Interspinous Process Research Articles

Early Outcome of Discectomy with Interspinous Process Distraction Device a Retrospective Cross-Sectional Study

Orthopedic Research Online Journal Early Outcome of Discectomy with Interspinous Process Distraction Device a Retrospective Cross-Sectional Study Gunaseelan Ponnusamy* Nasional Universty of Malaysia, Malaysia *Corresponding author: Gunaseelan Ponnusamy, Nasional Universty of Malaysia, 1938 Jalan G-1, Taman Melawati 53100 Kuala Lumpur, Malaysia Submission: February 25, 2017; Published: March 21, 2018 DOI: 10.31031/OPROJ.2018.02.000536 ISSN : 2576-8875Volume2 Issue3

Динамическая межостистая фиксация при спинальном поясничном стенозе: компромисс или вариант решения?

Introduction Currently, there is no single concept of interspinous process stabilization. Some authors consider the procedures to be a trade-off for the elderly population with vague morphological changes and neurogenic claudication whereas others do not support the practice, and still others offer it as an alternative to conservative and conventional surgical treatment for lumbar spinal stenosis (LSS). Material and methods The study included 22 patients with LSS. The patients were followed for 6 months. The clinical outcomes measures were neurological assessment, the Wong-Baker pain rating scale, Oswestry Disability Index (ODI). Radiographic evaluation and statistical analysis were also used. Surgical treatment included distraction laminoplasty and placement of interspinous dynamic fixator. Results Interspinous dynamic fixation and distraction laminoplasty resulted in regression of neurological deficiency and did not lead to deterioration of segmental and local imbalance. Clinical assessment of pain, radicular motor and sensory deficit and intermittent neurogenic claudication was performed. Morphological evaluation showed relative central spinal canal stenosis, foraminal stenosis and enduring degenerative spondylolisthesis (grades I and II). Conclusion Interspinous dynamic fixation is the method of choice for patients with lumbar spinal stenosis in presence of specific morphological and clinical manifestations.

Anterior and Lateral Lumbar Interbody Fusion With Supplemental Interspinous Process Fixation: Outcomes from a Multicenter, Prospective, Randomized, Controlled Study.

Rigid interspinous process fixation (ISPF) has received consideration as an efficient, minimally disruptive technique in supporting lumbar interbody fusion. However, despite advantageous intraoperative utility, limited evidence exists characterizing midterm to long-term clinical outcomes with ISPF. The objective of this multicenter study was to prospectively assess patients receiving single-level anterior (ALIF) or lateral (LLIF) lumbar interbody fusion with adjunctive ISPF. This was a prospective, randomized, multicenter (11 investigators), noninferiority trial. All patients received single-level ALIF or LLIF with supplemental ISPF (n = 66) or pedicle screw fixation (PSF; n = 37) for degenerative disc disease and/or spondylolisthesis (grade ≤2). The randomization patient ratio was 2:1, ISPF/PSF. Perioperative and follow-up outcomes were collected (6 weeks, 3 months, 6 months, and 12 months). For ISPF patients, mean posterior intraoperative outcomes were: blood loss, 70.9 mL; operating time, 52.2 minutes; incision length, 5.5 cm; and fluoroscopic imaging time, 10.4 seconds. Statistically significant improvement in patient Oswestry Disability Index scores were achieved by just 6 weeks after operation (P < .01) and improved out to 12 months for the ISPF cohort. Patient-reported 36-Item Short Form Health Survey and Zurich Claudication Questionnaire scores were also significantly improved from baseline to 12 months in the ISPF cohort (P < .01). A total of 92.7% of ISPF patients exhibited interspinous fusion at 12 months. One ISPF patient (1.5%) required a secondary surgical intervention of possible relation to the posterior instrumentation/procedure. ISPF can be achieved quickly, with minimal tissue disruption and complication. In supplementing ALIF and LLIF, ISPF supported significant improvement in early postoperative (≤12 months) patient-reported outcomes, while facilitating robust posterior fusion.

Long-term results with percutaneous interspinous process devices in the treatment of neurogenic intermittent claudication.

