Taemin Oh, Justin K. Scheer, Robert Eastlack, Justin S. Smith, Virginie Lafage, Themistocles S. Protopsaltis, Eric Klineberg, Peter G. Passias, Vedat Deviren, Richard Hostin, Munish Gupta, Shay Bess, Frank Schwab, Christopher I. Shaffrey and Christopher P. Ames
Alignment changes in the cervical spine that occur following surgical correction for thoracic deformity remain poorly understood. The purpose of this study was to evaluate such changes in a cohort of adults with thoracic deformity treated surgically.
The authors conducted a multicenter retrospective analysis of consecutive patients with thoracic deformity. Inclusion criteria for this study were as follows: corrective osteotomy for thoracic deformity, upper-most instrumented vertebra (UIV) between T-1 and T-4, lower-most instrumented vertebra (LIV) at or above L-5 (LIV ≥ L-5) or at the ilium (LIV-ilium), and a minimum radiographic follow-up of 2 years. Sagittal radiographic parameters were assessed preoperatively as well as at 3 months and 2 years postoperatively, including the C-7 sagittal vertical axis (SVA), C2–7 cervical lordosis (CL), C2–7 SVA, T-1 slope (T1S), T1S minus CL (T1S-CL), T2–12 thoracic kyphosis (TK), apical TK, lumbar lordosis (LL), pelvic incidence (PI), PI-LL, pelvic tilt (PT), and sacral slope (SS).
Fifty-seven patients with a mean age of 49.1 ± 14.6 years met the study inclusion criteria. The preoperative prevalence of increased CL (CL > 15°) was 48.9%. Both 3-month and 2-year apical TK improved from baseline (p < 0.05, statistically significant). At the 2-year follow-up, only the C2–7 SVA increased significantly from baseline (p = 0.01), whereas LL decreased from baseline (p < 0.01). The prevalence of increased CL was 35.3% at 3 months and 47.8% at 2 years, which did not represent a significant change. Postoperative cervical alignment changes were not significantly different from preoperative values regardless of the LIV (LIV ≥ L-5 or LIV-ilium, p > 0.05 for both). In a subset of patients with a maximum TK ≥ 60° (35 patients) and 3-column osteotomy (38 patients), no significant postoperative cervical changes were seen.
Increased CL is common in adult spinal deformity patients with thoracic deformities and, unlike after lumbar corrective surgery, does not appear to normalize after thoracic corrective surgery. Cervical sagittal malalignment (C2–7 SVA) also increases postoperatively. Surgeons should be aware that spontaneous cervical alignment normalization might not occur following thoracic deformity correction.
Justin S. Smith, Ellen Shaffrey, Eric Klineberg, Christopher I. Shaffrey, Virginie Lafage, Frank J. Schwab, Themistocles Protopsaltis, Justin K. Scheer, Gregory M. Mundis Jr., Kai-Ming G. Fu, Munish C. Gupta, Richard Hostin, Vedat Deviren, Khaled Kebaish, Robert Hart, Douglas C. Burton, Breton Line, Shay Bess, Christopher P. Ames and The International Spine Study Group
Improved understanding of rod fracture (RF) following adult spinal deformity (ASD) surgery could prove valuable for surgical planning, patient counseling, and implant design. The objective of this study was to prospectively assess the rates of and risk factors for RF following surgery for ASD.
This was a prospective, multicenter, consecutive series. Inclusion criteria were ASD, age > 18 years, ≥5 levels posterior instrumented fusion, baseline full-length standing spine radiographs, and either development of RF or full-length standing spine radiographs obtained at least 1 year after surgery that demonstrated lack of RF. ASD was defined as presence of at least one of the following: coronal Cobb angle ≥20°, sagittal vertical axis (SVA) ≥5 cm, pelvic tilt (PT) ≥25°, and thoracic kyphosis ≥60°.
