Different degeneration patterns of paraspinal muscles in degenerative lumbar diseases: a MRI analysis of 154 patients

Study design A retrospective study. Objective To evaluate the different degeneration patterns of paraspinal muscles in degenerative lumbar diseases and their correlation with lumbar spine degeneration severity. Summary of background data The degeneration characteristics of different paraspinal muscles in degenerative lumbar diseases remain unclear. Methods 78 patients diagnosed with single-level degenerative lumbar spondylolisthesis (DLS) and 76 patients with degenerative lumbar kyphosis (DLK) were included as DLS and DLK groups. Paraspinal muscle parameters of psoas major (PS), erector spinae (ES) and multifidus muscle (MF) were measured, including fatty infiltration (FI) and relative cross-sectional area (rCSA), namely the ratio of the paraspinal muscle CSA to the CSA of the vertebrae of the same segment. Sagittal parameters including lumbar lordosis (LL) and sagittal vertical axis (SVA) were measured. The paraspinal muscle parameters and ES/MF rCSA ratio were compared between the two groups. Paraspinal muscles parameters including rCSA and FI were also compared between each segments from L1 to L5 in both DLS and DLK groups. In order to determine the influence of sagittal spinal alignment on paraspinal muscle parameters, correlation analysis was conducted between the MF, ES, PS rCSA and FI and the LL in DLS and DLK group. Result MF atrophy is more significant in DLS patients compared with DLK. Also, MF fatty infiltration in the lower lumbar spine of DLS patients was greater compared to DLK patients. DLK patients showed more significant atrophy of ES and heavier ES fatty infiltration. MF FI was significantly different between all adjacent segments in both DLS and DLK groups. In DLS group, ES FI was significantly different between L2/L3 to L3/L4 and L4/L5 to L5/S1, while in DLK group, the difference of ES FI between all adjacent segments was not significant, and ES FI was found negatively correlated with LL. Conclusions Paraspinal muscles show different degeneration patterns in degenerative lumbar diseases. MF degeneration is segmental in both DLS and DLK patients, while ES degenerated diffusely in DLK patients and correlated with the severity of kyphosis. MF degeneration is more significant in the DLS group, while ES degeneration is more significant in DLK patients. MF is the stabilizer of the lumbar spine segments, while the ES tends to maintain the spinal sagittal balance.

Hounsfield unit value on CT as a predictor of cage subsidence following stand-alone oblique lumbar interbody fusion for the treatment of degenerative lumbar diseases

Background To investigate the correlation between vertebral Hounsfield unit (HU) values and cage subsidence in patients treated with stand-alone (SA) OLIF. Methods A retrospective review of collected data was performed on 76 patients who underwent SA OLIF. We utilized the HU value for lumbar bone mineral density (BMD) obtained on preoperative CT. The vertebral HU values of patients with subsidence were compared to those without subsidence. The correlation between cage subsidence and clinical score was investigated. Results Sixteen patients (21.1%) had at least radiographic evidence of interbody cage subsidence. The average cage subsidence was 2.5 ± 1.3 mm (range 0.9-4.8 mm). There were no significant differences in sex, BMI, preoperative diagnoses, or fused level (p > 0.05); however, there were significant differences between the cage subsidence group and the nonsubsidence group in age, average of the lowest T-score, and average HU value, including for the L1 vertebrae, L1-L4 horizontal plane, and L1-L4 sagittal plane (p < 0.05). The average HU value of the L1-L4 horizontal plane showed a more predictable AUC of 0.909 (95% CI, 0.834–0.984; P < 0.001) compared with the average of the lowest T-score following an AUC of 0.791 (95% CI, 0.674–0.909; P < 0.001). Based on logistic regression analysis, the average HU value of the L1-L4 horizontal plane (OR, 0.912; 95% CI, 0.861–0.966; P = 0.002) was an independent factor influencing cage subsidence. Conclusions Patients with lower average HU values of the lumbar vertebrae are at a much higher risk of developing cage subsidence after SA OLIF. Measurement of preoperative HU values on preexisting CT scans could be rapid, simple and feasible.

