Adolescent idiopathic scoliosis (AIS) is a poorly understood progressive curvature of the spine. The 3-dimmensionnal spinal deformation brings abnormal biomechanical stresses on the load-bearing organs. We have recently reported for the first time the presence of facet joint cartilage degeneration comparable to age-related osteoarthritis in scoliotic adolescents. To better understand the degenerative mechanisms and explore new therapeutic possibilities, we focused on Toll-like receptors (TLRs) which are germline-encoded pattern recognition receptors that recognize pathogens and endogenous proteins such as fragmented extracellular matrix components (alarmins) present in intervertebral discs (IVD) and articular cartilage. Once activated, they regulate the production pro-inflammatory cytokines, proteases and neurotrophins which can lead to matrix catabolism, inflammation and potentially pain. These mechanisms have however not been studied in the context of AIS or facet joints. Facet joints of AIS patients undergoing corrective surgery and of cadaveric donors (non-scoliotic) were collected from consenting patients or organ donors with ethical approval. Cartilage biopsies and chondrocytes were isolated using 3mm biopsy punches and collagenase type 2 digestion respectively. qPCR was used to assess gene expression of the degenerative factors (MMP3, MMP13, IL-1ß, IL-6, IL-8) The biopsies were cut into two equal halves, one was treated for 4 days with a TLR2 agonist (Pam2CSK4, Invivogen) in serum-free chondrocyte media while the other one was cultured in media alone. MMP3, MMP13, IL-6 and IL-8 ELISAs and DMMB assays were performed on the biopsy cultured media. The ex vivo cartilage was then fixed, cryosectionned and also stained with SafraninO-Fast Green dyes. Baseline gene expression levels of TLR1,−2,−4,−6 were all upregulated in scoliotic chondodryctes compared to non-scoliotic. Pearson correlation analysis revealed that all TLR1,−2,−4,−6 gene expression correlated strongly and significantly with degenerative markers (MMP3, MMP13, IL-6, IL-8) in scoliotic chondrocytes but not in non-scoliotic. (Figure 1) When monolayer facet joint chondrocytes were activated with Pam2CSk4, there was a significant upregulation in previously described degenerative markers, TLR2 and NGF, a potent neurotrophin. These findings were strengthened by protein secretion analysis of select markers such as MMP-3, −13, IL-6 and IL-8 which were all upregulated after TLR2 activation. The scoliotic biopsies which were treated with Pam2CSK4 had a significant loss of proteoglycan content as shown by histology, was reflected in the proteoglycan content found in the media by DMMB. TLR gene expression levels were upregulated and correlated with proteases and pro-inflammatory cytokines in degenerating scoliotic cartilage, suggesting they promote cartilage degradation, especially considering the lack of correlations in non-scoliotic healthy cartilage. Furthermore, when TLRs are activated by Pam2CSK4 it triggers the release of the same proteases and pro-inflammatory cytokines in our ex vivo experiment. All this exacerbates the loss of proteoglycan in the cartilage ex vivo model after four days of insult with a TLR2 specific agonist. These results suggest that TLRs are an important pathway partaking in the cartilage degeneration of scoliotic facet joints and potentially all cartilage beyond our scope. Future studies aim at blocking TLRs to alleviate proteolysis and inflammation. For any figures or tables, please contact the authors directly

