Lumbar Stabilization with DSS-HPS® System: Radiological Outcomes and Correlation with Adjacent Segment Degeneration

Arthrodesis has always been considered the main treatment of degenerative lumbar disease. Adjacent segment degeneration is one of the major topics related to fusion surgery. Non-fusion surgery may prevent this because of the protective effect of persisting segmental motion. The aims of the study were (1) to describe the radiological outcomes in the adjacent vertebral segment after lumbar stabilization with DSS-HPS® system and (2) to verify the hypothesis that this system prevents the degeneration of the adjacent segment. This is a retrospective monocentric analysis of twenty-seven patients affected by degenerative lumbar disease underwent spinal hybrid stabilization with the DSS-HPS® system between January 2016 and January 2019. All patients completed 1-year radiological follow-up. Preoperative X-rays and magnetic resonance images, as well as postoperative radiographs at 1, 6 and 12 months, were evaluated by one single observer. Pre- and post-operative anterior and posterior disc height at the dynamic (DL) and adjacent level (AL) were measured; segmental angle (SA) of the dynamized level were measured. There was a statistically significant decrease of both anterior (p = 0.0003 for the DL, p = 0.036 for the AL) and posterior disc height (p = 0.00000 for the DL, p = 0.00032 for the AL); there were a statistically significant variations of the segmental angle (p = 0.00000). Eleven cases (40.7%) of radiological progression of disc degeneration were found. The DSS-HPS® system does not seem to reduce progression of lumbar disc degeneration in a radiologic evaluation, both in the dynamized and adjacent level.

Contralateral radiculopathy after unilateral transforaminal lumbar interbody fusion: causes and prevention

Background Unilateral transforminal lumbar interbody fusion (TLIF) with a single cage can provide circumferential fusion and biomechanical stability. However, the causes and prevention of contralateral radiculopathy following unilateral TLIF remain unclear. Methods In total, 190 patients who underwent unilateral TLIF from January 2017 to January 2019 were retrospectively reviewed. Radiological parameters including lumbar lordosis, segmental angle, anterior disc height, posterior disc height (PDH), foraminal height (FH), foraminal width, and foraminal area (FA) were measured preoperatively and postoperatively. Preoperative and postoperative visual analog scale scores were also recorded. Results The incidence of contralateral radiculopathy after unilateral TLIF was 5.3% (10/190). The most common cause was contralateral foraminal stenosis. Unilateral TLIF could increase the lumbar lordosis, segmental angle, and anterior disc height but decrease the PDH, FA, and FH in patients with symptomatic contralateral radiculopathy. The intervertebral cage should be placed to cover the epiphyseal ring and cortical compact bone of the midline, and the disc height can be increased to enlarge the contralateral foramen. Conclusion The most common cause of contralateral radiculopathy is contralateral foraminal stenosis. Careful preoperative planning is necessary to achieve satisfactory outcomes. Improper unilateral TLIF will decrease the PDH, FA, and FH, resulting in contralateral radiculopathy.

Risk Factors for Dysphagia after Anterior Cervical Discectomy and Fusion with the Zero-P Implant system: A Study with Minimum of 2 Years Follow-up

ObjectiveDysphagia is one of the most common complications after anterior cervical spine surgery. The study aimed to evaluate the risk factors for dysphagia after anterior cervical discectomy and fusion (ACDF) with the Zero-P Implant System by multidimensional analysis and investigated the predictive values of these risk factors for dysphagia.MethodsA retrospective analysis of 260 patients who underwent ACDF with the Zero-P Implant System and had at least 2 year of follow-up ware performed. All patients were divided into a non-dysphagia group and a dysphagia group. Sex, age, body mass index (BMI), intraoperative time, estimated blood loss, diabetes mellitus, hypertension, smoking, alcohol consumption, prevertebral soft-tissue thickness, the levels of surgery, O-C2 angle, C2–7 angle, T1 slope and segmental angle were analyzed. Chi-square test and logistic regression were performed to analyze the predictive value of each dimension for dysphagia.ResultsIn total, the non-dysphagia group comprised 70 patients and the dysphagia group comprised 190 patients. Chi-square test results indicated that number of operated levels, operation time dT1 slope, dO-C2 angle, dC2–7 angle, segmental angle and dPSTT were associated with a high incidence of dysphagia. Multivariate logistic regression analysis showed that number of operated levels, operation time, dC2–7 angle and dPSTT were significantly associated with postoperative dysphagia.ConclusionsNumber of operated levels, operation time, dC2–7 angle and dPSTT were significantly associated with postoperative dysphagia. In additionally, sufficient preoperative preparation, evaluation combining with proficient and precise treatment measures are suggested to reduce the incidence of postoperative dysphagia when ACDF is performed.

