The third segment of the axillary artery (TSAA) is the main vascular supply to the muscles of the upper limb. Numerous studies have reported atypical branching patterns of the TSAA, which can complicate operative interventions involving structures supplied by this segment of the artery. Our current study evaluated a previously undescribed branching pattern in the TSAA, in which the subscapular artery gave rise to an unusual posterior humeral circumflex artery, and a second subscapular artery. In addition, a third variant was found in the origin of the thoracodorsal artery: two collateral horizontal arteries supplying the deep medial surface of the latissimus dorsi muscle. Vascular anatomical variants may affect the classical upper limb interventions requiring modification of the traditional surgical approaches. This case report aims to evaluate these variants from a clinical perspective regarding the management of upper limb trauma, axillary, breast, and muscle flap surgery.

Prior knowledge of possible variations in human anatomy is essential for basic medical and clinical training. Many surgeons can avoid uncharacteristic situations by having sources and availability of resources that document potential irregularities in human anatomy. In this case, a human cadaver is identified as having an altered origin of the posterior circumflex humeral artery (PCHA). While it usually stems from the axillary artery, this cadaver had a left-sided PCHA originating from the subscapular artery (SSA) and continuing into the quadrangular space. This irregularity of the PCHA from the SSA is not commonly discussed in the literature. Physicians and anatomists need to be fully aware of this possibility and be prepared for any unexpected differences in anatomy during procedures.

UNASSIGNED: The axillary nerve and posterior circumflex humeral artery are compressed in Quadrangular Space Syndrome (QSS), which can be treated with conservative approaches or surgical decompression in recalcitrant instances. There are no clear guidelines for determining which surgical method is optimal for treating QSS and other disorders that mirror QSS.
UNASSIGNED: The goal of this study is to grade and review past, current, and planned medicinal and surgical care modalities for QSS.
UNASSIGNED: The review protocol is registered with PROSPERO (ID: CRD42022332766). To identify recent advances in the methods/techniques of medical and surgical management of QSS, PubMed and Medline databases were searched until March 2022 for publications, including case studies, case reports, and review articles, using medical subject headings terms like quadrilateral space syndrome, surgical management, and medical management. Throughout the study, all the authors scrupulously followed a well-developed registered review process and the risk of bias in systematic reviews guidance tool. Data on proposed medical and surgical management methods/techniques were compiled, and each was analyzed based on the underlying neuro-vascular systems.
UNASSIGNED: There were 88 items found in the first search. Following applying the inclusion and exclusion criteria, 16 papers were chosen for synthesis in the review study after a thorough assessment. Three studies (conservative and advanced) focused on medical care of QSS, while 12 articles (prior, current, and newer) focused on surgical management of QSS. Only four of the 15 studies reviewed proposed different surgical approaches/techniques for surgical decompression in QSS.
UNASSIGNED: There were two regularly used surgical procedures discovered, one anterior/delto-pectoral and the other posterior/ scapular. The anterior route is more technically straightforward and can be employed for surgical QSS decompression.

Background Quadrangular space syndrome involves compression of the axillary nerve and posterior circumflex humeral artery. In a few cases, its management requires surgical decompression. The current study reviews the surgical approaches used in the decompression of neurovascular structures and presents our reflections and recommendations. Methodology In this study, four human cadavers were used for dissection of the axillae and the scapular region by the senior residents of the Department of Anatomy and Department of Orthopedics. The residents dissected the quadrangular space in the eight upper limbs using anterior and posterior surgical approaches. Results To identify the quadrangular space and secure its contents, the posterior approach was recognized as the easier and quicker method by both Anatomy and Orthopedic residents; however, it may result in increased postoperative morbidity. Although the anterior (deltopectoral) approach involves more skill, it reduces postoperative morbidity. Conclusions The anterior (deltopectoral) approach with suggested modifications can be an effective method in the surgical decompression of quadrangular space syndrome. The authors suggest more cadaveric studies to provide anatomists and surgeons with the opportunity to practice and evaluate older and newer surgical approaches.

