Preoperative Disc Degeneration Research Articles

Impact of Preoperative Intervertebral Disc Degeneration on Patient-Reported Outcome Measures After Lumbar Fusion

The Pfirrmann scoring system classifies lumbosacral disc degeneration based on MRI signal intensity. The relationship between pre-existing disc degeneration and PROMs after one-level lumbar fusion is not well documented. The purpose of this study was to investigate the relationship between the severity of preoperative intervertebral disc degeneration and pre- and postoperative patient-reported outcome measures (PROMs) in patients undergoing one-level lumbar fusion. All adult patients underwent posterior lumbar decompression and fusion (PLDF) or transforaminal lumbar interbody fusion (TLIF) between 2014-2022 were included. Patient demographics, and comorbidities were extracted from medical records. Lumbar intervertebral discs on sagittal MRI T2-weighted images were assessed by two independent graders utilizing Pfirrmann criteria. Grades I-III were categorized as low-grade disc degeneration, while IV-V were considered high-grade. Multivariable linear regression assessed the impact of disc degeneration on PROMS. A total of 150 patients were included, of which, 69 (46%) had low grade disc degeneration, while 81 (54%) had high grade degeneration. Patients with high-grade degeneration had increased preoperative VAS-Leg scores (6.10 vs. 4.54, p=0.005) and displayed greater one-year postoperative improvements in VAS-Back scores (-2.11 vs -0.66, p=0.002). Multivariable regression demonstrated Pfirrmann scores as independent predictors for both preoperative VAS-Leg scores (p=0.004) and postoperative VAS-Back improvement (p=0.005). In patients undergoing one-level lumbar fusion, higher Pfirmann scores were associated with increased preoperative leg pain and greater one-year postoperative improvement in back pain. Further studies into the relationship of pre-operative disc degeneration and their impact on postoperative outcomes may help guide clinical decision making and patient expectations.

The Fate of Pre-Existing L5-S1 Degeneration following Oblique Lumbar Interbody Fusion of L4-L5 and Above

Background: Previous studies have identified various risk factors for adjacent segment disease (ASD) at the L5-S1 level after fusion surgery, including preoperative sagittal imbalance, longer fusion, and preoperative disc degeneration. However, only a few studies have explored the risk factors for ASD at the L5-S1 level after oblique lumbar interbody fusion (OLIF) at the L4-L5 level and above. This study aimed to identify the risk factors for symptomatic ASD at the L5-S1 level in patients with pre-existing degeneration after OLIF at L4-L5 and above. Methods: We retrospectively reviewed the data of patients who underwent OLIF at L4-L5 and above, with a minimum follow-up period of 2 years. Patients with central stenosis or Lee grade 2 or 3 foraminal stenosis at L5-S1 preoperatively were excluded. Patients were divided into ASD and non-ASD groups based on the occurrence of new-onset L5 or S1 radicular pain requiring epidural steroid injection (ESI). The clinical and radiological factors were analyzed. Logistic regression was used to identify the risk factors for ASD of L5-S1. Results: A total of 191 patients with a mean age ± standard deviation of 68.6 ± 8.3 years were included. Thirty-four (21.7%) patients underwent ESI at the L5 root after OLIF. In the logistic regression analyses, severe disc degeneration (OR (95% confidence interval (CI)): 2.65 (1.16–6.09)), the presence of facet effusion (OR (95% CI): 2.55 (1.05–6.23)), and severe paraspinal muscle fatty degeneration (OR (95% CI): 4.47 (1.53–13.05)) were significant risk factors for ASD in L5-S1. Conclusions: In this study, the presence of facet effusion, severe disc degeneration, and severe paraspinal muscle fatty degeneration at the L5-S1 level were associated with the development of ASD at L5-S1 following OLIF at L4-L5 and above. For patients with these conditions, surgeons could consider including L5-S1 in the fusion when considering OLIF at the L4-L5 level and above.

The analysis of progression of disc degeneration in distal unfused segments and evaluation of long-term functional outcome in adolescent idiopathic scoliosis patients undergoing long-segment instrumented fusion.

