Adjacent Level Disc Research Articles

Dynamic Cervical Spinal Canal Stenosis: Identifying Imaging Risk Factors in Extended Positions.

A retrospective study at a single academic institution. This study aimed to identify imaging risk factors for stenosis in extended neck positions undetectable in preoperative neutral magnetic resonance imaging (MRI) and improving decompression strategies for cervical spine disorders. Cervical disorders are influenced by various dynamic factors, with spinal stenosis appearing during neck extension. Despite the diagnostic value of dynamic cervical MRI, standard practice often uses neutral-position MRI, potentially influencing surgical outcomes. This study analyzed 143 patients who underwent decompression surgery between 2012 and 2014, who had symptomatic cervical disorders and MRI evidence of spinal cord or nerve compression but had no history of cervical spine surgery. Patient demographics, disease type, Japanese Orthopedic Association score, and follow-up periods were recorded. Spinal surgeons conducted radiological evaluations to determine stenosis levels using computed tomography myelography or MRI in neutral and extended positions. Measurements such as dural tube and spinal cord diameters, cervical alignment, range of motion, and various angles and distances were also analyzed. The residual space available for the spinal cord (SAC) was also calculated. During extension, new stenosis frequently appeared caudal to the stenosis site in a neutral position, particularly at C5/C6 and C6/C7. A low SAC was identified as a significant risk factor for the development of new stenosis in both the upper and lower adjacent disc levels. Each 1-mm decrease in SAC resulted in an 8.9- and 2.7-fold increased risk of new stenosis development in the upper and lower adjacent disc levels, respectively. A practical SAC cutoff of 1.0 mm was established as the threshold for new stenosis development. The study identified SAC narrowing as the primary risk factor for new stenosis, with a clinically relevant cutoff of 1 mm. This study highlights the importance of local factors in stenosis development, advocating for further research to improve outcomes in patient with cervical spine disorders.

Lumbar lordosis and sacral slope do not differ in two types of postoperative lumbar disc re-herniation: a cross-sectional observational study

BackgroundTo identify the differences of lumbar lordosis (LL) and sacral slope (SS) angles between two types of postoperative lumbar disc re-herniation, including the recurrence of same level and adjacent segment herniation (ASH).MethodsWe searched the medical records of lumbar disc herniation (LDH) patients with re-herniation with complete imaging data (n = 58) from January 1, 2013 to December 30, 2020 in our hospital. After matching for age and sex, 58 patients with LDH without re-herniation from the same period operated by the same treatment group in our hospital were served as a control group. Re-herniation patients were divided into two groups, same-level recurrent lumbar disc herniation group (rLDHG) and adjacent segment herniation group with or without recurrence (ASHG). The preoperative, postoperative and one month after operation LL and SS were measured on standing radiographs and compared with the control group by using t-test, ANOVA, and rank-sum test. Next, we calculated the odds ratios (ORs) by unconditional logistic regression, progressively adjusted for other confounding factors.ResultsCompared with the control group, the postoperative LL and SS were significantly lower in LDH patients with re-herniation. However, there were no differences in LL and SS between ASHG and rLDHG at any stage. After progressive adjustment for confounding factors, no matter what stage is, LL and SS remained unassociated with the two types of re-herniation.ConclusionsLow postoperative LL and SS angles are associated with degeneration of the remaining disc. Low LL and SS may be independent risk factors for re-herniation but cannot determine type of recurrence (same or adjacent disc level).

Optimal selection of cage height in oblique lateral interbody fusion : A cage larger than the adjacent level disc height is too much?

Optimal selection of cage height in oblique lateral interbody fusion : A cage larger than the adjacent level disc height is too much?

Mid-term and Long-term Outcomes After Total Cervical Disk Arthroplasty Compared With Anterior Cervical Discectomy and Fusion: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

