While I have seen a few patients in my career who really, desperately needed a low back fusion, they have been very few and very far between. Yet this type of surgery, where the low back bones are fused together with surgically implanted hardware, has become increasingly commonplace. While a whole slew of complications for this hyperinvasive procedure have been reported, we now have a brand-new one. Turns out that fusing the low back reduces the effectiveness of hip replacement surgery. Who knew?
Why Fusion Is Mostly a Dumb Idea
The idea behind spinal fusion is simple. Since spinal segments (the shock absorber disc and facet joints) can get sloppy when they degenerate, we need to provide stability again by fusing it all together. There’s just one little problem. Fusing something that was meant to move just transfers forces to the segments above and below. This can then cause these levels to degenerate, leading to the need for another fusion! The video below explains this concept of adjacent segment disease:
Why Then Are Spine Fusion Surgery Rates Skyrocketing?
Anytime you can get a cheap and quick FDA approval for a piece of surgical hardware that retails for thousands of dollars that can be made in China for tens of dollars, it’s not hard to see that the profit calculus is extremely favorable. So it’s therefore not surprising that these device companies can afford armies of sales reps to push these devices and a slew of “influencer” physicians who can write articles extolling the virtues of fusion. Add to that a reimbursement from insurance companies that’s many times higher than just taking out a piece of lumbar disc or a bone spur, and you get a fusion epidemic.
The Kinetic Chain
Your body is one connected machine with specialized parts. Perhaps one of the biggest disservices that the orthopedic community has created is the idea that the body is made up of separate parts. For example, we have the “knee guy” (or gal), the “hip specialist,” and the “foot and ankle expert.” The problem is that in reality there is no such thing as a knee, hip, or ankle—in that these don’t exist in isolation. Instead, there is a machine designed to transfer forces from the spine (trunk) to the ground through the leg. So what happens at the ankle impacts the knee and hip and spine and vice versa. The problem is that all of this is complex, and it can be difficult for physicians to understand and even more challenging to teach. Hence, few physicians understand it with any level of sophistication.
The New Low Back Fusion and Hip Replacement Study
The researchers in this new study looked at 82 patients who had spinal fusion before their hip replacement and 82 matched control patients without spinal fusion. Patients without spinal fusion had improved outcomes when compared to their counterparts with spinal fusion. This was observed in their six-month and two-year functional scores (WOMAC and/or SF-36).
The upshot? Robert Heinlein once said that war was the last resort of the incompetent. What he was trying to relay through some hyperbole was that war is awful and that we should do everything we can to prevent it. In the same way, spinal fusion is the last resort of the incompetent physician. It’s an awful surgery, and we should do everything we can to prevent it. More specifically, if you have a hip replacement planned, you may want to think twice if you also have had a low back fusion! If you haven’t yet had your low back fused, then here’s another reason not to get the surgery!