UNASSIGNED: The purpose of this study was to investigate the blood supply of the humeral head (HH) originating from the anterior (ACHA) and posterior circumflex humeral arteries (PCHA).
UNASSIGNED: Formalin preserved specimens were used to measure ACHA length, ACHA length in the bicipital groove (BG), the length of the ascending branch of the ACHA, the penetration point of the ascending branch of the ACHA at the greater tuberosity (GT), and the penetration point of the ascending branch PCHA at the GT. Fresh specimens were used to identify the intraosseous vascular network by both the ACHA and PCHA by injecting a contrast medium using a high-resolution microfocus computed tomography. Specimens were then dissected to expose where the branches of the ACHA and PCHA penetrate the bone, and a small section of the medial head was removed to visualize dye penetration of the cancellous bone.
UNASSIGNED: Seven variations for the course of the ACHA were observed. In 36%, the ACHA runs posterior to the BG and posterior to the long head of biceps tendon, and splits into the anterolateral ascending and descending branch. The ascending branch enters the medial wall of the GT. Microfocus computed tomography demonstrated that the intraosseous branch of the ascending branch of the ACHA runs within the GT in a medial direction from its penetration point just along the lateral edge of the BG. Intraosseous accumulation of contrast within the GT supply occurs more toward the inferior aspect of the HH, and the anterior-superior and superior-medial aspect of the HH is not perfused. This region is a high-risk zone for avascular necrosis.
UNASSIGNED: The results of this study suggest that 7 variations for the course of the ACHA exist. These variations and the interruption of the intraosseous arterial network in the GT with surgery and suture anchor placement result in a high-risk zone in the superomedial aspect of the humeral head overlapping with the area where early aseptic necrosis is identified.

OBJECTIVE: Sports related aneurysmal degeneration and thrombosis of the Posterior Circumflex Humeral Artery (PCHA) has been known to cause symptoms of digital ischemia (DI) in elite volleyball players. Studies have reported symptoms of DI in as much as 28% of the elite indoor volleyball players. The purpose of this study was to determine the diagnostic value of the Shoulder PCHA Pathology and digital Ischemia - Questionnaire (SPI-Q) for detection of sports related PCHA disease using ultrasound data as the standard of reference.
METHODS: The SPI-Q was completed by elite indoor volleyball players from the highest and single highest Dutch volleyball division and by elite beach volleyball players participating in the 2014 Grand Slam Beach Tournament The Hague (GSBTH). Ultrasound assessment of the dominant shoulder was performed on-site using the SPI-US protocol. The SPI-Q sensitivity, specificity, positive - and negative predictive value and positive - and negative likelihood ratios, and the diagnostic odds ratio were calculated for detection of sports related PCHA disease, using ultrasound as the standard of reference.
RESULTS: Two hundred twenty-four elite male indoor volleyball players from the Dutch division were included in this study and 62 elite male and female beach volleyball players participating in the GSBTH: a total of 278 players. Thirty-five percent of the players reported symptoms of DI. The prevalence of PCHA disease was 6.1%. For the SPI-Q we found a sensitivity of 18% (95% CI 4-43), specificity of 64% (95% CI 58-70), positive predictive value of 3% (95% CI 0.7-8.9) and negative predictive value of 92% (95% CI 87-96), positive likelihood ratio of 0.50 (95% CI 0.18-1.40), negative likelihood ratio of 1.28 (95% CI 1.01-1.62) and a diagnostic odds ratio of 0.39 (95% CI 0.11-1.38).
CONCLUSIONS: The diagnostic value of the SPI-Q to detect PCHA disease in elite volleyball players is poor, which makes it unsuitable as a diagnostic instrument for sports related PCHA disease specifically. However, it can be used to assess all-cause symptoms of DI and raise awareness within athletes and sports physicians, which is important for preventing ischemic complications.

