The biomolecular interactions between endothelium and bone cells: an overview.

Bone turnover is a complex set of different molecules pathways and it is strictly connected with bone vasculature. It includes every bone process concerning bone modelling and remodelling such us skeletal growth and healing process. A fundamental component of this bone architecture is played by the endothelium, that acts in a paracrine fashion on other bone stromal cells via humoral factors, growth factors and chemokines/cytokines. The alteration of those biochemical interactions between endothelium, vasculature and bone tissue may cause various pathological manifestations. Understanding the bases of the interaction between those different pathways could provide novel therapeutic strate¬gies for bone disease. The Authors present an updated overview of the most common communication biomolecules between bone cells and endothelium and their interactions both in healthy and pathological conditions. Furthermore, focusing on gene and related therapies, possible future therapeutic strategies for bone vasculature/metabolic diseases are presented.

Total knee arthroplasty after complex tibial plateau fractures.

Total knee arthroplasty following complex fractures of the tibial plateau is considered a challenge for orthopaedic surgeons and clinical outcomes may vary. A total of 29 total knee replacements were performed after a tibial plateau fracture: 25 patients (16 women, 9 men; average age: 57 years; mean follow-up: 92 months) were available. We had two significative complications: one partial avulsion of the patellar tendon, conservatively treated by bracing, and one case of deep venous thromboembolism, managed with low molecular weight heparin. In two cases (8%) there was a failure of the implant; nine cases were excellent, nine good, four fair and one poor. A percentage of patients with previous complex proximal tibia fractures had an increased rate of postoperative complications due to anatomical deformity, functional deficiency and post-traumatic arthritis and required solutions similar to revision surgery. Total knee arthroplasty is a suitable solution for the treatment of these challenging cases: compared to primary knee replacement, final KSS score is generally lower, but improvement is similar due to poorer pre-operative scores.

Acetabular revisions using a cementless oblong cup: five to ten year results.

The purpose of this paper was to evaluate the results of acetabular revisions with the use of an oblong revision cup that is designed with its longitudinal diameter elongated relative to its transverse diameter. Between 1996 and 2001, 62 hips in 60 patients underwent an acetabular revision with the insertion of a LOR acetabular component. Seven hips were lost to follow-up or the patients died; the remaining 55 hips (53 patients) remained in follow-up for an average of 7.2 years (range: 5.0-10.1 years). One socket was revised for aseptic loosening, and another was operated on for a late polyethylene liner dissociation. The average Harris hip score (HHS) improved from 34 to 79. Results were rated as excellent in 16 hips, good in 28, fair in six and poor in three. Radiographic analysis demonstrated an improvement in the average vertical displacement of the hip centre: 49 hips had a well-fixed, bone-ingrown cup and four had a stable fibrous union. For large superolateral acetabular bone deficiencies, this implant facilitated a complex reconstruction without the need for bulk structural acetabular bone grafts, provided good clinical results and showed satisfactory stability at the midterm follow-up.

A modular total knee arthroplasty in haemophilic arthropathy.

The results of 24 modular Genesis II (Smith & Nephew, Memphis, TN, USA) total knee arthroplasties, performed in 20 patients with haemophilia were prospectively reviewed. The hypothesis that the use of a new-generation implant and advanced, more aggressive hematological care, will result in a decrease rate of complications and better functional results for the haemophilic patients with TKA was tested. The mean age at the time of surgery was 36 years (25 to 44). All the patients were reviewed clinically and radiologically with an average follow-up of 4.4 years (2 to 7 years). At the final follow-up the knee score improved from an average of 23 points (11 to 45) to 86 points (62 to 100; p<0.001). The mean knee flexion contracture improved from 22 degrees (0 degrees to 45 degrees ) to 3 degrees (0 degrees to 10 degrees ; p<0.0001). The mean total flexion arc improved from 69 degrees (5 degrees to 130 degrees ) to 92 degrees (80 degrees to 145 degrees p<0.001). The results of our study confirm that the introduction of modular design may improve the functional results of TKA in haemophilic arthropathy which results in a better range of motion and lower flexion contracture.

Planning for minimally invasive unicompartmental knee arthroplasty.

Unicompartmental knee arthroplasty (UKA) is considered the treatment of choice in patients with single compartment arthritis of the knee at early stages or with osteonecrosis limited to one compartment. However, results in the literature are still controversial and it is a technically difficult procedure. The main goal of UKA is to restore the articular space of the afflicted compartment, without influencing the limb alignment. Selection of patients and pre-operative planning are crucial. The necessity to improve functional results and to reduce immobilization of the patients has led to the development of minimally invasive surgery. Applied to UKA, this approach reduces blood loss and surgical time, causes fewer symptomatic postoperative complications, and permits earlier recovery compared to the traditional incision. The shorter incision makes careful pre-operative planning essential. We briefly review the indications for UKA, the pre-operative clinical and radiological assessment, and the surgical procedure.

Regulation of inherently autoreactive VH4-34 B cells in the maintenance of human B cell tolerance.

