Introduction: Minimally-invasive techniques are being advocated increasingly for spine surgery, on the grounds that they are less traumatic and reduce postoperative recovery time. A minimally-invasive technique for posterior lumbar interbody fusion (MPLIF) has become available. In order to compare its efficiency and effectiveness with the open technique (OPLIF), a prospective audit was undertaken.

Methods: Forty-seven adult patients with radicular pain resulting from isthmic or degenerative spondylolisthesis, with a slip less than 50%, and no previous surgery, elected to undergo either MPLIF (n = 23) or OPLIF (n = 24). The MPLIF procedure was performed through two, 2.5cm paramedian incisions using a tubular retractor system and dilators (METRx-MD, Medtronic Sofamor Danek, Memphis). OPLIF was performed thorugh a 10 cm midline incision. In both procedures, the listhesis was reduced using polyaxial pedicle screws, and reduction tabs or bolts (Expedium, Depuy); the disc space was distracted using interbody spacers (R-90, Metronic Sofamor Danek) and packed with iliac crest graft. Intra-operative and postoperative variables were recorded. Clinical outcomes were assessed, before and 12 months after surgery, using a visual analog scale for pain and the SF36 for function.

Results: The two groups were comparable, demographically and with rspect to clinical features at inception, save that the MPLIF group had signficantly greater disc heights. Listhesis (median; interquartile range) was reduced from 25% (20–32) to 8% (1–13) after OPLIF, and from 20% (15–25) to 5% (0–10) after MPLIF. Disc height was increased from 12% (6–17) of vertebral body height to 24% (20–26) after OPLIF, from 17% (10–23) to 30% (26–36) after MPLIF. Fusion was achieved in all patients except one in the PLIF group. After OPLIF, median scores (interquartile ranges) for leg pain reduced from 8 (7–9) to 1 (0–4); scores for back pain reduced from 8 (6–8) to 2 (1–4); social functioning improved from 38 (13–57) to 82 (47–100), and in physical functioning improved from 20 (5–48) to 68 (44–86). After MPLIF, leg pain reduced from 8 (7–9) to 1 (0–3); back pain reduced from 8 (8–10) to 2 (1–4); social functioning improved from 38 (25–66) to 75 (50–91), and physical functioning improved from 20 (10–48) to 65 (34–82). All improvements within groups were significant (p = 0.000), but no statistically significant differences occurred between the groups for any outcome measure. Improvements in leg pain amounted to an 88% reduction for both groups, Back pain improved by 64% after OPLIF and by 78% after MPLIF. Duration of surgery and need for transfusion were not different between groups (5 patients required transfusion during OPLIF, and 1 during MPLIF (p = 0.09)); but the MPLIF patients had significantly shorter delays before commencing and achieving mobilization post-operatively, and had a shorter length of stay (4 days v 7 days).

Discussion: Clinical outcomes after MPLIF and OPLIF were not statistically different. Both procedures reduced back pain as well as leg pain, and restored function. Although there was no detectable correlation between pain and function before treatment, relief of pain was strongly correlated with restoration of function, after treatment. The advantage of MPLIF is that promotes faster recovery and shortens hospital stay. Its only disadvantage is the need to adapt to the technology involved and becoming familiar and confident with its use.

Introduction: Practice guidelines recommend functional restoration as a cardinal intervention for chronic low back pain. Published studies attest variously to either modest or good efficacy for functional restoration programs. However, although published data might set a benchmark of what outcomes can be achieved in research studies, they do not necessarily indicate what is actually achieved in conventional practice.

Methods: A prospective audit was undertaken of all patients referred for functional restoration in a rehabilitation service dedicated primarily to the treatment of low back pain. In accordance with published principles 1, the program provided education and physical rehabilitation in a cognitive-behavioural milieu. Before treatment, immediately after treatment, and three months and six months later, patients were assessed, by a research nurse not involved in the patients’ care, using a visual analogue scale for pain, the SF36 for function, a patient-specified functional outcome scale, and the treatment helpfulness questionnaire. As well, the need for other care was recorded.

