Quadriceps femoris muscle weakness has long been associated with disuse atrophy in symptomatic knee osteoarthritis but more recently implicated in the aetiology of this condition. The purpose of this study was to assess the benefits of two interventions aimed at increasing quadriceps strength in subjects with moderate to severe knee osteoarthritis. Twenty-eight patients, aged fifty-five to seventy-five, were recruited and randomised to either a six-week home resistance-training exercise program or a six-week neuromuscular electrical stimulation (NMES) program. Eleven patients matched for age, gender and osteoarthritis severity formed a control group, receiving standard care. The resistance-training group performed six exercises three times per week, while the NMES group used the garment stimulator for twenty minutes five times per week Outcome measures included isometric and isokinetic quadriceps strength, functional capacity, quadriceps cross-sectional area, and validated health survey scores. These measures were assessed at baseline, post-intervention and at 6-weeks post-intervention. Both intervention groups showed significant improvements in all functional tests, in the global health survey, and in quadriceps cross-sectional area immediately post-intervention. An increase in isokinetic strength was seen in the exercise group only. With the exception of isokinetic strength, all benefits were maintained six weeks post-intervention. Both a six-week home resistance-training program and a six-week NMES program produce significant improvements in functional performance as well as physical and mental health for patients with moderate to severe knee osteoarthritis. Home-based NMES is an acceptable alternative to physical therapy, and is especially appropriate for patients who have difficulty complying with an exercise program.
In a prospective randomised study we compared the results of arthroscopic subacromial bursectomy alone with debridement of the subacromial bursa followed by acromioplasty. A total of 57 patients with a mean age of 47 years (31 to 60) suffering from primary subacromial impingement without a rupture of the rotator cuff who had failed previous conservative treatment were entered into the trial. The type of acromion was classified according to Bigliani. Patients were assessed at follow-up using the Constant score, the simple shoulder test and visual analogue scores for pain and functional impairment. One patient was lost to follow-up. At a mean follow-up of 2.5 years (1 to 5) both bursectomy and acromioplasty gave good clinical results. No statistically significant differences were found between the two treatments. The type of acromion and severity of symptoms had a greater influence on the clinical outcome than the type of treatment. As a result, we believe that primary subacromial impingement syndrome is largely an intrinsic degenerative condition rather than an extrinsic mechanical disorder.
We report our experience with a new technique for cryosurgical ablation of bone tumours which allows accurate determination of the temperature and freezing time within a cavity of any geometrical shape. Between 1997 and 2000, 58 patients diagnosed with 13 malignant and 45 aggressive benign bone tumours underwent argon-based cryoablation. This technique includes removal of the tumour by curettage and filling the cavity with a gel medium into which metal probes are inserted. Argon gas is delivered through the metal probes and both time and temperature are computer-controlled. After formal reconstruction, all patients were followed for more than two years. None had skin necrosis, infection, neurapraxia or thromboembolic complication. Fractures occurred in two patients (3.4%) and the tumour recurred in two patients (3.4%).
We have studied 105 patients with 107 acute, primary, dislocations of the glenohumeral joint seen between January 1, 1991 and July 1, 1994. The mean time of follow-up was 71 months (46 to 91). In 34% the injury occurred during a sports activity and in 28% at home. The bias toward sport was even greater in patients less than 40 years of age, and in men. In patients older than 40 years of age, and in women, the dislocation occurred more often at home. The overall probability of recurrence within four years was 26%. Age was the most significant prognostic factor in recurrence which took place in 64% of patients less than 20 years of age and in 6% of those older than 40 years. Statistically, there was no difference between the rates of recurrence in patients who were active in sport and those who were not. The mean Rowe score for the whole group was 87 (15 to 100). Associated fractures were found in 20 patients (19%) and nerve injuries in 22 (21%). None of those in whom a fracture of the greater tuberosity was seen subsequently suffered a recurrent dislocation. At follow-up we found that 36 patients (34%) had not returned to their former employment but in only 2% was this owing to the injured shoulder.
To investigate the responsiveness to change of four different elbow-scoring instruments, two Hospital for Special Surgery (HSS) elbow assessment scales, the Mayo Clinic elbow-performance index (Mayo) and the Elbow Functional Assessment (EFA) scale.
