Spine

Diabetes mellitus as a risk factor for intervertebral disc degeneration: a critical review Abstract Purpose To examine to what extent diabetes mellitus (DM) is implicated as a distinct mechanism in intervertebral disc degeneration (IVDD). Methods The published clinical and laboratory data relevant to this matter are critically reviewed. A total of 12 clinical studies evaluate the association between DM and degenerative changes such as IVDD, spinal stenosis (SS) and IVD herniation. A total of 34 laboratory research papers evaluate the association between DM and IVDD. Results There are 7 studies that correlate DM with IVDD, 4 of them showing that DM is a significant risk factor for degeneration, and 3 of them failing to establish any association. Three studies demonstrate significant association between DM and SS. However, 2 of these studies also include patients with IVD herniation that failed to demonstrate any correlation with DM. Two other studies indicate a significant association between DM and lumbar disc herniation. Multiple different mechanisms, acting independently or interactively, cause tissue damage leading to IVDD including: microangiopathy of the subchondral vertebral endplate, cellular senescence, cell death (through apoptosis or autophagy), hyperglycaemia, advance glycation end products, adipokines, and cytokines (through oxidative, osmotic, and inflammatory mechanisms). Conclusion The clinical evidence is not consistent, but weakly supports the relationship between DM and IVDD. However, the laboratory studies consistently suggest that DM interferes with multipronged aberrant molecular and biochemical pathways that provoke IVDD. Taken as a whole, the strong laboratory evidence and the weak clinical studies implicate DM as a distinct contributing factor for IVDD. Graphic abstract These slides can be retrieved under Electronic Supplementary Material.

Diagnostic accuracy of whole spine magnetic resonance imaging in spinal tuberculosis validated through tissue studies Abstract Introduction Conventional diagnosis of spinal tuberculosis (TB) is based on a combination of clinical features, laboratory tests and imaging studies, since none of these individual diagnostic features are confirmatory. Despite the high sensitivity of MRI findings in evaluating spinal infections, its efficacy in diagnosing spinal TB is less emphasized and remains unvalidated through tissue studies. Methodology We reviewed consecutive patients evaluated for spondylodiscitis with documented clinical findings, MRI spine, and tissue analysis for histopathology, TB culture and genetic TB PCR. MRI features documented include location, contiguous/non-contiguous skip lesions, para/intraosseous abscess, subligamentous spread, vertebral collapse, abscess size/wall, disc involvement, end plate erosion and epidural abscess. Based on the results, patients were divided into two groups—CONFIRMED TB with positive culture/histopathology and NON-TB. The efficacy of MRI findings in accurately diagnosing spinal TB was compared between the two groups. Results Among 150 patients, 79 patients were TB positive, and 71 were TB negative. Three MRI parameters showed significant differences (p < 0.001), namely subligamentous spread (67/79, 84.8%), vertebral collapse > 50% (55/79, 69.6%) and large abscess collection with thin abscess wall (72/79, 91.1%) being strongly predictive of TB. Combination of MRI findings had a higher predictive value. 97.5% of TB positive patients had at least one of these three MRI features, 89.8% patients had any two and 58.2% had all three. Conclusion Our study validated different MRI findings with tissue studies and showed spinal infections with large abscess with thin wall, subligamentous spread of abscess and vertebral collapse were highly suggestive of spinal tuberculosis. Graphical abstract These slides can be retrieved under Electronic Supplementary Material.

Cobb angle measurement with a conventional convex echography probe and a smartphone Abstract Background context Serial X-rays are needed during the follow-up of adolescent idiopathic scoliosis. They are done every 6 or 3 months in cases of high risk of progression. Thanks to the advances in ultrasound techniques, deformity measurement systems free from ionizing radiations have been validated, although spinal surgeons did not use them routinely due to the need of special software. Objective The aim of our work is to assess the reproducibility and correlation of an ultrasound measuring system based on the positioning of the transverse processes. Study design Prospective, single center, randomized, triple blinded. Methods Two independent researchers trained in ultrasound examined the spinal deformities of 31 children. The measurements were compared against those performed with an X-ray by three scoliosis expert surgeons. Statistics were performed by an independent researcher. Parametric methods were used. Results We found a 95% [(0.91–0.97) p < 2.2e−16] correlation between the degree of scoliosis measured with the proposed ultrasound system and the 30 cm × 90 cm X-rays in standing position. There was an intra-observer reliability of 97% [r-squared = 0.97; CI 95% (0.95–0.98) p < 2.2e−16] and an inter-observer reliability of 95% [r-squared = 0.95; CI 95% (0.90–0.97) p < 2.2e−16]. Conclusions An approximation of the Cobb angle measure is possible with ultrasound by using the transverse processes as reference. This is a very rapid and simple system for assessing the principal spinal deformity measure in young people, although it does not allow estimating the associated axial or sagittal rotation. Graphic abstract These slides can be retrieved under Electronic Supplementary Material.