Introduction Local steroid injection is commonly performed as a treatment for facet joint arthritis in the lumbosacral spine. The injection is performed under image guidance for which some surgeons utilise antero-posterior (A-P) imaging only while others prefer oblique imaging. The entry point and the direction of the needle entering into the facet joint are different in these techniques. Further the difficulties encountered in both the techniques are different. Purpose To find out the difference in the functional outcome in patients who received the facet joint steroid injection by A-P imaging and those who had the injection by oblique imaging. Material and Methods A prospective randomised controlled trial was performed by randomly allocating the 20 patients who was diagnosed to have facet joint arthritis clinically and by magnetic reasonance image scans, and who were then placed in the list for facet joint injections. Ten patients in Group I received the facet joint injections with A-P imaging while 10 patients in Group II received the facet joint injections with oblique imaging using image intensifier. All the patients received 40mg of methylprednisolone acetate with 1mL of 1% lignocaine and 1mL of 0.5% bupivacaine to each joint. The duration of the entire procedure was noted. Short Form-36 (SF-36) questionnaire was used before the procedure and at six weeks after the procedure to assess the functional outcome. Results All the patients were followed up for a period of six weeks. The mean age was 51.3 yrs in Group I and 48.3 yrs in Group II. The male to female ratio was 3:7 in Group I and 2:5 in Group II. One patient in Group I had the facet injections at only one level (L4/5 or L5/S1) while it was in two patients in Group II. Further one patient in Group I and one in Group two had unilateral facet joint injections at two levels. All the other patients had bilateral facet joint injections at two levels (L4/5 and L5/S1). One patient was excluded from the study as the A-P image obtained was very poor and that an oblique image had to be performed to visualise the facet joint because of obesity. The mean duration of the procedure was 18.33 min (10–25 min) in Group I and 22 min (10–35 min) in Group II (p=0.14, 95%CI −8.5 to +1.4). The patient function score improved from a mean of 20.0% to 32.5% after the injection in Group I, and from 30.0% to 41.0% in Group II. The pain score improved from a mean of 33.3% to 47.2% in Group I, and from 35.6% to 44.4% in Group II. The difference in physical function score (p=0.85, 95% C.I. −15.29 to +18.29), and pain score (p=0.71, 95% C.I. −24.21 to +34.22) between the two groups were not statistically significant. Conclusions There is no difference in the functional outcome of patients treated by facet joint injections using A-P or oblique imaging. However, with experience we found that it may be difficult to visualise the facet joint clearly by A-P imaging alone in obese individuals

Introduction: Pathological changes in the elderly spine include intervertebral disc degeneration, apophyseal joint arthritis and osteoporotic fracture of the vertebral body. Such changes are likely to be inter-related through alterations in the sharing of load between the apophyseal joints and the intervertebral disc unit. We describe an accurate, non-destructive method for calculating the load sharing based on measurements of the distribution of stress within the intervertebral disc. Materials and Methods: Twenty three motion segments, consisting of two vertebrae and the intervening disc and ligaments, were dissected from 17 human lumbar spines. A preliminary “creep” test was used to reduce disc height and water content by an amount equivalent to the diurnal variation seen in vivo. Then, a constant load was applied to each motion segment, using a computer-controlled hydraulic materials testing machine, for a period of 20s while a pressure-transducer, sensitive to spatial variations in compressive stress, was pulled through the disc along its mid-sagittal diameter. Profiles of vertically-acting compressive stress were obtained in each disc positioned in 2° of extension (appropriate for an erect standing posture). The total compressive force acting on the intervertebral disc was calculated by modelling the disc using approximately 20 elliptical rings of known cross-sectional area. The force acting on each ring was given by the product of area and the average compressive stress acting on it, which was obtained from the appropriate region of the stress profile. The total force acting through the disc was obtained by summing up the force contribution from each ring. The force acting on the apophyseal joints was calculated from the difference between applied (known) load and the calculated load acting on the disc. A correction factor was obtained separately for each disc to account for deviations in the cross-section from the elliptical, and variations in the sensitivity of the transducer in disc tissues of different ages. The correction factor was obtained by comparing the applied force with the force calculated from a stress profile measured before creep loading while the disc was in a neutral position, when the load passing through the apophyseal joints is negligible. Results: The proportion of load passing through the apophyseal joints increased significantly with age (r. 2. =0.48, p< 0.01), from 7% at age 27 yrs to 42% at 82yrs. Similarly, the proportion of load passing through the apophyseal joints increased with degree of disc degeneration (r. 2. =0.5, p< 0.05 Pearson, Chi-square) from 8% in “grade 1” discs to 40% in “grade 4” discs. Discussion: The compressive load passing through the apophyseal joints is higher than that predicted by previous, inaccurate, methods, or by experiments which failed to reduce the height and water content of the intervertebral disc. Increased load-bearing may be a contributing factor in apophyseal joint degeneration. Also, in lordotic postures, “stress shielding” by the apophyseal joints could contribute to bone loss in the vertebral body, leaving it vulnerable to osteoporotic fracture when the spine is loaded in flexion