Results: Forty-six patients enrolled in the study, but nine did not complete the rehabilitation program, and five withdrew their consent. Only two were lost to follow-up. Before treatment, those patients who withdrew and those who participated did not differ in presenting features. All had a moderate level of pain; they were moderately disabled in physical functioning, social functioning, and vitality; but were only slightly impaired in general health and mental health. All could nominate four activities of daily living that were impaired by their pain and which most dearly they would want restored. After treatment, median pain scores did not improve; nor was physical functioning, or social functioning, or vitality improved. Only one patient restored their desired activities of daily living. The majority of patients (25/30) restored no activity. These outcomes did not improve at the 3-month or 6 month-review. Patients previously unemployed remained unemployed. The proportion of patients previously employed (80%) fell immediately after treatment (70%) and remained stable thereafter. All patients required some form of continuing care from their general practitioner. Notwithstanding these outcomes, the majority of patients rated the program as helpful (57%) or extremely helpful (33%).

Discussion: The sample size in the present study was similar to that used in the original studies that promoted functional restoration. Statistically and clinically, the outcomes in this audit are incompatible and totally dissonant with published claims of 80% success rates for functional restoration programs. The 95% confidence intervals of a success rate of zero are 0 to 11%, which fails to reach the lower 95% confidence interval of 80%, which is 66%. These results warn that what is achieved in conventional practice may not reflect the benchmarks established in the literature. Evidence from research may not translate into standards of practice. Citing the literature is not a substitute or surrogate for auditing one’s own outcomes.

Introduction: Biacuplasty is an innovative intervention for the treatment of discogenic pain. It involves inserting electrodes bilaterally into the posterolateral corner of the anulus fibrosus. Radiofrequency current is passed between the electrodes, but each electrode is water-cooled. This prevents coagulation occurring around the surface of the electrode, which allows a three-dimensional lesion to develop between the electrodes. Theoretically this lesion would seal radial and circumferential fissures, and coagulate nerve endings throughout the posterior anulus.

Methods: As part of a multi-centre, limited release of biacuplasty, a prospective audit of outcomes was undertaken in 8 patients with chronic low back pain, in whom discography reproduced their pain and post-discography CT demonstrated a radial fissure. They were 6 men and 2 women, aged between 34 and 58 years, who had back pain for longer than 4 years. Four were still working but four were on workers compensation. At the time of writing, all patients had completed clinical assessments before treatment and at one, two, three, and six months after treatment, using a visual analogue scale for pain, and the Oswestry Disability Questionnaire (ODQ) and the SF36 for disability and function.

Results: Performed under local anaesthesia, the procedure was painless, and took less than one hour to complete. No complications occurred, and no patient suffered any side-effects. Group pain scores (median; interquartile range) at inception (69; 53–78) improved significantly at one month (35; 11–65) (p = 0.05); deteriorated by three months (41; 14–72) (p = 0.14); but were stable at 6 motns (40; 22–69). Scores for disability (54; 42–67) and physical functioning (33; 13–48) improved (to 50; 29–62 and 50; 20–59, respectively) but did not achieve statistical significance. In categorical terms, however, four patients obtained no benefit, one patient obtained partial, but worthwhile, reduction in pain, but three patients achieved greater than 50% relief of pain at three months, and four did so at 6 months. Reduction in pain was corroborated by a decrease in disability on the ODQ by 11 (5,2) points at three months, and 10 (−4, 15) points at 6 months; and increases in physical functioning on the SF36 by 15 (6,2) points at three months, and 5 (2,2) points at six months.

Discussion: These results in Australian patients echo those reported in one of the US arms of the study, in which 8 of 13 patients reduced their pain scores by at least 30 points. Attractive about this new procedure was its ease of execution and painlessness. Although the success rate is modest, this procedure could emerge as an entertainable option for the management of discogenic pain, if its effectiveness can be corroborated in a larger sample and for a longer time.

