In 2016, Desai et al published the results of their randomized, multi-center clinical trial which compared the results of conservative care against conservative care with the addition of intradiscal biacuplasty, for the treatment of MRI and discography-confirmed discogenic pain.
STUDY DESIGN: using very strict entry criteria (perhaps a little too strict) the team performed provocative discography on 297 patients, all of whom had been tentatively diagnosed with discogenic pain (i.e., low back and/or leg pain secondary to a symptomatic annular tear within the disc).
Of that large group, only 63 patients met the stringent inclusion/exclusion criteria and were enrolled in the study. Next, these patients were randomly assigned into either a conservative care group (n=34) or a conservative care + intradiscal biacuplasty (n=29) and then followed closely for (only) six months.
Just before they started treatment, at three months, and again at six months, all patients completed a battery of outcome assessment questionnaires, including a visual analog pain scale (VAS), the Oswestry disability index (ODI) and the physical functioning component of the short form SF-36 (SF-36). Careful, medication usage records were also kept with regard to the amount of daily opioid consumption. There was no patient satisfaction questionnaire, return to work comparison, or minimally clinically important difference assessment, which was quite unfortunate. Furthermore, there is no follow-up beyond six months.
With regard to the VAS, which was the “primary outcome assessment,” patients in the conservative care + biacuplasty group had a significantly greater drop in the mean VAS score (in other words, they improved more), compared to the conservative care alone group (P=0.02). The authors also looked at patients who obtained ≥ 50% improvement on VAS at six months and discovered that only 7% of the conservative care group reach this level, compared to 42% in the biacuplasty group (P=0.0013).
However, with regard to patient functional disability as demonstrated on the ODI and SF-36, there was no significant difference between the groups with regard to improvement. Furthermore, when they evaluated the opioid usage data, they also found no significant difference between the groups.
So, it seems fair to say that biacuplasty has about a 40% chance that decreasing your pain by 50% within six months. Not an earth shattering outcome!
First of all, I must applaud the authors' effort for designing and pulling off this complex multi-center randomized controlled trial, which is not easy to do.
That said, I was very disappointed that the patients were not followed for the “industry standard” of two years; six months is not nearly enough time to assess the efficacy (efficacy = safety and effectiveness) of any treatment intervention! In fact, I’m not even sure how they got published in SPINE, one of the top spine journals in the world (at least it used to be?) which I know from personal experience is very picky about that two-year mark. Hopefully, they will continue to report outcomes further on down the road.
Secondly, I am very disappointed with the results. Although at first blush I was once hopeful (i.e., based on the randomized placebo-controlled trial results of Kapural et al.) that we finally had a decent intervention for the treatment of chronic discogenic pain, my hopes are now somewhat dashed. I mean these results demonstrate that only 42% of the patients with single-level discogenic pain got 50% pain reduction, as measured at the six-month time point. Those are not very promising numbers! Furthermore, with regard to functional disability (the ability of the patient to participate in life), there is no difference between the groups, as measured by the ODI, the SF-36, or opioid pain medication usage.And let's not forget that only single-level symptomatic discs were allowed in the study. It's not uncommon for a patient to have two or even three levels of involvement. Intuitively, it would seem that there's even less of a chance for these multilevel involvement patients.
And what will the long-term consequences be for poking a hole in both sides of the disc?
Well, we know from the work of Stanford’s Eugene Carragee that a single-sided disc needle puncture has deleterious long-term effects on the health of that disc. (i.e., the stick increases the chance of symptomatic disc herniation and need for surgery). The intradiscal biacuplasty procedure calls for a “double disc needlestick” (one on each side), which can’t bode well for the future of that disc.
What would be very interesting is to follow these same patients for 10 years and see what happens to them. I hypothesize that the group which underwent the biacuplasty would have a much higher rate of interbody fusion surgery (secondary to the development of severe chronic discogenic back pain) and disability, compared to the group that only received conservative care.
How come more people didn’t improve with the intradiscal biacuplasty procedure?
I would speculate that it’s all about the “luck” of needle placement with regard to the location of the annular tear(s). Remember, the needle placement is totally blind. In other words, the doctors can’t see the annular tear during the procedure, so they’re just guessing as to their location. I bet the ones who had good outcomes (got better) also had a needle placement either in or immediately adjacent to the symptomatic annular tear. The ones who didn’t get better were not lucky enough to have either of the needles close enough to the annular tear to effectively ablate (burn) it into a non-pain generating tissue.
So, is intradiscal biacuplasty worth trying?
Well, in my opinion, if you are scheduled for an interbody fusion for the treatment of discogenic pain, then maybe intradiscal biacuplasty is worth a try as a last-itch-effort to avoid that fusion. However, if your pain and disability are not bad enough to risk having an interbody fusion, then based on the current literature and logic deduced from that literature, I would not recommend it.
BOTTOM LINE: if you have chronic disabling discogenic pain, as confirmed by MRI and provocative discography, then you’ve got less than a 50-50 chance of having your pain decreased by 50% by undergoing the intradiscal biacuplasty procedure. On the downside, based on the work of Carragee, you are most likely increasing your chances of ruining that disc secondary to double-needle-stick-induced degenerative change. Why do I say that?
Carragee followed the long term (10 year) after-effects of a single needlestick injury to the disc which demonstrated a statistically significant proportion of those discs became symptomatic (some to the point of surgery) compared to a control group. Therefore, it seems logical to conclude that the double-stick needle injury necessitated by the intradiscal biacuplasty procedure may doubles the negative effects demonstrated by Carragee.