Previous papers on resorbable poly-l-lactide-co-d,l-lactide (PLDLLA) cages in spinal fusion have failed to report adequately on patient-centred clinical outcome measures. Also comparison of PLDLLA cage with a traditionally applicable counterpart has not been previously reported. This is the first randomized prospective study that assesses clinical outcome of PLDLLA cage compared with a poly-ether-ether-ketone (PEEK) implant. Twenty-six patients were randomly assigned to undergo instrumented posterior lumbar interbody fusion (PLIF) whereby either a PEEK cage or a PLDLLA cage was implanted. Clinical outcome based on visual analogue scale scores for leg pain and back pain, as well as Oswestry Disability Index (ODI) and SF-36 questionnaires were documented and analysed. When compared with preoperative values, all clinical parameters have significantly improved in the PEEK group at 2 years after surgery with the exception of SF-36 general health, SF-36 mental health and SF-36 role emotional scores. No clinical parameter showed significant improvement at 2 years after surgery compared with preoperative values in the PLDLLA patient group. Only six patients (50%) in the PLDLLA group showed improvement in the VAS scores for leg and back pain as well as the ODI, as opposed to 10 patients (71%) in the PEEK group. One-third of the patients in the PLDLLA group actually reported worsening of their pain scores and ODI. Three cases of mild to moderate osteolysis were seen in the PLDLLA group. Following up on our preliminary report, these 2-year results confirm the superiority of the PEEK implant to the resorbable PLDLLA implant in aiding spinal fusion and alleviating symptoms following PLIF in patients with degenerative spondylolisthesis associated with either canal stenosis or foramen stenosis or both and emanating from a single lumbar segment.
Lumbar interbody fusion; PEEK cage; PLDLLA; Resorbable cage
In this prospective study, our aim was to compare the clinical outcome of posterior lumbar interbody fusion (PLIF) and posterolateral fusion (PLF) in spondylolisthesis. A total of 138 patients with spondylolisthesis were randomly assigned to two groups: those operated on with pedicle screw fixation and posterior lumbar interbody fusion by autografting (PLIF), and those operated on with pedicle screw fixation and posterolateral fusion by autografting (PLF). The patients were followed-up for four years. Clinical evaluation was carried out using the Oswestry disability index (ODI) and pain index (VAS). Radiography was performed preoperatively and postoperatively to assess the fusion. Both surgical procedures were effective, but the PLF group showed more complications related to hardware biomechanics. There was no significant statistical difference in clinical and functional outcome in the two groups. The PLIF group presented a better fusion rate than the PLF group.
The authors hypothesized that the placement of the interspinous implant would show a similar clinical outcome to the posterior lumbar interbody fusion (PLIF) in patients having spinal stenosis with mild segmental instability and that this method would be superior to PLIF without significantly affecting degeneration at the adjacent segments. Forty two adult patients having degenerative spinal stenosis with mild segmental instabilit who underwent implantation of Coflex™ (Spine motion, Germany) or PLIF at L4-5 between January 2000 and December 2003 were consecutively selected and studied for one-year clinical outcome. At 12 months after surgery, both groups showed a significant improvement in the visual analogue scale score and Oswestry disability index score for both lower extremity pain and low back pain. However, the range of motion at the upper adjacent segments (L3-4) increased significantly after surgery in the PLIF group, which was not manifested in the Coflex™ group during the follow-up. The authors assumed that interspinous implantation can be an alternative treatment for the spinal stenosis with segmental instability in selected conditions posing less stress on the superior adjacent level than PLIF.
Spinal Stenosis; Outcome
Degenerative lumbar spinal stenosis (DLSS) has become increasingly common and is characterized by multilevel disc herniation and lumbar spondylolisthesis, which are difficult to treat. The current study aimed to evaluate the short-term clinical outcomes and value of the combined use of microendoscopic discectomy (MED) and minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for the treatment of multilevel DLSS with spondylolisthesis, and to compare the combination with traditional posterior lumbar interbody fusion (PLIF). A total of 26 patients with multilevel DLSS and spondylolisthesis underwent combined MED and MI-TLIF surgery using a single cage and pedicle rod-screw system. These cases were compared with 27 patients who underwent traditional PLIF surgery during the same period. Data concerning incision length, surgery time, blood loss, time of bed rest and Oswestry Disability Index (ODI) score prior to and following surgery were analyzed statistically. Statistical significance was reached in terms of incision length, blood loss and the time of bed rest following surgery (P<0.05), but there was no significant difference between the surgery time and ODI scores of the two groups. The combined use of MED and MI-TLIF has the advantages of reduced blood loss, less damage to the paraspinal soft tissue, shorter length of incision, shorter bed rest time, improved outcomes and shorter recovery times and has similar short-term clinical outcomes to traditional PLIF.