Correction to: Kinesiophobia modulates lumbar movements in people with chronic low back pain: a kinematic analysis of lumbar bending and returning movement In the figure 2, “CLBP Low fear” located at the right end of Time of Phase 1 is wrong. The correct statement is “CLBP High fear”. The complete correct figure 2 is given below.

The most appropriate cervical vertebra for the measurement of occipitocervical inclination parameter: a validation study of C3, C4, and C5 levels using multi-positional magnetic resonance imaging Abstract Purpose To evaluate which cervical level is the most appropriate level to measure occipitocervical inclination (OCI). Methods Sixty-two patients with multi-positional MRI: 24 males and 38 females, who had cervical lordosis and had a disk degeneration grade of 3 or less were included. We measured patient’s OCI at C3, C4, and C5, occipitocervical angle (OCA), occipitocervical distance (OCD), C2–7 angle, and cervical sagittal vertical axis (cSVA) in neutral, flexion, and extension position. The correlation between OCI and OCA, OCD, C2–7 angle, and cSVA on each cervical level in all three positions was tested using Pearson’s correlation coefficient test. The difference between OCIs at each cervical level was tested by Wilcoxon signed-rank test. p value of less than 0.05 was set as a statistically significant level. Results C5 OCI showed statistically significant correlation with OCA, OCD, C2–7 angle, and cSVA in all three positions (p < 0.05, r = 0.214–0.525). C3 OCI in flexion (p = 0.393, r = 0.081) and C4 OCI in neutral and flexion (neutral p = 0.275, r 0.104; flexion p = 0.987, r = 0.002) did not show significant correlation with C2–7 angle. There was a statistically significant difference between C3, C4, and C5 OCIs in neutral and extension position (p < 0.05). At the same time, OCI showed statistically strong correlation between adjacent cervical levels (p < 0.001, r = 0.627–0.822). Conclusion C5 cervical level is the most appropriate level for OCI measurement. OCI should be measured at the same cervical level at all time. C4 OCI can reliably substitute C5 OCI in case C5 which is invisible on radiographic image. Graphical abstract These slides can be retrieved under Electronic Supplementary Material.

Editorial

Impact of fusion for adolescent idiopathic scoliosis on lung volume measured with computed tomography Abstract Purpose Although lung volume (LV) can be measured directly by computed tomography (CT), the literature regarding CT-assessed LV in adolescent idiopathic scoliosis (AIS) patients is limited, and the influence of posterior spinal fusion with instrumentation (PSF) on LV has not been established. This study aimed to identify factors associated with decreased LV after PSF in AIS patients. Methods We retrospectively reviewed 111 consecutive AIS patients who were between 10 and 20 years of age and were treated by PSF at our facility. We assessed age at surgery, sex, height, body weight, Risser stage, Lenke classification, radiographic parameters, pulmonary function tests, and LV. Factors associated with a postoperative decrease in LV were identified by multivariable analysis. Results The mean total LV had increased at the 2-year follow-up, although marginally significant (p = .06), and there was a significant increase in the left LV (p = .01) but not the right LV (p = .25). We observed a postoperative reduction in total LV, defined as a total LV postoperative/preoperative ratio < 0.9, in 20 of the 111 patients (18.0%). Univariable analysis showed a significant correlation between ≥ 11 fusion levels and postoperative LV reduction (OR 3.11, 95% CI 1.13–8.57). This factor remained significant in the multivariable analysis, which yielded an adjusted OR of 2.82 (95% CI 1.01–7.93) for postoperative LV reduction in patients with ≥ 11 fusion levels. Conclusion Our data suggest that a longer fusion area is associated with postoperative LV reduction. Therefore, avoidance of a longer fusion area of ≥ 11 will be preferable for preserving LV. Graphical abstract These slides can be retrieved under Electronic Supplementary Material.

