Department of Applied Anatomy

Introduction: Achilles tendon ruptures, especially ruptures caused by pathologic conditions and also by achillotendinitis are often attributed to the alleged hypovascularisation of the Achilles tendon. Anatomic studies often mention an avascular plane. The purpose of this study was to re-investigate the arterial supply of the Achilles tendon. Material and methods: Lower legs of 28 anatomic specimen were injected with a radiologic contrast agent and subsequently an arterial angiography was performed. Afterwards the legs were embalmed and later anatomically dissected. The origin of arteries entering the paratenon of the tendo calcanei branching off from either the anterior (TA) or the posterior tibial artery (TP) was determined. The distance between the points of commencement of these nutrient arteries and a specific reference point, i.e. the insertion of the Achilles tendon into the tuber calcanei, was measured digitally on the radiographs and again with a slide-gauge on the dissected specimens. Results: As revealed by angiographic analysis, the TA gave off 5 vessels (v) at a frequency and median distance to the tuber calcanei (in cm) of v1: 50%, 6.01 cm; v2: 39.3%, 7.88 cm; v3: 35.7%, 9.71 cm; v4: 17.9%, 12.7 cm; v5: 10.7%, 14.6 cm. The TP contributed to the arterial supply of the Achilles tendon by means of 7 inserting arteries branching off at a frequency and mean distances of v1: 67. 9%, 4.53 cm; v2: 60.7%, 6.97 cm, v3: 50%, 9.58 cm; v4: 35.7%, 10.89 cm; v5: 25%, 12.65 cm; v6: 10.7%, 16.94 cm; v7: 3.6%, 18.7 cm proximal to the tuber calcanei. However, due to the small diameter of these branches, by anatomic dissection no nutrient arteries commencing from the TA could be detected. On the other hand, a maximum of 7 vessels originating from the TP, larger than the former vessels, had been also revealed by anatomic dissection (frequency and mean distances, v1: 100%, 6.8 cm; v2: 82.1%, 7.7 cm; v3: 71.4%, 9.5 cm; v4: 35.7%, 11.3 cm; v5: 17.9%, 9.9 cm; v6: 7.1, 10.5 cm; v7: 3.6%, 12.0 cm). Conclusion: A dense net of small arteries inserts into the paratenon of the Achilles tendon in its lower 20 cm. The angiographic method was more specific and showed vessels that could not be identified as arteries originating from the TA by macroscopic anatomic dissection.

The purpose of this study was to compare the gradient spin-echo (GRASE) to the fast spin-echo (FSE) implementation of fast fluid-attenuated inversion recovery (FLAIR) sequences for brain imaging. Thirty patients with high signal intensity lesions on I'*-weighted images were examined on a 1.5 T MR system. Scan time-minimized thin-section FLAIR-FSE and FLAIR-GRASE sequences were obtained and compared side by side. Image assessment criteria were lesion conspicuity, contrast between different types of normal tissue, image quality, and artifacts. In addition, contrast ratios and contrast-to-noise ratios were determined. Compared to FSE, the GRASE technique allowed a 17% reduction in scan time but conspicuity of small lesions in particular was significantly lower on FLAIR-GRASE images because of higher image noise and increased artifacts. Gray-white differentiation was slightly worse on FLAIR-GRASE. Physiological ferritin deposition appeared slightly darker on FLAIR-GRASE images and susceptibility artifacts were stronger. Fatty tissue was less bright with FLAIR-GRASE.

Even though the vascular supply of the human patella has been object of numerous studies until now, none of them has described in detail the rich arterial supply provided via the infrapatellar fat pad (of Hoffa). Therefore, we aimed to complete the knowledge about this interesting and clinically relevant topic. Five human patellae taken from voluntary body donators were studied at the Department of Applied Anatomy of the Medical University of Vienna. One was dissected under the operation microscope, a second was made translucent by Sihlers-solution, and three underwent angiography using a 3D X-ray unit. The results revealed that the patella to a considerable amount is supplied by arteries coursing through the surrounding parts of the infrapatellar fat pad. The latter were found to branch off from the medial and lateral superior and inferior genicular arteries. Within the infrapatellar fat pad, these arteries formed a dense network of anastomoses which are all contributing to the viability of the patellar bone. Due to the rich arterial supply reaching the patella via the infrapatellar fat pad, it seems advisable to preserve the fat pad during surgery of the knee in order to reduce the risk of vascular impairment of the patella.

Purpose: Arthroscopic repair of superior labral anterior to posterior (SLAP) lesions is often associated with a prolonged period of pain during the rehabilitation process. This might possibly be due to hypoxia in the biceps tendon anchor caused by sutures. The purpose of the study was to investigate the arterial supply of the long head of the biceps brachii tendon (LHBT) that may be impaired by surgery in the region of the biceps tendon anchor. Methods: On 20 human formalin-fixed bodies, the anterior circumflex humeral artery (ACHA) was located and followed into the intertubercular groove until it reached the LHBT. On 10 fresh-frozen anatomic specimens of the upper extremities, contrast medium was injected into the axillary artery, a 3D scan was performed, and multiplanar reconstructed (MPR) slices were generated. A set of maximum intensity projection (MIP) reconstructions from 10 computed tomography angiographies (CTA) of the upper extremities was used to confirm the findings of the 3D scan. Results: All anatomical dissections and radiological investigations revealed that the proximal portion of the LHBT was consistently supplied by an ascending branch of the ACHA. No artery was found to supply the biceps tendon anchor from the proximal aspect. Conclusions: As the arterial supply of the LHBT is mainly provided by the ACHA, which enters the glenohumeral joint from the distal aspect, surgery at the bony origin of the LHBT may not interfere with this specific vessel.