microendoscopic discectomy; minimally invasive transforaminal lumbar interbody fusion; posterior lumbar interbody fusion; lumbar spinal stenosis; lumbar spondylolisthesis
There has been no agreement among different authors on guidelines to specify the situations in which arthrodesis is justified in terms of results, risks and complications. The aim of this study was to identify preoperative predictors of outcome after decompressive lumbar surgery and instrumented posterolateral fusion. A prospective observational study design was performed on 203 consecutive patients. Potential preoperative predictors of outcome included sociodemographic factors as well as variables pertaining to the preoperative clinical situation, diagnosis, expectations and surgery. Separate multiple linear regression models were used to assess the association between selected predictors and outcome variables, defined as the improvement after 1 year on the visual analog scale (VAS) for back pain, VAS for leg pain, physical component scores (PCS) of SF-36 and Oswestry disability index (ODI). Follow-up was available for 184 patients (90.6%). Patients with higher educational level and optimistic preoperative expectations had a more favourable postoperative leg pain (VAS) and ODI. Smokers had less leg pain relief. Patients with better mental component score (emotional health) had greater ODI improvement. Less preoperative walking capacity predicted more leg pain relief. Patients with disc herniation had greater relief from back pain and more PCS and ODI improvement. More severe lumbar pain was predictive of less improvement on ODI and PCS. Age, sex, body mass index, analgesic use, surgeon, self-rated health, the number of decompressed levels and the length of fusion had no association with outcome. This study concludes that a higher educational level, optimistic expectations for improvement, the diagnosis of “disc herniation”, less walking capacity and good emotional health may significantly improve clinical outcome. Smoking and more severe lumbar pain are predictors of worse results.
Lumbar fusion; Risk factors; Predictor; Clinical outcome
The aim of this study was to evaluate the short-term radiological and functional outcome of surgical treatment for symptomatic, low-grade, adult isthmic spondylolisthesis. Twelve patients underwent a monosegmental fusion for symptomatic spondylolisthesis. Posterior reduction with pedicle screw instrumentation was followed by second-stage anterior interbody fusion with a cage. All patients underwent a decompressive laminectomy. At an average of 2.1 (range 1.4–3.0) years following surgery, all patients completed the Oswestry questionnaire, VAS back pain score and a questionnaire detailing their work status. Radiographs were evaluated for maintenance of reduction and fusion. The patients (nine male, three female; mean age 42, range 22–54 years) had experienced preoperative symptoms for an average of 38 (range 6–96) months. An average preoperative slip of 21% (range 11–36%) was reduced to 7% (range 0–17%). Reduction of slip was maintained at latest follow-up, at which time the average VAS score was 2.8 (range 0–8) and the average Oswestry score was 13 (range 0–32). All patients achieved a successful fusion. There were no postoperative nerve root deficits. All patients stated that they would be prepared to undergo the same procedure again if required. Seventy-five percent returned to their pre-symptom work status. Our findings suggest that posterior reduction and anterior fusion for low-grade adult isthmic spondylolisthesis may yield good functional short-term results. A high fusion rate and maintenance of reduction with a low complication rate may be expected. Further follow-up is necessary to evaluate long-term outcome.
Adult spondylolisthesis Spinal fusion Prostheses and implants
Clinical and radiological results of posterior dynamic stabilization using interspinous U (ISU, Coflex™, Paradigm Spine Inc.®, NY, USA) were analyzed in comparison with posterior lumbar interbody fusion (PLIF) in degenerative lumbar spinal stenosis (LSS).
A retrospective study was conducted for a consecutive series of 61 patients with degenerative LSS between May 2003 and December 2005. We included only the patients completed minimum 24 months follow up evaluation. Among them, 30 patients were treated with implantation of ISU after decompressive laminectomy (Group ISU) and 31 patients were treated with wide decompressive laminectomy and posterior lumbar interbody fusion (PLIF; Group PLIF). We evaluated visual analogue scale (VAS) and Oswestry Disability Index (ODI) for clinical outcomes (VAS, ODI), disc height ratio disc height (DH), disc height/vertebral body length ×100), static vertebral slip (VS) and depth of maximal radiolucent gap between ISU and spinous process) in preoperative, immediate postoperative and last follow up.