Introduction Local steroid injection is commonly performed as a treatment for facet joint arthritis in the lumbosacral spine. The injection is performed under image guidance for which some surgeons utilise antero-posterior (A-P) imaging only while others prefer oblique imaging. Purpose The aim of this study is to find out the difference in the functional outcome in patients who received the facet joint steroid injection by A-P imaging and those who had the injection by oblique imaging. Material and Methods A prospective randomised controlled trial was performed by randomly allocating the 20 patients who were diagnosed to have facet joint arthritis clinically and by magnetic reasonance image scans, and who were then placed in the list for facet joint injections. Ten patients in Group I received the facet joint injections with A-P imaging while 10 patients in Group II received the facet joint injections with oblique imaging using image intensifier. All the patients received 40mg of methylprednisolone acetate with 1mL of 1% lignocaine and 1mL of 0.5% bupivacaine to each joint. The duration of the entire procedure was noted. Short Form-36 (SF-36) questionnaire was used before the procedure and at six weeks after the procedure to assess the functional outcome. Results All the patients were followed up for a period of six weeks. The mean age was 51.3 yrs in Group I and 48.3 yrs in Group II. The male to female ratio was 3:7 in Group I and 2:5 in Group II. One patient in Group I had the facet injections at only one level while it was in two patients in Group II (L4/5 or L5/S1). Further one patient in Group I and one in Group two had unilateral facet joint injections at two levels. All the other patients had bilateral facet joint injections at two levels (L4/5 and L5/S1). One patient was excluded from the study as the A-P image obtained was very poor and that an oblique image had to be performed to visualise the facet joint because of obesity. The mean duration of the procedure was 18.33 min (10–25 min) in Group I and 22 min (10–35 min) in Group II (p=0.14, 95%CI −8.5 to +1.4). The patient function score improved from a mean of 20.0% to 32.5% after the injection in Group I, and from 30.0% to 41.0% in Group II. The pain score improved from a mean of 33.3% to 47.2% in Group I, and from 35.6% to 44.4% in Group II. The difference in physical function score (p=0.85, 95% C.I. −15.29 to +18.29), and pain score(p=0.71, 95% C.I. −24.21 to +34.22) between the two groups were not statistically significant. Conclusions There is no difference in the functional outcome of patients treated by facet joint injections using A-P or oblique imaging. There is no significant difference in the duration of the procedure as well between the two techniques. However, with experience we found that it may be difficult to visualise the facet joint clearly by A-P imaging alone in obese individuals

Backpain is a common cause of patient referral to pain clinics. Around 120 000 patients with back pain are seen in UK Pain Clinics every year. Facet joint injections are a commonly used treatment modality. However there is considerable controversy regarding their efficacy. Most of the evidence supporting the use of injections is anecdotal, rather than being based on randomised studies. We carried out a prospective study to assess the efficacy of facet joint injections in relieving chronic low back pain. Our study group comprised 41 patients (57% females, 43% males). Patients completed the Oswestry Disability Index (ODI) and marked their pain levels on a Visual Analogue Scale (1 to 10). We found that though the pain score improved from 6.9 to 4.3, there was only a marginal improvement in the ODI from 52.5 to 50.8. Overall 85 % of patients experienced some improvement, while 15% felt their symptoms had worsened after the injections. One of the most significant findings of this study was the fact that the improvement in most patients lasted only for an average of three weeks. This is significantly less than most previous studies indicate. Interestingly, inspite of this limited improvement, almost all patients expressed the desire to be placed back on the list for repeat injections. Our study demonstrated a beneficial short term effect of facet joint injections. In our opinion, they are a reasonable adjunct to non operative treatment of chronic backpain

Aims: Comparison of the effectiveness of the injection of hyaluronic acid (Ostenil¨) and cortisone (Volon¨) into the facet joints in the treatment of facet joint syndrome. Methods: 60 patients suffering from low back pain due to degenerative arthritis of the facet joints were included in this randomized, controlled, double-blinded, clinical trial. 30 patients received intra-articular injections of hyaluronic acid (Ostenil¨) and 30 patients received intra-articular injections of 10mg triamcinolon-hexacetonid (Volon 10¨). The facet joints of the spinal segments L3/L4, L4/L5, and L5/S1 were injected bilaterally with computed tomography guidance in intervals of one week each. Clinical evaluation was carried out one week prior þrst injection, at the day of þrst injection, after one, two, and three weeks, and after three and six months. Clinical assessment was carried out using the visual analog scale for pain, the Roland Morris Questionnaire, and the Oswestry Disability Questionnaire. Quality of life was assessed using the SF-36 health questionnaire. Radiological assessment was done according to Kellgren. Results: Pain reduction was achieved faster in the Volon 10¨group. After three months the Ostenil¨group reached better pain reduction and this effect lasted for a longer period. The Roland Morris score, the Oswestry Disability Questionaire, as well as the Low Back Pain Outcome Score showed signiþcantly better results in the Ostenil¨group after 3 and 6 months follow-up. Conclusion: Even though no signiþcant difference was found in the short-term follow-up, the results in the Ostenil¨group were comparable to the Volon 10¨group, and were signiþcantly better in the long-term follow up. Thus the intra-articular injection of hyal-uronic acid (Ostenil¨) is an effective alternative in the treatment of low back pain caused by facet joint syndrome, avoiding the known side effects of cortisone

