Decrease In Disc Height Research Articles

Efficacy comparison of robot-assisted versus freehand fluoroscopy-assisted minimally invasive transforaminal lumbar interbody fusion for degenerative lumbar spinal diseases

Objective: To compare the clinical and radiographic outcomes between robot-assisted minimally invasive transforaminal lumbar interbody fusion (RA MIS-TLIF) and fluoroscopy-assisted MIS-TLIF (FA MIS-TLIF) in patients with degenerative lumbar spinal diseases. Methods: The clinical data of 114 patients with lumbar degenerative diseases who underwent MIS-TLIF in Qilu Hospital of Shandong University from January 2019 to March 2022 were analyzed retrospectively. Fifty-eight patients underwent RA MIS-TLIF (robot group) and 56 patients received FA MIS-TLIF (freehand group). There were 16 males and 42 females in the robot group, with a mean age of (56.7±8.1) years. And there were 19 males and 37 females in the freehand group, with a mean age of (57.2±8.6) years. The clinical outcome parameters were the visual analog scale (VAS) of pain, Oswestry Disability Index (ODI) score, operative time, number of intraoperative fluoroscopies, blood loss, postoperative hospital stay and complications. The radiographic change measures were the accuracy of screw placement, facet joint violation (FJV), fusion status, and change in disc height at the proximal adjacent segment. All the patients were followed-up for 2-5 years. Results: There was no significant differences in the VAS and ODI scores, blood loss, or postoperative hospital stay between the two groups (all P>0.05). The operative time was longer in robot group than freehand group [(158.5±12.1) min vs (146.4±15.4) min, P<0.001]. There was no significant difference in the number of intraoperative fluoroscopies for patients between robot group and freehand group (P>0.05). The number of intraoperative fluoroscopies for the surgeon was significantly lower in robot group than freehand group (13.8±3.9 vs 74.7±6.8, P<0.001). The rate of a perfect screw position (grade A) was higher in robot group than freehand group [87.5%(203/232) vs 70.1%(157/224), P<0.001]. However, there was no significant difference in the proportion of clinically acceptable screws (grades A and B) between the two groups [98.3%(228/232) vs 96.9%(217/224), P=0.330]. The FJV grade was significantly higher in freehand group than robot group (0.43±0.68 vs 0.13±0.43, P<0.001). During at 2-year postoperative follow-up, there was no significant difference in the fusion status between the two groups (P>0.05); however, the decrease in disc height at the proximal adjacent segment was significantly less in robot group than freehand group [(0.63±0.38) mm vs (0.92±0.35) mm, P=0.001]. In the robotic group, a pedicle screw penetrated the outer wall of the vertebral pedicle in one patient, which was adjusted during surgery. In the freehand group, two screws were inserted too deeply and penetrated the anterior cortex, resulting in mild abdominal discomfort postoperatively, which resolved by the third day after surgery. Conclusions: Robot-assisted percutaneous pedicle screw placement is a safer and more accurate alternative to conventional freehand fluoroscopy-assisted pedicle screw insertion in MIS-TLIF. Compared with freehand MIS-TLIF, robot-assisted MIS-TLIF increases the operation time, but the accuracy of screw placement is higher, and the intraoperative radiation dose and the degree of adjacent segment degeneration are reduced.

Papain Injection Creates a Nucleotomy-like Cavity for Testing Gels in Intervertebral Discs.

Biomaterials, such as hydrogels, have an increasingly important role in the development of regenerative approaches for the intervertebral disc. Since animal models usually resist biomaterial injection due to high intradiscal pressure, preclinical testing of the biomechanical performance of biomaterials after implantation remains difficult. Papain reduces the intradiscal pressure, creates cavities within the disc, and allows for biomaterial injections. But papain digestion needs time, and cadaver experiments that are limited to 24 h for measuring range of motion (ROM) cannot not be combined with papain digestion just yet. In this study, we successfully demonstrate a new organ culture approach, facilitating papain digestion to create cavities in the disc and the testing of ROM, neutral zone (NZ), and disc height. Papain treatment increased the ROM by up to 109.5%, extended NZ by up to 210.9%, and decreased disc height by 1.96 ± 0.74 mm. A median volume of 0.73 mL hydrogel could be injected after papain treatment, and histology revealed a strong loss of proteoglycans in the remaining nucleus tissue. Papain has the same biomechanical effects as known from nucleotomies or herniations and thus creates a disc model to study such pathologies in vitro. This new model can now be used to test the performance of biomaterials.

Disc Height and Angle Changes on Radiographs and Magnetic Resonance Imaging after Anterior or Posterior Percutaneous Endoscopic Cervical Discectomy.

