A prospective assessment of SRS-24 scores after endoscopic anterior instrumentation for scoliosis

Study Design. Prospective clinical case series. Objective. To evaluate the clinical outcome of anterior endoscopic instrumention for scoliosis using the SRS-24 questionnaire and to examine how these scores change over a 2-year follow-up period. Summary of Background Data. Anterior endoscopic instrumentation correction has several advantages compared with open procedures. However, the clinical results of this technique using a validated outcome measure have rarely been reported in the literature. Methods. A total of 83 consecutive patients underwent endoscopic anterior instrumentation performed at a single unit. Patients completed the SRS-24 questionnaire before surgery and at 3, 6, 12, and 24 months after surgery. The SRS-24 scores were compared between each of the follow-up intervals. Results. The pain, general self-image, and function from back condition domains improved after surgery (P < 0.05). Activity level significantly improved between 3 and 6 months, and both function domains improved between 6 and 12 months (P < 0.05). None of the domains increased significantly after 1 year. Conclusions. Endoscopic anterior instrumentation for scoliosis significantly improved pain, self-image, and function. The greatest improvement in function occurred between 6 and 12 months after surgery. The SRS-24 scores at 1 year from surgery may provide a good indicator of patient outcome in the long-term.

OMERACT-OARSI Initiative: Osteoarthritis Research Society International set of responder criteria for osteoarthritis clinical trials revisited.

Background: The OARSI Standing Committee for Clinical Trials Response Criteria Initiative had developed two sets of responder criteria to present the results of changes after treatment in three symptomatic domains (pain, function, and patient's global assessment) as a single variable for clinical trials (1). For each domain, a response was defined by both a relative and an absolute change, with different cut-offs with regard to the drug, the route of administration and the OA localization. Objective: To propose a simplified set of responder criteria with a similar cut-off, whatever the drug, the route or the OA localization. Methods: Data driven approach: (1) Two databases were considered The 'elaboration' database with which the formal OARSI sets of responder criteria were elaborated and The 'revisit' database. (2) Six different scenarios were evaluated: The two formal OARSI sets of criteria Four proposed scenarios of simplified sets of criteria Data from clinical randomized blinded placebo controlled trials were used to evaluate the performances of the two formal scenarios with two different databases ('elaboration' versus 'revisit') and those of the four proposed simplified scenarios within the 'revisit' database. The placebo effect, active effect, treatment effect, and the required sample arm size to obtain the placebo effect and the active treatment effect observed were the performances evaluated for each of the six scenarios. Experts' opinion approach: Results were discussed among the participants of the OMERACT VI meeting, who voted to select the definite OMERACT-OARSI set of criteria (one of the six evaluated scenarios). Results: Data driven approach: Fourteen trials totaling 1886 CA patients and fifteen studies involving 8164 CA patients were evaluated in the 'elaboration' and the 'revisit' databases respectively. The variability of the performances observed in the 'revisit' database when using the different simplified scenarios was similar to that observed between the two databases ('elaboration' versus 'revisit') when using the formal scenarios. The treatment effect and the required sample arm size were similar for each set of criteria. Experts' opinion approach: According to the experts, these two previous performances were the most important of an optimal set of responder criteria. They chose the set of criteria considering both pain and function as evaluation domain and requiring an absolute change and a relative change from baseline to define a response, with similar cut-offs whatever the drug, the route of administration or the CA localization. Conclusion: This data driven and experts' opinion approach is the basis for proposing an optimal simplified set of responder criteria for CA clinical trials. Other studies, using other sets of CA patients, are required in order to further validate this proposed OMERACT - OARSI set of criteria. (C) 2004 OsteoArthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

The effectiveness of hylan G-F 20 in patients with knee osteoarthritis: an application of two sets of response criteria developed by the OARSI and one set developed by OMERACT-OARSI

