Static postural sway, proprioception, and maximal voluntary quadriceps contraction in patients with knee osteoarthritis and normal control subjects

OBJECTIVES: To investigate whether subjects with knee osteoarthritis (OA) have reduced static postural control, knee proprioceptive acuity, and maximal voluntary contraction (MVC) of the quadriceps compared with normal controls, and to determine possible independent predictors of static postural sway. METHODS: 77 subjects with symptomatic and radiographic knee OA (58 women, 19 men; mean age 63.4 years, range 36-82) and 63 controls with asymptomatic and clinically normal knees (45 women, 18 men; mean age 63 years, range 46-85) underwent assessment of static postural sway. 108 subjects (59 patients, 49 controls) also underwent assessment of knee proprioceptive activity and MVC (including calculation of quadriceps activation). In patients with knee OA knee pain, stiffness, and functional disability were assessed using the WOMAC Index. The height (m) and weight (kg) of all subjects was assessed. RESULTS: Compared with controls, patients with knee OA were heavier (mean difference 15.3 kg, p<0.001), had increased postural lateral sway (controls: median 2.3, interquartile (IQ) range 1.8-2.9; patients: median 4.7, IQ range 1.9-4.7, p<0.001), reduced proprioceptive acuity (controls: mean 7.9, 95% CI 6.9 to 8.9; patients: mean 12.0, 95% CI 10.5 to 13.6, p<0.001), weaker quadriceps strength (controls: mean 22.5, 95% CI 19.9 to 24.6; patients: mean 14.7, 95% CI 12.5 to 16.9, p<0.001), and less percentage activation of quadriceps (controls: mean 87.4, 95% CI 80.7 to 94.2; patients: mean 66.0, 95% CI 58.8 to 73.2, p<0.001). The significant predictors of postural sway were knee pain and the ratio of MVC/body weight. CONCLUSIONS: Compared with age and sex matched controls, subjects with symptomatic knee OA have quadriceps weakness, reduced knee proprioception, and increased postural sway. Pain and muscle strength may particularly influence postural sway. The interaction between physiological, structural, and functional abnormalities in knee OA deserves further study.     

Living cytology: A new diagnostic technique for malignant pleural effusions.

The efficacy of a new tissue-culture technique for the diagnosis of malignant pleural effusions was contrasted with conventional cytologic methods. The new technique is based on the ability of the tissue-culture medium to transform mesothelial cells into fibroblasts while not sustaining lymphoreticular cells. Against a background of fibroblasts, islets of adenocarcinoma are easily identified. Of 20 patients with pleural effusions and solid tumors, the tissue-culture technique correctly diagnosed eight (40 percent), compated to seven (35 percent) for conventional cytologic methods. Of 27 pleural effusions in patients without malignant neoplasms, there was only one probable false-positive.     

A simple technique for detecting small defects of the atrial septum

A sensitive technique for detecting small defects of the atrial septum is described. A Valsalva maneuver is used to cause right atrial pressure to exceed left atrial pressure. This reversal of the normal interatrial pressure gradient causes a transient right to left shunt across the defect. The right to left shunt is detected by noting an early appearance deflection in standard indicator-dilution curves performed by injecting indocyanine green dye into the inferior vena cava during the Valsalva maneuver. By means of this technique, 7 of 8 surgically induced defects, from 1 to 12 mm in diameter, were detected. There were no false positive results among 9 control animals with an intact atrial septum. This technique presents a sensitive and simple method for detecting small atrial septal defects. The only equipment required is that used to perform standard indicator-dilution curves.     

The association of quadriceps strength with the knee adduction moment in medial knee osteoarthritis

Objective

To investigate the relationship between quadriceps strength and the peak knee adduction moment during walking in medial tibiofemoral osteoarthritis (OA), and whether varus malalignment influences this relationship.

Methods

Maximum isometric quadriceps strength at 60° flexion relative to body mass and the peak knee adduction moment during walking were assessed in 184 community volunteers with medial knee OA. Mechanical knee alignment was determined either directly from full‐leg radiograph or extrapolated from anatomic alignment on knee radiograph using regression equations. Pearson's correlation coefficient was used to assess the association between quadriceps strength and peak knee adduction moment. The independent relationship between quadriceps strength and peak knee adduction moment, and the impact of varus malalignment on this relationship, was assessed using multiple regression analyses with and without adjustment for covariates.

