The coracoid process is supplied by a direct branch of the 2nd part of the axillary artery permitting use of the coracoid as a vascularised bone flap, and improving it's viability in Latarjet or Bristow procedures.

BACKGROUND: A comprehensive understanding of the anatomy of the vascular supply of the coracoid is needed to ensure that the coracoid remains vascularised in order to optimize bone union during any coracoid transfer procedures. It is the purpose of this study to present an anatomical overview of the blood supply of the coracoid process, describing a previously unidentified vessel that arises directly from the axillary artery and nourishes the coracoid process, permitting the coracoid to be used as a free bone flap. METHODS: An anatomical study examining the blood supply to the coracoid process of the scapula was performed in 14 shoulders from 7 fresh frozen (unembalmed) adult cadavers. In addition, the vascular supply to the coracoid was studied in 22 shoulders in patients during operations around the anterior shoulder. RESULTS: In all the cadaveric shoulders studied there was a single consistent direct branch of the second part of the axillary artery that supplied the distal 2-3 cm of the coracoid process with a corresponding vein. The mean pedicle length for the artery was 4.46 cm (range 3.1-5.6 cm). This artery originated from the axillary artery from the antero-lateral position in 6, lateral position in 3 and posterolateral position in 5 shoulders. The mean pedicle length for the vein was 5.8 cm (range 4.5-7.8 cm). The vein joined directly to the axillary vein in 3 shoulders and via another tributary (parallel to the axillary vein) in 9 shoulders. The diameter of the artery and vein averaged 1-1.5 mm. The clinical study confirmed the findings of the cadaveric study. CONCLUSION: Our anatomical cadaveric and clinical studies demonstrate the presence of a previously unidentified direct arterial branch from the second part of the axillary artery supplying the anterior 2-3 cm of the coracoid process of the scapula. This consistent vessel and accompanying vein should be preserved for any surgical procedure that involves transfer of the coracoid process, such as the Laterjet and Bristow procedures for shoulder dislocation and can be used for free transfer of the coracoid where a small vascularised bone flap may be required.

A fluorescence-based method for measuring nitric oxide in extracts of skeletal muscle.

We describe here a fluorescence assay for nitric oxide synthase activity in skeletal muscle based on a new indicator, 4,5-diaminofluorescein (DAF-2). The rapid and irreversible binding of DAF-2 to oxidized NO allows real-time measurement of NO production. The method is safer and more convenient than the usual citrulline radioassay and can be used with crude muscle extracts. Rabbit fast tibialis anterior (TA) muscle had a nitric oxide synthase (NOS) activity of 44.3 +/- 3.5 pmol/min/mg muscle. Addition of NOS blocker N(G)-allyl-L-arginine reduced this activity by 43%. Slow soleus muscle displayed NOS activity of 7.3 +/- 2.5 pmol/min/mg muscle, 16% that of the TA muscle. Continuous stimulation of TA muscle at 10 Hz for 3 weeks reduced NOS activity by 47% to an intermediate value consistent with the associated conversion of the muscle phenotype from fast to slow.