Mean Disc Height Research Articles

Clinical Outcomes of the Transforaminal Lumbar Interbody Fusion Technique Among Patients With Low Back Pain Showing Type 1 Modic Changes on MRI.

Introduction The unilateral transforaminal lumbar interbody fusion (TLIF) signifies a different surgical method, circumventing both the anterior method and the method via the spinal canal. Due to the shortage of literature available for clinical outcomes and consequences post-TLIF, we undertook the current study to assess the TLIF technique's clinical outcomes among patients with low back pain showing type 1 Modic changes on MRI. Material and methods A cross-sectional study was conducted between January 2019 and March 2021. All patients included in the study had Modic type 1 change and disabling lowback pain as the main complaint and/or leg pain. Data were collected on age, body mass index (BMI), gender, and other risk factors like diabetes mellitus, steroid use, and smoking. Pain intensity was evaluated using a visual analog scale (VAS) before and after surgery. A radiographic evaluation was also performed. Preand post-operative pain scores and differences in disc height were assessed using the Wilcoxon rank sum test. A p-value of less than 0.05 was considered significant. Results The mean length of stay in the hospital was 4.3±1.61. The mean pre-operative lower back pain score was 8.78±0.79. The mean post-operative score was substantially lowered to 0.83±0.7. There was a significant difference between pre- and post-operative lumbar pain (p-value < 0.001). There was a significant increase in mean disc height from pre-operative (7.14 mm) to post-operative (11.02 mm) and also at one year (10.21 mm) with a p-value of <0.001. Of the patients,82.14% did not have any complications, and 3.57% each had either delayed wound healing without any infection or transient post-operative radiculopathy that improved in six weeks. Conclusion TLIF procedure can be considered safeto provide anterior and posterior column support by adopting a unilateral posterior approach. The outcomes were favorable in terms of no prolonged length of stay, less blood loss, no mortality, reduction in the severity of pain, and improvement in disc height. However, the appropriate selection of patients for this technique is pivotal for the success of the procedure.

Risk Factors for Cervical Disc Arthroplasty Subsidence with Bryan Disc-A Retrospective Observational Analysis.

Background: Cervical disc arthroplasty (CDA) is currently used instead of fusion to preserve cervical spine motion. Cervical implant subsidence is a potential complication after CDA. Methods: Radiological measurements were recorded via patient anteroposterior and lateral radiographs in the neutral position. Subsidence was defined as a decrease of 3 mm or more in functional spinal unit height (FSUH) from which was measured on a post-operative (OP) radiograph. Results: This study included 104 patients who underwent 153 CDA levels with the Bryan Disc. Approximately one-quarter of the implants (22.9%) showed subsidence. Binary logistic regression analysis indicated that pre-OP mean disc height (DH) was identified as an independent risk factor for subsidence in multivariate analysis (0.151, 95% Confidence Interval 0-0.073, p = 0.018). Receiver operating characteristic curve analysis (area under the curve = 0.852, sensitivity 84.7%, specificity 77.1%) revealed a cut-off value of 4.48 mm for pre-OP Mean-DH in the risk for implant subsidence. Conclusions: In this study, the subsidence rate significantly increased when the implants were oversized beyond a pre-OP Mean-DH of approximately >4 mm. Moreover, the implant subsidence incidence was higher than that reported in previous studies. This is possibly due to endplate over-preparation or disc space over-distraction during placement at the same height as the Bryan Disc (8.5 mm).

SPINAL ANATOMY AND BEYOND: INVESTIGATING DEGENERATIVE DISC DISEASE

Degenerative disc disease is a common manifestation in routine spine imaging; this finding is partly attributable to physiological aging and partly to a pathological condition, and sometimes, this distinction is simply not clear. The study's main objective is to find the spinal anatomy and investigate degenerative disc disease in spinal patients. This mixed-methods study was conducted in a public hospital in Karachi, Pakistan from March 2023 to September 2023. Fifty patients diagnosed with DDD are enrolled, with comprehensive clinical assessments conducted to evaluate symptomatology, functional impairment, and radiological findings. Additionally, advanced imaging modalities, including MRI and CT scans, elucidate structural changes within the spinal column. Preliminary analysis reveals a mean disc height loss of 3.2 mm (±0.8) across the study cohort, with significant variability observed among individual patients. Annular tears are prevalent in 70% of cases, predominantly localized to the lumbar spine. Furthermore, facet joint degeneration is evident in 85% of patients, with a mean grade of 2.4 (±0.6) on the Pfirrmann scale. Correlation analysis demonstrates a moderate positive correlation (r = 0.56, p &lt; 0.001) between disc height loss and severity of clinical symptoms. It is concluded that this study provides the complex pathology of degenerative disc disease (DDD) and its impact on spinal anatomy. Through a comprehensive investigation involving clinical assessments and advanced imaging techniques, we have elucidated the spectrum of degenerative changes within the intervertebral discs and facet joints.

