AAOS Now

Published 2/1/2015
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Mary Ann Porucznik

Studies Examine Impact of Treatment for Adult Spinal Deformity

Surgical treatment found more effective at 2-year follow-up

Two prospective, multicenter studies by the International Spine Study Group comparing surgical and nonsurgical treatment of adult spinal deformity were recognized as “Best Papers” during the 2014 annual meeting of the North American Spine Society (NASS). Both papers found that surgical treatment for symptomatic adult spinal deformities, such as scoliosis and kyphosis, can provide significantly more improvement in health-related quality of life, compared to nonsurgical treatments.

Measuring outcomes
The first paper, “Outcomes of Operative and Nonoperative Treatment for Adult Spinal Deformity (ASD): A Prospective, Multicenter Matched and Unmatched Cohort Assessment with Minimum 2-Year Follow-Up,” involved 689 patients with ASD. Outcomes were assessed using baseline and minimum 2-year health-related quality of life measures (general health, pain, and disability), including the Scoliosis Research Society Questionnaire 22r (SRS-22r), Oswestry Disability Index (ODI), physical and mental components of the Short-Form 36 Health Questionnaire (SF-36), and back and leg pain numeric rating scale scores.

All patients were older than age 18 and researchers used propensity scores to match those treated surgically and those treated nonsurgically based on the following parameters (all baseline measures):

  • ODI, SRS-22r, and leg pain scores
  • maximum thoracolumbar/lumbar Cobb angle
  • pelvic incidence to lumbar lordosis mismatch (PI-LL)

Of the 689 patients who met the inclusion criteria, 286 were treated surgically and 403 were treated nonsurgically. Mean age in both groups was similar (surgical group, 53 years; nonsurgical group, 55 years). However, the surgical group had a higher 2-year follow-up rate (86 percent) than the nonsurgical group (55 percent).

At baseline, surgical patients had significantly worse health-related quality of life as well as worse deformity than nonsurgical patients. Before reaching the minimum 2-year follow-up, 38 patients in the nonsurgical treatment group opted for surgical treatment and their results were included in that analysis. Overall minor and major complication rates for surgically treated patients were 53 percent and 40 percent, respectively.

At the minimum 2-year follow-up, patients treated surgically showed significant improvement (P = 0.001) in all health-related quality of life measures. Among the 97 matched pairs identified based on propensity scores, surgically treated patients showed significant improvement in all health-related quality of life measures (except for the mental component of the SF-36), while patients treated nonsurgically did not show significant improvement in any of the measures. “At best,” wrote the authors, “nonsurgical treatment appears to maintain presenting levels of pain and disability.”

Assessing function
Similarly, a second study (Operative Treatment of Adult Spinal Deformity [ASD] Improves Disease State and Physical Function Regardless of Age and Deformity Type, while Nonoperative Treatment Has No Impact: A 2-Year Prospective Analysis) by the same group found that nonsurgical treatment had no impact on disease state and physical function at 2-year follow-up, regardless of age and deformity type. ASD can be a debilitating disease that affects physical function to a similar degree as diabetes and heart disease, and patients with severe sagittal malalignment may have disabilities similar to those of poorly functioning amputee patients.

The 302 patients in the study had no prior spine surgery and were 18 years or older; all patients had a minimum 2-year follow-up. ASD was evaluated based on the type of scoliosis (thoracic, lumbar, combined, or none) and the severity of sagittal malalignment, measured by the sagittal vertical axis (SVA). Patients were divided into two groups based on treatment (surgical or nonsurgical) and baseline and 2-year follow-up SF-36 physical and mental component scores were calculated for each group and compared to U.S. normative and disease-specific values.

SF-36 scores were reported as norm-based values (NBS) and a minimum of 3 NBS points was defined as the minimal clinically important difference. Initially, the surgical group had lower SF-36 physical scores than the nonsurgical group (34.5 vs 44.6). At 2-year follow-up, however, SF-36 physical score values were similar for patients in both groups (43.4 surgical group vs 43.8 nonsurgical group).

Researchers also noted that at 2-year follow-up, the corresponding disease states improved in patients treated surgically, but not for patients treated nonsurgically, regardless of deformity type.

“ASD patients demonstrate severe disability compared to U.S. norms,” they noted. “Surgical treatment provides improvement for all deformity types whereas nonsurgical treatment does not improve disease state regardless of deformity type.” Nonetheless, physical component values remained below population norms at minimum 2-year follow-up.

“These are timely and useful studies because our aging population will be facing more symptomatic spinal degeneration and deformity than ever before,” said Charles A. Reitman, MD, professor and vice chair of orthopedic surgery at Baylor College of Medicine and program chair for the meeting. “As technology and surgical expertise continue to grow, additional research is critical to ensure that patients and physicians understand the appropriate indications for surgery. This will enable us to optimize outcomes for patients.”

Coauthors for the outcomes study include the International Spine Study Group; Justin S. Smith, MD, PhD; Virginie Lafage, PhD; Christopher I. Shaffrey, MD; Frank J. Schwab, MD; Richard A. Hostin, MD; Oheneba Boachie-Adjei, MD; Behrooz A. Akbarnia, MD; Eric O. Klineberg, MD; Munish C. Gupta, MD; Themistocles S. Protopsaltis, MD; Justin K. Scheer, BS; Kai-Ming G. Fu, MD, PhD; Gregory M. Mundis Jr, MD; Khaled M. Kebaish, MD; Breton Line; Han Jo Kim, MD; Vedat Deviren, MD; Robert A. Hart, MD; Douglas C. Burton, MD; R. Shay Bess, MD; Christopher P. Ames, MD. Additional coauthors for the function study include Thomas J. Errico, MD, and Michael F. O’Brien, MD. One or more of the authors reported potential conflicts of interest; visit www.aaos.org/disclosure for more information.

Mary Ann Porucznik is managing editor, AAOS Now; she can be reached at porucznik@aaos.org

Bottom Line

  • Two award-winning studies presented at the NASS annual meeting compared outcomes and function of patients with adult spinal deformity who were treated surgically or nonsurgically.
  • In the outcomes study, patients treated surgically started with lower baseline parameters than those treated nonsurgically, but showed significant improvement in all health-related quality of life measures at 2 years; patients treated nonsurgically showed no improvement.
  • In the function study, patients treated surgically had improved function at 2 years, but “nonsurgical treatment did not improve disease state regardless of deformity type.”
  • Additional research is required to ensure that patients and physicians understand the appropriate indications for surgery.