“Delta fixation” was developed to treat low-grade L5 isthmic spondylolisthesis. It involves placement of pedicle screws into L5 and from S1 through the L5/S1 disc into L5 (Fig.1). A biomechanical comparison to standard Posterior Lumbar Interbody Fusion (PLIF) with two anterior cages and pedicle screws in L5 and S1 was made. Eight fresh frozen human specimens were instrumented with both fixations and tested. Delta fixation was significantly more stable in resisting rotation. It requires less manipulation of the nerve roots and spares the cost of the fusion cages. Our objective is to compare the stability of Delta versus PLIF fixation in the treatment of low grade isthmic spondylolisthesis. Delta fixation provides superior initial stability, and therefore is an acceptable alternative to PLIF for the treatment of low grade isthmic spondylolisthesis of L5-S1. Symptomatic low-grade isthmic spondylolisthesis of L5 is often managed with PLIF. This procedure requires extensive manipulation of the cauda equine, posterior resection of the disc and the placement of two inter-body cages as spacers in addition to pedicle screws in L5 and S1. Delta Fixation has been developed to provide stable fixation with less nerve root manipulation and without the use of inter-body cages. It is therefore a safer alternative method of fixation that spares the additional cost of the fusion cages. When comparing Delta fixation to PLIF fixation the only statistically significant difference was found in axial rotation. Delta fixation had 2.05 degrees less ROM and 0.90 degrees less NZ compared to PLIF fixation with P values of 0.0052 and 0.0104 respectively. This demonstrates that the delta fixation is more stable than PLIF fixation. Eight fresh frozen human spines were used. Matched pairs were created and block randomization used to create two groups: PLIF fixation and Delta fixation groups. The specimens were instrumented with a grade II spondylolisthesis of L5-S1, tested, and then re-instrumented with the alternative fixation and tested again. Vertical displacement, axial rotation, flexion– extension and side bending were tested using an MTS machine. Please contact author for tables and/or diagrams

Introduction The management of severe pain associated with progressive adult scoliosis remains a challenging problem. Radicular symptoms are often caused by bony foraminal stenosis and significant global and segmental imbalance may exist in both the sagittal and coronal planes. The patients are often elderly and have intercurrent medical conditions. The use of disc space distraction, pedicle screw instrumentation and posterior lumbar interbody fusion (PLIF) with Insert and Rotate prostheses has been shown to be effective in the correction of sagittal plane deformity (. 1. ). The current study examines the safety, clinical and radiological efficacy of this technique in the management of adult multilevel scoliosis. Methods A prospective single cohort observational study of 15 consecutive patients with a degenerative scoliosis of 20 degrees or greater managed using an Insert and Rotate PLIF technique between October 2000 and July 2003. The minimum follow-up was 2 years. Clinical outcome measures included VAS pain score, SF-12, LBOS and Patient Satisfaction survey. Pre- and post-operative measures of radiological sagittal and coronal deformity were manually obtained. Wilcoxon signed-ranks test and Spearman’s non parametric test for correlation were used with significance set at 0.05. Results The median age was 72 years (range: 56–80). Male: female ratio was 6:9. PLIF was carried out at 2 levels in 7 patients, 3–5 levels in 8 patients. Median blood loss was 1100mls for 2 level patients and 2550mls for 3–5 level patients. Operating time was 345mins and 545mins in the 2 and 3–5 level cases respectively. Median pre-operative scoliosis was 31degrees (range: 20–65) and post-operatively measured 14degrees (range: 0–30, p=0.001). Median pre-op VAS of 53 reduced to 20 (p=0.003). LBOS improved from 24 to 37 (p=0.004). A correlation was found between the amount of pre-operative coronal plane deformity and the post-operative VAS (r=0.6, p=0.003). 13 of the 15 patients considered the procedure was worthwhile and that they would have it again under similar circumstances. Early post-operative complications included electrolyte/fluid disturbance in 2 patients, 2 cardiac arrhythmias, one DVT/PE and 2 returns to the O.R. for pain caused by a misplaced pedicle screw or bone graft. One patient developed a progressive scoliosis above the fusion and one a pathological wedge compression fracture. 4 patients required late surgery including 2 who had been fused down to L5 and required extension of their fusion to the sacrum for pain associated with an L5/S1 foraminal stenosis and one who developed a painful non-union. Discussion PLIF with an Insert and Rotate technique following disc space distraction for severe and progressive adult scoliotic deformity is technically difficult and can be associated with significant peri-operative morbidity. Nevertheless, the reported satisfaction rates by the patients in this small series are encouraging and the procedure appears to have achieved substantial correction of global and segmental deformity in both the coronal and sagittal planes. Whether this will be beneficial in the long term requires further study