Objectives: Cervical disc herniation (CDH) leads to pain, numbness, and potential disability. Percutaneous endoscopic cervical discectomy (PECD) offers an anterior or posterior approach. This study aims to compare postoperative disc height and angle changes one year after PECD, considering both approaches. Methods: We retrospectively reviewed the data from patients with CDH who underwent PECD from October 2017 to July 2022. Cervical disc height was measured using the preoperative and one-year postoperative magnetic resonance imaging (MRI) examinations. Lordotic angle (LA), global alignment angle (GAA), segmental alignment angle (SAA), and slippage distance (SD) at the surgical level were measured on radiographs in the neutral, flexion, and extension positions. Results: Thirty-eight patients who underwent posterior PECD (PPECD) and five patients who underwent anterior PECD (APECD) were included in the evaluation. The mean age of the patients was 47.4 years (range: 29-69 years). There was a significant difference in the preoperative and one-year postoperative GAA and SAA in extension in the PPECD group (p = 0.003 and 0.031, respectively). The mean decreased disc height one-year postoperative was 1.30 mm in the APECD group and 0.3 mm in the PPECD group by MRI. A significant disc height decrease was observed in the APECD group (p < 0.001). Conclusions: Treating CDH with PPECD or APECD is feasible, as it can relieve symptoms and reduce disability. Stability remained unaffected during the first year after surgery, even though there was an increase in angulation during extension. Despite a significant decrease in disc space following APECD, patients reported significant symptom improvement and no new symptoms.

Study and analysis of the correlation between lumbar spondylolisthesis and Modic changes.

This study aimed to explore the risk factors of Modic changes in lumbar spondylolisthesis. The distribution of Modic changes in different types of lumbar spondylolisthesis, degree of spondylolisthesis, and degree of intervertebral disc degeneration in patients with lumbar spondylolisthesis was observed and analyzed. Statistical analysis was conducted to assess whether intervertebral disc degeneration, local mechanical changes, etc. affect the occurrence of Modic changes. The risk factors of Modic changes in lumbar spondylolisthesis were further illustrated. The age in the lumbar spondylolisthesis with Modic changes group was younger than that in the lumbar spondylolisthesis without Modic changes group, and the bone mineral density was better in the lumbar spondylolisthesis with Modic changes group than that in the lumbar spondylolisthesis without Modic changes group, P < 0.05. The two groups statistically differed in intervertebral disc height (IDH) and disc angle on magnetic resonance imaging (MRI). In the classification of Modic changes, the incidence of type II was the highest. The incidence of Modic changes is higher in isthmic spondylolisthesis than in degenerative spondylolisthesis. With the aggravation of lumbar spondylolisthesis and intervertebral disc degeneration, the incidence of Modic changes gradually increased. Modic changes are most commonly seen in both the upper and lower endplates. Logistic regression analysis showed that the occurrence of Modic changes in lumbar spondylolisthesis was significantly correlated with IDH, disc angle on MRI, type of spondylolisthesis, degree of spondylolisthesis, and degree of intervertebral disc degeneration, P < 0.05. The occurrence of Modic changes is related to the type of spondylolisthesis, the degree of spondylolisthesis, the degree of disc degeneration, the decrease of intervertebral disc height, and local stress angulation.

Morphological changes after open lumbar microdiscectomy at 2-year follow-up.

It is known that a possible decrease in disc height (DH) and foraminal size after open lumbar microdiscectomy (OLM) may cause pain in the long term. However, there is still insufficient information about the short- or long-term pathoanatomical and morphological effects of microdiscectomy. For example, the exact temporal course of the change in DH is not well known. The purpose of this study was to examine morphological changes in DH and foramen dimensions after OLM. In patients who underwent OLM for single-level lumbar disc herniation, MRI scans were obtained before surgery, and at an average of two years after surgery. In addition to DH measurements, foraminal area (FA), foraminal height (FH), superior foraminal width (SFW), and inferior foraminal width (IFW), were measured bilaterally. A postoperative increase in DH was observed at all vertebral levels, with an average of 5.5%. The mean right FHs were 15.3mm and 15.7mm before and after surgery, respectively (p= 0.062), while the left FHs were 14.8mm and 15.8mm before and after surgery (p= 0.271). The mean right SFW was 5.4mm before surgery and 5.7mm after surgery, while the mean right IFW ranged from 3.6mm to 3.9mm. The mean left SFW was 4.8mm before surgery and 5.2mm after surgery, while the mean left IFW ranged from 3.5mm to 3.9mm. Before surgery, the FAs were, on average, 77.1mm2 and 75.6mm2 on the right and left sides, respectively. At the 2-year follow-up, the mean FAs were 84.0mm2 and 80.2mm2 on the right and left sides, respectively. Contrary to prevalent belief, in patients who underwent single-level unilateral OLM, we observed that there may be an increase rather than a decrease in DH or foramen size at the 2-year follow-up. Our findings need to be confirmed by studies with larger sample sizes and longer follow-ups.

Effectiveness and safety of interspinous spacer versus decompressive surgery for lumbar spinal stenosis: A meta-analysis of randomized controlled trials.

