Musculoskeletal injury from fall: The patient's history of a fall from his bed and subsequent hip pain radiating to the groin and leg, described as sharp and intermittent, suggests a musculoskeletal injury such as a strain or bruise. The normal labs and CT scans support this diagnosis, as they rule out more severe conditions like fractures or internal bleeding.

Nerve injury or neuropathy: The patient's description of a "shocking sensation" from his hip into his groin and thigh could indicate nerve involvement, possibly from the fall or another underlying condition.
Osteoarthritis or degenerative joint disease: Given the patient's age, osteoarthritis could be a contributing factor to his hip pain, especially if certain movements exacerbate the pain.
Hematoma or soft tissue injury: Although the patient denies being on blood thinners, a hematoma or soft tissue injury from the fall could still be possible, especially if the pain is localized and worsens with movement.

Hip fracture: Despite normal CT scans, a hip fracture, especially an occult fracture, must be considered, particularly in an elderly patient after a fall. Further imaging like an MRI might be necessary if suspicion remains high.
Abdominal aortic aneurysm (AAA): Although the patient denies abdominal pain and the CT scans are normal, AAA is a critical diagnosis to consider in elderly males, especially with a history of falls or unexplained pain.
Spinal cord injury or cauda equina syndrome: The patient's symptoms of shock-like sensations and the mechanism of injury could suggest a spinal cord injury, which is a medical emergency.
Intracranial hemorrhage: Given the patient's history of hitting his head, there's a risk of intracranial hemorrhage, which could be life-threatening and requires immediate attention.

Pathological fracture: If the patient has an underlying bone disease like osteoporosis or a malignancy, a pathological fracture could be a rare but possible diagnosis.
Infectious or inflammatory conditions: Conditions like osteomyelitis or septic arthritis are less likely given the acute onset and normal labs but should be considered if the patient's condition worsens or does not improve with treatment for more common conditions.