To analyse the progression of disc degeneration in distal unfused lumbar segments in post-operative Adolescent Idiopathic Scoliosis (AIS) patients; and to evaluate pre-operative and post-operative radiological parameters associated with progressive disc degeneration. A retrospective study of patients, who underwent surgery for AIS between 2006 and 2013 at a tertiary-care spine hospital, was conducted. Only patients aged between 11 and 18years, who underwent deformity correction surgery with pedicle screw-only constructs, minimum of 6.5year follow-up, and complete radiological data, and were included. On plain radiographs, coronal cobb's angle (CCA), apical translation, lower instrumented vertebra tilt (LIV tilt), LIV-Sacral angle, and sagittal spinal and pelvic parameters were measured. Disc degeneration was assessed on Magnetic Resonance Imaging (MRI) using Pfirrmann's grading. Total endplate score (TEPS) and facet degeneration (by Fujiwara's grading) were also measured. Based on the difference in progression of disc degeneration, patients were classified as Pfirrmann's grade static (PGS) and Pfirrmann's grade progressive (PGP) groups. Comparison of all pre- and post-operative parameters was made between PGS and PGP groups, and statistically analyzed. Functional evaluation was performed using SRS-22 score. A total of 58 patients were finally included. The mean follow-up was 9.1years. 43 (74.1%) and 15 (25.9%) patients were classified under PGS and PGP groups, respectively. Among the15 patients in PGP group, selected LIV was L4 in 8, L3 in 3, L1 in 3, and L2 in 1. Among them, 11 patients (73.3%) progressed from grade 1 to grade 2. In the remaining 4 (26.6%), Pfirrmann's grade progressed to ≥ 3. The progression of disc degeneration did not correlate with age or sex distribution (p = 0.3), pre-operative and post-operative TEP scores (p = 032), pre-operative disc or facet degeneration (p = 0.52), number of unfused spinal segments (p = 0.56), pre-operative or post-operative coronal (p = 0.42), or sagittal spinal (p = 0.27) or pelvic parameters (p = 0.14). The final functional outcome (SRS-22) was not significantly different between PGS and PGP groups (p = 0.67). 74% of AIS patients demonstrated no signs of progressive disc degeneration at an average follow-up of 9.1years. 26% (15/58) of AIS patients demonstrated progressive disc degeneration, among whom, degeneration progressed by only 1 Pfirrmann's grade in 74% (11/15). In the remaining four patients, disc degeneration progressed to Pfirrmann's grades 3 or greater. There was no correlation between higher grades of disc degeneration and lower instrumented vertebra (LIV) or functional outcomes scores (SRS-22).

An independent agreement study of modified Pfirrmann grading system for cervical inter-vertebral disc degeneration in cervical spondylotic myelopathy

Objective Neck pain, sensory disturbance and motor dysfunction in most patients suffered cervical spondylotic myelopathy (CSM). For CSM surgery, it is necessary to evaluate preoperative inter-vertebral disc degeneration (IDD) which determines whether to adopt fusion strategy, and postoperative IDD which is one of the main reasons for reoperation. Modified Pfirrmann grading system is commonly used to evaluate IDD. The objective of this study is to evaluate its reliability and reproducibility on cervical IDD in CSM patients, and to explore its clinical application value. Methods All 165 patients with CSM were enrolled. 6 physicians (3 spine surgeons and 3 radiologists) who have certain clinical experience were selected. They graded cervical inter-vertebral disc according to modified Pfirrmann grading system, we used intra-class correlation coefficient (ICC) and weighted kappa (wκ) to assess the inter- and intra-observer agreement. After 12 weeks, we repeated the analysis. Results The inter-observer reliability of modified Pfirrmann grading system was excellent with an ICC value of 0.76 and near perfect with wκ value of 0.82. The intra-observer reproducibility of modified Pfirrmann grading system was excellent with ICC values ranging from 0.80 to 0.91, and near perfect with wκ values ranging from 0.83-0.92. Conclusion Modified Pfirrmann grading system has excellent inter-observer reliability and intra-observer reproducibility on cervical IDD in CSM. In addition, it indicates a good appliance among spine surgeons and radiologists, clinical and radiological studies applying it should be deemed accurate. Thus, modified Pfirrmann grading system can be widely used as an appropriate instrument in clinical care.

Effects of Restoration of Sagittal Alignment on Adjacent Segment Degeneration in Instrumented Lumbar Fusions.

Retrospective case-control study. To investigate the effects of postoperative sagittal alignment on radiographic adjacent segment degeneration (ASD) after lumbar fusion surgery. ASD is one of inherent problems with fusion surgery. Many confounding factors are related to the development of ASD. Recently, sagittal alignment has been emphasized for its significance on ASD. Seventy-three patients who underwent four-level lumbar fusion surgery (L2-S1) were divided into two groups according to postoperative sagittal alignment (pelvic incidence-lumbar lordosis [PI-LL] ≥ or <9°): 44 patients (matched group, including 10 patients who underwent pedicle subtraction osteotomy [PSO] at L4) and 29 patients (mismatched group). The general demographics, radiographic parameters, and clinical outcomes were recorded. Preoperative disc degeneration at L1-2 was evaluated by Pfirrmann grade and Kellgren-Lawrence (K-L) grade. Disc degeneration at L1-2 was evaluated by the K-L grade on 2-year postoperative X-rays. The incidence of radiographic ASD (11 [25%] vs. 16 patients [55%], P = 0.02) and Oswestry Disability Index (ODI) scores (36.9 ± 19.9 vs. 49.4 ± 20.7, P = 0.015) at postoperative 2 years were significantly higher in the mismatched group. There were no significant differences in other demographic and radiographic parameters between the two groups. On subgroup analysis between 10 PSO patients and the mismatched group, the mismatched group showed a higher incidence of radiographic ASD (16 [55%] vs. 1 patient [10%], P = 0.041) and worse ODI scores (49.7 ± 20.5 vs. 39.0 ± 20.7, P = 0.040). Preoperative Pfirrmann grade at L1-2 (odds ratio [OR] = 4.191, 95% confidence interval [CI]: 1.754-10.013, P = 0.001) and postoperative PI-LL mismatch (OR = 4.890, 95% CI: 1.550-15.427, P = 0.007) showed significant relationships with the development of radiographic ASD at postoperative 2 years. The restoration of optimal sagittal alignment, even with PSO, may provide a protective effect on the development of radiographic ASD, although the preoperative disc degeneration grade was a risk factor for radiographic ASD. 3.