Purpose and Background. This pilot study aimed to determine the accuracy of lumbar spine combined movement (CM) testing for diagnosing facet joint mediated pain, by comparing CM to medial branch blocks (MBB) - the gold standard in the diagnosis of facet joint pain. A regular compression pattern of CM combines active extension and lateral flexion, which is believed to compress the facet joints greater than physiological uni-planar movements. Method and Results. 96 patients attending a pain clinic day case unit for diagnostic MBB were recruited. Patients' pain responses to CMs were measured prior to and thirty minutes following MBB. The effect of weight bearing and recumbence, RMDQ, EQ-5D and MYMOP were also measured. The regular compression CM test had 80% sensitivity (95%CI: 71% to 89%) and 50% specificity (95%CI: 28% to 71%). The regular compression CM group had the largest pre-post VAS difference (median 4 points). The patients whose pain was not relieved in recumbence (n=15) showed a significant VAS difference of 6 points p=0.001). There was a significant positive correlation between the pre and post pain scores, p<0.001. There was no association between MBB response and RMDQ, EQ-5D, MYMOP scores, duration of symptoms or standing as a provoking activity. Conclusion. Regular compression CM testing can be used as a diagnostic tool to identify patients with facet joint mediated pain, particularly when associated with high pain scores. Low back pain (LBP) provoked by standing and relieved with recumbence are common features in the LBP population but are not indicators of facet joint pathology, contrary to many clinicians' beliefs

Lumbar facet joint pain cannot be reliably diagnosed clinically, the International Spinal Injection Society recommends two diagnostic local anaesthetic blocks before radiofrequency (RF) denervation [. 1. ]. Scoring systems may improve diagnostic accuracy. The two most popular scores disagree on the interpretation of pain induced by extension/rotation:. ‘Cochin Criteria’ [. 2. ]: pain on extension/rotation _ not facet joint problem. Helbig & Lee [. 3. ]: pain on extension/rotation _ facet joint problem. Methods: Retrospective study of all patients who had RF denervations of the lumbar facet joints in 2004. Patients were selected clinically and did not undergo diagnostic blocks. Cochin criteria, Helbig & Lee scores, work status, and outcome were taken from the case notes. Likelihood ratios were calculated for the scores, their individual components, and work status. Results: 145 patients underwent RF facet joint denervation, for 127 all data was available. In 68 patients the procedure was successful (53.5%). Conclusion: Neither the Cochin Criteria nor the Helbig & Lee score can predict the response to radiofrequency denervation of the lumbar facet joints. Pain on extension/rotation weakly indicates a poor response to facet joint denervation. X-rays do not help with the diagnosis. Social factors may be more important than clinical signs

Background Context. SPECT-CT is a hybrid imaging modality, which has become very well established in the diagnosis of inflammatory, vascular and malignant processes affecting the spine. However, little evidence exists on its application with degenerative pathologies. Purpose & Study Design. Systematic review on the use of SPECT-CT in the diagnosis of degenerative facet joint arthropathy. Patient Sample. 824 patients across 10 studies conducted over the last 6 years (2012 – 2018), with a mean age of 51.8 years old. All studies excluded patients with malignancy, infection or inflammatory aetiologies or those related to acute trauma. Only degenerative pathologies of the lumbar spine in an adult population were included. Methods. A systematic review of the literature available on the topic was conducted using the PubMed, Cochrane, Medline and Embase online databases of journal articles. Results. Five studies focused on SPECT-CT alone / versus CT. Two focused on SPECT-CT vs MRI, and three focussed on SPECT-CT guided facet joint injections. Of these 10 studies, seven concluded with results supporting SPECT CT's use, two reported discordance between SPECT-CT findings with those diagnosed from clinical examination / MRI scans, and one study's conclusions were equivocal. Conclusion. SPECT-CT shows promise as an imaging adjunct in assisting with the diagnosis and subsequent treatment of degenerative facet joint arthropathies. In patients whose MRI scans reveal multiple potential pain generators, SPECT-CT could help differentiate between clinically significant sources of pain and may even serve a purpose in guiding facet joint injections in patients with inconclusive MRI / CT scans. No conflicts of interest. No funding obtained