We investigated the anatomical features of the axillary nerve and its accompanying vessels with respect to the lateral wall of the greater tuberosity, focusing on the relationship between the neurovascular bundle and the proximal humeral locking plates. Magnetic resonance images of 30 Japanese patients\' shoulders were examined. Oblique sagittal images across the greater tuberosity and the neurovascular bundle, which contain the axillary nerve and posterior circumflex humeral artery and vein, were obtained. The distance between the superior aspect of the greater tuberosity and the superior and inferior borders of the neurovascular bundles was measured at the anterior, middle, and posterior edges of the greater tuberosity. The neurovascular bundle was 28.5-36.7 mm, 32.6-41.3 mm, and 38.1-47.5 mm distal to the superior aspect of the greater tuberosity at the anterior, middle, and posterior edges, respectively. We evaluated the relationship between the neurovascular bundle and 3 different locking plates, which were placed at the lateral aspect of the greater tuberosity. Only 3 or four locking screws at the most proximal part could be safely inserted without axillary nerve interference.

Anatomical variation of the branching pattern of axillary artery is very common. The knowledge of this variation is often useful during different surgical and interventional procedures. Variations include typically of Lateral Thoracic Artery (LTA) and Posterior Circumflex Humeral Artery (PCHA). The present case has been reported to document the variation of LTA and PCHA. The axilla of a 65-year-old embalmed female cadaver was routinely dissected for educational purpose in the Department of Anatomy, AIIMS, New Delhi, India. Cunnighams Manual of Dissection was followed during the whole dissection procedure. We found that the third part of axillary artery gave rise to a common trunk which divided into PCHA and LTA. The PCHA curved backwards around the humeral neck and made anastomosis with the anterior circumflex humeral artery. The LTA supplied serratus anterior and the pectoral muscles and made anastomosis with intercostal arteries. The axillary nerve accompanied PCHA while the thoracodorsal nerve accompanied LTA. The rare anatomical variation of the branching pattern of axillary artery is assumed to be helpful in the surgical procedures and various therapeutic interventions of the upper limb.

OBJECTIVE: To determine the prevalence of posterior circumflex humeral artery (PCHA) aneurysms and vessel characteristics of the PCHA and deep brachial artery (DBA) in elite volleyball players.
METHODS: Two-hundred and eighty players underwent standardized ultrasound assessment of the dominant arm by a vascular technologist. Assessment included determination of PCHA aneurysms (defined as segmental vessel dilatation ≥150 %), PCHA and DBA anatomy, branching pattern, vessel course and diameter.
RESULTS: The PCHA and DBA were identified in 100 % and 93 % (260/280) of cases, respectively. The prevalence of PCHA aneurysms was 4.6 % (13/280). All aneurysms were detected in proximal PCHA originating from the axillary artery (AA). The PCHA originated from the AA in 81 % of cases (228/280), and showed a curved course dorsally towards the humeral head in 93 % (211/228). The DBA originated from the AA in 73 % of cases (190/260), and showed a straight course parallel to the AA in 93 % (177/190).
CONCLUSIONS: PCHA aneurysm prevalence in elite volleyball players is high and associated with a specific branching type: a PCHA that originates from the axillary artery. Radiologists should have a high index of suspicion for this vascular overuse injury. For the first time vessel characteristics and reference values are described to facilitate ultrasound assessment.
CONCLUSIONS: • Prevalence of PCHA aneurysms is 4.6 % among elite volleyball players. • All aneurysms are in proximal PCHA that originates directly from AA. • Vessel characteristics and reference values are described to facilitate US assessment. • Mean PCHA and DBA diameters can be used as reference values. • Radiologists need a high index of suspicion for this vascular overuse injury.

Elite overhead athletes are at risk of vascular injury due to repetitive abduction and external rotation of the dominant arm. The posterior circumflex humeral artery (PCHA) is prone to degeneration, aneurysm formation, and thrombosis in elite volleyball players and baseball pitchers. The prevalence of PCHA-related thromboembolic complications is unknown in this population. However, the prevalence of symptoms associated with digital ischemia is 31% in elite volleyball players. A standardized noninvasive imaging tool will aid in early detection of PCHA injury, prevention of thromboembolic complications, and measurement reproducibility. A standardized vascular sonographic protocol for assessment of the proximal PCHA (SPI-US protocol [Shoulder PCHA Pathology and Digital Ischemia-Ultrasound protocol]) is presented.