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1.  Miniopen Oblique Lateral L5-S1 Interbody Fusion: A Report of 2 Cases 
Case Reports in Orthopedics  2014;2014:603531.
Extreme lateral interbody fusion (XLIF) has been widely used for minimally invasive anterior lumbar interbody fusion (ALIF), but an approach to L5-S1 is difficult because of the iliac crest. In the current study, we present 2 cases using minimally invasive oblique lateral interbody fusion (OLIF) of L5-S1. The patients showed foraminal stenosis between L5 and S1 and severe low back and leg pain. The patients were placed in a lateral decubitus position and underwent OLIF surgery (using a cage and bone graft from the iliac crest) without posterior decompression. Posterior screws were used in the patients. Pain scores significantly improved after surgery. There was no spinal nerve, major vessel, peritoneal, or urinary injury. OLIF surgery was minimally invasive and produced good surgical results without complications.
PMCID: PMC4221972  PMID: 25400963
2.  The importance of the anterior longitudinal ligament in lumbar disc arthroplasty: 36-Month follow-up experience in extreme lateral total disc replacement 
Current total disc replacement (TDR) for lumbar spine requires an anterior approach for implantation but presents inherent limitations, including risks to the abdominal structures, as well as resection of the anterior longitudinal ligament. By approaching the spine laterally, it is possible to preserve the stabilizing ligaments, which are a natural restraint to excessive rotations and translations, and thereby help to minimize facet stresses. This less invasive approach also offers a biomechanical advantage of placement of the device over the ring apophysis bilaterally; importantly, it also offers a greater opportunity for safer revision surgery, if necessary, by avoiding scarring of the anterior vasculature. We present the clinical and radiologic results of a lateral TDR device from a prospective single-center study.
A new metal-on-metal TDR device designed for implantation through a true lateral, retroperitoneal, transpsoatic approach (extreme lateral interbody fusion) was implanted in 36 patients with discography-confirmed 1- or 2-level degenerative disc disease. Clinical (pain and function) and radiographic (range of motion) outcome assessments were prospectively collected preoperatively, postoperatively, and serially up to a minimum of 36 months’ follow-up.
Between December 2005 and December 2006, 36 surgeries were performed in 16 men and 20 women (mean age, 42.6 years). These included 15 single-level TDR procedures at L3-4 or L4-5, 3 2-level TDR procedures spanning L3-4 and L4-5, and 18 hybrid procedures (anterior lumbar interbody fusion) at L5-S1 and TDR at L4-5 (17) or L3-4 (1). Operative time averaged 130 minutes, with mean blood loss of 60 mL and no intraoperative complications. Postoperative X-rays showed good device placement, with restoration of disc height, foraminal volume, and sagittal balance. All patients were up and walking within 12 hours of surgery, and all but 9 were discharged the next day (7 of those 9 were hybrid TDR–anterior lumbar interbody fusion cases). Postoperatively, 5 of 36 patients (13.8%) had psoas weakness and 3 of 36 (8.3%) had anterior thigh numbness, with both symptoms resolving within 2 weeks. Of the 36 patients, 4 (11%) had postoperative facet joint pain, all in hybrid cases. Visual analog scale pain scores and Oswestry Disability Index scores improved by 74.5% and 69.2%, respectively, from preoperatively to 3-year follow-up. Range of motion at 3 years postoperatively averaged 8.1°. Signals of heterotopic ossification were present in 5 patients (13.9%), and 2 patients (5.5%) were considered to have fusion after 36 months.
The clinical and radiographic results of a laterally placed TDR have shown maintenance of pain relief and functional improvement over a long-term follow-up period. The benefits of the lateral access—minimal morbidity, avoidance of mobilization of the great vessels, preservation of the anterior longitudinal ligament, biomechanically stable orientation, and broader revision options—promote a new option for motion-preservation procedures.
PMCID: PMC4300872
Arthroplasty; Total disc replacement; XLIF; Minimally invasive; Lateral approach
3.  Endoscopic transforaminal decompression, interbody fusion, and percutaneous pedicle screw implantation of the lumbar spine: A case series report 
On the basis of the experiences gained from conventional open spinal procedures, a long list of desirable objectives have emerged with the evolution of the lesser invasive spinal procedures. At the top of that list is the desire to minimize the trauma of surgery. The rest of the objectives, which include reductions of operating time, surgical blood loss, hospital stay, postoperative narcotic medication, convalescence, complication rates, and escalating health care costs, as well as the desire of elderly patients to continue rigorous physical activities, largely depend on the ability to minimize the trauma of surgery. The purpose of this study was to investigate the feasibility of the least invasive lumbar decompression, interbody fusion and percutaneous pedicle screw implantation, to minimize surgical trauma without compromising the quality of the treatment outcome, as well as to minimize risk of complications.
In this case series, 60 patients with diagnoses of degenerative disc disease, degenerative motion segments with stenosis, and spondylolisthesis, in whom nonoperative treatments failed, were treated with endoscopic transforaminal decompression and interbody fusion by 1 surgeon in 2 centers. The outcome measures were as follows: operating time, intraoperative blood loss, hospital stay, Visual Analogue Scale (VAS) scores for back and leg pain, scores on the Roland-Morris Disability Questionnaire, and postoperative imaging studies. A consecutive series of patients who met the treatment criteria completed VAS forms and Roland-Morris questionnaires preoperatively. Surgical procedures included arthroscopic decompression of the foramina and the discs; endplate preparation and implantation of allograft bone chips and bone morphogenetic protein 2 on absorbable collagen sponge into the disc space; and percutaneous implantation of pedicle screws. Postoperatively, the patients again completed the VAS forms and Roland-Morris questionnaires. Their charts were reviewed for office notes, operative notes, hospital stay, medications, and imaging studies. The latest X-ray and computed tomography scan films were reviewed and analyzed. Patients were followed up for a minimum of 6 months. The literature was reviewed for comparison of outcomes.
Sixty patients met the inclusion criteria. The mean age was 52.8 years. The duration of illness averaged 5 years. Follow-up ranged from 6 to 25 months, with a mean of 12 months. Preoperative diagnoses included degenerative disc disease, degenerative motion segments with stenosis, and spondylolisthesis. The mean time in the operating room was 2 hours 54 minutes. Estimated blood loss averaged 57.6 mL. The duration of the hospital stay averaged 2.6 days. Preoperative back pain and leg pain were significantly reduced (P < .005). Forty-seven imaging studies obtained at the last visit, including X-ray and computed tomography scans, showed solid fusion in 28 patients (59.6%), stable fixation in 17 (36.2%), and osteolysis around the pedicle screws in 2 (4.2%). All patients had improvement of motor function, whereas 2 patients complained of residual numbness. In addition, 8 patients (13%) complained of residual discomfort on extension of the lumbar spine. Two patients had pedicle screw–related complications requiring surgery. A review of the literature showed that endoscopic transforaminal decompression and interbody fusion performed better than open transforaminal lumbar interbody fusion/posterior lumbar interbody fusion, minimally invasive transforaminal lumbar interbody fusion, and extreme lateral lumbar interbody fusion, with regard to most parameters studied.
