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Biomedical subjects

M Denti

Publications and source records attributed to M Denti.

At least 19 recordsLinked to original sources
PubMed2003

The role of the rehabilitation brace in restoring knee extension after anterior cruciate ligament reconstruction: a prospective controlled study.

To evaluate the effects of a rehabilitation brace locked in extension for the first week on the recovery of full extension after ACL reconstruction we compared two groups of subjects who underwent ACL bone-patellar tendon-bone reconstruction. The brace was unlocked twice a day for assisted physiotherapy. In Group A, 18 male subjects wore a post-operative brace locked from 0 degrees to 90 degrees. In Group B, 18 male subjects wore the same post-op brace locked in full extension for the first week. In both groups the brace was unlocked (0 degrees -120 degrees ) at the beginning of the second postoperative week, and then removed at the beginning of the third week. All the subjects followed the same rigorous, accelerated rehabilitation protocol. Each subject was evaluated pre and post-operatively (at second, fourth and eighth week) with bubble-level heel height difference (HHD) measurements and KT 1000 arthrometric assessment at the fourth postoperative month. Preoperative bubble-level HHD measurements of the two groups were statistically similar (Group A 0.6 cm, Group B 1 cm; not significant, n.s.). At the fourth week (Group A 2.2 cm, Group B 0.6 cm) and eighth week (Group A 1.6 cm, Group B 0.1 cm) follow-ups, bubble-level HHD measurements showed that the extension of the operated knees of Group B was significantly greater than in Group A. KT 1000 arthrometric scores showed no difference between the two groups (Group A 1.8 mm, Group B 1.5; n.s.).

Adult↗
PubMed2001

Replicating potato spindle tuber viroid RNA is accompanied by short RNA fragments that are characteristic of post-transcriptional gene silencing.

The low molecular weight fraction of tomato plants inoculated with potato spindle tuber viroid (PSTVd) contains a population of short PSTVd-specific RNAs of either polarity. The main constituents were RNAs of 22 and 23 nt representing different domains of the viroid genome. The occurrence of such distinct RNA species indicated that the nuclear replicating PSTVd RNA induces post-transcriptional gene silencing. The short RNAs were slightly more abundant at 30 days post-inoculation than at later stages and were present in plants infected with a mild, severe or lethal isolate of PSTVD: There was no apparent correlation between the quantity of small PSTVd-specific RNAs and the degree of virulence of the viroid isolate.

Blotting, Northern↗
PubMed2000

Motor control performance in the lower extremity: normals vs. anterior cruciate ligament reconstructed knees 5-8 years from the index surgery.

We compared motor control function in 50 patients who had undergone anterior cruciate ligament reconstruction using a bone-tendon-bone graft to that in 50 normal controls. Surgical subjects patients had undergone reconstruction with a one- (n=37) or two-incision (n=13) technique with the same rehabilitation protocol; mean time from the index surgery was 6.1 years (range of 5-8 years). For inclusion patients required an excellent outcome, category A IKDC score, and a KT-1000 side-to-side difference of 3 mm or less. Motor control evaluations were conducted using the KAT 2000 with static and dynamic tests. Normal controls had substantially better scores than did the surgical patients. There was no statistical difference the single-limb static test between scores of operated and nonoperated limbs. However, the operated limb scores were slightly better overall than those for the nonoperated limb, and the right knee scores tended to be better than those for the left knee. This may be explained by limb dominance. The test method employed in this investigation shows that anterior cruciate ligament reconstructed patients had a clear motor control deficit compared to normal control subjects even after several years.

Adult↗
PubMed1999

Sympathetic tone restrains arterial distensibility of healthy and atherosclerotic subjects.