A meta-analysis of randomized controlled trials (RCTs). The aim of this study was to compare mid-term to long-term outcomes of cervical disk arthroplasty (CDA) with those of anterior cervical discectomy and fusion (ACDF) for the treatment of symptomatic cervical degenerative disk disease. After ACDF to treat symptomatic cervical degenerative disk disease, the loss of motion at the index level due to fusion may accelerate adjacent-level disk degeneration. CDA was developed to preserve motion and reduce the risk of adjacent segment degeneration. Early-term to mid-term clinical outcomes from RCTs suggest noninferiority of CDA compared with ACDF, but it remains unclear whether CDA yields better mid-term to long-term outcomes than ACDF. Two independent reviewers searched PubMed, Embase, and the Cochrane Library for RCTs with at least 60 months of follow-up. The risk ratio or standardized mean difference (and 95% CIs) were calculated for dichotomous or continuous variables, respectively. Eighteen reports of 14 RCTs published in 2014-2023 were included. The pooled analysis demonstrated that the CDA group had a significantly greater improvement in neurological success and Neck Disability Index than the ACDF group. The ACDF group exhibited a significantly better improvement in the Short Form-36 Health Survey Physical Component Summary than the CDA group. Radiographic adjacent segment degeneration was significantly lower in the CDA group at 60- and 84-month follow-ups; at 120-month follow-up, there was no significant difference between the 2 groups. Although the overall rate of secondary surgical procedures was significantly lower in the CDA group, we did not observe any significant difference at 60-month follow-up between the CDA and ACDF group and appreciated statistically significant lower rates of radiographic adjacent segment degeneration, and symptomatic adjacent-level disease requiring surgery at 84-month and 108- to 120-month follow-up. The rate of adverse events and the neck and arm pain scores in the CDA group were not significantly different from those of the ACDF group. In this meta-analysis of 14 RCTs with 5- to 10-year follow-up data, CDA resulted in significantly better neurological success and Neck Disability Index scores and lower rates of radiographic adjacent segment degeneration, secondary surgical procedures, and symptomatic adjacent-level disease requiring surgery than ACDF. ACDF resulted in improved Short Form-36 Health Survey Physical Component Summary scores. However, the CDA and ACDF groups did not exhibit significant differences in overall changes in neck and arm pain scores or rates of adverse events.

Cervical disc arthroplasty with the Baguera C prosthesis: clinical and radiological results of a 10-year follow-up study

PurposeWe evaluated the long-term safety, mobility and complications of cervical total disc arthroplasty with the Baguera®C prosthesis over 10 years.MethodsWe included 91 patients treated by arthroplasty for cervical degenerative disc disease. A total of 113 prostheses were implanted (50 one-level, 44 two-level and 19 hybrid constructs). They were assessed for complications, clinically, with NDI and SF-12 questionnaires and by independent radiologists for ROM, HO, disc height and adjacent level degeneration.ResultsNo spontaneous migration, loss of fixation, subsidence, vascular complication or dislocation were observed. The reoperation rate was 1%. About 82.7% of the patients were pain free. About 9.9% were taking occasional grade I painkillers. Motricity and sensitivity were preserved in 98.8% and 96.3%. The NDI showed an average functional disability of 17.58%, 26% lower than preoperatively. The SF-12 scores were close to normal health. The average ROM at the treated level was 7.4°. Motion was preserved in 86.6%. Lack of motion was observed in 13.4%. Grades II and III H0 were present in 53.7% and 31.7%, respectively, Grade IV was present in 13.4%. Motion was preserved in 100% of the grades 0–III. The preoperative adjacent level disc height of 4.3 mm remained stable during all the follow-ups at 4.4 mm and 4.2 mm, respectively, at 5 and 10 years.ConclusionsAfter 10 years, cervical arthroplasty with the Baguera®C prosthesis presents excellent safety and functional results and low complications. Motion was preserved in 86.6%, with a 7.4° ROM. Although common, HO did not hinder motion. Adjacent disc height preservation confirms some adjacent level degeneration protection.

Minimally Invasive Fixation in Osteoporotic Vertebral Fractures: A Review Article

here are several surgical strategies which have been proposed to treat the osteoporotic patient with vertebral fracture, ranging from vertebral body cement augmentation, percutaneous/mini-open short segment pedicle screw fixation, and cortical bone trajectory screw to kyphotic deformity correction surgery. Minimally invasive spine surgery has the potential benefits of faster recovery, reduced blood loss, less postoperative wound pain, lower infection risk, and shorter length of hospital stay. Novel surgical techniques such as percutaneous instrumentation fixation, cortical bone trajectory technique, screw cement augmentation, and vertebral body augmentation are developed. However, various complications have been reported, including pedicle fracture, instrumentation loosening, adjacent-level disc degeneration with herniation, and progressive junctional kyphosis. The purpose of this review was to outline various advancements in minimally invasive spinal surgery for patients with osteoporosis. Minimally invasive surgical techniques for fixation including percutaneous instrumentation, cortical bone trajectory technique, screw cement augmentation, and vertebral body augmentation have benefited patient with osteoporosis. Studies and discussions about short-segment pedicle screw fixation (one level above and below the fracture level) have shown that it provides enough stability for thoracolumbar burst fractures. There are also complications, including cement embolism, adjacent vertebral fracture, neuraxial anesthesia, and infection, which have been observed with the above technique. With the advancement of instrument and technique, the complication rate decreased in recent studies. Minimally invasive fixation still has many advantages for patients with osteoporosis. Many of these studies and strategies only have evidence from biomechanical and cadaveric studies and require further clinical trials to establish their clinical efficacy.

