Introduction: The role of spinal fusion in patients suffering degenerative spine disease may be scrutinized more as costs of surgical treatment rise. Health-related quality of life (HRQL) measurement instruments enable outcome comparisons following treatment of different medical conditions. Rampersaud et al (1) recently presented the results of a comparative study of HRQL outcomes after surgery for lumbar spinal stenosis and hip and knee total joint arthroplasty. The latter are now accepted benchmarks for improvement in patient health.

Methods: A retrospective, observational cohort study was undertaken of 12-item Short Form Health Survey (SF-12) outcome data of 105 consecutive patients of two surgeons (1st and 2nd authors) who underwent single level Posterior Lumbar Interbody Fusion (PLIF) for lumbar spinal stenosis associated with degenerative spondylolisthesis. Minimum 12-month (F/U) data was available for 98 patients (93%). Comparison was made with published SF-12 results of hip and knee total joint arthroplasty (THR and TKR) and with age-related Australian population norms. Analyses were performed using XLSTAT version 7.5.3. Non-parametric statistics were used for assessment of skewed continuous variables. Overlappng 95%CIs were interpreted as indicating lack of significant difference in outcomes between patient and population groups.

Results: Median follow-up was 24months (range: 12–60months). Median age was 65 (Interquartile range: 59–75) years. Male:female ratio 2.8:1

Mean (95%CI) pre-op Physical Component Summary score (PCS) was 28.1 (26.6–29.5). This increased at last F/U to 39.3 (36.9–41.7, P< 0.0001). Mean Mental Component Summary score (MCS) was 47.8 (45.5–50.1) pre-op and 52.3 (50.2–54.5) at last F/U (P=< 0.0001).

While there was no difference in patient demographics, a significant difference existed in the pre-op SF-12 scores between the patients of the two surgeons (mean PCS: 24.9 (22.7–27.0) vs. 29.6 (27.8–31.5) and MCS: 44.0 (39.3–48.6) vs. 49.5 (46.8–52.1)). No significant difference was found in the improvements in mean SF-12 scores between these two patient groups (PCS: 12.3 (7.6–17.1) vs. 10.8 (8.3–13.3) and MCS: 6.3 (1.8–10.8) vs. 3.0 (0.3–5.6)) or in the SF-12 scores at 12-months (PCS: 37.2 (32.8–41.6) vs. 40.2 (37.2–43.2) and MCS: 52 (48.3–55.7) vs. 52.3 (50.1–54.4)). No significant difference was found between post-op PCS of the less disabled patient group or MCS scores of either group and published SF-12 age-matched population norms (65–74 years: mean PCS of 44.4 (42.7–46.1) and MCS of 53.8 (52.7–55.0)).

Three published series (869 patients) were located providing SF-12 data for TKR surgery. Weighted mean age was 69 years and pre-op PCS was 30 (range:27–34). 12-month improvement in PCS was 7.0 (range:7–8.5). For THR, one paper (147 patients from 3 hospitals) containing SF-12 data was found. Mean age was 68 years (range:36–89). Mean pre-op PCS and MCS of 30.5 and 41.4, increased to 45.6 and 49.7 at one year.

Discussion: The current study shows that spinal fusion can return patients’ HRQL to that of age-matched population norms and yield outcomes comparable to those of total hip and knee arthroplasty. Strict comparison with the arthroplasty literature was problematic however owing to variations in the methodology of their data presentation. Prospective collaboration with surgical colleagues in other disciplines is required.

Introduction Two commonly used labels for low back pain (LBP) are that of “mechanical” (1) or “inflammatory” (2). These labels have no universally accepted definitions. However, there are two distinct types of treatment for low back pain that seem to follow this definitional separation. That is, mechanical treatments (mobilisation, manipulation, traction and exercise) contrasted with anti-inflammatory treatments (medication and injections). The objective of this study was to obtain the opinion of five groups of experts about symptoms/ signs that may identify inflammatory and mechanical LBP.