Lateral fenestration of lumbar intervertebral discs in rabbits: development and characterisation of an in vivo preclinical model with multi-modal endpoint analysis

PurposeTo evaluate the biological and biomechanical effects of fenestration/microdiscectomy in an in vivo rabbit model, and in doing so, create a preclinical animal model of IVDD.MethodsLateral lumbar IVD fenestration was performed in vivo as single- (L3/4; n = 12) and multi-level (L2/3, L3/4, L4/5; n = 12) fenestration in skeletally mature 6-month-old New Zealand White rabbits. Radiographic, micro-CT, micro-MRI, non-destructive robotic range of motion, and histological evaluations were performed 6- and 12-weeks postoperatively. Independent t tests, one-way and two-way ANOVA and Kruskal–Wallis tests were used for parametric and nonparametric data, respectively. Statistical significance was set at P < 0.05.ResultsAll rabbits recovered uneventfully from surgery and ambulated normally. Radiographs and micro-CT demonstrated marked reactive proliferative osseous changes and endplate sclerosis at fenestrated IVDs. Range of motion at the fenestrated disc space was significantly reduced compared to intact controls at 6- and 12-weeks postoperatively (P < 0.05). Mean disc height index percentage for fenestrated IVDs was significantly lower than adjacent, non-operated IVDs for both single and multi-level groups, at 6 and 12 weeks (P < 0.001). Pfirrmann MRI IVDD and histological grading scores were significantly higher for fenestrated IVDs compared to non-operated adjacent and age-matched control IVDs for single and multi-level groups at 6 and 12 weeks (P < 0.001).ConclusionsFenestration, akin to microdiscectomy, demonstrated significant biological, and biomechanical effects in this in vivo rabbit model and warrants consideration by veterinary and human spine surgeons. This described model may be suitable for preclinical in vivo evaluation of therapeutic strategies for IVDD in veterinary and human patients.

How to Choose Surgical Corridor in Left Oblique Approach Lumbar Interbody Fusion at the L5-S1 Segment: A Prospective Cohort Study

PurposeThere are two surgical corridors to L5-S1 lumbar interbody fusion via the left oblique approach: anterior to psoas-oblique lateral interbody fusion (ATP-OLIF) and oblique-anterior lumbar interbody fusion (O-ALIF). The aim of this study was to evaluate criteria to guide the selection of surgical corridors for L5-S1 lumbar interbody fusion via the left oblique approach. MethodsAccording to the structure of L5-S1 segment left common iliac vein (LCIV) in axial magnetic resonance image, the LCIV was divided into six types. O-ALIF was performed for type I and type II. ATP-OLIF was performed for type A and type B. For sexually active men, ATP-OLIF was chosen. Between April 2020 and April 2022, 22 patients were assigned to ATP-OLIF or O-ALIF based on the type of LCIV. Clinical outcomes and radiographic outcomes were assessed. ResultsThere were 11 cases in O-ALIF group (type I, n = 10; type II, n = 1) and 11 cases in ATP-OLIF group (type A, n = 8; type B, n = 3). No differences were observed in clinical outcomes (ODI, VAS, and complication rate), radiographic outcomes (mean disc height and segmental lordosis angle), length of hospital stay, operation time, and blood loss. No vascular injury occurred in either group. ConclusionsThis may be an appropriate criterion to guide the selection of surgical corridor for L5-S1 lumbar interbody fusion through the left oblique approach. O-ALIF was performed for type I and type II. ATP-OLIF was performed for type A and type B. For sexually active men, ATP-OLIF was chosen. According to this standard, the operation can be performed safely and with good clinical results.

Oblique lateral internal fusion combined with percutaneous pedicle screw fixation in severe lumbar spinal stenosis: clinical and radiographic outcome

BackgroundOblique lumbar interbody fusion (OLIF) has been a popular technique for treating lumbar degenerative diseases. Previous studies have shown its efficiency in lumbar spinal stenosis; yet, only a few studies have investigated its application to severe lumbar spinal stenosis. Herein, we investigated the clinical and radiographic outcome of OLIF with percutaneous pedicle screws in the treatment of severe lumbar spinal stenosis.MethodsA total of 15 patients who underwent OLIF with percutaneous pedicle screws were retrospectively analysed. All patients were diagnosed with severe lumbar stenosis (Schizas grade C or D) through preoperative magnetic resonance image (MRI) and received OLIF combined with percutaneous pedicle screw surgery. Clinical outcomes, including visual analogue scale (VAS)-back and VAS-leg scores, and Oswestry Disability Index (ODI), as well as mean disc height (DH), mean foraminal height (FH), segmental lumbar lordosis (SLL) and cross-sectional area (CSA) of the spinal canal, were analysed before and after surgery and at the last follow-up. Intraoperative data, complications and fusion rate were also investigated.ResultsOLIF combined with percutaneous pedicle screws was performed on 18 segments in 15 patients. Mean follow-up was 23.1 ± 4.6 months (range 15–29 months). VAS-back, VAS-leg, and ODI scores were significantly improved at the last follow-up. DH increased from 8.86 ± 3.06 mm before surgery to 13.31 ± 2.14 mm after; at the last follow-up, DH was 11.69 ± 1.87 mm. FH increased from 17.85 ± 2.26 mm before surgery to 22.09 ± 1.36 mm after; at the last follow-up, FH was 20.41 ± 0.99 mm. CSA of the spinal canal increased from 30.83 ± 21.15 mm2 before surgery to 74.99 ± 33.65 mm2 after the operation and 81.22 ± 35.53 mm2 at the last follow-up. The segmental LL before surgery, after surgery and at last follow-up was 20.27 ± 6.25 degrees, 20.83 ± 6.52 degrees and 19.75 ± 5.87 degrees, respectively. All patients have gained fusion at the last follow-up.ConclusionOLIF with percutaneous pedicle screws could achieve satisfactory clinical and radiographic effects through indirect compression by increasing DH, FH and CSA of the spinal canal in severe lumbar stenosis patients.