A meta-analysis of randomized controlled trials. Our meta-analysis was conducted to investigate whether interspinous spacer (IS) results in better performance for patients with lumbar spinal stenosis (LSS) when compared with decompressive surgery (DS). DS and IS are common surgeries for the treatment of LSS. However, controversy remains as to whether the IS is superior to DS. We comprehensively searched PubMed, EMBASE, and Cochrane Central Register of Controlled Trials for prospective randomized controlled trials that compared IS versus DS for LSS. The retrieved results were last updated on July 30, 2023. Eight studies involving 852 individuals were included in the meta-analysis. The pooled data indicated that IS was superior to DS considering shorter operation time (P = .003), lower dural violation rate (P = .002), better Zurich Claudication Questionnaire Physical function score (P = .03), and smaller foraminal height decrease (P = .004), but inferior to DS considering the higher rate of reoperation (P < .0001). There was no significant difference between the 2 groups regarding hospital stay (P = .26), blood loss (P = .23), spinous process fracture (P = .09), disc height decrease (P = .87), VAS leg pain score (P = .43), VAS back pain score (P = .26), Oswestry Disability Index score (P = .08), and Zurich Claudication Questionnaire symptom severity (P = .50). In summary, we considered that IS had similar effects with DS in hospital stay, blood loss, spinous process fracture, disc height decrease, VAS score, Oswestry Disability Index score, and Zurich Claudication Questionnaire Symptom severity, and was better in some indices such as operation time, dural violation, Zurich Claudication Questionnaire Physical function, and foraminal height decrease than DS. However, due to the higher rate of reoperation in the IS group, we considered that both IS and DS were acceptable strategies for treating LSS. As a novel technique, further well-designed studies with longer-term follow-up are needed to evaluate the effectiveness and safety of IS.

Risk Factors of Subsidence after Anterior Cervical Discectomy and Fusion with Double Cylindrical Cages for Cervical Degenerative Diseases: Minimum Two-year Follow-up Results.

Cylindrical cages were known to cause subsidence after anterior cervical discectomy and fusion (ACDF); hence, they were gradually replaced by box-shaped cages. However, this phenomenon has been inconclusive due to limited information and short-term results. Therefore, this study aimed to clarify risk factors for subsidence after ACDF using titanium double cylindrical cages with mid-term follow-up periods. This retrospective study included 49 patients (76 segments) diagnosed with cervical radiculopathy or myelopathy caused by disc herniation, spondylosis, and ossification of the posterior longitudinal ligament. These patients underwent ACDF using these cages from January 2016 to March 2020 in a single institution. Patient demographics and neurological outcomes were also examined. Subsidence was defined as a ≥3-mm segmental disc height decrease at the final follow-up lateral X-ray compared to that on the next day postoperatively. Subsidence occurred in 26 of 76 segments (34.7%) within the follow-up periods of approximately three years. Multivariate analysis using a logistic regression model demonstrated that multilevel surgery was significantly associated with subsidence. The majority of patients achieved good clinical outcomes based on the Odom criteria. This study demonstrated that multilevel surgery was the only risk factor of subsidence post-ACDF with double cylindrical cages. Despite the relatively high subsidence rates, the clinical outcome was almost good at least during the mid-term period.

The mitophagy receptor BNIP3 is critical for the regulation of metabolic homeostasis and mitochondrial function in the nucleus pulposus cells of the intervertebral disc

ABSTRACT The contribution of mitochondria to the metabolic function of hypoxic NP cells has been overlooked. We have shown that NP cells contain networked mitochondria and that mitochondrial translocation of BNIP3 mediates hypoxia-induced mitophagy. However, whether BNIP3 also plays a role in governing mitochondrial function and metabolism in hypoxic NP cells is not known. BNIP3 knockdown altered mitochondrial morphology, and number, and increased mitophagy. Interestingly, BNIP3 deficiency in NP cells reduced glycolytic capacity reflected by lower production of lactate/H+ and lower ATP production rate. Widely targeted metabolic profiling and flux analysis using 1-2-13C-glucose showed that the BNIP3 loss resulted in redirection of glycolytic flux into pentose phosphate and hexosamine biosynthesis as well as pyruvate resulting in increased TCA flux. An overall reduction in one-carbon metabolism was noted suggesting reduced biosynthesis. U13C-glutamine flux analysis showed preservation of glutamine utilization to maintain TCA intermediates. The transcriptomic analysis of the BNIP3-deficient cells showed dysregulation of cellular functions including membrane and cytoskeletal integrity, ECM-growth factor signaling, and protein quality control with an overall increase in themes related to angiogenesis and innate immune response. Importantly, we observed strong thematic similarities with the transcriptome of a subset of human degenerative samples. Last, we noted increased autophagic flux, decreased disc height index and aberrant COL10A1/collagen X expression, signs of early disc degeneration in young adult bnip3 knockout mice. These results suggested that in addition to mitophagy regulation, BNIP3 plays a role in maintaining mitochondrial function and metabolism, and dysregulation of mitochondrial homeostasis could promote disc degeneration. Abbreviations: ECAR extracellular acidification rate; HIF hypoxia inducible factor; MFA metabolic flux analysis; NP nucleus pulposus; OCR oxygen consumption rate; ShBnip3 short-hairpin Bnip3