The mean age of group ISU (66.2 ± 6.7 years) was 6.2 years older than the mean age of group PLIF (60.4 ± 8.1 years; p = 0.003 ). In both groups, clinical measures improved significantly than preoperative values (p < 0.001). Operation time and blood loss was significantly shorter and lower in group ISU than group PLIF (p < 0.001). In group ISU, the DH increased transiently in immediate postoperative period (15.7 ± 4.5% → 18.6 ± 5.9%), however decreased significantly in last follow up (13.8 ± 6.6%, p = 0.027). Vertebral slip (VS) of spondylolisthesis in group ISU increased during postoperative follow-up (2.3 ± 3.3 → 8.7 ± 6.2, p = 0.040). Meanwhile, the postoperatively improved DH and VS was maintained in group PLIF in last follow up.
According to our result, implantation of ISU after decompressive laminectomy in degenerative LSS is less invasive and provides similar clinical outcome in comparison with the instrumented fusion. However, the device has only transient effect on the postoperative restoration of disc height and reduction of slip in spondylolisthesis. Therefore, in the biomechanical standpoint, it is hard to expect that use of Interspinous U in decompressive laminectomy for degenerative LSS had long term beneficial effect.
Degenerative spinal stenosis; Lumbar; Dynamic stabilization; Interspinous U; Coflex™; Posterior lumbar interbody fusion
Study design: Retrospective cohort study.
Clinical question: Do more adult patients affected by low grade isthmic spondylolisthesis have significant clinical and radiological improvement following posterior lumbar interbody fusion (PLIF) than those who receive posterolateral fusion (PLF)?
Methods: One hundred and fourteen patients affected by adult low grade isthmic spondylolisthesis, treated with posterior lumbar interbody fusion or posterolateral fusion, were reviewed. Clinical outcome was assessed by means of the questionnaires ODI, RMDQ and VAS. Radiographic evaluation included CT, MRI, and x-rays. The results were analyzed using the Student t-test.
Results: The two groups were similar with respect to demographic and surgical characteristics. At an average follow-up of 62.1 months, 71 patients were completely reviewed. Mean ODI, RMDQ and VAS scores didn't show statistically significant differences. Fusion rate was similar between the two groups (97% in PLIF group, 95% in PLF group). Major complications occurred in 5 of 71 patients reviewed (7%): one in the PLIF group (3.6%), four in the PLF group (9.3%). Pseudarthrosis occurred in one case in the PLIF group (3,6%) and in two cases in PLF group (4.6%).
Conclusions: In our series, there does not appear to be a clear advantage of posterior lumbar interbody fusion (PLIF) over posterolateral fusion (PLF) in terms of clinical and radiological outcome for treatment of adult low grade isthmic spondylolisthesis.
The technique of posterior lumbar interbody fusion allows decompression of the spinal canal and interbody fusion through one posterior incision. A number of techniques exist to achieve additional posterior stability. The literature reports wide variation in outcomes for these different techniques. We assessed retrospectively the clinical and radiological outcome of posterior lumbar interbody fusion (PLIF) supplemented with an instrumented postero-lateral fusion (IPLF) using a pedicle screw system. Between July 1987 and April 1997, 60 patients underwent PLIF + IPLF. Clinical outcome was measured with physical examination in the outpatient setting and a patient questionnaire (patient satisfaction, analgesic use, return to work, Oswestry Disability Index). Radiological outcome was assessed with serial radiographs. If doubt existed regarding fixation, flexion/extension radiographs and plain tomograms were performed. The mean age was 44 years (range 19–69 years). The average follow-up was 5.3 years (range 1–10 years). Eighty percent of patients returned sufficiently completed questionnaires; 83% of these patients rated their outcome as good or excellent. Fifty percent of patients were able to return to full-time employment. All patients showed radiographic evidence of stable fixation. Four patients sustained a neurological complication, three of which resolved completely. The combination of PLIF with IPLF demonstrates clinical success, a stable circumferential fixation and a low complication rate.
Key words Posterior lumbar ¶interbody fusion; Instrumented ¶postero-lateral fusion; Surgical ¶technique; Clinical outcome; Radiological outcome
We investigated the clinical and radiological advantages of unilateral laminectomy in posterior lumbar interbody fusion (PLIF) procedure comparing with bilateral laminectomy, under the same procedural condition including bilateral instrumentation and insertion of two cages, in patients
with degenerative lumbar disease with unilateral leg symptoms.
We retrospectively reviewed 124 consecutive cases of PLIF via unilateral or bilateral approach between January 2006 and April 2010. In 80 cases (bilateral group), two cages were inserted via bilateral laminectomy, and in 44 cases (unilateral group), via unilateral laminectomy. The average
follow-up duration was 29.5 months. The clinical outcomes were evaluated with the Visual Analogue Scale (VAS) and the Oswestry disability index (ODI). The fusion rates and disc space heights were determined by dynamic standing radiographs and/or computed tomography. Operative times, intra-operative and post-operative blood losses and hospitalization periods were also evaluated.