Management of a pseudarthrosis with sagittal malalignment in a patient with ochronotic spondyloarthropathy Abstract Purpose Ochronotic spondyloarthropathy is an uncommon disease, and its association to sagittal malalignment in the context of a pseudarthrosis has never been described. Methods We present the case of a 56-year-old female, who underwent previously L4L5 laminectomy for central canal stenosis and started later on to complain of progressively severe low back pain with a significant forward imbalance while walking. X-rays showed non-compensated sagittal malalignment due to thoracolumbar kyphosis, CT scan revealed multilevel central intradiscal calcifications with important vacuum disc at L4L5, and MRI showed T1 and T2 hypointensity signal at the same level with bone marrow oedema. Alkaptonuric ochronosis was suspected and confirmed by the presence of homogentisic acid in the urine, and the diagnosis of L4L5 pseudarthrosis with associated severe sagittal malalignment in the context of ochronotic spondyloarthropathy was established. Results The patient underwent surgery with a posterior-only approach with a long-segment pedicle screw construct from T10 to the pelvis with a 360° fusion with a cage at L4L5. Samples taken from the disc and ligaments confirmed the diagnosis of ochronotic spondyloarthropathy macroscopically and microscopically. She could walk on day 2 with a satisfactory clinical and radiological result at 2 years. Conclusion This is the first case in the literature to describe a post-laminectomy pseudarthrosis leading to a significant sagittal malalignment in a patient with ochronotic spondyloarthropathy. Management of such a case is challenging as the spine is partially ankylosed; therefore, a long construct is advisable to avoid ankylosing disorders related complications.

Differences in the interbody bone graft area and fusion rate between minimally invasive and traditional open transforaminal lumbar interbody fusion: a retrospective short-term image analysis Abstract Purpose We aimed to quantify the interbody bone graft area following transforaminal lumbar interbody fusion (TLIF) using traditional open and minimally invasive surgeries (MIS) and investigate their correlations with rates of fusion, complications, and clinical outcomes. Methods Patients undergoing TLIF of 1 or 2 levels between October 2015 and December 2016 were retrospectively included. Fusion and bone graft areas were assessed with computed tomography (CT) at 6 months postoperatively. The bone graft area ratio was defined as the bone graft area divided by the average endplate area. The distributions of bone graft area within the discs were also recorded. Clinical outcomes were assessed using the visual analog scale (VAS) and Oswestry Disability Index (ODI) questionnaires. Results In total, 77 disc levels in 57 patients were analyzed. The fusion rate was 79.1% in the open group and 82.4% in the MIS group (p = 0.718). Clinical outcomes of both groups improved significantly. Changes in VAS and ODI scores at 12 months postoperatively were comparable between groups. Bone graft area ratio was not significantly different between the two groups (open, 38 ± 10.8%; MIS, 38.1 ± 9.0%, p = 0.977). Analysis of bone graft distribution revealed that the contralateral-dorsal part of the disc had the lowest bone graft area. The bone graft area ratio was significantly higher in the solid union group (39.2 ± 10.4%) than in the non-solid union group (33.5 ± 6.4%, p = 0.048). Conclusions The fusion rates, bone graft area ratios, clinical outcomes, and complications were similar between MIS and open TLIF. Graphical abstract These slides can be retrieved under Electronic Supplementary Material.

Spinopelvic sagittal alignment of patients with transfemoral amputation Abstract Purpose This study aims to describe the spinopelvic sagittal alignment in transfemoral amputees (TFAs) from a radiologic study of the spine with a postural approach to better understand the high prevalence of low back pain (LBP) in this population. Methods TFAs underwent X-rays with 3-D reconstructions of the full spine and pelvis. Sagittal parameters were analyzed and compared to the literature. Differences between TFAs with and without LBP were also observed. Results Twelve subjects have been prospectively included (TFA-LBP group (n = 5) and TFA-NoP group (n = 7)). Four of the five subjects of the TFA-LBP group and two of the seven in TFAs-NoP group had an imbalanced sagittal posture, especially regarding the T9-tilt, significantly higher in the TFA-LBP group than in the TFA-NoP (p = 0.046). Eight subjects (6 TFA-NoP and 2 TFA-LBP) had abnormal low value of thoracic kyphosis (TK). Moreover, the mean angle of TK in the TFA-NoP group was lower than in the TFA-LBP group (p = 0.0511). Conclusion In the considered sample, TFAs often present a sagittal imbalance. A low TK angle seems to be associated with the absence of LBP. It can be hypothesized that this compensatory mechanism of the sagittal imbalance is the most accessible in this population. This study emphasizes the importance of considering the sagittal balance of the pelvis and the spine in patients with a TFA to better understand the high prevalence of LBP in this population. It should be completed by the analysis of the spinopelvic balance and the lower limbs in 3D. Graphical abstract These slides can be retrieved under Electronic Supplementary Material.