Of 287 patients who otherwise met inclusion criteria, 200 (70%) either demonstrated RF or had radiographic imaging obtained at a minimum of 1 year after surgery showing lack of RF. The patients' mean age was 54.8 ± 15.8 years; 81% were women; 10% were smokers; the mean body mass index (BMI) was 27.1 ± 6.5; the mean number of levels fused was 12.0 ± 3.8; and 50 patients (25%) had a pedicle subtraction osteotomy (PSO). The rod material was cobalt chromium (CC) in 53%, stainless steel (SS), in 26%, or titanium alloy (TA) in 21% of cases; the rod diameters were 5.5 mm (in 68% of cases), 6.0 mm (in 13%), or 6.35 mm (in 19%). RF occurred in 18 cases (9.0%) at a mean of 14.7 months (range 3–27 months); patients without RF had a mean follow-up of 19 months (range 12–24 months). Patients with RF were older (62.3 vs 54.1 years, p = 0.036), had greater BMI (30.6 vs 26.7, p = 0.019), had greater baseline sagittal malalignment (SVA 11.8 vs 5.0 cm, p = 0.001; PT 29.1° vs 21.9°, p = 0.016; and pelvic incidence [PI]–lumbar lordosis [LL] mismatch 29.6° vs 12.0°, p = 0.002), and had greater sagittal alignment correction following surgery (SVA reduction by 9.6 vs 2.8 cm, p < 0.001; and PI-LL mismatch reduction by 26.3° vs 10.9°, p = 0.003). RF occurred in 22.0% of patients with PSO (10 of the 11 fractures occurred adjacent to the PSO level), with rates ranging from 10.0% to 31.6% across centers. CC rods were used in 68% of PSO cases, including all with RF. Smoking, levels fused, and rod diameter did not differ significantly between patients with and without RF (p > 0.05). In cases including a PSO, the rate of RF was significantly higher with CC rods than with TA or SS rods (33% vs 0%, p = 0.010). On multivariate analysis, only PSO was associated with RF (p = 0.001, OR 5.76, 95% CI 2.01–15.8).
Rod fracture occurred in 9.0% of ASD patients and in 22.0% of PSO patients with a minimum of 1-year follow-up. With further follow-up these rates would likely be even higher. There was a substantial range in the rate of RF with PSO across centers, suggesting potential variations in technique that warrant future investigation. Due to higher rates of RF with PSO, alternative instrumentation strategies should be considered for these cases.
Justin S. Smith, Manish Singh, Eric Klineberg, Christopher I. Shaffrey, Virginie Lafage, Frank J. Schwab, Themistocles Protopsaltis, David Ibrahimi, Justin K. Scheer, Gregory Mundis Jr., Munish C. Gupta, Richard Hostin, Vedat Deviren, Khaled Kebaish, Robert Hart, Douglas C. Burton, Shay Bess and Christopher P. Ames
Increased sagittal vertical axis (SVA) correlates strongly with pain and disability for adults with spinal deformity. A subset of patients with sagittal spinopelvic malalignment (SSM) have flatback deformity (pelvic incidence–lumbar lordosis [PI-LL] mismatch > 10°) but remain sagittally compensated with normal SVA. Few data exist for SSM patients with flatback deformity and normal SVA. The authors' objective was to compare baseline disability and treatment outcomes for patients with compensated (SVA < 5 cm and PI-LL mismatch > 10°) and decompensated (SVA > 5 cm) SSM.
The study was a multicenter, prospective analysis of adults with spinal deformity who consecutively underwent surgical treatment for SSM. Inclusion criteria included age older than 18 years, presence of adult spinal deformity with SSM, plan for surgical treatment, and minimum 1-year follow-up data. Patients with SSM were divided into 2 groups: those with compensated SSM (SVA < 5 cm and PI-LL mismatch > 10°) and those with decompensated SSM (SVA ≥ 5 cm). Baseline and 1-year follow-up radiographic and health-related quality of life (HRQOL) outcomes included Oswestry Disability Index, Short Form–36 scores, and Scoliosis Research Society–22 scores. Percentages of patients achieving minimal clinically important difference (MCID) were also assessed.
A total of 125 patients (27 compensated and 98 decompensated) met inclusion criteria. Compared with patients in the compensated group, patients in the decompensated group were older (62.9 vs 55.1 years; p = 0.004) and had less scoliosis (43° vs 54°; p = 0.002), greater SVA (12.0 cm vs 1.7 cm; p < 0.001), greater PI-LL mismatch (26° vs 20°; p = 0.013), and poorer HRQOL scores (Oswestry Disability Index, Short Form-36 physical component score, Scoliosis Research Society-22 total; p ≤ 0.016). Although these baseline HRQOL differences between the groups reached statistical significance, only the mean difference in Short Form–36 physical component score reached threshold for MCID. Compared with baseline assessment, at 1 year after surgery improvement was noted for patients in both groups for mean SVA (compensated –1.1 cm, decompensated +4.8 cm; p ≤ 0.009), mean PI-LL mismatch (compensated 6°, decompensated 5°; p < 0.001), and all HRQOL measures assessed (p ≤ 0.005). No significant differences were found between the compensated and decompensated groups in the magnitude of HRQOL score improvement or in the percentages of patients achieving MCID for each of the outcome measures assessed.
