Proximity of Axillary Nerve During Cortical Button Repair of Pectoralis Major Tendon Rupture.

BACKGROUND: Rupture of the pectoralis major (PM) tendon is a rare but severe injury. Several techniques have been described for PM fixation, including a transosseus technique, placing cortical buttons at the superior, middle and inferior PM tendon insertion points. The present cadaveric study investigates the proximity of the posterior branch of the axillary nerve to the drill positions for transosseus PM tendon repair. METHODS: Twelve cadaveric shoulders were used. The axillary nerve was marked during a preparatory dissection. Drills were passed through the humerus at the superior, middle and inferior insertions of the PM tendon and the drill bits were left in situ. The distance between these and each axillary nerve was measured using computed tomography. RESULTS: The superior drill position was in closest proximity to the axillary nerve (three-dimensional distance range 0-18.01 mm, mean 10.74 mm, 95% confidence interval 7.24 mm to 14.24 mm). The middle PM insertion point was also very close to the nerve. CONCLUSIONS: Caution should be used when performing bicortical drilling of the humerus, especially when drilling at the superior border of the PM insertion. We describe 'safe' and 'danger' zones for the positioning of cortical buttons through the humerus reflecting the risk posed to the axillary nerve.

The management of periorbital fat excess in haemangioma involution.

Haemangioma of infancy is a common birthmark. As spontaneous involution is the rule, it is usually treated conservatively. Periorbital haemangiomata may require intervention if symptomatic and this may be early or late, where plastic surgery may be required. It has not previously been recognised that deep periorbital lesions may lead to a baggy appearance of the eyelids because of excess fatty tissue. The management of this condition is described in different clinical presentations illustrated by three female patients with a history of infantile periorbital haemangioma. Two were treated by blepharoplasty, during which an excess of fatty tissue was found, deep to the orbital septum. Birthmark stigmata were eradicated and symmetry was achieved.

Some possible codes for encrypting data in DNA.

Three codes are reported for storing written information in DNA. We refer to these codes as the Huffman code, the comma code and the alternating code. The Huffman code was devised using Huffman's algorithm for constructing economical codes. The comma code uses a single base to punctuate the message, creating an automatic reading frame and DNA which is obviously artificial. The alternating code comprises an alternating sequence of purines and pyrimidines, again creating DNA that is clearly artificial. The Huffman code would be useful for routine, short-term storage purposes, supposing--not unrealistically--that very fast methods for assembling and sequencing large pieces of DNA can be developed. The other two codes would be better suited to archiving data over long periods of time (hundreds to thousands of years).