BACKGROUND: Sympathetic activation induced by cold pressor test or cigarette smoking is accompanied by a marked reduction of radial artery distensibility. It is not known, however, whether arterial distensibility is under tonic sympathetic restraint, or whether this restraint involves arteries greater than the radial one in both normal and pathological conditions. METHODS: We studied the distensibility of radial artery by continuous ultrasonographic assessment of the changes in arterial diameter over the diasto-systolic pressure range (finger pressure measurement) in eight patients with a Dupuytren disease before and 20 min after ipsilateral brachial plexus anaesthesia. We also studied ultrasonographic distensibility of femoral artery in seven subjects before and 20 min after ipsilateral subarachnoid anaesthesia, performed before arthroscopic surgery, and in five patients with claudicatio intermittens before and 1 month after ipsilateral removal of the lumbar sympathectomy chain. In all three conditions, the contralateral artery served as control. RESULTS: The three interventions did not cause any significant alteration in blood pressure and heart rate. Radial artery distensibility was markedly increased by ipsilateral anaesthesia of the brachial plexus (+36%, P<0.01). This was the case also for femoral artery distensibility both following ipsilateral subarachnoid anaesthesia in healthy subjects (+47%, P<0.05) or ipsilateral sympathetic gangliectomy in patients with peripheral artery disease (+26%, P<0.05). In all three instances, the distensibility of the contralateral artery remained unaffected. CONCLUSIONS: These data indicate that the sympathetic nervous system exerts a marked tonic restraint of arterial distensibility. This restraint involves medium-size and large muscular arteries and can also be seen in subjects with peripheral artery disease. This stiffening influence may increase the traumatic effect of intravascular pressure on the vessel wall and favour atherosclerosis.

Adult↗
PubMed1998

Graft-tunnel mismatch in endoscopic anterior cruciate ligament reconstruction. Intraoperative and cadaver measurement of the intra-articular graft length and the length of the patellar tendon.

The results of a study conducted on 50 knees endoscopically reconstructed for an anterior cruciate ligament (ACL) lesion with a free bone-patellar tendon-bone graft and 9 cadaver knees are reported. The mean lengths of the patellar tendon (45.48 +/- 4.71 mm) and intra-articular ACL graft (20.44 +/- 1.98 mm) were measured in the operated knees. The mean length of the tibial bone tunnel (51.62 +/- 2.60 mm) was also measured with a tibial guide at 55 degrees. No statistically significant correlation was found between these three measurements. The length of the patellar tendon was weakly correlated with body height. Measurement of the tibial tunnel on the cadaver knees with increasing degrees of inclination revealed a mean length increase of 0.68 mm per degree (confidence limits: 0.49-0.86). Comparison between the tunnel lengths obtained with the guide and those measured with a Kirschner wire showed a mean difference of 2.3 mm. It is thus desirable to make the tunnel about 53 mm long to ensure excellent fixation of a 28 mm bone block with a 25 mm interference screw. Correct measurement of the anatomical structures involved is in any event an essential requirement for proper execution of the surgical technique.

Adolescent↗
PubMed1998

Bone assessment after total knee arthroplasty by dual-energy X-ray absorptiometry: analysis protocol and reproducibility.

Bone quality is important for the success of joint prostheses implantation, and the assessment of bone density after total knee arthroplasty by means of dual-energy X-ray absorptiometry may be useful for monitoring implant stability. The aim of this study is to suggest a validated analysis protocol for the assessment of bone status after total knee arthroplasty. A dedicated densitometric analysis protocol of five regions of interest was designed, and 10 subjects who had received an uncemented knee prosthesis (8 females and 2 males, aged 55-74 years) underwent three consecutive scans in posteroanterior and lateral projections, with repositioning after each scan to test the suitability and reproducibility of the protocol. The reproducibility of the measurement of bone mineral content and density in the femoral and tibial regions ranged, respectively, from 2.1% to 4.1%, from 0.9% to 2.6% for the posteroanterior scans, and from 2.7% to 5.6% and from 2.3% to 4.7% for the lateral scans, depending on the considered region. Our results confirm that the suggested protocol allows precise assessment of bone mineral content and density, and that dual-energy X-ray absorptiometry is reliable for the evaluation of bone mass around prosthetic implants.

Absorptiometry, Photon↗
PubMed1998

Effects of prolonged immobilization of the limb on radial artery mechanical properties.