Clinical and Radiographic Outcomes for Patients with Cervical Adjacent Segment Disease Treated with Anterior Cervical Discectomy and Fusion with Integrated Interbody Spacers

Anterior cervical discectomy and fusion (ACDF) is among the most common spine procedures. Adjacent segment disease (ASD), characterized by degenerative disease at an adjacent spinal level to a prior fusion, is a well-recognized and significant sequela following ACDF. Adjacent segment ACDF may be considered after the failure of non-surgical options for patients with symptomatic ASD. This study aimed to assess the incidence of dysphagia and other complications as well as radiographic outcomes in adult patients who have undergone ACDF with an integrated interbody spacer device for symptomatic ASD. This was a retrospective review of patients who underwent ACDF for symptomatic ASD with commercially available integrated interbody spacers by three spine surgeons at an academic institution from March 2018 to April 2022. Demographic, radiographic, and postoperative data were collected, including dysphagia, device-related complications, and the need for revision surgery. There were 48 patients (26 male, 22 female) who met inclusion criteria (mean age 59.7 years, mean body mass index 19.5 kg/m2) who underwent ACDF for symptomatic ASD (1one-level, n= 44; 2-level, n= 4). Overall, 12 patients (25%) experienced dysphagia postoperatively before the first follow-up appointment. Nine of 44 (20.4%) of 1-level ACDF patients experienced dysphagia, and 3 of 4 (75%) of 2-level ACDF patients experienced dysphagia. Three patients had severe dysphagia which prompted an otolaryngology referral. Two of those patients remained symptomatic at 6 weeks postoperatively. Of 43 patients with prior plate cage systems, none required hardware removal at the time of surgery. Preoperative global and segmental lordosis were 9.07° ± 8.36° (P= 0.22) and 3.58° ± 4.57° (P= 0.14), respectively. At 6 weeks postoperatively, global and segmental lordosis were 11.44° ± 9.06° (P= 0.54) and 5.11° ± 4.44° (P= 0.44), respectively. This constitutes a change of+2.37° and+1.53° in global and segmental lordosis, respectively. The mean anterior disc height change between preoperative and immediate postoperative time points was 6.3 ± 3.1 mm. Between the immediate postoperative and 6-week postoperative time points, the mean anterior disc height change was -1.5 ± 2.7 mm. Between the immediate postoperative and 3-month postoperative time points, the mean anterior disc height change was -3.7 ± 5.0 mm. The posterior disc height changes at the same time points were 2.5 ± 1.7 mm, -0.4 ± 1.8. and -0.5 ± 1.4 mm, respectively. This fusion rate was 50% and 70% at 6 months and 1 year post-surgery, respectively. ACDF with integrated spacer is a viable alternative to traditional plate-cage systems for symptomatic ASD. An advantage over traditional plate-cage systems is that the removal of prior instrumentation is not needed in order to place implants. Based on a review of the literature, these standalone systems allowed for a shorter operative time and had less incidence of dysphagia than plate-cage systems for ASD after ACDF. The different standalone and plate-cage systems used in treating ASD after ACDF surgeries should be compared in prospective studies.

Comparing optic nerve head parameters in two Spanish dog breeds using digital planimetry

The optic discs of dogs exhibit considerable size, shape, and colour variations, depending on the degree of myelination. This variability makes the interpretation of lesions difficult, owing to the lack of reference patterns. This study aimed to compare optic nerve head (ONH) parameters determined by digital planimetry (DP) in two pure-bred dogs, Spanish Greyhound (SG) and Spanish Water Dog (SWD). The vertical and horizontal diameters, area, circularity, and the proportion of the ONH at the tapetal or non-tapetal zone (top height and bottom height) were calculated using image treatment software and compared between breeds.Significant between-breed differences were detected for all parameters, with SWD exhibiting greater height, width, area, top height, and lower circularity of the ONH than SG. Linear regression revealed that age significantly influenced mean disc height (R2 = 0.310; p = 0.0001), mean disc width (R2 = 0.280; p = 0.0001), mean disc area (R2 = 0.281; p = 0.0001), and circularity (R2 = 0.243; p = 0.0001). The multiple regression model significantly predicted mean disc height, width, and area [(S) (R2 = 0.715; p = 0.001), (R2 = 0.742; p = 0.001), and (S) (R2 = 0.736; p = 0.001), respectively], based on age and breed. Excellent concordance was observed between the measurements of experienced and novice researchers, and there were no differences between the parameters measured by the researcher and those obtained by the software. Planimetric ONH measurements can be easily performed by novice operators using a portable fundus camera and digital computer software. These results may be of considerable clinical value, but further studies are required because of the great variability of the ONH in dogs.