In clinical evaluation, the VAS and ODI scores showed excellent outcomes in both groups. There were no significant differences in term of fusion rate, but the perioperative blood loss and the operative time of the unilateral group were lower than that of the bilateral group.
Unilateral laminectomy can minimize the operative time and perioperative blood loss in PLIF procedure. However, the different preoperative
disc height between two groups is a limitation of this study. Despite this limitation, solid fusion and satisfactory symptomatic improvement could be achieved uniquely by our surgical method. This surgical method can be an alternative surgical technique in patients with unilateral leg pain.
Posterior lumbar interbody fusion; Iatrogenic root injury; Unilateral approach; Unilateral leg symptoms
Transpedicular screw fixation has some disadvantages such as postoperative back pain through wide muscle dissection, long operative time, and cephalad adjacent segmental degeneration (ASD). The purposes of this study are investigation and comparison of radiological and clinical results between interspinous fusion device (IFD) and pedicle screw.
From Jan. 2008 to Aug. 2009, 40 patients underwent spinal fusion with IFD combined with posterior lumbar interbody fusion (PLIF). In same study period, 36 patients underwent spinal fusion with pedicle screw fixation as control group. Dynamic lateral radiographs, visual analogue scale (VAS), and Korean version of the Oswestry disability index (K-ODI) scores were evaluated in both groups.
The lumbar spine diseases in the IFD group were as followings; spinal stenosis in 26, degenerative spondylolisthesis in 12, and intervertebral disc herniation in 2. The mean follow up period was 14.24 months (range; 12 to 22 months) in the IFD group and 18.3 months (range; 12 to 28 months) in pedicle screw group. The mean VAS scores was preoperatively 7.16±2.1 and 8.03±2.3 in the IFD and pedicle screw groups, respectively, and improved postoperatively to 1.3±2.9 and 1.2±3.2 in 1-year follow ups (p<0.05). The K-ODI was decreased significantly in an equal amount in both groups one year postoperatively (p<0.05). The statistics revealed a higher incidence of ASD in pedicle screw group than the IFD group (p=0.029).
Posterior IFD has several advantages over the pedicle screw fixation in terms of skin incision, muscle dissection and short operative time and less intraoperative estimated blood loss. The IFD with PLIF may be a favorable technique to replace the pedicle screw fixation in selective case.
Degenerative; Fusion device; Interspinous; Lumbar disease; Posterior; Adjacent segmental degeneration
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.
AxiaLIF; axial presacral fusion; interbody; outcomes; two-level fusion
To describe the clinical outcomes and complications in a consecutive series of extreme lateral interbody fusion cases.
Retrospective cohort review of 97 consecutive patients from three centers with minimum 6-month follow-up (mean 12 months). Functional status was evaluated by preoperative and last follow-up Oswestry Disability Index score. Leg and back pain were evaluated by visual analog scales. Complications were recorded and permanent complications and neurological impairment was actively investigated at last follow-up.
No permanent neurological impairment, vascular or visceral injuries were observed. Transient neurological symptoms presented in 7% of cases, all resolved within 1 month from surgery. Transient thigh discomfort was observed in 9%. Clinical success was recorded in 92% of cases.
Extreme lateral interbody fusion is a safe and effective technique for anterior interbody fusion.
XLIF; Extreme lateral interbody fusion; Anterior lumbar interbody fusion; Spinal fusion; Outcomes; Complications
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.
Degenerative spine; lumbar spine fusion; minimally invasive transforaminal fusion
This study sought to determine the outcomes of posterior lumbar interbody fusion (PLIF), via a unilateral approach, in selected patients who presented with unilateral leg pain and segmental instability of the lumbar spine. Patients with a single level of a herniated disc disease in the lumbar spine, unilateral leg pain, chronic disabling lower back pain (LBP), and a failed conservative treatment, were considered for the procedure. A total of 41 patients underwent a single-level PLIF using two PEEK™ (Poly-Ether-Ether-Ketone) cages filled with iliac bone, via a unilateral approach. The patients comprised 21 women and 20 men with a mean age of 41 years (range: 22 to 63 years). Two cages were inserted using a unilateral medial facetectomy and a partial hemilaminectomy. At follow-up, the outcomes were assessed using the Prolo Scale. The success of the fusion was determined by dynamic lumbar radiography and/or computerized tomography scanning. All the patients safely underwent surgery without severe complications. During a mean follow-up period of 26 months, 1 patient underwent percutaneous pedicle screw fixation due to persistent LBP. A posterior displacement of the cage was found in one patient. At the last follow up, 90% of the patients demonstrated satisfactory results. An osseous fusion was present in 85% of the patients. A PLIF, via a unilateral approach, enables a solid union with satisfactory clinical results. This preserves part of the posterior elements of the lumbar spine in selected patients with single level instability and unilateral leg pain.
