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Biomedical subjects

I Arvidsson

Publications and source records attributed to I Arvidsson.

29 records · Page 2Linked to original sources
PubMed1987

Changes in elemental composition of human muscle fibres following surgery and immobilization. An X-ray microanalytical study.

X-ray microanalysis of single muscle fibres visualized in the electron microscope has been applied to human muscle biopsies to quantify changes of intracellular elements after knee-surgery with subsequent immobilization for 6 weeks. An increase of intracellular chlorine (Cl; P less than 0.001) and of sodium (Na; P less than 0.1) concentrations were found 1 and 6 weeks post-surgery. Intracellular potassium (K), phosphorus and sulphur concentrations were not significantly changed. The increased Cl and Na concentrations may be an indication of a decreased activity of the ATPase-dependent Na/K-pump in the sarcolemma and/or of an increased sarcolemmal permeability for Na and Cl.

Adult↗
PubMed1987

A double blind trial of NSAID versus placebo during rehabilitation.

Forty patients participated in a randomized, parallel, double blind study of piroxicam, 20 mg daily, versus placebo, given orally for 10 days following open partial meniscectomy. On day 1, 3, 7, 11, and 21 after surgery the following parameters were studied: quadriceps torque measured isokinetically; patients' assessment of pain; active and passive range of motion measured with goniometer; degree of swelling and irritation of the operated knee; and efficacy of the medication. The mean values for all parameters, except for pain assessment, were in favor of the piroxicam group. This difference was most marked on day 7 and 11 and on these days highly significant. Our findings indicate that piroxicam may be able to improve early postoperative rehabilitation.

Adolescent↗
PubMed1986

Diagnostic and operative arthroscopy of the hip.

Diagnostic and operative arthroscopies of the hip joint have been performed from an anterior approach after extension of the joint. The force needed to achieve a sufficient visualization of the hip joint was studied. In an anesthetized patient 300 Newtons (N) to 500 N was required, whereas up to 900 N was needed in an unanesthetized subject to achieve sufficient joint extension. Hip arthroscopy has been performed with a standard 5 mm Storz arthroscope. Alternatively, fluid and gas was used. It was possible to achieve good visualization of the anterior parts of the hip. Gas gave better information about the degree of degenerative arthritis while fluid was preferable for operative arthroscopy, eg, arthroscopic synovectomy. Synovial biopsies, removal of loose bodies, and partial arthroscopic synovectomy have been performed. The advantage was a very short time of rehabilitation. No serious complications occurred.

Adult↗
PubMed1986

Postoperative TENS pain relief after knee surgery: objective evaluation.

A comparison was made between the pain-relieving effect of placebo-transcutaneous electrical nerve stimulation (TENS), high frequency TENS, and epidural analgesia with dilute local anesthetics in 15 patients with open knee surgery. Assessment of pain was compared with the patients' ability to contract their quadriceps muscle; the ability was measured with integrated EMG (IEMG) before and after the different treatments. The results showed that placebo-TENS had no significant effect on either pain perception or on IEMG. High frequency TENS given for 15 min to 20 min decreased pain perception by 50% at rest and by 11% after quadriceps contraction. High frequency TENS increased muscle contraction ability by 305%, compared with the initial contraction before treatment. Epidural injection of a dilute local anesthetic decreased pain perception by 90% at rest and by 67% after contraction, and increased muscle contraction ability by 1,846%. TENS undoubtedly has a place in the postoperative pain treatment, although its effect is not as strong as that of epidural analgesia with local anesthetics. TENS, however, is easy to administer, lacks side effects, and can be administered by the patients themselves.

Adult↗
PubMed1986

Reduction of pain inhibition on voluntary muscle activation by epidural analgesia.

The influence of postoperative pain on muscle function, and the possible effect of local anesthetics on the normal muscle function are discussed. The integrated EMG (IEMG) during maximum voluntary contraction of the quadriceps muscle was registered in ten patients the day after undergoing reconstruction of the anterior cruciate ligament. Recordings were taken before, 5, 12, and 20 min to 25 min after epidural injection of 20 ml of 0.25% lidocaine with adrenaline (2.5 micrograms/ml). As pain gradually subsided, IEMG increased a mean of 2,728% 20 min to 25 min after injection (range 425% to 10,068%), compared to initial recordings before anesthesia. This indicates that pain relief plays a significant role in the ability to normally activate the quadriceps muscle after open knee surgery. Neither the Hoffman (H-)reflex, nor maximum voluntary isokinetic muscle torque was appreciably affected by epidural injection of dilute local anesthetics, as tested on two healthy volunteers. Infiltrations of local anesthetics into the distal part of the quadriceps muscle did not affect maximum voluntary isokinetic knee extension torque. From the experiments performed we conclude that it is possible to selectively block pain by injections of local anesthetics into the epidural space, without interfering with normal muscle function. It might thus be possible to prevent some of the postoperative muscle atrophy by using a continuous epidural analgesia for two to three days following surgery, and starting an early active physical therapy program.