Methods A convenience sample of 125 practitioners including spine surgeons, rheumatologists, musculoskeletal physicians, chiropractors and physiotherapists was asked to complete a questionnaire. Participants were asked to use a Likert (0–10) scale to indicate the strength of agreement or disagreement with respect to potential signs/symptoms identifying inflammatory or mechanical LBP. Ethics approval was obtained.

Results One hundred and five practitioners responded (81% response). No signs/symptoms were found to clearly distinguish between inflammatory and mechanical LBP. Nevertheless, seven signs/symptoms did show a higher score for either inflammatory or mechanical LBP, and a lower score for the other. Morning pain on waking, pain that wakes the person up, constant pain, and stiffness after resting (including sitting) were more likely to suggest inflammatory LBP, while intermittent pain during the day, pain when lifting and pain on repetitive bending were more likely to suggest mechanical LBP. There was however some disagreement between professions about the extent to which these signs/symptoms indicated mechanical or inflammatory LBP.

Discussion There was no clear agreement either within or between professions regarding the signs and symptoms that suggest mechanical or inflammatory low back pain. There was however weak agreement on seven signs/symptoms. Further research should be aimed at testing these for their ability to predict the outcome of mechanical and anti-inflammatory treatments of LBP.

Introduction Zygapophysial joint pain can be treated by RF neurotomy of the medial branch of the dorsal primary rami of the adjacent spinal nerves. The provision of radiofrequency (RF) neurotomy for spinal joint pain has been highlighted as an emerging trend in Australia, Europe and North America. However, there is controversy regarding the efficacy of this procedure. RF neurotomy for spinal pain has been investigated in several experimental and observational studies but these have reported conflicting results.

The purpose of this project was to provide a systematic review of the literature on RF neurotomy for the treatment of spinal pain of zygapophysial joint origin.

Method Electronic database searches, screening of reference lists, hand searching and consultation with experts in the field was undertaken to identify relevant studies. Publications were selected based on predetermined inclusion criteria and the methodological quality of each was rated. Qualitative analysis was performed using the Cochrane Collaboration Back Review Group (CCBRG) levels of evidence (RCTs only) and those used by the National Health and Medical Research Council (NHMRC) (RCTs, observational studies, systematic reviews and guidelines)

Results The search strategy identified 382 potential publications. Of these, 80 studies were selected for review, including 7 RCTs, 52 observational studies, 11 systematic reviews and 10 guidelines. There is conflicting (CCBRG) evidence regarding the efficacy of RF neurotomy for lumbar zygapophysial joint pain. The conclusions of systematic reviews and observational studies are conflicting regarding the efficacy of this procedure for the lumbar spine. In contrast, there is limited (CCBRG) evidence that RF neurotomy is efficacious for neck pain of zygapophysial joint origin in the short term. However, this was reported in one very small RCT which reported only one composite outcome.

Discussion This systematic review found that there is no consistent evidence from either multiple (large) RCTs or systematic reviews that RF neurotomy is efficacious in the treatment of spinal joint pain RCTs need to be conducted with larger sample sizes, (patient) relevant outcomes and adequate assessment of side-effects, which can be serious.

To investigate the efficacy of hyperbaric oxygen (HBO) in improving outcomes following open tibial fractures.

A prospective randomized controlled trial was conducted on patients presenting to an adult level 1 trauma centre with severe open tibial fractures (Gustillo 3B,3C). The primary outcome measure was soft tissue healing without secondary necrosis. Based on previously reported complication rates, 36 patients had to be randomized into each group in order to have ≥ 80% chance of detecting an improvement in necrosis free soft tissue healing rates from 70% to 95%. Secondary outcome measures included amputation, non-union, osteomyelitis and chronic pain rates, lower limb function and health related quality of life. The Alfred Hospital Human Research Ethics Committee approved conduct of the trial.