Subtle segmental angle changes of single-level lumbar fusions and adjacent-level biomechanics: cadaveric study of optically measured disc strain.

Changes to segmental lordosis at a single level may affect adjacent-level biomechanics and overall spinal alignment with an iatrogenic domino effect commonly seen in adult spinal deformity. This study investigated the effects of different segmental angles of single-level lumbar fixation on stability and principal strain across the surface of the adjacent-level disc. Seven human cadaveric L3-S1 specimens were instrumented at L4-5 and tested in 3 conditions: 1) neutral native angle ("neutral"), 2) increasing angle by 5° of lordosis ("lordosis"), and 3) decreasing angle by 5° of kyphosis ("kyphosis"). Pure moment loads (7.5 Nm) were applied in flexion, extension, lateral bending, and axial rotation, followed by 400 N of axial compression alone and together with pure moments. Range of motion (ROM), principal maximum strain (E1), and principal minimum strain (E2) across different surface subregions of the upper adjacent-level disc (L3-4) were optically assessed. Larger magnitudes of either E1 or E2 indicate larger tissue deformations and represent indirect measures of increased stress. At the superior adjacent level, a significant increase in ROM was observed in kyphosis and lordosis versus neutral in flexion (p ≤ 0.001) and extension (p ≤ 0.02). ROM was increased in lordosis versus neutral (p = 0.03) and kyphosis (p = 0.004) during compression. ROM increased in kyphosis versus neutral and lordosis (both p = 0.03) in compression plus extension. Lordosis resulted in increased E1 across the midposterior subregion of the disc (Q3) versus neutral during right lateral bending (p = 0.04); lordosis and kyphosis resulted in decreased E1 in Q3 versus neutral with compression (p ≤ 0.03). Lordosis decreased E1 in Q3 versus neutral during compression plus flexion (p = 0.01), whereas kyphosis increased E1 in all quartiles and increased E2 in the midanterior subregion versus lordosis in compression plus flexion (p ≤ 0.047). Kyphosis decreased E1 in Q3 (p = 0.02) and E2 in the anterior-most subregion of the disc (Q1) (p = 0.006) versus neutral, whereas lordosis decreased E1 in Q3 (p = 0.008) versus neutral in compression plus extension. Lumbar spine monosegmental fixation with 5° offset from the neutral individual segmental angle altered the motion and principal strain magnitudes at the upper adjacent disc, with induced kyphosis resulting in larger principal strains compared with lordosis. Segmental alignment of single-level fusion influences adjacent-segment biomechanics, and suboptimal alignment may play a role in the clinical development of adjacent-segment disease.

Comparison of the Biomechanical Effect of the FFX Device Compared With Other Lumbar Fusion Devices: A Finite Element Study.

Lumbar decompression can result in postsurgical instability and spondylolisthesis in patients with lumbar spinal stenosis (LSS). While pedicle screw (PS) constructs improve stability and support fusion, their use can lead to adjacent level degeneration due to rigidity and resultant overload of anatomical structures. The FFX device is a facet spacer designed to be a less invasive alternative for obtaining fusion compared with PS. The present study aimed to compare biomechanical performance of the FFX device to different lumbar spine procedures using the finite element (FE) method. Comparative biomechanical study by FE method. An FE model for the lumbar spine was developed and validated to assess vertebral displacement and stress variations in the facet joints and discs following surgery. Modeled scenarios included a healthy spine as a reference model, laminectomy (LAM), and prior to/following L4-L5 fusion for LAM + FFX and LAM + PS. LAM increased displacement compared with the healthy spine and both instrumented spine procedures. Facet joint stress at adjacent levels for LAM + PS was significantly higher than with LAM + FFX prior to fusion (+13.5% for L3-L4; +15.7% for L5-S1). Adjacent level disc stress at L5-S1 was 7.7% higher for LAM + PS vs LAM + FFX. Adjacent level facet joint and disc stresses for LAM + FFX were equivalent to LAM + PS once fusion occurred. Instrumented spine fixation prevents the risk of lumbar instability associated with LAM alone. Compared with PS, the FFX device is a less invasive alternative for the treatment of LSS, which potentially lowers the risk of adjacent segment degeneration prior to fusion that provides equivalent stability once fusion is achieved.