The endoscopic transforaminal lumbar decompression, interbody fusion, and percutaneous pedicle screw instrumentation consistently produced satisfactory results in all demographics. It performed better than the alternative procedures for most parameters studied.
PMCID: PMC4300894
ETDIF; Arthroscopic; Posterolateral; Interbody; Percutaneous; BMP-2
4.  Mini-Open Approach for Direct Lateral Lumbar Interbody Fusion 
Asian Spine Journal  2014;8(4):491-497.
Study Design
Retrospective analysis.
To introduce the mini-open lateral approach for the anterior lumbar interbody fusion (ALIF), and to investigate the advantages, technical pitfalls and complications by providing basic knowledge on extreme lateral interbody fusion (XLIF) or direct lumbar interbody fusion (DLIF).
Overview of Literature
Recently, minimally invasive lateral approach for the lumbar spine is revived and receiving popularity under the name of XLIF or DLIF by modification of mini-open method when using the sequential tubular dilator and special expandable retractor system.
Seventy-four patients who underwent surgery by the mini-open lateral approach from September 2000 to April 2008 with various disease entities were included. Blood losses, operation times, incision sizes, postoperative time to mobilization, length of hospital stays, technical problems and complications were all analyzed.
The blood losses and operation times of patients who underwent simple ALIF were 61.2 mL and 86 minutes for one level, 107 mL and 106 minutes for two levels, 250 mL and 142.8 minutes for three levels, and 400 mL and 190 minutes for four levels of fusion. The incision sizes were on average 4.5 cm for one level, 6.3 cm for two levels, 8.5 cm for three levels and 10.0 cm for four levels of fusion. The complications were retroperitoneal hematoma (2 cases), pneumonia (1 case) and transient lumbosacral plexus palsy (3 cases).
Trials of mini-open lateral approach would be helpful before the trial of XLIF or DLIF. However, special attention is required for complications such as transient lumbosacral plexus palsy.
PMCID: PMC4149993  PMID: 25187867
Lumbar spine; Mini-open lateral approach; Interbody fusion
5.  Transforaminal lumbar interbody fusion: a safe technique with satisfactory three to five year results 
European Spine Journal  2005;14(6):551-558.
The unilateral transforaminal approach for lumbar interbody fusion as an alternative to the anterior (ALIF) and traditional posterior lumbar interbody fusion (PLIF) combined with pedicle screw instrumentation is gaining in popularity. At present, a prospective study using a standardized tool for outcome measurement after the transforaminal lumber interbody fusion (TLIF) with a follow-up of at least 3 years is not available in the current literature, although there have been reports on specific complications and cost efficiency. Therefore, a study of TLIF was undertaken. Fifty-two consecutive patients with a minimum follow-up of 3 years were included, with the mean follow-up being 46 months (36–64). The indications were 22 isthmic spondylolistheses and 30 degenerative disorders of the lumbar spine. Thirty-nine cases were one-level, 11 cases were two-level, and two cases were three-level fusions. The pain and disability status was prospectively evaluated by the Oswestry disability index (ODI) and a visual analog scale (VAS). The status of bony fusion was evaluated by an independent radiologist using anterior–posterior and lateral radiographs. The operation time averaged 173 min for one-level and 238 min for multiple-level fusions. Average blood loss was 485 ml for one-level and 560 ml for multiple-level fusions. There were four serious complications registered: a deep infection, a persistent radiculopathy, a symptomatic contralateral disc herniation and a pseudarthrosis with loosening of the implants. Overall, the pain relief in the VAS and the reduction of the ODI was significant (P<0.05) at follow-up. The fusion rate was 89%. At the latest follow-up, significant differences of the ODI were neither found between isthmic spondylolistheses and degenerative diseases, nor between one- and multiple-level fusions. In conclusion, the TLIF technique has comparable results to other interbody fusions, such as the PLIF and ALIF techniques. The potential advantages of the TLIF technique include avoidance of the anterior approach and reduction of the approach related posterior trauma to the spinal canal.
PMCID: PMC3489237  PMID: 15672243
Transforaminal lumbar interbody fusion (TLIF); Low back pain; Spinal fusion; Lumbar fusion; Interbody fusion
6.  Posterior lumbar interbody fusion using one diagonal fusion cage with transpedicular screw/rod fixation 
European Spine Journal  2003;12(2):173-177.
Posterior lumbar interbody fusion (PLIF) using threaded cages has gained wide popularity for lumbosacral spinal disease. Our biomechanical tests showed that PLIF using a single diagonal cage with unilateral facetectomy does add a little to spinal stability and provides equal or even higher postoperative stability than PLIF using two posterior cages with bilateral facetectomy. Studies also demonstrated that cages placed using a posterior approach did not cause the same increase in spinal stiffness seen with pedicle screw instrumentation, and we concluded that cages should not be used posteriorly without other forms of fixation. On the other hand, placement of two cages using a posterior approach does have the disadvantage of risk to the bilateral nerve roots. We therefore performed a prospective study to determine whether PLIF can be accomplished by utilizing a single diagonal fusion cage with the application of supplemental transpedicular screw/rod instrumentation. Twenty-seven patients underwent a PLIF using one single fusion cage (BAK, Sulzer Spine-Tech, Minneapolis, MN, USA) inserted posterolaterally and oriented anteromedially on the symptomatic side with unilateral facetectomy and at the same level supplemental fixation with a transpedicular screw/rod system. The internal fixation systems included 12 SOCON spinal systems (Aesculap AG, Germany) and 15 TSRH spinal systems (Medtronic Sofamor Danek, USA). The inclusion criteria were grade 1 to 2 lumbar isthmic spondylolisthesis, lumbar degenerative spondylolisthesis, and recurrent lumbar disc herniations with instability. Patients had at least 1 year of low back pain and/or unilateral sciatica and a severely restricted functional ability in individuals aged 28–55 years. Patients with more than grade 2 spondylolisthesis or adjacent-level degeneration were excluded from the study. Patients were clinically assessed prior to surgery by an independent assessor; they were then reassessed at 1, 3, 6, 12, 18, and 24 months postoperatively by the same assessor and put into four categories: excellent, good, fair, and poor. Operative time, blood loss, hospital expense, and complications were also recorded. All patients achieved successful radiographic fusion at 2 years, and this was achieved at 1 year in 25 out of 27 patients. At 2 years, clinical results were excellent in 15patients, good in 10, fair in 1, and poor in 1. Regarding complications, one patient had a postoperative motor and sensory deficit of the nerve root. Reoperation was required in one patient due to migration of pedicle screws. No implant fractures or deformities occurred in any of the patients. PLIF using diagonal insertion of a single threaded cage with supplemental transpedicular screw/rod instrumentation enables sufficient decompression and solid interbody fusion to be achieved with minimal invasion of the posterior spinal elements. It is a clinically safer, easier, and more economical means of accomplishing PLIF.
PMCID: PMC3784842  PMID: 12709855
Lumbar Fusion cage Implant Transpedicular screw Interbody
7.  A Meta-Analysis of Unilateral versus Bilateral Pedicle Screw Fixation in Minimally Invasive Lumbar Interbody Fusion 
PLoS ONE  2014;9(11):e111979.