Posterior lumbar interbody fusion (PLIF); unilateral approach; instability
The recommended surgical options for postoperative wound infections after instrumented spine surgery include a wide debridement and irrigation with antibiotics. In most cases, implant removal is not recommended for a solid fusion. However, there are few reports on the treatment choices for persistent postoperative wound infections following a posterior lumbar interbody fusion (PLIF) using cages. This paper reviewed ten patients referred to our department, who underwent revision surgery for a postoperative, deep infection after a PLIF with cages. The surgery included an anterior radical debridement and interbody fusion with removal of all implants. The clinical and laboratory results, including a bacteriologic study for the causative organism and the radiological changes, were analyzed. All patients complained of persistent severe back pain after the primary surgery. MRSA was the main organism found in these patients (five cases). Complete bony fusion was obtained in nine patients (90%). In one patient, back pain and radiating pain prevented him from returning to his original work. Despite the anterior interbody fusion with an autogenous iliac bone graft, all cases had a complete collapse of the intervertebral disc space, without a dislodgement or collapse of the graft bone. The mean loss of the height and lordosis in the involved segment was 12.7 mm (range 4–46 mm) and 5.6° (range 0–15°), respectively. Anterior radical debridement with the removal of all implants would be an effective way to manage patients with postoperative spondylitis after a PLIF using cages.
Spondylitis; Posterior lumbar interbody fusion; Cage
We retrospectively evaluated the clinical and radiological outcomes of posterior lumbar interbody fusion (PLIF) with using a unilateral single cage and a local morselized bone graft.
Fifty three patients who underwent PLIF with a unilateral single cage filled with local morselized bone graft were enrolled in this study. The average follow-up duration was 31.1 months. The clinical outcomes were evaluated with using the visual analogue scale (VAS) at the pre-operative period, at 1 year post-operation and at the last follow-up, the Oswestry Disability Index, the Prolo scale and the Kim & Kim criteria at the last follow-up; the radiological outcomes were evaluated according to the change of bone bridging, the radiolucency, the instablity and the disc height.
For the clinical evaluation, the VAS pain index, the Oswestry Disability Index, the Prolo scale and the Kim & Kim criteria showed excellent outcomes. For the the radiological evaluation, 52 cases showed complete bone union at the last follow-up. Regarding the complications, only 1 patient had cage breakage during follow-up.
PLIF using a unilateral single cage filled with a local morselized bone graft has the advantages of a shorter operation time, less blood loss and a shorter hospital stay, as compared with the PLIF using bilateral cages, for treating degenerative lumbar spine disease. This technique also provides excellent outcomes according to the clinical and radiological evaluation.
Spinal fusion; Posterior lumbar interbody fusion; Unilateral single cage; Local morselized graft
Surgical treatment of lumbosacral foraminal stenosis requires an understanding of the anatomy of the lumbosacral area in individual patients. Unilateral facetectomy has been used to completely decompress entrapment of the L5 nerve root, followed in some patients by posterior lumbar interbody fusion (PLIF) with stand-alone cages.
We assessed 34 patients with lumbosacral foraminal stenosis who were treated with unilateral facetectomy and PLIF using stand-alone cages in our center from January 2004 to September 2007. All the patients underwent follow-up X-rays, including a dynamic view, at 3, 6, 12, 24 months, and computed tomography (CT) at 24 months postoperatively. Clinical outcomes were analyzed with the mean numeric rating scale (NRS), Oswestry Disability Index (ODI) and Odom's criteria. Radiological outcomes were assessed with change of disc height, defined as the average of anterior, middle, and posterior height in plain X-rays. In addition, lumbosacral fusion was also assessed with dynamic X-ray and CT.
Mean NRS score, which was 9.29 prior to surgery, was 1.5 at 18 months after surgery. The decrease in NRS was statistically significant. Excellent and good groups with regard to Odom's criteria were 31 cases (91%) and three cases (9%) were fair. Pre-operative mean ODI of 28.4 decreased to 14.2 at post-operative 24 months. In 30 patients, a bone bridge on CT scan was identified. The change in disc height was 8.11 mm, 10.02 mm and 9.63 mm preoperatively, immediate postoperatively and at 24 months after surgery, respectively.
