Update on Spinal Fusion
Spinal problems, in particular low back pain (LBP), remain an extremely common cause of presentation to doctors, physios and an abundance of allied health professionals.
The overwhelming majority are self-limiting and settle readily with simple techniques such as analgesia, rest and exercise aimed primarily at core strengthening – think Pilates and swimming for starters.
Our ability to diagnose, investigate and treat has increased exponentially in the last 30 years. With this there has been a 200% increase in the rate of fusion surgery.
We are now better informed surgeons and patients, and have a better understanding of long term outcomes.
Think CT scan or MRI for starters and how prevalent they are. With this comes a certain degree of patient anxiety. Not all findings on radiology are pathological. Indeed, about 40% of radiological findings are incidental and not problematic at all.
Remember the old axiom… “Treat the patient, not the X-ray”.
Nevertheless as a surgeon, one tends to see a skewed population - those that have not improved or may be worsening. The majority of patients may merely require a simple decompression - a laminectomy or discectomy. But in some instances, they need more, such as a fusion or stabilisation.
Aims of Surgery
- Nerve decompression
- Pain relief
- Stabilisation - preserve and restore sagittal and coronal balance
As an Orthopaedic surgeon, I tend to see patients who are unstable and do need a fusion. Yet in the majority, the main aim is nerve decompression, with stabilisation as “housekeeping” to ensure the problem does not recur.
E.g. It is common to see people age over 60 with years of manageable back pain but they now have developed claudicant leg pain.
The radiology shows a stenosis with a spondylolisthesis.
The main surgery is decompression, with stabilisation (fusion) in addition.
Indications to fuse
- Spondylolisthesis
- Scoliosis
- Facet joint disruption
- Multilevel decompression
- Large recurrent disc protrusion
Techniques of Fusion
- Posterior
- Anterior
- minimal disruption to muscles and nerves
- Complete discectomy, larger implants, high fusion rate
- Les adjacent segment disease ( ASD )
- Lateral
- Minimally Invasive ( MIS )
- Great for L2 – L5
- less ASD
- Combination
All techniques have pros and cons. It is a matter of which approach best treats the pathology. With modern techniques, there is an increased fusion rate and hopefully a quicker recovery.
Controversies
- Cost
- Aging population who expect treatment
- Patient expectations v realistic goals
- Osteoporosis
With much of spinal surgery, you can improve, but not cure. There is still an assumption that it is high risk, low reward!
Remember, the majority of surgery is aimed at nerve decompression.
Osteoporosis is a challenge, particularly when attempting to achieve rigid fixation.
Better implant design, improved materials (3D printed) and bone graft substitutes are all aimed at aiding in this pursuit.
Assistive technologies
These help in:
- pedicle screw placement - valuable in revision cases
- potentially more rapid screw placement
- aid in pre-operative planning
- will become standard of care, as the focus on outcomes and value come to the fore (driven by government and insurers)
- better bone graft materials, resulting in less morbidity by avoiding iliac crest bone grafting
Certainly today more surgery occurs with broader indications in older patients. There are many more revision cases as the population ages - think ASD.
Overall, the literature would suggest that the rate of significant ASD over a 10 year period postop, bad enough to require further surgery is about 10%. This tends to be in older patients, having undergone multiple procedures and long fusions.
Despite newer technologies and techniques, the fundamental aims of surgery have not changed. They are an adjunct to try and ensure safe and useful surgical outcomes.
Dr Geoffrey Rosenberg
Orthopaedics – Spine
South Coast Orthopaedics
70-72 Bridge Street
NOWRA NSW 2541
P: 02 9588 6399