Introduction. Recently various type of spinal instrumentation was applied, and they are essential in modern spinal fusion surgery. Whereas several authors reported increased possibility of complication and degeneration on adjacent segment. We tried PLIF without instrumentation with box type intervertebral cages. Method. Forty-one cases of degenerative lumbar diseases were treated by PLIF with carbon cages without spinal instrumentation. There were 17 males and 24 females, and age averaged 71.4 years. Thirty-two cases were degenerative spondylolisthesis, five were spinal stenosis, and four were disc herniation. Single PLIF was performed on forty cases, and double segment in one, with additional decompression on other segment in twenty. Bilateral facet joint were preserved to avoid lateral instability. Two pieces of cage were inserted with local bone graft. Post-op. follow-up period were 12 to 24 months, 15 months on average. Result. JOA score (29 pts on full mark) averaged 12.7 pts before the operation and was 25.4 pts at the F/U. Recovery ratio averaged 77.9%. Clinical result was excellent in 27 with more than 75% of R/R. One case showed symptomatic non-union, and additional instrumentation was applied after one year. Thirty-three cases (80%) showed solid bone union after one year, and eight cases were classified as non-union. Whereas early cage migration with vertebral collapse was seen on fourteen, and union with collapse was seen in eight. These conditions showed less clinical outcome. Conclusion. Stand alone PLIF resulted in good clinical results with box type cages. Stand alone PLIF is less invasive method and minimize chance of complication. Conflicts of interest. None. Sources of funding. None

Object: To study the incidence, etiology and management of patients with neuralgia following Posterior Lumbar Interbody Fusion (PLIF). Design: A prospective study of 216 patients undergoing PLIF surgery from March 1996 to August 2003. Subjects: 16 of the 225 patients (7.1%) undergoing PLIF surgery developed new leg pain following surgery. Results In all patients, the distribution of the postoperative pain was different than the pre-operative pain. Nerve swelling with relative stenosis was the most common cause (9/16), followed by pedicular screw misplacement (2/16), nerve anomaly (2/16), loose posterior arch (2/16), and graft subsidence (1/16). Nine patients with nerve swelling complained of pain with no neurological findings. One responded to a root block and 6 to re-exploration and further decompression. The patients with misplaced screws woke up from surgery with pain and neurology. The pain responded to removal of screws in both. Two patients with loose posterior arches complained of leg pain while lying down only. These symptoms disappeared after excision of the arches. In 2 patients conjoint roots were found intra-operatively. Both developed post operative pain, which settled down in one. In one patient subsidence of an iliac graft caused pain a few months following surgery and did not respond to further decompression. Discussion: The overall incidence of post PLIF neuralgia was 7.1%, however by removing the whole facet, as performed in the last 122 patients, the incidence reduced from 9.7% (first 103 patients) to 4.9%. Based on our data we propose a classification system for Post PLIF Neuralgia, and a management plan. Using both, 11 of the 16 patients reported their leg pain disappeared, leaving only 5 patients with residual leg pain (< 3%). Key-stones in avoiding post PLIF neuralgia are generous decompression of the nerve roots, especially the lateral recess above the disc, total facetectomy and removal of graft pieces before closure

Object: To study the incidence, etiology and management of patients with neuralgia following Posterior Lumbar Interbody Fusion (PLIF). Design: A prospective study of 85 patients undergoing PLIF surgery from March 1996 to March 2001. Subjects: Seven of the 85 patients undergoing PLIF surgery developed new leg pain between three days and five months following surgery. Results: The incidence of neuralgia was 8%. In all the patients the post-surgical neuralgia was in a new distribution. MRI examination ruled out misplaced pedicle screws in all cases, but was otherwise unhelpful. One patient developed neuralgia five months post-operatively due to collapse of the cortico-cancellous graft and secondary foraminal narrowing. This was not relieved following surgical decompression. Four patients had neuralgia caused by relative stenosis of the exiting nerve (3) or the traversing nerve (1) which started between three days and two weeks after surgery. The pain was relieved in all four following surgical decompression. One patient had leg pain when lying down; standing and sitting relieved this. A loose lamina was found on exploring the wound. Her pain settled after surgery. One patient developed a spondylolisthesis at the level below a L4/5 PLIF four months after surgery. Her pain was eased by stabilization of the lower segment. Conclusions: MRI scans are not very helpful in these cases. Early exploration is recommended and gave good results in six of our seven cases