In the treatment of lumbosacral foraminal stenosis, unilateral facetectomy and interbody fusion using expandable stand-alone cages may be considered as one treatment option to maintain post-operative alignment and to obtain satisfactory clinical outcomes.
Expandable cage; Foraminal stenosis; Lumbosacral spine
We randomised a total of 94 patients with long-standing moderate lumbar spinal stenosis (LSS) into a surgical group and a non-operative group, with 50 and 44 patients, respectively. The operative treatment comprised undercutting laminectomy of stenotic segments, augmented with transpedicular-instrumented fusion in suspected lumbar instability. The primary outcome was the Oswestry disability index (ODI), and the other main outcomes included assessments of leg and back pain and self-reported walking ability, all based on questionnaire data from 85 patients at the 6-year follow-up. At the 6-year follow-up, the mean difference in ODI in favour of surgery was 9.5 (95% confidence interval 0.9–18.1, P-value for global difference 0.006), whereas the intensity of leg or back pain did not differ between the two treatment groups any longer. Walking ability did not differ between the treatment groups at any time. Decompressive surgery of LSS provided modest but consistent improvement in functional ability, surpassing that obtained after non-operative measures.
Spinal stenosis; Surgical treatment; Non-operative treatment; Randomised controlled trial
This study is to compare the therapeutic effect of posterior lumbar interbody fusion (PLIF) and transforaminal lumbar interbody fusion (TLIF) with pedicle screw fixation on treatment in adult degenerative spondylolisthesis. A retrospective analysis of 187 patients to compare the complications and associated predictive factors of the two techniques of one level lumbar fusion. Ninety-one had PLIF with two cages and pedicle fixation (group 1), and ninety-six had TLIF with one cage and pedicle fixation (group 2). The two groups had similar age and sex distribution, and level of pain. Inclusion criteria and outcome measurements were identical in both groups. The two groups were operated on with autograft and cage with pedicle fixation. Before surgery and at the 2-year follow-up, pain (VAS) and functional disability (JOA) were quantified. The results showed there were no intraoperative deaths in our study. In the end 176 cases had 2-year follow-up while 11 cases were lost to follow-up. The follow-up rate was 93.4% (85/91) in the PLIF group and 94.8% (91/96) in the TLIF group. All patients had bone fusion, and there were no cases of cage extrusion. The pain index improved from 7.08 ± 1.13 to 2.84 ± 0.89 in PLIF patients and improved from 7.18 ± 1.09 to 2.84 ± 0.91 in TLIF patients (P < 0.001). There were 42 cases of excellent, 29 cases of good, 11 cases of general, and 3 cases of poor results in PLIF group. There were 46 cases of excellent, 31 case of good, 12 case of general, and 2 cases of poor results in TLIF group. The JOA score in all patients was 84.1% of good or excellent (83.5% in PLIF and 84.6% in TLIF, P > 0.05). The average preoperative slip was 30.1 ± 7.2% in PLIF group while in the TLIF it was 31.4 ± 8.3%. Immediately post operatively it was reduced to 7.3 ± 2.1% and 7.4 ± 2.7% and at last F/U it was 8.1 ± 2.8% and 8.2 ± 2.6%, respectively. The average of reduction rate was 75.2 ± 6.4% in PLIF and 75.4 ± 6.2 in TLIF on the initial post operatively X-ray, and 72.6 ± 5.2% and 72.4 ± 5.4% on the follow-up. The percentage rate, reduction rate and lost of reduction rate between the two groups was similar (P > 0.05). The average pre operative disk and foramen height in the PLIF group improved from 6.8 ± 2.3 and 14.2 ± 1.7 preoperatively to 11.6 ± 1.5 and 18.7 ± 1.8 post operatively, respectively. At last follow up there was minimal lost of correction down to 11.24 ± 1.2 and 18.1 ± 1.8, respectively. Similarly in the TLIF group, pre operative disk and foramen height were improved from 6.7 ± 1.7 and 14.1 ± 1.8 to 11.4 ± 1.6 and 18.5 ± 1.6 immediately post operative. At last follow up minimal lost of correction was noted with average disc height of 11.3 ± 1.4 and 18.2 ± 1.7. Both techniques achieve statistical significance in restoration of disc and foraminal (P < 0.01); however, there was no statistical difference between the two techniques. In conclusion, interbody fusion with either a PLIF technique or a TLIF technique provides good outcomes in the treatment of adult degenerative spondylolisthesis. The TLIF procedure is simpler and is as safe and effective as the PLIF technique.
