Purpose of the study: Experimentally, posterolateral fusion only allows incomplete control of flexion/extension, rotation and lateral inclination. This defect of posterolateral fusion is most marked with there is a wide anterior gap. For certain authors, this situation justifies use of intersomatic arthrodesis. The purpose of this work was to evaluate, within a spinal segment immobilized by posterolateral fusion, the changes observed in disc height and the possible clinical and radiographic impact of a change in disc height. Material and methods: This was a retrospective analysis of a consecutive series of patients who underwent posterolateral fusion from January 1999 through December 2003 performed in addition to radicular release for degenerative spondylolisthesis were included. Functional symptoms were noted using: VAS, Beaujon function scale, Beaujon self-administered questionnaire, satisfaction scale, GHA28 anxiety/depression scale, and SF36 quality of life questionnaire. Spineview® was applied at the olisthesic level (disc height, listhesis, anglulation), at adjacent levels, for pelvic parameters, sagittal tilt, and vertebral motion on stress views. We searched for a correlation between the consequences of changes in these variables was and the functional outcome as well as the quality of the fusion. The effect of variations in the following preoperative variables was studied with multivariate analysis: disc height, intervetebral angulaion, listhesis, vertebral motion, sagittal balance, use of osteosynthesis or not. Results: Forty patients were reviewed with a mean follow-up of 38 months (range 15–70 months). Decreased disc height at the olithesic level was associated with local kyphosis. The level above tended towards lordosis while the level below towards kyphosis. These variations had no effect on the final functional outcome. Discussion: No formal argument could be found in the literature favoring the use of intersomatic arthrodesis to complete posterolateral fusion for the treatment of degenerative spondylisthesis. Disc height is lost after isolated posterolateral fusion with a risk of local kyphosis and persistent intervertebral motion, but these effects do not appear to influence the functional outcome nor the rate of fusion. More than disc height, it would appear that sagittal balance should be preserved to improve functional outcome. Conclusion: This study enabled us to observe, as is reported in the literature, decreased disc height after posterolateral fusion for degenerative spondylolisthesis. However, there appears to be no correlation between this decreased disc height and the functional outcome. More than disc height, sagittal balance appears to be the determining factor

Introduction Circumferential fusion has become a common procedure in lumbar spinal fusion, both as a primary and salvage procedure. However, the claimed advantages of circumferential fusion over conventional posterolateral fusion lack scientific documentation. The aim of the present study was to analyse the long-term outcome; functional disability, pain and general health of circumferential lumbar fusion in comparison to instrumented posterolateral lumbar fusion. Methods From April 1996 to November 1999 a total of 148 patients with severe chronic low back pain were randomly selected for either posterolateral lumbar fusion (titanium Cotrel-Dubousset) or circumferential lumbar fusion (instrumented posterolateral fusion with anterior intervertebral support by a Brantigan cage). The primary outcome measure was the Dallas Pain Questionnaire (DPQ). The secondary outcome measures were, the Oswestry Disability Index, the SF-36 instrument and the Low Back Pain Rating Scale. All measures assessed the end-point outcomes at 5–9 years postoperatively. Results The available follow-up rate was 93%. The circumferential group showed a significantly better improvement (p< 0.05) in comparison to the posterolateral group with respect to all four DPQ categories: daily activities, work/leisure, anxiety/depression and social interest. The Oswestry Disability Index supported these results (p< 0.01) in the circumferential group where as no significant difference was found with respect to mental health compared to the posterolateral group. The circumferential group showed significantly less back pain (p< 0.05) in comparison to the posterolateral group. No significant difference was found regarding leg pain. Discussion Circumferential lumbar fusion demands more extensive operative resources compared to posterolateral lumbar fusion. However, 5–9 years after surgery the circumferentially fused patients had a significantly improved outcome compared to posterolateral fusion alone. These new results underline the superiority of circumferential fusion in the complex pathology of the lumbar spine and are strongly supported in all validated questionnaires