Results

Quadriceps strength was not significantly associated with peak knee adduction moment (r = 0.14, P = 0.059). Neither quadriceps strength (b = 0.25, P = 0.142) nor the interaction between quadriceps strength and varus malalignment (b = ?0.01, P = 0.693) significantly contributed to the variance in peak knee adduction moment. Results were unchanged with the inclusion of covariates.

Conclusion

No significant association was observed between quadriceps strength and the peak knee adduction moment, and the severity of varus malalignment did not influence the relationship. Results suggest that clinicians should not be concerned that patients with knee OA and stronger quadriceps are more likely to demonstrate a higher knee adduction moment.

     

The effect of isometric quadriceps strength training in mid-range for osteoarthritis of the knee

This case report describes the effect of strengthening the quadriceps of an effused osteoarthritic knee joint of a 53-year-old man isometrically in mid-range. The instruments included an isokinetic dynamometer, a knee scoring inventory, and a visual analog scale. The outcomemeasures of isometric quadriceps torque and work, clinical status, and pain were recorded before andafter the exercise intervention. The exercises were carried out three times per week for a 6-week period with the subject seated on an exercise chair. Following training, quadriceps torque increased, clinical status improved, and pain with walking decreased. Subject to further investigation, isometric training of the quadriceps in mid-range could prove useful for improving the function of persons with painful or effused knees who might otherwise experience muscle inhibition by exercising in the more traditional inner ranges of knee extension.     

Ultrasound imaging for the rheumatologist IV. Ultrasonography of the knee

Ultrasound examination of the knee is particularly useful in the detection of synovitis, early degenerative changes within the articular cartilage of the femoral condyles, calcifications within the articular cartilage layer and menisci, bursitis, and popliteal cysts. Also, important anatomical information about the structural integrity of the supporting tissues around the knee can be obtained by ultrasound in patients presenting with 'knee pain'. We review the available evidence about the use of ultrasound in knee examination, provide information on the technical equipment and scanning methods and discuss the still controversial issues.     

A home-based protocol of electrical muscle stimulation for quadriceps muscle strength in older adults with osteoarthritis of the knee

OBJECTIVE: To determine whether home-based neuromuscular electrical stimulation (NMES) applied to the quadriceps femoris (QF) muscle increases strength, physical activity, and physical performance in older adults with knee osteoarthritis (OA). METHODS: Thirty-four adults (> 60 yrs) with radiographically confirmed symptomatic knee OA were randomized to NMES plus education or education only (EDU). The primary outcome was isometric QF peak torque (PTIso), with secondary outcomes of daily step counts, total activity vector magnitude, 100-foot walk-turn-walk, timed stair climb, chair rise, and pain. The NMES group used a portable electrical muscle stimulator 3 days a week for unilateral QF training with incremental increases in the intensity of isometric contraction to 30-40% of maximum over 12 weeks. Both groups received the 12-week Arthritis Self-Management course and were followed an additional 12 weeks. RESULTS: The stimulated knee-extensor showed a 9.1% increase in 120 degrees PTIso compared to a 7% loss in the EDU group (time x group interaction for 120 degrees PTIso; p = 0.04). The chair rise time decreased by 11% in the NMES group, whereas the EDU group saw a 7% reduction (p = 0.01, time; p = 0.9, group). Similarly, both groups improved their walk time by approximately 7% (p = 0.02, time; p = 0.61 group). Severity of pain reported following intervention did not differ between groups. CONCLUSION: In older adults with knee OA, a home-based NMES protocol appears to be a promising therapy for increasing QF strength in adults with knee OA without exacerbating painful symptoms.     