Study Design
Bilateral pedicle screw fixation (PS) after lumbar interbody fusion is a widely accepted method of managing various spinal diseases. Recently, unilateral PS fixation has been reported as effective as bilateral PS fixation. This meta-analysis aimed to comparatively assess the efficacy and safety of unilateral PS fixation and bilateral PS fixation in the minimally invasive (MIS) lumbar interbody fusion for one-level degenerative lumbar spine disease.
MEDLINE/PubMed, EMBASE, BIOSIS Previews, and Cochrane Library were searched through March 30, 2014. Randomized controlled trials (RCTs) and controlled clinical trials (CCTs) on unilateral versus bilateral PS fixation in MIS lumbar interbody fusion that met the inclusion criteria and the methodological quality standard were retrieved and reviewed. Data on participant characteristics, interventions, follow-up period, and outcomes were extracted from the included studies and analyzed by Review Manager 5.2.
Six studies (5 RCTs and 1 CCT) involving 298 patients were selected. There were no significant differences between unilateral and bilateral PS fixation procedures in fusion rate, complications, visual analogue score (VAS) for leg pain, VAS for back pain, Oswestry disability index (ODI). Both fixation procedures had similar length of hospital stay (MD = 0.38, 95% CI = −0.83 to 1.58; P = 0.54). In contrast, bilateral PS fixation was associated with significantly more intra-operative blood loss (P = 0.002) and significantly longer operation time (P = 0.02) as compared with unilateral PS fixation.
Unilateral PS fixation appears as effective and safe as bilateral PS fixation in MIS lumbar interbody fusion but requires less operative time and causes less blood loss, thus offering a simple alternative approach for one-level lumbar degenerative disease.
PMCID: PMC4223107  PMID: 25375315
8.  Clinical and radiographic outcomes with L4–S1 axial lumbar interbody fusion (AxiaLIF) and posterior instrumentation: a multicenter study 
Previous studies have confirmed the benefits and limitations of the presacral retroperitoneal approach for L5–S1 interbody fusion. The purpose of this study was to determine the safety and effectiveness of the minimally invasive axial lumbar interbody approach (AxiaLIF) for L4–S1 fusion.
In this retrospective series, 52 patients from four clinical sites underwent L4–S1 interbody fusion with the AxiaLIF two-level system with minimum 2-year clinical and radiographic follow-up (range: 24–51 months). Outcomes included back pain severity (on a 10-point scale), the Oswestry Disability Index (ODI), and Odom’s criteria. Flexion and extension radiographs, as well as computed tomography scans, were evaluated to determine fusion status. Longitudinal outcomes were assessed with repeated measures analysis of variance.
Mean subject age was 52 ± 11 years and the male:female ratio was 1:1. Patients sustained no intraoperative bowel or vascular injury, deep infection, or neurologic complication. Median procedural blood loss was 220 cc and median length of hospital stay was 3 days. At 2-year follow-up, mean back pain had improved 56%, from 7.7 ± 1.6 at baseline to 3.4 ± 2.7 (P < 0.001). Back pain clinical success (ie, ≥30% improvement from baseline) was achieved in 39 (75%) patients at 2 years. Mean ODI scores improved 42%, from 60% ± 16% at baseline to 35% ± 27% at 2 years (P < 0.001). ODI clinical success (ie, ≥30% improvement from baseline) was achieved in 26 (50%) patients. At final follow-up, 45 (87%) patients were rated as good or excellent, five as fair, and two as poor by Odom’s criteria. Interbody fusion observed on imaging was achieved in 97 (93%) of 104 treated interspaces. During follow-up, five patients underwent reoperation on the lumbar spine, including facet screw removal (two), laminectomy (two), and transforaminal lumbar interbody fusion (one).
The AxiaLIF two-level device is a safe, effective treatment adjunct for patients with L4–S1 disc pathology resistant to conservative treatments.
PMCID: PMC3787926  PMID: 24092998
AxiaLIF; axial presacral fusion; interbody; outcomes; two-level fusion
9.  Minimally invasive 360° instrumented lumbar fusion 
European Spine Journal  2000;9(Suppl 1):S051-S056.
A retrospective preliminary study was undertaken of combined minimally invasive instrumented lumbar fusion utilizing the BERG (balloon-assisted endoscopic retroperitoneal gasless) approach ¶anteriorly, and a posterior small-incision approach with translaminar screw fixation and posterolateral ¶fusion. The study aimed to quantify the clinical and radiological results using this combined technique. The traditional minimally invasive approach to the anterior lumbar spine involves gas insufflation and provides reliable access only to L5-S1 and in some cases L4-5. A gas-mediated approach yields many technical drawbacks to performing spinal surgery. A minimally invasive posterior approach involving suprafascial pedicle screw instrumentation has been developed, but without widespread use. Translaminar facet fixation may be a viable alternative to transpedicular fixation in a 360° instrumented fusion model. Past studies have shown open 360° instrumented lumbar fusion yields high arthrodesis rates. The study examined the cases of 46 patients who underwent successful 360° instrumented lumbar fusion using a combined minimally invasive approach. Anterior lumbar interbody fusion (ALIF) at one or two levels was performed through the BERG approach; a gasless retroperitoneal approach to the lumbar spine allowing the use ¶of standard anterior instrumentation. Posteriorly, all patients underwent successful decompression, translaminar fixation, and posterolateral fusion at one or two levels through ¶one small (2.5–5.0 cm) incision. Results showed mean hospital stay of 2.02 days; mean combined blood loss was 255 cc; and mean pain relief was 56%, with 75.5% of patients reporting good, excellent, or total pain relief. Forty-two of 46 patients (93.2%) achieved a solid fusion ¶24 months after surgery. A total of 47% of all patients working prior to surgery returned to work following surgery. The study showed that minimally invasive 360° instrumented lumbar fusion, when performed utilizing these approaches, yields a high rate of solid arthrodesis (93.3%), good pain relief, short hospital stays, low blood losses, accelerated rehabilitation, and a quick return to the workforce. The BERG approach offers technical advantages over the traditional gas-mediated laparoscopic approach to the anterior lumbar spine.
PMCID: PMC3611432
Key words Minimally Invasive; 360° lumbar fusion; Combined ¶anteroposterior; Gasless endoscopy; Translaminar fixation
10.  Minimally invasive transforaminal lumbar interbody fusion 
Indian Journal of Orthopaedics  2014;48(6):562-567.
The use of minimally invasive surgical (MIS) techniques represents the most recent modification of methods used to achieve lumbar interbody fusion. The advantages of minimally invasive spinal instrumentation techniques are less soft tissue injury, reduced blood loss, less postoperative pain and shorter hospital stay while achieving clinical outcomes comparable with equivalent open procedure. The aim was to study the clinicoradiological outcome of minimally invasive transforaminal lumbar interbody fusion.
Materials and Methods:
This prospective study was conducted on 23 patients, 17 females and 6 males, who underwent MIS-transforaminal lumbar interbody fusion (TLIF) followed up for a mean 15 months. The subjects were evaluated for clinical and radiological outcome who were manifested by back pain alone (n = 4) or back pain with leg pain (n = 19) associated with a primary diagnosis of degenerative spondylolisthesis, massive disc herniation, lumbar stenosis, recurrent disc herniation or degenerative disc disease. Paraspinal approach was used in all patients. The clinical outcome was assessed using the revised Oswestry disability index and Macnab criteria.
