Less invasive spinal deformity surgery: the impact of the learning curve at tertiary spine care centers

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>The past decade has seen major advances in techniques for treating more complex spinal disorders using minimally invasive surgery (MIS). While appealing from the standpoint of patient perioperative outcomes, a major impediment to adoption has been the significant learning curve in utilizing MIS techniques.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>Data were retrospectively analyzed from a multicenter series of adult spinal deformity surgeries treated at eight tertiary spine care centers in the period from 2008 to 2015. All patients had undergone a less invasive or hybrid approach for a deformity correction satisfying the following inclusion criteria at baseline: coronal Cobb angle ≥ 20°, sagittal vertical axis (SVA) &gt; 5 cm, or pelvic tilt &gt; 20°. Analyzed data included baseline demographic details, severity of deformity, surgical metrics, clinical outcomes (numeric rating scale [NRS] score and Oswestry Disability Index [ODI]), radiographic outcomes, and complications. A minimum follow-up of 2 years was required for study inclusion.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>Across the 8-year study period, among 222 patients, there was a trend toward treating increasingly morbid patients, with the mean age increasing from 50.7 to 62.4 years (p = 0.013) and the BMI increasing from 25.5 to 31.4 kg/m<jats:sup>2</jats:sup> (p = 0.12). There was no statistical difference in the severity of coronal and sagittal deformity treated over the study period. With regard to radiographic changes following surgery, there was an increasing emphasis on sagittal correction and, conversely, less coronal correction. There was no statistically significant difference in clinical outcomes over the 8-year period, and meaningful improvements were seen in all years (ODI range of improvement: 15.0–26.9). Neither were there statistically significant differences in major complications; however, minor complications were seen less often as the surgeons gained experience (p = 0.064). Operative time was decreased on average by 47% over the 8-year period.</jats:p><jats:p>Trends in surgical practice were seen as well. Total fusion construct length was unchanged until the last year when there was a marked decrease in conjunction with a decrease in interbody levels treated (p = 0.004) while obtaining a higher degree of sagittal correction, suggesting more selective but powerful interbody reduction methods as reflected by an increase in the lateral and anterior column resection techniques being utilized.</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>The use of minimally invasive methods for adult spinal deformity surgery has evolved over the past decade. Experienced surgeons are treating older and more morbid patients with similar outcomes. A reliance on selective, more powerful interbody approaches is increasing as well.</jats:p></jats:sec>

Scoliosis surgery in adulthood: what challenges for what outcome?

“…Minimal invasive techniques usually combine posterior percutaneous instrumentation and anterior retroperitoneal approaches using interbody fusion cages. This combined MIS approach has the advantage of sparing paravertebral muscle dissection, minimal blood Experienced surgeons are treating older and more morbid patients with similar outcomes in mild and moderate spinal deformities (14). Sagittal deformity correction mainly relies on powerful interbody reduction methods that imply a resection of the degenerated intervertebral disc and anterior longitudinal ligament.…”

“…It has been demonstrated that low back pain and leg pain improve and that the segmental lumbar deformity can be efficiently corrected with MIS techniques. (14,18). This strategy seems appropriate in mild and moderate ASD which present degenerative changes of the lumbar spine and a remaining curve flexibility (19).…”

Utilization of anterior lumbar interbody fusion for severe kyphotic deformity secondary to Pott’s disease: illustrative case

“… 19 In addition, a longitudinal multicenter analysis of minimally invasive surgery identified a shift toward ALIF surgery and away from three-column osteotomies with the advent of hyperlordotic cages; however, centers continue to differ in their use of lateral ACR and posterior osteotomy techniques. 20 It is evident that there is no singular approach to planning spinal deformity surgery, and various factors related to the patient’s medical stability and surgeon’s technical abilities must be considered.…”

Big Data in the Clinical Neurosciences

“…Although the ASR will become the largest spine registry, there are other highly productive databases that further highlight the importance of this growing area of data science. For example, the International Spine Study Group (ISSG) has published primarily on treatment of adult spinal deformity (ASD) over the past decade and have recently begun to examine long-term outcomes in minimally invasive ASD surgery [14]. Surgical innovation and new technology may drive these evolutions in practice initially, but ultimately favorable long-term outcomes lead to broad acceptance within the field, which now is often augmented by analysis of large surgical databases.…”