Abstract: A method is provided for annealing a polymer for an orthopaedic implant by immersing the polymer in a liquid bath.

Abstract: A tracking array for attachment to an object in a surgical environment includes tracking elements detectable by a surgical navigation system to permit tracking of the object.

Abstract: A circuit for use with a power supply coupled in a switched leg of, for example, a lighting circuit, is described. The circuit provides a low impedance near the zero crossing of the AC signal and a high impedance thereafter, thereby allowing the power supply to draw current that bypasses, for instance, a light bulb.

Abstract: A threaded intervertebral implant or cage which includes a cylindrical or tapered body made from a biocompatible metal such as titanium, or a radiolucent plastic material. The cage includes a pair of opposing, threaded arcuate contact portions oriented in the superior/inferior direction for threading, supporting engagement with the endplates of adjacent vertebrae when the cage is implanted. Additionally, the cage includes a threaded lateral side having an arcuate profile, and a medial side having a concave channel extending along the length of the cage. The channel allows two cages to be implanted in a side-by-side manner between adjacent vertebrae with the channel of a first implanted cage receiving the arcuate portions of an adjacent second cage while the second cage is implanted. In this manner, a pair of adjacent cages may be implanted very close to one another.

Abstract: A universal tracking apparatus for a surgical instrument, the tracking apparatus including a support arm and tracking array. The support arm allows position adjustment of the tracking array between a number of predefined orientations relative to the instrument which are recognizeable and registerable in the navigation system. The support arm may be coupled with multiple types of surgical instruments and used to accurately define the position of the instrument in an anatomical model generated by the navigation system. The adjustable coupling between the tracking array and the support arm allows the surgeon to determine which orientation is best suited for the surgical application and also allows the surgeon to adjust the position of the tracking array during a surgical procedure without the need to re-register the tracking apparatus.