Neurogenic intermittent claudication (NIC) is the main symptom of degenerative lumbar spinal stenosis. Percutaneous interspinous process decompression devices (IPDs) have been designed as an alternative therapy to conservative treatment and to open decompressive surgery for patients suffering from NIC. Initial short-term results were encouraging. We present the long-term results of a group of patients that we followed to provide insight on long-term outcomes and effectiveness of this technique compared to other decompression methods. Fifteen patients operated for NIC by implantation of percutaneous IPDs have been prospectively monitored for reoperations or complications. Follow-up (FU) was interrupted if the patient was reoperated. Results were considered poor if the patient had to be reoperated at any stage of the FU or if the treatment failed to alleviate the pain after 6 months. Results were considered average if the patient still suffered some pain but did not require reoperation. The patients were followed up to 7 years after the initial surgery. The mean length of the FU was 3.53 years and all patients could be followed. At the end of the FU, the results were good in only 20.0% (3/15), average in 13.3% (2/15) and poor in 66.7% (10/15). Despite initial satisfactory results, long-term FU is disappointing, with 80% poor or average results. The long-term reoperation rate is high (66.6%), increases over time and is higher than after implantation of IPDs for decompression augmentation. Although this technique is simple and safe, its effectiveness seems short-lived. We recommend cautious use and informing patients about the risk of relatively early failure and recurrence.

Utilization of Interspinous Devices Throughout the United States Over a Recent Decade: An Analysis of the Nationwide Inpatient Sample.

Study Design:Retrospective database study.Objectives:Analysis of economic and demographic data concerning interspinous device (ID) placement throughout the United States to improve value-based care and health care utilization.Methods:The National Inpatient Sample (NIS) database was queried for patients who underwent insertion of an interspinous process spinal stabilization device (ICD-9-CM 84.80) between 2008 and 2014 across 44 states. Demographic and economic data were obtained which included the annual number of surgeries, age, sex, insurance type, location, and frequency of routine discharge. The NIS database represents a 20% sample of discharges from US hospitals, which is weighted to provide national estimates.Results:There was a 73% decrease in ID implanted from 2008 to 2014. The mean cost associated with insertion of the device increased 28% from $13 653 in 2008 to $17 515 in 2014. The mean length of stay (LOS) increased from 1.8 to 2.4 days. Patients aged 45 to 64 years increased from 14.1% to 34.3% while patients aged 65 to 84 years decreased from 74.4% to 60.6%. By region, 34% of ID placement occurred in the South followed by 19.7% that occured in the Northeast. When stratifying by median income for patient zip code, the procedure was performed more in cities designated as higher rather than lower income areas (74.2% and 19.5%, respectively).Conclusions:Throughout the United States, there was a progressive decline in the insertion of interspinous spacers by 73% over the study period. The total costs for the procedure increased by 28% while the aggregate national charges decreased by 55.6% between 2008 and 2014.

Five-year durability of stand-alone interspinous process decompression for lumbar spinal stenosis.

BackgroundLumbar spinal stenosis is the most common indication for spine surgery in older adults. Interspinous process decompression (IPD) using a stand-alone spacer that functions as an extension blocker offers a minimally invasive treatment option for intermittent neurogenic claudication associated with spinal stenosis.MethodsThis study evaluated the 5-year clinical outcomes for IPD (Superion®) from a randomized controlled US Food and Drug Administration (FDA) noninferiority trial. Outcomes included Zurich Claudication Questionnaire (ZCQ) symptom severity (ss), physical function (pf), and patient satisfaction (ps) subdomains, leg and back pain visual analog scale (VAS), and Oswestry Disability Index (ODI).ResultsAt 5 years, 84% of patients (74 of 88) demonstrated clinical success on at least two of three ZCQ domains. Individual ZCQ domain success rates were 75% (66 of 88), 81% (71 of 88), and 90% (79 of 88) for ZCQss, ZCQpf, and ZCQps, respectively. Leg and back pain success rates were 80% (68 of 85) and 65% (55 of 85), respectively, and the success rate for ODI was 65% (57 of 88). Percentage improvements over baseline were 42%, 39%, 75%, 66%, and 58% for ZCQss, ZCQpf, leg and back pain VAS, and ODI, respectively (all P<0.001). Within-group effect sizes were classified as very large for four of five clinical outcomes (ie, >1.0; all P<0.0001). Seventy-five percent of IPD patients were free from reoperation, revision, or supplemental fixation at their index level at 5 years.ConclusionAfter 5 years of follow-up, IPD with a stand-alone spacer provides sustained clinical benefit.

