Adjustable Knee Spacer with Screw Mechanism for Bone Loss Compensation

The spacer is divided into three separate components: the tibial component, the separator, and the bone cement layer. This segmentation allows each component to be optimized independently - the tibial component provides structural strength, the separator maintains precise distance through its rigid structure, and the bone cement provides anchorage. The separator acts as a distinct element that prevents the distance-critical function from being compromised by bone cement deformation.

The separator is pre-positioned at the correct distance from the tibial component before bone cement curing occurs. The separator's rigid structure is designed to maintain the precise distance relationship during the bone cement curing process, preventing any deformation from affecting the critical measurement. This preliminary positioning ensures that when the bone cement cures and hardens, the distance geometry is already established and protected.

The separator is designed with adjustable positioning capability relative to the tibial component, transforming the spacer from a fixed-distance device to an adjustable-distance device. The separator can be positioned at multiple discrete distances from the tibial component surface, allowing adaptation to different amounts of bone tissue loss and various anatomical geometries while maintaining a relatively simple overall structure.

The separator incorporates localized adjustment features (such as positioning ridges or adjustable mechanisms) that enable distance modification only where needed, while the rest of the spacer structure remains simple and unchanged. This allows anatomical adaptation through localized adjustment rather than requiring complete structural redesign of the entire spacer.

The separator's distance from the tibial component is made adjustable rather than fixed, allowing the spacer system to adapt to different amounts of bone tissue loss. The separator can be positioned at multiple discrete distances, providing both precise distance control for each specific case and versatility across different anatomical scenarios.

The critical parameter of separator-to-tibial-component distance is made variable rather than fixed. By enabling adjustment of this distance parameter, the spacer can be tailored to compensate for different degrees of bone tissue loss while maintaining precise control over the final distance geometry through the separator's positioning mechanisms.