Is Intervertebral Disc Degeneration a Compensatory Mechanism in Adult Tethered Cord Syndrome?

The purpose of the present study was to evaluate the influence of high nerve tension on lumbar disc degeneration and sagittal morphologies. A total of 50 young and middle-aged patients (mean age 32.1±7.4years, 22 men and 28 women) who suffered from tethered cord syndrome (TCS) were retrospectively assessed by two observers. Demographic and radiological data were recorded, including lumbar disc degeneration, disc height index and lumbar spine angle, and were compared with 50 patients (mean age 29.7±5.4 years, 22 men and 28 women) without spinal cord abnormalities. Statistical associations were assessed by student's t-test and chi-square test. Our results showed patients with TCS had a significantly higher rate of lumbar disc degeneration in L1/2, L2/3, L4/5 and L5/S1 than in those without TCS (P < 0.05). Moreover, the rates of multilevel disc degeneration and severe disc degeneration in TCS group were significantly higher than those in control group (P < 0.01). The mean disc height index of L3/4 and L4/5 in TCS group was significantly lower than that in control group (P < 0.05). The mean lumbosacral angle of TCS patients was significantly higher than that of patients without TCS (38.4±3.5°vs. 33.7±5.9°, P < 0.01). We found a certain correlation between TCS and lumbar disc degeneration and lumbosacral angle enlargement, suggesting that the spine reduces the high tension of the spinal cord through disc degeneration. Therefore, it is speculated that there is a "compromised regulation" mechanism in the body under the condition of neurological abnormalities.

The predictive value of Hounsfield units for titanium mesh cage subsidence after anterior cervical corpectomy and fusion.

To investigate whether bone mineral density (BMD) measured in Hounsfield units (HUs) correlates with titanium mesh cage (TMC) subsidence after anterior cervical corpectomy and fusion (ACCF). A total of 64 patients who underwent one or two levels of ACCF with TMC with a mean follow-up of 19.34 ± 7.86 months were analysed. HU values were measured three times in 3 different planes in the upper and lower vertebrae according to published methods. Subsidence was defined as segmental height loss of more than 3 mm. Pearson correlation analysis was performed. Receiver operating characteristic (ROC) curve analysis was used to obtain optimal thresholds. A multivariate logistic regression analysis was also conducted. Twenty-two patients (34.38%) had evidence of TMC subsidence on follow-up x-ray. The mean HU values in the subsidence group (317.34 ± 32.32, n = 22) were significantly lower than those in the nonsubsidence group (363.07 ± 25.23 n = 42, p < 0.001, t test). At last follow-up, mean disc height loss was 4.80 ± 1.16 mm in the subsidence group and 1.85 ± 1.14 mm in the nonsubsidence group (p < 0.001). There was a negative correlation between HU values and disc height loss (Pearson's coefficient -0.494, p < 0.001). HU values decreased gradually from the C3 vertebra to the C7 vertebra, and the HU values of the C5, C6, and C7 vertebrae in the nonsubsidence group were significantly higher than those in the subsidence group (p < 0.05). Furthermore, there were significant differences between the groups in the segmental angle at the last follow-up and the mean changes in segmental angle (p < 0.05). The area under the ROC curve was 0.859, and the most appropriate threshold of the HU value was 330.5 (sensitivity 100%, specificity 72.7%). The multivariate logistic regression analysis showed that older age (p = 0.033, OR = 0.879), lower LIV HU value (p < 0.001, OR = 1.053) and a greater segmental angle change (p = 0.002, OR 6.442) were significantly associated with a higher incidence of TMC subsidence after ACCF. There are strong correlations between a lower HU value and TMC subsidence after ACCF. More accurate assessment of bone quality may be obtained if HU measurement can be used as a routine preoperative screening method together with DXA. For patients with HU values <330.5, a more comprehensive and cautious preoperative plan should be implemented to reduce TMC subsidence.