Introduction: The nonunion rate is higher and loss of reduction is common after reduction and fusion for the higher grades of spondylolisthesis. This is due to fusion bone base deficiency and lack of anterior column support, and can be addressed by supplementing the posterolateral fusion with a posterior lumbar interbody fusion (PLIF). Materials: All patients had a single disc level degenerative or spondylolytic slip exceeding 25%. Laminectomy and instrumented reduction (VSP or TSRH) was performed. 86 patients underwent posterolateral fusion and 82 underwent the same procedure plus a PLIF (done by tightly impacting bone chips into the disc cavity after a very aggressive discectomy). No fusion cages were used. Results: Presented as No-PLIF vs. PLIF. Age: 56 vs. 52 years. Male/Female: 14:72 vs. 15:67. Cases with pars fx: 44% vs. 56%. Level of slip (L3-4, L4-5, L5-S1): 9, 59, 18 vs. 4, 60, 18. Iatrogenic neurological injury: none vs. none. Deep infection: 1 vs. none. Nonunion: 9.3% vs. 2.4%. Broken screws: 6 vs. 2. Degree of slip (pre-op to post-op to 2 years): 34% to 11% to 20% vs. 38% to 4% to 8%. Patients that lost reduction: 67% vs. 18%. Disc height gained at 2 years: −0.2 mm vs. 2.3 mm. Subjective back pain score: 3.5 vs. 2.0. Greenough LBOS score: 54 vs. 62. Patients very satisfied: 43% vs. 60%. Cases with adjacent level slip: 4 vs. 4. Discussion: Spondylolisthesis is commonly treated with a spinal fusion. The goal of surgery is to eliminate motion between the unstable segments, and mechanically it is preferable that the vertebrae fuse in as near anatomic position as possible. It has been shown that the fusion rate decreases with higher degrees of slip, with the spondylolytic types, and with severely degenerated discs. Pedicle screw instrumentation can increase the fusion rate. Reduction of the slip can often be achieved, but it is common to lose the reduction over the course of 1–2 years if only posterolateral fusion is done. Adding an interbody fusion cage can help restore the disc height and widen the intervertebral foramen, but increases complexity, cost, and may actually decrease bone contact area and compression forces. We have found that in grade II and worse slips, pedicle screw fixation alone is not strong enough to maintain reduction of either vertebral alignment or disc height. Adding a chip PLIF appears safe and effective in increasing the union rate and the disc height, and in maintaining reduction in grade II spondylolisthesis. Clinical results are better, the infection rate is not higher. In our hands, there have been no neurological injuries. This study also raises questions about the role and need for interbody fusion cages

Purposes: To evaluate the effectiveness of Posterior Lumbar Interbody Fusion (PLIF) surgery in resolving back and back related leg pain and its effect on quality of life. Methods: Two hundred and twenty six patients who met the inclusion criteria of degenerative disc disease, spondylolisthesis, disc herniation and postlaminec-tomy/postdiscectomy syndrome unresolved by conservative therapy were entered into the study. Patients were assessed using a self-administered questionnaire containing the Oswestry disability index (ODI) for back pain related disability, visual analogue scales (VAS) for back and leg pain severity (0 = none, 10 = worst imaginable pain) and the SF-36 general health questionnaire. Outcomes were assessed preoperatively and at a minimum of 2 years follow-up. Statistical significance was tested using a paired t-test after confirming normality of the data. Results: Of the 226 patients,182 (99 females, 83 males; mean age at treatment, 45.3 years; age range 15 – 67 years) returned follow-up questionnaires (81% response). The mean duration of follow-up was 26.4 months (range 24 – 60 months). The ODI showed a statistically and clinically significant improvement between baseline (52.1) and follow-up (29.5), (22.6(17.8 to 27.5); P= 0.000). This represents a 43% improvement in functional ability. There was a statistically and clinically significant improvement between VAS back pain scores at baseline (7.7) and follow-up (3.9), (3.8 (3.1 to 4.4); P = 0.000 ). This represents a reduction of 49%. Similarly VAS leg pain at baseline (6.6) and follow-up (3.2) ,(3.4 (2.7 to 4.2); P = 0.000) showed a reduction of 52% which was also statistically and clinically significant. All dimensions of the SF-36 except role physical showed a statistically and clinically significant improvement. Conclusion: The results show that in our series, there is a statistically and clinically significant improvement in pain, functional ability and quality of life after PLIF surgery in patients with chronic back and leg pain unresolved by conservative therapy