The trial was abandoned after 17 patients were randomised because the number of severe open tibial fractures presenting and complication rates were significantly lower than previously observed and because some surgeons declined to enrol patients in the belief that HBO was efficacious. Randomised patients were followed as per protocol but there were insufficient patients enrolled to observe any positive or negative differences in outcome. The logistics of treating major trauma patients with HBO proved readily manageable in the Alfred Hospital setting.

The efficacy of HBO in improving outcomes following open tibial fractures remains unknown. An international collaboration has been formed with the aim of commencing a multi-centre prospective randomized controlled trial of HBO in the near future.

The aim of this study was to determine predictors of persisting moderate/severe pain post orthopaedic injury.

Data were obtained from patients presenting to the two adult level 1 trauma centres in Victoria, Australia between August 2003 and August 2004. The maximum self reported pain levels at discharge and at 6 months post injury were determined using 11-point visual analogue scales (VAS). Moderate/severe pain was defined as a VAS score of 5 or greater. Associations between categorical variables were determined using chi-square tests and adjusted using multivariate logistic regression to determine possible predictors of persistent pain.

Data were obtained from 742 patients (age 15–100 years, 60.7% male). 37.1% had moderate/severe pain 6 months post injury. Moderate/severe pain at discharge was associated with an increased risk (OR 2.46 (95%CI 1.72–3.52), p< 0.0001) and isolated upper extremity injuries were associated with a reduced risk (OR 0.43 (95%CI 0.24–0.75), p=0.003) of moderate/severe pain 6 months post injury. Age (p=0.98), gender (p=0.37) and the presence of multiple orthopaedic (p=0.76) or non-orthopaedic injuries (p=0.58) were not predictors of moderate/severe pain 6 months post injury.

The severity of pain at discharge was the main predictor of moderate/severe pain 6 months following orthopaedic trauma. Further studies are needed to determine if improving pain control prior to discharge can reduce the incidence of persistent pain following orthopaedic injury.

Introduction Disc replacement surgery is being investigated as an alternative to spinal fusion surgery in the hope that maintaining segment spinal motion will not only relieve pain, but also prevent or reduce the likelihood of symptomatic adjacent segment degeneration that is believed to be a consequence of fusion surgery. The aim of this study was to identify evidence in the medical literature that indicates whether or not spinal fusion surgery increases the likelihood of symptomatic adjacent segment degeneration compared to disc replacement surgery or natural history.

Methods A search of the Cochrane Controlled Trials Register, Medline and reference lists of retrieved articles was performed. Search terms included arthroplasty replacement, spinal fusion, prognosis, controlled clinical trials and cohort studies, Studies were included if abstracts were available electronically, were published in the English language before1/3/2005 and involved humans. Levels of evidence were determined using the Oxford Centre for Evidence-Based Medicine criteria (http://www.cebm.net/levels of evidence.asp).

Discussion The majority of identified studies were case series of patients presenting with adjacent level disc degeneration following spinal fusion surgery (Level 4) and whilst indicating patients can develop adjacent level disc degeneration following fusion surgery, do not indicate the likelihood of doing so. Uncontrolled prospective cohort studies (Level 4) provide conflicting evidence. One retrospective cohort (Level 2b) studying comparing the incidence of adjacent disc degeneration following spinal fusion and discectomy or decompressive surgery alone found that the incidence of degeneration in the superior adjacent disc was increased in the fusion group, but was not associated with differences in functional outcome. No systematic reviews of inception cohort studies (Level 1) were identified.

Conclusions Only poor quality evidence has been published to support the proposition that spinal fusion surgery is associated with an increased likelihood of developing symptomatic adjacent level disc degeneration. Long term follow-up of patients enrolled in prospective randomised controlled trials comparing outcomes of spinal fusion and disc replacement surgery is necessary to determine whether or not disc replacement surgery decreases the likelihood of any symptomatic adjacent level disc degeneration that can be attributed to spinal fusion surgery.

Introduction Cervical disc replacement has been advocated as a technique for retaining segmental motion following discectomy. The in vivo kinematics of the prosthesis are predicted to influence outcome, but remain poorly understood. The aim of this study was to determine whether factors that might possibly influence outcome can be reliably measured.

