US Patent 7192431 Cartilage grafting

A set of surgical instruments for repairing a cartilage surface on a posterior surface of the patella includes a first instrument and a second instrument. The first instrument includes a channel defining a longitudinal axis that extends from the channel to intersect an anterior surface of the patella. The second instrument is mountable to the first instrument and includes a surface that is configured to be placed against a posterior surface of the patella. The longitudinal axis of the channel is at an angle to the surface of the second instrument when the second instrument is mounted in the first instrument.