Buffer for a human joint and method of arthroscopically inserting

A buffer for placement between a human's femur and tibia, the buffer comprising:

• an outer sack formed of a pliable material and having a one-way valve;
• a generally circularly shaped inner ring received within the outer sack, the inner ring
• including
• a generally vertically-oriented outer surface along the circumference of the ring, said outer surface having a top end and a bottom end,
• a generally horizontally-oriented top surface extending downwardly from the top end of the outer surface, and
• a generally horizontally-oriented bottom surface extending upwardly from the bottom end of the outer surface,
• wherein the top surface and the bottom surface are angled inwardly with respect to each other, such that the ring is generally concave;
• and
• a friction reducing fluid received within the outer sack via the one-way valve,
• said apparatus configured for insertion between the femur and tibia so as to at least partially prevent the bones from contacting each other.