Predictors of Treatment Success Following Limited Discectomy With Annular Closure for Lumbar Disc Herniation.

Previous studies have demonstrated bone-anchored annular closure to significantly reduce reherniation and reoperation rates after lumbar discectomy in patients with large annular defects. It is important to identify the prognostic factors that may be associated with successful treatment. This study aimed to identify predictors of treatment success in patients with lumbar disc herniation treated with limited microdiscectomy supplemented by a bone-anchored annular closure device (ACD). This study was a retrospective analysis of 133 consecutive patients with lumbar disc herniation treated with the ACD. Treatment success was defined as ≥24% improvement in visual analog scale (VAS) for back pain, ≥39% improvement in VAS leg pain, and ≥33% in the Oswestry Disability Index (ODI), with the raw ODI score ≤48. Success was calculated at 3, 6, and 12 months after surgery. Potentially predictive outcomes included patient characteristics, operative data, and imaging outcomes, such as disc, facet, and end plate morphology. Logistic regression was used to determine the significant predictive factors for treatment success. After 3, 6, and 12 months, 97 of 131 (74%), 104 of 129 (81%), and 112 of 126 (89%) patients, respectively, achieved the success criteria. At 3 months follow-up, a higher proportion of younger (17-40 years) versus older (41-65 years) patients met the success criteria (P = .025). On the basis of logistic regression, the following factors were significantly associated with treatment success at 1 or more of the follow-up time points: sex (male), lower body mass index, higher baseline pain and ODI scores, lower grade preoperative disc degeneration, and the absence of a postoperative complication. The rates of index-level recurrent herniation and reoperation were 1.5% and 3.0%, respectively. This real-world evidence supports a promising benefit-risk profile for augmenting limited microdiscectomy with a bone-anchored ACD and provides some insights into the patient populations that may have a greater chance of realizing significant improvements in pain and function. 2 (Cohort study).

120. Can hybrid constructs prevent adjacent segments degeneration? Long-term follow-up results

BACKGROUND CONTEXT Adjacent segment degeneration (ASD) is a common complication after lumbar spine fusion. The incidence was reported up to 50% radiographic or 30% symptomatic at 7 years. ASD sometimes leads to revision surgery. PURPOSE Hybrid fusion dynamic stabilizer was designed to prevent adjacent segment degeneration by the topping-off technique. The aim of this study was to evaluate the long-term results of this hybrid construct. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE Patients receiving a hybrid construct (HPSTM, Paradigm) for lumbar degenerative disease from Jan. 2013 to Jan. 2016 were included in our series. A total 30 patients were enrolled in our series (4 are excluded due to no postoperative MRI available). At the same time period, 223 patients who underwent lumbar spine fusion were used as a control group. OUTCOME MEASURES The protection of the index level (dynamic segment) in the hybrid group was evaluated by a follow-up MRI, which was graded as good (disc bulging reversal), stationary (no change), and failed (degeneration progressed). The occurrence of supra-adjacent segment degeneration (ASD) was assessed by the last follow-up plain film. We evaluated the disc and body next to the hybrid construct. The definition of ASD included disc height decreased more than 50%, presence of vacuum disc, development of retrolisthesis or spondylolisthesis, and compression fracture. METHODS The incidence of ASD and revision surgery was compared statistically between hybrid and fusion group. RESULTS The age, sex, and numbers of segments receiving instrumentation, were all comparable in both groups. The mean follow-up time was 50.4 months. For the hybrid group, 22 patients received one fusion and one dynamic fixation. The other 8 patients underwent 2 fusions and one dynamic fixation. For index level degeneration protection, 12 was graded as good, 17 as stationary and one as poor. ASD occurred in 7 patients (23.3%), one in the inferior segment and 6 in the superior segment. Three patients received revision surgery (10%): 2 for severe ASD and one for screw loosening. The incidence of ASD and revision surgery showed no statistical difference between hybrid and fusion group (23.3% vs 26.5%, 10% vs 13%). CONCLUSIONS The hybrid construct prevents index level degeneration. However, the incidence of ASD next to the construct is still high. It has a similar incidence of ASD and reoperation as compared with the fusion group. The dynamic level may become fused in long-term follow-up. This construct should be used in caution especially when there is preoperative disc degeneration next to the instrumentation level. FDA DEVICE/DRUG STATUS HPS, paradigm (Approved for this indication).

