CORR Insights®: Are There Differences Between Patients with Extreme Stenosis and Non-extreme Stenosis in Terms of Pain, Function or Complications After Spinal Decompression Using a Tubular Retractor System?

Single-level tubular decompressive minimally invasive surgery (MIS) for patients with stenosis is technically demanding, and therefore, the more severe the stenosis, the greater potential for residual symptoms and loss of function because of inadequate decompression. Among spine surgeons, we have seen an increased preference for minimally invasive procedures for spinal disorders [8] because MIS of the spine has been shown to decrease length of stay, offer higher suitability for outpatient procedures, decrease blood loss, lower narcotic requirements, and lower infection rates [5]. Having said that, once outside the early convalescent period, patients-reported outcomes scores following less-invasive surgery are not much different from those after more-conventional open procedures [4, 6]. One concern I have, though, is learning curve associated withMIS [7]. In the last 15 years, I have observed increased interest in MIS, and more publications about these approaches with each passing year. However, in my observation, most of these papers are written by designers, originators of techniques, consultants, or highvolume surgeons who are well outside their learning curves with these new approaches. As these techniques gain traction in the broader practice community, we should not assume that a surgeon just learning a lessinvasive technique will be able to replicate results achieved by a designer, originator, or experienced surgeon who has hundreds or even thousands of these procedures under his or her belt. Believing otherwise (or practicing without consideration of this fact) puts patients at risk. I also am concerned by the fact that many of these studies are selective case series or historically controlled studies, which suffer heavily in some instances from selection bias (the easier procedures being done MIS, and the morechallenging ones decanted into the “control” group, if there is a control group).This is one of the strengths of the current study by Kulkarni and Das [2]; although a small number of patients in this large series were lost to follow-up, it was a genuine all-comers study, with no exclusions. It also focused on some of the more-difficult single-level procedures we see, those with extreme stenosis, and despite this, none underwent conversion to an open procedure and no alternate forms of decompression procedure were used. Having said that, it is clearly the work of surgeons experienced in this technique, and we should not assume their results will generalize to surgeons who are new to this approach, as they probably will not. This CORR Insights is a commentary on the article “Are There Differences Between Patients with Extreme Stenosis and Nonextreme Stenosis in Terms of Pain, Function or Complications After Spinal Decompression Using a Tubular Retractor System?” by Kulkarni and Das available at:DOI: 10.1097/CORR.0000000000001004. The author certifies that neither he, nor any members of his immediate family, have any commercial associations (such as consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article. The opinions expressed are those of the writer, and do not reflect the opinion or policy of CORR or The Association of Bone and Joint Surgeons. C. A. Reitman MD (✉), Department of Orthopaedics and PhysicalMedicine,Medical University of South Carolina, Charleston, SC, USA, Email: reitman@musc.edu