Spondyolisthesis; Interverterbral fusion; Internal fixation
A retrospective study.
To comparatively investigated the rate of the adjacent segment degeneration and the clinical outcomes in patients with spondylolytic spondylolisthesis, spinal stenosis or degenerative spondylolisthesis.
Overview of Literature
There have been few studies reported on the adjacent segment degeneration following posterior lumbar interbody fusion(PLIF). Many risk factors for the adjacent segment degeneration following PLIF have been proposed. The range of decompression has been presented as one of the risk factors, yet controversial.
This study enrolled sixty-three patients who had been treated with single-level PLIF and who were followed up for more than two years. The patients were divided into 3 groups based on the preoperative diagnosis. We analyzed the difference between the preoperative and postoperative intervertebral disc heights of the superior adjacent segments. The incidence rates of instability and the clinical outcomes were comparatively analyzed between each group.
The average age of the patients was 55.8 years in the spondylolytic spondylolisthesis group, 65.9 years in the degenerative spondylolisthesis group and 60.4 years in the spinal stenosis group. The average follow-up period was 44 months, 43 months and 42 months, respectively. At the last follow-up, compared to the preoperative period, the intervertebral disc height decreased in all three groups. A statistically significant decrease (p < 0.01) was observed only in the spondylolytic spondylolisthesis group and no significant difference was observed between each group (p = 0.41). The incidence rate of instability and the clinical outcome were not significantly different between each group.
Spondylolytic spondylolisthesis with total laminectomy and single-level PLIF showed no significant difference in the superior adjacent segment degeneration and instability, and the clinical outcome as compared to that of partial laminectomy with single-level PLIF for treating degenerative spondylolisthesis or spinal stenosis.
Spondylolytic spondylolisthesis; Adjacent segment disease; Posterior lumbar interbody fusion
This retrospective study was performed to evaluate the clinical and radiological results of anterior lumbar interbody fusion (ALIF) using two different stand-alone cages in the treatment of lumbar intervertebral foraminal stenosis (IFS).
A total of 28 patients who underwent ALIF at L5-S1 using stand-alone cage were studied [Stabilis® (Stryker, Kalamazoo, MI, USA); 13, SynFix-LR® (Synthes Bettlach, Switzerland); 15]. Mean follow-up period was 27.3 ± 4.9 months. Visual analogue pain scale (VAS) and Oswestry disability index (ODI) were assessed. Radiologically, the change of disc height, intervertebral foraminal (IVF) height and width at the operated segment were measured, and fusion status was defined.
Final mean VAS (back and leg) and ODI scores were significantly decreased from preoperative values (5.6 ± 2.3 → 2.3 ± 2.2, 6.3 ± 3.2 → 1.6 ± 1.6, and 53.7 ± 18.6 → 28.3 ± 13.1, respectively), which were not different between the two devices groups. In Stabilis® group, postoperative immediately increased disc and IVF heights (10.09 ± 4.15 mm → 14.99 ± 1.73 mm, 13.00 ± 2.44 mm → 16.28 ± 2.23 mm, respectively) were gradually decreased, and finally returned to preoperative value (11.29 ± 1.67 mm, 13.59 ± 2.01 mm, respectively). In SynFix-LR® group, immediately increased disc and IVF heights (9.60 ± 2.82 mm → 15.61 ± 0.62 mm, 14.01 ± 2.53 mm → 21.27 ± 1.93 mm, respectively) were maintained until the last follow up (13.72 ± 1.21 mm, 17.87 ± 2.02 mm, respectively). The changes of IVF width of each group was minimal pre- and postoperatively. Solid arthrodesis was observed in 11 patients in Stabilis group (11/13, 84.6%) and 13 in SynFix-LR® group (13/15, 86.7%).
ALIF using stand-alone cage could assure good clinical results in the treatment of symptomatic lumbar IFS in the mid-term follow up. A degree of subsidence at the operated segment was different depending on the device type, which was higher in Stabilis® group.
Anterior approach; Lumbar interbody fusion; Lumbar foraminal stenosis; Stand-alone cage
Treatment outcome of low back pain (LBP) is associated with inter-individual variations in pain relief and functional disability. Genetic variants of catechol-O-methyltransferase (COMT) gene have previously been shown to be associated with pain sensitivity and pain medication. This study examines the association between COMT polymorphisms and 7–11 year change in Oswestry Disability Index (ODI) and Visual Analog Score (VAS) for LBP as clinical outcome variables in patients treated with surgical instrumented lumbar fusion or cognitive intervention and exercise.
