Interbody Fusion: A Minimally Invasive Procedure for Spinal Problems

Patient benefits include a lower risk of affecting other parts of the body, and also a lower risk of infection due to a smaller cut.

Simply put, degenerative disc condition describes the symptoms of radiating weakness or numbness, or pain stemming from a degenerated disc in the spine. Disc degeneration is a natural part of aging, and over time everyone will exhibit greater or lesser degree of degeneration of their spinal discs.

However, not all people will develop symptoms. In fact, degenerative disc disease is quite variable in its nature and severity. While the definition sounds simple, many patients diagnosed with degenerative disc disease are left wondering exactly what this diagnosis means for them.

What is interbody fusion?

"Interbody fusion is the process where the disc between 2 vertebral bodies is removed and replaced with a cage filled with bone graft allowing the bones to fuse to each other," says Dr Benjamin Tow, an orthopaedic surgeon at Mount Elizabeth Hospital, Singapore. "It is widely used when there is a need to stabilise the spinal segment, which may be part of deformity correction, nerve root decompression or restoration of the space for the spinal nerves to exit."

Older forms of spinal fusion involve using screws to connect two vertebras, which may compromise or affect the alignment of the spine due to loss of disc height. Interbody fusion allows proper alignment of the spine as the cage keeps the disc height the same. Having a bone graft will also mean that the post-fusion vertebrae will be more stable.

Originally, interbody fusion was traditionally performed as an open surgery from the back and the abdomen. Known as Anterior Lumbar Interbody Fusion, there are risks as the surgeon will have to take nearby critical organs, arteries and muscle into consideration. These days, interbody fusion can be performed in a minimally invasive manner at lower risks to the patient.

Extreme Lateral Interbody Fusion, or XLIF, is a minimally invasive form of interbody fusion that is performed through the side of the back as opposed to the front or the back. In XLIF, a probe is inserted from the side of the back, avoiding the nerves and muscles. The probe is then used to remove the disc and insert the implant.

"Minimally invasive fusion requires a smaller incision and causes less tissue disruption with less bleeding," says Dr Tow. "This translates to less pain, faster recovery, and less risk of infection."

How long does it take to recover?

Generally, patients who undergo minimally invasive interbody fusion will only require 1 or 2 days of hospitalisation before returning home. "In short segment fusions, the patient can return to activities such as jogging, swimming and light gaming sports," Dr Tow says. "There may be aches and pains for the first few months before the fusion becomes fully established," he explains, but bending over or lifting heaving things should still be avoided until the fusion is fully established, which takes around 3 months.

There are different approaches to interbody fusion depending on the patient's condition, not all patients are suitable for minimally invasive procedures. While the benefits of minimally invasive surgeries can be attractive, the fact remains that the most suitable procedure for your condition is something that only your orthopaedic surgeon can determine. For example, people with severe spinal misalignment problems might not be able to go through XLIF as it might be difficult to access the disc from the side.

Visit your orthopaedic surgeon to understand if interbody fusion can be used to improve your back condition.