Effect of surgical experience and spine subspecialty on the reliability of the {AO} Spine Upper Cervical Injury Classification System

OBJECTIVE The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (< 5 years, 5–10 years, 10–20 years, and > 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and "other" surgery). METHODS A total of 11,601 assessments of upper cervical spine injuries were evaluated based on the AO Spine Upper Cervical Injury Classification System. Reliability and reproducibility scores were obtained twice, with a 3-week time interval. Descriptive statistics were utilized to examine the percentage of accurately classified injuries, and Pearson’s chi-square or Fisher’s exact test was used to screen for potentially relevant differences between study participants. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility. RESULTS The intraobserver reproducibility was substantial for surgeon experience level (< 5 years: 0.74 vs 5–10 years: 0.69 vs 10–20 years: 0.69 vs > 20 years: 0.70) and surgical subspecialty (orthopedic spine: 0.71 vs neurosurgery: 0.69 vs other: 0.68). Furthermore, the interobserver reliability was substantial for all surgical experience groups on assessment 1 (< 5 years: 0.67 vs 5–10 years: 0.62 vs 10–20 years: 0.61 vs > 20 years: 0.62), and only surgeons with > 20 years of experience did not have substantial reliability on assessment 2 (< 5 years: 0.62 vs 5–10 years: 0.61 vs 10–20 years: 0.61 vs > 20 years: 0.59). Orthopedic spine surgeons and neurosurgeons had substantial intraobserver reproducibility on both assessment 1 (0.64 vs 0.63) and assessment 2 (0.62 vs 0.63), while other surgeons had moderate reliability on assessment 1 (0.43) and fair reliability on assessment 2 (0.36). CONCLUSIONS The international reliability and reproducibility scores for the AO Spine Upper Cervical Injury Classification System demonstrated substantial intraobserver reproducibility and interobserver reliability regardless of surgical experience and spine subspecialty. These results support the global application of this classification system

Selective thoracic fusion provides similar health-related quality of life but can cause more lumbar disc and facet joint degeneration: A comparison of adolescent idiopathic scoliosis patients with normal population 10 years after surgery

Objectives To evaluate the long-term behavior of the lumbar curve in patients with adolescent idiopathic scoliosis treated with selective thoracic fusion and to assess the clinical and radiologic outcomes in this fusion group compared with an age- and gender-matched group. Summary of Background Data Selective thoracic fusion for the treatment of adolescent idiopathic scoliosis (AIS) preserves lumbar motion segments but leaves a residual deformity. By avoiding fusion of the lumbar spine, a greater mobility may be preserved, which may be an advantage in long-term follow-up in terms of degenerative changes in unfused segments. Methods Group A included 25 AIS patients with mean a age of 23.8 years and a mean 11.4 years of follow-up. Group B included 30 age- and gender-matched subjects without any deformity. Preoperative, postoperative, and follow-up radiographs were reviewed. All patients had MRIs taken at the final follow-up in order to evaluate disc degeneration (DD) and facet joint degeneration (FJD) at the unfused lumbar spine. Clinical evaluation was done by using Scoliosis Research Society-22R, Oswestry Disability Index, and numerical rating scale. Results Sagittal and coronal balance and lowest instrumented vertebra disc angulation were stable over time. Mean grading of lumbar DD was 2.16 (2-4) in Group A and 1.86 (1-3) in Group B. Lumbar FJDs were 2.05 (1-4) in Group A and 1.60 (1-3) in Group B. There was significant difference between the two groups for DD except for the L4-L5 level (p =.26). FJD was significantly higher in the L1-L2 and L2-L3 levels (L1-L2, p =.002, L2-L3, p =.002) but not for the other levels. Outcome scores were similar without significant differences between the two groups (p >.05). Conclusion Selective thoracic fusion provides satisfactory outcomes at more than 10 years of follow-up. Our study demonstrated a moderate increase in the rate of disc degeneration in the unfused segments. Facet joint degeneration was significant at the upper two levels adjacent to the lowest instrumented vertebra. © 2015 Scoliosis Research Society

Does It Make a Difference to Stop Fusion at L3 Versus L4 in Terms of Disc and Facet Joint Degeneration: An MRI Study with Minimum 5 Years Follow-up

Objectives To compare the functional outcomes of patients with idiopathic scoliosis who had surgical correction and fusion with all pedicle screw construct down to L3 or L4 and to evaluate whether saving a mobile lumbar motion segment distally would demonstrate any difference in terms of disc degeneration (DD) and facet joint degeneration (FJD) after minimum 5 years follow-up. Summary of Background Data Selection of lowest instrumented vertebra (LIV) is often difficult when lumbar curve was included into the fusion (L3 vs L4). Saving L4 is believed to be beneficial for preserving motion and preventing degeneration of unfused lumbar spine. Methods The L3 group included 21 patients (mean age of 21.4) and L4 group included 16 patients (mean age 22.9). Control group included 30 healthy individuals with no spinal deformities (mean age of 23.8). Follow-up lumbar magnetic resonance images (MRIs) were evaluated for each patient in terms of DD and FJD. Clinical evaluation was done by using the Scoliosis Research Society-22r, Oswestry Disability Index, and Numeric Rating Scale. Results Mean follow-up period was 7.4 (5-10) years in the L3 group and 9 (5-17) years in L4 group. Average correction rates for lumbar curve magnitudes were 78% in the L3 group and 79% in the L4 group, with no significant correction loss at the final follow-up. There was no statistical difference for DD in all groups (p >.05). FJD was significantly greater in both L3 and L4 groups compared to the control group (p .05). Conclusion Spinal balance and corrections remained stable, without showing any decompensation over time. This midterm MRI study demonstrated similar disc and facet degeneration rates for L3 and L4 groups. FJD at the upper two levels adjacent to the LIV was significant for both surgically treated groups. Clinical outcome scores were similar for all groups at minimum 5 years follow-up. © 2016 Scoliosis Research Society

The role of routine magnetic resonance imaging in the preoperative evaluation of adolescent idiopathic scoliosis

The routine use of magnetic resonance imaging (MRI) in adolescent idiopathic scoliosis remains controversial, and current indications for MRI in idiopathic scoliosis vary from study to study. The purpose of this study was to demonstrate the prevalence of neural axis malformations and the clinical relevance of routine MRI studies in the evaluation of patients with adolescent idiopathic scoliosis undergoing surgical intervention without any neurological findings. A total of 249 patients with a diagnosis of idiopathic scoliosis were treated surgically between the years 2002 and 2007. A routine whole spine MRI analysis was performed in all patients. On the preoperative clinical examination, all patients were neurologically intact. There were 20 (8%) patients (3 males and 17 females) who had neural axis abnormalities on MRI. Three of those 20 patients needed additional neurosurgical procedures before corrective surgery; the remaining underwent corrective spinal surgery without any neurosurgical operations. Magnetic resonance imaging may be beneficial for patients with presumed idiopathic scoliosis even in the absence of neurological findings and it is ideally performed from the level of the brainstem to the sacrum