Table 1 Preoperative radiographic measurements across all patients with adult cervical deformity
Source: Passias PG, et al., “Evolution of Adult Cervical Deformity (ACD) Surgery Clinical and Radiographic Outcomes Based on a Multicenter Prospective Study: Are Behaviors and Outcomes Changing with Experience?”

AAOS Now

Published 3/25/2022
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Rebecca Araujo

Surgical Treatment for Adult Cervical Deformity: Changes in Approaches and Outcomes since 2013

In a study being presented during the AAOS 2022 Annual Meeting, Peter G. Passias, MD, FAAOS, and colleagues investigated how surgical treatment for adult cervical deformity (ACD) has changed over the past decade. Dr. Passias, who is a spine surgery specialist at the New York Spine Institute and a clinical associate professor of orthopaedic surgery at NYU Grossman School of Medicine, shared the findings.

According to the authors, the use of corrective surgery for cervical deformity has increased over time due to an aging population and advances in surgery and knowledge. “As the literature on ACD grows, it is important to investigate whether the improvement in understanding cervical deformity has translated into better surgical outcomes for patients,” wrote Dr. Passias and coauthors.

The investigators enrolled adult patients (aged ≥18 years) with ACD who had complete health-related quality-of-life (HRQL) and radiographic data preoperatively and at two years postoperatively. In total, 119 patients met inclusion criteria across multiple centers. Those patients were grouped according to the date of surgery. The “early” group included 72 patients who were treated between 2013 and 2014, and the “late” group included 47 patients treated between 2015 and 2017. Demographic, radiographic, and surgical data were compared across time periods. The researchers used multivariable regression analyses to evaluate differences in surgical, radiographic, and clinical outcomes between time periods.

The population was mostly female (67 percent), and mean age was 61.3 years. Average BMI was 29 kg/m2, and the average Charlson Comorbidity Index score was 0.96 ± 1.3. See Table 1 for baseline radiographic data.

Regarding surgical approach, 47.1 percent of cases were performed via a posterior approach, 18.5 percent via an anterior approach, and 34.5 percent via a combined approach. Fifty-one percent of patients also underwent spinal osteotomies. The average number of levels fused was 7.6 ± 3.8, and average estimated blood loss was 824 mL.

Between the early and late groups, there were no significant differences in age, frailty level, deformity, or cervical rigidity. The late group presented with higher Charlson Comorbidity Index scores (1.3 versus 0.72) and increased incidence of cerebrovascular disease (6 percent versus 0 percent) compared with the early group (both P <0.05). overall, there were no significant differences between groups in other variables, including number of levels fused, surgical approach, rates of reoperation, rates of distal junctional kyphosis, and hrqls scores (>P >0.05).

The authors noted a trend toward less invasive surgery over time. The late group had significantly lower levels of surgical invasiveness compared with the early group (P <0.05). when the researchers controlled for baseline deformity and age, there was also a reduction over time in the use of three-column osteotomies (tcos). the late group underwent significantly fewer tcos than the early group (odds ratio [or]="0.18,">P = 0.014).

“The TCO corrective technique balances an ability to restore a large degree of curvature to the spine with significantly increased risk of complications,” wrote Dr. Passias and colleagues. “From 2001 to 2011, utilization of TCOs in [spinal deformity] surgery rose to provide the necessary sagittal correction for increasingly complex and invasive surgeries. Since then, however, high complication risk coupled with novel age-adjusted alignment goals in [spinal deformity treatment] has shifted the philosophy toward less aggressive surgeries.”

TCO was most frequently performed in patients with deformity primarily in the cervical-thoracic region (48 percent), followed by the cervical region (23 percent) and thoracic region (19 percent). This distribution was similar between the early and late groups (P >0.05).

“The observed temporal decreases in TCOs and invasiveness of ACD procedures reflect consistency with the overall trend in [spinal deformity treatment],” the authors commented.
“Surgeons are opting for more physiologically shaped reconstructions, reserving aggressive pedicle subtraction osteotomies and vertebral column resections for cases of rigid kyphotic cervical deformity with an apex of deformity in a hyperkyphotic upper thoracic spine, or more commonly at the cervicothoracic junction.”

The researchers added that, in the late group, “Postoperative deformity occurred less often when classifying by either SRS-Schwab or Ames Modified Criteria.” At two-year follow up, the late group had fewer patients with a moderate/high Ames horizontal modifier (71.7 percent versus 88.2 percent) or with +/++ SRS Schwab ratings for pelvic tilt (9.1 percent versus 39.5 percent) compared with the early group.

After controlling for baseline deformity, age, number of levels fused, and use of TCOs, patients treated between 2015 and 2017 had significantly lower odds of adverse events (OR = 0.15, P = 0.03) and neurological complications (OR = 0.1, P = 0.03) than patients treated between 2013 and 2014.

In summary, Dr. Passias and colleagues wrote, “Despite a population with greater comorbidity and associated risk, outcomes remained consistent between the early and later time periods, indicating general improvements in care. The later cohort demonstrated fewer TCOs, less suboptimal realignments, and concomitant reductions in adverse events and neurologic complications. This may suggest greater facility with less invasive techniques.”

The study will be on display as Poster P0836 on Friday in Academy Hall, from 7 a.m. to 5 p.m.

Dr. Passias’ coauthors of “Evolution of Adult Cervical Deformity (ACD) Surgery Clinical and Radiographic Outcomes Based on a Multicenter Prospective Study: Are Behaviors and Outcomes Changing with Experience?” are Oscar Krol, BA; Kevin Ali Moattari, BS; Virginie Lafage, PhD; Renaud Lafage, MS; Han Jo Kim, MD, FAAOS; Alan H. Daniels, MD, FAAOS; Bassel Diebo, MD; Themistocles Stavros Protopsaltis, MD; Gregory Michael Mundis Jr, MD; Khaled M. Kebaish, MD, FAAOS; Maria Alexandra Soroceanu, MD; Justin K. Scheer, MD; D. Kojo Hamilton, MD; Eric O. Klineberg, MD, FAAOS; Andrew J. Schoenfeld, MD, FAAOS; Shaleen Vira, MD; Breton G. Line, BS; Robert A. Hart, MD, FAAOS; Douglas C. Burton, MD, FAAOS; Frank J. Schwab, MD; Christopher I. Shaffrey, MD, FAAOS; Robert Shay Bess, MD, FAAOS; Justin S. Smith, MD; and Christopher Ames, MD.

Rebecca Araujo is the associate editor of AAOS Now. She can be reached at raraujo@aaos.org.