324 Lumbar Interbody Fusion Status does not Correlate with Patient Reported Outcomes

Abstract INTRODUCTION Circumferential lumbar arthrodesis leads to high fusion rates for degenerative lumbar spine. Interspinous posterior fixation pedicle screw fixation as an adjunct to interbody graft led to similar fusion rates and patient reported scores in prospective randomized multi-center study. Although commonly used as surrogates of each other it remains unclear whether the fusion scores correlate with patient reported outcomes. METHODS Data was collected as part of a prospective multi-center (11 investigators) study of 101 patients receiving single-level antero-lateral lumbar interbody fusion with supplemental interspinous process fixation (ISPF) or pedicle screw fixation (PSF) for the treatment of degenerative disc disease and/or spondylolisthesis. Subjects were randomized 2:1, ISPF to PSF, for posterior fixation. Patients were followed up to 24 months post-op. Patient reported outcome indices (ODI, SF-36) were collected at each follow-up time point. Lumbar x-ray radiographs were taken at 12 and 24 months. Interbody fusion was scored by an independent radiologist using the Brantigan-Stefee Fraser (BSF) criteria (BSF-1: pseudarthrosis; BSF-2: radiographic locked pseudarthrosis; BSF-3: radiographic fusion). A logistic regression model was used to determine whether a relationship existed between quality of fusion (BSF-3 vs. BSF-1&amp;2) and clinical index improvement at 12 and 24 months. RESULTS &gt;Change in ODI score at 12 and 24 months was not significantly associated with BSF score (P = 0.78 and P = 0.64, respectively). At 12 months,, BSF-3 patients had on average 1.4 greater reduction in ODI compared to BSF-1&amp;2 (95% CI: -8.61, 11.41). Changes in SF-36 score were not significantly associated with BSF score (P = 0.63 and P = 0.18, respectively). For SF-36 Mental, BSF-3 patients had a 2.21 greater increase compared to BSF-1&amp;2 (95% CI: -6.7, 11.13). Instead in SF-36 Physical, BSF-3 patients had a 4.14 lesser increase compared to BSF-1&amp;2 (95% CI: -10.15, 1.88) CONCLUSION Radiological lumbar interbody fusion grading using BSF scale do not correlate with patient reported outcome.

Long-term Clinical Outcomes and Quality of Life in Elderly Patients Treated with Interspinous Devices for Lumbar Spinal Stenosis.

Lumbar spinal stenosis (LSS) is a common degenerative condition that occurs in the spine with increasing age. Clinically, LSS causes a progressive reduction in walking autonomy, resulting in a poor quality of life and impaired functional capacity. The aim of this study was to evaluate the clinical outcome and quality of life of elderly patients presenting with LSS and associated comorbidities after a 5-year follow-up who were treated with an interspinous process device (IPD). Sixty patients > 75 years of age presenting with symptomatic degenerative LSS were included. All were treated with an IPD under local anesthesia. American Society of Anesthesiology score, Zurich Claudication Questionnaire, and Short Form 36 were evaluated pre- and postoperatively and at the follow-up visit each year for 5 years. The mean surgery time while under local anesthesia was 20 minutes. Forty-eight patients were followed for 5 years. Significant clinical improvements in all outcome scores (p < 0.05) both postoperatively or at follow-up were found. IPD seems to be an effective and safe treatment for LSS in elderly patients with general comorbidities. In our study, all followed up patients had a meaningful improvement of their quality of life even at 5 years after surgery.