Purposes: To evaluate the effectiveness of Posterior Lumbar Interbody Fusion (PLIF) surgery in resolving back and back related leg pain and its effect on quality of life. Methods: Two hundred and twenty six patients who met the inclusion criteria of degenerative disc disease, spondylolisthesis, disc herniation and postlaminec-tomy/postdiscectomy syndrome unresolved by conservative therapy were entered into the study. Patients were assessed using a self-administered questionnaire containing the Oswestry disability index (ODI) for back pain related disability, visual analogue scales (VAS) for back and leg pain severity (0 = none, 10 = worst imaginable pain) and the SF-36 general health questionnaire. Outcomes were assessed preoperatively and at a minimum of 2 years follow-up. Statistical significance was tested using a paired t-test after confirming normality of the data. Results: Of the 226 patients,182 (99 females, 83 males; mean age at treatment, 45.3 years; age range 15 – 67 years) returned follow-up questionnaires (81% response). The mean duration of follow-up was 26.4 months (range 24 – 60 months). The ODI showed a statistically and clinically significant improvement between baseline (52.1) and follow-up (29.5), (22.6(17.8 to 27.5); P= 0.000). This represents a 43% improvement in functional ability. There was a statistically and clinically significant improvement between VAS back pain scores at baseline (7.7) and follow-up (3.9), (3.8 (3.1 to 4.4); P = 0.000 ). This represents a reduction of 49%. Similarly VAS leg pain at baseline (6.6) and follow-up (3.2) ,(3.4 (2.7 to 4.2); P = 0.000) showed a reduction of 52% which was also statistically and clinically significant. All dimensions of the SF-36 except role physical showed a statistically and clinically significant improvement. Conclusion: The results show that in our series, there is a statistically and clinically significant improvement in pain, functional ability and quality of life after PLIF surgery in patients with chronic back and leg pain unresolved by conservative therapy

INTRODUCTION: Since Briggs and Milligan first described posterior lumbar interbody fusion (PLIF) in 1944, it has been a controversial technique. However, modern pedicle screw instrumentation and the use of intervertebral spreaders and implants have provided a powerful technique for the restoration of spinal balance in degenerative deformity. This study assesses the functional outcomes and safety in a series of patients undergoing complete reduction and posterior interbody fusion (PLIF) of lumbosacral spondylolisthesis with interbody fusion spacers implanted using an Insert and Rotate technique. METHODS: A prospective, non-randomised, observational study of pre- and post-operative data, in a series of 35 patients with lumbosacral degenerative or isthmic spondylolisthesis, between April 2001 and June 2002. All patients underwent decompressive laminectomy followed by complete reduction of the spondylolisthetic deformity with the aid of intervertebral disc space spreaders and pedicle screw instrumentation. Wedge shaped spacers made from Carbon Fiber, Titanium mesh or PEEK plastic were then inserted on their sides and rotated 90 degrees to support the vertebral end plates prior to placing bone graft beside them, within the disc space. Outcomes were measured using the Low Back Outcome Score (LBOS), SF-12, visual analogue pain scores (VAS) and patient satisfaction survey. RESULTS: Of the 35 patients, 24 had degenerative spondylolisthesis and 11 were isthmic in type. 26 were Meyerding Grade I; seven were Grade II; one was Grade III and one was Grade IV. The indications for surgery included relief of foraminal stenosis in 26 and likely post-operative instability in 24. Average time of last follow-up was 7.4 ± 3.0 months. Data are available on 34 of the 35 patients at three months and 29 at six to twelve months (83%). Mean pre-operative VAS and LBOS were 5.1 ± 2.5 and 26.5 ± 16.9, respectively. Mean scores at last follow-up were 2.2 ± 2.4 and 45.6 ± 14.6 (p< 0.01 for both measures). At last follow-up, 30 of the 35 patients or 88.2% described their outcome as good or excellent. One patient considered himself worse. 91% said the procedure had been worthwhile but only 79% said they would have it again under similar circumstances. There were no deaths. There were no interbody implant/PLIF related problems but five intraoperative problems related to pedicle screw placement with one screw loosening during slip reduction, requiring replacement. Post-operatively, three patients developed an ileus. One patient developed a probable wound infection with high fever which settled on antibiotics. DISCUSSION: This series represents a recent subset of a much larger total series managed with this technique for symptoms associated with spondylolisthetic deformity (187 patients to date). The author has previously reported to the society on the clinical results of the technique but without the benefit of prospective pre-operative data. This smaller series appears to confirm the results of the earlier studies and suggests that PLIF using an Insert and Rotate technique can yield satisfactory clinical outcomes with high patient satisfaction and low levels of complications