Endoscopic TLIF with Unilateral Pedicle Screw and Contralateral Translaminar Facet Screw Fixation : Technical Note and Early Outcomes

Study Design: Retrospective study.Objective：To evaluate outcomes and safety of endoscopic transforaminal lumbar interbody fusion (Endo-TLIF) for degenerative lumbar diseases.Summary of Background Data：There is no report about Endo-TLIF using unilateral pedicle screws and contralateral translaminar facet joint screw (UPS and TFS) fixation.Purpose: This paper evaluated the efficacy and safety of Endo-TLIF using UPS and TFS fixation in degenerative lumbar diseases.Methods:From August, 2018 to December, 2019, 21 patients with degenerative lumbar diseases were treated with Endo-TLIF. Clinical symptoms were evaluated at 1 month, 3 months, and the last follow-up after surgery. Outcomes were assessed by using the VAS back pain VAS leg pain, Oswestry disability index (ODI). Dural Sac Cross-sectional Area (DSCA), Foraminal Height (FH), Anterior Disc Height (ADH), Posterior Disc Height (PDH) and Lumbar Lordosis (LL).Results:The mean age of the cases was 62.9 years. The mean operation time was 198.7 min, the blood loss was 86.7 mL, and the length of incision was 5.7 cm. The mean time in bed was 34.3 hours, and the mean length of hospital stay was 15.1 days. The ODI scores improved from 64.1 to 13.3 (P < 0.05), the VAS score of back pain improved from 5.8 to 1.7 (P < 0.05), and the VAS score of leg pain improved from 6.2 to 1.6 (P < 0.05). ADH increased from 1.3 cm to 1.6 cm (P < 0.05), PDH increased from 0.7 cm to 1.0 cm (P < 0.05), FH increased from 1.7 cm to 2.0 cm (P < 0.05), and DSCA increased from 147 mm2 to 40 mm2 (P < 0.05). No serious complications occurred during the follow-up period.Conclusions:Endo-TLIF with UPS and TFS can improve the clinical symptoms of patients with degenerative lumbar diseases. The early curative effect was satisfactory.

Nano-Based Biomaterials as Drug Delivery Systems Against Osteoporosis: A Systematic Review of Preclinical and Clinical Evidence

Osteoporosis (OP) is one of the most significant causes of morbidity, particularly in post-menopausal women and older men. Despite its remarkable occurrence, the search for an effective treatment is still an open challenge. Here, we systematically reviewed the preclinical and clinical progress in the development of nano-based materials as drug delivery systems against OP, considering the effects on bone healing and regeneration, the more promising composition and manufacturing methods, and the more hopeful drugs and delivery methods. The results showed that almost all the innovative nano-based delivery systems developed in the last ten years have been assessed by preclinical investigations and are still in the preliminary/early research stages. Our search strategy retrieved only one non-randomized controlled trial (RCT) on oligosaccharide nanomedicine of alginate sodium used for degenerative lumbar diseases in OP patients. Further investigations are mandatory for assessing the clinical translation and commercial purposes of these materials. To date, the main limits for the clinical translation of nano-based materials as drug delivery systems against OP are probably due to the low reproducibility of the manufacturing processes, whose specificity and complexity relies on an adequate chemical, structural, and biomechanical characterization, as the necessary prerequisite before assessing the efficacy of a given treatment or process. Finally, an unsatisfactory drug-loading capacity, an uncontrollable release kinetic, and a low delivery efficiency also limit the clinical application.

Screw fixation failure after 360° fusion at the lumbar level

Aim: to identify possible predictors of screw loosening (SL) in patients after decompression and fusion at the lumbar level for degenerative spinal diseases. Methods. The data of patients with degenerative lumbar diseases who underwent primary decompression and fusion and who were re-hospitalized were analyzed. Clinical data (demography, characteristics of primary surgical procedures and characteristics of the perioperative period), results of radiological methods (presence and characteristics of resorption around screws, bone density (BMD) by densitometry and CT, intervertebral fusion grade and implant subsidence) were evaluated. Results. The study included 19 patients with SL and 37 patients without resorption, median age 59.1 [51.4; 63.1] years, men 20 (35.7%). When comparing patients with and without SL, there was no significant difference in gender, age, method of surgery, length of the fixation (p 0.05). According to CT scans, the bone density of the vertebrae between the groups did not differ significantly (p 0.05). In the group with SL, fusion failure was more common than in the group without SL (22.6% versus 20.7%), but the differences are not significant (p 0.05). In the intergroup comparison, it was determined that, in general, there were more complications in the group with SL than in the group without SL (p = 0.00015) due to the greater number of infectious complications (p = 0.00044). Also, patients with SL had a significantly longer duration of primary hospital stay (p = 0.000021). Conclusion. Patients with SL after primary surgery have a significantly longer hospital stay duration, mainly (45.8%) due to infectious complications. Patients with SL have comparable bone density in both the vertebral bodies and pedicles compared to patients without SL.