The pathophysiology of intervertebral disc degeneration has been extensively studied. Various factors have been suggested as influencing its aetiology, including mechanical factors, such as compressive loading, shear stress and vibration, as well as ageing, genetic, systemic and toxic factors, which can lead to degeneration of the disc through biochemical reactions. How are these factors linked? What is their individual importance? There is no clear evidence indicating whether ageing in the presence of repetitive injury or repetitive injury in the absence of ageing plays a greater role in the degenerative process. Mechanical factors can trigger biochemical reactions which, in turn, may promote the normal biological changes of ageing, which can also be accelerated by genetic factors. Degradation of the molecular structure of the disc during ageing renders it more susceptible to superimposed mechanical injuries.

This review supports the theory that degeneration of the disc has a complex multifactorial aetiology. Which factors initiate the events in the degenerative cascade is a question that remains unanswered, but most evidence points to an age-related process influenced primarily by mechanical and genetic factors.

Introduction Although manual therapists believe that they can diagnose symptomatic joints in the neck by manual examination, that conviction is based on only one study. That study claimed that manual examination of the neck had 100% sensitivity and 100% specificity for diagnosing painful zygapophysial joints. However, the study indicated that its results should be reproduced before they could be generalized. The present study was undertaken to answer the call for replication studies. The objective was to determine the sensitivity, specificity, and likelihood ratio of manual examination for the diagnosis of cervical zygapophysial joint pain. The study was conducted in a private practice located in a rural town. The practice specialised in musculoskeletal pain problems.

Methods Patients who exhibited the putatively diagnostic physical signs of cervical zygapophysial joint pain were referred to a radiologist who performed controlled, diagnostic blocks of the suspected joint, and other joints if indicated. The results of the blocks constituted the criterion standard, against which the clinical diagnosis was compared, by creating contingency tables. The validity of manual diagnosis was determined by calculating its sensitivity, specificity, and positive likelihood ratio.

Results The study sample was 173 patients with neck pain in whom cervical zygapophysial joint pain was suspected on clinical examination, and who were willing to undergo controlled diagnostic blocks of the suspected joint or joints. Manual examination had a high sensitivity for cervical zygapophysial joint pain, at the segmental levels commonly symptomatic, but its specificity was poor. Likelihood ratios barely greater than 1.0 indicated that manual examination lacked validity. Although the results obtained were less favourable than those of the previous study, paradoxically they were statistically not different.

Discussion The present study found manual examination of the cervical spine to lack validity for the diagnosis of cervical zygapophysial joint pain. It refutes the conclusion of the one previous study. The paradoxical lack of statistical difference between the two studies is accounted for by the small sample size of the previous study.

Introduction The aim of the study was to determine the prevalence of different causes of neck pain in a private practice clinic by a retrospective audit of records.

Methods The study included all consecutive patients attending a private spine pain clinic in the state of Washington, USA, seen between January 2003 and January 2005, in whom a diagnosis of neck pain was made. The records of all patients were examined to determine the prevalence of various diagnostic entities determined by history, examination, and invasive tests such as controlled diagnostic blocks and provocation discography. Using different denominators, the prevalence of various conditions was determined in all patients who presented with neck pain, in patients in whom investigations were undertaken, and in patients who completed investigations.

Results A large proportion of patients (35%) did not pursue investigations, which diluted the crude prevalence of various conditions. A further 17% deferred completing investigations. Amongst the 48% of patients who completed investigations, the prevalence of zygapophysial joint pain was 55%, discogenic pain was 16%, and lateral atlanto-axial joint pain was 9%. A diagnosis remained elusive in only 17% of those patients who completed investigations.

Discussion In a private practice setting, a patho-anatomic diagnosis for chronic neck pain can be established in over 80% of patients, provided that appropriate investigations are undertaken. The prevalence of cervical zygapophysial joint pain encountered in the present study corroborates the prevalence rates established in academic studies. The observed prevalence of discogenic pain is probably an underestimate because not all eligible patients underwent discography.