Spondylolytic spondylolisthesis is one of the common causes of mechanical low back pain in adults. Conservative treatment of such cases, particularly for the low grade slips, remains the mainstay of management. When patients’ symptoms are marked and not responsive to conservative therapy, the surgical option can be considered. Up to the time of writing this abstract [January 2003], arthrodesis of the affected motion segment with or without instrumentation is the standard surgical option for treating mechanical low back pain. Results of different types of arthrodesis for treating such condition had been reported in literature, including posterior fusion, posterolateral fusion, and posterior and anterior interbody fusion. Between 1993 and 1998, seventy- five adult patients with grade I or II lytic spondylolisthesis were treated by in situ posterolateral fusion and segmental instrumentation using the Oswestry Pedicle Screw System, with or without extended Gill’s procedure. The indications for surgical intervention in these cases were significant reduction in the quality of life with persistent low back pain and/or leg pain after a minimum of six months conservative therapy. Confirmatory imaging studies consistent with the clinical data should also be obtained before deciding the surgical option. The average operative time was 2.5 hours [range 2–4 hours). The average blood loss was 850 mls (range 300–2300 mls). After an average follow-up of 60.7 months (range 24–95 months) clinical results were excellent and good in 92%, and radiological union was achieved in 94% of patients. Complications included 2 cases with superficial wound infection, one case with deep wound infection, and four of the patients went to non-union. In conclusion, with a careful patient selection, patients with instrumental insitu posterolateral fusion gained a satisfactory clinical and radiological outcome and the results were maintained for an adequate postoperative period

The aim of the study was to assess the results of posterolateral fusion (PLF) of L5/S1 level spondylolisthesis. Materials 19 children (5 girls, 14 boys) aged 10–18 years (average 14) were treated surgically PLF in years 1985–2002. 18 cases before surgery were classified as grade I and II, 1 as grade III according to Meyerding classification. Long lasted low back pain, progression of the slippage was the main indication for operative treatment. In every case suspension in prone position were applied before surgery. Methods The Denis clinical classification was used to evaluate results. On radiographs we evaluated the verticalisation of the sacrum, lordosis at lumbosacral area by drawing Whitman-Ferguson, Boxall, Fernand-Fox angles. The mobility of the fused segment was estimated on the functional radiographs. Results In clinical evaluation improvement was achieved in 18 cases, in 1 no improvement was achieved. In radiological estimation the slippage decreased in 17 cases varying from 1 grade to 39 grades (average 10 grades). In 1 case no improvment was achieved and in 1 the slippage increased (8 grades). The value of Fernand-Fox angle increased from 1 grade to 35 grades in 16 cases; in 1 no improvement was achieved and in 2 cases the value decreased. In every patient the posterior segmental union was achieved. On MRI scans disc degeneration was observed in 2 patients. Conlusions Our results confirm the existence of the remodeling process in the lumbo-sacral area of the spine. We think that PLF in painful grade I and II spondylolisthesis is adequate method of treatment

Study Design. Single surgeon prospective cohort with radiological follow-up. Background. Anjarwalla et al. have shown that the addition of posterior pedicle supplementation without posterolateral fusion during an ALIF procedure significantly increases the rate of interbody fusion when using a carbon fibre / PEEK cage packed with autogenous iliac crest graft. Stand alone ALIF cages which utilise screws passing through the interbody cage and into the vertebral bodies were designed to obviate the need for a posterior procedure by increasing the anterior construct stability and fusion rate. Objective. To assess the effect of posterior pedicle screw supplementation without posterolateral fusion on the fusion rate of ALIF when using anterior cage and screw constructs. Method. Between 2003 and 2008 91 patients underwent ALIF procedure under a single surgeon for low back pain associated with degenerative disc disease or lytic spondylolisthesis. Routine CT was performed at around 1 to 2 years follow up to ensure union prior to discharge. It was noted that there was a significant number of locked pseudathroses, especially in 2 level cases, and in 2006 the surgeon started to perform simultaneous supplementary posterior pedicle screw stabilisation without posterolateral fusion in the majority of cases. Results. Of the 91 patients, 77 (85%) had CT follow up at mean 21 months. 45 patients had anterior surgery alone (26 single level and 19 two level) and 32 had front back surgery (15 single level and 17 two level). Pseudarthrosis was seen in 16 patients (36%) of the anterior alone group and 2 (6%) of the front back group. In the anterior alone group, pseudarthosis occurred in 6 / 26 (23%) patients with single level surgery and 10 /19 (53%) of those with two level surgery. In this last group, the pseudarthosis occurred in the upper fusion level in five patients and at both fusion levels in other five. Conclusion. Posterior pedicle screw supplementation without posterolateral fusion improves the fusion rate of ALIF when using anterior cage and screw constructs. We would recommend supplementary posterior fixation especially in cases where more than one level is being operated