Эффективность рентгенологических методов диагностики нестабильности позвоночно-двигательного сегмента в шейном отделе

Introduction. Standard spine radiography is the basic method of radiodiagnosis, used for screening. X-ray imaging allows you to assess the anatomy of spinal motion segments in the cervical spine, determine the period of osteochondrosis and the tactics of further examination and treatment. Various types of dislocation of vertebrae are much more common than can be determined by spinal radiography in standard projections; as a result of dislocation, a pain syndrome occurs. Aim. To study the effectiveness of conventional methods for diagnosis of instability in the spinal motion segment (SMS) in the cervical spine. Materials and methods. We observed 50 patients (mean age 50.6 ± 2.19 years) who were admitted to the Clinic of the Irkutsk Scientific Center for Surgery and Traumatology (Neurosurgical Department) with a diagnosis Adult osteochondrosis of spine (ICD-10 code – M42.1). Conventional methods were used to diagnose SMS instability: plain radiography in anteroposterior and lateral projections, functional cervical spine radiography. Results. It was stated that the most common changes are characteristic of II and III periods of osteochondrosis: straightening of cervical lordosis – in 48 patients (96%), decrease in intervertebral disc height – in 46 patients (92%), anterior wedging of vertebral bodies – in 48 patients (96%), endplate sclerosis – in 37 patients (74%), presence of marginal osteophytes – in 45 patients (90%). In maximum flexion and extension, the CII–CVI vertebrae were involved in the formation of pathological mobility of the intervertebral segments, while the CI and CVII vertebrae remained stable. Instability in one cervical vertebra was revealed in 15 patients (30%). Most often, excessive mobility of 2 vertebrae was observed – in 22 people (44%), less often of 3 vertebrae – in 5 patients (10%). The dislocation of 4 vertebrae was quite rare – in 2 patients (4%). When analyzing the data of functional cervical spine radiography, we have found that the SMS instability in patients with intervertebral disc degeneration develops most often in the following segments: CII–CIII – 13 people (26%), СIII–СIV – 34 people (70%), CIV–CV – 29 people (58%), СV–СVI – 12 people (24%). Conclusion. The SMS instability still remains an urgent problem in neurology and neurosurgery. Plain radiography reveals only indirect signs of SMS instability. Diagnosis by functional spondylography made it possible to verify the SMS instability only in 36% of cases.

Oblique lumbar interbody fusion combined with stress end plate augmentation and anterolateral screw fixation for degenerative lumbar spinal stenosis with osteoporosis: a matched-pair case-controlled study

BACKGROUND CONTEXTOblique lumbar interbody fusion (OLIF) has been proven to be effective in treating degenerative lumbar spinal stenosis (DLSS). Whether OLIF is suitable for treating patients with DLSS with osteoporosis (OP) is still controversial. Bone cement augmentation is widely used to enhance the internal fixation strength of osteoporotic spines. However, the effectiveness of OLIF combined with bone cement stress end plate augmentation (SEA) and anterolateral screw fixation (AF) for DLSS with OP have not confirmed yet. PURPOSETo evaluate the clinical, radiological, and functional outcomes of OLIF-AF versus OLIF-AF-SEA in the treatment of DLSS with OP. STUDY DESIGNRetrospective case-control study. PATIENT SAMPLEA total of 60 patients with OP managed for DLSS at L4–L5. OUTCOME MEASURESVisual analog scale (VAS) score of the lower back and leg, Oswestry Disability Index (ODI), disk height (DH), lumbar lordosis (LL), segmental lordosis (SL), cage subsidence and fusion rate. METHODSThe study was performed as a retrospective matched-pair case‒controlled study. Patients with OP managed for DLSS at L4–L5 between October 2017 and June 2020 and completed at least 2 years of follow-up were included, which were 30 patients treated by OLIF-AF and 30 patients undergoing OLIF-AF-SEA. The demographics and radiographic data, fusion status and functional outcomes were therefore compared to evaluate the efficacy of the two approaches. RESULTSPain and disability improved similarly in both groups at the 24-month follow-up. However, the SEA group had lower pain and functional disability at 3 months postoperatively (p<.05). The mean postoperative disc height decrease (△DH) was significantly lower in the SEA group than in the control group (1.17±0.81 mm vs 2.89±2.03 mm; p<.001). There was no significant difference in lumbar lordosis (LL) or segmental lordosis (SL) between the groups preoperatively and 1 day postoperatively. However, a statistically significant difference was observed in SL and LL between the groups at 24 months postoperatively (p<.05). CS was observed in 4 cases (13.33%) in the SEA group and 17 cases (56.67%) in the control group (p<.001). A nonsignificant difference was observed in the fusion rate between the SEA and control groups (p=.347) at 24 months postoperatively. CONCLUSIONSThis study revealed that OLIF-AF-SEA was safe and effective in the treatment of DLSS with OP. Compared with OLIF-AF, OLIF-AF-SEA results in a minor postoperative disc height decrease, a lower rate of CS, better sagittal balance, and no adverse effect on interbody fusion.