Methods Anteroposterior and lateral xrays were performed pre-, inter- and post-operatively on 67 patients undergoing cervical prosthetic disc replacement. The xrays were reviewed by 3 observers. Measurements were performed manually by two observers and using digital image analysis software by a third observer.

The inter-rater reliability of categorical measurements such as overall cervical alignment, degree of disc degeneration and length of spinous processes was assessed using unweighted kappa scores. Intra-class correlation coefficients (ICCs) were calculated using a two-way random effects model to assess inter-rater agreement in the observation of continuous variables such as intra-operative disc angles, post-operative shell angles and change in focal lordosis. The intra-rater reliability of measurements of disc space angulation was calculated on a subset of 17 sets of xrays measured by three observers on two occassions, five months apart.

Kappa and ICC values were interpreted as recommended by Altman.

Results The inter-rater reliability of measuring the degree of disc degeneration (κ= 0.29 p< 0.0001) was fair and the spinous process length (κ = 0.79 p< 0.0001) and overall spinal alignment (κ = 0.69 p< 0.0001) good.

The inter-rater reliability of measuring pre-operative focal lordosis (ICC 0.88 (95%CI 0.82–0.92 p< 0.0001)), intra-operative disc angle (ICC 0.86 (95%CI 0.79–0.92) p< 0.0001) and post-operative shell angle (ICC 0.99 (95%CI 0.98–1.00) p< 0.0001) were excellent.

ICCs were higher when the average of the rater scores was considered. The ICCs were substantially reduced when agreement between the observers and values obtained using digital imaging was assessed.

The intra-rater reliability of measurements of focal lordosis however revealed good agreement when measured manually (ICC 0.68 (95%CI 0.06–0.89) p=0.02) but very good agreement when measured using digital imaging software (ICC 0.82 (95%CI 0.54–0.93) p< 0.0001). The inter-rater reliability of average disc space height when measured using digital imaging software was excellent (ICC 0.83 (95%CI 0.58–0.94) p< 0.0001).

Conclusions Whilst the reliability of determining the degree of disc degeneration in the cervical spine is fair, the measurement of focal lordosis, intra-operative disc angles and post-operative shell angle is good or excellent. As these radiological measures can be reliably assessed, they may be further evaluated as predictors of outcome following cervical disc replacement.

Introduction The early clinical results of cervical disc replacement surgery are encouraging but the in vivo kinematics of prostheses remains poorly understood. Two recent published reports suggest that use of a prosthesis with an unconstrained (over normal range of motion) biconvex nucleus (Bryan Cervical Disc® – Medtronic Sofamor Danek, Memphis, TN) can be associated with post-operative segmental kyphosis.

This study examines post-operative kyphosis and segmental imbalance following cervical disc replacement using the Bryan Cervical Disc prosthesis and factors which may influence this. In particular, the influence of change in disc space height as a result of surgery was studied.

Methods 67 patients underwent prosthetic disc replacement by one of three surgeons (19, 25 and 23 patients, respectively) using the Bryan prosthesis. 46 single, 20 double and 1 triple level were operated. Neutral pre- and post-op erect and intra-operative x-rays were examined manually and using digital image analysis software (Medical Metrics, Inc. Houston, TX). Possible contributing factors to segmental alignment were studied including: pre-op alignment, angle of prosthesis insertion, disc space degeneration and sacrifice of the posterior longitudinal ligament (PLL). Particular attention was given to changes in disc space height and factors which may influence this.

Inter- and intra-observer agreement was assessed. Non-parametric tests were used for assessment of categorical and skewed continuous variables. Multivariate linear regression was used to adjust significant correlation coefficients. Significance was set at p< 0.05.

Results The median pre-op focal lordosis of +0.5° (range: 21 to −14°, −ve = kyphotic) changed by −1° (+14 to −17°), to post-op: 0° (+11.5 to −16°).