Clinical and radiographic outcomes of stand-alone oblique lateral interbody fusion in the treatment of adult degenerative scoliosis: a retrospective observational study

BackgroundOpen fusion and posterior instrumentation has traditionally been the treatment for adult degenerative scoliosis (ADS). However, minimally invasive treatment such as oblique lateral interbody fusion (OLIF) technique was developed as a new therapeutic method for the treatment of ADS. In addition, it is associated with decreased blood loss and shorter operative time without posterior instrument. The purpose of this study was to evaluate the efficiency of stand-alone OLIF for the treatment of ADS in terms of clinical and radiological results.MethodsA total of 30 patients diagnosed with ADS who underwent stand-alone OLIF in our hospital from July 2017 to September 2018 were enrolled in the study. Scores from the Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI) obtained preoperatively and at the final follow-up were compared. Radiography and computed tomography were performed preoperatively and at the final follow-up. The coronal cobb angle, lumbar lordosis, disc height, sacral slope, pelvic incidence and Pelvic tilt were recorded at each time point.ResultsThe study cohort comprised 30 patients with a mean age of 64.5 ± 10.8 years and mean follow-up of 19.3 ± 4.2 months. The mean operative time was 96.8 ± 29.4 minutes and the mean estimated blood loss volume was 48.7 ± 9.4 ml. The mean coronal Cobb angle was corrected from 15.0° ± 3.7° preoperatively to 7.2° ± 3.1° postoperatively and 7.2° ± 3.3° at final follow-up (P < 0.0001). Lumbar lordosis significantly improved from 32.2° ± 11.3° preoperatively to 40.3° ± 11.8° postoperatively and 40.7° ± 11.0° at final follow-up (P < 0.01). The respective mean sacral slope and pelvic tilt improved from 26.1° ± 8.1° and 25.1° ± 6.9° preoperatively to 34.3° ± 7.4° and 19.2° ± 5.7° at final follow-up (P < 0.001). The mean disc height (defined as the mean of the anterior and posterior intervertebral disc heights) increased from 0.7 ± 0.3 cm preoperatively to 1.1 ± 0.2 cm at final follow-up (P < 0.0001). The interbody fusion rate on CT was 93.3%. The mean VAS pain score improved from 5.3 ± 0.6 before surgery to 2.3 ± 0.6 at final follow-up (P < 0.001). The mean ODI improved from 29.9% ± 6.8% preoperatively to 12.8% ± 2.4% at final follow-up (P < 0.001).ConclusionsStand-alone OLIF is an effective and safe option for treating ADS in carefully selected patients.Trial registrationThe study was registered in the Chinese Clinical Trial Registry (ChiCTR2100052419).

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.

Condoliase therapy for lumbar disc herniation -2 year clinical outcome-

BackgroundCondoliase-induced chemonucleolysis is a less invasive treatment for lumbar disc herniation (LDH); however, its long-term clinical outcomes remain unclear. We investigated 2-year clinical outcomes and assess radiographs after chemonucleolysis with condoliase. MethodsWe enrolled patients with LDH who received condoliase therapy, with a minimum follow-up period of two years. Sixty-seven patients (44 men, 23 women; mean age, 46.7 ± 18.0 years) were analyzed. Time-course changes in disc height, disc degeneration, and herniation size were assessed. For clinical outcomes assessment, visual analog scale (VAS) scores for leg and back pain and the Oswestry disability index (ODI) were obtained at baseline and the 3-month, 1-year, and 2-year follow-ups. We obtained a questionnaire from these patients at two years to assess satisfaction and recommendation. Condoliase therapy was considered to be effective in patients whose VAS score for leg pain improved by ≥ 50% at 2 years from baseline and who did not require surgery. ResultsCondoliase therapy was effective in 51 patients (76.1%). Eight patients (11.9%) required surgery due to ineffectiveness of the therapy. Condoliase therapy was ineffective in five out of six patients with a history of discectomy. The ODI and VAS scores for leg and back pain significantly improved from three months to two years. Of the patients, 80% satisfied with their outcomes, and 85% recommended this therapy. Progression of disc degeneration was observed in 57.1% of patients at three months; however, 30% recovered to baseline at two years. The mean disc height decreased at three months, but recovered slightly at one year and remained stable until two years. No recurrent disc herniation was observed. ConclusionsChemonucleolysis with condoliase was effective in 78% of patients with LDH for 2 years. Chemonucleolysis-induced disc degeneration was slightly recovered and maintained for two years post-injection. This treatment resulted in high patient satisfaction and recommendations.

Excessive Fluid in the Lumbar Facet Joint as a Predictor of Radiological Outcomes After Lateral Lumbar Interbody Fusion.

Background Preoperative segmental instability maybe a predictor of postoperative outcomes when treated with lateral lumbar interbody fusion (LLIF). An abnormal collection of fluid within the facet joint has been described as a sign of segmental instability. The potential relationship between this radiological sign and its prognostic relevance for indirect decompression (ID) has not been investigated. Methods Clinical and radiologic results from patients undergoing LLIF in a single institution between 2007 and 2014 were evaluated retrospectively. Patients were divided into two groups: those presenting with excessive fluid (EF) in the facet joints on T2-MRI and those with a normal amount of facet fluid with less than 1mm, which were controls. Radiological parameters were foraminal height, disc height, Cobb angle, and lumbar lordosis. Results A total of 21 patients (43 operated levels) were evaluated pre- and postoperatively. Mean disc height, mean foraminal height, and coronal Cobb angles were statistically significantly improved after LLIF. Only the EF group showed significant improvement in radiological markers after ID; the mean disc height improved from 5.5±2 to 8.8±1mm (p=0.001), mean foraminal height improved from 16.88±3 to 20.53±3mm (p=0.002), and the mean Cobb angle improved from 27.7±16 to 14±13 (p=0.018). Conclusions Patients undergoing LLIF with the radiological findings of EF in the facet joints demonstrated significant improvement in radiological outcomes of ID. Further studies should validate these findings in larger data sets.