Effect of pre-existing adjacent segment degeneration on short-term effectiveness after lumbar fusion surgery

To analyze the prospective effect of pre-existing spinal stenosis of adjacent segment on the short-term effectiveness after lumbar fusion surgery. A prospective comparative study was conducted to divide 183 patients with L 4-S 1 lumbar spinal stenosis who met the selection criteria between July 2015 and December 2017 into two groups according to the status of adjacent segment degeneration (ASD) judged by preoperative disc degeneration and spinal stenosis. There were 98 patients in group A (no degeneration of adjacent segments before operation) and 85 patients in group B (adjacent segments degenerated before operation). There was no significant difference in gender, American Society of Anesthesiologists (ASA) grade, body mass index (BMI), combined spondylolisthesis, and preoperative visual analogue scale (VAS) score of low back pain and leg pain, Japanese Orthopaedic Association (JOA) score, and Oswestry disability index (ODI) score between the two groups ( P>0.05); the age of group A was significantly younger than that of group B ( t=-3.560, P=0.000). The operation time, intraoperative blood loss, hospitalization stay, and perioperative complications were recorded and compared. The VAS score of low back pain and leg pain, JOA score, and ODI score at last follow-up were used to evaluate the effectiveness. The incidence of ASD after operation was compared between the two groups, and logistic regression was used to analyze the independent risk factors affecting the occurrence of ASD after operation. There was no significant difference in operation time, intraoperative blood loss, and hospitalization stay between the two groups ( P>0.05). The incidence of perioperative complications in groups A and B was 13.3% and 20.0%, respectively, with no significant difference ( χ 2=1.506, P=0.220). Two groups of patients were followed up, the follow-up time of groups A and B was (24.9±8.8) months and (24.8±7.8) months, respectively, there was no significant difference ( t=0.050, P=0.960). At last follow-up, no adjacent segment disease was found in either group. There was no significant difference in Pfirrmann grade between the two groups at last follow-up ( P>0.05), and there was significant difference in Pfirrmann grade between the two groups before operation and at last follow-up ( P<0.001). At last follow-up, 21 cases (21.4%) in group A and 53 cases (62.4%) in group B had ASD, with significant difference ( χ 2=31.652, P=0.000). The main cause of ASD was the severity of adjacent spinal canal stenosis. The clinical scores of the two groups at last follow-up were significantly improved when compared with those before operation ( P<0.05). The JOA score of group A was significantly higher than that of group B at last follow-up ( P<0.05). In group B, the VAS score of low back pain and ODI score in patients with ASD after operation at last follow-up were significantly higher than those in patients without ASD ( P<0.05). logistic regression analysis showed that preoperative pre-existing degeneration and BMI were independent risk factors for ASD after operation ( P<0.05). Pre-existing mild spinal stenosis in adjacent segment can significantly affect the effectiveness, and can significantly increase the risk of ASD early after operation. The main pathological type of ASD was the severity of adjacent segment spinal stenosis. For preoperative assessment of pre-existing degeneration, we should evaluate the overall degeneration of the adjacent segment of the spinal canal, rather than simply evaluating the degeneration of the adjacent disc and facet joints.

Adjacent segment disease after posterior lumbar instrumentation surgery for degenerative disease: Incidence and risk factors.

To identify risk factors for occurrence of symptomatic adjacent segment disease (ASD) after posterior lumbar instrumentation surgery. This retrospective study evaluated 630 patients who underwent posterior lumbar transpedicular instrumentation for degenerative lumbar disorders between April 2008 and April 2012. On the basis of developing ASD at follow-up, patients were categorized into two groups: the ASD group and the non-ASD (N-ASD) group. These two groups were compared for patient characteristics, surgical variables, and radiographic parameters to investigate the possible predictive factors of ASD. Of the 630 individuals participated in the study, 76 (12.1%) patients had ASD. Mean and standard deviation of age were 61.37 ± 4.12 years for the ASD group and 62.37 ± 3.9 for the N-ASD group ( p = 0.79). The average follow-up period was 51 ± 2.2 months in the ASD group and 52 ± 2.3 months in the N-ASD group ( p = 0.691). There were no significant differences between the two groups in terms of gender, diabetes mellitus (DM), hypertension, smoking, and osteoporosis, with all p > 0.05. The logistic regression analysis demonstrated that higher preoperative body mass index (BMI; odds ratio (OR) 1.233, p = 0.005), preoperative disc degeneration (OR 1.033, p = 0.024), decreased postoperative lumbar lordosis (OR 3.080, p = 0.011), fusion at more than four levels (OR 4.280, p = 0.014), and intraoperative superior facet joint violation (OR 7.480, p = 0.009) were independently associated with ASD. Patients with higher preoperative BMI, preoperative disc degeneration, decreased postoperative lumbar lordosis, fusion at more than four levels, and intraoperative superior facet joint violation have a statistically significant increased risk of developing ASD.

Preoperative Risk Factors for Adjacent Segment Degeneration after Two-Level Floating Posterior Fusion at L3-L5.