Physical training is associated with an increase in arterial distensibility. Whether the effect of training on this variable is evident also for ordinary levels of exercise or no exercise is unknown, however. We have addressed this issue by investigating the effect on radial artery distensibility of prolonged monolateral immobilization of the ipsilateral limb versus the following resumption of normal mobility. We studied 7 normotensive subjects (age, 25.4+/-3.0 years; systolic/diastolic blood pressure, 119+/-9/68+/-6 mm Hg, mean+/-SE) in whom 1 limb had been immobilized for 30 days in plaster because of a fracture of the elbow. At both the day after plaster removal and after 45 days of rehabilitation, radial artery distensibility was evaluated by an echo-tracking device (NIUS-02), which allows arterial diameter to be measured noninvasively and continuously over all pressures from diastole to systole (finger monitoring), with the distensibility values being continuously derived from the Langewouters formula. In both instances, the contralateral arm was used as control. Immediately after removal of the plaster, radial artery distensibility was markedly less in the previously immobilized and fractured limb compared with the contralateral limb (0.4+/-0.1 versus 0.8+/-0.1, 1/mm Hg 10(-3), P<0.05). After rehabilitation, the distensibility of the radial artery was markedly increased in the previously fractured limb (0.65+/-0.1 1/mm Hg 10(-3), P<0.05), whereas no change was seen in the contralateral limb. Thus, complete interruption of physical activity is associated with a marked reduction of arterial distensibility, indicating that even an ordinary level of activity plays a major role in modulation of arterial mechanical properties.

Adolescent↗
PubMed1997

Pre- and postoperative intra-articular analgesia for arthroscopic surgery of the knee and arthroscopy-assisted anterior cruciate ligament reconstruction. A double-blind randomized, prospective study.

We tested the effectiveness of different intra-articular analgesics and of pre-emptive intra-articular analgesia for arthroscopy-assisted anterior cruciate ligament reconstruction (ACLR) and for operative knee arthroscopy. Eighty-two patients underwent operative knee arthroscopy under selective subarachnoid anaesthesia (group A), and 60 patients underwent arthroscopy-assisted ACLR under general anaesthesia (group B). Patients were randomly assigned to intra-articular analgesic treatment as follows. Group A: 1, morphine 2 mg; 2, preoperative morphine 2 mg; 3, morphine 5 mg; 4, preoperative morphine 5 mg; 5, bupivacaine 0.25% 20 ml; 6, bupivacaine 0.25% 20 ml + morphine 2 mg; 7, saline solution 20 ml. Group B: 1, morphine 2 mg; 2, morphine 5 mg; 3, preoperative morphine 5 mg; 4, bupivacaine 0.25% 20 ml; 5, bupivacaine 0.25% 20 ml + morphine 2 mg; 6, saline solution 20 ml. All opioids were diluted in 20 ml of saline solution. After postoperative administration the tourniquet was left in place for 10 min. After preoperative administration the intra-articular surgical procedure was delayed for about 5-10 min. In the postoperative period we recorded: total consumption of ketoprofen given i.v. on demand as rescue analgesic treatment; pain scores before surgery and at 1st, 3rd, 6th, 12th and 24th h; occurrence of local anaesthetic or opioid side-effects. Group A (operative knee arthroscopy): all morphine groups (A1, A2, A3, A4) and the bupivacaine group (A5) did not require ketoprofen postoperatively (P < 0.01 vs both groups A6 and A7). Pain scores did not differ significantly among groups. The percentage of patients reporting higher pain scores than before surgery was larger in control group A7 and in bupivacaine groups A5, A6 (83%, 40%, 60%, respectively) and lower in morphine groups A1, A2, A3, A4 (25%, 16%, 27%, 23%, respectively). Group B (ACLR): total consumption of ketoprofen was lowest in groups B2 and B3 (P < 0.001 vs all other treatments and vs control group). The percentage of patients who did not require any rescue analgesic was 60% in group B3, 50% in group B2, 32% in group B5 and 0% in all other groups. No-side effects occurred in any patient. Intra-articular analgesia is safe and effective for arthroscopic knee surgery. Morphine provides a better pain control both in operative knee arthroscopy patients and in ACLR. A 2 mg dose is adequate for operative knee arthroscopy but not for ACLR, where higher dosages are required (5 mg). Pre-emptive intra-articular morphine provides better analgesia than postoperative administration.