Purpose: We report on the midterm clinical results in a retrospective series of 157 patients who have undergone PLIF with the Varilift expandable and lordotic cages, mostly stand alone. Material & methods: 157 consecutive patients, 80 men and 76 women, with a mean age of 44 (19 to 72); Single level procedure in 123 patients, 2 levels in 34 patients. Preoperative symptoms included chronic low back pain and/or sciatica for more than 6 months with failure of conservative treatment including epidural steroids. Primary surgical indications were degenerative disc disease (n = 76), spondylolisthesis (n = 33), failed back syndromes (n = 43 patients). Posterior fixation was added in 21 of the spondylolisthesis, 2 multi-level fusions and 3 other patients due to a previous wide laminectomies and a resultant instability. Surgical technique consisted of minimal bilateral laminotomy preserving the midline ligamentous structures and the conservation of most of the facets. Results: Follow ranged from 12 to 60 months. There were a 89.2% satisfactory results, 10 fair and 7 poor results, of which 2 required revision. Neither revision was due to implant failure. Fusion was deemed solid in 150 from the 157 patients, 7 showed an asymtomatic radiolucency around the cage, but without motion on bending films. 3 other patients needed a posterior fixation removal after one year. Of the 128 patients working pre-op, post-op 92 patients returned to their previous job, 18 returned to a less strenuous position and 18 patients did not return to work. No patient’s symptoms worsened. As major complications, we noted 3 cases of foot drop who had partial (1) or complete recovery (2), and one cases of unilateral thrombosis of the retinum central artery. there were no cage breakage or migration of the implants. Segmental lordosis, measured on the fused discs at the last follow up showed a mean angle of lordosis of 6.9o (4.8° on L4–L5, 8° on L5–S1). Conclusion: The VariLiftTM Cage confirms by its medium term result the stand alone feature in the appropriate indications. This PLIF technique resulted in a greater than 90% fusion rate, with a minimal of complications, good pain relief, and early recovery. No failure of the material was noted. The major advantages of this device are its intrinsic stability, the big inner volume for bone graft, the promoting of lordosis and the overall size saving that authorize a minimal invasive procedure

Introduction: Since Briggs and Milligan first described posterior lumbar interbody fusion (PLIF) in 1944, it has been a controversial technique. However, modern pedicle screw instrumentation and the use of intervertebral spreaders and implants have provided a powerful technique for the restoration of spinal balance in degenerative deformity. This study assesses the functional outcomes and safety in a series of patients undergoing complete reduction and posterior interbody fusion (PLIF) of lumbosacral spondylolisthesis with interbody fusion spacers implanted using an Insert and Rotate technique. Methods: A prospective, non-randomized, observational study of pre- and post-operative data, in a series of 35 patients with lumbosacral degenerative or isthmic spondylolisthesis, between April 2001and June 2002. All patients underwent decompressive laminectomy followed by complete reduction of the spondylolisthetic deformity with the aid of intervertebral disc space spreaders and pedicle screw instrumentation. Wedge shaped spacers made from Carbon Fiber, Titanium mesh or PEEK plastic were then inserted on their sides and rotated 90 degrees to support the vertebral end plates prior to placing bone graft beside them, within the disc space. Outcomes were measured using the Low Back Outcome Score (LBOS), SF-12, visual analogue pain scores (VAS) and patient satisfaction survey. Results: Of the 35 patients, 24 had degenerative spondylolisthesis and 11 were isthmic in type. 26 were Meyerding Grade I; seven were Grade II; one was Grade III and one was Grade IV. The indications for surgery included relief of foraminal stenosis in 26 and likely post operative instability in 24. Average time of last follow-up was 7.4 ± 3.0 months. Data is available on 34 of the 35 patients at 3 months and 29 at six to twelve months (83%). Mean pre-operative VAS and LBOS were 5.1 ± 2.5 and 26.5 ± 16.9, respectively. Mean scores at last follow up were 2.2 ± 2.4 and 45.6 ± 14.6 (p< 0.01 for both measures). At last follow-up, 30 of the 35 patients or 88.2% described their outcome as good or excellent. One patient considered himself worse. 91% said the procedure had been worthwhile but only 79% said they would have it again under similar circumstances. There were no deaths. There were no interbody implant / PLIF related problems but five intraoperative problems related to pedicle screw placement with one screw loosening during slip reduction, requiring replacement. Post-operatively, 3 patients developed an ileus. One patient developed a probable wound infection with high fever which settled on antibiotics. Discussion: This series represents a recent subset of a much larger total series managed with this technique for symptoms associated with spondylolisthetic deformity (187 patients to date). The author has previously reported to the society on the clinical results of the technique but without the benefit of prospective pre-operative data. This smaller series appears to confirm the results of the earlier studies and suggests that PLIF using an Insert and Rotate technique can yield satisfactory clinical outcomes with high patient satisfaction and low levels of complications

