Introduction: Osteoporosis is a disease characterized by a low bone mass and the development of nontraumatic fractures. Approximately 700,000 elderly women in the US are newly diagnosed with osteoporotic vertebral fractures every year. Noninvasive measurements of bone mineral density (BMD) are central to the diagnosis and management of osteoporosis. However, BMD alone is not completely satisfactory in vertebral fracture risk assessment. The aim of this study was to identify clinical and laboratoristic factors associated with an increased risk of vertebral fractures in osteoporotic Caucasian women and to define a new clinically relevant scale of risk.

Methods: 475 patients consecutively admitted at our ambulatory for the treatment of vertebral osteoporosis were included in the study. All patients were affected by post-menopausal osteoporosis according to the WHO classification criteria. Exclusion criteria were major infectious diseases, tumors and major diseases of sense organs. We attempted to determine whether parameters such as age, body mass index, smoking and alcohol habitudes, femoral and lumbar T-scores, femoral and lumbar Z-scores, femoral and lumbar BMD, total and bone alkaline phosphatase and L3 and T7 vertebral volumes were associated with the risk of vertebral fractures.

Results: 173 patients of the entire population presented at least one vertebral fracture for a total of 488 fractures (238 thoracic and 250 lumbar collapses). When considered alone, age (> 65 years-p=0,0001), lumbar T-score (≤-3,5-p=0,0001), lumbar Z-score (≤-2,5-p=0,0050), lumbar BMD (≤0,800-p=0,0017), femoral T-score (≤-3,5-p=0,0090), femoral Z-score (≤-2,5-p=0,0127), L3 volume (≤-2,0SD–p=0,0023) and T7 volume (≤-2,0SD–p=0,0075) were significantly associated with an increased risk of vertebral fractures. Considering only the patients with two fractures or more, the same parameters with the exception of the femoral T-score resulted strongly associated with the risk of new vertebral fractures. Moreover, there was a significantly increased risk of vertebral fractures when two or more of these parameters were present together (p = 0.02). On the base of the obtained data we have then defined a new scale of risk (from grade I-low risk to grade IV-very high risk-p=0.0123) confirmed in a prospective study conducted on 71 osteoporotic patients followed for 30 months.

Conclusion: We propose a new clinical scale to easily identify the osteoporotic patient at risk of new vertebral fractures.

The experimental determination of residual stress fields on the surface of retrieved femoral heads represents a fundamental step in understanding their wear degradation behavior and the tribological mechanisms, which are operative on the femoral joint during its working life time. In this work, the surface of retrieved alumina and zirconia (Al2O3 and ZrO2) femoral heads were investigated by piezo-spectroscopic tecniques based both on photoluminescence and Raman effects. The high spatial resolution of the laser, impinging on the investigated surface (typically about 1 micron of lateral resolution), enabled us estimating patterns and magnitude of residual stress in extremely narrow zones, comparable with the grain size of the material.

Four retrieved ceramic femoral heads were analyzed. Two balls were made of alumina with a typical grain size of from 4 to 10 microns. Both alumina balls were retrieved after only few years from implantation, due to septic and aspetic loosening. The remaining two femoral heads were made of zirconia with a typical grain size of 1 micron. These latter balls were retrieved after 2 and 13 years, respectively (both for loosening problems). With a systematic collection of a large number of data on a microscopic level it was possible to assess the retrieved femoral heads in to to, thus extending the microscopic analysis to the entire joint.

In allumina balls retrieved after short time implantation, a macroscopic stress field was found, which arose from manufacturing, loading history, and the displacements acting on the femoral head during its lifetime. This stress field was completely overcome by a microscopic residual stress field due to local contacts (e.g., local shocks owing to microseparation, impinging and wear contacts). On the other hand, in zirconia femural heads, the major amount of surface deterioration after long-term exposure arose from tetragonal-to-monoclinic transformation in biological environment. These data allowed us to draw interesting considerations about the role of the material microstructure and the peculiar kinematic mechanisms involved with the use of femoral heads made of different materials.

Spectroscopic techniques, which are complementary to in vitro testing procedures and stress analyses based on finite-element methods, can be very useful for improving the design of the femoral head and for optimizing the microstructural characteristics of the ceramic materials employed. Based on this and previous fluorescence and Raman spectroscopic studies, we also propose that a systematic screening of the ceramic implants before implantation can strongly reduce the probability of failure of the implant.