The mean age of subjects was 55.45 years. L4-L5 level was operated in 14 subjects, L5-S1 in 7 subjects; L3-L4 and double level was fixed in 1 patient each. L4-L5 degenerative listhesis was the most common indication (n = 12). Average operative time was 3 h. Fourteen patients had excellent results, a good result in 5 subjects, 2 subjects had fair results and 2 had poor results. Three patients had persistent back pain, 4 patients had residual numbness or radiculopathy. All patients had a radiological union except for 1 patient.
The study demonstrates a good clinicoradiological outcome of minimally invasive TLIF. It is also superior in terms of postoperative back pain, blood loss, hospital stay, recovery time as well as medication use.
PMCID: PMC4232824  PMID: 25404767
Degenerative spine; lumbar fusion; minimally invasive transforaminal lumbar interbody fusion; spondylolisthesis; Spinal arthritis; spondyloarthritis; spondylolisthesis; minimally invasive; spinal fusion
11.  Mini-open lateral retroperitoneal lumbar spine approach using psoas muscle retraction technique. Technical report and initial results on six patients 
European Spine Journal  2013;22(9):2113-2119.
The main aim of this paper was to report reproducible method of lumbar spine access via a lateral retroperitoneal route.
The authors conducted a retrospective analysis of the technical aspects and clinical outcomes of six patients who underwent lateral multilevel retroperitoneal interbody fusion with psoas muscle retraction technique. The main goal was to develop a simple and reproducible technique to avoid injury to the lumbar plexus.
Six patients were operated at 15 levels using psoas muscle retraction technique. All patients reported improvement in back pain and radiculopathy after the surgery. The only procedure-related transient complication was weakness and pain on hip flexion that resolved by the first follow-up visit.
Psoas retraction technique is a reliable technique for lateral access to the lumbar spine and may avoid some of the complications related to traditional minimally invasive transpsoas approach.
Electronic supplementary material
The online version of this article (doi:10.1007/s00586-013-2931-1) contains supplementary material, which is available to authorized users.
PMCID: PMC3777064  PMID: 23904000
Retroperitoneal approach; Interbody fusion; Psoas muscle; Lumbar plexus
12.  Economics of less invasive spinal surgery: an analysis of hospital cost differences between open and minimally invasive instrumented spinal fusion procedures during the perioperative period 
There is great debate about the costs and benefits of technology-driven medical interventions such as instrumented lumbar fusion. With most analyses using charge data, the actual costs incurred by medical institutions performing these procedures are not well understood. The object of the current study was to examine the differences in hospital operating costs between open and minimally invasive spine surgery (MIS) during the perioperative period.
Data were collected in the form of a prospective registry from a community hospital after specific Institutional Review Board approval was obtained. The analysis included consecutive adult patients being surgically treated for degenerative conditions of the lumbar spine, with either an MIS or open approach for two-level instrumented lumbar fusion. Patient outcomes and costs were collected for the perioperative period. Hospital operating costs were grouped by hospitalization/operative procedure, transfusions, reoperations, and residual events (health care interactions).
One hundred and one open posterior lumbar interbody fusion (Open group) and 109 MIS patients were treated primarily for stenosis coupled with instability (39.6% and 59.6%, respectively). Mean total hospital costs were $27,055.53 for the Open group and $24,320.16 for the MIS group. This represents a statistically significant cost savings of $2,825.37 (10.4% [95% confidence interval: $522.51–$5,128.23]) when utilizing MIS over traditional Open techniques. Additionally, residual events, complications, and blood transfusions were significantly more frequent in the Open group, compared to the MIS group.
Conclusions/level of evidence
Utilizing minimally invasive techniques for instrumented spinal fusion results in decreased hospital operating costs compared to similar open procedures in the early perioperative period. Additionally, patient benefits of minimally invasive techniques include significantly less blood loss, shorter hospital stays, lower complication rate, and a lower number of residual events. Long-term outcome comparisons are needed to evaluate the efficacy of the two treatments. Level of evidence: III
Clinical relevance
This work represents a true cost-of-operating comparison between open and MIS approaches for lumbar spine fusion, which has relevance to surgeons, hospitals and payers in medical decision-making.
PMCID: PMC3430081  PMID: 22952415
lumbar; degenerative; complications; MIS; residual events
13.  Artificial Discs for Lumbar and Cervical Degenerative Disc Disease –Update 
Executive Summary
To assess the safety and efficacy of artificial disc replacement (ADR) technology for degenerative disc disease (DDD).
Clinical Need
Degenerative disc disease is the term used to describe the deterioration of 1 or more intervertebral discs of the spine. The prevalence of DDD is roughly described in proportion to age such that 40% of people aged 40 years have DDD, increasing to 80% among those aged 80 years or older. Low back pain is a common symptom of lumbar DDD; neck and arm pain are common symptoms of cervical DDD. Nonsurgical treatments can be used to relieve pain and minimize disability associated with DDD. However, it is estimated that about 10% to 20% of people with lumbar DDD and up to 30% with cervical DDD will be unresponsive to nonsurgical treatments. In these cases, surgical treatment is considered. Spinal fusion (arthrodesis) is the process of fusing or joining 2 bones and is considered the surgical gold standard for DDD.
Artificial disc replacement is the replacement of the degenerated intervertebral disc with an artificial disc in people with DDD of the lumbar or cervical spine that has been unresponsive to nonsurgical treatments for at least 6 months. Unlike spinal fusion, ADR preserves movement of the spine, which is thought to reduce or prevent the development of adjacent segment degeneration. Additionally, a bone graft is not required for ADR, and this alleviates complications, including bone graft donor site pain and pseudoarthrosis. It is estimated that about 5% of patients who require surgery for DDD will be candidates for ADR.
Review Strategy
The Medical Advisory Secretariat conducted a computerized search of the literature published between 2003 and September 2005 to answer the following questions:
What is the effectiveness of ADR in people with DDD of the lumbar or cervical regions of the spine compared with spinal fusion surgery?
Does an artificial disc reduce the incidence of adjacent segment degeneration (ASD) compared with spinal fusion?
What is the rate of major complications (device failure, reoperation) with artificial discs compared with surgical spinal fusion?
One reviewer evaluated the internal validity of the primary studies using the criteria outlined in the Cochrane Musculoskeletal Injuries Group Quality Assessment Tool. The quality of concealment allocation was rated as: A, clearly yes; B, unclear; or C, clearly no. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to evaluate the overall quality of the body of evidence (defined as 1 or more studies) supporting the research questions explored in this systematic review. A random effects model meta-analysis was conducted when data were available from 2 or more randomized controlled trials (RCTs) and when there was no statistical and or clinical heterogeneity among studies. Bayesian analyses were undertaken to do the following:
Examine the influence of missing data on clinical success rates;
Compute the probability that artificial discs were superior to spinal fusion (on the basis of clinical success rates);
Examine whether the results were sensitive to the choice of noninferiority margin.