Objective: Secondary analyses of a previously conducted 1-year randomized controlled trial were performed to assess the application of responder criteria in patients with knee osteoarthritis (OA) using different sets of responder criteria developed by the Osteoarthritis Research Society International (OARSI) (Propositions A and B) for intra-articular drugs and Outcome Measures in Arthritis Clinical Trials (OMERACT)-OARSI (Proposition D). Methods: Two hundred fifty-five patients with knee OA were randomized to appropriate care with hylan G-F 20 (AC + H) or appropriate care without hylan G-F 20 (AC). A patient was defined as a responder at month 12 based on change in Western Ontario and McMaster Universities Osteoarthritis Index pain and function (0-100 normalized scale) and patient global assessment of OA in the study knee (at least one-category improvement in very poor, poor, fair, good and very good). All propositions incorporate both minimum relative and absolute changes. Results: Results demonstrated that statistically significant differences in responders between treatment groups, in favor of hylan G-F 20, were detected for Proposition A (AC + H = 53.5%, AC = 25.2%), Proposition B (AC + H = 56.7%, AC = 32.3%) and Proposition D (AC + H = 66.9%, AC = 42.5%). The highest effectiveness in both treatment groups was observed with Proposition D, whereas Proposition A resulted in the lowest effectiveness in both treatment groups. The treatment group differences always exceeded the required 20% minimum clinically important difference between groups established a priori, and were 28.3%, 24.4% and 24.4% for Propositions A, B and D, respectively. Conclusion: This analysis provides evidence for the capacity of OARSI and OMERACT-OARSI responder criteria to detect clinically important statistically detectable differences between treatment groups. (C) 2004 OsteoArthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Two knees or not two knees? Patient costs and outcomes following bilateral and unilateral total knee joint replacement surgery for OA

Aims: This study aims to address medical and non-medical direct costs and health outcomes of bilateral and unilateral total knee replacement from the patients' perspective during the first year post-surgery. Methods: Osteoarthritis patients undergoing primary unilateral total knee or bilateral total knee replacement (TKR) surgery at three Sydney hospitals were eligible. Patients completed questionnaires pre-operatively to record expenses during the previous three months and health status immediately prior to surgery. Patients then maintained detailed prospective cost diaries and completed SF-36 and WOMAC Index each three months for the first post-operative year. Results: Pre-operatively, no significant differences in health status were found between patients undergoing unilateral TKR and bilateral TKR. Both unilateral and bilateral TKR patients showed improvements in pain, stiffness and function from pre-surgery to 12 months post-surgery. Patients who had bilateral TKR spent an average of 12.3 days in acute hospital and patients who had unilateral TKR 13.6 days. Totally uncemented prostheses were used in 6% of unilateral replacements and 48% of bilateral replacements. In hospital, patients who had bilateral TKR experienced significantly more complications, mainly thromboembolic, than patients who had unilateral TKR. Regression analysis showed that for every one point increase in the pre-operative SF-36 physical score (i.e. improving physical status) out-of-pocket costs decreased by 94%. Out-of-pocket costs for female patients were 3.3 times greater than for males. Conclusion: Patients undergoing bilateral TKR and unilateral TKR had a similar length of stay in hospital and similar out-of-pocket expenditures. Bilateral replacement patients reported better physical function and general health with fewer health care visits one year post procedure. Patients requiring bilateral TKR have some additional information to aid their decision making. While their risk of peri-operative complications is higher, they have an excellent chance of good health outcomes at 12 months and are not going to be doubly 'out-of-pocket' for the experience. (C) 2004 OsteoArthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Evaluation of WOMAC 20, 50, 70 response criteria in patients treated with hylan G-F 20 for knee osteoarthritis

Objective: A secondary analysis of a previously conducted one year randomised controlled trial to evaluate the capacity of responder criteria based on the WOMAC index to detect between treatment group differences. Methods: 255 patients with knee osteoarthritis were randomised to appropriate care with hylan G-F 20'' (AC+H) or appropriate care without hylan G-F 20'' (AC). In the original analysis, two definitions of patient response from baseline to month 12 were used: ( 1) at least a 20% reduction in WOMAC pain score ( WOMAC 20P); ( 2) at least a 20% reduction in WOMAC pain score and at least a 20% reduction in either WOMAC function or stiffness score ( WOMAC 20PFS). For this analysis, a responder was identified using 50% and 70% minimum clinically important response levels to investigate how increasing response affects the ability to detect treatment group differences. Results: The hylan G- F 20 group had numerically more responders using all patient responder criteria. Increasing the response level from 20% to 50% detected similar differences between treatment groups (25% to 29%). Increasing the response level to 70% reduced the differences between treatment groups (11% to 12%) to a point where the differences were not significant after Bonferroni adjustment. Conclusions: These results provide evidence for incorporating response levels ( WOMAC 50) in clinical trials. While differences at the highest threshold ( WOMAC 70) were not statistically detectable, an appropriately powered study may be capable of detecting differences even at this very high level of improvement.