Adolescent↗
PubMed1986

Prevention of quadriceps wasting after immobilization: an evaluation of the effect of electrical stimulation.

Eighteen male and 20 female patients who underwent reconstruction of their anterior cruciate ligament (ACL) with a flap from the patellar tendon were randomly assigned into either closed cast, isometric muscle training and electric stimulation (ES group), or closed cast and isometric training alone (control group). The degree of quadriceps wasting was determined from computerized tomographic scans (CT) before and 6 weeks after surgery. Electrical stimulation was given with a battery operated stimulator that produced a rectangular asymmetric balanced biphasic pulse shape. The pulse rate was 40 Hz and the pulse width 300 microseconds. Patients received 30 min of stimulation three times daily during 5.5 weeks. Female control patients showed a larger decrease in quadriceps area on CT than male control patients (P less than .001). No significant difference was found between male electrically stimulated patients and control patients. In female patients, there was on the contrary, a highly significant difference in favor of electrical stimulation (P less than .001) When the different parts of the quadriceps were studied, a significantly lower degree of atrophy of the vastus medialis was found after electrical stimulation. Vastus lateralis did not show any difference. Measurements of CT attenuation, pre- and post-operatively, showed a decrease in attenuation of 17% for the vastus medialis and lateralis of the operated leg after immobilization, indicating an increase in fat content. In the rectus femoris, however, there was an increase in attenuation of 14.6%. Percutaneous muscle biopsies from the vastus lateralis obtained before, one week after, and 6 weeks after surgery revealed that the cross-sectional area of the individual muscle fibers decreased less in the electrically stimulated than in controls, but the difference was not significant. There were no differences between the two groups in the activity of an oxidative enzyme, citrate synthase, or a glycolytic enzyme, phosphofructokinase (PFK). We conclude that females reacted more favorably than males to electrical stimulation of quadriceps during an immobilization period after knee surgery.

Adult↗
PubMed1981

Isokinetic thigh muscle strength after ligament reconstruction in the knee joint: results from a 5-10 year follow-up after reconstructions of the anterior cruciate ligament in the knee joint.

We evaluated the thigh muscle strength using an isokinetic dynamometer in 80 patients 5 to 10 years following anterior cruciate ligament reconstruction. Patients with good results also had good muscle function, both of their flexor and their extensor muscles. Patients with poor results demonstrated reduced muscle strength in both their hamstrings and their quadriceps. Patients with fair functional results demonstrated reduced strength of their extensor muscles compared to their normal leg. However, strength in their operated leg's flexor muscles was unchanged compared to their normal leg. This may be due to the fact that strong hamstring muscles can compensate for some instability of the anterior cruciate ligament.

Adolescent↗
PubMedDate not supplied

Fluoride concentrations in saliva and dental plaque in young children after intake of fluoridated milk.

This study determined fluoride (F) concentrations in whole saliva and dental plaque after intake of fluoridated milk using a randomised crossover experimental design. Eighteen healthy children (6-8 years) were subjected to each of four different 3-day drinking regimens: (a) 200 ml F-free tap water; (b) 200 ml tap water with 1.0 mg F; (c) 200 ml standard milk, and (d) 200 ml standard milk with 1.0 mg F. A washout period of 7 days was organised between the different drinking regimens. All children used F-free toothpaste prior to and during the trial and were instructed to avoid F-rich food and drinks. F concentration in unstimulated whole saliva was determined at baseline and after 15 and 120 min and in plaque samples at baseline and after 2 h. The mean baseline values ranged from 0.01 to 0.02 mg F/l in saliva and between 10.4 and 14.2 mg F/l in dental plaque. A statistically significant (p < 0.05) increase of F was disclosed in saliva 15 min after drinking F-containing milk and water (0.052 and 0.058 mg F/l, respectively). After 2 h, the salivary F(-) concentrations were back to baseline values. In the plaque, however, a statistically significant (p < 0.01) twofold increase was found at 2 h after the intake of fluoridated milk and water, respectively. The results indicate that consumption of fluoridated milk contributes to a F storing process with significantly elevated F concentrations in dental plaque up to 2 h after intake. Further studies are required to determine the 'therapeutic concentration' of F in dental plaque after intake of fluoridated milk.

Animals↗
PubMedDate not supplied

The biomechanics of anterior cruciate ligament rehabilitation and reconstruction.

The rehabilitation of knee injuries involving the anterior cruciate ligament (ACL) is controversial. This paper describes strain in the normal and reconstructed ACL during a series of passive and active tests of knee flexion with and without varus, valgus, and axial rotation torques on the tibia. Strain in the human knee ACL was significantly different depending on whether the knee flexion angle was changed passively or via simulated quadriceps contraction. The knee joint capsule was found to be important for strain protection of the ACL. Quadriceps activity did not strain the normal or reconstructed ACL when the knee was flexed beyond 60 degrees, but significantly strained the tissue from 0 to 45 degrees of knee flexion. Immobilization may not protect the ACL if isometric quadriceps contractions are allowed to occur. Properly placed reconstructions exhibited strain behavior which closely followed the anteromedial band of the ACL.

Adult↗