Summary of Findings
The literature search yielded 140 citations. Of these, 1 Cochrane systematic review, 1 RCT, and 10 case series were included in this review. Unpublished data from an RCT reported in the grey literature were obtained from the manufacturer of the device. The search also yielded 8 health technology assessments evaluating ADR that are also included in this review.
Six of the 8 health technology assessments concluded that there is insufficient evidence to support the use of either lumbar or cervical ADR. The results of the remaining 2 assessments (one each for lumbar and cervical ADR) led to a National Institute for Clinical Excellence guidance document supporting the safety and effectiveness of lumbar and cervical ADR with the proviso that an ongoing audit of all clinical outcomes be undertaken owing to a lack of long-term outcome data from clinical trials.
Regarding lumbar ADR, data were available from 2 noninferiority RCTs to complete a meta-analysis. The following clinical, health systems, and adverse event outcome measures were synthesized: primary outcome of clinical success, Oswestry Disability Index (ODI) scores, pain VAS scores, patient satisfaction, duration of surgery, amount of blood loss, length of hospital stay, rate of device failure, and rate of reoperation.
The meta-analysis of overall clinical success supported the noninferiority of lumbar ADR compared with spinal fusion at 24-month follow-up. Of the remaining clinical outcome measures (ODI, pain VAS scores, SF-36 scores [mental and physical components], patient satisfaction, and return to work status), only patient satisfaction and scores on the physical component scale of the SF-36 questionnaire were significantly improved in favour of lumbar ADR compared with spinal fusion at 24 months follow-up. Blood loss and surgical time showed statistical heterogeneity; therefore, meta-analysis results are not interpretable. Length of hospital stay was significantly shorter in patients receiving the ADR compared with controls. Neither the number of device failures nor the number of neurological complications at 24 months was statistically significantly different between the ADR and fusion treatment groups. However, there was a trend towards fewer neurological complications at 24 months in the ADR treatment group compared with the spinal fusion treatment group.
Results of the Bayesian analyses indicated that the influence of missing data on the outcome measure of clinical success was minimal. The Bayesian model indicated that the probability for ADR being better than spinal fusion was 79%. The probability of ADR being noninferior to spinal fusion using a -10% noninferiority bound was 92%, and using a -15% noninferiority bound was 94%. The probability of artificial discs being superior to spinal fusion in a future trial was 73%.
Six case series were reviewed, mainly to characterize the rate of major complications for lumbar ADR. The Medical Advisory Secretariat defined a major complication as any reoperation; device failure necessitating a revision, removal or reoperation; or life-threatening event. The rates of major complications ranged from 0% to 13% per device implanted. Only 1 study reported the rate of ASD, which was detected in 2 (2%) of the 100 people 11 years after surgery.
There were no RCT data available for cervical ADR; therefore, data from 4 case series were reviewed for evidence of effectiveness and safety. Because data were sparse, the effectiveness of cervical ADR compared with spinal fusion cannot be determined at this time.
The rate of major complications was assessed up to 2 years after surgery. It was found to range from 0% to 8.1% per device implanted. The rate of ASD is not reported in the clinical trial literature.
The total cost of a lumbar ADR procedure is $15,371 (Cdn; including costs related to the device, physician, and procedure). The total cost of a lumbar fusion surgery procedure is $11,311 (Cdn; including physicians’ and procedural costs).
Lumbar Artificial Disc Replacement
Since the 2004 Medical Advisory Secretariat health technology policy assessment, data from 2 RCTs and 6 case series assessing the effectiveness and adverse events profile of lumbar ADR to treat DDD has become available. The GRADE quality of this evidence is moderate for effectiveness and for short-term (2-year follow-up) complications; it is very low for ASD.
The effectiveness of lumbar ADR is not inferior to that of spinal fusion for the treatment of lumbar DDD. The rates for device failure and neurological complications 2 years after surgery did not differ between ADR and fusion patients. Based on a Bayesian meta-analysis, lumbar ADR is 79% superior to lumbar spinal fusion.
The rate of major complications after lumbar ADR is between 0% and 13% per device implanted. The rate of ASD in 1 case series was 2% over an 11-year follow-up period.
Outcome data for lumbar ADR beyond a 2-year follow-up are not yet available.
Cervical Artificial Disc Replacement
Since the 2004 Medical Advisory Secretariat health technology policy assessment, 4 case series have been added to the body of evidence assessing the effectiveness and adverse events profile of cervical ADR to treat DDD. The GRADE quality of this evidence is very low for effectiveness as well as for the adverse events profile. Sparse outcome data are available.
Because data are sparse, the effectiveness of cervical ADR compared with spinal fusion cannot be determined at this time.
The rate of major complications was assessed up to 2 years after surgery; it ranged from 0% to 8.1% per device implanted. The rate of ASD is not reported in the clinical trial literature.
PMCID: PMC3379529  PMID: 23074480
14.  Minimally invasive versus open transforaminal lumbar interbody fusion 
Available clinical data are insufficient for comparing minimally invasive (MI) and open approaches for transforaminal lumbar interbody fusion (TLIF). To date, a paucity of literature exists directly comparing minimally invasive (MI) and open approaches for transforaminal lumbar interbody fusion (TLIF). The purpose of this study was to directly compare safety and effectiveness for these two surgical approaches.
Materials and Methods
Open or minimally invasive TLIF was performed in 63 and 76 patients, respectively. All consecutive minimally invasive TLIF cases were matched with a comparable cohort of open TLIF cases using three variables: diagnosis, number of spinal levels, and history of previous lumbar surgery. Patients were treated for painful degenerative disc disease with or without disc herniation, spondylolisthesis, and/or stenosis at one or two spinal levels. Clinical outcome (self-report measures, e.g., visual analog scale (VAS), patient satisfaction, and MacNab's criteria), operative data (operative time, estimated blood loss), length of hospitalization, and complications were assessed. Average follow-up for patients was 37.5 months.
The mean change in VAS scores postoperatively was greater (5.2 vs. 4.1) in theopen TLIF patient group (P = 0.3). MacNab's criteria score was excellent/good in 67% and 70% (P = 0.8) of patients in open and minimally invasive TLIF groups, respectively. The overall patient satisfaction was 72.1% and 64.5% (P = 0.4) in open and minimally invasive TLIF groups, respectively. The total mean operative time was 214.9 min for open and 222.5 min for minimally invasive TLIF procedures (P = 0.5). The mean estimated blood loss for minimally invasive TLIF (163.0 ml) was significantly lower (P < 0.0001) than the open approach (366.8 ml). The mean duration of hospitalization in the minimally invasive TLIF (3 days) was significantly shorter (P = 0.02) than the open group (4.2 days). The total rate of neurological deficit was 10.5% in the minimally invasive TLIF group compared to 1.6% in the open group (P = 0.02).
Minimally invasive TLIF technique may provide equivalent long-term clinical outcomes compared to open TLIF approach in select population of patients. The potential benefit of minimized tissue disruption, reduced blood loss, and length of hospitalization must be weighted against the increased rate of neural injury-related complications associated with a learning curve.
