Navigation of short-stem implants.

Short-stem prostheses with modular necks were implanted using a modified Watson-Jones approach in 55 cases from November 2004 to May 2006. Twenty-eight cases were navigated using the OrthoPilot navigation system (B. Braun Aesculap, Tuttlingen, Germany). Primary stability, ease of minimal invasive implantation, and restoration of the biomechanics were evaluated. Short-term results showed a good functional outcome and a low complication rate without any dislocations. Apart from cup navigation, the navigation system helps to restore biomechanics in terms of center of rotation, leg length, and offset by advising surgeons on the modular neck offering best fit predicting the safe range of motion (ROM) reliably.