We evaluated the maturation of grafted bone in cases of successful fusion after a one- or two-level posterior lumbar interbody fusion (PLIF) using interbody carbon cages. We carried out a five-year prospective longitudinal radiological evaluation of patients using plain radiographs and CT scans. One year after surgery, 117 patients with an early successful fusion were selected for inclusion in the study. Radiological evaluation of interbody bone fusion was graded on a 4-point scale. The mean grades of all radiological and CT assessments increased in the five years after surgery, and differences compared to the previous time interval were statistically significant for three or four years after surgery. Because the grafted bone continues to mature for three years after surgery, the success of a fusion should not be assessed until at least three years have elapsed. There were no significant differences in the longitudinal patterns of grafted bone maturity between iliac bone and local bone. However, iliac bone grafting may remodel faster than local bone.

Recurrence of back or leg pain after discectomy is a well-recognised problem with an incidence of up to 28%. Once conservative measures have failed, several surgical options are available and have been tried with varying degrees of success. In this study, 42 patients with recurrent symptoms after discectomy underwent less invasive posterior lumbar interbody fusion (LI-PLIF). Clinical outcome was measured using the Oswestry Disability Index (ODI), Short Form 36 (SF-36) questionnaires and visual analogue scales for back (VAS-BP) and leg pain (VAS-LP). There was a statistically significant improvement in all outcome measures (p < 0.001). The debate around which procedure is the most effective for these patients remains controversial.

Our results show that LI-PLIF is as effective as any other surgical procedure. However, given that it is less invasive, we feel that it should be considered as the preferred option.

We evaluated the impact of lumbar instrumented circumferential fusion on the development of adjacent level vertebral compression fractures (VCFs). Instrumented posterior lumbar interbody fusion (PLIF) has become a popular procedure for degenerative lumbar spine disease. The immediate rigidity produced by PLIF may cause more stress and lead to greater risk of adjacent VCFs. However, few studies have investigated the relationship between PLIF and the development of subsequent adjacent level VCFs. . Between January 2005 and December 2009, a total of 1936 patients were enrolled. Of these 224 patients had a new VCF and the incidence was statistically analysed with other covariants. In total 150 (11.1%) of 1348 patients developed new VCFs with PLIF, with 108 (72%) cases at adjacent segment. Of 588 patients, 74 (12.5%) developed new subsequent VCFs with conventional posterolateral fusion (PLF), with 37 (50%) patients at an adjacent level. Short-segment fusion, female and age older than 65 years also increased the development of new adjacent VCFs in patients undergoing PLIF. In the osteoporotic patient, more rigid fusion and a higher stress gradient after PLIF will cause a higher adjacent VCF rate. Cite this article: Bone Joint J 2015;97-B:1411–16