Clinical and radiological mid- to long-term investigation of anterior lumbar stand-alone fusion: Incidence of reoperation and adjacent segment degeneration

IntroductionAnterior stand-alone fusion (ASAF) devices have been developed in an attempt to reduce adjacent segment degenerative changes observed with posterior instrumented fusion techniques. Research questionThe purpose of this study was to assess mid- to long-term clinical and radiological results following ASAF at the lumbosacral junction with special emphasis on the assessment of adjacent level pathologies.Materials & Methods: Clinical outcome scores and radiological data were acquired within an ongoing single-center prospective cohort study. Progression of adjacent level degeneration was evaluated based on MRI scans according to the Pfirrmann and Weishaupt classification system by two independent radiologists. ResultsThe results from 37 patients (FU ​≥ ​5 years) demonstrated high satisfaction rates and significant improvements in VAS and ODI scores. N ​= ​8 patients (21.6%) had to undergo subsequent surgery at the cranially adjacent level. The incidence of adjacent level disc degeneration and adjacent facet joint degeneration was 24.3% and 35.1%, respectively. More pronounced degenerative changes of the adjacent level discs (p ​= ​0.005) and facet joints (p ​= ​0.042) prior to surgery and a lower segmental lordosis reconstruction at the lumbosacral junction (p ​= ​0.0084) were identified as potential risk factors for the development of subsequent adjacent level pathologies. Discussion & ConclusionThe study revealed satisfactory clinical results at a mid-to long-term FU of ≥5 years. The incidence of adjacent level degeneration was higher than initially expected. Patients with preexisting radiographic signs of degenerative adjacent level changes have a higher risk for subsequent deterioration necessitating reoperation at the adjacent segment at later stages. Furthermore, adequate intraoperative segmental lordosis reconstruction at the index segment is paramount as the present data reveal this to be a key protective factor for adjacent segment preservation.

Radiological Changes in Adjacent and Index Levels after Cervical Disc Arthroplasty.

PurposeThe purpose of this retrospective study was to evaluate radiological and clinical outcomes in patients undergoing cervical disc arthroplasty (CDA) for cervical degenerative disc disease. The results may assist in surgical decision-making and enable more effective and safer implementation of cervical arthroplasty.Materials and MethodsA total of 125 patients who were treated with CDA between 2006 and 2019 were assessed. Radiological measurements and clinical outcomes included the visual analogue scale (VAS), the Neck Disability Index (NDI), and the Japanese Orthopaedic Association (JOA) myelopathy score assessment preoperatively and at ≥2 years of follow-up.ResultsThe mean follow-up period was 38 months (range, 25–114 months). Radiographic data demonstrated mobility at both the index and adjacent levels, with no signs of hypermobility at an adjacent level. There was a non-significant loss of cervical global motion and range of motion (ROM) of the functional spinal unit at the operated level, as well as the upper and lower adjacent disc levels, compared to preoperative status. The cervical global and segmental angle significantly increased. Postoperative neck VAS, NDI, and JOA scores showed meaningful improvements after one- and two-level CDA. We experienced a 29.60% incidence of heterotrophic ossification and a 3.20% reoperation rate due to cervical instability, implant subsidence, or osteolysis.ConclusionCDA is an effective surgical technique for optimizing clinical outcomes and radiological results. In particular, the preservation of cervical ROM with an artificial prosthesis at adjacent and index levels and improvement in cervical global alignment could reduce revision rates due to adjacent segment degeneration.

Long-Term Outcomes Following Lumbar Nucleus Replacement.