Outcome of autologous bone graft versus polyetheretherketone cages in anterior cervical discectomy and fusion surgery

Objective:To compare the outcome of autologous bone graft versus PEEK cages in ACDF surgery in terms of clinical performance and radiographic features.&#x0D; Methodology:This study was conducted at Department of Neurosurgery, Punjab Institute of Neurosciences, Lahore, Pakistan from April 2020 to December 2022. In this study patients were randomized into two equal groups i.e. Group A (autologous bone graft) and Group B (PEEK cage).&#x0D; Results: Total of 98 patients was included in the study. The mean age of cases was 49.88 ± 17.83 years. There were 58(59.18%) male and 40(40.82%) female cases. 25(25.51%) cases who had C3-C4 involved, 48(48.98%) patients had C5-C6 and 25(25.51%) cases had C5 region involved. The mean disc height at 6th months in PEEK group was 6.71 ± 0.46 mm and in bone graft group was 6.33 ± 0.47 mm, p-value &lt; 0.05. The mean operative time in PEEK group (2.07 ± 0.42) was statistically less than bone graft group (3.23 ± 0.36), p-value &lt; 0.05. The average blood loss was also statistically less in PEEK group as compared to bone graft. The mean hospital stay in PEEK group was 2.92 ± 0.61 days as compared to bone graft was 5.48 ± 1.90 days, p-value &lt; 0.05.&#x0D; Conclusion:Outcome of ACDF surgery PEEK cages are better than autologous bone graft in terms of clinical performance and radiological features. Hence PEEK cages can be opted in future to have better outcome and higher patient’s satisfaction.&#x0D;

72. Static vs expandable TLIF cage: a comparison of predicted and achieved restoration of intervertebral disc height

<h3>BACKGROUND CONTEXT</h3> In situ expandable TLIF cages have been shown effective in restoration of intervertebral disc and neuroforaminal height in minimally invasive surgery. However, prior studies have reported increased rates of radiographic subsidence with expandable cages, in part, related to presumed increased stress per surface area at the graft-bone interface upon distraction. A novel multidirectional expandable TLIF cage aims to increase axial fusion footprint to better distribute this stress and reduce subsidence. However, the relationship between predicted and actual disc height (DH) restoration upon physiologic loading between a static and expandable cage following MIS TLIF remains unclear. <h3>PURPOSE</h3> To evaluate and compare the predicted vs actual DH restoration following MIS TLIF using an expandable vs static cage. <h3>STUDY DESIGN/SETTING</h3> A single-center retrospective review of 137 consecutive adult patients undergoing 1- or 2-level MIS TLIF were divided between an expandable cage cohort (ECC, n=83) vs static caged cohort (SCC, n-54). Predicted DH restoration was calculated based on cage height. DH was assessed by upright X-ray before, immediately following and one year postsurgery. <h3>PATIENT SAMPLE</h3> A single-center retrospective review of 137 consecutive adult patients undergoing 1- or 2-level MIS TLIF. <h3>OUTCOME MEASURES</h3> Predicted DH restoration was calculated based on cage height. DH was assessed by upright X-ray before, immediately following and one year postsurgery. <h3>METHODS</h3> A single-center retrospective review of 137 consecutive adult patients undergoing 1- or 2-level MIS TLIF were divided between an expandable cage cohort (ECC, n=83) vs static cage cohort (SCC, n-54). Predicted DH restoration was calculated based on cage height. DH was assessed by upright X-ray before, immediately following and one year postsurgery. <h3>RESULTS</h3> One hundred thirty-seven patients representing 148 operative levels (mean age 63.7±11.3 years, 57.7% female) were included for analysis. Mean cage height in the SCC vs ECC was 10.3±1.6 mm and 10.8±1.7 mm, respectively. Preoperative mean DH were comparable at 7.1±0.3 mm and 7.6±0.2 mm in the SCC and ECC (p>0.05). A statistically significant difference in mean DH restoration favoring the ECC was obtained immediate postoperative with durable gains to 1-year postoperative (p0.05) <h3>CONCLUSIONS</h3> The expandable TLIF cage studied showed significantly better gains in DH restoration at the immediate postoperative to one year post surgery. At one year, significantly more patients maintained at least their predicted DH in the ECC, suggestive that an expandable cage may restore, maintain and achieve predicted DH better than a static cage following MIS TLIF. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

29. Imaging outcome at 24-month follow-up in a prospective, multicenter study of two-level cervical arthroplasty with a PEEK on ceramic artificial disc