Introduction The aims of this study were to investigate how adjacent segment degeneration (ASD) occurs at the proximal and distal segments after L3-L5 fusion surgery, namely, floating fusion, and to identify the risk factors for ASD in patients who undergo this surgery. Methods Fifty patients who underwent floating fusion surgery at vertebrae L3-L5 and developed ASD were enrolled. The following parameters were evaluated: body mass index (BMI), diabetes status, dialysis status, lumbar lordosis, segmental lordosis between the L2 upper endplate and the L3 lower endplate, disc height, Cobb's angle, apical vertebral rotation using the Nash and Moe classification method, preoperative disc degeneration, surgical procedures, and the upper instrumented vertebra (UIV) tilt angle. The UIV tilt angle was defined as positive when the anterior side was directed caudally. Results Twenty-two (44%) of the 50 patients showed cephalad radiographic ASD (RASD) and 5 patients (10%) showed caudad RASD. Clinically symptomatic ASD was found at L2-L3 in 4 patients (8%) and at L5-S1 in 2 patients (4%). All the patients with clinically symptomatic cephalad ASD underwent revision procedures for radiculopathy or claudication because of degenerative pathology at L3-L4. Multivariate regression analysis showed a significant association of the absolute value of UIV tilt angle (mean |UIV tilt|) with cephalad RASD (odds ratio 1.09, p = 0.038). Receiver-operating characteristic curve analysis showed a significant association of |UIV tilt| >10.3° with RASD (sensitivity 67.9%, specificity 77.3%, area under the curve [AUC] 0.675). Conclusions RASD was more likely to occur at the adjacent segment on the cephalad side than at the adjacent segment on the caudad side after two-segment floating fusion of L3-L5. A preoperative UIV tilt angle >10° or UIV tilt < −10° was a risk factor for RASD.

Postoperative MRI findings 5years after lumbar microdiscectomy.

Lumbar microdiscectomy is a common procedure with satisfactory results; however, postoperative events like progressive adjacent level degeneration and perineural fibrosis can contribute to long-term pain. The purpose of the study was to evaluate MRI changes 5years after lumbar microdiscectomy and assess their association with clinical parameters. A prospective study enrolling 61 patients who underwent microdiscectomy. Changes between preoperative and postoperative MRI findings were recorded, and these findings were tested for associations with demographic, clinical and perioperative parameters. The measured imaging parameters were degeneration of the operated and adjacent discs and endplates, morphology of the disc herniation, facet joints arthritis and the presence of postoperative perineural fibrosis. Statistically significant differences were found between preoperative and postoperative morphology of the operated disc, facet joints arthritis and degeneration of the operated and caudal adjacent disc. There were no differences between preoperative and postoperative disc degeneration of the superior adjacent disc and in degeneration of the operated and adjacent endplates. Postoperatively perineural fibrosis was common; however, thecal sac compression and nerve root impingement were reduced. Age at the time of surgery was the only parameter associated with postoperative changes. Five years after microdiscectomy, several postoperative MRI changes including operated disc's morphology, facet joints arthritis and degeneration of the operated and caudal adjacent disc were shown. Taking into consideration that participants were on average middle-aged, these changes could be attributed not only to the impact of the surgery but also to the natural history of lumbar spine degeneration.

Surgical Outcomes After Segmental Limited Surgery for Adjacent Segment Disease: The Consequences of Makeshift Surgery.

To minimize surgical morbidity, surgeons may opt to perform segmental limited surgery instead of fusion extension for adjacent segment disease (ASD) after lumbar fusion surgery. This study evaluated clinical outcomes from segmental limited surgery without fusion extension for ASD and assessed which clinical factors were associated with reoperation after segmental limited surgery. Medical data of 50 patients who underwent segmental limited surgery for ASD after lumbar fusion surgery between 2005 and 2015 were reviewed. Demographic data, ASD type, preoperative disc and facet degeneration, ASD location, and surgical summary were collected. The primary outcome was reoperation rate at 24 months after surgery. Of patients, 28 (56%) experienced recurrent radiculopathy (visual analog scale score ≥4). Revision surgery was performed in 22 patients (44%). Reoperation was performed more frequently in multilevel fusion first-surgery cases (15/23; 65.2%) than single-level fusion first-surgery cases (7/27; 25.9%; P= 0.005). The lowermost mobile segment group had a lower reoperation-free survival rate than the other group (hazard ratio= 9.85, 95% confidence interval 1.32-73.54, P= 0.01 [log-rank]). The 2-year reoperation-free survival rate for the lowermost mobile segment group was 31.5%, whereas the rate for the other group was 83.3%. Segmental limited surgery as a treatment for ASD after lumbar fusion surgery is likely to fail frequently and result in a high rate of recurrent radiculopathy and revision surgery. Fusion extension surgery is especially recommended for ASD at the lowermost mobile segment owing to the high failure rate.

Incidence and risk factors of adjacent segment disease following posterior decompression and instrumented fusion for degenerative lumbar disorders.

