Final answer:
The patient exhibits signs of a severe spinal cord injury, suggesting cauda equina syndrome, which is a medical emergency that often requires surgical intervention.
Step-by-step explanation:
The symptoms described in the question - fall from a ladder with persistent back pain, inability to void, bilateral leg weakness, and decreased pinprick sensation in the sacral and perianal area - suggest a severe spinal cord injury, which could possibly be a cauda equina syndrome (CES). CES is a neurological emergency where there is a compression of the cauda equina, the nerve roots at the lower end of the spinal cord. This condition requires immediate medical attention, often surgical decompression, to preserve lower extremity function, bowel, and bladder control.
The physical findings such as the inability to void, and bilateral leg weakness emphasize the significance of the injury's location in the lumbar region, where nerves controlling the lower extremities and bladder are located. Immediate assessment by a medical professional is critical. Diagnostic imaging, usually an MRI, would be necessary to confirm the diagnosis and ascertain the extent of the injury.