Analysis of the clinical and radiological outcomes of percutaneous cervical nucleoplasty: A case-control study.

Percutaneous cervical nucleoplasty (PCN) is a simple, safe, and effective treatment for contained cervical herniated intervertebral disc (CHIVD). However, few studies have compared the actual benefits of PCN against conservative treatment (CT), either clinically or radiographically. The present study sought to analyze and to compare the outcomes of symptomatic contained CHIVD treated with PCN or CT. The present study was designed as a case-control comparative study. Patients who indicated for PCN after a failed CT for more than 6 months were recruited. After the exclusion of some patients who did not meet the selection criteria of the study, we finally enrolled 71 patients treated with PCN. In addition, another 21 patients who indicated for PCN but finally chose to receive CT continuously were also enrolled and categorized as the control group. All patients completed the 6-month follow-up. Pain levels and functional outcomes were evaluated pre- and post-operatively by assessing the visual analog scale (VAS), Oswestry Disability Index (ODI), and Neck Disability Index (NDI). Radiographic images of 72 of 104 intervened segments were collected to measure disc height and other cervical spinal alignments, such as range of motion, C2-7 Cobb's angle, and C2-7 sagittal vertical axis. Compared with the CT group, the PCN group showed significantly better outcomes on VAS, ODI, and NDI at the 1-month post-operative follow-up, which continued through at least the 6-month follow-up (P < 0.01 for VAS and P < 0.05 for ODI and NDI). The mean disc height significantly decreased, from 6.04 ± 0.85 mm to 5.76 ± 1.02 mm, 3 months after PCN treatment (P = 0.003). However, the degree of disc height decrease did not correlate with the changes of the substantial VAS improvement. To provide therapeutic benefits for symptomatic contained CHIVD patients after an invalid CT for 6 months, PCN seems to be a better option than CT. The reduced disc heights did not alter the clinical outcomes of PCN.

Magnetic resonance imaging in acute traumatic injuries of ligaments and soft tissues of cervical spine in children

Aim of the study: to study the role and possibilities of magnetic resonance imaging (MRI) in the diagnosis of injuries of ligaments and soft tissues of the cervical spine in emergency care. Materials and methods. MRI was performed in fifty two children with trauma of the cervical spine, in 1 of them with contrast enhancement. Boys predominated - 33 (63.5%), girls were 19 (36.5%). The age of the patients varied from 3 to 17 years, the mean age was 14 ± 1.4 years. The study was carried out on a Phillips Achieva dStream 3T scanner. The study protocol includes MR-myelography in sagittal and coronary projections, T2WI sagittal projection in PS STIR, T2WI SE, T1WI SE, DTI, axial projection of T2WI SE or T2*WI GRE. Results. Trauma of cervical spine was combined in 46% (n = 24) of all 52 cases, and in 54% (n = 28) it was isolated. During the clinical and neurological examination according to the ASIA impairment scale, there were 13 (25%) children with grade A, 3 (5.8%) with grade B, 9 (17.3%) with grade C, 4 (7.7%) with degree D and 23 (44.2%) with grade E. Spinal cord injuries in the form of hematomyelia were detected in 13 (25%) children, contusion and swelling of the spinal cord - in 15 children (29%). According to MRI results, 4 (7.7%) had a traumatic hernia with a decrease in disc height, 15 (28.8%) had secondary stenosis of the spinal canal at the time of the study, 28 (53.8%) had spinal cord compression and changes in the MR signal, 5 (9.6%) had epi- and subdural hematomas, 45 (86.5%) had vertebral fractures. Conclusion. MRI, as a method more sensitive than other imaging modalities in the diagnosis of soft tissue and spinal cord injuries, allows radiologist directly assessing the condition of spine soft tissues and, therefore, is critical in the evaluation of a patient with ligament injury and instability. Recognition of soft tissue injuries affects patient management and outcome.

Biomechanical Effect of Disc Height on the Components of the Lumbar Column at the Same Axial Load: A Finite-Element Study.