The purpose of this study was to explore incidence and risk factors of adjacent segment disease (ASD) following posterior decompression and instrumented fusion for degenerative lumbar disorders, and hope to provide references in decision making and surgical planning for both spinal surgeon and surgically treated patients.By retrieving the medical records from January 2011 to December 2013 in our hospital, 237 patients were retrospectively reviewed. According to the occurrence of ASD at follow up, patients were divided into 2 groups: ASD and N-ASD group. To investigate risk values for the occurrence of ASD, 3 categorized factors were analyzed statistically: Patient characteristics: age, sex, body mass index (BMI), bone mineral density (BMD), duration. Surgical variables: surgical strategy, number of fusion level, surgery segment, surgery time, blood loss, intraoperative superior facet joint violation. Radiographic parameters: preoperative lumbar lordosis, preoperative angular motion at adjacent segment, preoperative adjacent segment disc degeneration, preoperative paraspinal muscle degeneration.Postoperative ASD was developed in 15 of 237 patients (6.3%) at final follow up. There was no statistically significant difference between the 2 groups in patient characteristics of age, sex composition, BMD, duration, while the BMI was higher in ASD group than that in N-ASD group. There was no difference in surgical variables of surgical strategy, number of fusion level, surgery segment, surgery time, blood loss, while intraoperative superior facet joint violation was more common in ASD group than that in N-ASD group. There was no difference in radiographic parameters of preoperative lumbar lordosis, preoperative paraspinal muscle degeneration, while preoperative adjacent segment disc degeneration were more severe in ASD group than that in N-ASD group. The Logistic regression analysis revealed that, BMI >25 kg/m2, preoperative disc degeneration, and superior facet joint violation were independently associated with ASD.In conclusion, higher BMI, preoperative disc degeneration at adjacent segment and intraoperative superior facet joint violation are risk factors for ASD. Patients who are overweight or obesity and with preoperative disc degeneration at adjacent segment should be fully informed the risk of ASD. For surgeons, it is essential to prevent superior facet joint violation in pedicle screw insertion procedure.

Transverse decompression technique in the surgical treatment of degenerative lumbar canal stenosis

The aim of this study was to assess the outcomes of fusion technique via posterior instrumentation in combination with transverse decompression in the surgical treatment of degenerative lumbar canal stenosis. Forty-five patients-39 women (86.7%) and 6 men (13.3%)-were included. Mean age was 58.68±8.63 years with mean follow-up of 51.71±20.96 months. Preoperative and postoperative clinical evaluation was performed using the Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) for overall pain. Preoperative and postoperative imaging studies were used to measure the degree of spondylolisthesis and the angle of scoliosis and lumbar lordosis. The presence of preoperative facet joint arthrosis and changes in the diameter of anterior, posterior, and transverse spinal canal were assessed by computed tomography (CT). Preoperative disc degeneration, disk herniation, and spondylolisthesis were examined by magnetic resonance imaging (MRI). Mean preoperative ODI and VAS scores were 59.2% and 7.06, respectively, while postoperative ODI and VAS scores were 14.4% and 1.7%, respectively (p=0.001). Anteroposterior diameter of the central canal increased from 10.43±2.18 mm preoperatively to 19.63±2.01 mm postoperatively (p=0.0001). Mean preoperative and postoperative spondylolisthesis were 5.81±4.88 mm and 3.87±4.53 mm, respectively (p=0.0001). Mean preoperative and postoperative scoliosis angles were 5.84°±10.14° and 2.04°±5.08°, respectively (p=0.0002). Mean preoperative and postoperative lordosis angles were 22.47°±13.98° and 33.73°±10.89°, respectively (p=0.0001). Complications included pulmonary embolism in 1 patient (2.2%), superficial injury site infection in 1 patient (2.2%), and deep surgical site infection in 1 patient (2.2%). Two patients (4.4%) experienced dural tears. One patient (2.2%) had intraoperative radix damage. The results of the present study suggest that the fusion technique via posterior instrumentation, in combination with transverse decompression, offers a clinical improvement in patients with lumbar canal stenosis.

The significance of lumbar MRI in the diagnosis of recurrented lumbar disc herniation after surgery

To retrospectively evaluate the clinical evaluation of preoperative lumbar T2 sagittal MRI image in predicting the recurrent lumbar disc herniation (RLDH). Between January 2009 and April 2011, 28 patients were diagnosed as recurrent L4-5 disc herniation within 2.5 years after surgery, and 25 of them were included in the study as relapse group. At the same time, selected 25 patients implemented the same surgical methods in the same level as a control group randomly, they were all with good to excellent result and the follow-up time was at least 2.5 years. There was no statistical significance between the two groups in gender, age and body mass index(BMI) (P > 0.05). The lumbar MRI image of two groups of patients before surgery were collected and analyzed, with the disc degeneration grade classified. The χ(2) test was used to analyzed the difference of degeneration between the two groups of patients before surgery. Rank correlation analysis evaluated the correlation between disc degeneration and the period of time from the first operation to the recurrence. In terms of preoperative lumbar disc degeneration, there were 22 cases of low-grade disc degeneration and 3 cases of advanced disc degeneration in the relapse group and 5 cases and 20 cases respectively in the control group. there was significant difference between two groups (χ(2) = 23.27, P < 0.05), low-grade disc degeneration (gradesIand III) was significantly more frequent in the relapse group than in the control group. The patients with low-grade disc degeneration had a higher risk of recurrence, that was the risk of recurrent disc herniation increased by a factor of 4.4 from advanced disc degeneration to low-grade disc degeneration(OR = 4.4, 95%CI:1.983-9.765, P < 0.05). In cases of recurrence, the time interval between primary surgery and the recurrence of the patient with advanced disc degeneration was longer compared with low-grade disc degeneration (r = 0.733, P < 0.05). Preoperative lumbar MRI image may suggest the possibility of the recurrence lumbar disc herniation.Light disc degeneration is an important risk factor for recurrent disc herniation, and the time interval between primary surgery and the recurrence is positively correlated with severity of disc degeneration.