Effectiveness and safety of repeat courses of hylan G-F 20 in patients with knee osteoarthritis

Objective: To compare the effectiveness and safety of repeat treatment with hylan G-F 20 based on data from a randomized, controlled trial [Raynauld JP, Torrance GW, Band PA, Goldsmith CH, Tugwell P, Walker V, et al. A prospective, randomized, pragmatic, health outcomes trial evaluating the incorporation of hylan G-F 20 into the treatment paradigm for patients with knee osteoarthritis (Part 1 of 2): clinical results. Osteoarthritis Cartilage 2002;10:506-17]. The hypotheses tested were whether the single-course and repeat-course subgroups would be superior to appropriate care and not different from each other. Method: A total of 255 patients with knee osteoarthritis were randomized to appropriate care with hylan G-F 20 or appropriate care without hylan G-F 20. The hylan G-F 20 group was partitioned into two subgroups: (1) patients who received a single course of hylan G-F 20; and (2) patients who received two or more courses of hylan G-F 20. Results: For the primary effectiveness measure, change in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score as a percent of baseline, the single-course subgroup improved by 41%, the repeat-course subgroup by 35%, and the appropriate care group by 14%. Both subgroups improved significantly more than the appropriate care group (P < 0.05), and were not statistically significantly different from each other (70% power to detect a 20% difference). Secondary effectiveness measures showed similar results. In the repeat-course subgroup, no statistically significant differences were found in the number of local adverse events, the number of patients with local adverse events, or arthrocentesis rates between the first and repeat courses of treatment. Conclusions: Although the study was neither designed nor powered to examine repeat treatment, this a posteriori analysis provides support for a favorable effectiveness and safety profile of hylan G-F 20 in repeat course patients. (C) 2004 OsteoArthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Performance of the Norwegian version of AUSCAN - a disease-specific measure of hand osteoarthritis

Objective: To examine the performance of the Norwegian version of the AUSCAN Index as a disease-specific health status measure in patients with hand osteoarthritis (OA). Methods: One hundred and ninety-nine patients with clinical hand OA (mean (SD) age 61.7 (5.7) years, 18 (9%) males) underwent a comprehensive examination including joint status, examination of grip strength and completion of several self-reported health status questionnaires. The Australian/Canadian OA hand index (AUSCAN) captures three different dimensions of hand OA: pain (5 items), stiffness (1 item), and difficulties with daily activities (9 items). Our pre-study hypothesis was to identify AUSCAN as a specific hand measure with strong correlations to hand measures and lower correlations to other general measures of health. Results: Patient completion of the AUSCAN Index was similar or better than other measures. The internal consistency of the AUSCAN was excellent. The pain and physical dimension of AUSCAN correlated substantially to, each other and moderately to the stiffness scale. The AUSCAN physical scale correlated moderately to substantially to other measures, the highest correlation being seen with the Arthritis Impact Measurement Scale (AIMS) 2 hand and finger function scale (r= 0.73). The standardised differences between patients with and without radiographic abnormalities were numerically larger for the AUSCAN pain and physical scales than for other measures. Conclusion: The Norwegian version of the AUSCAN has an acceptable clinimetric performance and is a suitable tool for assessment of hand OA. (C) 2005 OsteoArthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

The R8-BC8 phases and crystal growth in monocrystalline silicon under microindentation with a spherical indenter

The morphology and distribution of high-pressure metastable phases BC8 and R8, formed in monocrystalline silicon under microindentation, were identified and assessed using transmission electron microscopy nanodiffraction analysis. It was discovered that the crystal growth inside the transformation zone was stress-dependent with large crystals in its central region. The crystal size could also be increased using higher maximum indentation loads. The BC8 and R8 phases distributed unevenly across the transformation zone, with BC8 crystals mainly in the center of the zone and smaller R8 fragments in the peripheral regions. Such phase distribution was in agreement with the theoretical residual stress analysis.

Effects of experimentally-induced anterior knee pain on knee joint position sense in healthy individuals