Introduction Compared to migraine and tension headache, headaches of cervical origin are better understood in terms of anatomy and physiology yet are least well accepted. What is controversial is not whether cervical headaches occur, but how often they occur and how they can be reliably distinguished from other entities. Using controlled diagnostic blocks Lord ( Lord SM et al. J Neuro Neurosurg Psychiatry 1994, Barnsley L et al. Pain 1993) implicated the C2/3 zygapophysial (Z) joint as the primary source of referred pain in 58% of patients in whom headache was the dominant symptom following whiplash injury. There are no other equivalent studies. The purpose of the study was to determine the prevalence of cervicogenic headaches arising from the Z-joints; to determine their segmental origin, and to construct an evidence-based diagnostic and therapeutic algorithm.

Method Of 241 patients referred to a tertiary pain unit, with a history of posttraumatic chronic neck pain, 133 had accompanying headache which at times was a dominant feature. All 133 consented to undergo comparative diagnostic blocks under double blind conditions and each was randomly assigned to receive either lignocaine or bupivacaine (2) An independent observer recorded pre-and post-injection pain scores for the first 24 hours and where indicated, the alternative agent was injected a week later. A block was deemed to be successful when the patient reported total abolition of the index pain (i.e. VAS=0) on two separate occasions at least a week apart . The lateral atlantoaxial (C1/2) joints were blocked by intra-articular injection. Medial branch blocks were performed for the remaining synovial joints. The atlanto-occipital (C0/C1) joints were not accessed. All blocks were executed under aseptic conditions and with fluoroscopic guidance.

Results Of 191 joints investigated, 122 (64%) were positive. The C2/3 joint contributed 36% whilst the C3/4 and C1/2 accounted for 13% and 6% respectively. The C6/7 was implicated in one instance and the remaining 8% was equally shared between the C4/5 and C5/6 levels. Segmentally, the respective positive rates at C2/3 and C1/2 were 72% and 56%. Investigating the C1/2 joint was a later development and hence it is likely that the 6% is an underestimate and a proportion may remain “hidden” in the 28% C2/3 negatives. The upper three joints accounted for 85% of all positive blocks (N=122) and this correlates with the known neuroanatomy. In patients where headache was the dominant symptom, all 68 positive blocks (100%) were obtained at the upper three joints.

Discussion Cervicogenic headache is not uncommon and unlike other primary headaches can be diagnosed with certainty. The definitive criterion is complete relief of pain after controlled diagnostic blocks. Valid treatment is available (Govind J et al. J Neurol Neurosurg Psychiatry 2003). Early diagnosis and prompt treatment have considerable economic, non-economic and psychological benefits; with concomitant reduction in iatrogenesis, morbidity and mortality.

Introduction: Contrary to the prevailing conviction that lumbar segments affected by lytic spondylolisthesis are unstable, multiple studies have failed to find evidence of increased or abnormal motion at these segments. Affected segments do not exhibit excessive anterior translation: the so-called slip. Previous studies, however, did not use techniques that might reveal abnormalities in the quality of motion, as opposed to its magnitude.

Methods: To determine if features of instability could be detected in the radiographs of patients with spondylolisthesis, a retrospective, cohort study was conducted of the kinematics of the lumbar spine of patients with spondylolisthesis compared with asymptomatic normal subjects. The flexion-extension radiographs of 15 patients with spondylolytic spondylolisthesis were analysed to determine the location of their instantaneous centres of rotation, and their magnitudes of translation and sagittal rotation. Normative data were obtained by applying the same techniques to the radiographs of 20 asymptomatic subjects.

Results: All but one of the 15 patients exhibited at least one segment with abnormal motion. Only one patient had excessive translation at the lytic segment. Four had minor abnormalities affecting either the lytic segment or ones above. Nine patients exhibited major abnormalities. Seven had paradoxical motion at the lytic segment, in which the centre of rotation was located above L5, instead of below, and in which L5 translated backwards, instead of forwards, during flexion. Two patients exhibited axial dropping of L4, instead of horizontal translation, during extension.