Aims: To assess the effectiveness of intra-articular facet joint injections in controlling disability in patients with low back pain. Methods: 100 consecutive patients admitted in our day case unit for facet joint injections were included in the study. Fluoroscopically controlled intra-articular facet joint block with injection of a local anaesthetic and corticosteroid suspension was performed after clinical and radiological assessment. Disability due to back pain was assessed by determining a revised Oswestry Low Back Pain Disability Index (Oswestry Score). The patients completed a questionnaire immediately prior to treatment, two weeks following injection and three months following injection. Results: Facet joint injections were performed for intervertebral disc prolapse (66%), spondylolysthesis (13%), spinal stenosis (10%), spondylosis (7%), and sacro-iliac joint pain (4%). The mean Oswestry Score prior to injection was 40.6% (95% conþdence interval 4.4), at two weeks following injection was 26.6% (95% conþdence interval 4.9) and at three months following injection was 21.5% (95% conþdence interval 4.8). 78% of the patients found the facet joint injections useful at 2 weeks following treatment and this þgure was maintained (79%) at 3 months after injection. No complications were reported following treatment. Conclusions: We have found intra-articular facet joint block for the treatment of low back pain a valid therapeutic option, acceptable by the patients and with negligible risks

Introduction. Total disc replacement (TDR) provides an alternative to fusion that is designed to preserve motion at the treated level and restore disc height. The effects of TDR on spine biomechanics at the treated and adjacent levels are not fully understood. Thus, the present study investigated facet changes in contact pressure, peak contact pressure, force, peak force, and contact area at the facet joints after TDR. Methods. Seven fresh-frozen human cadaveric lumbar spines were potted at T12 and L5 and installed in a 6-DOF displacement-controlled testing system. Displacements of 15° flexion/extension, 10° right/left bending, and 10° right/left axial rotation were applied. Contact pressure, peak contact pressure, force, peak force and contact area for each facet joint were recorded at L2-L3 and L3-L4 before and after TDR at L3-L4 (ProDisc-L, Synthes Spine). The data were analysed with ANOVAs/t-tests. Results. Axial rotation had the most impact on contact pressure, peak contact pressure, force, peak force, and contact area in intact spines. During lateral bending and axial rotation, TDR resulted in a significant increase in facet forces at the level of treatment and a decrease in contact pressure, peak contact pressure, and peak force at the level superior to the TDR. With flexion/extension, there was a decrease in peak contact pressure and peak contact force at the superior level. Conclusion. Our study demonstrates that rotation is the most demanding motion for the spine. We also found an increase in facet forces at the treated level after TDR. To our knowledge, we are the first to show a decrease in several biomechanical parameters after TDR at the adjacent superior level in a cadaveric model. In general, our findings suggest there is an increase in loading of the facet joints at the level of disc implantation and an overall unloading effect at the level above

Background Context: One of the main postulated basic principles of total disc replacement (TDR) is the preservation of flexion/extension ability. In neutral position the ideal disc prosthesis should not stay in maximal possible extension which would imply an impingement of the prosthesis. An impingement would cause shear strains on the prosthesis endplates which probably accelerate loosening. Moreover an additional extension ability from the neutral position would indicate no impingement in the facet joints in neutral position and a physiological movement capability. Purpose: The purpose of study was to evaluate a possible impingement of the prosthesis or facet joints after TDR in neutral position. Study design: Prospective evaluation of radiological outcome measures after total disc replacement. Patient sample: The patients (19 female, 10 male) ranged from 29 to 56 years of age (mean: 42.46.5 years). The mean follow up interval averaged 13.2 months (range: 6 – 35 months). The diagnosis of degenerative disc disease was confirmed by MRI (black disc) and discography (positive „Memory pain“). Pain relief after facet joint infiltration was an exlucsion criteria. All patients had a single-level disc replacement (Prodisc II, Spine Solutions) with the same angulation (6). Outcome measures: Evaluation of a possible impingement of the prosthesis and impingement of facet joints in neutral position. Methods: A computer based analysis of pre- and postoperative lateral X-rays in neutral position and dynamic x-rays. The angulation of prosthesis in neutral position and the extension ability in dynamic x-rays were measured. Results: 15 patients showed no extension ability on dynamic x-rays and 10 of these 15 patients had an impingement with maximum extension of the prosthesis on x-rays in neutral position. In the remaining 14 patients the extension ability averaged pre-/postoperatively 2.3/1.3 (p=0.115). In 4 of the 14 patients the pros-thesis showed an impingement in maximum extension and in 10 patients the prosthesis was not in maximum possible extension. Conclusion: Due to the constrained design of the Pro-Disc an impingement is possible and was recognized in nearly 30% of the cases. The imbalance of flexion vs extension bending moments with increase in extension bending moments due to resection of the anterior longitudinal ligament and anterior anulus seems to be a possible explanation. It still remains unclear if an impingement will result in facet joint protection or will trigger a loosening of the implant. A prosthesis design which preserves the anterior longitudinal ligament would be probably a possible solution

