Disclosed is a sustained release system that includes a polymer and a prodrug having a solubility less than about 1 mgml dispersed in the polymer. A method of manufacturing a betatron structure, including: fabricating two or more pieces; positioning an injector on one of the two or more pieces; and bonding the two or more pieces such that when bonded, the substrates form a hollow donut-shaped chamber. The docking station is designed to provide electrical and mechanical connection of AC power and communication devices to the portable electronic device. The stem is capable of being slidably received within the aperture of the compression member while the locking member is capable of being received within an aperture of the bone plate.