Discussion: Not all patients with spondylolisthesis show features of instability. However, a proportion of patients exhibit highly abnormal movements that are consistent with instability. The abnormalities involve movements within normal range but in abnormal directions. Visual inspection of radiographs will not reveal these abnormalities but they can be detected by plotting the instantaneous axes of rotation.

Introduction: Intradiscal electrothermal therapy (IDET) is a controversial, new treatment for low back pain, whose efficacy has not been tested in randomized trials. The present study was undertaken to compare the efficacy of IDET with that of a placebo treatment.

Methods: Patients were recruited by referral and by advertising in the media. Of 4,530 individuals who enquired, 1,360 were prepared to submit to randomization. Of these, 260 were found potentially eligible after clinical examination, and 64 became eligible after discography. All had discogenic low back pain lasting longer than 6 months, with no comorbidity. Thirty-seven were allocated to IDET, and 27 to sham therapy. Both groups were satisfactorily matched for demographic and clinical features. IDET was performed using a standard protocol, in which the posterior annulus of the painful disc was heated to 90°C. Sham therapy consisted of introducing a needle onto the disc and exposing the patient to the same visual and auditory environment as for a real procedure. Follow-up at 6 months was achieved in over 85% of patients. Pain and disability were assessed using a visual analog scale for pain, the SF-36, the Oswestry disability scale, and the Back Depression Inventory.

Results: Patients in both groups exhibited improvements, but improvements in pain, disability, and depression, were significantly greater in the group treated with IDET. Pain scores improved by 24 points in the IDET group compared with 11 in the sham group. Oswestry scores improved by 11 in the IDET group, but only by 4 in the sham group. More patients deteriorated when subjected to sham treatment, whereas eight patients (25%) achieved greater than 75% relief of pain following IDET. Only one patient did so after sham treatment. The number needed to treat, to achieve 75% relief of pain, was 5. No patient suffered any adverse effects.

Discussion: IDET fails to provide relief in some 50% of patients. Consequently, its efficacy is difficult to demonstrate statistically. Nevertheless, IDET provides satisfying relief in a substantial proportion of patients. Non-specific factors account for a large proportion of the apparent efficacy of IDET, but its efficacy cannot be attributed wholly to a placebo effect. The efficacy of IDET may be related critically to patient selection and the technique used. Improvements in either of these areas may improve the effect-size of IDET. Meanwhile, IDET is a low risk procedure that constitutes a legitimate option for patients with discogenic low back pain whose only alternative is fusion.

INTRODUCTION: Intradiscal electrothermal therapy (IDET) is a controversial, new treatment for low back pain, whose efficacy has not been tested in randomised trials. The present study was undertaken to compare the efficacy of IDET with that of a placebo treatment.

METHODS: Patients were recruited by referral and by advertising in the media. Of 4,530 individuals who enquired, 1,360 were prepared to submit to randomisation. Of these, 260 were found potentially eligible after clinical examination, and 64 became eligible after discography. All had discogenic low back pain lasting longer than six months, with no co-morbidity. Thirty-seven were allocated to IDET, and 27 to sham therapy. Both groups were satisfactorily matched for demographic and clinical features. IDET was performed using a standard protocol, in which the posterior annulus of the painful disc was heated to 90°C. Sham therapy consisted of introducing a needle on to the disc and exposing the patient to the same visual and auditory environment as for a real procedure. Follow-up at six months was achieved in over 85% of patients. Pain and disability were assessed using a visual analog scale for pain, the SF-36, the Oswestry disability scale, and the Back Depression Inventory.

RESULTS: Patients in both groups exhibited improvements, but improvements in pain, disability, and depression, were significantly greater in the group treated with IDET. Pain scores improved by 24 points in the IDET group compared with 11 in the sham group. Oswestry scores improved by 11 in the IDET group, but only by four in the sham group. More patients deteriorated when subjected to sham treatment, whereas eight patients (25%) achieved greater than 75% relief of pain following IDET. Only one patient did so after sham treatment. The number needed to treat, to achieve 75% relief of pain, was five. No patient suffered any adverse effects.