Adult↗
PubMed1995

Long-term results of the Leeds-Keio anterior cruciate ligament reconstruction.

This paper discusses the long-term results of the anterior cruciate ligament (ACL) reconstruction with the Leeds-Keio (LK) prosthetic ligament. For this type of reconstruction we used arthrotomy and an arthroscopy-assisted technique. The fixation was obtained with two bone plugs, and the distal portion was also attached with a staple. A postoperative protocol was used with a progressive range of motion and weight bearing after 50 days. We performed 50 LK operations in professional and amateur athletes aged 17-39 years with an isolated anterior instability. We reviewed at follow-up (5-7 years) 37 patients; 8 were lost, and 5 had a subsequent failure. At the Lysholm score the patients were classified: 19 excellent, 13 good, 3 fair, and 2 poor. At the IKDC grading the patients were classified as follows: 2 class A, 22 B, 8 C, and 5 D. The Lachmann test was 1+ in 15 patients, 2+ in 7, 3+ in 2, and negative in 13; pivot shift was 1+ in 9, 2+ in 7, 3+ in 2, and negative in 25. Results of the KT 1000 test at 30 lb side to side was < 3 mm in 23 patients, 3-5 mm in 6, 6-10 mm in 6, and > 10 mm in 2. In view of the results observed and the progressive deterioration over the years, this procedure should no longer be performed as an ACL substitute.

Adolescent↗
PubMed1995

Magnetic resonance imaging versus arthroscopy for the investigation of the osteochondral humeral defect in anterior shoulder instability. A double-blind prospective study.

A double-blind prospective study was done with 15 patients with anterior shoulder instability to determine the diagnostic efficacy of magnetic resonance (MR) imaging versus arthroscopy in the evaluation of chondral or osteochondral lesions of the humeral head. MR produced 6 true positives, 5 true negatives and 4 false negatives, and its accuracy and sensitivity were 60% and 87%, respectively, whereas arthroscopy gave 8 true positives, 5 true negatives and 2 false negatives, with a sensitivity of 80% and an accuracy of 87%. All lesions diagnosed with either method were regarded as positive by definition, with the result that the specificity was always 100%. The differences in diagnosis sprang from the false negatives. The 40% discrepancy between the two methods was probably due to our distinction in MR between intra- and extra-articular osteochondral lesions. In the first group (the 4 MR false negatives), there were three instances of first-degree intra-articular lesion and one diagnostic error (third-degree lesion). In the second (the 2 arthroscopy false negatives), the lesions were of the extra-articular type. It is thus advisable to employ both of these methods to ensure the correct diagnosis of a Hill-Sachs lesion, and hence the correct choice of treatment.

Adolescent↗
PubMed1995

[A statistical model for evaluation of air microbes in pharmaceutical production areas. Group for the study of microbiology of the AFI].

In this study it has been proposed a statistic model to evaluate results concerning microbial count of the air obtained in areas of pharmaceutical production. Nowadays both official methods and agreement about limits of microbial count to use in production areas in which non sterile forms has been processed, are absent. The proposed statistic model foresees a processing data that admits a building of "Flow Charts". Two flow chart has been built: the "Mean Flow Chart" and the "Range Flow Chart". The "Mean Flow Chart" shows the data distribution around the mean value, the "Range Flow Chart" points out the data variation. In this way it has been established the process natural tolerance and the relative limits assumed by the variable in exam. If values of microbial count result of limit, the causes have to be investigated and it's necessary to take adequate countermeasures.

Air Microbiology↗
PubMed1994

Comparison of "catheter" and conventional arthroscopy in the diagnosis of knee derangements.

