Multicenter, retrospective, institutional-review-board -approved study at 18 institutions in the United States with 24 treating investigators.
This study was designed to retrospectively assess the prevalence of spinopelvic malalignment in patients who underwent one- or two-level lumbar fusions for degenerative (nondeformity) indications and to assess the incidence of malalignment after fusion surgery as well as the rate of alignment preservation and/or correction in this population.
Spinopelvic malalignment after lumbar fusion has been associated with lower postoperative health-related quality of life and elevated risk of adjacent segment failure. The prevalence of spinopelvic malalignment in short-segment degenerative lumbar fusion procedures from a large sample of patients is heretofore unreported and may lead to an under-appreciation of these factors in surgical planning and ultimate preservation or correction of alignment.
Lateral preoperative and postoperative lumbar radiographs were retrospectively acquired from 578 one- or two-level lumbar fusion patients and newly measured for lumbar lordosis (LL), pelvic incidence (PI), and pelvic tilt. Patients were categorized at preop and postop time points as aligned if PI-LL < 10° or malaligned if PI-LL≥10°. Patients were grouped into categories based on their alignment progression from pre- to postoperative, with preserved (aligned to aligned), restored (malaligned to aligned), not corrected (malaligned to malaligned), and worsened (aligned to malaligned) designations.
Preoperatively, 173 (30%) patients exhibited malalignment. Postoperatively, 161 (28%) of patients were malaligned. Alignment was preserved in 63%, restored in 9%, not corrected in 21%, and worsened in 7% of patients.
This is the first multicenter study to evaluate the preoperative prevalence and postoperative incidence of spinopelvic malalignment in a large series of short-segment degenerative lumbar fusions, finding over 25% of patients out of alignment at both time points, suggesting that alignment preservation/restoration considerations should be incorporated into the decision-making of even degenerative lumbar spinal fusions.
Level of Evidence: 3
∗Neuroscience Institute, Virginia Mason Hospital and Medical Center, Seattle, WA
†OrthoCarolina, Charlotte, NC
‡Tabor Orthopedics, Memphis, TN
§Orthopaedic Specialists of Northwest Indiana, Munster, IN
¶University at Buffalo Neurosurgery, Buffalo, NY
||Spine Colorado, Durango, CO
∗∗Northwest Orthopaedic Specialists, Spokane, WA
††University of South Florida, Tampa, FL
‡‡Barrow Neurologic Institute, Phoenix, AZ.
Address correspondence and reprint requests to Jean-Christophe A. Leveque, MD, Neuroscience Institute, Virginia Mason Hospital and Medical Center, 1100 Ninth Avenue, Seattle, WA 98101; E-mail: email@example.com
Received 15 August, 2017
Revised 25 October, 2017
Accepted 3 November, 2017
The manuscript submitted does not contain information about medical device(s)/drug(s).
NuVasive, Inc. funds were received in support of this work.
Relevant financial activities outside the submitted work: board membership, consultancy, royalties, grants.