Introduction and Objective. Posterior and transforaminal lumbar interbody fusion (PLIF, TLIF) represent the most popular techniques in performing an interbody fusion amongst spine surgeons. Pseudarthrosis, cage migration, subsidence or infection can occur, with subsequent failed surgery, persistent pain and patient’ bad quality of life. The goal of revision fusion surgery is to correct any previous technical errors avoiding surgical complications. The most safe and effective way is to choose a naive approach to the disc. Therefore, the anterior approach represents a suitable technique as a salvage operation. The aim of this study is to underline the technical advantages of the anterior retroperitoneal approach as a salvage procedure in failed PLIF/TLIF analyzing a series of 32 consecutive patients. Materials and Methods. We performed a retrospective analysis of patients’ data in patients who underwent ALIF as a salvage procedure after failed PLIF/TLIF between April 2014 to December 2019. We recorded all peri-operative data. In all patients the index level was exposed with a minimally invasive anterior retroperitoneal approach. Results. Thirty-two patients (average age: 46.4 years, median age 46.5, ranging from 21 to 74 years hold- 16 male and 16 female) underwent salvage ALIF procedure after failed PLIF/TLIF were included in the study. A minimally invasive anterior retroperitoneal approach to the lumbar spine was performed in all patients. In 6 cases (18.7%) (2 infection and 4 pseudarthrosis after stand-alone IF) only anterior revision surgery was performed. A posterior approach was necessary in 26 cases (81.3%). In most of cases (26/32, 81%) the posterior instrumentation was overpowered by the anterior cage without a previous revision. Three (9%) intraoperative minor complications after anterior approach were recorded: 1 dural tear, 1 ALIF cage subsidence and 1 small peritoneal tear. None vascular injuries occurred. Most of patients (90.6%) experienced an improvement of their clinical condition and at the last follow-up no mechanical complication occurred. Conclusions. According to our results, we can suggest that a favourable clinical outcome can firstly depend from technical reasons an then from radiological results. The removal of the mobilized cage, the accurate endplate and disc space preparation and the cage implant eliminate the primary source of pain reducing significantly the axial pain, helping to realise an optimal bony surface for fusion and enhancing primary stability. The powerful disc distraction given by the anterior approach allows inserting large and lordotic cages improving the optimal segmental lordosis restoration

The clinical success of posterior lumbar interbody fusion (PLIF) may be limited by pseudarthrosis, defined as the absence of solid fusion 1 year after surgery. Currently, CT is used to diagnose pseudarthrosis but is not able to be conclusive earlier than 1 year after surgery. No non-invasive technique is available to reliably assess bone graft incorporation in the early phase after PLIF. Positron Emission Tomography (PET) is a nuclear imaging modality that is able to identify changes at the cellular and molecular level in an early stage, well before manifestation of anatomical changes. PET/CT with the bone seeking tracer . 18. F-fluoride allows localization and quantification of bone metabolism. This study investigates whether an . 18. F-fluoride PET/CT scan early after PLIF is able to predict the fusion status at 1 year postoperative on CT. Twenty patients after PLIF were enrolled after written informed consent. At 6 weeks and at 1 year after PLIF, intravenous injection of . 18. F-fluoride was followed by a static scan at 60 minutes (Philips, Gemini TF PET/CT). Processing of images resulted in a bone metabolism parameter i.e. standardized uptake value (SUV). This parameter was determined for 3 regions of interest (ROIs): the intervertebral disc space (IDS) and the upper and lower endplate (UE and LE, respectively) of the operated segment. Interbody fusion was scored on a diagnostic CT scan made 1 year postoperatively and was defined as the amount of complete bony bridges between vertebrae, i.e 0, 1 or 2. Based on these scores, patients were divided in either the pseudarthrosis group (score 0) or the fusion group (scores 1 and 2). Differences between groups were analyzed using the independent samples Mann-Whitney U-test. Ten patients were classified as pseudarthrosis (0 bridges: n=10) and 10 patients as fused (1 bridge: n=5, 2 bridges: n=5). Patients in the pseudarthrosis group showed significantly lower bone metabolism values in the IDS on the 6 weeks PET/CT scan compared to patients in the fusion group (SUV. IDS,6w. 13.3±5.62 for pseudarthrosis and 22.6±6.42 for the fusion group, p=0.003), whereas values at the endplates were similar (SUV. UE,6w. 20.3±5.85 for pseudarthrosis and 21.6±4.24 for the fusion group, p=0.282). Furthermore, only in the pseudarthrosis group, bone metabolism in the IDS was significantly lower than at the endplates (p=0.006). In the fusion group, bone metabolism in the IDS and at the endplates was similar (p=0.470). The PET/CT scan at 1 year postoperative showed that in the pseudarthrosis group, bone metabolism of the IDS remained lower compared to the endplates (SUV. IDS,1y. 13.2±4.37, SUV. UE,1y. 16.4±5.33, p=0.004), while in the fusion group, IDS and endplate bone metabolism was similar (SUV. IDS,1y. 13.6±2.91, SUV. UE,1y. 14.4±3.14, p=0.397). This study shows that low bone metabolism values in the IDS of the operated segment as seen on . 18. F-fluoride PET/CT 6 weeks after PLIF, is related to development of pseudarthrosis 1 year postoperatively. These results suggest that . 18. F-fluoride PET/CT might be an early diagnostic tool to identify patients prone to develop pseudarthrosis after PLIF