A group of 24 RA patients (median age 60 years) undergoing either elbow arthroplasty (22 elbows) or synovectomy with radial head excision (3 elbows), were evaluated both prior and after surgery (median: seven months postoperatively). Score changes, obtained by using the scales under study, were calculated. The patient’s opinion of global perceived effect of the intervention was used as a criterion to classify them as ‘improved’ or ‘non-changed’. Responsiveness was evaluated with use of three approaches: using paired t-statistics (pre- and post-surgery scores), effect size statistics (standardized response mean, effect size and responsiveness ratios) and Receiver Operator Characteristic (ROC) curves.
Each of the elbow rating measures under study proved to be responsive to change when evaluating RA patients undergoing elbow arthroplasty or synovectomy. The EFA scale demonstrated the highest power to detect a clinically meaningful difference and had the best discriminative ability to distinguish improved from non-changed patients, as was revealed by all responsiveness statistics applied.
The HSS, the Mayo and the EFA elbow-scoring scales can all be used as an evaluative instrument to assess the efficacy of surgical treatment of the rheumatoid elbow joint. However, using the EFA scale will require smaller sample sizes to achieve a fixed level of statistical power than the other scales under study.
Chondrocyte sensitivity to strain depends on signal transduction pathways which include integrin-dependent increases in intracellular calcium. Human articular chondrocytes were cultured as monolayers in silicone dishes. After loading the cells with the calcium-fluorescent dye Fluo-3/AM the dishes were mounted in a 4-point bending apparatus and then fixed to a laser scanning confocal microscope. Biaxial substrate strain (15 000e) was applied to the silicone dish via a hand operated cam rotated at ~60 RPM (1 Hz) for 10 or for 50 cycles. Changes in intracellular calcium in single cells were determined by measuring the mean pixel values in the basal and stimulated images taken at different time points. The data reported for 50 cycle treatments represent 49 single cells of six independent cell isolations. The data for 10 cycle strain treatment are from a single experimental setup. Increases in intracellular calcium were consistently observed in chondrocytes exposed to 15 000me for 50 cycles in a range from 1.3- to 4.0-fold with an average of 2.3-fold (SD=0.79). Few cells responded before 30 minutes but most of the responses occurred 30–60 minutes after strain. Consistent intracellular Ca++-increases were also seen after 10 strain cycles, however responses were detected within 5 minutes post-strain. The relative increase (2.7-fold ± 1.7) was similar in magnitude to 50 cycle responses. Intracellular Ca++-fluxes in chondrocytes and other cells occur by at least two different mechanisms: through stretch-activated channels in the plasma membrane permit immediate Ca++-influx during strain application or by Ca++-efflux from intracellular compartments stimulated by slower acting second messengers. Our results suggest that the early response to 10 strain cycles is due to Ca++-influx via membrane channels while the later response to 50 cycles is due to Ca++-efflux from intracellular compartments, probably mediated by cytokines released in response to an initial Ca++-influx from the medium.
Opinion varies as to the incidence of nerve lesions in anterior dislocation of the shoulder after low-velocity trauma. Most studies are retrospective or do not use EMG. We have investigated the incidence and the clinical consequences of nerve lesions in a prospective study by clinical and electrophysiological examination. Axonal loss was seen in 48% of 77 patients. The axillary nerve was most frequently involved (42%). Although recovery as judged by EMG and muscle strength was almost complete, function of the shoulder was significantly impaired in patients with lesions of the axillary and suprascapular nerves. Unfavourable prognostic factors are increasing age and the presence of a haematoma. It is not necessary to carry out EMG routinely; an adequate programme of physiotherapy is important. In patients with a severe paresis, EMG is essential after three weeks.
We analysed the bacterial contamination of 1999 bone allografts retrieved from 200 cadaver donors under sterile operating conditions. The effect of various factors on the relative risk of contamination was estimated using a multiple logistic regression model. Organisms of low pathogenicity were cultured from 50% of the grafts and of high pathogenicity from 3%. The risk of contamination with low pathogenic organisms (mainly skin commensals) increased by a factor of 1.6 for each member added to the procurement team. The risk of contamination with high pathogenic organisms (mainly contaminants from the gastrointestinal tract) was 3.4 times higher in donors with a traumatic cause of death and 5.2 times higher in those with a positive blood culture. Preceding organ procurement did not significantly influence the risk of contamination. Rinsing the graft with an antibiotic solution was not an effective decontamination method. The major source of contamination is exogenous and is strongly influenced by the procurement team. Contamination from endogenous sources can be controlled by donor selection. We discuss methods that can be used to decrease contamination and the rate of discarding of bone allografts.
