When a hip joint affects quality of life by restricting movement and causing chronic pain, many people decide to have an artificial joint implanted. Total joint replacement surgery, including hip replacement, is one of the most performed elective surgeries. According to the American Academy of Orthopaedic Surgeons (AAOS), more than 450,000 total hip replacement surgeries are done yearly in the U.S., and this number is expected to reach 635,000 surgeries annually by 2030. Here are five things to know about machining hip components:

1. Artificial hip joints must be manufactured with high precision.

This is most important where the hip stem and the joint ball connect. For the conical surfaces to fit together perfectly, they need to be produced with the highest precision and surface quality. The CERATIZIT machining solutions for this precise operation are the KOMtronic U-Axis and stepped reamer. These and other precision tools ensure all required tolerances are met while increasing productivity compared to conventional production methods.

2. Tool choice plays a crucial role when manufacturing these components.

Artificial hip joints consist of difficult-to-machine materials which need to be machined within the narrowest tolerances and as economically as possible. Ultimately, an artificial hip replacement of the highest quality should be available to as many people as possible. We work with great dedication to find suitable tool solutions for these tasks.

3. Artificial hip joints have demanding and varied requirements. For the hip stem, made from high-strength titanium alloy Ti6Al4V, an angle tolerance of ±5° must be maintained in the conical connection area. Other tolerances are 3µm for straightness, 8µm for roundness, and 60µm for the diameter. It’s also important to achieve the specified contact ratio for the cone and produce a precisely defined groove profile.

4. The joint ball is made from a cobalt-based alloy (Co-Cr-Mo). Its conical hole must have the same shape, angle, and dimension tolerances, as well as the specified contact ratio. No unintended marks, ridges, or grooves can be made during machining.

5. To produce the conical outside profile, opt for pre-machining with a solid carbide conical milling cutter. The subsequent roughing and finishing are performed using the U-Axis system. This is an interchangeable, freely programmable NC axis for machining centers that can machine contours and be used for turning.

CERATIZIT’s Team Cutting Tools Part of CERATIZIT Group’s Team Cutting Tools, along with Cutting Solutions by CERATIZIT, WNT, and KLENK, KOMET brand tooling is a trusted partner in the medical industry. The freely programmable KOMTronic U-Axis systems enable any contour and turning machining on non-rotationally symmetrical parts.