Risk factors for adjacent segment degeneration after surgical correction of degenerative lumbar scoliosis

Background:Degenerative lumbar scoliosis surgery can lead to development of adjacent segment degeneration (ASD) after lumbar or thoracolumbar fusion. Its incidence, risk factors, morbidity and correlation between radiological and clinical symptoms of ASD have no consensus. We evaluated the correlation between the occurrence of radiologic adjacent segment disease and certain imperative parameters.Materials and Methods:98 patients who had undergone surgical correction and lumbar/thoracolumbar fusion with pedicle screw instrumentation for degenerative lumbar scoliosis with a minimum 5 year followup were included in the study. We evaluated the correlation between the occurrence of radiologic adjacent segment disease and imperative patient parameters like age at operation, sex, body mass index (BMI), medical comorbidities and bone mineral density (BMD). The radiological parameters taken into consideration were Cobb's angle, angle type, lumbar lordosis, pelvic incidence, intercristal line, preoperative existence of an ASD on plain radiograph and magnetic resonance imaging (MRI) and surgical parameters were number of the fusion level, decompression level, floating OP (interlumbar fusion excluding L5-S1 level) and posterolateral lumbar interbody fusion (PLIF). Clinical outcomes were assessed with the Visual Analogue Score (VAS) and Oswestry Disability Index (ODI).Results:ASD was present in 44 (44.9%) patients at an average period of 48.0 months (range 6-98 months). Factors related to occurrence of ASD were preoperative existence of disc degeneration (as revealed by MRI) and age at operation (P = 0.0001, 0.0364). There were no statistically significant differences between radiological adjacent segment degeneration and clinical results (VAS, P = 0.446; ODI, P = 0.531).Conclusions:Patients over the age of 65 years and with preoperative disc degeneration (as revealed by plain radiograph and MRI) were at a higher risk of developing ASD.

Frequency, risk factors, and treatment of distal adjacent segment pathology after long thoracolumbar fusion: a systematic review.

Systematic review. To systematically review the literature related to distal adjacent segment pathology (ASP) after long thoracolumbar fusions for deformity including frequency, risk factors, frequency differences between adolescents and adults, surgical approach for revision, and revision complications. Spinal deformity surgery complications include ASP. Although ASP at the rostral end of instrumented fusions has been well described, substantially less has been documented about distal ASP. A systematic search was conducted in Medline and the Cochrane Collaboration Library for articles published between January 1, 1983, and March 15, 2012. We included all articles that described distal ASP after long thoracolumbar fusion for deformity. Radiographical ASP (RASP) was defined as evidence of ASP based on imaging, and clinical ASP (CASP) was defined as symptomatic ASP. Seven retrospective cohort studies met inclusion criteria. Distal CASP developed in 17.7% at 2- 6-year follow-up and 19.8% at 9-year follow-up, whereas reoperation due to CASP was reported in 15.6% at 2 to 6 years and 14.4% at 9 years. Distal RASP was more frequent (44.7%-65.5%). Preoperative sagittal imbalance was associated with increased risk of distal ASP. There was increased risk of CASP in patients with higher postoperative fractional curve and increased risk of RASP in younger patients and those with preoperative disc degeneration, longer fusions, circumferential procedures, and postoperative L5-S1 disc space narrowing. No studies meeting inclusion criteria compared distal ASP in adults and adolescents or defined the best approach or complications for distal ASP revision. Low-quality evidence suggests a cumulative rate of 18% to 20% for CASP and 45% to 65% for RASP after long thoracolumbar fusion for spinal deformity during 9-year follow-up. Low-quality evidence suggests an association between preoperative sagittal imbalance and distal ASP, with greater risk of distal ASP in patients with sagittal imbalance. Low-quality evidence suggests increased risk of CASP in patients with higher postoperative fractional curve and increased risk of RASP in younger patients and those with preoperative disc degeneration, longer fusions, circumferential procedures, and postoperative L5-S1 disc space narrowing. 1. The risk of developing new symptoms secondary to distal adjacent segment pathology following long thoracolumbar fusion for deformity is approximately 18–20% during a period of 9 years follow up, and most of these patients will require revision surgery. Strength of Statement: Weak. 2. The risk of developing distal adjacent segment pathology may be higher in those with preoperative sagittal imbalance, preoperative disc degeneration, longer fusions, circumferential procedures, and postoperative L5–S1 disc space narrowing. Strength of Statement: Weak.