Nucleus replacement devices are designed to replace the native pain-generating lumbar nucleus while preserving the annulus fibrosus, endplates, and natural motion. The DASCOR Disc Arthroplasty Device seemed to perform well clinically but was discontinued in 2009. While there are no commercially available NRDs today, the potential advantages of using such devices have prompted a renewed interest in further developing the technology and assessing long-term outcomes for the DASCOR device. A retrospective review of hospital records from a single institution was performed to identify all patients that underwent implantation of a DASCOR device between 2006 and 2009. Clinical outcome and imaging data were gathered to assess device performance of the DASCOR device over an extended period of time. Clinical data were assessed using a visual analog scale for back pain (VAS), Oswestry Disability Index (ODI) scores, and analgesic medication use score (ANS). Magnetic resonance images were systematically evaluated at the index and adjacent disc levels: disc height, Modic changes, Pfirrmann grade, and any implant-associated findings. Twenty-six patients received DASCOR implants. Follow-up data were available for 22 patients. The mean age at time of implantation was 34.9 years. Long-term data were available for 14 patients (mean, 11.5 years) with a mean improvement in VAS of 4.0 +/- 2.8 (P < 0.0001), ODI 33.4 +/- 18.4 (P < 0.0001), and ANS 0.5 (P = 0.07) compared to baseline values, while 46% developed radiological adjacent segment degeneration on MRI and 54% did not. In total, 6 patients underwent revision surgery at the index level and 3 underwent surgery at adjacent lumbar levels. While any conclusions should be interpreted with caution, there was a subgroup of patients that had excellent clinical and radiological outcomes. Additional studies on this device or other similar devices would add to our knowledge regarding ideal treatment of discogenic low back pain in younger patients. Treatment of discogenic low back pain. 4.

Device profile of the sapphire XTM anterior cervical plate system: overview of its safety and efficacy

ABSTRACT Introduction:The Sapphire X Anterior Cervical Plate System is a new medical device designed to provide stability after anterior discectomy and fusion procedures. It has unique benefits over many of the more established plates on the market. It is manufactured predominantly from titanium alloy and was first launched in late 2020. Areas covered:The structure and unique features of the Sapphire X are described. The indications for its use are discussed. The delivery system designed for the plate is reviewed in detail. Research outlining the shortcomings of current plate technologies and alternative technologies in this market space are reviewed. Expert Opinion:The evidence in this article demonstrates the risk of adjacent-level ossification development (ALOD) with current cervical plate designs. The industry is saturated with cervical plate technologies, yet there are very few plates small enough to avoid encroaching upon adjacent levels of disc space, particularly in the upper subaxial cervical segments and in patients with small vertebrae. This device review demonstrates the successful application of a cervical plate device that is small enough to avoid encroachment on the adjacent-level disc spaces while providing immediate stability after discectomy and fusion in the cervical spine.

Value of Using Interbody Fusion Technique in Recurrent Lumbar Disc Hernia Patients

Background: The aim of this study is to compare the clinical and functional outcomes of recurrent lumbar disc herniation (RLDH) revision surgery by either rediscectomy alone or rediscectomy with transforaminal lumbar interbody fusion (TLIF).Methods: This prospective study was performed between August 2018 and August 2019. Twenty patients were surgically treated for recurrent lumbar disc herniation at the Department of Spine Surgery, Zagazig University Hospitals, and Nasser Institute Hospital. Ten patients underwent rediscectomy (Group A) and the other ten patients underwent rediscectomy with TLIF (Group B) with exclusion to any other pathologies (multisegmental spinal canal stenosis, adjacent level disc herniation, spondylolisthesis, spinal instability, spinal deformities, and tumors).Results: Results showed no significant difference between the two groups on clinical outcomes, but there was a significant improvement in clinical outcomes in both groups postoperatively. Regarding time till return to work, There was a statistically significant difference between the two studied groups regarding the time till return to work with shorter time among the rediscectomy group than the rediscectomy with TLIF group (2.1±0.7versus3.4±0.8, p-value=0.002).Conclusion: We concluded that patients without signs of spinal instability and/or severe back pain who suffer from leg pain will benefit from rediscectomy surgery in first time recurrence of herniation with no further benefits from re-discectomy with TLIF over re-discectomy alone in short term follow up.

A Retrospective Analysis of Superior Facet Joint Violation Between Open and Minimally Invasive Transforaminal Lumbar Interbody Fusion and its Relation to Adjacent Segment Disease.