''MYNI''s orthosis'': a self-adjustable, dynamic knee extension orthosis for quadriceps weakness in haemophilia rehabilitation

In developing countries like India, where walking is the primary, preferred and feasible mode of transport, the implications following quadriceps weakness poses a serious threat to ones functional independence. This has been a challenge for professionals while ambulating individuals with haemophilia, where quadriceps weakness is very common. Although external splinting has been understood for many years, as a means of support in haemophilia, there is still a dearth of knowledge in making an appropriate splint to assist or to take over the weak quadriceps during ambulation. This newly designed 'MYNI's orthosis' helps in versatile ways in addition to assisting the weak quadriceps. It provides prolonged stretch to contracted tissue, allows for being used as a serial cast in improving the knee range and is cosmetically acceptable. Above all, it is user-friendly, thus enhancing compliance and superior outcome in haemophilic knee rehabilitation.     

The age-related slowing of voluntary shortening velocity exacerbates power loss during repeated fast knee extensions

Older adults are less fatigable than young during isometric tasks, but this apparent ability to resist fatigue is often abolished when dynamic actions are performed. These findings could indicate that the velocity component of dynamic contractions or the task performed is an important factor in explaining fatigability of older adults. However, it has not been evaluated systematically. The purpose was to investigate the differences in age-related fatigue of the knee extensors in 8 older (73.6 ± 3.5 years) and 8 younger (25.1 ± 2.6 years) men. Neuromuscular measures were collected at baseline, during and immediately following task termination of three different maximal effort knee extension tasks. On three separate days, participants performed either 30 slow (1.05 rad·s^− 1, 60°·s^− 1) or 30 moderate (3.14 rad·s^− 1, 180°·s^− 1) isovelocity contractions, or 30 fast unconstrained velocity contractions with a fixed resistance (i.e., 20% maximal voluntary isometric contraction). At baseline, the older men were 25% and 35% less powerful than the younger men for the slow and moderate isovelocity tasks, respectively, but 42% less for the fast unconstrained velocity protocol. At task termination for the slow (old: 53%, young: 53%) and moderate (old: 45%, young: 38%) isovelocity fatigue tasks, power was reduced similarly in both age groups. However, for the fast unconstrained velocity task, power was reduced by a greater extent in older (35%) than the younger men (23%) at task termination. These results highlight that age-related impairments in voluntary shortening velocity exacerbate reductions in power production during repetitive dynamic tasks. Furthermore, the importance of this factor is masked when velocity is constrained (isovelocity) and fatigue is dependent primarily upon slow torque generation.     

Aberrations in the control of quadriceps muscle force in patients with knee osteoarthritis

OBJECTIVE: To characterize the distribution of error in knee joint proprioception, quadriceps force accuracy and steadiness, and muscle strength in patients with knee osteoarthritis (OA). Special attention was paid to eccentric strength. METHODS: We compared knee OA patients (n=20: 15 women, 5 men) with age- and sex-matched, symptom-free adults. Knee pain and mobility were assessed with standard tests. Knee joint proprioception was measured with a repositioning test. Quadriceps force accuracy and steadiness were determined during a force target-tracking task. Maximal voluntary quadriceps force was measured during eccentric, isometric, and concentric contractions. RESULTS: OA patients had knee pain, needed 67% more time to complete 4 functional tasks, and produced 82% more proprioception errors (all P < 0.05). About 80% of this error was due to overshooting the target and 68% of the overshooting error occurred at 2 of the 5 least flexed knee joint positions. OA patients had 89% more errors in accurately matching target forces during submaximal quadriceps contractions and in the same tasks, OA patients also produced these forces with 155% more variability (all P < 0.05). OA patients had especially weakened ability to produce maximal voluntary eccentric strength. CONCLUSION: Quadriceps dysfunction in knee OA includes impaired proprioception, especially in the more extended knee joint positions; impaired ability to accurately and steadily control submaximal force; and impaired eccentric strength. These results have implications for designing exercise and rehabilitation programs for patients with knee OA.     

