The eccentric load on the patellar tendon during a volleyball landing

Think of a volleyball landing as a high-speed collision your knees have to negotiate. When you hit the floor, your quads are desperately trying to brake, but the impact is stretching them out at the same time.

This is the eccentric load—a mechanical paradox where the muscle acts like a winch being pulled the wrong way. The patellar tendon is the cable caught in the middle, suddenly absorbing forces several times your body weight.

It’s a brutal game of physics. You’re asking a small strip of tissue to stop a falling human projectile before the pulleys in your legs snap.

Wait, what actually happens if that "cable" finally snaps?

If that cable gives way, it is a total system failure. Imagine a heavy-duty rubber band snapping under maximum tension; the kneecap, no longer anchored to your shin, gets yanked upward toward your hip by the contracting quad muscle.

You lose the ability to straighten your leg entirely. It is like the brakes on a truck failing while the engine is still revving—the mechanical link is gone, leaving the whole limb structurally useless until a surgeon can bolt it back together.

So what kind of 'bolts' are we talking about for a human knee?

We’re talking actual hardware. Surgeons use 'suture anchors'—essentially tiny, threaded screws made of titanium or bio-plastic that they drill directly into your shin bone to create a fresh mounting point.

They then weave high-tension, industrial-strength thread through the shredded end of the tendon, winching the kneecap back down from your hip and lashing it to those new bone-bolts.

It’s a literal construction site under your skin. For months, your ability to walk depends entirely on the tensile strength of those threads while your body slowly tries to 'weld' the living tissue back onto the frame.

Does that metal hardware stay inside your leg forever?

Most of the time, you’re officially a cyborg for life. Unless those screws start causing a "rattle" or irritating the surrounding tissue, surgeons generally prefer to leave them buried. Re-opening the site just to reclaim a few grams of metal is usually considered a bad investment for your recovery timeline.

If your surgeon used bio-plastic anchors, your body eventually absorbs them, replacing the "bolt" with fresh bone. But those titanium ones? They become permanent residents. Your bone eventually grows around them, treating the metal like a natural part of the landscape, much like a tree trunk slowly swallowing a wire fence.

But how do you even remove it once the bone grows over?

Pretty much. Once the bone has "osseointegrated"—basically fused—with the titanium, that screw is officially part of your chassis.

Trying to back it out later is like trying to remove a rusted bolt from an old truck frame. You risk cracking the bone you were trying to save just to get the hardware out.

If a surgeon must remove it, they have to chisel away the new bone growth first. It’s a messy demolition job that leaves a structural hole, so most just let the tree keep the fence.