Aims

To report the development of the technique for minimally invasive lumbar decompression using robotic-assisted navigation.

Aims. A systematic review of the available literature comparing the outcomes of radiofrequency denervation to sham procedure in treating chronic low back pain caused by lumber zygapophysial joint pathology. Methods. Medline and EMBASE databases were searched for English language articles from 2005 to July 2010. Articles were considered for review if they satisfied the inclusion criteria: Randomised Controlled Trials(RCT) comparing radiofrequency neurotomy(RFN) to a ‘placebo’ procedure in patients with chronic low back pain caused by facet joint osteoarthritis. Adult patients of both sexes above 17 years of age who complained of continuous low back pain for more than 6 months with focal tenderness over the facet joints. Outcome measures of interest are pain improvement, physical activity, analgesic use, quality of life variables, range of motion of the lumbar spine and hip movement. Critical appraisal of the selected studies was carried out using the CASP appraisal tool for RCT. Results. Two articles were identified. Both demonstrated a statistically significant improvement in the pain (p<0.05) using a visual analogue scale in the RFN group compared to the sham procedure. Only one trial demonstrated a corresponding reduction in analgesic use. There was no consensus of improvement of quality of life factors in either study as compared to placebo. Conclusion. Radiofrequency denervation is better than sham procedure in treating pain caused by facet joint osteoarthritis with minimal adverse effects in the short term. A higher powered trial using a larger cohort and longer follow up is required to resolve some of the equivocal results. Conflicts of Interest. None. Source of Funding. None

Lumbar steroid injection can be endorsed as a treatment component for lumbrosacral radicular pain syndrome resulting from disc herniation. The facet joint steroid injection seems to be beneficial for patients with chronic backache due to the facet joint arthritis and in the lumbar Spondylosis. We did a retrospective review of 31 patients whom we treated between 2004 and 2005 with follow up of 6 months to 24 months. There were 19 females and 12 males, aged between 29–81 years. Five patients had previous surgery for simple discectomy to posterior spinal fusion. Four patients had multiple disc prolapse at 3–4 levels, 2 patients had a severe lumbar spondylosis and spinal stenosis. The remaining 20 patients had a single level disc prolapse. All these patients were given caudal and facet joint blocks. The pre and post steroid injection Oswestry score was done. After steroid injection the Oswestry score improved by 30%. Majority of the patients had pain relief for 2–18 months. The pain relief was much better in the non operative group with single level disc pro-lapse and those patients with lumbar spondylosis. In patients with chronic back pain there is an inflammatory basis for pain generation. Lumbar steroid injection seems to be beneficial in patients with disc prolapse and lumbar spondylosis. In the literature various randomized trials have been done and their results are controversial. Our study showed definitive improvement in terms of pain and function of our patient

Objective: To document the incidence of adjacent superior segment facet joint violation following transpedicular instrumentation in the lumbar spine as it has been postulated that this can lead to long term deterioration There has been no study so far determining this incidence. Design: Patients undergoing lumbar fusion were prospectively evaluated with a CT scan and plain radiographs six months following surgery. These were blindly and independantly evaluated by a consultant radiologist and a research fellow. Subjects: 106 patients (212 top level facet screws) between 1996 and 1999 were evaluated. All patients had their screws and instrumentation inserted through a Wiltse muscle splitting approach and a lateral entry point in the pedicle so as to reduce the risk of facetal impingement. . 1. Outcome Measures: Kappa co-efficient and chi-squared analysis. Results: The Kappa co-efficient for the CT scan and plain radiographs were 0.88 and 0.39 respectively. On the CT scan both observers noted facet joint impingement in just over 20% of the screws and just over 30% of the patients. The impingement was independent of the level and diagnosis (p> 0.05) and it occurred with uniform incidence in each of the year. Conclusion: This study raises the theoretical possibility of long term deterioration in the clinical results following the use of transpedicular instrumentaion