PMCID: PMC2908364  PMID: 20657693
Clinical outcomes; Complications; Degenerative lumbar spine; Lumbar fusion; Minimally invasive approach; Open approach; Transforaminal lumbar interbody fusion
15.  The ALIF concept 
European Spine Journal  2000;9(Suppl 1):S035-S043.
The terms ‘minimally invasive’ or ‘less invasive surgery’ have been used recently to describe surgical approaches or operations that are performed with less trauma to anatomical structures on the way to or surrounding the surgical ‘target area’. These types of surgical procedures are usually performed with the help of ‘high-tech’ instruments such as surgical endoscopes or surgical microscopes, modern video techniques and automated instruments. Within the last 10 years, such techniques have been developed in the field of spinal surgery. The application of minimally or less invasive procedures has concentrated predominantly on anterior approaches to the thoracic and lumbar spine. This article describes two anterior approach techniques for performing anterior lumbar interbody fusion (ALIF) through a minimally invasive retroperitoneal or transperitoneal approach. The technical principles are microsurgical modifications of traditional anterior approaches to the lumbar spine. Through small (4-cm) skin incisions, the target area can be exposed. Preliminary results suggest decreased peri - and postoperative morbidity, less blood loss, earlier rehabilitation and acceptable complication rates. The technique is currently used by the author for all patients requiring anterior lumbar interbody fusion.
PMCID: PMC3611443
Key words Microsurgery; Lumbar spine; Mini ALIF; Anterior lumbar interbody fusion
16.  Endoscopic Foraminal Decompression Preceding Oblique Lateral Lumbar Interbody Fusion To Decrease The Incidence Of Post Operative Dysaesthesia 
Lumbar interbody fusion has become a well established method to diminish axial back pain as well as radiculopathy in patients with degenerative disc disease, stenosis, and instability. The concept of indirect decompression of the neural foramen and spinal canal while performing fusion became popular in the mid 1990’s with description of ALIF techniques. Morphometric analysis confirmed the extent of decompression of posterior elements with interbody height restoration. In an attempt to diminish potential complications associated with anterior or posterior approaches to the spine for interbody fusion, and with the hope of accomplishing fusion in a less invasive manner, lateral lumbar interbody fusion has become quite popular. This transpsoas approach to the disc space has been associated with a high incidence of neurologic complications. Even though this is the first technique to routinely recommend EMG monitoring to increase safety in the approach, neurologic injuries still occur. A newer oblique lateral lumbar interbody (OLLIF) approach has recently been described to lessen the incidence of neurologic injury. This technique also advocates use of EMG testing to lessen neurologic trauma. In spite of this precaution, neurologic insult has not been eliminated. In fact, even in patients whose electrical stimulation thresholds suggested a safe entry space into the disc, transient dysaesthesia continues to occur in 20-25 percent of cases.
This pilot study reflects data and observations of a subset of patients treated with endoscopic foraminotomy preceding oblique lateral lumbar interbody fusion (OLLIF) to assess specifically potential improvements in dysaesthesia rates.
A select subset of patients undergoing OLLIF failed to meet electrodiagnostic criteria for safe disc access through Kambin’s triangle. These patients underwent an endoscopic foraminotomy and exiting nerve decompression prior to discectomy, endplate preparation and cage insertion.
Dysaesthesia did not occur in these patients whom otherwise would have likely been at risk for neurologic deficit.
These findings suggest that patients at risk for neurologic insult during oblique lateral lumbar interbody fusion can be protected by foraminoplasty.
PMCID: PMC4325491
Oblique Lateral Lumbar Interbody Fusion; endoscopic foraminoplasty; Dysaesthesia; Dysaesthesia rates in OLLIF; Lumbar interbody fusion
17.  Lumbar degenerative spinal deformity: Surgical options of PLIF, TLIF and MI-TLIF 
Indian Journal of Orthopaedics  2010;44(2):159-162.
Degenerative disease of the lumbar spine is common in ageing populations. It causes disturbing back pain, radicular symptoms and lowers the quality of life. We will focus our discussion on the surgical options of posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) and minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for lumbar degenerative spinal deformities, which include symptomatic spondylolisthesis and degenerative scoliosis. Through a description of each procedure, we hope to illustrate the potential benefits of TLIF over PLIF. In a retrospective study of 53 ALIF/PLIF patients and 111 TLIF patients we found reduced risk of vessel and nerve injury in TLIF patients due to less exposure of these structures, shortened operative time and reduced intra-operative bleeding. These advantages could be translated to shortened hospital stay, faster recovery period and earlier return to work. The disadvantages of TLIF such as incomplete intervertebral disc and vertebral end-plate removal and potential occult injury to exiting nerve root when under experienced hands are rare. Hence TLIF remains the mainstay of treatment in degenerative deformities of the lumbar spine. However, TLIF being a unilateral transforaminal approach, is unable to decompress the opposite nerve root. This may require contralateral laminotomy, which is a fairly simple procedure. The use of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) to treat degenerative lumbar spinal deformity is still in its early stages. Although the initial results appear promising, it remains a difficult operative procedure to master with a steep learning curve. In a recent study comparing 29 MI-TLIF patients and 29 open TLIF, MI-TLIF was associated with longer operative time, less blood loss, shorter hospital stay, with no difference in SF-36 scores at six months and two years. Whether it can replace traditional TLIF as the surgery of choice for degenerative lumbar deformity remains unknown and more studies are required to validate the safety and efficiency.
PMCID: PMC2856390  PMID: 20419002
Degenerative spine; lumbar spine fusion; minimally invasive transforaminal fusion
18.  The lateral transpsoas approach to the lumbar and thoracic spine: A review 
Surgical Neurology International  2012;3(Suppl 3):S198-S215.
In the last several years, the lateral transpsoas approach to the thoracic and lumbar spine, also known as extreme lateral interbody fusion (XLIF) or direct lateral interbody fusion (DLIF), has become an increasingly common method to achieve fusion. Several recent large series describe several advantages to this approach, including less tissue dissection, smaller incisions, decreased operative time, blood loss, shorter hospital stay, reduced postoperative pain, enhanced fusion rates, and the ability to place instrumentation through the same incision. Indications for this approach have expanded and now include degenerative disease, tumor, deformity, and infection.
A lateral X-ray confirms that the patient is in a truly lateral position. Next, a series of tubes and dilators are used, along with fluoroscopy, to identify the mid-position of the disk to be incised. After continued dilation, the optimal site to enter the disk space is the midpoint of the disk, or a position slightly anterior to the midpoint of the disk. XLIF typically allows for a larger implant to be inserted compared to TLIF or PLIF, and, if necessary, instrumentation can be inserted percutaneously, which would allow for an overall minimally invasive procedure.
Fixation techniques appear to be equal between XLIF and more traditional approaches. Some caution should be exercised because common fusion levels of the lumbar spine, including L4-5 and L4-S1, are often inaccessible. In addition, XLIF has a unique set of complications, including neural injuries, psoas weakness, and thigh numbness.
Additional studies are required to further evaluate and monitor the short and long-term safety, efficacy, outcomes, and complications of XLIF procedures.