Pivotal trials of orthopedic surgical devices in the United States: predominance of two-arm non-inferiority designs

BackgroundThe United States Food and Drug Administration (FDA) reviews class III orthopedic devices submitted for premarket approval with pivotal clinical trials. The purpose of this study was to determine the types of orthopedic devices reviewed, the design of their pivotal clinical trials, and the subjective factors affecting the interpretation of clinical trial data.MethodsMeetings of the FDA Orthopaedic and Rehabilitation Devices Panel were identified from 2000–2016. Meeting materials were collected from FDA electronic archives and notes were made regarding the device-type and subsequent approval and recall, the design of pivotal clinical trials, and issues of trial interpretation debated during panel deliberations.ResultsThe panel was convened on 29 separate occasions over the course of 35 days to deliberate 38 distinct topics. Of these, 23 topics included clinical data submitted for approval of a device, and two topics were excluded. Of the 23 devices, five were biologic, three were hip arthroplasty, three were disc arthroplasty, two were viscosupplementation, three were interspinous process devices, and seven were other devices. Of the 23 pivotal trials, 20 (87.0%) were randomized controlled trials (RCTs), consisting of 13 (65.0%) non-inferiority trials and 7 (35.0%) superiority trials, and all RCTs were two-arm trials. At panel, the most commonly debated issues were related to the design and interpretation of non-inferiority trials.ConclusionsA broad array of device types is reviewed by the FDA. The predominance of two-arm non-inferiority trials as pivotal studies indicates that the nuances of their design and interpretation are commercially important.

Transforaminal Lumbar Interbody Fusion with Rigid Interspinous Process Fixation: A Learning Curve Analysis of a Surgeon Team's First 74 Cases.

BackgroundStudies have shown that a significant learning curve may be associated with adopting minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) with bilateral pedicle screw fixation (BPSF). Accordingly, several hybrid TLIF techniques have been proposed as surrogates to the accepted BPSF technique, asserting that less/fewer fixation(s) or less disruptive fixation may decrease the learning curve while still maintaining the minimally disruptive benefits. TLIF with interspinous process fixation (ISPF) is one such surrogate procedure. However, despite perceived ease of adaptability given the favorable proximity of the spinous processes, no evidence exists demonstrating whether or not the technique may possess its own inherent learning curve. The purpose of this study was to determine whether an intraoperative learning curve for one- and two-level TLIF + ISPF may exist for a single lead surgeon.MethodsSeventy-four consecutive patients who received one- or two-Level TLIF with rigid ISPF by a single lead surgeon were retrospectively reviewed. It was the first TLIF + ISPF case series for the lead surgeon. Intraoperative blood loss (EBL), hospitalization length-of-stay (LOS), fluoroscopy time, and postoperative complications were collected. EBL, LOS, and fluoroscopy time were modeled as a function of case number using multiple linear regression methods. A change point was included in each model to allow the trajectory of the outcomes to change during the duration of the case series. These change points were determined using profile likelihood methods. Models were fit using the maximum likelihood estimates for the change points. Age, sex, body mass index (BMI), and the number of treated levels were included as covariates.ResultsEBL, LOS, and fluoroscopy time did not significantly differ by age, sex, or BMI (p ≥ 0.12). Only EBL differed significantly by the number of levels (p = 0.026). The case number was not a significant predictor of EBL, LOS, or fluoroscopy time (p ≥ 0.21). At the time of data collection (mean time from surgery: 13.3 months), six patients had undergone revision due to interbody migration. No ISPF device complications were observed.ConclusionsStudy outcomes support the ideal that TLIF + ISPF can be a readily adopted procedure without a significant intraoperative learning curve. However, the authors emphasize that further assessment of long-term healing outcomes is essential in fully characterizing both the efficacy and the indication learning curve for the TLIF + ISPF technique.

Superion Interspinous Spacer Treatment of Moderate Spinal Stenosis: 4-Year Results.

To determine 4-year clinical outcomes in patients with moderate lumbar spinal stenosis treated with minimally invasive stand-alone interspinous process decompression using the Superion device. The 4-year Superion data were extracted from a randomized, controlled Food and Drug Administration investigational device exemption trial. Patients with intermittent neurogenic claudication relieved with back flexion who failed at least 6 months of nonsurgical management were enrolled. Outcomes included Zurich Claudication Questionnaire (ZCQ) symptom severity (ss), physical function (pf) and patient satisfaction (ps) subdomains, leg and back pain visual analog scale (VAS), and Oswestry Disability Index (ODI). At 4-year follow-up, 89 of the 122 patients (73%) provided complete clinical outcome evaluations. At 4 years after index procedure, 75 of 89 patients with Superion (84.3%) demonstrated clinical success on at least 2 of 3 ZCQ domains. Individual component responder rates were 83% (74/89), 79% (70/89), and 87% (77/89) for ZCQss, ZCQpf, and ZCQps; 78% (67/86) and 66% (57/86) for leg and back pain VAS; and 62% (55/89) for ODI. Patients with Superion also demonstrated percentage improvements over baseline of 41%, 40%, 73%, 69%, and 61% for ZCQss, ZCQpf, leg pain VAS, back pain VAS, and ODI. Within-group effect sizes all were classified as very large (>1.0): 1.49, 1.65, 1.42, 1.12, and 1.46 for ZCQss, ZCQpf, leg pain VAS, back pain VAS, and ODI. Minimally invasive implantation of the Superion device provides long-term, durable relief of symptoms of intermittent neurogenic claudication for patients with moderate lumbar spinal stenosis.