<h3>BACKGROUND CONTEXT</h3> The use of cervical total disc replacement (cTDR) continues to increase. The implants continually evolve with respect to design and materials. Imaging studies of these devices provides insight to their ability to provide and maintain range of motion (ROM), disc height, and depending on the implant materials, facet joint assessment. <h3>PURPOSE</h3> The purpose of this study was to evaluate the imaging outcome of a PEEK-on-ceramic artificial disc for the treatment of two-level cervical disc disease. <h3>STUDY DESIGN/SETTING</h3> Data for this study came from a prospective, multicenter, non-randomized, historically controlled FDA Investigational Device Exemption (IDE) trial evaluating the Simplify®Cervical Artificial Disc for use at two levels. <h3>PATIENT SAMPLE</h3> Two-level cTDR was performed in 182 patients treated for symptomatic cervical disc degeneration with radiculopathy/myelopathy. <h3>OUTCOME MEASURES</h3> The primary outcome measures were ROM, disc height, and heterotopic ossification (HO) of the treated levels. MRI was used to assess the facet joints. <h3>METHODS</h3> The cTDR is composed of PEEK endplates with a mobile ceramic core. Radiographic evaluations were performed preoperatively, at hospital discharge, and 6 weeks, and 3, 6, 12, and 24 months postoperatively. MRI was performed pre- and 24 months postoperatively. All images were evaluated by an independent core lab. HO was evaluated based on a 0 (normal) to 4 (bridging bone) scale. Facets joints were scored on a 4-point scale ranging from 0 (normal) to 3 (severe degeneration) based on the MRI performed pre- and 24 months postoperatively. <h3>RESULTS</h3> At the superior cTDR level, the mean ROM improved from 8.0° prior to surgery to 9.5° at 24-month follow-up. At the inferior level, the values were 6.6° and 8.9°, respectively. At both operated levels, mean disc height increased postoperatively and the increase was maintained through 24-month follow-up. At the superior index level, the preoperative mean height was 3.1 mm and at 24 months it was 4.3 mm. At the inferior index level, the preoperative height was 3.1 mm and was 4.0 at 24 months. HO rates at 24-month follow-up were, the superior index level, severe HO (Grade 3) occurred in 8 patients (5%). Bridging HO (Grade 4) was also seen in 8 patients (5%). At the inferior index level, severe and bridging HO was seen in 17 (10%) and 5 (3%) patients, respectively. There was a lack of facet degeneration progression assessed on MRI between pre- and 24-month follow-up. No patient had severe facet degeneration at either operated level at either time point. The percentage of patients with a grade of moderate facet degeneration did not change at either level 8% at the superior index level and 5% at the inferior index level. At both levels, there appeared to be patients changing from the "none" category to the "mild" category. At the superior level prior to surgery, the figures for "none" and "mild" were 62% and 30% respectively. At 24-month follow-up, the figures were 52% and 39%, respectively. A similar pattern was seen at the inferior index level. <h3>CONCLUSIONS</h3> This study adds to the expanding evidence that two-level cTDR increases and maintains ROM and disc height and through 24-month follow-up. The majority of cTDR patients did not experience bridging HO. This PEEK-on-ceramic cTDR produces minimal artifact, allowing for reliable MRI visualization. This was used to evaluate the facet joints and a lack of facet degeneration progression was found. <h3>FDA DEVICE/DRUG STATUS</h3> Simplify Cervical Artificial Disc 2-level (Approved for this indication).

P133. Measuring the radiographic efficacy of indirect decompression following minimally invasive lumbar interbody fusion: a computed tomography (CT) analysis study

<h3>BACKGROUND CONTEXT</h3> The advancement of MIS techniques has led to increased reliance on indirect decompression techniques. The latest generation of MIS TLIF cages are typically expandable cages that restore disc height and achieve ligamentum flavum unbuckling with associated increased central canal area. While prior studies have measured the extent of indirect decompression associated with ALIF and LLIF, the degree of decompression achieved via MIS-TLIF has not been described. <h3>PURPOSE</h3> Assess the degree of indirect decompression following minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). <h3>STUDY DESIGN/SETTING</h3> Single-center, multi-surgeon, retrospective review. <h3>PATIENT SAMPLE</h3> Patients undergoing MIS-TLIF without direct decompression between 3/2017 and 3/2021. Patients were included if they had a pre- and postoperative CT scan. <h3>OUTCOME MEASURES</h3> Pre- and postoperative CT scans were used to measure disc height, foraminal area (left and right) and central canal area at the operative level(s). The most recent postoperative patient reported outcome measures (PROMs) between 6 months and 2 years were used to compare against preoperative values. <h3>METHODS</h3> Postoperative CT was performed at 1-43 months based on surgeon-specific protocols. Both pre- and postoperative CT measurements were performed by two observers. PROMs were collected in a prospectively maintained database. Paired tests were used to compare changes in CT measurements and PROMs. Bivariate analysis was also done to assess correlations between the changes in CT measures and PROMs improvement. <h3>RESULTS</h3> A total of 40 patients (48 operative levels) were assessed; 16 (33.3%) of the subjects were female and 24 (50%) were male. The average age was 56.6 ± 15.9 years. The average length of follow-up was 17.9 ± 7.9 months for PROMs and 13.5 ± 9.3 months for postoperative CT imaging. There were 32 (80%) single-level and 8 (20%) two-level cases, with 23 (47.9%) operated at L4L5 and 25 (52.1%) at L5S1. Disc height, foraminal area, and central canal area all increased significantly (p < 0.001). Mean disc height increased 50%, from 4.2 to 6.3mm. Right sided foraminal area increased 23%, from 144 .5 to 177.8mm2, the left increased 21.4% from 142.8 to 173.4mm2, and the central canal increased 16.4% from 228.6 to 266 mm2. All PROMs except for SF12-MCS (p=0.439) showed a statistically significant improvement (p < 0.05). There was no correlation between each change in PROM and the increase in cross sectional canal area. <h3>CONCLUSIONS</h3> MIS-TLIF provides a significant degree of indirect decompression. Disc height, foraminal area and central canal area were all increased following insertion of the interbody cage via the MIS-TLIF technique. PROMs by 2 years demonstrated a statistically significant improvement. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

