Knee Gel Injections for Arthritic Knees
The form says "knee gel injections." The name sounds simple, and the details are left off the page.
This page translates the phrase, names the source of the definition, and separates what the name describes from what it promises. It is written for readers in East Rutherford and across the Meadowlands who have the term in front of them and want it in plain words.
What the name means
Cleveland Clinic explains it directly: "Knee gel injections are injections of hyaluronic acid, a viscous substance found naturally in your joints." So the gel in the name is hyaluronic acid, and the injection goes into the knee. The Cleveland Clinic page on knee osteoarthritis covers the condition the procedure is named alongside.

What the term describes
It describes a material and a purpose. The material is hyaluronic acid. The purpose, in Cleveland Clinic's words, is this: "Gel injections can help replace the lost lubrication in your knee joint when you have arthritis." The sentence is tied to a condition, arthritis, and to a single joint, the knee.
What it does not promise
Look at the verb again. "Can help replace" is a statement of what the injection is able to do. It is not a result you are owed, and it does not say how much lubrication returns or for whom. A brand-sounding procedure name is still a label, and the label stays silent on your outcome.
A different injection, a different entry
Paperwork about the knee may also list steroid injections. That is a separate term with its own definition, so read the Cleveland Clinic overview of cortisone shots as its own page rather than blending the two.
The question to ask
Ask your provider: given what is wrong with my knee, what is this gel meant to change, and how will we know if it did? That question holds the term to its own definition.