The study of human B cell tolerance has been hampered by difficulties in identifying a sizable population of autoreactive B lymphocytes whose fate could be readily determined. Hypothesizing that B cells expressing intrinsically autoreactive antibodies encoded by the VH4-34 heavy chain gene (VH4-34 cells) represent such a population, we tracked VH4-34 cells in healthy individuals. Here, we show that naive VH4-34 cells are positively selected and mostly restricted to the follicular mantle zone. Subsequently, these cells are largely excluded from the germinal centers and underrepresented in the memory compartment. In healthy donors but not in patients with systemic lupus erythematosus (SLE), these cells are prevented from differentiating into antibody-producing plasma cells. This blockade can be overcome ex vivo using cultures of naive and memory VH4-34 cells in the presence of CD70, IL-2, and IL-10. VH4-34 cells may therefore represent an experimentally useful surrogate for autoantibody transgenes and should prove valuable in studying human B cell tolerance in a physiological, polyclonal environment. Our initial results suggest that both positive and negative selection processes participate in the maintenance of tolerance in autoreactive human B cells at multiple checkpoints throughout B cell differentiation and that at least some censoring mechanisms are faulty in SLE.

Antibiotic prophylaxis in elective neurosurgery. Epidemiological study.

The authors present an epidemiological study of patients who have undergone elective neurosurgery and who have been treated with different types of antibiotics throughout a ten year time span. From the statistic analysis of the different parameters taken into consideration (administering modalities of the short-term and long-term antibiotic, type of sepsis encountered, isolated microorganisms) the authors show, as a result, that the long-term antibiotic prophylaxis is a clearly improper method; the short-term prophylaxis is a correct method the effect of which is, however, still controversial as it does not modify a natural low percentage of infections in elective neurosurgery. The role given to the antibiotic seems much less important compared with the adoption of correct antiseptic measures and of proper nursing.

Vascular injury related to lumbar disk surgery.

The authors report a case of left common iliac artery injury, as a complication of diskectomy, in a 57 year-old male patient, with herniated disk at L4-L5. A review shows that L4-L5 disk space is the most common site for this rare complication of lumbar disk surgery.

A rare case of Toxocara canis arachnoidea.

The Authors present a case of Toxocara canis arachnoidea located in the cervical zone. The rarity of the case and the extreme rarity of the position are emphasized. In fact in medical literature there exists a description of only one similar case which was also observed by one of the authors.

[Lymphocytic infiltration in cerebral gliomas]. / L'infiltrazione linfocitaria nei gliomi cerebrali.

The authors analyse the incidence, extent and prognostic significance of lymphocytic infiltration in 80 cases of operated cerebral gliomas (61 high- and 19 low-grade gliomas). The results obtained are discussed in relation to the data previously reported by the literature.

Prognostic significance of lymphoid infiltration in cerebral malignant gliomas.

Data concerning a study on lymphoid infiltration in 61 cerebral malignant gliomas are reported. Lymphoid cellular infiltrates were found in 28 cases (45.9%): 8 (13.1%) with marked and 20 (32.8%) with slight infiltration; the remaining 33 cases (54.1%) did not exhibit lymphoid infiltration. The mean survival time (+/- standard deviation) of patients harboring gliomas with marked lymphoid infiltration was 20.5 (+/-19.9) months, and that of patients with slight lymphoid infiltration in their glioma was 10.3 (+/- 7.5) months; those patients having gliomas without lymphoid cellular infiltrates showed a mean survival time (+/- standard deviation) of 7.2 (+/-6.1) months.

Intracerebral haemorrhage: criteria for prognosis on the grounds of clinical and CT data.

The Authors report analyses on 83 cases of brain haemorrhage which were conducted over a period of 6 years. On the basis of previous studies made by the same authors, a selection was made from patients whose survival index rating did not exceed 8.1. These patients were treated only with medical and reviving therapies. In this work we attempt to formulate some considerations regarding the prognosis of brain haemorrhage on the basis of clinical and tomodensitometric data.

[The role of inflammatory infiltrate as a prognostic criterion in cerebral metastases. Preliminary results]. / Ruolo dell'infiltrato infiammatorio quale criterio prognostico nelle metastasi cerebrali. Risultati preliminari.

Data concerning a preliminary study on the prognostic significance of inflammatory infiltration in cerebral metastases are reported. Seventeen cases of operated cerebral metastases have been studied to investigate their histotype and grade of necrosis, stromal reaction, and inflammatory infiltration. Finally, the results obtained are discussed in relation to the postoperative survival rate of the patients.

[The role of the blood viscosity and hematocrit value in acute stroke. Experimental considerations]. / Il ruolo della viscosità ematica e del valore ematocrito nello stroke acuto. Considerazioni sperimentali.

The link between blood viscosity, Ht and the onset of stroke is highlighted and reports in the literature are examined. On this basic, the paper proposes an experimental model of cerebral ischaemia in the rabbit as providing a better insight into this aspect which may be highly significant, particularly in the prevention of strokes.

The operation of arthrodesis for malformations of the occipito-atloid joint, according to Gilles Bertrand.

Malformations of the occipito-vertebral hinge destabilize the bones and injure the neural structures of the bulbo-spinal junction and of the cervico-spinal cord. The Authors have found the Gilles Bertrand intra-articular C/1-C/2 bilateral arthrodesis to be an extremely efficient surgical procedure for stabilizing the occipito-atlo-axial region, producing a relative lowering of the odontoid and relieving pressure in the occipito-atloid region. Excellent post-operative results derive from the relatively easy and non-destabilizing operative procedure. No deaths have been recorded in connection with this operation. This contrasts with the traditional occipito-atloid pressure-relieving procedure (either with or without opening of the dura mater), a procedure which, in addition to not stabilizing the upper cervical spine, sometimes results in the patient's death.

Traumatic aneurysms of the carotid artery. Case report.

The Authors report a rare case of traumatic aneurysm of the internal carotid artery observed in a 19-year-old man after a car accident. The aneurysm was recognized by cerebral angiography performed immediately after trauma and clipped to avoid delayed rupture. The literature on traumatic aneurysms is reviewed.