A retrospective study. The aim was to analyze the superior facet joint violation (SFV) between open transforaminal lumbar interbody fusion (open-TLIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and its effect on the superior and inferior adjacent segment disc height, segmental lordosis, lumbar lordosis, and facet joint degeneration. We compared SFV between open-TLIF and MIS-TLIF and its correlation with different factors as well as its effect on adjacent segment disease. We retrospectively studied data of patients undergoing single level TLIF surgery from January 2013 to February 2016 in single institutional hospital. Axial and coronal postoperative computed tomography scan images were used to analyze SFV. In secondary analysis patients were divided into nonfacet violation group (NSFVG) and facet violation group (SFVG) and compared the changes on the superior and inferior adjacent level disc height, segmental lordosis, lumbar lordosis, and facet joint degeneration. Mean SFV grade was significantly greater in MIS-TLIF compared with open-TLIF (odds ratio: 0.638, confidence interval: 0.431-0.944; P=0.025). There was more grade 2 (10.71% vs. 5.60%) and grade 3 (4.46% vs. 1.29%) SFV in MIS-TLIF. Patient with age below 60 and body mass index (BMI) >30 kg/m2 in MIS-TLIF were more prone to high-grade SFV compared with open-TLIF. Further, logistic regression showed patients with BMI ≥30 kg/m2 has 7.137 increased odds of high-grade SFV (95% confidence interval: 3.261-15.618; P=0.000) compared with patients with BMI <30 kg/m2. Compared with NSFVG, SFVG has more SFV (0.096±0.244 vs. 0.177±0.317; P=0.012) and less improvement in lumbar visual analog scale scores -0.65±0.073 versus -0.67±0.074 (P=0.006). MIS-TLIF has more high-grade SFV as well as overall mean SFV in comparison to open-TLIF with BMI >30 kg/m2 and location of pedicle screw as an independent risk factor for SFV and risk of adjacent segment disease increases with SFV. Level III.

Treatment of Patients with Scoliosis Using a Unique Anterior Scoliosis Correction Technique

Treatment for adolescent idiopathic scoliosis (AIS) is dependent upon multiple factors, including curve type and magnitude, curve progression, skeletal maturity, and clinical trunk deformity. While fusion is effective at achieving curve correction, it is associated with disadvantages including prominent implants beneath the skin, back muscle scarring and atrophy, decreased spine range of motion, and decreased functional spinal mobility. Additional concerns include the potential for longer term development of premature adjacent level disc and facet joint degeneration above and below the fusion. Due to these issues with spinal fusion, surgeons have explored alternative surgical approaches to correct spinal deformity and halt curve progression using either growth modulation or remodeling of the spine while preserving motion. This paper provides an overview of a non-fusion scoliosis correction technique called Anterior Scoliosis Correction (ASC).

Radiological risk factors for recurrent lumbar disc herniation after percutaneous transforaminal endoscopic discectomy: a retrospective matched case-control study

To investigate radiological risk factors for recurrent lumbar disc herniation (rLDH) after percutaneous transforaminal endoscopic discectomy (PTED). Patients who underwent PTED due to a single-level L4-L5 or L5-S1 disc herniation from January 2013 to May 2019 were enrolled in this study. A matched case-control design was carried out in a single institution. Cases were defined as those who developed rLDH, and controls were matched from those patients without rLDH according to corresponding clinical characteristics. The radiological parameters were compared between two groups. The radiological risk factors for rLDH after PTED were identified by univariate and multivariate logistic regression analysis. A total of 2186 patients who underwent PTED at L4-L5 or L5-S1 level were enrolled in this study. Sixty-eight patients were diagnosed with rLDH, and 136 patients were selected from the remaining 2118 nonrecurrent patients as matched controls. Univariate analysis demonstrated that herniation type (P = 0.009), surgical-level disc degeneration (P < 0.001), adjacent-level disc degeneration (P = 0.017), disc height index (DHI) (P = 0.003), and sagittal range of motion (sROM) (P < 0.001) were significantly related to rLDH. Multiple logistic regression analysis showed that low grade of surgical-level disc degeneration (P < 0.001), senior grade of adjacent-level disc degeneration (P < 0.001), a high DHI (P = 0.012), and a large sROM (P < 0.001) were the radiological independent risk factors. This study showed that low grade of surgical-level disc degeneration, senior grade of adjacent-level disc degeneration, a high DHI, and a large sROM were the radiological independent risk factors for rLDH after PTED.