Aims: To find a long-term effect of posterolateral fusion for isthmic spondylolysis and spondylolisthesis on lumbar spine. Methods: A posterolateral fusion was performed on 56 patients (30 females, 26 males) with an average age of 16 (range 11 to 20) years. A clinical and MRI examination was performed on these patients on average 18 years later (range 11 to 25 years). The size of the spinal canal were assessed. Disc space, degeneration and protrusions were evaluated. Bone marrow changes (Modic I & II), facet joint degeneration and the state of the spinal muscles were assessed. Results: In MR images, none of the patients had lumbar spinal stenosis. In contrast, the spinal canal was wide in the level spondylolysis and spondylolisthesis. Narrowing of the neural foramina was noted in 13 (23%) patients. This was associated usually in severe slip (> 50%) and was noted always at the L5-S1 level. Of the studied 332 intervertebral discs 56 (17%) were speckled and 57 (17%) were black and 76 (23%) narrowed. Most commonly speckled/black and narrowed disc was found in the two lowest lumbar levels. Only one patient, 41-year-old female, had prolapse. Modic I and II changes were noted in 7 (2%) and 9 (3%) intervertebral disc levels, respectively. Degenerative-like facet joint hypertrophy was noted in 47 (48%) of the studied levels. Of the patients, seven (12%) had muscular atrophy. Conclusions: Stenosis of neural foramina may be associated to severe spondyolisthesis. Degenerative changes were found most commonly found in the level of the spondylolysis and spondylolisthesis and above fusion level. Bone marrow changes associated with disc degeneration were rare

Introduction: Spondylolytic spondylolisthesis is a not uncommon cause of back pain in adults. The initial management, especially for the low grade slips, is usually conservative. When this fails or is deemed inadequate surgical options are considered. The principles of surgical treatment involve a fusion of the painful segment or segments (usually with instrumentation), with an associated decompression if there is radicular leg pain. Some authors also propose a simultaneous reduction of the slip. Most reports in the literature on adults have a short follow-up. Materials and method: This paper reports the results of surgery from two centres carried out between 1993 and 1998 on 75 adult patients using the same indication for surgery and the same surgical technique. The indication for surgery was a significant reduction in the quality of life with persistent low back and/or leg pain after conservative treatment for a minimum of six months. The surgery involved an in situ posterolateral fusion with pedicular fixation (Oswestry system) with a simultaneous decompression for radicular involvement. The average operating time was 2.5 hours (range 2–4) and the average blood loss 850 mls (range 300–2300). The mean follow-up was 61 months (range 24 to 95). Results and conclusion: A solid fusion was considered to be present in 71 of the 75 cases (95%) using the Lenke and Bridwell (1997) criteria for radiological union. Seventy-two of the 75 cases (96%) had a very satisfactory clinical outcome (Ricciardi et al 1995). The complications were limited – two superficial wound infections and one deep wound infection which resolved after debridement of the wound. There were no neurological complications. The authors believe that with careful patient selection an instrumented in-situ posterolateral fusion is a safe and effective operation for symptomatic low grade slips providing good long term results