English

BACKGROUND In this study we wanted to test hypothesis that posterior ligament complex preserving decompression has advantages over conventional decompression surgeries for the treatment of lumbar canal stenosis, assess clinical and functional outcome following decompression surgeries whether preservation has advantages over routine decompression and use radiological parameters pre operatively and post operatively to evaluate whether there is adjacent segment degeneration following decompression surgeries for canal stenosis. METHODS This is a prospective study conducted among in-patient and outpatient follow ups of the Department of Orthopaedics of MIMS Hospital, Calicut, over a period of 22 months from February 2017 to November 2018. RESULTS The mean age of patients included in the study in PLC preserved group was 58.68 ± 11.3 years and in PLC non-preserved group, it was 62.75 ± 11.18 years. There was a slight female predominance in PLC preserved group (60 %) and in PLC non preserved group male to female ratio was 1:1 At 1 year follow up both the groups of patients had significant relief of symptoms and had improved functional outcome. At 1 year follow up ODI and VAS score were better in PLC preserved group compared with PLC not preserved group. There was adjacent segment disc height improvement in both the groups, and was maintained in the PLC preserved group while during the final follow up there was slight reduction in the mean disc height in PLC not preserved group. Intervertebral disc angle and total lumbar lordosis in both the groups were comparable during 1 year follow up. Adjacent segment slip was not noted in both the groups. Adjacent segment degeneration was not detected in both the groups. CONCLUSIONS Lumbar decompressive surgeries with both PLC preserving and non-preserving surgeries can provide significant relief of symptoms to the patient. PLC preserving surgeries provide better functional outcome during the 1 year follow up period. Similarly residual pain was also less in the PLC preserved group. Adjacent segment degeneration was not detected in both the groups during the one year follow up. KEY WORDS Posterior Ligamentous Complex, Decompressive Surgeries, Lumbar Spinal Canal Stenosis

Comparison of surgical outcomes between oblique lateral interbody fusion (OLIF) and anterior lumbar interbody fusion (ALIF)

ObjectiveAlthough oblique lateral interbody fusion (OLIF) utilizes the similar approach in anterior lumbar interbody fusion (ALIF), OLIF is essentially a lateral lumbar interbody fusion (LLIF). Therefore, OLIF may have advantages in LLIF that the lateral cage can achieve greater restoration of the disc height and angle. We aimed to compared the surgical outcomes between OLIF and ALIF. MethodsThis study involved 47 consecutive patients who underwent a single-level OLIF and 45 consecutive patients who underwent a single-level ALIF at L2-L5 levels. Radiological measurements included the changes of anterior/posterior disc height, coronal/sagittal disc angle, foramen cross-sectional area (CSA), cage position from the anterior margin of the lower vertebra, fusion rate, and cage subsidence using the serial radiographs and computed tomography preoperatively and at the postoperative 1-year follow-up. Clinical outcomes were assessed by visual analog scale (VAS) for back/leg pain, Oswestry disability index (ODI), and the occurrence of perioperative complications. ResultsThe baseline radiological and clinical parameters were similar between the OLIF and ALIF groups (all P > 0.05). At postoperative 1 year, the mean anterior disc height was higher in the OLIF group than the ALIF group (11.4 ± 1.9 mm vs. 9.6 ± 2.6 mm, P = 0.021). The mean sagittal disc angle was also greater in the OLIF group than the ALIF group (10.9 ± 4.4° vs. 8.9 ± 5.8°, P < 0.001). The mean cage position was 5.8 ± 2.1 mm in the OLIF group and 8.7 ± 2.3 mm in the ALIF group (P < 0.001). There was no difference in the postoperative changes of coronal disc angles, foramen CSA, fusion rate, cage subsidence, VAS for back/leg pain, ODI, and the occurrence of perioperative complications between the OLIF and ALIF groups (all P > 0.05). ConclusionsOLIF showed a greater increase in disc height and segmental lordosis than ALIF with comparable complications. OLIF is a meaningful progress from ALIF.