Risk Factors for Dysphagia After Anterior Cervical Discectomy and Fusion With the Zero-P Implant System: a Retrospective Study With Minimum of 2 Years Follow-up

Background: Dysphagia is one of the most common complications after anterior cervical spine surgery. The study aimed to evaluate the risk factors for dysphagia after anterior cervical discectomy and fusion (ACDF) with the Zero-P Implant System by multidimensional analysis and investigated the predictive values of these risk factors for dysphagia. Methods: A retrospective analysis of 260 patients who underwent ACDF with the Zero-P Implant System and had at least 2 year of follow-up ware performed. All patients were divided into a non-dysphagia group and a dysphagia group. Sex, age, body mass index (BMI), intraoperative time, estimated blood loss, diabetes mellitus, hypertension, smoking, alcohol consumption, prevertebral soft-tissue thickness, the levels of surgery, O-C2 angle, C2–7 angle, T1 slope and segmental angle were analyzed. Chi-square test and logistic regression were performed to analyze the predictive value of each dimension for dysphagia. Results: In total, the non-dysphagia group comprised 170 patients and the dysphagia group comprised 90 patients. Chi-square test results indicated that number of operated levels, operation time dT1 slope, dO-C2 angle, dC2–7 angle, segmental angle and dPSTT were associated with a high incidence of dysphagia. Multivariate logistic regression analysis showed that number of operated levels, operation time, dC2–7 angle and dPSTT were significantly associated with postoperative dysphagia.Conclusions: Number of operated levels, operation time, dC2–7 angle and dPSTT were significantly associated with postoperative dysphagia. In additionally, sufficient preoperative preparation, evaluation combining with proficient and precise treatment measures are suggested to reduce the incidence of postoperative dysphagia when ACDF is performed.

Local Autograft Versus Iliac Crest Bone Graft PSF-Augmented TLIF in Low-Grade Isthmic and Degenerative Lumbar Spondylolisthesis

Study Design: Prospective randomized controlled cohort study. Objective: To compare the outcome of local autograft versus iliac crest bone graft (ICBG) stand-alone transforaminal lumbar interbody fusion (TLIF) in lumbar spondylolisthesis. Methods: One hundred eight patients with low-grade single-level spondylolisthesis underwent operation with pedicular screw fixation (PSF)-augmented stand-alone TLIF. Patients were randomly divided into groups according to bone graft: group I, autograft group; and group II, ICBG group, with 54 patients each. Fifty-nine patients had isthmic spondylolisthesis and 49 had degenerative spondylolisthesis. Clinical outcome parameters included Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and patient’s satisfaction, while the radiological parameters included fusion rate, slip reduction, segmental angle, and disc height. The mean follow-up period was 38 ± 19 months, with a minimum 24 of months. Results: The preoperative VAS of back pain improved from 8 ± 3.1 to 3.4 ± 2.9 and from 8 ± 3.2 to3.6 ± 2.6 in group I and group II, respectively. The preoperative ODI improved from 41.4 ± 8 to 12.3 ± 7 and from 39 ± 9 to 13 ± 8 in group I and group II, respectively. The fusion rate was 93% in group I and 94.5% in group II. The percentage of slip was reduced from 26.7 ± 7.1% to 16.5 ± 6.1% in group I and from 27.4 ± 8.25 to 15.8 ± 5.2% in group II. Intervertebral disc height increased from 25.27 ± 14.62 to 46.38 ± 15.41 in group I and from 22.29 ± 13.72 to 45.15 ± 16.77 in group II. Segmental angle improved from 10.5 ± 8.1° to 16.7 ± 5.4° in group I and from 11.6 ± 5.3° to 15.9 ± 6.2° in group II. There was no significant difference of the above-mentioned parameters between the 2 groups. Conclusion: Patients with single-level low-grade spondylolisthesis can be effectively treated with PSF-augmented stand-alone TLIF using either local autograft or ICBG with no outcome differences between the 2 groups.

Does the Position of Cage Affect the Clinical Outcome of Lateral Interbody Fusion in Lumbar Spinal Stenosis?

Study Design: A retrospective study. Objective: This study aims to identify the ideal cage position in lateral lumbar interbody fusion (LLIF) and to investigate if the posterior instrumentation would affect the indirect decompression. Methods: Patients underwent 2-stage surgeries: stage I was LLIF and stage II was percutaneous pedicle screws fixation after 1 week. Anterior disc height (ADH), posterior disc height (PDH), left and right foraminal height (FH), and segmental angle (SA) were measured on lateral computed tomography reconstructions. The cross-sectional area of the thecal sac (CSA) was determined by the outlined area of the thecal sac on a T2-weighted axial magnetic resonance imaging. The patients were subgroups according to the cage position: the anterior (cage located at the anterior 1/3 of disc space) and posterior groups (cage located at the posterior 2/3 of disc space). P values <.05 were considered significant. Results: This study included 46 patients and 71 surgical levels. After stage I LLIF, significant increase in ADH, PDH, bilateral FH was found in both 2 subgroups, as well as the CSA (all Ps < .01). SA increased 2.84° ± 3.2° in the anterior group after stage I LLIF and increased 0.81° ± 3.1° in the posterior group ( P = .013). After stage II surgery, SA was similar between the anterior and posterior groups ( P = .20). Conclusion: The anteriorly placed cage may provide better improvement of anterior disc height and segmental angle after stand-alone LLIF surgery. After the second stage posterior instrumentation, the cage position would not affect the segmental angle or foraminal height.

