Paul Sponseller, president elect of the Scoliosis Research Society (SRS), talks to Spinal News International about the 26th International Meeting on Advanced Spine Techniques (IMAST 2019; 17–20 July, Amsterdam, The Netherlands). The mission of IMAST was to complement the Scoliosis Research Society Annual Meeting (SRS; 18–21 September, Montreal, Canada), focusing on more innovative techniques, which are in their earlier stages of development. Now in its 26th year, Sponseller believes the meeting “has an established place as one of the major meetings on the spine deformity calendar”.
Since the SRS is the premier society providing spinal deformity education, it is held inside the USA 40% of and outside of the USA 60% of the time. IMAST and the Annual Meeting complement each other in that way: when one is held in the USA, the other is held outside the USA. IMAST 2019 was held in Amsterdam for the first time this year, and over 725 attendees from five continents (a mixture of orthopaedic surgeons and neurosurgeons) enjoyed the conference, one of the highest numbers in recent years. The structure of the meeting was a blend of new peer-reviewed publications with didactic lectures. There were 75 peer-reviewed papers presented, mostly in parallel sessions, and audience voting determined the best papers.
Adult spine highlights
The Whitecloud Award-winning Best Clinical Paper was by Sravisht Iyer (Hospital for Special Surgery, New York, USA), a prospective randomised double-blind study showing that intravenous ketorolac reduces opioid consumption compared to intravenous acetaminophen or placebo after instrumented lumbar spine fusion while providing Improved pain control. The ketorolac group had nearly half the opioid use of the placebo group. There were no increased in-hospital complications and a trend toward decreased length of stay. “These findings are encouraging; longer term follow up will assess the impact of ketorolac on pseudarthrosis”, Iyer stated.
A long-term (10-year) prospective randomised investigational device exemption (IDE) trial of cervical disc arthroplasty (CDA) versus anterior cervical discectomy and fusion (ACDF) at two contiguous levels was summarised by Jeffrey McConnell (Leigh Valley Hospital, Allenstown, USA). Outcome measures included a composite overall success scale, and also a comparison of adverse events. With > 80% follow up in each group at 10 years, the overall success rate was 80% for CDA vs. 62% for the ADCF group. The authors conclude that “two-level CDA is a reliable, and perhaps better, alternative to fusion”. A subsequent symposium later in the meeting on ACDF versus CDA showed that equipoise remains among experts about whether one procedure is clearly better than the other.
A level one trial reported by Daniel Stein (Hospital for Special Surgery, New York, USA) and colleagues showed that topical steroid mixed in an absorbable gel matrix resulted in less dysphagia after multi-level ACDF surgery when compared to controls, and that the advantage remained up to one month of follow up.
On the cautionary side, Kevin Taliaferro (Henry Ford Hospital, Detroit, USA) presented a prospective randomised double blind study of patients undergoing posterolateral lumbar fusion showed that teriparatide provided no significant advantage in fusion rate compared to placebo when assessed by helical computed tomography (CT) at one year after surgery.
Pediatric spine highlights
The Basic Science award winner was a paper by Michelle C Welborn showing that collagen 10 biomarker (CXM, a breakdown product of collagen X from the growth plate which is broken down during endochondral ossification) is a real-time marker of growth velocity which compares favourably with more traditional radiographic markers. While not clinically available, “This test may guide decision-making in bracing and growth-friendly surgery”, Welborn stated.
Several papers discussed the results of anterior non-fusion scoliosis correction (ASC) or vertebral body tethering (VBT). Significant practice variation exists, but themes include delaying the procedure until at least Sanders 3 level maturity, and most papers reported reoperation rates slightly higher than those typically seen for posterior spinal fusion.
Several papers assessed the practical effect of advanced imaging technology (Navigation and robotics) in spinal surgery. A paper from Texas Scottish Rite Hospital (Dallas, USA) evaluated 1,667 spinal deformity operations by nine surgeons using fluoroscopically-guided or freehand technique. Of over 20,000 screws placed, the incidence of misplaced screws was only 0.14% for thoracic and 0.08% for lumbar screws. “These results call into question the need for expensive navigation technology”, stated presenting author Lori Karol. A related paper presented by Ivan Cheng (Stanford University Medical Center, Stanford, USA) used the MarketScan database to study the rates of neurological complications in 67,000 patients undergoing posterolateral lumbar fusions with or without navigation. Patients whose surgery employed navigation had a slightly higher rate of neurological injury (1.4 vs. 0.4%), which was statistically significant.
Next year’s IMAST will be moved to the spring on a permanent basis. Deformity specialists are encouraged to join the SRS in Athens, Greece, 1–4 April 2020.
Paul Sponseller is a professor of orthopaedic surgery at the Johns Hopkins School of Medicine (Baltimore, USA), and serves as the chief of the Division of Paediatric Orthopaedics at the Johns Hopkins Children’s Centre.