Intervertebral discs are fibrocartilage structures, which play a role in buffering the compression applied to the vertebral bodies evenly while permitting limited movements. According to several previous studies, degenerative changes in the intervertebral disc could be accelerated by factors, such as aging, the female sex, obesity, and smoking. As degenerative change progresses, the disc height could be reduced due to the dehydration of the nucleus pulposus. This study aimed to quantitatively analyze the pressure that each structure of the spine receives according to the change in the disc height and predict the physiological effect of disc height on the spine. We analyzed the biomechanical effect on spinal structures when the disc height was decreased using a finite-element method investigation of the lumbar spine. Using a 3D FE model, the degree and distribution of von-Mises stress according to the disc height change were measured by applying the load of four different motions to the lumbar spine. The height was changed by dividing the anterior and posterior parts of the disc, and analysis was performed in the following four motions: flexion, extension, lateral bending, and axial rotation. Except for a few circumstances, the stress applied to the structure generally increased as the disc height decreased. Such a phenomenon was more pronounced when the direction in which the force was concentrated coincided with the portion where the disc height decreased. This study demonstrated that the degree of stress applied to the spinal structure generally increases as the disc height decreases. The increase in stress was more prominent when the part where the disc height was decreased and the part where the moment was additionally applied coincided. Disc height reduction could accelerate degenerative changes in the spine. Therefore, eliminating the controllable risk factors that cause disc height reduction may be beneficial for spinal health.

Full Endoscopic Interlaminar Contralateral Lumbar Foraminotomy for Recurrent L5-S1 Foraminal-extraforaminal Stenosis: A Case Report with a Technical Note

After endoscopic lumbar foraminotomy, decreased disc height commonly causes foraminal restenosis and accompanying lateral recess stenosis. Interlaminar contralateral endoscopic lumbar foraminotomy can be used to treat multiple recurrent lesions instead of fusion surgery. Dorsal foraminal-extraforaminal decompression is challenging because of severe perineural adhesions. Therefore, neural decompression should be focused on the ventral foraminal expansion along the virgin dissection plane between the exiting nerve root and ventral foraminal pathologies. The prominent bony spur and herniated disc were removed using an endoscopic drill and forceps. As the foramen was enlarged, the endoscope was introduced deeper through the caudal-ventral foramen space to explore the extraforaminal and far-out lesions. Postoperatively, neurological deficits of L5 radiculopathy and radiating leg pain improved. The expanded foraminal-extraforaminal space was well maintained without progression of lateral wedging on the one-year follow-up images. We successfully treated recurrent foraminal-extraforaminal stenosis and combined lateral recess stenosis using the full endoscopic interlaminar contralateral approach at the L5-S1 level. This technique may be an alternative surgical method to treat the recurrent foraminal-extraforaminal stenosis in the collapse of the L5-S1 neuroforamen. However, this technique should be considered in highly selected patients unsuitable for fusion operations.

Factors associated with disc degeneration based on Pfirrmann criteria after condoliase treatment for lumbar disc herniation

BackgroundLumbar disc herniation (LDH) is a common cause of low back pain and is associated with degeneration of the nucleus pulposus causing nerve root compression. Chemonucleolysis of the nucleus pulposus with condoliase is a low-invasive treatment for LDH. The purpose of this study was to investigate changes in Pfirrmann criteria, which are used to evaluate disc degeneration, after injection of condoliase into a herniated intervertebral disc, and to identify factors associated with disc degeneration at 3 months post-injection. MethodsMedical records and radiographic findings were reviewed retrospectively for 127 patients with LDH (88 male, 39 female, mean age: 46.6 ± 17.1 years, mean follow-up: 9.8 ± 7.8 months) who underwent chemonucleolysis with intradiscal condoliase injection at our center since September 2018. Condoliase (1.25 U/mL; 1 mL volume) was injected toward the middle of the affected intervertebral nucleus pulposus using a 21-gauge disc-puncture needle. ResultsCases in which the Pfirrmann grade did and did not progress in the 3 months after the injection were included in groups P (progression, n = 49) and NP (non-progression, n = 78), respectively. Logistic regression analysis of progression of Pfirrmann grade post-injection showed significant associations with age <40 years (p = 0.013, odds ratio (OR): 3.69, 95% confidence interval (CI): 1.32–10.31), Pfirrmann Grade II or III at baseline (p = 0.021, OR: 3.51, 95% CI: 1.24–9.64), and a high-intensity MRI signal in the herniation (p = 0.047, OR: 2.97, 95% CI: 1.03–8.87). Patients in group P had significantly higher rates of disc height decrease ≥20%, reduced herniated disc size, and improved VAS for pain, but both groups had significant decreases in pain. No cases had anaphylactic shock or neurologic sequelae. ConclusionsThese results show the safety and efficacy of chemonucleolysis with condoliase for treatment of painful LDH. Progression of Pfirrmann criteria on MRI at 3 months after injection was significantly associated with an improved clinical outcome.

Comparison of robot-assisted versus fluoroscopy-assisted minimally invasive transforaminal lumbar interbody fusion for degenerative lumbar spinal diseases: 2-year follow-up.

