Kristina Bianco, Robert Norton, Frank Schwab, Justin S. Smith, Eric Klineberg, Ibrahim Obeid, Gregory Mundis Jr., Christopher I. Shaffrey, Khaled Kebaish, Richard Hostin, Robert Hart, Munish C. Gupta, Douglas Burton, Christopher Ames, Oheneba Boachie-Adjei, Themistocles S. Protopsaltis and Virginie Lafage
Three-column resection osteotomies (3COs) are commonly performed for sagittal deformity but have high rates of reported complications. Authors of this study aimed to examine the incidence of and intercenter variability in major intraoperative complications (IOCs), major postoperative complications (POCs) up to 6 weeks postsurgery, and overall complications (that is, both IOCs and POCs). They also aimed to investigate the incidence of and intercenter variability in blood loss during 3CO procedures.
The incidence of IOCs, POCs, and overall complications associated with 3COs were retrospectively determined for the study population and for each of 8 participating surgical centers. The incidence of major blood loss (MBL) over 4 L and the percentage of total blood volume lost were also determined for the study population and each surgical center. Complication rates and blood loss were compared between patients with one and those with two osteotomies, as well as between patients with one thoracic osteotomy (ThO) and those with one lumbar or sacral osteotomy (LSO). Risk factors for developing complications were determined.
Retrospective review of prospectively acquired data for 423 consecutive patients who had undergone 3CO at 8 surgical centers was performed. The incidence of major IOCs, POCs, and overall complications was 7%, 39%, and 42%, respectively, for the study population overall. The most common IOC was spinal cord deficit (2.6%) and the most common POC was unplanned return to the operating room (19.4%). Patients with two osteotomies had more POCs (56% vs 38%, p = 0.04) than the patients with one osteotomy. Those with ThO had more IOCs (16% vs 6%, p = 0.03), POCs (58% vs 34%, p < 0.01), and overall complications (67% vs 37%, p < 0.01) than the patients with LSO. There was significant variation in the incidence of IOCs, POCs, and overall complications among the 8 sites (p < 0.01). The incidence of MBL was 24% for the study population, which varied significantly between sites (p < 0.01). Patients with MBL had a higher risk of IOCs, POCs, and overall complications (OR 2.15, 1.76, and 2.01, respectively). The average percentage of total blood volume lost was 55% for the study population, which also varied among sites (p < 0.01).
Given the complexity of 3COs for spinal deformity, it is important for spine surgeons to understand the risk factors and complication rates associated with these procedures. In this study, the overall incidence of major complications following 3CO procedures was 42%. Risks for developing complications included an older age (> 60 years), two osteotomies, ThO, and MBL.
Abstracts of the 2013 Annual Meeting of the AANS/CNS Section on Disorders of the Spine and Peripheral Nerves
Phoenix, Arizona • March 6–9, 2013
Virginie Lafage, Neil J. Bharucha, Frank Schwab, Robert A. Hart, Douglas Burton, Oheneba Boachie-Adjei, Justin S. Smith, Richard Hostin, Christopher Shaffrey, Munish Gupta, Behrooz A. Akbarnia and Shay Bess
Sagittal spinopelvic imbalance is a major contributor to pain and disability for patients with adult spinal deformity (ASD). Preoperative planning is essential for pedicle subtraction osteotomy (PSO) candidates; however, current methods are often inaccurate because no formula to date predicts both postoperative sagittal balance and pelvic alignment. The authors of this study aimed to evaluate the accuracy of 2 novel formulas in predicting postoperative spinopelvic alignment after PSO.
This study is a multicenter retrospective consecutive PSO case series. Adults with spinal deformity (> 21 years old) who were treated with a single-level lumbar PSO for sagittal imbalance were evaluated. All patients underwent preoperative and a minimum of 6-month postoperative radiography. Two novel formulas were used to predict the postoperative spinopelvic alignment. The results predicted by the formulas were then compared with the actual postoperative radiographic values, and the formulas' ability to identify successful (sagittal vertical axis [SVA] ≤ 50 mm and pelvic tilt [PT] ≤ 25°) and unsuccessful (SVA > 50 mm or PT > 25°) outcomes was evaluated.
