerve conduction studies verifying a complete axillary nerve lesion with no reinnervation as detailed by fibrillation potentials without evidence of nascent potentials. The surgery consisted of (1) using a direct posterior approach to the arm, (2) isolating one fascicle of the radial nerve responsible for only elbow flexion as confirmed by intra-operative monitoring, and (3) coapting this branch to the proximal portion of the axillary nerve in the quadrilateral space. All patients were protected in a shoulder sling for 3 weeks until the nerve repair healed. There was no donor nerve deficit for any patient. Four of the 7 patients had undergone previous shoulder surgery and had received a preoperative nerve block. One patient had the nerve transfer performed within 4 months of injury and regained functional motion with forward elevation to 160 degrees and M4 strength. The other patients had surgery after the initial 7 months after the injury and did not have any meaningful improvement in function after the nerve transfer. The other 3 patients had an axillary nerve injury related to a traumatic injury and had nerve transfer performed within the initial 6 month time period. One patient has subsequent restoration of his deltoid muscle; however, his range of motion was limited due to an underlying proximal humerus nonunion. The other 2 patients have forward elevation to 160 degrees with M4 strength. •For patients with axillary nerve injuries, a partial radial to axillary nerve transfer is a safe procedure without donor deficit that can provide functional recovery with early intervention.•While the expanded use of regional anesthesia may cloud the initial post operative exam for patients undergoing shoulder surgery, the surgeon should be suspicious of patients who do not demonstrate recovery and refer patients early for intervention rather than prolonged observation in order to maximize the chances of recovery.

Vascular Quadrilateral Space Syndrome in Three Overhead Throwing Athletes: An Underdiagnosed Cause of Digital Ischemia

Vascular quadrilateral space syndrome (vQSS) is an underdiagnosed cause of extremity ischemia, pain and paresthesia in overhand throwing athletes (football throwing, volleyball, baseball).

Bilateral variant branching pattern of posterior cord of brachial plexus

ObjectiveVariant branching pattern of the cords of brachial plexus has been an area of concern for surgeons opting to explore this region. Anaesthetic blocks and surgical approaches are the highlights of these interventions, where a keen familiarization of the anatomy of this region is mandatory. Material and methodsThe present case description reports a bilateral variant branching pattern of the posterior cord in an adult male cadaver. ObservationsRight posterior cord gave upper subscapular nerve and did not give the lower subscapular nerve. Axillary nerve arises proximal to the thoracodorsal nerve. After giving thoracodorsal nerve, posterior cord continued as radial nerve. There is an unusual branch from right axillary nerve, which supplied teres major and sent twig to lower fibres of subscapularis muscle. Left upper subscapular nerve divided into two branches and supplied the subscapularis muscle. Left axillary nerve enclosed by some fibre of subscapularis muscle, within the fibres of subscapularis axillary nerve, gave an unusual branch to teres major and then it continues in quadrangular space. DiscussionIn spite uncountable reports on variations of brachial plexus, descriptions regarding anomalous branching patterns hold enormous clinical significance for the radiologists, anaesthetists and surgeons, besides being of academic interest for the anatomists.

Endoscopic endonasal study of the cavernous sinus and quadrangular space: Anatomic relationships.

The quadrangular space permits an anterior entry into Meckel's cave while obviating the need for cerebral or cranial nerve retraction. This avenue is intimately associated with the cavernous sinus; thus, from this ventral perspective, it is feasible to visualize the anteromedial, anterolateral, and Parkinson triangles. Twenty middle cranial fossae were dissected endonasally under direct endoscopic visualization. Measurements of the surface area of the quadrangular space and the ventrally accessible cavernous sinus triangles were performed using 3 coordinates under image-guided navigation. The surface area of the quadrangular space was 16.36 mm(2) (±2.89 mm(2) ). The anterolateral triangle was the largest (47.27 ± 5.37 mm(2) ), whereas Parkinson's was the smallest (22.46 ± 5.54 mm(2) ); the anteromedial triangle presented an average surface area 36.07 mm(2) (±4.15 mm(2) ). The trajectory of the internal carotid artery (ICA) significantly impacts the quadrangular space area and may be a potential parameter for defining the feasibility of this corridor. © 2016 Wiley Periodicals, Inc. Head Neck 38: E1680-E1687, 2016.