The purpose of the study is to evaluate the outcome of two methods: Posterolateral fusion and instrumentation versus posterolateral fusion, instrumentation and interbody fusion using clinical and radiological criteria in demographically similar groups. This is a prospective cohort study of sixty-four patients randomized to two therapeutic strategies (Level II study). Sixty-four patients were randomized to either instrumented posterolateral fusion (control) or combined instrumented posterolateral and interbody fusion (study) in one level degenerative disorders of the lumbar spine. Demographics of the groups were similar including age, gender and other variables. The demographics of the groups were similar for one level degenerative disorders—disc herniation, spondylolisthesis and spinal stenosis. The primary outcome was measured by the Oswestry Disability Index at two years. There was no statistically significant difference. Secondary outcomes (SF36, VAS, fusion rate, disc height maintenance, maintenance of deformity correction, adjacent segment degeneration) were statistically similar in both groups. In conclusion, no clinical advantage with interbody fusion versus posterolateral fusion alone. Analysis of the correlation between the pedicle shape and the spinal canal anatomy in scoliotic anatomic specimens. S. Parent1, H. Labelle, W. Skalli, J. de Guise,. 13175 Côte Ste-Catherine, Montréal, Québec H3T 1C5. The objective of the present study was to analyze the correlation between the pedicle shape and spinal canal anatomy in scoliotic specimens. Vertebral canal anatomy was evaluated in a series of thirty anatomic scoliotic specimens and compared to thirty normal specimens. Spinal canal enlargement inversely correlated with pedicle width modifications on the concavity of scoliotic curves. These findings suggest that changes in pedicle anatomy are secondary to local changes in spinal cord position. Recent studies have demonstrated the close relationship between the spinal cord and the pedicle on the concavity of the scoliotic curve of patients with scoliotic deformities. The hypothesis of the present study is that changes in spinal canal shape are related to spinal cord position and resulting bone remodeling. This study evaluated the characteristic changes of spinal canal shape in anatomic scoliotic specimens. Posterior elements morphology is closely related to the local spinal cord anatomy and its relationship with the bony architecture. The characteristic posterior element changes seen in scoliosis are likely the result of local bone remodeling. Spinal asymmetry was observed in scoliotic specimens when compared to normal specimens. Spinal canal was enlarged asymmetrically on the concavity of thoracic scoliotic curves (p < 0.01). Overall, canal surface was greater in scoliotic specimens when compared to normal specimens (p < 0.01). These changes were more important at the apex of the curve. Spinal canal characteristic shape was evaluated in thirty scoliotic anatomic specimens and thirty normal anatomic specimens using twelve parameters representing measures of right and left hemi-canal length, width or surface area. The 3-D coordinates of eight points taken at the periphery of each spinal canal were recorded. The results of this study support the hypothesis that spinal canal shape is modified by the spinal cord position and that posterior element changes seen in scoliosis are in part due to bone remodeling in response to local neural anatomy modifications. Funding: Fonds de Recherche en Santé du Québec

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

A subgroup of nine patients, five women and four men, who received lumbar disc prostheses in a segment adjacent to previous posterolateral instrumented fusions (one or two levels) is reviewed. Two patients underwent double-level disc replacement. The mean age was 46.1 years (33 to 62). All patients had marked flattening of the lumbar spine before the operation. One patient developed subsidence within two weeks of the procedure but went on to a satisfactory result. One patient with a double-level disc replacement needed another operation because of a missed far out lateral disc. On day five after the procedure, the top-level disc was removed, the level properly decompressed and the disc reinserted, with good results. The mean postoperative hospital stay was 3.9 days (3 to 8). Within a mean time of 32 days (21 to 42), all patients returned to their previous occupations. Follow-up ranged from 3 to 19 months. At the latest follow-up, four of the patients were satisfied and five were very satisfied. Disc replacement seems an ideal salvage procedure for junctional failure after previous fusions. The short-term clinical results are good

Due to well-known disadvantages of the autologous bone graft, many alternatives have been studied for a reliable spinal fusion. Herein, we aimed to investigate the effects of human recombinant epidermal growth factor (EGF) on posterolateral lumbar fusion in a rat model. 36 male SD rats underwent posterolateral fusion at L4-5 level. They were randomly assigned to 3 groups: Sham control group, Hydoxyapatite β-tricalcium phosphate (HA/β-TCP) group and HA/β-TCP + EGF group. Rats were euthanized at 8 weeks post-surgery. 6 rats from each group were selected for manual palpation examination, micro-computed tomography analysis and histologic analysis; and the rest was used for biomechanical analysis. Based on manual palpation, there was no fusion in the sham control group. Fusion rate was 33.3% in the HA/β-TCP group and 66.7% in the HA/β-TCP + EGF group (p=0.085). Micro-CT results revealed that new bone formation was higher in the HA/β-TCP + EGF group (BV/TV: 40% vs. 65%) (p=0.004). Histologically newly formed bone tissue was more pronounced in the EGF group and compacted and bridging bone spicules were observed. The median maximum bending moment values were 0.51 Nmm (0.42– 0.59), 0.73 Nmm (0.49– 0.88) and 0.91 Nmm (0.66– 1.03) in the sham control, HA/β-TCP and HA/β-TCP + EGF groups, respectively (p=0.013). The median stiffness values were 1.69 N/mm (1.12–2.18), 1.68 N/mm (1.13–2.74) and 3.10 N/mm (1.66–4.40) as in the previous order (p=0.087). This study demonstrates that EGF enhances posterolateral lumbar fusion in the rat model. EGF in combination with ceramic grafts increased the fusion rates