Biomechanical effect of interspinous process distraction height after lumbar fixation surgery: An in vitro model.

Pedicle screw fixation may induce abnormal activity at adjacent segment and accelerate the degeneration of lumbar vertebrae. Dynamic stabilizers could provide an intermediate solution between conservative treatment and fusion surgery. Lumbar vertebral segment cephalad to instrumented fixation was the most common localization of adjacent segment degeneration. The aim of this study is to explore the use of interspinous process devices in the lumbar vertebral segment cephalad to fixation segment in changing the mechanical distribution and limiting abnormal activity of the spine. Eight specimens were tested in the following groups: intact group, instability group (bilateral facetectomy at L3-L4), fixation group (bilateral facetectomy and pedicle screw fixation at L3-L4), and hybrid fixation group (fixation at L3-L4 and simulating interspinous device implantation of 6, 8, 10, 12, 14, 16, and 18 mm at L2-L3). Range of motion, motion of vertebral body, and strain distribution change were recorded. The range of motion in extension with 16- and 18-mm hybrid constructs was significantly lower than intact, instability, and fixation groups. In flexion and lateral bending, the strain values of L4 inferior articular process with 18-mm hybrid construct have a significant difference compared with other groups. In axial rotation, under the condition of a contralateral state, the strain values of L2 superior articular process with 18-mm hybrid construct have a significant difference compared with intact and fixation groups. The strain value of the L4 inferior articular process had negative correlation with height distraction in three dimensions, except extension. A negative correlation between the strain value of the L2 superior articular process and distraction height was found in contralateral bending and contralateral axial rotation. Interspinous process devices above the fixation segment can change the mechanical distribution of the spine and limit activity in some of the segments of the spine, which may delay the degeneration of the adjacent segment.

Future Advances in Spine Surgery: The AOSpine North America Perspective.

This focus issue highlights state-of-the-art techniques, equipment, and practices in the modern era of spine surgery while providing a glimpse into the next generation of patient care. A broad range of topics are presented to cover the full spectrum of the field. Degenerative diseases are discussed in a series of 3 articles on (1) pathophysiology, management, and surgical approaches to degenerative cervical myelopathy; (2) novel approaches to degenerative thoracolumbar disease (eg, interspinous process spacers, minimally invasive/endoscopic approaches); and (3) animal models and emerging therapeutics in degenerative disk disease. Also included is a unique study aiming to establish the critically important cost-benefit relationship for spine procedures with perspectives on how value is defined and how to address variability.Primary and metastatic spine oncology are reviewed with a focus on upcoming targeted biologics, subspecialized radiotherapy (eg, proton-beam, carbon-ion, stereotactic radiosurgery), genetic profiling to stratify risk, and morbidity-reducing surgical approaches (eg, minimally invasive/endoscopic resections, percutaneous instrumentation). Trauma is discussed in 2 high-quality papers on controversies in spinal trauma and neuroprotective/neuroregenerative interventions for traumatic spinal cord injury. A stimulating article on cervical, thoracolumbar, and pediatric deformity highlights the rapid evolution of deformity surgery with a look at innovative tools (eg, high-fidelity 3-dimensional reconstructions, magnetically controlled growing rods) and their impact on quality of life. Additionally, a must-read article on surgical site infections discusses key risk factors and evidence-based preventative techniques to remain aware of. Finally, cutting-edge technologies, including computer-assisted navigation, shared-control robotics, neuromodulation, novel osteobiologics, and biomaterials, are covered in detail in a series of 3 fascinating papers on the next generation of the field.Each section intends to highlight the salient literature and afford insights from multiple key thought leaders in an effort to minimize bias and provide varied perspectives. Overall, we hope this issue provides high-quality, evidence-based data relevant to trainees and practicing surgeons while also stimulating excitement about the future of spine surgery.