Adjacent segment degeneration after instrumented posterolateral lumbar fusion: a prospective cohort study with a minimum five-year follow-up

To (1) clarify the role of various risk factors in the development of ASD, (2) compare instrumentation configuration with the development of ASD, (3) correlate the radiological incidence of ASD and its clinical outcome and (4) compare the clinical outcome between patients with radiological evidence of ASD and without ASD. This study prospectively examined 74 consecutive patients who underwent instrumented lumbar/lumbosacral fusion for degenerative disease with a minimum follow-up of 5years. Among the patients, 68 were enrolled in the study. All of the patients had undergone preoperative radiological assessment and postoperative radiological assessment at regular intervals. The onset and progression of ASD changes were evaluated. The patients were divided in two groups: patients with radiographic evidence of ASD (group 1) and patients without ASD changes (group 2). Comprehensive analysis of various risk factors between group 1 and group 2 patients was performed. The Visual Analog Scale (VAS) was used to evaluate the clinical outcome and the functional outcome was evaluated using the Oswestry Disability Index (ODI) before and after surgery along with radiological assessment. Radiographic ASD occurred in 20.6% (14/68) of patients. Preoperative disc degeneration at an adjacent segment was a significant risk factor for ASD. Other risk factors such as the age of a patient at the time of surgery, gender, preoperative diagnosis, length of fusion, instrumentation configuration, sagittal alignment and lumbar or lumbosacral fusion were not significant risk factors for the development of ASD. There was no correlation between ASD and its clinical outcome as determined at the final follow-up session. In addition, clinical outcome of patients with ASD and without ASD were not comparable. Patients with preoperative disc degeneration at an adjacent segment were more at risk for the development of ASD. Other risk factors including instrumentation configuration were not significantly associated with ASD. There was no correlation between both the radiological development of ASD and its clinical outcome and the clinical outcome of patients with and without ASD.

Radiologic Adjacent Segment Degeneration: Two Levels fusion (L3-4-5 and L4-5-S1) Using Percutaneous Pedicle Screw Fixation in Degenerative Lumbar Spinal Disease; A Preliminary Report

Objective: The purpose of this study is to examine radiological adjacent segment degeneration (ASD) and clinical results after two levels percutaneous pedicle screw fixation. Methods: From 2007 to 2009, 34 patients who underwent percutaneous pedicle screw fixation on L3-4-5 or L4-5-S1 for lumbar degenerative disorders were selected. According to the presence of radiological ASD, ASD group and non-ASD group were compared for clinical results and radiologic results such as total lordotic angle (TLA), segmental lordotic angle (SLA) via lumbar X-rays during follow up periods. Furthermore, we compared pre-operative degree of disc degeneration at adjacent segment between two groups via MRI. Results: The mean follow-up period and mean age were 27.38±9.45 months and 59.21±12.73 years. ASD group were 7 patients, and non-ASD group were 27 patients. The mean age of the ASD group (67.40±4.81) was significantly older than that of the non-ASD group (57.46±13.18). Pre-operative disc degeneration of cranial adjacent segment in ASD group were 6 patients (25.9%), whereas that in non-ASD group were 4 patients (14.8%), showing that preoperative disc degeneration was significantly more severe in the ASD group. Conclusion: Percutaneous pedicle screw fixation is favorable technique to prevent ASD for two levels fusion, however, when the patient is old or the preoperative disc degeneration of the adjacent segment is severe, there is the risk of postoperative ASD, and thus special attention should be paid during the follow-up period.

Degenerative Changes of Adjacent Segment after Anterior Cervical Discectomy and Fusion

Study Design: A retrospective radiologic analysis of 34 patients Objectives: To evaluate the factors influencing the radiographic degenerative changes in the adjacent segments in one-level ACDF (ed note: define ACDF). Summary of Literature Review: There is a 25% incidence of adjacent segment degeneration after 5 years. Materials and Method: From 2002 to 2005, 34 patients (male 23, female 11) underwent anterior cervical spine fusion using a cage or bone block for degenerative cervical spine. The mean age of the patients was 51 years and the mean follow-up period was 24 months. The degenerative findings of the upper and lower adjacent segment were measured from the pre-operative MRI. The fused segment curvature, disc heights of the adjacent segments, displacement of the vertebral bodies and angular mobility in the adjacent segments were measured from the pre-operative and final follow-up lateral views in the neutral position, in both flexion and extension. Results: Degenerative changes in the adjacent segments were observed in 19 of the 34 patients. The group with degenerative changes showed significantly more lordotic angular loss of the fusion segments (11.9±3.1�) at the follow-up observation than the group with no degenerative changes (9.0±1.1�) (p=0.04). The group with degenerative change showed a significantly larger increase in disc height of the fusion segments (2.8±0.2 mm) at the follow-up observation than the group with no degenerative changes (2.2±0.3 mm) (p=0.02).The group with a Grade IV or higher level of pre-operative disc degeneration showed more degenerative changes in the adjacent segments than those with Grade III or lower. Conclusions: It is important to preserve the lordotic angle of fused segments and avoid excessive increases in disc height. The recurrence of the neurological is not associated with the preoperative adjacent segmental degenerative changes in ACDF.