The diagnostic efficiency of the Optical Catheter System (OCS), which uses a 1.7-mm arthroscope, was compared with that of conventional arthroscopy in 50 patients with various knee derangements in standard arthroscopic conditions. Correct diagnoses were obtained with the OCS in 98% of anterior cruciate ligament derangements--92%-98% of those involving the medial and lateral meniscus, respectively--and 96% of cartilage disorders. No false-positives were noted for anterior cruciate ligament and meniscus injuries. False-negatives were caused by abundant intraarticular bleeding (no tourniquet was applied) and peripheral meniscus tears and false-positives by synovial superposition resulting in a mistaken diagnosis of patellar chondromalacia. The OCS proved a good diagnostic tool. Its employment, especially in an outpatient setting, should be restricted to a small number of patients and entrusted to expert arthroscopists.

Adolescent↗
PubMed1994

Anterior cruciate ligament mechanoreceptors. Histologic studies on lesions and reconstruction.

The fate of mechanoreceptors was studied in torn and reconstructed anterior cruciate ligaments in animals and in humans. In untreated anterior cruciate ligament lesions in humans, morphologically normal mechanoreceptors remained in the ligament for 3 months after the injury. After that time, their number gradually decreased. By the 9th postinjury month, only a few free nerve endings were present. Even free nerve endings were totally absent in the biopsy specimens from 1-year-old lesions. In experimental animals, anterior cruciate ligament reconstruction with autologous patellar tendon resulted in the presence of mechanoreceptors in the reconstructed anterior cruciate ligament. When an artificial ligament was used, no mechanoreceptors were found. Morphologically normal mechanoreceptors were present in 2 patients with a lax biologic anterior cruciate ligament reconstruction 9 and 10 years after the operation.

Animals↗
PubMed1993

The bone-ligament junction: a comparison between biological and artificial ACL reconstruction.

The physiological bone-ligament junction is composed of four zones: ligament, fibrocartilage, calcified fibrocartilage and bone. It plays a very important part in the distribution of mechanical loads applied to ligaments so as to diminish stress concentration or shearing at the interface. This paper examines types of bone and neoligament insertion after anterior cruciate ligament (ACL) reconstruction with a Dacron prothesis, the Leeds-Keio scaffold ligament (LK), patellar tendon with LAD augmentation (PT+LAD) and bone patellar tendon bone alone (PT). The anterior cruciate reconstructions were implanted in 16 sheep via double-isometric bone tunnels without postoperative knee immobilization. Histological examination of the new insertions (using haematoxylin-eosin, Giemsa, Masson, and Mallory stains) was performed following animal sacrifice after 2, 3, 6 and 9 months. A layer of fibrocartilage between the bone and the ligament was observed with PT, followed by a nearly normal insertion after 6 months. With PT, followed by PT+LAD, the augmentation was surrounded by fibrous tissue (also noted inside the LAD). The PT insertion was virtually physiological after 3-6 months. With the LK scaffold, fibrous tissue was noted in and around the scaffold, even after 6 and 9 months. With the Dacron prosthesis, fibrous tissue around the ligament was unaccompanied by ingrowth into the prosthesis. Nerve endings (pacinian corpuscles) were only present in the PT. These findings show that even after 9 months artificial ligaments are separated from bone by fibrous tissue and devoid of the histological and biomechanical features of a physiological junction.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Arthroscopic lateral retinacular release of the alar ligament. Indications and long-term results.

The indications for and results of arthroscopic release of the lateral alar ligament are evaluated. This technique was used exclusively in cases of anterior patellar pain due to lateral hypertension resulting from disalignment of the extensor apparatus. It was used on 21 knees with a follow-up of 15-36 months. Excellent or good results were obtained in 85% of the cases, according to both subjective and objective evaluation.

Adolescent↗
PubMedDate not supplied

The OCTOPUS system for acetabular reconstruction.

In revision surgery of the hip, reconstruction of the acetabulum often constitutes the most complex procedure. There is frequently a considerable loss of bone substance, and correct repositioning of the rotation center of the femoral head is required. Based on surgical experience supported by clinical results the authors affirm that both of these objectives may be achieved when the OCTOPUS socket system is used. This implant, with anchoring to the iliac bone and the use of bone transplants, allows for the reconstruction of the original anatomy of the cotyle.

Acetabulum↗