Decompensated SSM patients with elevated SVA experience significant disability; however, the amount of disability in compensated SSM patients with flatback deformity caused by PI-LL mismatch but normal SVA is underappreciated. Surgical correction of SSM demonstrated similar radiographic and HRQOL score improvements for patients in both groups. Evaluation of SSM should extend beyond measuring SVA. Among patients with concordant pain and disability, PI-LL mismatch must be evaluated for SSM patients and can be considered a primary indication for surgery.
Kseniya Slobodyanyuk, Caroline E. Poorman, Justin S. Smith, Themistocles S. Protopsaltis, Richard Hostin, Shay Bess, Gregory M. Mundis Jr., Frank J. Schwab and Virginie Lafage
The goal of this study was to determine the outcome and risk factors in patients with adult spinal deformity (ASD) who elected to receive nonoperative care.
In this retrospective study the authors reviewed a nonoperative branch of the International Spine Study Group database, derived from 10 sites across the US. Specific inclusion criteria included nonoperative treatment for ASD and the availability of Scoliosis Research Society (SRS)-22 scores and radiographic data at baseline (BL) and at 1-year (1Y) follow-up. Health-related quality of life measures were assessed using the SRS-22 and radiographic data. Changes in SRS-22 scores were evaluated by domain and expressed in number of minimum clinically important differences (MCIDs) gained or lost; BL and 1Y scores were also compared with age- and sex-matched normative references.
One hundred eighty-nine patients (mean age 53 years, 86% female) met inclusion criteria. Pain was the domain with the largest offset for 43% of patients, followed by the Appearance (23%), Activity (18%), and Mental (15%) domains. On average, patients improved 0.3 MCID in Pain over 1Y, without changes in Activity or Appearance. Baseline scores significantly impacted 1Y outcomes, with up to 85% of patients in the mildest category of deformity being classified as < 1 MCID of normative reference at 1Y, versus 0% of patients with the most severe initial deformity. Baseline radiographic parameters did not correlate with outcome.
Patients who received nonoperative care are significantly more disabled than age- and sex-matched normative references. The likelihood for a patient to reach SRS scores similar to the normative reference at 1Y decreases with increased BL disability. Nonoperative treatment is a viable option for certain patients with ASD, and up to 24% of patients demonstrated significant improvement over 1Y with nonoperative care.
Juan S. Uribe, Armen R. Deukmedjian, Praveen V. Mummaneni, Kai-Ming G. Fu, Gregory M. Mundis Jr., David O. Okonkwo, Adam S. Kanter, Robert Eastlack, Michael Y. Wang, Neel Anand, Richard G. Fessler, Frank La Marca, Paul Park, Virginie Lafage, Vedat Deviren, Shay Bess and Christopher I. Shaffrey
It is hypothesized that minimally invasive surgical techniques lead to fewer complications than open surgery for adult spinal deformity (ASD). The goal of this study was to analyze matched patient cohorts in an attempt to isolate the impact of approach on adverse events.
Two multicenter databases queried for patients with ASD treated via surgery and at least 1 year of follow-up revealed 280 patients who had undergone minimally invasive surgery (MIS) or a hybrid procedure (HYB; n = 85) or open surgery (OPEN; n = 195). These patients were divided into 3 separate groups based on the approach performed and were propensity matched for age, preoperative sagittal vertebral axis (SVA), number of levels fused posteriorly, and lumbar coronal Cobb angle (CCA) in an attempt to neutralize these patient variables and to make conclusions based on approach only. Inclusion criteria for both databases were similar, and inclusion criteria specific to this study consisted of an age > 45 years, CCA > 20°, 3 or more levels of fusion, and minimum of 1 year of follow-up. Patients in the OPEN group with a thoracic CCA > 75° were excluded to further ensure a more homogeneous patient population.
