Final answer:
The subject of this question is about a medical incident during a back operation involving the breakage of an instrument in the patient's spinal canal.
Step-by-step explanation:
In this case, the subject matter is a medical incident involving a patient undergoing a back operation. The incident involves the breakage of a forceps-like instrument in the patient's spinal canal, raising concerns about potential complications and the standard of care provided during the surgery. This falls within the field of medicine and specifically the area of surgical procedures and patient safety.