An automated CT-based method to quantify the 3D anatomy of the posterior elements of the human thoracic and lumbar spine

This study presents the development and implementation of a highly automated computed tomography-based method to quantify 3D posterior element anatomy. The use of the posterior elements as the site of the bone–implant interface in spinal posterior fusion plating requires quantitative morphologic human data on these structures. Human thoracic and lumbar vertebrae (n = 307) were automatically segmented to isolate the spinous processes and laminae using atlas-based deformable registration. Analysis was conducted to determine lateral facing surface area, transverse and coronal plane angulation, and interspinous process distance between adjacent levels. The considered metrics demonstrated division based on spinal level (T12–L5 vs. T1–T11), with larger measured outcomes for males. This anatomic study provides an automated method for acquiring 3D morphological information that can be used to guide posterior element device design.

Percutaneous transforaminal endoscopic discectomy combined with Coflex interspinous process dynamic reconstruction system in treatment of youth lumbar disc herniation

To evaluate the effectiveness of percutaneous transforaminal endoscopic discectomy (PTED) combined with Coflex interspinous process dynamic reconstruction system for the treatment of youth lumbar disc herniation (LDH). The clinical data of 52 patients with LDH treated by PTED combined with Coflex were retrospectively analyzed between February 2013 and March 2015. The involved segments were L 4, 5 in 30 cases and L 5, S 1 in 22 cases. In 30 patients at L 4, 5 level, there were 18 males and 12 females with an average age of 25 years (range, 18-34 years) and a mean disease duration of 10 months (range, 6-16 months). In 22 patients at L 5, S 1 level, there were 10 males and 12 females with an average age of 25.5 years (range, 19-32 years) and a mean disease duration of 12 months (range, 6-18 months). The operation time and intraoperative blood loss were recorded. Oswestry disability index (ODI) and Japanese Orthpoaedic Association (JOA) score were used for effectiveness assessment. Radiograpic indexes were calculated on X-ray films before operation and final follow-up, including ventral intervertebral space height (VH), dorsal intervertebral space height (DH), intervertebral foramen height (IFH), the range of motion (ROM) of involved segment, and the ROM of upper adjacent segment. The operations were successfully completed in 52 patients. The operation time and intraoperative blood loss were (89.7±16.5) minutes and (42.7±11.3) mL in patients at L 4, 5 level, and were (94.6±18.2) minutes and (47.6±13.4) mL in patients at L 5, S 1 level. Incisions healed by first intention. All patients were followed up 12-18 months (mean,16 months) in patients at L 4, 5 level and 12-20 months (mean, 17 months) in patients at L 5, S 1 level. At final follow-up, ODI, and JOA score were significantly improved when compared with preoperative ones in all patients ( P<0.05). X-ray films showed no complication of Coflex loosening, spinous process fracture, or articular process fracture occurred. At final follow-up, VH, DH, and IFH were significantly improved when compared with preoperative ones in all patients ( P<0.05), and the ROM of involved segment was significantly reduced compared with preoperative one ( P<0.05), but the ROM of upper adjacent segment showed no significant difference when compared with preoperative one ( P>0.05). PTED combined with Coflex is a safe and effective minimally invasive surgery in treating youth LDH; however, it still needs further clinical studies.

Surgical treatment of bilateral nondisplaced isthmic lysis by interlaminar fixation device.

Study Design:Spondylolysis is a defect in the portion of pars interarticularis. The latter affects approximately 6% of the population. It is caused by repetitive trauma in hyperextension. Low back pain is the most common symptom.Methods:We implanted interspinous process devices in 12 patients with isthmic lysis without spondylolisthesis for low back pain. The purpose of the surgery was to conduct a minimally invasive procedure.Results:In eight cases, patients became asymptomatic. In two cases, there has been a considerable improvement. In two cases, no change had been noted.Conclusion:This good result motivates us to consider this approach a part of therapeutic arsenal for some cases of spondylolysis.