The Anatomic Basis for the Arthroscopic Latarjet Procedure

Background: The Latarjet technique is a reliable treatment option for recurrent anterior shoulder instability. However, the complication rate has been reported to be as high as 30%, with 1.6% of patients suffering a nerve injury. The all-arthroscopic Latarjet procedure has been gaining popularity, even as it has introduced its own challenges. Given that the surgeon is not able to palpate the nerves, their localization and protection can be difficult. Additionally, the use of different instruments can lead to distinct nerve injury mechanisms. Purpose: To describe the anatomic trajectory of the musculocutaneous, axillary, and suprascapular nerves in relation to the arthroscopic Latarjet approach. Using this information, guidance is provided for reducing nerve injuries during instrumentation and screw insertion. Study Design: Descriptive laboratory study. Methods: A total of 50 cadaveric shoulders from 25 whole-body specimens were examined. The specimens were placed in the beach-chair position, and the deltopectoral and dorsal approaches were used to expose the relevant structures. A subscapularis muscle split was performed between the inferior and middle thirds of the tendon. Digital caliper measurements were taken between various points of the trajectories of the nerves and surrounding anatomic landmarks. The location of the nerves relative to the split was recorded. Results: The musculocutaneous nerve lay within the split in 66% of the shoulders (n = 33); it was medial to the split in 28% (n = 14); it was found lateral to split in 2% (n = 1); and it was not identified in 4% of shoulders (n = 2). The mean length of the axillary nerve was 4.0 cm (95% CI, 3.7-4.2) from the exit of the plexus to the quadrangular space. The axillary nerve was found to be within the split in 50% of the shoulders (n = 25) and medial to the split in the remaining 50% (n = 25). The suprascapular nerve at the level of the supraspinatous fossa passed 3.3 cm (95% CI, 3.1-3.5) medial to the superior rim of the posterior glenoid. The nerve curves around the root of the spine at the spinoglenoid notch level, approximating the glenoid rim to a distance of 2.1 cm (95% CI, 2.0-2.2). Finally, the nerve runs medially again before branching out into smaller fibers to innervate the infraspinatus muscle at a distance of 2.9 cm (95% CI, 2.7-3.1) from the inferior glenoid rim. Based on these findings, there is an approximately 2 cm–wide safe zone from the edge of the glenoid rim for the insertion of graft-fixing screws. Conclusion: When performing a subscapularis split in the arthroscopic Latarjet procedure, the risk of injuries to the musculocutaneous and axillary nerves could be reduced by aiming the switching stick inserted through the posterior portal toward the lateral edge of the intended location of the split. Injuries to the suprascapular nerve could be prevented by aiming the graft-fixing screws laterally toward the edge of the glenoid rim. Clinical Relevance: This study clarifies the location of the nerves relevant to the arthroscopic Latarjet technique and provides anatomic information that could help the surgeon reduce the risk of injuries to the musculocutaneous, axillary, and suprascapular nerves.

Les atteintes du nerf axillaire en pathologie du sport

The quadrilateral space syndrome described in 1983 is rare and difficult to recognize. Occurring in young athletes, this shoulder syndrome starts with poorly localized pain associated with poorly defined paresthesia. The symptoms are aggravated by abduction and external rotation of the upper limb. The physical examination provides little information other than a painful quadrilateral space at palpation. The standard x-ray is normal. MRI is the gold standard for a clinically suspected syndrome. The diagnosis is confirmed by EMG that shows signs of axillary neuropathy affecting the deltoid and teres minor muscles. A perfectly normal EMG does not however exclude the diagnosis. Conservative treatment is the rule: adapted movements and analytical rehabilitation. Surgery may be necessary to free an entrapped nerve.

A theoretical alternative intraosseous infusion site in severely hypovolemic children.

BackgroundStudies have shown that the venous system tends to collapse during hypovolemic shock. The use of the bone marrow space for infusions is an effective alternative, with the tibial insertion site being the norm.ObjectivesThis study was conducted to determine a quick intraosseous infusion method that could be an alternative to the tibial route in neonates during emergency situations.MethodA sample of 30 neonatal cadavers was dissected to explore a possible alternative to the tibial insertion site. The needle was inserted in the superolateral aspect of the humerus. The needle infusion site was then dissected to determine possible muscular and neurovascular damage that might occur during the administration of this procedure, with the greatest concern being the posterior circumflex humeral artery and axillary nerve exiting the quadrangular space. The distance of the needle insertion site was measured in relation to the soft tissue as well as to bony landmarks.ResultsThe calculated 95% confidence interval shows that the needle can be safely inserted into the intraosseous tissue at the greater tubercle of the humerus 9.5 mm – 11.1 mm from the acromion. This is about a little finger’s width from the acromioclavicular joint.ConclusionAnatomically, the described site is suggested to offer a safe alternative access point for emergency infusion in severely hypovolemic newborns and infants, without the risk of damage to any anatomical structures.