PMCID: PMC3422088  PMID: 22905326
Lateral transpsoas approach; extreme lateral interbody fusion; direct lateral interbody fusion; lumbar spine; lumbosacral plexus; surgical technique
19.  Comparison of conventional versus minimally invasive extraperitoneal approach for anterior lumbar interbody fusion 
European Spine Journal  2004;13(5):425-431.
The purpose of the study was to compare conventional versus minimally invasive extraperitoneal approach for anterior lumbar interbody fusion (ALIF). Fifty-six consecutive patients with spondylolisthesis, lumbar instability, or failed back syndrome were treated with ALIF between 1991 and 2001. The patients were retrospectively evaluated and divided in two groups: Group 1, consisting 33 patients, was treated with ALIF using the conventional retroperitoneal approach, and Group 2, consisting of 23 patients, was operated with the minimally invasive muscle-splitting approach for ALIF. The groups were comparable as regards age, indication of fusion, and diagnosis. All patients in both groups had fusion with autologous iliac crest grafts and posterior instrumentation with posterolateral fusion in the same sitting. Clinical evaluation was done by two questionnaires: the North American Spine Society (NASS) Lumbar Spine Outcome Assessment Instrument and the Nottingham Health Profile (NHP). Fusion rate was evaluated radiologically. Mean clinical follow-up was 5.5 years. There was no statistical difference in the occurrence of complications with both approaches nor with the fusion rates of 92% in group 1 and 84% in group 2 respectively. The minimally invasive extraperitoneal approach for ALIF was associated with significantly less intraoperative blood loss, operation time, and length of the skin incision. In addition, this approach showed significant improvement in postoperative back pain in comparison to the conventional approach for ALIF.
PMCID: PMC3476582  PMID: 15138863
ALIF; Conventional; Minimally invasive; Lumbar spine
20.  Minimally Invasive Transforaminal Lumbar Interbody Fusion with Unilateral Pedicle Screw Fixation: Comparison between Primary and Revision Surgery 
BioMed Research International  2014;2014:919248.
Minimally invasive surgery with a transforaminal lumbar interbody fusion (MIS TLIF) is an important minimally invasive fusion technique for the lumbar spine. Lumbar spine reoperation is challenging and is thought to have greater complication risks. The purpose of this study was to compare MIS TLIF with unilateral screw fixation perioperative results between primary and revision surgeries. This was a prospective study that included 46 patients who underwent MIS TLIF with unilateral pedicle screw. The patients were divided into two groups, primary and revision MIS TLIF, to compare perioperative results and complications. The two groups were similar in age, sex, and level of operation, and were not significantly different in the length of follow-up or clinical results. Although dural tears were more common with the revision group (primary 1; revision 4), operation time, blood loss, total perioperative complication, and fusion rates were not significantly different between the two groups. Both groups showed substantial improvements in VAS and ODI scores one year after surgical treatment. Revision MIS TLIF performed by an experienced surgeon does not necessarily increase the risk of perioperative complication compared with primary surgery. MIS TLIF with unilateral pedicle screw fixation is a valuable option for revision lumbar surgery.
PMCID: PMC4053265  PMID: 24949483
21.  The routine intra-operative use of pulse oximetry for monitoring can prevent severe thromboembolic complications in anterior surgery 
European Spine Journal  2011;20(12):2097-2102.
Anterior access to the lumbar spine is established for disc replacement surgery and anterior interbody fusion in the lumbar spine. The spine is accessed normally from the left side either by a transperitoneal or retroperitoneal approach through a midline or oblique skin incision. After reaching the retroperitoneum and depending on the level of exposure, the surgeon has to mobilise and retract the aorta or left common iliac artery, as well as the left common iliac vein or internal vena cava to the right lateral border to address the whole disc space. The left common iliac artery is especially stretched during intervertebral disc exposure putting it at a greater risk of adverse events. Not surprisingly, vascular adverse events like direct injuries, thrombosis and embolism are feared complications in anterior surgery. Permanent intra-operative left leg oxygen saturation surveillance via pulse oximetry can help detecting embolic situations thereby allowing immediate treatment minimising the leg ischemia or preventing limb loss.
Case report
In the presented case, a 61-year-old male patient undergoing a two-level anterior interbody fusion lost oxygen saturation in the left leg after vessel retraction for exposure. After cage insertion and release of the retractor blades, the pulse oximetry signal did not return and no pulses were found during instant Doppler investigation below the femoral artery, indicating severe embolism in the left leg. The left common iliac artery was clamped and opened showing a ruptured calcified plaque with adherent fresh thrombotic material. An endovascular embolectomy in the superficial and deep femoral artery revealed several small thrombi. An artherectomy of the common iliac artery followed by patch closure was performed. Immediately after clamp release, pulse oximetry returned and Doppler signals were detectable at the tibialis posterior and dorsalis pedis artery. Post-operative recovery was uneventful and pulses were palpable at all times.
Arterial adverse events in anterior access surgery are rare complications but none the less, it is of paramount importance to detect and treat these situations immediately. This case highlights the need of routine pulse monitoring during the whole anterior surgery to prevent embolic complications. Even manual pulse control might not be sufficient to rule out any distal embolic events creating severe leg ischemia.
PMCID: PMC3229741  PMID: 21800033
ALIF; Access complications; Embolectomy; Monitoring; Pulse oximetry; Lumbar disc replacement
22.  Clinical and radiographic outcomes of extreme lateral approach to interbody fusion with β-tricalcium phosphate and hydroxyapatite composite for lumbar degenerative conditions 
Historically, iliac crest bone graft has been used as the graft of choice for lumbar spine fusion procedures. Because fusion techniques have become less invasive, the demand for minimally disruptive grafting options has increased. This prospective study was performed to assess clinical and radiographic outcomes of patients treated with an iliac crest bone graft alternative and lateral lumbar interbody fusion.
Fifty degenerative lumbar patients were treated with the extreme lateral approach to interbody fusion and a β-tricalcium phosphate–hydroxyapatite graft with bone marrow aspirate (BMA) at 1 or 2 adjacent levels. BMA was collected from the iliac crest with a bone aspiration needle and applied to the FormaGraft (NuVasive, Inc., San Diego, California) in a 1:1 ratio. Radiolucent cages were filled with FormaGraft strips, granules, or blocks and implanted in a standard fashion. Clinical data were collected at baseline, 6 weeks, and 3, 6, and 12 months and included visual analog scale, Oswestry Disability Index, and Short Form 36 patient-reported assessments. Fusion assessments were made from neutral anteroposterior/lateral radiographs, lateral flexion/extension radiographs, and computed tomography images taken at least 12 months after surgery.
Forty-four patients treated at 49 levels completed follow-up. The mean patient age was 54.7 ± 10.8 years, and mean body mass index was 30.8 ± 7.7 kg/m2. Radiographic fusion was observed in 41 of 44 assessed levels (93.2%). Blood loss was less than 100 mL in 95.5% of patients. Of the patients, 93.2% spent 1 night or less in the hospital. By the 6-week follow-up, all clinical outcomes were significantly improved (P < .05). Improvements were maintained or increased throughout the course of follow-up.
This report shows that the technique of extreme lateral approach to interbody fusion in combination with FormaGraft and BMA in the interbody space is a safe and effective treatment option for interbody fusion of the lumbar spine when compared with other approaches and biologic options.