There was a significant difference in the median change in focal lordosis for surgeon 1 (−3°) vs. surgeons 2 & 3 (−1°) (p< 0.005) and in the loss of disc space height. Median loss of disc space height for surgeon 1 was 22% vs. 8% for surgeons 2 & 3 (p< 0.002). Correlation co-efficient (Spearman) for change in disc space height vs. change in disc space angulation was 0.67 (p< 0.0001). No single pre- or intra-operative factor was found to clearly correlate with subsequent loss of disc space height apart from a trend towards a weak correlation with the angle of prosthesis insertion (r=0.24, p=0.06).

Discussion The median change (loss) in focal lordosis was −1.5° but there was considerable range: from +14° to −17°. Attempts to identify contributing factors suggest that a number may be involved but there did appear to be a highly significant correlation between loss of disc space height following surgery and subsequent focal kyphosis.

While the difference in outcomes between Surgeon 1 and Surgeons 2 & 3 is probably not clinically significant, it does suggest that intra-operative factors such as the angle of prosthesis insertion may be important. We are continuing to study these factors.

Introduction: Little is known about the epidemiology of spinal injuries in large major trauma populations. The aim of this study, therefore, is to describe mechanisms of injury, patient and injury characteristics and outcomes following spinal injuries in major trauma patients.

Methods: Data was extracted from the State Trauma Registry for Victoria (population 4.6 million) on all patients registered between 1 July 2001 and 31 June 2003 with spinal injuries and an Injury Severity Score (ISS) > 15. Injuries were defined using Abbreviated Injury Score (AIS) codes. Major trauma patients with spinal injuries were compared with those without spinal injuries with respect to age, gender, ISS scores, mechanism of injury, number and site of spinal and associated injuries, acute length of stay and discharge destination.

Results: 2194 major trauma patients were identified, of which 548 (25%) had spinal injuries. Spinal injuries occurred in 412 males (75%) and 136 females (25%), with a median age of 36 years (range 2–94 years). There was no difference in age or gender compared with patients with no spinal injury. 316 patients (58%) had multiple spinal injuries. 22% of patients with spinal injuries had associated spinal cord injuries. Most spinal fractures occurred and were more likely to occur as the result of motor vehicle (46%) or motorcycle (16%) crashes or falls from heights greater than 1 metre (15%).

The median ISS score was 24 (range 16–75) and not significantly different from patients with no spinal injury. The median number of associated injuries was 5 (range 0–23) and patients with spinal injuries were more likely to have associated thoracic, abdominal and extremity injuries and less likely to have associated head injuries than patients with no spinal injury. Patients with spinal injuries were more likely to be discharged to rehabilitation or convalescent hospitals and less likely to die than patients with no spinal injury.

Discussion: Spinal injuries are common and often multiple in major trauma patients and are associated with a greater need for rehabilitation. Further studies are required to determine the impact of spinal injuries on the functional outcomes of major trauma patients.

Introduction: Recently frameless stereotaxy has been introduced to assist with the spinal instrumentation. The mobility of individual vertebra however limits its accuracy and ease of use. The authors have developed a novel method of spinal stereotaxy using exact plastic copies of the spine manufactured using biomodelling technology.

Methods: Fifteen patients with complex spinal disorders requiring instrumentation were recruited. A 3D CT scan of their spine was performed and the data were transferred via DICOM network to a computer workstation. ANATOMICS BIOBUILD software was used to generate the code required to manufacture exact acrylate biomodels of each spine using rapid prototyping. The biomodels were used to obtain informed consent from patients and simulate surgery. Simulation was performed using a standard power drill to place trajectory pins in the appropriate pedicles. Acrylate drill guides were manufactured using the biomodels as templates. The biomodels and templates were sterilised and used intra-operatively to assist with the placement of the instrumentation.