Introduction: Analgesia from controlled injections of local anaesthetic into the lumbar zygapohysial joint (z-joint) has been accepted as the standard for diagnosis of z-joint pain. Little is known about the placebo-response rate. Aim of this pilot study is to validate the fluoroscopically controlled z-joint-injection (ZJI) as an instrument for diagnosis of degenerative symptomatic z-joint disease. Material and Methods: Due to degenerative lumbar spine syndrome 50 z-joints (L5/5: 27; L5/S1 23) were injected three times in a single blinded trial bilaterally. According to a randomisation protocol, using the oblique needle technique the ZJI were done with an local anaesthetic (LA: 1.5 ml 0.5% Scandicain), a saline placebo (sodium: 1.5ml 0.9% NaCl) and with no agent (sicca punction). The pain level before and after the injections (30 min, 1 and 2–3 hours) was documented by the patient on a 10pts.-VAS. Improvement in the pain level after an FJI is defined as responder. A responder reacts false positive if the degree of effectiveness of the placebo-FJI is the same or better than the response to LA. A patient reacts false negative if the pain diminution after LA application is lower than after placebo. Results: Preliminary results regarding the reactions 30 min after injection are presented. 26% were non-responder and 52.9% LA-responder. The sicca response rate was 38%, for sodium it was 46%. Reaction after sicca-FJI was false positive in 24%, after sodium-FJI in 32% of cases. 38% reacted false negative to LA-injection. The order of the agent application didn’t have significant influence on the responder rates and also not on the extent of contradictory effects. Conclusions: Despite numerous examinations none could sufficiently evaluate accurate reliable predictors for positive ZJI-responders till now. This is confirmed by our high LA-non-responder-rate of 48.1%. However, only a placebo injection can absolutely exclude a true placebo response. Placebo responses seem to be common. High specificity (minimization of the false positive results) and sensitivity (minimization of the false negative results) are characters for a good diagnostic test. In literature, the specificity of the intraarticular facet block as a diagnostic test for facet joint disease is currently unknown. Capsular rupture with epidural and periarticular diffusion is probably responsible for many false positive findings. Regarding our results, the validity of only one ZJI is not acceptable and shouldn’t be consulted as a diagnostic method for the identification of a facet joint syndrome, therefore. Pain relief after ZJI is a poor predictor of clinical outcome of posterolateral lumbosacral fusions when based on single blocks. Corresponding further examinations are necessary also regarding the ZJI-reliability

INTRODUCTION:. As a consequence from cervical arthroplasty, spine structural stiffness, loading and kinematics are changed, resulting in issues like adjacent segment degeneration and altered range of motion. However, complex anatomical structures and lack of adequate precision to study the facet joint (FJ) segmental motion in 3D have prevented proper quantitative analyses. In the current study, we investigate the innovative use of a local coordinate system on the surface of the superior articular process of the caudal vertebral body in order to analyze FJ segmental motion using CT-based 3D vertebral models in flexion/extension. METHODS:. CT images were obtained from six patients (2F/4M, mean age: 53 y.o.) with cervical degenerative disc disease in neutral, flexion and extension positions. CT data was used to create subject-specific surface mesh models of each vertebral body. From these, mean normal vectors were calculated for all FJ surfaces and posterior walls from C3/4 down to C6/7 (Fig. 1). The global coordinate system (x, y, z) corresponds to the CT scanner. Within this system, a new local coordinate system (u, v, w) was set on the centroid of each FJ surface (Fig. 1), where the u-, v-, and w- axes correspond to the normal-to-the-FJ, right-left and cranio-caudal directions, respectively. In flexion/extension, translations in mm were calculated as differences in the FJ centroid position and rotations were calculated in degrees as angular differences of the vector of the opposing surface in flexion/extension. Results are presented as mean ± SD. Differences within vertebral levels and left/right FJs were sought using 1- or 2-way ANOVA, respectively. RESULTS:. The flexion/extension segmental motion was described in its six degrees-of-freedom. Among the three translations, the largest movement was observed in the cranio-caudal direction (u = −0.22 ± 0.47 mm, v = 0.11 ± 0.89 mm, w = −2.06 ± 1.60 mm); while the three rotations about the (u, v, w) axes showed a dominant rotation about the v-axis (u = −0.41 ± 4.42°, v = −5.12 ± 5.61°, w = −0.01 ± 2.71°). Comparing translational and rotational motions by cervical level, movements at C6/7 were shown to be smaller than those at the other levels (p < 0.05) (Figs. 2, 3). There were no significant differences in the movement of the FJ between left and right sides (p > 0.05). DISCUSSION:. A key finding of this study was that along with the expected translation in the w-axis, there was rotation about the v-axis consistent with the overall neck flexion-to-extension motion. If the rotation about the v-axes were negligible, the FJ motion could be considered as a pure translation (sliding), but the data suggests otherwise. This finding supports the hypothesis of a rolling-sliding type of facet segmental motion that might be influenced by the facet surface curvature. Future studies will focus on analyses of the changes in FJ gap with motion and characterization of the facet surfaces' curvature and congruence. SIGNIFICANCE: An innovative look into flexion/extension motion from the FJ point of view describes FJ segmental motion as a sliding-rolling motion instead of the traditional concept of sliding-only mechanism