In all, 60 matched patients were available for analysis (MIS = 20, HYB = 20, OPEN = 20). Blood loss was less in the MIS group than in the HYB and OPEN groups, but a significant difference was only found between the MIS and the OPEN group (669 vs 2322 ml, p = 0.001). The MIS and HYB groups had more fused interbody levels (4.5 and 4.1, respectively) than the OPEN group (1.6, p < 0.001). The OPEN group had less operative time than either the MIS or HYB group, but it was only statistically different from the HYB group (367 vs 665 minutes, p < 0.001). There was no significant difference in the duration of hospital stay among the groups. In patients with complete data, the overall complication rate was 45.5% (25 of 55). There was no significant difference in the total complication rate among the MIS, HYB, and OPEN groups (30%, 47%, and 63%, respectively; p = 0.147). No intraoperative complications were reported for the MIS group, 5.3% for the HYB group, and 25% for the OPEN group (p < 0.03). At least one postoperative complication occurred in 30%, 47%, and 50% (p = 0.40) of the MIS, HYB, and OPEN groups, respectively. One major complication occurred in 30%, 47%, and 63% (p = 0.147) of the MIS, HYB, and OPEN groups, respectively. All patients had significant improvement in both the Oswestry Disability Index (ODI) and visual analog scale scores after surgery (p < 0.001), although the MIS group did not have significant improvement in leg pain. The occurrence of complications had no impact on the ODI.
Results in this study suggest that the surgical approach may impact complications. The MIS group had significantly fewer intraoperative complications than did either the HYB or OPEN groups. If the goals of ASD surgery can be achieved, consideration should be given to less invasive techniques.
Justin K. Scheer, Virginie Lafage, Justin S. Smith, Vedat Deviren, Richard Hostin, Ian M. McCarthy, Gregory M. Mundis, Douglas C. Burton, Eric Klineberg, Munish C. Gupta, Khaled M. Kebaish, Christopher I. Shaffrey, Shay Bess, Frank Schwab, Christopher P. Ames and the International Spine Study Group (ISSG)
Spinal osteotomies for adult spinal deformity correction may include resection of all 3 spinal columns (pedicle subtraction osteotomy [PSO] and vertebral column resection [VCR]). The relationship between patient age and health-related quality of life (HRQOL) outcomes for patients undergoing major spinal deformity correction via PSO or VCR has not been well characterized. The goal of this study was to characterize that relationship.
This study was a retrospective review of 374 patients who had undergone a 3-column osteotomy (299 PSOs and 75 VCRs) and were part of a prospectively collected, multicenter adult spinal deformity database. The consecutively enrolled patients were drawn from 11 sites across the United States. Health-related QOL outcomes, according to the visual analog scale (VAS), Oswestry Disability Index (ODI), 36-Item Short-Form Health Survey (SF-36, physical component score [PCS] and mental component score), and Scoliosis Research Society-22 questionnaire (SRS), were evaluated preoperatively and 1 and 2 years postoperatively. Differences and correlations between patient age and HRQOL outcomes were investigated. Age groupings included young (age ≤ 45 years), middle aged (age 46–64 years), and elderly (age ≥ 65 years).
In patients who had undergone PSO, age significantly correlated (Spearman's correlation coefficient) with the 2-year ODI (ρ = 0.24, p = 0.0450), 2-year SRS function score (ρ = 0.30, p = 0.0123), and 2-year SRS total score (ρ = 0.30, p = 0.0133). Among all patients (PSO+VCR), the preoperative PCS and ODI in the young group were significantly higher and lower, respectively, than those in the elderly. Among the PSO patients, the elderly group had much greater improvement than the young group in the 1- and 2-year PCS, 2-year ODI, and 2-year SRS function and total scores. Among the VCR patients, the young age group had much greater improvement than the elderly in the 1-year SRS pain score, 1-year PCS, 2-year PCS, and 2-year ODI. There was no significant difference among all the age groups as regards the likelihood of reaching a minimum clinically important difference (MCID) within each of the HRQOL outcomes (p > 0.05 for all). Among the PSO patients, the elderly group was significantly more likely than the young to reach an MCID for the 1-year PCS (61% vs 21%, p = 0.0077) and the 2-year PCS (67% vs 17%, p = 0.0054), SRS pain score (57% vs 20%, p = 0.0457), and SRS function score (62% vs 20%, p = 0.0250). Among the VCR patients, the young group was significantly more likely than the elderly patients to reach an MCID for the 1-year (100% vs 20%, p = 0.0036) and 2-year (100% vs 0%, p = 0.0027) PCS scores and 1-year (60% vs 0%, p = 0.0173) and 2-year (70% vs 0%, p = 0.0433) SRS pain scores.
The PSO and VCR are not equivalent surgeries in terms of HRQOL outcomes and patient age. Among patients who underwent PSO, the elderly group started with more preoperative disability than the younger patients but had greater improvements in HRQOL outcomes and was more likely to reach an MCID at 1 and 2 years after treatment. Among those who underwent VCR, all had similar preoperative disabilities, but the younger patients had greater improvements in HRQOL outcomes and were more likely to reach an MCID at 1 and 2 years after treatment.