93 unrelated patients with chronic LBP for duration of >1 year and lumbar disc degeneration (LDD) were treated with lumbar fusion (N = 60) or cognitive therapy and exercises (N = 33). Standardised questionnaires assessing the ODI, VAS LBP, psychological factors and use of analgesics, were answered by patients both at baseline and at 7–11 years follow-up. Four SNPs in the COMT gene were successfully genotyped. Single marker as well as haplotype association with change in ODI and VAS LBP, were analyzed using Haploview, linear regression and R-package Haplostats. P-values were not formally corrected for multiple testing as this was an explorative study.
Association analysis of individual SNPs adjusted for covariates revealed association of rs4633 and rs4680 with post treatment improvement in VAS LBP (p = 0.02, mean difference (β) = 13.5 and p = 0.02, β = 14.2 respectively). SNPs, rs4633 and rs4680 were found to be genotypically similar and in strong linkage disequilibrium (LD). A significant association was found with covariates, analgesics (p = 0.001, β = 18.6); anxiety and depression (p = 0.008, β = 15.4) and age (p = 0.03, mean difference per year (β) = 0.7) at follow-up. There was a tendency for better improvement among heterozygous patients compared to the homozygous. No association was observed for the analysis of the common haplotypes, these SNPs were situated on.
Results suggest an influence of genetic variants of COMT gene in describing the variation in pain after treatment for low back pain. Replication in large samples with testing for other pain related genes is warranted.
Abundant data are available for direct anterior/posterior spine fusion (APF) and some for transforaminal lumbar interbody fusion (TLIF), but only few studies from one institution compares the two techniques. One-hundred and thirty-three patients were retrospectively analyzed, 68 having APF and 65 having TLIF. All patients had symptomatic disc degeneration of the lumbar spine. Only those with one or two-level surgeries were included. Clinical chart and radiologic reviews were done, fusion solidity assessed, and functional outcomes determined by pre- and postoperative SF-36 and postoperative Oswestry Disability Index (ODI), and a satisfaction questionnaire. The minimum follow-up was 24 months. The mean operating room time and hospital length of stay were less in the TLIF group. The blood loss was slightly less in the TLIF group (409 vs. 480 cc.). Intra-operative complications were higher in the APF group, mostly due to vein lacerations in the anterior retroperitoneal approach. Postoperative complications were higher in the TLIF group due to graft material extruding against the nerve root or wound drainage. The pseudarthrosis rate was statistically equal (APF 17.6% and TLIF 23.1%) and was higher than most published reports. Significant improvements were noted in both groups for the SF-36 questionnaires. The mean ODI scores at follow-up were 33.5 for the APF and 39.5 for the TLIF group. The patient satisfaction rate was equal for the two groups.
Symptomatic lumbar disc degeneration; Anterior–posterior fusion; Transforaminal lumbar interbody fusion
Both the paraspinal muscle sparing approach and percutaneous screw fixation are less traumatic procedures in comparison with the conventional midline approach. These techniques have been used with the goal of reducing muscle injury. The purpose of this study was to evaluate and to compare the safety and efficacy of the paraspinal muscle sparing technique and percutaneous screw fixation for the treatment of L5-S1 spondylolisthesis.
Twenty patients who had undergone posterior lumbar interbody fusion (PLIF) at the L5-S1 segment for spondylolisthesis were prospectively studied. They were divided into two groups by screw fixation technique (Group I : paraspinal muscle sparing approach and Group II: percutaneous screw fixation). Clinical outcomes were assessed by Low Back Outcome Score (LBOS) and Visual Analogue Scale (VAS) for back and leg pain at different times after surgery. In addition, modified MacNab's grading criteria were used to assess subjective patients' outcomes 6 months after surgery. Postoperative midline surgical scarring, intraoperative blood loss, mean operation time, and procedure-related complications were analyzed.
Excellent or good results were observed in all patients in both groups 6 months after surgery. Patients in both groups showed marked improvement in terms of LBOSs all over time intervals. Postoperative midline surgical scarring and intraoperative blood loss were lower in Group II compared to Group I although these differences were not statistically significant. Low back pain (LBP) and leg pain in both groups also showed significant improvement when compared to preoperative scores. However, at 7 days and 1 month after surgery, patients in Group II had significantly better LBP scores compared to Group I.
In terms of LBP during the early postoperative period, patients who underwent percutaneous screw fixation showed better results compared to ones who underwent screw fixation via the paraspinal muscle sparing approach. Our results indicate that the percutaneous screw fixation procedure is the preferable minimally invasive technique for reducing LBP associated with L5-S1 spondylolisthesis.
Spondylolisthesis; Paraspinal muscle sparing approach; Percutaneous screw fixation; Back pain