Posterior lumber interbody fusion (PLIF) has the theoretical advantage of optimising foraminal decompression, improving sagittal alignment and providing a more consistent fusion mass in adult patients with isthmic spondylolisthesis (IS) compared to posterolateral fusion (PLF). Previous studies with only short-term follow-up have not shown a difference between fusion techniques. An observational cohort study was performed of a single surgeon's patients treating IS over a ten year period (52 patients), using either PLF (21 pts) or PLIF (31pts). Preoperative and 12-month data were collected prospectively, and long-term follow-up was by mailed questionnaire. Preoperative patient characteristics between the two groups were not significantly different. Average follow-up was 7 years, 10 months, and 81% of questionnaires were returned. Outcome measures were Roland Morris Disability Questionnaire (RMDQ), Low Back Outcome Score (LBOS), SF-12v2 and SF-6D R2. The SF-6D R2 is a “whole of health” measure. PLIF provided better short- and long-term results than PLF. The PLIF group had significantly better LBOS scores in the long term, and non-significantly better RMDQ scores in the long term. As measured by RMDQ Minimum Clinically Important Difference (MCID) short term set at 4, RMDQ MCID set at 8, the LBOS MCID set at 7.5 points and by SF-12v2 physical component score (PCS), PLIF patients performed better than PLF patients. When analysing single level fusions alone, the difference is more pronounced, with PCS, mental component scores and SF-6D R2 all being significantly better in the PLIF group rather than the PLF group. This paper strongly supports the use of PLIF to obtain equivalent or superior clinical outcomes when compared to PLF for spinal fusion for lumbar isthmic spondylolisthesis. The results of this study are the first to report to such long-term follow-up comparing these two procedures

Posterior lumbar interbody fusion (PLIF) is indicated for many patients with pain and/or instability of the lumbar spine. We performed 36 PLIF procedures using the patient’s lumbar spinous process and laminae, which were inserted as a bone graft between two vertebral bodies without using a cage. The mean lumbar lordosis and mean disc height to vertebral body ratio were restored and preserved after surgery. There were no serious complications. These results suggest that this procedure is safe and effective

The April 2013 Spine Roundup. 360 . looks at: smuggling spinal implants; local bone graft and PLIF; predicting disability with slipped discs; mortality and spinal surgery; spondyloarthropathy; brachytherapy; and fibrin mesh and BMP

Introduction: Discectomy for herniation of the nucleus pulposus is an effective procedure when conservative treatment has failed. However, a number of patients rapidly progress to symptomatic instability after discectomy. Those most likely to develop instability have central and multi-regional herniations. Therefore, primary posterior lumbar interbody fusion (PLIF) may be a better option than discectomy alone in this group. This paper presents the clinical and radiological outcome of a consecutive group of such patients treated in one centre by PLIF, but recognises that newer technologies may make such destructive spinal surgery unnecessary in the future. Methods: Between June 1997 and December 2000, PLIF for central disc herniation presenting with acute, subacute and chronic back and leg pain, with or without neurological loss, using Diapason pedicle screw instrumentation and Ogival PEEK (Polyether-ether-ketone) Interbody Fusion cages was performed on 41 patients. Eight patients presented acutely with cauda equina symptoms and 33 patients had sub-acute or chronic symptoms. Formal clinic follow-up was continued for at least two years post-surgery and the final outcome at 2 to 5 years after operation was assessed using the Low Back Outcome Score (LBOS). Two independent orthopaedic surgeons assessed the radiological evidence of fusion on X-rays taken at least two years after surgery. Results: 39 of the 41 patients completed the LBOS questionnaire (95%). One patient had died from an unrelated cause and the other could not be contacted having moved away. 34 (87%) of these had an excellent or good outcome according to the LBOS criteria. However, every patient who returned the questionnaire stated that they would undergo the operation again if guaranteed the same surgical result and all would recommend it to a friend for similar trouble. Four patients (9.7%) were dissatisfied with the process of care they experienced. Analysis of radiographs taken between two and four years post-operatively revealed that spinal fusion (as defined by the Brantigan and Steffee criteria) was present in 38 cases (92.7%). None of the patients with a non-union radiologically had a poor outcome. Conclusions: Post-discectomy instability causing disabling low back and leg pain is more likely to occur in patients with an incompetent annulus than those with a largely intact annulus. The patients in this series all had good evidence on MRI of complete (pan-annular) failure. The decision to perform an acute single level PLIF was taken after discussion with the patients, presenting them with the option of having only a central discectomy and a later fusion if needed or of dealing with the problem at one operation. The outcomes described in this study show that this condition is a good indication for PLIF. However, newer technologies such as disc arthroplasty may be a better option for this group of patients in the future