Background context

Fusion is a fundamental procedure in spine surgery. Although autogenous grafts have ideal bone graft characteristics, their use may remain limited due to various morbidities. Even though ceramic based synthetic bone grafts are used commonly at present, in order to enhance their efficacy, their combined use with other materials has been investigated. The use of carbon nanotubes (CNTs) together with synthetic bone grafts such as hydroxyapatite (HA) has contributed to positive developments in bone tissue engineering.

Purpose: B2A2-K-NS (B2A) is a synthetic receptor-targeted peptide that appears to amplify the biological response to rhBMP-2. In ectopic sites in vivo, B2A augments bony mineralization when combined with demineralized bone matrix. The purpose of this study was to determine if the synthetic peptide B2A2-K-NS coated on osteoconductive granules (B2A/G) enhances autograft fusion in a rabbit bilateral posterolateral spine fusion model.

Method: Sixty skeletally mature New Zealand White Rabbits weighing 4.5–5.5 kg were entered into the study (IACUC #0511251). A single-level, bilateral posterolateral intertransverse process fusion was performed at L4-L5 with autogenous bone or an osteoconductive granule containing several coating concentrations of B2A. Animals were euthanized at 6 weeks post surgery.

Results: Gross examination of the surrounding soft tissues and grafted area showed no adverse reactions to the osteoconductive granules with or without B2A. Radiographic fusion rates were similar to palpation fusion rates across all groups. When assessed by palpation, animals treated with 300 μg B2A/G had 80% fusion while those treated with 100 μg B2A/G (89%) and 50 μg B2A/G had 78% fusion. Animals receiving 0 μg B2A/G (granules only) had a fusion rate of 33% and autograft only animals had a fusion rate of 63%.

Conclusion: In this model the B2A/G composition appeared to function as a graft enhancer and be more efficacious than autograft alone in this model. B2A peptide has a unique mechanism of action in that although it interacts with receptors for BMP-2, the action is mediated only in the presence of BMP-2 or an osteoinductive event. In this model, the decorticated TP and/or autogenous bone may have provided the necessary signals for B2A. These results suggest that B2A/G should be further investigated to determine mechanistic effects and clinical applications

Introduction: Lumbar fusion is one of the most frequently recommended treatments in spinal surgery, whereas ALIF and PLF are discussed controversially. This prospective and consecutive study examined if complications and rehabilitation differed between patients with a degenerated lumbar spine, who had been treated with ALIF or PLF.

Methods: Between 04/2002 and 12/2005 clinical data of 39 patients, who were treated with ALIF, and of 296 patients, who received PLF, were submitted to the European Spine Register SSE Spine Tango. Complications and rehabilitation process were documented after a median follow-up time of 9 weeks (IQR 8–24 weeks). Analysis was performed with non-parametric tests. The study corresponds with an EBM-level 3.

Results: The median age of patients with ALIF was 56 years (IQR 37-66 yrs) vs. 64 yrs in the PLF group (IQR 54–72 yrs) with a male to female ratio 10:29 vs. 108:188.

Patients after ALIF and PLF had an even complication rate (5/39 vs. 26/296, p = 0,41). The types of complications in the ALIF group were less severe (sensory and motoric disturbance vs. implant failure and implant malposition). All five patients needing reintervention belonged to the PLF group. Three quarters of all patients underwent rehabilitation. The proportion of patients with outpatient rehabilitation was higher in the ALIF group (14/39 vs. 50/296 patients, p = 0,05).

Conclusions: Patients with degenerative lumbar spine disease have a less severe type of complications after ALIF than after PLF, whereas the complication rate is even. Concerning the higher proportion of patients with outpatient rehabilitation in the ALIF group, one has to consider their lower age compared with patients in the PLF group. Except for the severeness of complications and the proportion of outpatient rehabilitation one cannot conclude an advantage of either of the two surgical methods.

Introduction: Lumbar spine fusion is now an evidence based treatment principle of low back pain. However, much controversy still exists on the choice of surgical technique. Since the source of pain may be located in the intervertebral disc, a disc removal seems logical. Instrumented and non-instrumented fusion as well as PLIF have failed to restore lumbar lordosis.