Results: The biomodels were found to be highly accurate and of great assistance in the planning and execution of the surgery. The ability to drill optimum screw trajectories in the biomodel and then accurately replicate the trajectory was judged especially helpful. Accurate screw placement was confirmed with post-operative CT scanning. The design of the first two templates was suboptimal as the contact surface area was too great and complex. Approximately 20 minutes was spent pre-operatively preparing each biomodel and template. Operating time was reduced, as less reliance on intra-operative X-ray was necessary. Minimal invasive surgery was greatly facilitated in planning and execution. Patients stated that the biomodels improved informed consent.

Conclusion: Biomodel spinal stereotaxy is a simple and accurate technique which may have advantages over frameless stereotaxy.

Aims: To compare digital imaging sent via email versus conventional radiographs in diagnosing and managing ankle fractures. Methods: Radiographs on a viewing box were photographed using a digital camera with a resolution of 1024 x 768 pixels at 24-bit colour depth. The resultant images were compressed using the JPEG (Joint Photographic Experts Group) format at a medium compression ratio and transmitted as email attachments. The mean size of the resultant files was 165 kByte (range146–209). The study radiographs, including 66 radiographs (33 A-P and 33 Lateral), were viewed by seven orthopaedic surgeons and assessed according to the classification of ankle fracture and the surgeons’ choice of management for that fracture. Over a four month interval, each surgeon was independently shown each set of patients’ radiographs 4 times: twice via JPEG format on a computer screen and twice via a conventional light box. Results: Results were analysed using weight kappa scores, interclass correlation and variance, for interobserver and intraobserver error for both diagnostic classification and for management decision. These results were then used to determine if there was a difference between interpretation of radiographs presented in the two different formats. There were no significant difference in diagnostic accuracy or management decisions between conventional radiographs and telemedicine reading. Conclusions: JPEG compression is suitable for transmission of X-ray

Science is an endeavour built on facts. Scientific methods discover facts, which have force because they are believed to be directly observable and exist independently of theory. Facts so discovered, constitute the solid and reliable foundations of scientific knowledge. Science is objective and rational because it predicts and explains outcomes that are valid and reliable. Applying scientific methods to medical practice is therefore thought to protect medical decision making from arbitrariness, bias, and error.

Pain presents a particular challenge to physicians seeking to base their practice on science. Pain is defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. It is defined as subjective, because it is an internal phenomenon, not directly observable. It represents a quality, not a fact.

Tensions arise when scientific methods attempt to include subjective experiences within its objective framework. These tensions however, must be resolved if subjective phenomena, such as pain, are to be treated in a reliable and rational manner.

This paper presents a philosophical exploration of the tensions inherent in the study of subjective phenomena, such as pain, within an objective framework, based on contemporary models of rationality.

Introduction: Spinal infections are uncommon, but if the diagnosis is delayed or missed, serious consequences may occur. Recently, there have been major advances in diagnosis and treatment of spinal infections.

Aim: To document the evolving clinical picture, diagnosis and treatment of spinal infection over 20 years.

Methods: Prospective and retrospective data were collected by the infectious diseases services of a metropolitan referral centre and a provincial region. The clinical features, investigations, treatment and outcomes were analysed and comparisons were made between two periods; 1980–1992 and 1993–1999, and between the separate centres.

Results: One hundred and fifteen patients presented, with an estimated incidence of 1.7 cases/100,000/yr. The median age increased from 55 to 63.5 years and median time to diagnosis decreased from 28 to 21 days. The most common symptom was local back pain [112/115 (97%)] and the most common sign was local tenderness [88/115 (77%)]. A fever was present in 73/115 [63%]. Forty-one patients had neurological signs [36%] and 50 [43%] had epidural masses. MRI scanning was the most accurate imaging method. All patients received antimicrobial therapy, 27 [23%] partly through an at-home programme. Forty-nine patients [43%] required surgery. At follow-up, 76% were considered cured without neurological deficits. The outcomes improved over time and the differences between services reflected referral patterns.

Conclusions: Over the last 20 years the management of spinal infection has evolved through new diagnostic technology, prolonged treatment with antimicrobials, appropriate surgical intervention and a multidisciplinary approach. Heightened awareness of the condition is required to minimise the potentially serious consequences.