This study was performed to prospectively compare the clinical and radiographic outcomes between robot-assisted minimally invasive transforaminal lumbar interbody fusion (RA MIS-TLIF) and fluoroscopy-assisted minimally invasive transforaminal lumbar interbody fusion (FA MIS-TLIF) in patients with degenerative lumbar spinal diseases. One hundred and twenty-three patients with lumbar degenerative diseases (lumbar spinal stenosis with instability and spondylolisthesis [degenerative spondylolisthesis or isthmic spondylolisthesis]) who underwent MIS-TLIF in our hospital were included in this study. Sixty-one patients underwent RA MIS-TLIF (Group A) and 62 patients underwent FA MIS-TLIF (Group B). Group A was further divided into Subgroup AI (46 single-level procedures) and Subgroup AII (15 double-level procedures). Group B was further divided into Subgroup BI (45 single-level procedures) and Subgroup BII (17 double-level procedures). The clinical outcome parameters were the visual analog scale (VAS) score, Oswestry Disability Index (ODI) score, operative time, number of intraoperative fluoroscopies, blood loss, postoperative hospital stay, and postoperative complications. The radiographic change measures were the accuracy of screw placement, facet joint violation (FJV), fusion status, and change in disc height at the proximal adjacent segment at the 2-year follow-up. There were no significant differences in the VAS and ODI scores, blood loss, or postoperative hospital stay between Groups A and B (p > 0.05). The operative time was longer in Group A than B (p = 0.018). The operative time was longer in Subgroup AI than BI (p = 0.001). However, there was no significant difference between Subgroups AII and BII (p > 0.05). There was no significant difference in the number of intraoperative fluoroscopies for patients between Groups A and B (p > 0.05). Although the number of intraoperative fluoroscopies for patients was significantly higher in Subgroup AI than BI (p = 0.019), there was no significant difference between Subgroups AII and BII (p > 0.05). The number of intraoperative fluoroscopies for the surgeon was significantly lower in Group A than B (p < 0.001). For surgeons, the difference in the average number of intraoperative fluoroscopies between Subgroups AI and AII was 2.98, but that between Subgroups BI and BII was 10.73. In Group A, three guide pins exhibited drift and one patient developed a lateral wall violation by a pedicle screw. One pedicle screw perforated the anterior wall of the vertebral body and another caused an inner wall violation in Group B. The rate of a perfect screw position (grade A) was higher in Group A than B (p < 0.001). However, there was no significant difference in the proportion of clinically acceptable screws (grades A and B) between the two groups. The mean FJV grade was significantly higher in Group B than A (p < 0.001). During at 2-year postoperative follow-up, there was no significant difference in the fusion status between the two groups (p > 0.05); however, the decrease in disc height at the proximal adjacent segment was significantly less in Group A than B (p < 0.001). Robot-assisted percutaneous pedicle screw placement is a safer and more accurate alternative to conventional freehand fluoroscopy-assisted percutaneous pedicle screw insertion in MIS-TLIF.

Degenerative Spondylolisthesis Factors at Level L4–5: MR Imaging Findings

Introduction: Over time, the body, including the spine, undergoes anatomical and morphological changes. Magnetic resonance (MR) imaging is a good modality to analyse degenerative processes by evaluating joint deformity and fat accumulation in bone and muscle. We studied MR images from 22 patients diagnosed with spondylolisthesis at level L4-5 to characterise the factors that cause spondylolisthesis, including disc degeneration, facet joint osteoarthritis, fatty infiltration of the multifidus muscle and thickening of the ligamentum flavum. Materials and Methods: Twenty-two patients with degenerative spondylolisthesis diagnosed by MR imaging were enrolled in this study to characterise the following factors in the degenerative spine at level L4-5: intervertebral disc, facet joint, multifidus muscle and ligamentum flavum. Results: None of the evaluated factors were normal at level L4-5; all had degenerated to various degrees. Twelve discs (54.5%) showed a significant decrease in disc height with a hypointense signal, indicating grade IV. Fifteen cases (68.1%) showed narrowing and irregularity of the facet joint with marked osteophytes, suggesting severe joint osteoarthritis. In 11 cases (50%), fat had already infiltrated the multifidus muscles such that there was an equal amount of fat and muscle tissue, indicating grade III on the Goutallier classification. Thickening of ligamentum flavum was also observed, with maximal thickening of 6.7 mm (right) and 7.1 mm (left). Conclusion: Our study confirms that degeneration of the intervertebral disc, facet joint osteoarthritis, multifidus muscle fatty infiltration and thickening of ligamentum flava are present in patients with spondylolisthesis at level L4-5.

Comparison and optimization of sheep in vivo intervertebral disc injury model.

