Biomedical subjects

C A Veronesi

Publications and source records attributed to C A Veronesi.

5 recordsLinked to original sources

PubMed2003

Ion release in stable hip arthroplasties using metal-on-metal articulating surfaces: a comparison between short- and medium-term results.

The use of metallic heads articulating with metallic cups could solve the problem of polyethylene (PE) wear in total hip replacement (THR) with metal-on-PE bearings. A conspicuous release of metal ions from new models of metal-on-metal bearings has been found in the short-term, but it is yet unclear whether the medium-term corrosion rate is high or, on the contrary, it becomes negligible, because of the continuous surface finishing. Our purpose was to compare the serum ion values (nanograms per milliliter) in 15 patients with metal-on-metal stable prosthesis (Group A), in the short-term (subgroup A(1); mean follow-up: 24 mo) and medium-term (subgroup A(2); mean follow-up: 52 mo), in order to determine whether the ion release decreased with time of implant. Chromium (Cr), cobalt (Co), molybdenum (Mo) and aluminum (Al) were analyzed. Twenty-two presurgical patients were used for comparison (Group B). The reference range was obtained from a population of 27 healthy subjects (Group C). Co and Cr levels in the medium-term (subgroup A(2)) were not decreased in comparison with the short-term values (subgroup A(1)) and were significantly higher (p < 0.001) than presurgical and reference values. Otherwise, Mo and Al concentrations were not significantly increased in comparison with reference values. In conclusion, despite the apparent advantage of metal-on-metal coupling, especially in younger patient populations, there is a major concern about the extent and duration of the relevant "internal" exposure to Cr and Co ions. This exposure should be carefully monitored, in order to clarify the biologic effects of ion dissemination and, consequently, to identify risks concerning long-term toxicity of metals.

Adult↗

PubMed2002

Ion release in patients with metal-on-metal hip bearings in total joint replacement: a comparison with metal-on-polyethylene bearings.

Polyethylene (PE) wear has been shown to be a problem in long-term joint replacement using metal-on-PE bearing. The use of metallic heads articulating with metallic cups could solve this problem: success will be enhanced if wear and corrosion of the articulating surfaces are maintained at a low level. New models with metal-on-metal bearing have been proposed, to be used mainly for young subjects: such coupling seems to have a reduced release, but it is unclear yet if the medium-term corrosion rate is really negligible or, on the contrary, it is significantly higher than in the metal-on-PE bearing. Aim of our study was the comparison of ion release in the serum of two groups of patients who had the same type of stable cementless prosthesis, but different bearing: twenty-six patients with metal-on-metal (Group A) and fifteen patients with metal-on-PE bearing (Group B) were examined. The follow-up was 14-38 months for group A and 18-34 months for group B. The serum concentration of chromium (Cr), cobalt (Co) and molybdenum (Mo) was measured. Twenty-two patients before surgery were used for comparison (Group C). The reference values were obtained from a population of twenty-two healthy subjects (Group D). Our findings indicate that metal-on-metal bearings produce a significantly higher systemic release of cobalt and chromium (ng/ml) when compared with levels found in metal-on-PE, pre-surgery and reference groups. Such a high release should induce to improve the bearing materials or, at least, to study the biologic fate of metal ions and consequently their long-term effects. In such a way a risk-to-benefit ratio for the patient could be established.

Adult↗

PubMed2002

Phalangeal ultrasonography in forearm fracture discrimination.

Over the last decade, the use of ultrasounds has been developed into an effective tool for investigating bone tissue and predicting the risk of fracture in osteoporosis. Studies have focused on hip and vertebral fractures while no information is available on the use of phalangeal ultrasonography to identify patients with forearm fractures. Thus, the current authors decided to compare 50 postmenopausal women with low energy forearm fractures (Fractured Group) with a control age-matched group of 94 women (Control Group). Measurements were taken at the distal metaphysis of the proximal phalanxes of the hand of the non-fractured arm using the DBM Sonic Bone Profiler. The reproducibility of the method was assessed by amplitude-dependent speed of sound (AD-SoS) CV% = 0.64 and by Ultrasound Bone Profiler Index (UBPI) CV% = 2.38. In the Control Group, the AD-SoS and UBPI mean values and standard deviations were significantly higher compared to the group with fractures (P < 0.0005). The receiver operating characteristic (ROC) curves were calculated and the areas under the curve (AUC) were 0.78 +/- 0.04 for AD-SoS and 0.77 +/- 0.05 for UBPI, respectively. Logistic regression analysis adjusted to age revealed that both AD-SoS (78.2%, ORAD-SoS = 12.03, P < 0.0005) and UBPI (76.0%, ORAD-SoS = 7.39, P < 0.0005) parameters discriminated correctly between fractured and non-fractured control women whereas the association of both parameters could not allow better discrimination. The present results showed that ultrasound investigation at the phalanxes is reproducible and efficiently discriminates between subjects with forearm fractures and those in the control subjects.

Aged↗

PubMedDate not supplied

Experimental study on rotator cuff repair.

It was the purpose of the experimental study to use laboratory experience to verify the effectiveness of different methods used to repair the rotator cuff. The sheep was used as an animal model because its infraspinous tendon is the most similar to that in the human. Three static trials were conducted using Instron machines, comparing the repair systems used most by the same authors in their clinical work, the hold of the suturing wires with two different threading procedures in the bone tunnels and two types of knotting, and the breakage loading of the suturing wires in the two different miniplate systems. The authors conclude that tendinous anchoring must be entrusted to reinforced suturing systems (modified SCOI and Mason Allen), the threading of wires in pairs in a single bone tunnel makes surgery easier and shortens the amount of time required, with threading of wires similar to or better than threading with a single wire. There are no differences in breakage loading of the wire at the level of the holes in the two miniplates considered in this study.

Animals↗

PubMedDate not supplied

The surgical treatment of Rockwood grade III acromioclavicular dislocations.

The conservative or surgical treatment of Rockwood grade III acromioclavicular dislocations continues to be a controversial subject. Thus, the authors report their experience with 52 cases; long-term follow-up was obtained for 40 of these, paying close attention to the preoperative clinical and radiographic evaluation and to the results obtained in order to ascertain whether or not surgical repair is required. The results of surgical treatment, however satisfactory (90% excellent or very good), are nearly the same as those obtained when non surgical treatment is used as reported in the international literature. The authors conclude that the use of surgical treatment must be limited to carefully selected cases, should prolonged conservative treatment fail. Of the three surgical techniques used, temporary stabilization of the acromioclavicular joint using AO wires associated with restoration of the coracoclavicular connections has proven to be more effective than Dall-Miles metal wiring and tangential resection, with a lower incidence of complication.

Acromioclavicular Joint↗