Could the Topping-Off Technique Be the Preventive Strategy against Adjacent Segment Disease after Pedicle Screw-Based Fusion in Lumbar Degenerative Diseases? A Systematic Review.

The “topping-off” technique is a new concept applying dynamic or less rigid fixation such as hybrid stabilization device (HSD) or interspinous process device (IPD) for the purpose of avoiding adjacent segment disease (ASD) proximal to the fusion construct. A systematic review of the literature was performed on the effect of topping-off techniques to prevent or decrease the occurrence of ASD after lumbar fusion surgery. We searched through major online databases, PubMed and MEDLINE, using key words related to “topping-off” technique. We reviewed the surgical results of “topping-off” techniques with either HSD or IPD, including the incidence of ASD at two proximal adjacent levels (index and supra-adjacent level) as compared to the fusion alone group. The results showed that the fusion alone group had statistically higher incidence of radiographic (52.6%) and symptomatic (11.6%) ASD at the index level as well as higher incidence (8.1%) of revision surgery. Besides, the HSD (10.5%) and fusion groups (24.7%) had statistically higher incidences of radiographic ASD at supra-adjacent level than the IPD (1%). The findings suggest that the “topping-off” technique may potentially decrease the occurrence of ASD at the proximal motion segments. However, higher quality prospective randomized trials are required prior to wide clinical application.

Surgical options for lumbar spinal stenosis.

Surgical options for lumbar spinal stenosis.

Application of the Coflex Interlaminar Stabilization in Patients With L5/S1 Degenerative Diseases: Minimum 4-Year Follow-up

The Coflex is one of the representatives of posterior dynamic interspinous process device, but no study with the application of Coflex interlaminar stabilization in L5/S1 level has been performed. The aim of this study was to evaluate the feasibility and validity of the Coflex interlaminar stabilization in the treatment of degenerative lumbar diseases on L5/S1 level. A retrospective study was conducted for a consecutive series of 33 patients with degenerative lumbar spinal stenosis or lumbar disc herniation located in L5/S1 between November 2007 and September 2010. Subjects were all received decompressive laminectomy with implantation of Coflex device. Clinical effects were evaluated by visual analog scale and Oswestry Disability Index. Radiographs were done preoperatively, postoperatively, and at final follow-up. The Coflex devices were successfully implanted in all subjects. Fourteen cases completed the operations by inverting the prosthesis on account of too short S1 spinous processes. During the minimum 4-year follow-up period, all patients had obvious improvement in clinical effects (P < 0.05). Radiological evaluation revealed that dorsal intervertebral space height and intervertebral foramen height of target level increased significantly in all cases postoperatively and maintained well to final follow-up. In addition, the sagittal range of motion of operated level was restricted (P < 0.05), and the range of motion of adjacent segment did not change much (P > 0.05). The Coflex is an efficacious dynamic interspinous process device for the treatment of degenerative lumbar diseases that can apply to L5/S1.

Baastrup Disease/Interspinous Bursitis

Baastrup disease (BD), an uncommon back pain syndrome, is characterized by pathologic approximation of adjacent spinous processes on a sagittal plane image. BD occurs most commonly at the lumbar L4-L5 level and tends to be more common in the elderly. The etiology is not precisely known, but BD may develop secondary to chronic active inflammatory facet arthropathy, leading to interspinous osteophytes and approximation of the adjacent spinous processes. Clinically, BD should be considered in the differential diagnosis of back pain if there is (1) midline back pain reproduced with palpation of the spinous process and exacerbated by extension of the lumbar spine and (2) direct contact of adjacent spinous processes on the lateral view of a plain x-ray image. Magnetic resonance imaging is more sensitive in detecting interspinous inflammation and the formation of bursa and new bone. Major differential diagnoses of BD include proliferative hyperostosis of the lumbar spinous processes, degenerative disease of the spine, sclerotic bone metastases to the spine, and ankylosing spondylosis. BD can be managed initially with nonsteroidal antiinflammatory drugs, a short-term steroid dose pack, and physical therapy. Injection of a local anesthetic to the inflamed spinous process and associated interspinous ligaments may be diagnostic, and injection of a local anesthetic/corticosteroid combination may be therapeutic. Surgery is reserved for patients with refractory BD. Surgical options include interspinous process decompression devices and excision of the affected spinous processes.