Percutaneous radiofrequency facet joint denervation (RFJD) has been used increasingly since being described by Shealy1 for the non-surgical treatment of chronic low back pain. Extensive literature exists on this technique with a number of randomised control studies suggesting efficacy against Placebo2,3. However, the efficacy and reliability of repeat RFJD for chronic back pain is unknown. A prospective study was carried out on a consecutive series of 57 patients undergoing repeat lumbar RFJD between 2004 & 2006. 57 consecutive patients treated by the senior author (OLO) between April 2004–June 2006 were included in a prospective analysis using a visual analogue score (VAS) and the low back outcome score (LBOS). All 57 participants completed a telephone questionnaire at follow up. There were no complications. At a median average follow up of 14 months overall, clinical outcomes demonstrated moderate improvement in the majority of patients with poor rating at LBOS decreasing from 54.3% pre- to 40.3% post-RFJD. The overall degree of satisfaction was 77.2%. The overall median duration of pain relief was 10 months. Our study suggests that repeat RFJD appears to have reliable and satisfactory results when repeated with most patients reporting a high degree of satisfaction and with the clinical outcome similar to the initial procedure

Introduction. Augmentation of spinal fusion using bone grafts is largely mediated by the osteoinductive potential of mesenchymal stem cells (MSC) that reside in cancellous bone. Iliac crest (IC) is a common autograft, but its use presents an increased risk for donor-site pain, morbidity and infection. Degenerative facet joints (FJ) harvested during facetectomy might servce as alternative local grafts. In this study, we conducted an intra-individual comparison of the osteogenic potential of MSC from both sources. Methods. IC and degenerative FJ were harvested from 8 consecutive patients undergoing transforaminal lumbar interbody fusion surgery for spinal stenosis. MSC were isolated by collagenase digestion, selected by plastic adherence and minimally expanded for downstream assays. Clonogenic and osteogenic potential was evaluated by colony formation assays in control and osteogenic culture medium. Osteogenic properties, including alkaline phosphatase (ALP) induction, matrix mineralization and type I collagen mRNA and protein expression were characterized using quantitative histochemical staining and reverse transcription PCR. Spontaneous adipogenesis was analysed by adipocyte enumeration and gene expression analysis of adipogenic markers. Results. Average colony-forming efficiency in osteogenic medium was equal between IC (38±12%) and FJ (36±11%). Osteogenic potential at the clonal level was 55±26 and 68±17% for IC and FJ MSC, respectively. Clonogenic and osteogenic potential were significantly negatively associated with donor age. Osteogenic differentiation led to significant induction of ALP activity in IC (6-fold) and FJ (8-fold) MSC. Matrix mineralization quantified by Alizarin red staining was increased by osteogenic differentiation, yet similar between both MSC sources. Protein expression of type I collagen was enhanced during osteogenesis and significantly greater in IC MSC. Correspondingly, COL1A2 mRNA expression was higher in osteogenically differentiated MSC from IC. Adipocyte numbers showed significant differences between IC (63±60) and FJ (18±15) MSC under osteogenic conditions. Negative (GREM1) and positive (FABP4) adipogenic markers were not differentially expressed between sources. Conclusion. MSC from IC and degenerative FJ largely display similar clonogenic and osteogenic properties in vitro. Differences at the molecular level are not likely to impair the osteoinductive capacity of FJ MSC. Facetectomy samples are viable bone autografts for intervertebral spinal fusion