Evaluation of an immunological test for detecting occult fecal blood for case-finding in colorectal tumors

Screening for colorectal tumours (cancers and polyps) by searching for blood in stools using the gaiac test is a well-known method. We evaluated a new gaiac test, the originality of which from its coupling with an enzyme immuno-assay specifically measuring human hemoglobin (Fecatest). The objectives of this new test were to decrease false positives and thus to improve the positive predictive value of screening. Subjects over 45 years of age attending health examinations at a Center of Preventive Medicine were studied. Of the 5,185 subjects who received the test, 4,376 (84 p. 100) performed it correctly, demonstrating good compliance in this population. For 664 (15 p. 100), the results of the gaiac test were positive. This positivity rate was higher for men than for women (20 p. 100 vs. 10 p. 100) but was not influenced by age. After positive results, 471 (70 p. 100) patients completed investigations decreasing the overall compliance to 80 p. 100. Fifteen cases of cancer and 78 cases of adenomas were found. The positive predictive value of the test was 20 p. 100 for tumours. A benign cause was found in 44 p. 100 of 471 patients, and investigations were negative in 36 p. 100. When the gaiac test was positive, the immunoenzymatic method significantly improved the positive predictive value for cancer (6 p. 100 vs. 3 p. 100) but not for polyps (20 p. 100 vs. 17 p. 100). Three of the 15 cancers and half of the 78 adenomas would not have been discovered with the immunoenzymatic method.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ultrasound imaging for the rheumatologist XXX. Sonographic assessment of the painful knee

The knee joint is a frequent focus of attention for rheumatologists when assessing patients presenting to a clinic and may represent underlying intra-articular inflammatory pathology or involvement of the surrounding soft tissues. This study describes the correlation between clinical and ultrasound findings in patients presenting with a variety of rheumatic disorders and knee pain. US imaging provides for a sensitive and detailed identification of different intra- and peri-articular pathology responsible for knee pain.     

Implications of evaluating leg muscle mass and fat mass separately for quadriceps strength in knee osteoarthritis: the SPSS-OK study

Clinical Rheumatology - To examine the influence of obesity on quadriceps strength by separately analyzing body mass index (BMI) as fat mass and leg muscle mass in patients with knee osteoarthritis...     

Should synovectomy be performed during total knee arthroplasty for knee osteoarthritis: A protocol for systematic review and meta-analysis

Background:To evaluate the effect of synovectomy performed during primary total knee arthroplasty for knee osteoarthritis on patients’ postoperative pain and knee function.Methods:We will search the following electronic databases from inception to June 2021, including PubMed, EMBASE, Web of Science, the Cochrane Library, the China National Knowledge Infrastructure, the Chinese Scientific Journals Database, the Wanfang database, and the Chinese Biomedicine Database. Eligible references will be all randomized controlled trials of initial total knee arthroplasty for primary knee osteoarthritis with or without synovectomy. Two reviewers will independently extract the data. Reviewer Manager 5.3 software will be used for statistical analysis.Result:It will provide results on the short- and long-term efficacy and safety of synovectomy in total knee arthroplasty by various comprehensive assessments.Conclusion:This study will provide solid evidence on whether and when synovectomy treatment should be performed during total knee arthroplasty.     

A technique for detecting matrix proteins in the crystalline spicule of the sea urchin embryo.

The presence of proteins associated with the CaCO3-containing biocrystals found in a wide variety of marine organisms is well established. In these organisms, including the primitive skeleton (spicule) of the sea urchin embryo, the structural and functional role of these proteins either in the biomineralization process or in control of the structural features of the biocrystals is unclear. Recently, one of the matrix proteins of the sea urchin spicule, SM 30, has been shown to contain a carbohydrate chain (the 1223 epitope) that has been implicated in the process whereby Ca2+ is deposited as CaCo3. Because an understanding of the localization of this protein, as well as other proteins found within the spicule, is central to understanding their function, we undertook to develop methods to localize spicule matrix proteins in intact spicules, using immunogold techniques and scanning electron microscopy. Gold particles indicative of this matrix glycoprotein could not be detected on the surface of spicules that had been isolated from embryo homogenates and treated with alkaline hypochlorite to remove any associated membranous material. However, when isolated spicules were etched for 2 min with dilute acetic acid (10 mM) to expose more internal regions of the crystal, SM 30 and perhaps other proteins bearing the 1223 carbohydrate epitope were detected in the calcite matrix. These results, indicating that these two antigens are widely distributed in the spicule, suggest that this technique should be applicable to any matrix protein for which antibodies are available.