In an earlier post, I reviewed the problems with lead poisoning that can occur if a bullet remains in contact with a joint space / synovial fluid, or ends up in the GI tract. But what about if it comes to rest in an intervertebral joint space? They’re dry, right?
The first case report I could find dates back to 1981. A male presented to Parkland Memorial Hospital 12 years after a gunshot to the abdomen in which the bullet lodged in a disk space. He was treated for a GI bleed, but was also noted to have many signs and symptoms of high lead levels. These included irritability, anemia, headache, lethargy, muscle weakness and confusion. A blue line was noted on the gums. X-ray of the lumbar spine showed the bullet fragment in the center of the disk space, and a cystic mass in the prevertebral area that appeared radiodense as well. Blood lead levels were elevated. The patient underwent diskectomy, resection of the mass, chelation therapy, and recovered.
Another case report from 2010 was similar in many ways. The patient was young, had a gunshot 5 years previously, and presented with symptoms of lead poisoning. The appearance of the bullet in the disk space was similar to the last case, in that the bullet could be seen within it, and there appeared to be additional radiopaque material surrounding it. It almost looked like lead was flowing out of the bullet into the disk. This case was also treated with surgical removal and chelation with a successful result.
A literature review was conducted 15 years ago that examined other case reports of bullets in the spine. Over a 25-year period 238 patients were identified with this injury. Only 12 had bullets or fragments in the disk space. All were tested for plumbism, and only one was positive. He underwent diskectomy and resection with resolution of the high lead levels.
Bottom line: We know that a bullet in contact with synovial fluid is bad, with rapid leaching of lead into the circulation. There are also suggestions that lead in contact with CSF can cause a similar problem. However, the intervertebral disk space is usually considered to be “dry” and doesn’t usually cause a problem.
However, patients with a bullet in this location should be cautioned that they do have a small risk of developing lead poisoning. They should be tested about six months post-injury to see if lead levels are on the rise. They should also be cautioned to report the development of new back pain. Structural disruption by the bullet may slowly lead to anatomic changes that result in chronic pain. And be very suspicious if there is radiopaque material in the disk space in addition to the bullet itself!
References:
- Acute lead intoxication from a bullet in the intervertebral disk space. JBJS 63A(7):1180-1182, 1981.
- Lead Poisoning by Intradiscal Firearm Bullet. Spine 35(4):E140-E143, 2010.
- Long-Term Clinical Manifestations of Retained Bullet
Fragments Within the Intervertebral Disk Space. J Spinal Disord Tech 17(2):108-111, 2004.