Aim: The aim of the present study was to study fusion rates, functional outcome, lumbar lordosis and complications in a RCT design using radiolucent cages and titanium instrumentation.

Materials and methods: 148 patients were bloc randomised to either PLF (72) or ALIF + PLF (76) from April 1996 to February 2000. Inclusion criteria were disc degeneration or spondylolisthesis groups 1 and 2; Age> 20 years and < 65 years. Life quality was assessed pre-operatively, one and two years post-operatively by Dallas Pain Questionnaires and by Back and Leg Pain rating scales from 0 to 10.

Results and discussion: A preliminary follow-up at one year post-op of 56 patients in each group showed no difference in admission or blood loss (921/1008 ml) and peroperative morbidity, although the operation time was significantly longer in the ALIF+ group (mean 219/344 minutes). Sagittal lordosis was restored and maintained in the ALIF+ group (p< 0.01), in contrast to the PLF group. There was no difference in functional outcome. Average back pain lasting 14 days scored 4.5 in each group, and leg pain 3.2 in the ALIF+ group versus 4 in the PLF group (NS). The re-operation rate was significantly higher in PLF after both one and two years with 9% refusion versus no refusion in the ALIF+ group. Global patient satisfaction was equal in both groups: 78% versus 76% at one year and at two years 75% versus 80% in PLF and ALIF+ groups.

Conclusion: ALIF+ fusion demands higher operative resources compared to PLF, however ALIF+ restores lordosis and provides the highest union rate and significantly fewer reoperations. A cost/effectiveness analysis after long-term follow-up may also favour the ALIF+ treatment due to improved lordosis and perhaps less degeneration of adjacent motion segments.

Background. Posterolateral fusion (PLF) is a commonly accepted surgical procedure and overall the most common technique performed to obtain fusion in the lumbar spine. Harvesting autologous bone from the iliac crest is associated with increased operation time, blood loss, and chronic donor site pain. Allograft material has an insufficient osteoinductive potential. Bone marrow concentrate (BMC) could be an option how to promote allograft PLF healing. The purpose of the presented study was to investigate the validity of BMC addition to allografts in instrumented lumbar PLF surgery. Methods. The study was prospective, randomised, controlled and blinded. Eighty patients with degenerative disease of the lumbar spine underwent instrumented (S. 4. , Aesculap, Tuttlingen, Germany) lumbar or lumbosacral PLF. In forty cases, the PLF was done with spongious allograft chips alone (Group I). In another forty cases, spongious allograft chips were mixed with BMC (Group II), where the mesenchymal stem cell (MSCs) concentration was 1.74 × 10. 4. /L at average (range, 1.06–1.98 × 10. 4. /L). Patients were scheduled for anteroposterior and lateral radiographs at 12 and 24 months after the surgery and for CT scanning at 24 months after the surgery. Fusion status and the degree of mineralization of the fusion mass were evaluated separately by two radiologists blinded to patient group affiliation. Results. In Group I at 12 months, the bone graft mass was assessed in X-rays as fused in no case (0 %) and at 24 months in 4 cases (10 %). In Group II, 6 cases (15 %) achieved fusion at 12 months and 14 cases (35 %) at 24 months. The statistically significant difference between both groups was proven for complete fusion at 12 months (p = 0.041) and at 24 months (p = 0.011), too. CT scans showed that 16 cases (40 %) in Group I and 32 cases (80 %) in Group II had evidence of at least unilateral continuous bridging bone between neighboring vertebrae at 24 months (p < 0.05). We have confirmed the hypothesis that the autologous BMC together with the allograft is a better alternative for the PLF than the allograft alone. Conclusions. The use of autologous MSCs in form of the BMC in combination with allograft is an effective option how to enhance the PLF healing. Allograft by itself is not an effective material as a posterior onlay graft for the PLF in adult surgery