DISCUSSION: IDET fails to provide relief in some 50% of patients. Consequently, its efficacy is difficult to demonstrate statistically. Nevertheless, IDET provides satisfying relief in a substantial proportion of patients. Non-specific factors account for a large proportion of the apparent efficacy of IDET, but its efficacy cannot be attributed wholly to a placebo effect. The efficacy of IDET may be related critically to patient selection and the technique used. Improvements in either of these areas may improve the effect-size of IDET. Meanwhile, IDET is a low risk procedure that constitutes a legitimate option for patients with discogenic low back pain whose only alternative is fusion.

INTRODUCTION: Contrary to the prevailing conviction that lumbar segments affected by lytic spondylolisthesis are unstable, multiple studies have failed to find evidence of increased or abnormal motion at these segments. Affected segments do not exhibit excessive anterior translation: the so-called slip. Previous studies, however, did not use techniques that might reveal abnormalities in the quality of motion, as opposed to its magnitude.

METHODS: To determine if features of instability could be detected in the radiographs of patients with spondylolisthesis, a retrospective, cohort study was conducted of the kinematics of the lumbar spine of patients with spondylolisthesis compared with asymptomatic normal subjects. The flexion-extension radiographs of 15 patients with spondylolytic spondylolisthesis were analysed to determine the location of their instantaneous centres of rotation, and their magnitudes of translation and sagittal rotation. Normative data were obtained by applying the same techniques to the radiographs of 20 asymptomatic subjects.

RESULTS: All but one of the 15 patients exhibited at least one segment with abnormal motion. Only one patient had excessive translation at the lytic segment. Four had minor abnormalities affecting either the lytic segment or ones above. Nine patients exhibited major abnormalities. Seven had paradoxical motion at the lytic segment, in which the centre of rotation was located above L5, instead of below, and in which L5 translated backwards, instead of forwards, during flexion. Two patients exhibited axial dropping of L4, instead of horizontal translation, during extension.

DISCUSSION: Not all patients with spondylolisthesis show features of instability. However, a proportion of patients exhibit highly abnormal movements that are consistent with instability. The abnormalities involve movements within normal range but in abnormal directions. Visual inspection of radiographs will not reveal these abnormalities but they can be detected by plotting the instantaneous axes of rotation.

Introduction: On the basis of observational data, intradiscal electrothermal anuloplasty (IDETA) has been implemented as a treatment for back pain due to internal disc disruption. In order to assess the efficacy of IDETA, a prospective cohort study with comparison group was commenced in 1998. The present study provides the two-year results of that study.

Methods: Of 53 patients who satisfied the diagnostic criteria for internal disc disruption 36 were allocated to a treatment group and 17 to a comparison group, according to whether or not their insurer approved treatment with IDETA. Outcomes were assessed in terms of relief of pain, return to work, and use of opioids to treat persisting pain, at three months, twelve months, and two years after treatment.

Results: As a group, the comparison patients exhibited no significant improvement in their pain at any time. One was partially relieved, but no patient was completely relieved at either 12 or 24 months. The patients treated with IDETA exhibited significant improvements in their median pain scores, which were sustained at 12 and 24 months. At 24 months, 54% of these patients had achieved at least 50% relief of their pain, no longer used opioids, and were at work. Seven patients (20%) were totally free of pain and at work at 24 months.

Discussion: Despite the small sample size, the study had 90% power to detect the differences encountered at three months, 78% power at two years. The long-term results of IDETA are stable and enduring. It is not universally successful, but 54% of patients can reduce their pain by half, and one in five patients can expect to achieve complete relief of their pain. The results encountered in the present study are better than those reported in the literature, but may be attributed to more stringent selection of patients and closer attention to the accuracy of operative technique. Given the benchmark established by this study, consumers should beware of observational and controlled studies that achieve lesser results, lest these be used to impugn the procedure rather than the operator.