It is rare in orthopaedic surgery that we have the opportunity to look at the effects of our treatments over a substantial portion of our patients' lives. This paper studied two patient populations. The stated aim of the authors was "to evaluate whether spinal deformity or back pain in adolescence affects quality of life more in midterm to long-term follow-up." Their hypothesis was that the surgically-treated spondylolisthesis patients, because they require shorter fusions, would have better long-term health-related quality-of-life scores compared with patients with adolescent idiopathic scoliosis. Their method was a long-term look at surgical spine treatments with use of two accepted general and disease-specific outcomes tools. The authors had excellent retrieval (84%) at a mean follow-up time of fifteen-years (with the patients still only thirty years of age!).
This retrospective study has several limitations: They did not have benefit of controls—there were no patients who had been conservatively treated—and there were no preoperative evaluations of these patients with which to compare the postoperative outcomes. Data on the patients who had scoliosis were collected first, and data on the patients who had spondylolisthesis were collected several years later. Both populations have been reported on previously and separately1,2 from this same center. This report is a comparison of these two patient groups with a greater number of patients in each group.
The authors use these populations to attempt to answer a somewhat philosophical question about pain compared with deformity. However, scoliosis and spondylolisthesis involve elements of both pain and deformity. Scoliosis is a deformity that is associated with back pain in about one-third of adolescents. Spondylolisthesis is a deformity of segmental lumbosacral kyphosis and translation that initiates a compensatory lordosis. It also is associated with varying degrees of pain. Both patient populations had partial correction of the deformity; the residual scoliosis for a large portion of this population was previously reported to be >30°, and the residual spondylolisthesis was 41%.
The Scoliosis Research Society-24 (SRS-24) and SF-36 measures correlated well with each other for pain and several SF-36 subscores. However, there was no correlation between the magnitude of residual deformity (scoliosis or slip) and the SRS-24 or the SF-36 total or subscales. Perhaps if the residual deformities were more severe, a relationship would have been evident. The contemporary surgeon will wonder how current techniques would compare, as there would be a greater correction of deformity currently possible, but with different complications. By the time we can achieve comparable follow-up, treatment algorithms will have changed further still. Such is the challenge of evidence-based decision-making.
What can we learn from this retrospective study? Both patient populations seem to function well into young adulthood. A half-generation follow-up of more than 400 patients comprising 84% of the index population is good evidence of that. Only 6% to 8% of the patients had daily back pain often or at rest. Overall, the patients who had scoliosis scored more favorably than the patients with spondylolisthesis did. We do not know what the comparison will show in another forty years.
The finding that spondylolisthesis leads to lower general and disease-specific health outcomes, even after surgical treatment, is sensible. In apparent answer to the authors' hypothesis, even though the surgical fusion is more focal in patients with spondylolisthesis than in patients with scoliosis, the deformity and initial pain may be more challenging. Sagittal deformities tend to be more physically evident and functionally compromising than coronal deformities are. This study illustrates the difficulty and the work that remains to be done as health professionals begin to objectively compare different diseases and/or deformities and their treatment and translate them into meaningful terms.
*The author did not receive any outside funding or grants in support of his research for or preparation of this work. Neither he nor a member of his immediate family received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity. No commercial entity paid or directed, or agreed to pay or direct, any benefits to any research fund, foundation, division, center, clinical practice, or other charitable or nonprofit organization with which the author, or a member of his immediate family, is affiliated or associated.
1. Helenius I, Remes V, Yrjönen T, Ylikoski M, Schlenzka D, Helenius M, Poussa M.. Harrington and Cotrel-Dubousset instrumentation in adolescent idiopathic scoliosis. Long-term functional and radiographic outcomes. J Bone Joint Surg Am. 2003;85:2303-9.
2. Lamberg T, Remes V, Helenius I, Schlenzka D, Seitsalo S, Poussa M. Uninstrumented in-situ fusion for high-grade childhood and adolescent isthmic spondylolisthesis: long-term outcome. J Bone Joint Surg Am. 2007;89:512-8.