Introduction: Posterolateral intertransverse lumbar fusion is a commonly performed procedure for stabilization of the degenerated lumbar spine. A typical clinical scenario for which such fusions are used is the stabilization of a degenerative spondylolisthesis after decompression. In a recent large series reported in the literature, this type of fusion was noted to have a pseudarthrosis rate of up to 45% (Fischgrund, Spine 1997). Methods: A pilot study was designed to evaluate the safety and efficacy of osteoinductive protein-1 (OP-1, also known as recombinant human BMP-7) in lumbar posterolateral fusion. Thirty-six patients with the diagnosis of symptomatic spinal stenosis and single level degenerative spondylolisthesis in the lower lumbar spine (L3-S1) were enrolled. The patients were randomized to either the OP-1 group or the control group. The OP-1 group received 3.5 mg of OP-1 per side in a putty carrier. The control group received iliac crest autograft alone. Outcomes were measured clinically using the Oswestry score and radiographically using dynamic radiographs evaluated independently by two blinded radiologists using digital calipers. Patients were deemed a clinical success if they showed a > 20% improvement in Oswestry score and were deemed a radiographic success if they showed bridging bone and spinal stability on flexion/ extension films. Results: At twelve months, 18/21 (85.7%) patients in the OP-1 group and 8/11 (72.7%) patients in the autograft group were considered clinical successes, while 13/18(72.2%) of patients in the OP-1 group and 6/10 (60%) patients in the autograft group were considered radiographic successes. No adverse events related to the use of OP-1 were noted. Discussion: Despite the non-statistical number of patients enrolled in this pilot study, these preliminary results suggest that OP-1 appears to be a safe and effective replacement for iliac crest autograft in human posterolateral lumbar fusion. The OP-1 group had a higher radiographic fusion rate than the autograft group. This correlated well with the greater clinical success experienced by the OP-1 group, as measured by improvement in the Oswestry score. None of the previously reported device related complications related to the use of BMP’s in animal studies, such as exuberant bone growth with subsequent neural impingement, ectopic ossification, or spinal stenosis, were seen in the treatment group. Conclusion: OP-1 appears to be a safe and effective replacement for iliac crest autograft in human posterolateral lumbar fusion. The dose, 3.5mg per side, and the carrier, a biodegradable putty, appear to provide a safe and effective means of delivering the bone morphogenetic protein OP-1 to the human lumbar spine

INTRODUCTION: Posterolateral intertransverse lumbar fusion is a commonly performed procedure for stabilisation of the degenerated lumbar spine. A typical clinical scenario for which such fusions are used is the stabilisation of a degenerative spondylolisthesis after decompression. In a recent large series reported in the literature, this type of fusion was noted to have a pseudarthrosis rate of up to 45% (Fischgrund, Spine 1997). METHODS: A pilot study was designed to evaluate the safety and efficacy of osteoinductive protein-1 (OP-1, also known as recombinant human BMP-7) in lumbar posterolateral fusion. Thirty-six patients with the diagnosis of symptomatic spinal stenosis and single level degenerative spondylolisthesis in the lower lumbar spine (L3–S1) were enrolled. The patients were randomised to either the OP-1 group or the control group. The OP-1 group received 3.5 mg of OP-1 per side in a putty carrier. The control group received iliac crest autograft alone. Outcomes were measured clinically using the Oswestry score and radiographically using dynamic radiographs evaluated independently by two blinded radiologists using digital calipers. Patients were deemed a clinical success if they showed a > 20% improvement in Oswestry score and were deemed a radiographic success if they showed bridging bone and spinal stability on flexion/ extension films. RESULTS: At twelve months, 18/21 (85.7%) patients in the OP-1 group and 8/11 (72.7%) patients in the autograft group were considered clinical successes, while 13/18 (72.2%) of patients in the OP-1 group and 6/10 (60%) patients in the autograft group were considered radiographic successes. No adverse events related to the use of OP-1 were noted. DISCUSSION: Despite the non-statistical number of patients enrolled in this pilot study, these preliminary results suggest that OP-1 appears to be a safe and effective replacement for iliac crest autograft in human pos-terolateral lumbar fusion. The OP-1 group had a higher radiographic fusion rate than the autograft group. This correlated well with the greater clinical success experienced by the OP-1 group, as measured by improvement in the Oswestry score. None of the previously reported device related complications related to the use of BMPs in animal studies, such as exuberant bone growth with subsequent neural impingement, ectopic ossification, or spinal stenosis, was seen in the treatment group. CONCLUSION: OP-1 appears to be a safe and effective replacement for iliac crest autograft in human posterolateral lumbar fusion. The dose, 3.5 mg per side, and the carrier, a biodegradable putty, appear to provide a safe and effective means of delivering the bone morphogenetic protein OP-1 to the human lumbar spine