BackgroundThe current standard of care for intervertebral disc (IVD) herniation, surgical discectomy, does not repair annulus fibrosus (AF) defects, which is partly due to the lack of effective methods to do so and is why new repair strategies are widely investigated and tested preclinically. There is a need to develop a standardized IVD injury model in large animals to enable comparison and interpretation across preclinical study results. The purpose of this study was to compare in vivo IVD injury models in sheep to determine which annulus fibrosus (AF) defect type combined with partial nucleus pulposus (NP) removal would better mimic degenerative human spinal pathologies.MethodsSix skeletally mature sheep were randomly assigned to one of the two observation periods (1 and 3 months) and underwent creation of 3 different AF defect types (slit, cruciate, and box‐cut AF defects) in conjunction with 0.1 g NP removal in three lumbar levels using a lateral retroperitoneal surgical approach. The spine was monitored by clinical CT scans pre‐ and postoperatively, at 2 weeks and euthanasia, and by magnetic resonance imaging (MRI) and histology after euthanasia to determine the severity of degeneration (disc height loss, Pfirrmann grading, semiquantitative histopathology grading).ResultsAll AF defects led to significant degenerative changes detectable on CT and MR images, produced bulging of disc tissue without disc herniation and led to degenerative and inflammatory histopathological changes. However, AF defects were not equal in terms of disc height loss at 3 months postoperatively; the cruciate and box‐cut AF defects showed significantly decreased disc height compared to their preoperative height, with the box‐cut defect creating the greatest disc height loss, while the slit AF defect showed restoration of normal preoperative disc height.ConclusionsThe tested IVD injury models do not all generate comparable disc degeneration but can be considered suitable IVD injury models to investigate new treatments. Results of the current study clearly indicate that slit AF defect should be avoided if disc height is used as one of the main outcomes; additional confirmatory studies may be warranted to generalize this finding.

Predictors of long-term clinical outcomes in adult patients after lumbar total disc replacement: development and validation of a prediction model.

Long-term outcomes of single-level lumbar arthroplasty are understood to be very good, with the most recent Investigational Device Exemption (IDE) trial showing a < 5% reoperation rate at the close of the 7-year study. This post hoc analysis was conducted to determine whether specific patients from the activL IDE data set had better outcomes than the mean good outcome of the IDE trial, as well as to identify contributing factors that could be optimized in real-world use. Univariable and multivariable logistic regression models were developed using the randomized patient set (n = 283) from the activL trial and used to identify predictive factors and to derive risk equations. The models were internally validated using the randomized patient set and externally validated using the nonrandomized patient set (n = 52) from the activL trial. Predictive power was assessed using area under the receiver operating characteristic curve analysis. Two factors were significantly associated with achievement of better than the mean outcomes at 7 years. Randomization to receive the activL device was positively associated with better than the mean visual analog scale (VAS)-back pain and Oswestry Disability Index (ODI) scores, whereas preoperative narcotics use was negatively associated with better than the mean ODI score. Preoperative narcotics use was also negatively associated with return to unrestricted full-time work. Other preoperative factors associated with positive outcomes included unrestricted full-time work, working manual labor after index back injury, and decreasing disc height. Older age, greater VAS-leg pain score, greater ODI score, female sex, and working manual labor before back injury were identified as preoperative factors associated with negative outcomes. Preoperative BMI, VAS-back pain score, back pain duration ≥ 1 year, SF-36 physical component summary score, and recreational activity had no effect on outcomes. Lumbar total disc replacement for symptomatic single-level lumbar degenerative disc disease is a well-established option for improving long-term patient outcomes. Discontinuing narcotics use may further improve patient outcomes, as this analysis identified associations between no preoperative narcotics use and better ODI score relative to the mean score of the activL trial at 7 years and increased likelihood of return to work within 7 years. Other preoperative factors that may further improve outcomes included unrestricted full-time work, working manual labor despite back injury, sedentary work status before back injury, and randomization to receive the activL device. Tailoring patient care before total disc replacement may further improve patient outcomes.

Risk factors of unsatisfactory outcomes after percutaneous laser decompression of lumbar intervertebral discs

To study the risk factors of unsatisfactory clinical results after percutaneous laser decompression of the lumbar intervertebral disc (PLDD). A retrospective observational single-center study included medical records of patients who underwent lumbar PLDD for degenerative spine disease. We analyzed clinical and instrumental parameters potentially affecting the results of lumbar PLDD. Clinical study included 82 patients who underwent PLDD for lumbar intervertebral disc degenerative disease. Mean postoperative follow-up period was 30.8±13.3 months. In 22 (26%) patients, unsatisfactory clinical outcomes were observed. According to binary logistic regression model, comorbidities (p=0.03), duration of disease over 12 months (p=0.03), low preoperative quality of life according to ODI score (more than 50%) (p=0.04), high body mass index (over 25 kg/m2) (p=0.02), severe intervertebral disc (p=0.04) and facet joint degeneration (p=0.01) and intervertebral disc height decrease more than 50% (p=0.01) were significantly associated with unsatisfactory clinical outcomes after lumbar PLDD for degenerative spine disease. Identification of these risk factors of unsatisfactory clinical outcomes is important stage of preoperative preparation in patients scheduled for lumbar PLDD.