Background: Our understanding of the relationship between sagittal alignment and mechanical complications is evolving. In normal spines, the L1-pelvic angle (L1PA) accounts for the magnitude and distribution of lordosis and is strongly associated with pelvic incidence (PI), and the T4-pelvic angle (T4PA) is within 4° of the L1PA. We aimed to examine the clinical implications of realignment to a normal L1PA and T4-L1PA mismatch. Methods: A prospective multicenter adult spinal deformity registry was queried for patients who underwent fixation from the T1-T5 region to the sacrum and had 2-year radiographic follow-up. Normal sagittal alignment was defined as previously described for normal spines: L1PA = PI × 0.5 − 21°, and T4-L1PA mismatch = 0°. Mechanical failure was defined as severe proximal junctional kyphosis (PJK), displaced rod fracture, or reoperation for junctional failure, pseudarthrosis, or rod fracture within 2 years. Multivariable nonlinear logistic regression was used to define target ranges for L1PA and T4-L1PA mismatch that minimized the risk of mechanical failure. The relationship between changes in T4PA and changes in global sagittal alignment according to the C2-pelvic angle (C2PA) was determined using linear regression. Lastly, multivariable regression was used to assess associations between initial postoperative C2PA and patient-reported outcomes at 1 year, adjusting for preoperative scores and age. Results: The median age of the 247 included patients was 64 years (interquartile range, 57 to 69 years), and 202 (82%) were female. Deviation from a normal L1PA or T4-L1PA mismatch in either direction was associated with a significantly higher risk of mechanical failure, independent of age. Risk was minimized with an L1PA of PI × 0.5 − (19° ± 2°) and T4-L1PA mismatch between −3° and +1°. Changes in T4PA and in C2PA at the time of final follow-up were strongly associated (r² = 0.96). Higher postoperative C2PA was independently associated with more disability, more pain, and worse self-image at 1 year. Conclusions: We defined sagittal alignment targets using L1PA (relative to PI) and the T4-L1PA mismatch, which are both directly modifiable during surgery. In patients undergoing long fusion to the sacrum, realignment based on these targets may lead to fewer mechanical failures. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Study Design.: A retrospective review. Objective.: This study aimed to determine the factors associated with malpractice litigation in cases involving spine surgery in the United States. Summary of Background Data.: Medical malpractice is of substantial interest to the medical community due to concerns of increased health care costs and medical decision-making for the sole purpose of reducing legal liability. Methods.: The Westlaw online legal database (Thomson Reuters, New York, NY) was searched for verdict and settlement reports pertaining to spine surgery from 2010 to 2015. Data were collected regarding type of procedure, patient age and gender, defendant specialty, outcome, award, alleged cause of malpractice, and factors involved in the plaintiff's decision to file. Initial search queried 187 cases, after which exclusion criteria were applied to eliminate duplicates and cases unrelated to spine surgery, yielding a total of 98 cases for analysis. Results.: The verdict was in favor of the defendant in 62 cases (63.3%). Neurosurgeons and orthopedic surgeons were the most common defendants in 29 (17.3%) and 40 (23.8%) of the cases, respectively. A perceived lack of informed consent was noted as a factor in 24 (24.4%) of the cases. A failure to diagnose or a failure to treat was noted in 31 (31.6%) and 32 (32.7%) cases, respectively. Median payments for plaintiff verdicts were nearly double those of settlements ($2,525,000 vs. $1,300,000). A greater incidence of plaintiff verdicts was noted in cases in which a failure to treat (P < 0.05) was cited, a patient death occurred (P < 0.05), or an emergent surgery had been performed (P < 0.01). Conclusion.: Overall, physicians were not found liable in the majority of spine surgery malpractice cases queried. Level of Evidence: 4

OBJECTIVE: Stand-alone lateral lumbar interbody fusion (LLIF) is a useful minimally invasive approach for select spinal disorders, but implant subsidence may occur in up to 30% of patients. Previous studies have suggested that wider implants reduce the subsidence rate. This study aimed to evaluate whether a mismatch of the endplate and implant area can predict the rate and grade of implant subsidence.METHODS: The authors conducted a retrospective review of prospectively collected data on consecutive patients who underwent stand-alone LLIF between July 2008 and June 2015; 297 patients (623 surgical levels) met inclusion criteria. Imaging studies were examined to grade graft subsidence according to Marchi criteria. Thirty patients had radiographic evidence of implant subsidence. The endplates above and below the implant were measured.RESULTS: A total of 30 patients with implant subsidence were identified. Of these patients, 6 had Marchi grade 0, 4 had grade I, 12 had grade II, and 8 had grade III implant subsidence. There was no statistically significant correlation between the endplate-implant area mismatch and subsidence grade or incidence. There was also no correlation between endplate-implant width and length mismatch and subsidence grade or incidence. However, there was a strong correlation between the usage of the 18-mm-wide implants and the development of higher-grade subsidence (p = 0.002) necessitating surgery. There was no significant association between the degree of mismatch or Marchi subsidence grade and the presence of postoperative radiculopathy. Of the 8 patients with 18-mm implants demonstrating radiographic subsidence, 5 (62.5%) required reoperation. Of the 22 patients with 22-mm implants demonstrating radiographic subsidence, 13 (59.1%) required reoperation.CONCLUSIONS: There was no correlation between endplate-implant area, width, or length mismatch and Marchi subsidence grade for stand-alone LLIF. There was also no correlation between either endplate-implant mismatch or Marchi subsidence grade and postoperative radiculopathy. The data do suggest that the use of 18-mm-wide implants in stand-alone LLIF may increase the risk of developing high-grade subsidence necessitating reoperation compared to the use of 22-mm-wide implants.