Disc degeneration and herniation are common problems leading to surgery to remove part or all of the protruding disc. But back and leg pain from disc problems can come back after surgery. The question is: where’s the pain coming from? Is it the same disc, scar tissue formed after the disc removal, a new disc herniation, or something else?
Recurrent lumbar disc herniation occurs in anywhere from five to 15 per cent of patients. So patients with back and leg pain that goes away after disc removal (a procedure called discectomy) but comes back six months (or more) later are faced with the decision about what to do.
If it’s scar tissue, more surgery isn’t going to help. Another procedure could just cause even more scar tissue. But if only part of the disc was removed and now the rest of it has herniated, then a second surgery might be needed. Disc reherniation doesn’t happen with total discectomy because the entire disc has already been removed. In the case of recurrent back pain accompanied by sciatica (pain down the back of the leg) after total discectomy, there may be another disc that is starting to herniate.
How can the surgeon tell what’s going on? There are a number of different factors that must be considered. The first is the type of surgical technique used to remove the first disc. There are several different ways to perform a discectomy.
The surgeon may use minimally invasive methods such as microdiscectomy. A small incision is made and the damaged portion of the disc is removed. A microscope helps magnify the disc so the surgeon can see the area clearly.
Another surgical technique is the endoscopic discectomy. This is another minimally invasive procedure. The surgeon uses an endoscope, which is a tube through which instruments can be passed to remove the damaged portions of the disc. The surgeon can see on a video screen as the disc is removed.
Sometimes surgeons combine parts of both procedures to perform what’s called a hybridization of techniques. The goal is to avoid bleeding and soft tissue damage while removing the offending disc. The hope is to reduce hospital time, use of narcotic (pain) medications, and get the patient back to work as soon as possible.
The use of imaging studies is another way surgeons have to diagnose recurrent disc herniation. Simple X-rays don’t show discs but they can help rule out other possible causes of back pain and sciatica such as fractures, spinal instability, or stenosis (narrowing of the spinal canal).
MRIs help show the difference between abscess, scar tissue, hematoma (pocket of blood), and disc herniation. Lab testing of blood also helps the surgeon tell if the new pain might be coming from infection.
Once an accurate diagnosis has been made, then the patient and surgeon can get down to the business of treatment. Conservative (nonoperative) care is almost always tried first. There’s no sense in doing another surgery if antiinflammatory medication, physical therapy, or steroid injection would take care of the painful symptoms.
Not everyone responds to conservative care. There are some patients who don’t get pain relief no matter what is done. The effect on their quality of life and ability to work is such that a second surgery to remove the rest of the offending disc can’t be avoided. Anyone with pressure on the nerves causing bowel and bladder changes is a candidate for surgery right away.
For those patients with spinal instability (the vertebrae are shifting back and forth or collapsing), surgery to fuse the segment may be indicated. This type of situation is most likely to develop in patients who have already had more than one disc herniation. The surgeon does what is needed to take pressure off the spinal nerve roots and then uses metal plates, screws, and bone graft material to fuse the segments together.
What’s the result of surgery for recurrent disc herniations? Is there a way to get better outcomes and avoid further disc herniation? Studies show good-to-excellent results after second surgeies in 70 per cent of patients who have just sciatica (leg but no back pain). Results are slightly better (80 per cent effective) for patients with both back and leg pain).
As with any surgery (whether it’s the first discectomy or a revision procedure), complications are a possibility. The more cutting that’s done on the surrounding soft tissues (muscles, ligaments, connective tissue), the greater the risk of infection.
Second surgeries are more likely to result in tears of the dura (lining around the spinal cord and spinal nerve roots). And, of course, the risk of scar tissue formation is much greater after a second surgery.
With at least 200,000 lumbar discectomies done every year for back pain and sciatica, improved surgical techniques and results are needed. Studies done so far have been fairly limited. Comparing one study to another is a challenge because so many different surgeons use hybridization techniques that aren’t the same from patient-to-patient or study-to-study.
Future studies are needed to identify patients who will respond the best to each type of procedure available. Less invasive techniques may eventually make it possible to reduce complications (including disc reherniation) and eliminate the need for second surgeries.