Comparison of adverse events between cervical disc arthroplasty and anterior cervical discectomy and fusion: a 10-year follow-up

BACKGROUND CONTEXTCervical disc arthroplasty (CDA) has been advocated as an alternative to anterior cervical discectomy and fusion (ACDF) with the added potential to reduce the risk of adjacent level disc degeneration and segmental instability. However, the long-term adverse events of arthroplasty have yet to be fully reported. PURPOSETo investigate the 10-year follow-up adverse events rates between CDA and ACDF. STUDY DESIGN/SETTINGThe study was a randomized, prospective, multicenter Investigational Device Exemption (IDE) trial and its continued follow-up as a postapproval study (PAS). Single level surgeries were performed for cervical disc pathologies between May 2002 and October 2004. PATIENT SAMPLEn=463 patients. OUTCOME MEASURESAdverse events comparison of CDA and ACDF from self-reported and physiologic measures. METHODSAt each evaluation time point, subjects were queried for adverse events since their last visit; and all adverse events were documented, regardless of whether or not they appeared related to the surgery or device. Adverse events were recorded, categorized, and assessed for severity and relationship to the study device and/or surgical procedure. The 10-year cumulative rates for each type of adverse events were summarized using a life-table method for the time-to-event analysis. A log-rank test was used to compare the two treatment groups. RESULTSA total of 242 patients received CDA and 221 patients received ACDF. At 10-year follow-up, 54% (130/242) of CDA patients and 47% (104/221) of the ACDF subjects were evaluated. At up to 10-year follow-up, 231 patients in the CDA group (cumulative rate 98.4%) and 199 patients in the ACDF group (cumulative rate 98.7%) had at least one adverse event. Overall, the difference in the cumulative rate of all adverse events over 10 years was not statistically different (p=0.166). The cumulative rates of the following adverse events were not different between the two groups for cancer, cardiovascular, death, dysphonia/dysphagia, gastrointestinal, infection, urogenital, respiratory, implant displacement/loosening, implant malposition, neck and arm pain, neurological, other pain, spinal events, and intraoperative vascular injury. However, there were more adverse events in the CDA group resulting from trauma (p=.012) and more spinal events at the index level (p=.006). The ACDF group had significantly more nonunion events (p=.019), and nonunion outcome pending (p=.034), adjacent level spinal events (p=.033), and events that fell into the “other” category (p=.015). CONCLUSIONSThe cumulative rates of patients who had any adverse events were not different between the artificial cervical disc and the anterior cervical arthrodesis groups. In addition, the cumulative rates were not different between the two groups for the majority of categories as well.

Effect of Changes in Postoperative Intervertebral Space Height on Clinical and Radiological Outcomes After Cervical Disc Replacement

Narrowing of intervertebral space height (ISH) is an important pathological change in degenerative spinal disease, and ideal intraoperative distraction and postoperative intervertebral space maintenance is one of the most expectant goals pursued by spinal surgeons. The effect of postoperative ISH changing on the clinical and radiological outcomes after cervical disc replacement is not fully understood, however. In this study, the height variation and general trend of postoperative ISH in all patients were analyzed. The patients were divided into 3 groups based on the change of postoperative intervertebral space height (ISH)-group A (ISH <2 mm), group B (ISH 2-4 mm), and group C (ISH >4mm)-and the clinical and radiographic results compared among the 3 groups. A total of 120 consecutive patients with symptomatic cervical disc disease were included in this study. The results showed that the mean ISH increased significantly from 0.729 mm before surgery to 1.143 mm at 1 week, then gradually decreased to 1.032 mm at 3 months, 0.980 mm at 6 months, 0.760 mm at one year, and 0.750 mm at the final follow-up. The average postoperative Neck Disability Index (NDI) was 19.73 ± 0.81, 13.74 ± 4.94, 17.19 ± 4.22, respectively, in the 3 groups at 1 year after surgery and the average range of motion (ROM) was 5.44° ± 3.85° in group A, 9.34° ± 4.38° in group B, and 6.51° ± 4.38° in group C. The mean diameter of the intervertebral foramen was 6.54 ± 1.86 mm in group A, 9.63 ± 2.38 mm in group B, and 9.31 ± 1.68 mm in group C. Degeneration at the superiorly adjacent disc level was observed in 13.51% patients in group A, 9.37% in group B, and 21.05% in group C. Degeneration at the inferiorly adjacent level was radiographically identified in 21.62% in group A, 14.06% in group B, and 26.32% in group C. This study revealed that cervical disc replacement cannot maintain the intervertebral disc height obtained immediately after surgery. There is no obvious correlation between the change in intervertebral space height and clinical efficacy in the early postoperative stage. Nonetheless, the intervertebral disc height may affect the NDI index 1 year after surgery. If the postoperative intervertebral space height change can be maintained at 2-4 mm at 1 year, satisfactory ROM, intervertebral foramen diameter, and relatively low adjacent segment degeneration may be obtained after cervical disc replacement.