Purpose. The ability to sense the position of limb segments is a highly specialised proprioceptive function important for control of movement. Abnormal knee proprioception has been found in association with several musculoskeletal pathologies but whether nociceptive Stimulation can produce these proprioceptive changes is unclear. This study evaluated the effect of experimentally induced knee pain on knee joint position sense (JPS) in healthy individuals. Study design. Repeated measures, within-subject design. Methods. Knee JPS was tested in 16 individuals with no history of knee pathology under three experimental conditions: baseline control, a distraction task and knee pain induced by injection of hypertonic saline into the infrapatellar fat pad. Knee JPS was measured using active ipsilateral limb matching responses at 20degrees and 60degrees flexion whilst non-weightbearing (NWB) and 20degrees flexion single leg stance. During the tasks, the subjective perception of distraction and severity of pain were measured using 11-point numerical rating scales. Results. Knee JPS was not altered by acute knee pain in any of the positions tested. The distraction task resulted in poorer concentration, greater JPS absolute errors at 20degrees NWB, and greater variability in errors during the WB tests. There were no significant correlations between levels of pain and changes in JPS errors. Changes in JPS with pain and distraction were inversely related to baseline knee JPS variable error in all test positions (r = -0.56 to -0.91) but less related to baseline absolute error. Conclusion. Knee JPS is reduced by an attention-demanding task but not by experimentally induced pain. (C) 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.

Cutaneous stimulation from patella tape causes a differential increase in vasti muscle activity in people with patellofemoral pain

Patella taping reduces pain ill individuals with patellofemoral pain (PFP), although the mechanism remains unclear. One possibility is that patella taping modifies vasti muscle activity via stimulation of cutaneous afferents. The aim of this study was to investigate the effect of stretching the skin over the patella on vasti Muscle activity in people with PFP. Electromyographic activity (EMG) of individual motor units in vastus medialis obliquus (VMO) was recorded via a needle electrode and from Surface electrodes placed over VMO and vastus lateralis (VL). A tape was applied to the skin directly over the patella and stretch was applied via the tape in three directions, while subjects maintained a gentle isometric knee extension effort at constant force. Recordings were made from five separate motor units in each direction. Stretch applied to the skin over the patella increased VMO surface EMG and was greatest with lateral stretch. There was no change in VL surface EMG activity. While there was no net increase in motor unit firing rate, it was increased in the majority of motor units during lateral stretch. Application of stretch to the skin over VMO via the tape can increase VMO activity, suggesting that cutaneous stimulation may be one mechanism by which patella taping produces a clinical effect. (c) 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.

A review of two journals found that articles using multivariable logistic regression frequently did not report commonly recommended assumptions

Background and Objective: To examine if commonly recommended assumptions for multivariable logistic regression are addressed in two major epidemiological journals. Methods: Ninety-nine articles from the Journal of Clinical Epidemiology and the American Journal of Epidemiology were surveyed for 10 criteria: six dealing with computation and four with reporting multivariable logistic regression results. Results: Three of the 10 criteria were addressed in 50% or more of the articles. Statistical significance testing or confidence intervals were reported in all articles. Methods for selecting independent variables were described in 82%, and specific procedures used to generate the models were discussed in 65%. Fewer than 50% of the articles indicated if interactions were tested or met the recommended events per independent variable ratio of 10: 1. Fewer than 20% of the articles described conformity to a linear gradient, examined collinearity, reported information on validation procedures, goodness-of-fit, discrimination statistics, or provided complete information on variable coding. There was no significant difference (P >.05) in the proportion of articles meeting the criteria across the two journals. Conclusion: Articles reviewed frequently did not report commonly recommended assumptions for using multivariable logistic regression. (C) 2004 Elsevier Inc. All rights reserved.

The nature of anterior knee pain following injection of hypertonic saline into the infrapatellar fat pad

The infrapatellar fat pad has been implicated as a possible source of anterior knee pain. This study examined the nature, distribution and time-course of experimentally induced pain in the infrapatellar fat pad. Hypertonic saline (5%) was injected into the medial fat pad of 11 healthy individuals with no history of knee pain. Severity of pain was assessed at rest and during activity using an 11 point numerical rating scale (NRS) at regular intervals over 15-30 min following injection. Participants described the size of the pain region from a series of different sized circles while the area and type of pain was established from a body chart and the McGill pain questionnaire. The effect of pain on temperature-pain threshold and sensory thresholds of the anterior knee was assessed. Participants generally reported a deep aching pain that peaked in severity around 3 min and gradually declined over 15 min. Pain levels were not altered by clinical manoeuvres designed to impinge the fat pad. The size of the pain region was related to pain intensity. Pain was most commonly felt in the region of the fat pad medial to the patella, although some individuals reported proximal referred pain as far as the groin region. Thermal and sensory thresholds were not altered at a region close to the injection site during the experimental pain. These results suggest that nociceptive stimulation of the infrapatellar fat pad may cause anterior knee pain that is not necessarily confined locally particularly if pain is severe. This has implications for the investigation of pathological structures in patients presenting clinically with anterior knee pain and provides an experimental model of anterior knee pain. (C) 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.