Ninety-nine patients met inclusion criteria. The median absolute error between the predicted and actual PT was 4.1° (interquartile range 2.0°–6.4°). The median absolute error between the predicted and actual SVA was 27 mm (interquartile range 11–47 mm). Forty-one of 54 patients with a formula that predicted a successful outcome had a successful outcome as shown by radiography (positive predictive value = 0.76). Forty-four of 45 patients with a formula that predicted an unsuccessful outcome had an unsuccessful outcome as shown by radiography (negative predictive value = 0.98).
The spinopelvic alignment formulas were accurate when predicting unsuccessful outcomes but less reliable when predicting successful outcomes. The preoperative surgical plan should be altered if an unsuccessful result is predicted. However, even after obtaining a predicted successful outcome, surgeons should ensure that the predicted values are not too close to unsuccessful values and should identify other variables that may affect alignment. In the near future, it is anticipated that the use of these formulas will lead to better surgical planning and improved outcomes for patients with complex ASD.
Virginie Lafage, Frank Schwab, Shaleen Vira, Robert Hart, Douglas Burton, Justin S. Smith, Oheneba Boachie-Adjei, Alexis Shelokov, Richard Hostin, Christopher I. Shaffrey, Munish Gupta, Behrooz A. Akbarnia, Shay Bess and Jean-Pierre Farcy
Pedicle subtraction osteotomy (PSO) is a spinal realignment technique that may be used to correct sagittal spinal imbalance. Theoretically, the level and degree of resection via a PSO should impact the degree of sagittal plane correction in the setting of deformity. However, the quantitative effect of PSO level and focal angular change on postoperative spinopelvic parameters has not been well described. The purpose of this study is to analyze the relationship between the level/degree of PSO and changes in global sagittal balance and spinopelvic parameters.
In this multicenter retrospective study, 70 patients (54 women and 16 men) underwent lumbar PSO surgery for spinal imbalance. Preoperative and postoperative free-standing sagittal radiographs were obtained and analyzed by regional curves (lumbar, thoracic, and thoracolumbar), pelvic parameters (pelvic incidence and pelvic tilt [PT]) and global balance (sagittal vertical axis [SVA] and T-1 spinopelvic inclination). Correlations between PSO parameters (level and degree of change in angle between the 2 adjacent vertebrae) and spinopelvic measurements were analyzed.
Pedicle subtraction osteotomy distribution by level and degree of correction was as follows: L-1 (6 patients, 24°), L-2 (15 patients, 24°), L-3 (29 patients, 25°), and L-4 (20 patients, 22°). There was no significant difference in the focal correction achieved by PSO by level. All patients demonstrated changes in preoperative to postoperative parameters including increased lumbar lordosis (from 20° to 49°, p < 0.001), increased thoracic kyphosis (from 30° to 38°, p < 0.001), decreased SVA and T-1 spinopelvic inclination (from 122 to 34 mm, p < 0.001 and from +3° to −4°, p < 0.001, respectively), and decreased PT (from 31° to 23°, p < 0.001). More caudal PSO was correlated with greater PT reduction (r = −0.410, p < 0.05). No correlation was found between SVA correction and PSO location. The PSO degree was correlated with change in thoracic kyphosis (r = −0.474, p < 0.001), lumbar lordosis (r = 0.667, p < 0.001), sacral slope (r = 0.426, p < 0.001), and PT (r = −0.358, p < 0.005).
The degree of PSO resection correlates more with spinopelvic parameters (lumbar lordosis, thoracic kyphosis, PT, and sacral slope) than PSO level. More importantly, PSO level impacts postoperative PT correction but not SVA.