ASSESSMENT OF OUTCOMES OF PATIENTS UNDERGOING DISC PRESERVING FUNCTIONAL CERVICAL DISC SURGERY

The concept of accelerated degeneration of adjacent disc levels as a consequence of increased stress caused by inter body fusion of cervical spine is widely accepted. These phenomenon supports the hypothesis that reconstruction of an intervertebral disc after discectomy with functional disc prosthesis would offer benefit. Degeneration of an intervertebral disc involves progressive dehydration and fibrosis of the nucleus pulposus. These modifications induce loss of elasticity, loss of intervertebral height, formation of osseous spurs, cracking and bulging of the annulus fibrosus, and eventually, extrusion of nucleus tissue. Hence based on above findings the present study was planned for Assessment of Outcomes of Patients Undergoing Disc Preserving Functional Cervical Disc Surgery.&#x0D; The present study was planned in Department of Neurosurgery, SKMCH, Muzaffarpur, Bihar, India. Total 10 cases operated for cervical radiculopathy were enrolled in the present study. Diagnostic evaluation was performed by anterior posterior and lateral standard radiographs of the cervical spine and magnetic resonance imaging (MRI) evaluation of the cervical spine. All patients had follow up X-ray of the cervical spine anterior and posterior view with flexion and extension study, at 4 weeks and at subsequent follow up.&#x0D; The data generated from the present study concluded that the major symptoms experienced by the patients were neck and radicular pain. C6-7 cervical root level was affected in majority patients. Majority of the had an excellent surgical results. Post operative follow up X-ray after 6 months revealed adequate motion at the operated site.&#x0D; Keywords: Cervical Disc Surgery, Cervical radiculopathy, Disc preserving, Disc Herniation, etc.

Lumbar disc height and vertebral Hounsfield units: association with interbody cage subsidence.

Postoperative subsidence of transforaminal lumbar interbody fusion (TLIF) cages can result in loss of lordosis and foraminal height, and potential recurrence of nerve root impingement. The objectives of this study were to determine factors associated with TLIF cage subsidence. Specifically, the authors sought to determine if preoperative disc height compared to cage height could be used to predict TLIF interbody cage subsidence, and if decreased postoperative vertebral Hounsfield units (HUs) predisposed to cage subsidence. The authors retrospectively reviewed all patients undergoing instrumented TLIF from two institutions between July 2004 and June 2014. The preoperative disc height was measured for the operative and adjacent-level disc on MRI. The difference between cage and disc heights was measured and compared between the subsidence and nonsubsidence groups. The average HUs of the L1 vertebral body were measured on CT scans. Eighty-nine patients were identified with complete imaging and follow-up information. Forty-five patients (50.6%) had evidence of interbody cage subsidence on follow-up CT. The average cage subsidence was 5.5 mm (range 2.2-10.8 mm). The average implant height was significantly higher in the subsidence group compared to the nonsubsidence group (12.6 vs 11.2 mm). Additionally, the difference between cage height and preoperative adjacent-level disc height was also significantly larger in the subsidence group (3.8 vs 1.2 mm). First lumbar vertebral body (L1) HUs were significantly higher in the nonsubsidence versus the subsidence group (167.8 vs 137.71 HUs, p = 0.002). Multivariate logistic regression analysis identified suprajacent disc height and L1 HUs to be independent predictors of interbody cage subsidence. Receiver operating characteristic curves identified a suprajacent to cage height difference > 1.3 mm to have a 93.3% sensitivity for cage subsidence. This study is the first of its kind to demonstrate the association between vertebral body HUs and suprajacent disc height with the development of interbody cage subsidence after TLIF. The authors found that patients with lower HUs in the L1 vertebral body were more likely to experience subsidence, regardless of surgical level. Additionally, the study demonstrated that interbody cage height > 1.3 mm above the height of the suprajacent level is an independent risk factor for cage subsidence, with 93.3% sensitivity. These findings suggest that these factors may be utilized to create a template preoperatively for intraoperative cage selection.