Shoulder girdles of 20 cadavers (68–94yrs) were harvested. The anterior (ACHA) and posterior circumflex humeral arteries (PCHA) were injected with ink and the extra and intraosseous courses of the dyed vasculature dissected through the soft tissues and bone to the osteotendinous junctions of the rotator cuff. The ink injection and bone dissection method was newly developed for the study. Rates of cross-over at the osteotendinous juntion were 75% in the supraspinatus, 67% in subscapularis, 33% in infraspinatus and 20% in teres minor. The supraspinatus and subscapularis insertions were vascularised by the arcuate artery, a branch of the ACHA. The insertions of the infraspinatus and teres minor were supplied by an unnamed terminal branch of the PCHA. The insertions of the rotator cuff receive an arterial supply across their OTJ's in 50% of cases. This may explain observed rates of AVN in comminuted proximal humeral fractures. The terminal branch of the PCHA supplying the infraspinatus and teres minor insertions was named the “Posterolateral Artery”. Finally, the new method employed for this study which allowed for direct visualisation of intraosseous vasculature, will enhance our understanding of skeletal vascular anatomy and have clinical applications in orthopaedic and reconstructive surgery

The posterior midline approach used in spinal surgery has been associated with a significant rate of wound dehiscence. This study investigates anatomical study of the arterial supply of the cervical and thoracic spinal muscles and overlying skin at each vertebral level. It aimed to provide possible anatomical basis for such wound complications. A dissection and angiographic study was undertaken on 8 cadaveric neck and posterior torso from 6 embalmed and 2 fresh human cadavers. Harvested cadavers were warmed and hydrogen peroxide was injected into the major arteries. Lead oxide contrast mixture was injected in stepwise manner into the subclavian and posterior intercostal arteries of each specimen. Specimens were subsequently cross-sectioned at each vertebral level and bones elevated from the soft tissue. Radiographs were taken at each stage of this process and analysed. The cervical paraspinal muscles were supplied by the deep cervical arteries, transverse cervical arteries and vertebral arteries. The thoracic paraspinal muscles were supplied by the superior intercostal arteries, transverse cervical arteries and posterior intercostal arteries. In the thoracic region, two small vessels provide the longitudinal connection between the segmental arteries and in the cervical region, deep cervical arteries provide such connection from C3 to C6. The arterial vessels supplying the paraspinal muscles on the left and right side anastomose with each other, posterior to the spinous processes in all vertebral levels. At cervical vertebral levels, source arteries travel near the surgical field and are not routinely cauterised; Haematoma is postulated to be the cause of wound complications. At thoracic levels, source arteries travel in the surgical field and tissue ischemia is a contributing factor to wound complications, especially in operations over extensive levels. Post-operative wound complications is a multi-factorial clinical problem, the anatomical findings in this study provide possible explanations for wound dehiscence in the posterior midline approach. It is postulated that drain tubes may reduce the incidence of haematoma in the cervical level

Introduction. Precise knowledge of the Femoral Head (FH) arterial supply is critical to avoid FH avascular necrosis following open and arthroscopic intra-capsular surgical procedures about the hip. The Medial Femoral Circumflex Artery (MFCA) provides the primary FH vascular contribution. Distribution of vascular foramina at the Femoral Head-Neck Junction (FHNJ) has been reported previously using an imaginary clock face. However, no quantitative information exists on the precise Capsular Insertion (CI) and intra-capsular course of the MFCA Terminal Branches (TBs) supplying the FH. This study seeks to determine the precise anatomic location of the MFCA's TBs supplying the FH, in order to help avoid iatrogenic vascular damage during surgical intervention. Methods. In 14 fresh-frozen cadaveric hips (9 left and 5 right), we cannulated the MFCA and injected a polyurethane compound. Using a posterior approach, careful dissection of the MFCA allowed us to identify and document the extra- and intra-capsular course of the TBs penetrating the FHNJ and supplying the FH. An H-type capsulotomy provided joint access while preserving the intracapsular Retinaculum of Weitbrecht (RW), followed by circumferential capsulotomy at the acetabular margin exposing the FH. The dome of the FH was osteotomized 5 mm proximal to the Articular Border (AB) providing a flat surface for our 360° scale. Right-side equivalents were used for data processing. Results. Gross dissection revealed a constant single branch arising from the transverse MFCA penetrating the capsule at the level of the anterior-inferior neck at 177° (range 167–187°), then courses within the medial RW obliquely (elevated from the neck) to the posterior-inferior FHNJ (Figure 1). This vessel was found to have an average of 5 TBs (range 3–9) penetrating the inferior FHNJ 4 mm (range 1–7 mm) from the AB at 204° (range 145–244°; 14% . 10. /. 69. anterior; 86% . 59. /. 69. posterior). In 79% (. 11. /. 14. ) of specimens, an average of 1.5 branches (range 1–3) arising from the ascending MFCA entered the Femoral Capsular Attachment (FCA) at 244° (range 216–269°), running subsynovial through the neck, and terminating in 2 TBs (range 1–3) penetrating the inferior-posterior FHNJ 5 mm (range 3–9) from the AB at 254° (range 207–281°). The deep branch of the MFCA penetrated the FCA at 327° (range 310–335°) providing an average of 6 TBs (range 4–9) running subsynovial and within the lateral RW, finally penetrating the superior FHNJ 6 mm (range 4–9) from the AB at 339° (range 286–25°; 20%. 15/74. anterior; 80%. 59/74. posterior). Discussion and Conclusion. This study demonstrates that TBs of the MFCA penetrate the joint through the mid-substance of the capsule (from the transverse MFCA) or the FCA (from the ascending or deep MFCA). Once intra-capsular, these vessels course subsynovial or within the RW and terminate at the posterior FHNJ superiorly (from the deep MFCA) and inferiorly (from the ascending and transverse MFCA). Any surgical hip intervention should preserve the posterior FCA, and lateral and medial RW in order to preserve the FH vascular supply. These results illustrate a vascular danger zone that should be respected during surgery and can be easily interpreted with the commonly used clock face