Purpose. Posterior lumbar fusion using minimally invasive surgical (MIS) techniques are reported to minimise postoperative pain, soft tissue damage and length of hospital stay when compared to the traditional open procedure. Methods. This is a review of patients who underwent MIS for posterolateral lumbar fusion in a single practice over a 2-year period. Results. Twenty-eight patients underwent this procedure. The median age was 57 (range 34-80). Male:female ratio was 1:1. The most common symptom was radicular pain (n=26). Two patients had back pain without radicular symptoms. Primary degenerative spondylolisthesis was seen in 22 patients and post-laminectomy spondylolisthesis in 3 patients. Transforaminal interbody fusion (TLIF) with pedicle screw fixation was the commonest procedure (20) while the rest had pedicle screw fixation and inter-transverse fusion. Along with fusion, nerve root decompression alone was performed in 19, while 5 had decompression of the central spinal canal. Intra-operative navigation was used to assist screw placement in 5 patients. The typical hospital stay was 3 days. All but two patients were mobilised the same or the following day. Twenty-one patients with radiculopathy (80%) reported improvement in VAS at 6-months. One patient suffered irreversible nerve root injury (L5). Significant pedicle breach without nerve injury by a screw was seen in one patient. Conclusion. Minimally invasive TLIF and pedicle screw fixation lumbar degenerative condition is a safe procedure with complications comparable to traditional open techniques. Minimal muscle dissection and soft tissue damage allows for earlier ambulation and reduced hospital stay. The procedure however required longer operative time and increased exposure to intra-operative x-rays

Instrumented fusion for lumbar degenerative spondylolisthesis (LDS) has been challenged recently with high impact trials demonstrating similar changes in health-related quality of life (HRQOL) and less morbidity/cost with laminectomy alone. Randomized trials often fail, however, to evaluate a heterogeneous population of patients. A standardized clinical assessment and management plan (SCAMP) was created as a decision aid for surgeons based on the radiographic stability and clinical presentation of patients. The purpose of this study was to compare outcomes of those patients who followed the decision aid with respect to fusion/no fusion to those who did not. Patients were prospectively enrolled from eleven different Canadian institutions and followed from 2015–2019. A degenerative spondylolisthesis instability classification system (DSIC) was created using best available evidence stratifying patients into three different subtypes (1. stable degenerative spondylolisthesis, 2. potentially unstable spondylolisthesis and 3. unstable spondylolisthesis). The decision aid recommends laminectomy alone for group 1 patients, posterolateral fusion with pedicle screws in type 2 patients and pedicle screw and interbody fusion for type 3 patients. One year changes in HRQOL, length of hospital stay (LOS), medication use and surgical time were compared between each group and in context of whether the treatment fell within the decision aid recommendation. Statistics were performed with STATA software. There were 394 patients initially enrolled and 334 (84.8%) with full one year data available for comparison. There were 95 type 1 (stable), 224 type 2 (potentially unstable) and 75 type 3 (unstable) patients initially classified. Baseline Ostwestry disability index (ODI), EQ-5D, and SF-12 MCS scores were significantly worse for type 3 patients versus type 1 patients. One hundred and eight patients were treated within the recommendations of the DSIC system (108/334, 32.3%). Surgeons performed interbody fusions in 141 patients (42%) rather than follow DSIC recommending a less invasive approach. There were no significant differences EQ-5D, SF-12 PCS/MCS, PHQ-9 or ODI at one year between patient groups. There was a trend towards shorter operating times for those patients following the DSIC system (195 minutes non-followers versus 180 followers, p=0.078) and reduced hospital stay (4.46 days non-followers versus 3.98 followers, p=0.065). There were no significant clinical differences in outcome at 1 year whether patients underwent decompression alone, decompression/posterolateral fusion or interbody fusion regardless of the stability classification. Surgeons were more likely to perform potentially unnecessary interbody fusions even in those patients with stable or potentially unstable spondylolisthesis. Although not statistically significant, there is some suggestion that following the DSIC system based on best evidence recommendations leads to more judicious/responsible use of hospital resources. Further study is required to determine why surgeons are more likely to choose more invasive, higher rigidity constructs in patients with LDS