Metal (titanium, cobalt‑chrome) is still the workhorse — strong, durable, and proven. But plastic (polyethylene) is the fastest‑growing material, because it's lighter and allows more natural motion. The US orthopedic devices market forecast shows that plastic components are growing at 5% annually, driven by improved wear resistance (vitamin‑E infused polyethylene). Ceramic bearings (alumina, zirconia) are used in young, active patients — they're hard and smooth, but can crack if dropped during surgery.

What's next? Biodegradable materials — implants that dissolve after they've done their job. Think: screws for ACL grafts that disappear after 12 months, so you don't need a second surgery. The US orthopedic devices market analysis notes that biodegradable materials are still niche, but growing fast, especially in paediatric and trauma applications.

But no material is perfect. Metal ions can cause allergic reactions or pseudotumours. Plastic wears out eventually. Ceramics can shatter. Biodegradables may degrade too fast or cause inflammation.

The takeaway: your surgeon should explain the pros and cons of each material. Don't just ask which is best? — ask which is best for me?