Clinical Results Of A Lamina With Spinous Process And An Iliac Graft As Bone Grafts In The Surgical Treatment Of Single-Segment Lumbar Pyogenic Discitis: A Retrospective Cohort Study

Background: A retrospective study investigated and compared the results of a lamina withspinous process (LSP) and an iliac graft (IG) as bone grafts in single-segment lumbar pyogenic discitis (LPD) through one-stage-posterior-only approach with radical debridement and internal instrumentation.Methods: Data from 37 patients were reviewed. A LSP was placed in 17 patients (group A), and an IG was implemented in 20 patients (group B). The surgery time, surgery hemorrhage, hospital stay, drainage, and follow-up (FU) were reviewed. The visual analogue scale (VAS), Oswestry Disability Index (ODI), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) level, segmental angle, intervertebral height and bony fusion time were compared preoperatively and at the final FU.Results: All patients were followed-up for a mean of 27.94±2.35 months in group A and 30.29±1.89 months in group B, without a difference. The mean age was younger in group A than in group B (P<0.05). The surgery time, surgery hemorrhage, and hospitalization cost were lower in group A than in group B (P<0.05), except for the hospital stay and drainage time. Fever occurred in 10 patients in group A and 12 patients in group B. The ESR, CRP level, and VAS and ODI scores were significantly decreased, and there were no significant differences between the groups at the final FU. The distribution of bacterial agents in blood culture was 1 case of Aerobacter cloacae, 2 of Staphylococcus aureus, 2 of Escherichia coli, and 1 of Streptococcus viridis in group A and 1 of S. aureus，1 of Staphylococcus warneri and 2 of Klebsiella pneumoniae in group B. Pyogenic infection was observed in the pathological findings of all patients. No significant difference was found in the mean segmental angle or mean intervertebral height preoperation and at the final FU between the groups.Conclusion: The use of LSP as a new bone graft is reliable, safe, and effective for surgical management for the LPD while surgery is proposed as a good management strategy for LPD in carefully selected patients.

Can posterior stand-alone expandable cages safely restore lumbar lordosis? A minimum 5-year follow-up study

Background: Lumbar lordosis (LL) can be restored and screw-related complications may be avoided with the stand-alone expandable cage method. However, the long-term spinopelvic profile changes and safety remain unknown. We aimed to elucidate the long-term radiologic outcomes and safety of this technique. Methods: Data from a total of 69 patients who underwent multi-level stand-alone expandable cage fusion and 80 patients who underwent screw-assisted fusion between February 2007 and December 2012, with at least 5 years of follow-up, were retrospectively analyzed. Segmental angle and translation, short and whole LL, pelvic incidence, pelvic tilt, sacral slope (SS), sagittal vertical balance, thoracic kyphosis, and presence of subsidence, pseudoarthrosis, retropulsion, cage breakage, proximal junctional kyphosis (PJK), and screw malposition were assessed. The relationship between local and spinopelvic effects was investigated. The implant failure rate was considered a measure of procedure effectiveness and safety. Results: The stand-alone expandable cage fusion group showed shorter operative times, a lower rate of PJK, and better improvements in segmental angles than the control group, and there was a positive correlation with LL. However, the whole LL was not restored; the SS significantly increased; and subsidence, pseudoarthrosis, and retropulsion rates were significantly higher than those in the control group. Conclusions: Stand-alone expandable cage fusion can restore local lordosis, however, global sagittal balance was not restored. Furthermore, implant safety still has not been proven.

Can posterior stand-alone expandable cages safely restore lumbar lordosis? A minimum 5-year follow-up study

Background Lumbar lordosis (LL) can be restored and screw-related complications may be avoided with the stand-alone expandable cage method. However, the long-term spinopelvic profile changes and safety remain unknown. We aimed to elucidate the long-term radiologic outcomes and safety of this technique. Methods Data from a total of 69 patients who underwent multi-level stand-alone expandable cage fusion and 80 patients who underwent screw-assisted fusion between February 2007 and December 2012, with at least 5 years of follow-up, were retrospectively analyzed. Segmental angle and translation, short and whole LL, pelvic incidence, pelvic tilt, sacral slope (SS), sagittal vertical balance, thoracic kyphosis, and presence of subsidence, pseudoarthrosis, retropulsion, cage breakage, proximal junctional kyphosis (PJK), and screw malposition were assessed. The relationship between local and spinopelvic effects was investigated. The implant failure rate was considered a measure of procedure effectiveness and safety. Results The stand-alone expandable cage fusion group showed shorter operative times, a lower rate of PJK, and better improvements in segmental angles than the control group, and there was a positive correlation with LL. However, the whole LL was not restored; the SS significantly increased; and subsidence, pseudoarthrosis, and retropulsion rates were significantly higher than those in the control group. Conclusions Stand-alone expandable cage fusion can restore local lordosis, however, global sagittal balance was not restored. Furthermore, implant safety still has not been proven.