An accessory is provided for use in the conduct of patella reconstruction surgery. The accessory comprises an elongate datum limb for abutment in use with the superior pole of a patella preferably through the skin. An elongate guide limb for abutment by a side edge of a patella extends transversely relative to the datum limb has guide holes passing through it or an insert carried by it at positions selected to direct a drill or other surgical tool at an edge of the patella to enable holes or tunnels to be formed in the patella at required positions for the attachment or reception of reconstructive ligaments to the patella. Attachment limbs enable the accessory to be secured in an operative position relative to a patella. There may be slots formed by anchor bars integral with the guide limb and attachment limb to strap the accessory to a patient's knee.
