Surgeons failed to achieve their preoperative goal alignment of each sagittal parameter in approximately 25-30% of adult spinal deformity (ASD) patients and goal alignment for all three parameters was only achieved in 37.2% of patients. This is according to a recent study—the findings of which were published in the Global Spine Journal by Justin Smith (University of Virginia, Charlottesville, USA) et al—which also highlighted that those at greatest risk were patients with more severe deformity.
The data to come out of this prospective multicentre study through the International Spine Study Group shows that “advancements are needed to enable more consistent translation of preoperative alignment goals to the operating room” say the researchers.
Malalignment following ASD surgery can impact outcomes and increase mechanical complications. As such, Smith et al assessed whether preoperative goals for sagittal alignment following ASD surgery are achieved.
ASD patients were prospectively enrolled based on three criteria: deformity severity (PI-LL ≥25°, TPA ≥30°, sagittal vertical axis [SVA] ≥15 cm, TCobb≥70° or TLCobb≥50°), procedure complexity (≥12 levels fused, 3-CO or ACR) and/or age (>65 and ≥7 levels fused). The surgeon documented sagittal alignment goals prior to surgery and goals were compared with achieved alignment on first follow-up standing radiographs.
A total of 266 patients (68% women) with a mean age of 61 years (standard deviation [SD]= 14.6) were enrolled. Mean instrumented levels was 13.6 (SD= 3.8), and 23.2% had a 3-CO. Mean (SD) offsets (achieved-goal) were: SVA= −8.5mm (45.6mm), PI-LL= −4.6° (14.6°), thoracic kyphosis (TK)= 7.2° (14.7°), reflecting tendencies to undercorrect SVA and PI-LL and increase TK.
Goals were achieved for SVA, PI-LL, and TK in 74.4%, 71.4%, and 68.8% of patients, respectively, and was achieved for all three parameters in 37.2% of patients. Three factors were independently associated with achievement of all three alignment goals: use of picture archiving (PACs)/equivalent for surgical planning (p<0.001), lower baseline global coronal alignment (p=0.009), and surgery not including a 3-CO (p=0.037).
Speaking to Spinal News International, Smith said: “Despite increasing sophistication in our abilities to preoperatively plan spinal deformity corrections, there remain limitations in how these plans are effectively translated into the operating room. This study highlights the need for improved techniques and technologies to help bridge the gap between planning and operative execution.”