PMCID: PMC4300873
Obese; Spine; Lumbar fusion; β-Tricalcium phosphate; Synthetic; Graft; BMA
23.  Arthrodesis to L5 versus S1 in long instrumentation and fusion for degenerative lumbar scoliosis 
European Spine Journal  2009;18(4):531-537.
There is a debate regarding the distal fusion level for degenerative lumbar scoliosis. Whether a healthy L5-S1 motion segment should be included or not in the fusion remains controversial. The purpose of this study was to determine the optimal indication for the fusion to the sacrum, and to compare the results of distal fusion to L5 versus the sacrum in the long instrumented fusion for degenerative lumbar scoliosis. A total of 45 patients who had undergone long instrumentation and fusion for degenerative lumbar scoliosis were evaluated with a minimum 2 year follow-up. Twenty-four patients (mean age 63.6) underwent fusion to L5 and 21 patients (mean age 65.6) underwent fusion to the sacrum. Supplemental interbody fusion was performed in 12 patients in the L5 group and eleven patients in the sacrum group. The number of levels fused was 6.08 segments (range 4–8) in the L5 group and 6.09 (range 4–9) in the sacrum group. Intraoperative blood loss (2,754 ml versus 2,938 ml) and operative time (220 min versus 229 min) were similar in both groups. The Cobb angle changed from 24.7° before surgery to 6.8° after surgery in the L5 group, and from 22.8° to 7.7° in the sacrum group without statistical difference. Correction of lumbar lordosis was statistically better in the sacrum group (P = 0.03). Less correction of lumbar lordosis in the L5 group seemed to be associated with subsequent advanced L5-S1 disc degeneration. The change of coronal and sagittal imbalance was not different in both groups. Subsequent advanced L5-S1 disc degeneration occurred in 58% of the patients in the L5 group. Symptomatic adjacent segment disease at L5-S1 developed in five patients. Interestingly, the development of adjacent segment disease was not related to the preoperative grade of disc degeneration, which proved minimal degeneration in the five patients. In the L5 group, there were nine patients of complications at L5-S1 segment, including adjacent segment disease at L5-S1 and loosening of L5 screws. Seven of the nine patients showed preoperative sagittal imbalance and/or lumbar hypolordosis, which might be risk factors of complications at L5-S1. For the patients with sagittal imbalance and lumbar hypolordosis, L5-S1 should be included in the fusion even if L5-S1 disc was minimal degeneration.
PMCID: PMC2899474  PMID: 19165507
Adult spinal deformity; Degenerative lumbar scoliosis; Distal fusion level; L5-S1 disc; Disc degeneration
24.  Minimally invasive or open transforaminal lumbar interbody fusion as revision surgery for patients previously treated by open discectomy and decompression of the lumbar spine 
European Spine Journal  2010;20(4):623-628.
Minimally invasive lumbar fusion techniques have been developed in recent 20 years. The goals of these procedures are to reduce approach-related soft tissue injury, postoperative pain, and disability while allowing the surgery to be conducted in an effective manner. There have been no prospective clinical reports published on the comparison of minimally invasive transforaminal lumbar interbody fusion as revision surgery for patients previously treated by open discectomy and decompression or a traditional open approach. A prospective clinical study was performed by evaluating the clinical and radiographic results of minimally invasive transforaminal lumbar interbody fusion as an alternative new technique in the revision surgery for patients previously treated by open procedure. 52 patients (28 M, 24 F) with an average age of 55.7 (31–76) were prospectively evaluated. All patients who had previous discectomy (n = 13), hemilaminectomy (n = 16), laminectomy (n = 12) and facetectomy (n = 11) underwent monosegmental and bisegmental minimally invasive transforaminal lumbar interbody fusion (MiTLIF) (n = 25) or open transforaminal lumbar interbody fusion (OTLIF) (n = 27) by two experienced surgeons at one hospital, from March 2006 to October 2008 (minimum 12-month follow-up). The following data were compared between the two groups: the clinical and radiographic results, operative time, blood loss, X-ray exposure time, postoperative back pain, and complications. Clinical outcome was assessed using the visual analogue scale and the Oswestry disability index (ODI). The operative time and clinical and radiographic results were basically identical in both groups. Comparing with the OTLIF group, the MiTLIF group had significantly less blood loss and less postoperative back pain at the second day postoperatively. The radiation time was significantly longer in the MiTLIF group. Complications included three cases of small dural tear in the MiTLIF group. There were five cases of dural tear and two cases of superficial wound infection in the OTLIF group. One case of nonunion was observed from each group. Minimally invasive TLIF is a safe and effective procedure for treatment of selected revision patients previously treated by open surgery with some potential advantages. However, this technique needs longer X-ray exposure time.
PMCID: PMC3065602  PMID: 20927557
Comparison; Revision spine surgery; Minimally invasive transforaminal lumbar interbody fusion; Failed lumbar surgery
25.  Outcome of single level instrumented posterior lumbar interbody fusion using corticocancellous laminectomy bone chips 
Indian Journal of Orthopaedics  2011;45(6):500-503.
Interbody fusion surgery has been considered by many to be a treatment of choice for instability in lumbar degenerative disc disease. A posterior lumbar interbody fusion (PLIF) has the advantages of spinal canal decompression, anterior column reconstruction, and reduction of the sagittal slips from a single posterior approach. The PLIF using double cage was a standard practice till many studies reported comparable results and lesser complications with single cage. Iliac crest was considered as an appropriate source of bone graft until comparable spinal fusion rates using local bone graft and cage emerged. Till date, there has been no report of corticocancellous laminectomy bone chips alone being used for spinal fusion. In this paper, we present radiologic results of single level instrumented PLIF, where in only corticocancellous laminectomy bone chips were used as a fusion device.
Materials and Methods:
It is a retrospective cohort study of 35 consecutive patients, who underwent single level instrumented PLIF surgery, wherein only locally obtained bone chips was used for spinal fusion. The average follow-up was 26 months. The indications for the surgery were as follows: 19 patients had disc herniations, with back pain of instability type, normal disc height on radiology. Ten patients had grade 1 spondylolisthesis, with significant back pain and translational instability on radiography. Three patients were redo spine surgeries, and three patients had healed spondylodiscitis with significant back pain and instability. All patients were regularly followed up and decision of spinal fusion or no fusion was taken at 2 years using modified criteria of Lee.
Of total 35 patients, there were 24 males and 11 females, with a mean age of 41 years. There were 16 patients with definitive fusion, 15 patients with probable fusion, 04 patients with possible pseudoarthrosis, and no patient had definitive pseudoarthrosis. The mean time for fusion to occur was 18 months. The average loss of disc height, over 2 year follow up, was only 3 mm in 8 patients. Three patients had a localized kyphosis of more than 3° at the fusion level. The average blood loss was 356 ml and average operating time was 150 min.
Corticocancellous laminectomy bone chips alone can be used as a means of spinal fusion in patients with single level instrumented PLIF. This has got a good fusion rate.
PMCID: PMC3227352  PMID: 22144741
Corticocancellous laminectomy bone chips; Interbody cage; posterior lumbar interbody fusion

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