Aims: Hydroxyapatite (HA) is widely known in orthopaedic surgery and is proved to be safe and effective in bone substitution. Actually synthetic HA is a merely reproduction of the chemical constitutes of the natural HA (Ca, P). New technologies demonstrate that it is possible to assembly new materials starting from the primary microscopic unit (nano molecules) with a process called “bottom to the top”, realizing macromolecules biologically active and smart. Even bone is nano structured in HA crystalline units (20–40 nm) regularly oriented upon collagen fibres (300 nm).

Methods: This study concern a new nano structured HA realized by an auto assembled process “biologically inspired”, like in human bone formation, of nano HA crystals and collagen as to realize a new material very similar to natural bone. Samples of the nano-HA were tested in living bone in vivo (rabbits) and compared with a synthetic Mg-HA (Ha added with Magnesium). Macroscopic, radiographic, light microscopic and SEM analysis were performed periodically. New osteogenesis, bone ingrowth and ongrowth, bone apposition rate were evaluated up to 12 weeks. :The preliminary results of this study showed for both the biomaterials optimal bone apposition and biocompatibility. In the first month an earlier osseointegration was observed in traditional Mg-HA samples. The histological examination revealed a primary direct bone apposition from the surrounding living bone. The Nano-HA samples showed a slower secondary bone apposition, may be because of the initial larger gap and consequent lesser direct contact between the material and the guest bone. No adverse effect or reactive phenomenon were observed.

Conclusions: This study demonstrates the reliability of this new nano structured HA that demonstrates to be biologically active and useful in bone substitution. Further studies will reveal new promising improvements in bone substitution with interesting multidisciplinary innovations.

The Authors analysed two cases of catastrophic failures of Total Hip Prostheses due to the disruption of the PE inlay and the Ti-alloy metal back of the acetabular components. In the cases reported the PE inlay (4 mm in thickness) was coupled with a 32 mm in diameter Alumina ball heads. At time of revision the alumina ball heads showed many black marks due to the contacts with the Ti-alloy metal back. The sockets showed severe damages, concentrated in the superolateral zone. The PE inlays were disrupted. Almost a third of the metal back is missing. A large metallosis was also visible in the membrane at the interface between implant and bone. Histologic sections showed a large amount of metallic debris in a pseudovillous membrane. At higher magnification oligonuclear cells in a rich in vessels stroma were in contact with metal particles. PE debris with the characteristic birifrangent aspect to the polarised light microscope was contained into polynuclear giant cells. SEM showed that the size of 25% of particles was less than 1 μm, while the size of 53% of wear debris is in the range from 1 to 5 mm. EDAX confirmed that these particles consisted of Ti alloy. The Authors analysed the possible roles of different factors in the etiology of this cup failures and concluded that in both the cases analysed the initiator of the failure was the size selection of the prosthesis, and in particular the PE thickness, followed by the positioning of the acetabular component. The deformation of the PE inlay leads to rupture of the inlay itself, followed by the direct contact between the Alumina ball head and the titanium alloy cup, causing the disruption of the Ti-alloy metal back, with massive release of wear debris in the surrounding tissues.

Aims: Primary non-Hodgkin lymphoma of bone account for 5% of extra nodal lymphomas. The Authors report their experience referring to the results obtained with a multidisciplinary approach.

Materials: 18 cases of lymphoma of bone were included. Medium age was 63 yrs. All cases have been classified according to the REAL classification system. Patients have been staged with: total body CT scan, bone marrow aspirate, bone marrow biopsy, LDH serum level, skeletal survey and MRI of the skeletal segments involved. We treated 10 cases with solitary localization and 8 with multiple ones. Three patients presented with a pathologic fracture at diagnosis.

Chemotherapy protocols were:

MACOP-B < 60 yrs.

VNCOP-B > 60 yrs.

Seven patients received the PROMACE-CYTABOM protocol.

13 patients received EBRT (40 Gy). Ten patients received a surgical treatment: internal fixation in 7 cases and of spine stabilization in 3 cases

Results: At a medium follow-up of 40 months overall survival was 34,6 months and 14,5 months respectively for solitary or multiple localizations. Surgical treatment has been useful in improving performance status and in some cases to obtain a better control of the disease.

Discussion: In our experience bone lymphomas have always a high grade histology. Chemotherapy constitutes the treatment of choice. Surgical treatment have to be considered as a support treatment. Prognosis is worse in multiple localizations

Aim: The differential diagnosis between chondroma and grade I chondrosarcoma still represents a challenge. There are always cases in which a perfect diagnosis can’t be done for sure. This cases are defined in literature with different synonyms such as: borderline chondrosarcoma, grade 0 chondrosarcoma, atypical enchondroma or in situ chondrosarcoma. Enchondroma are benign lesions that do not require a surgical treatment. Low grade chondrosarcoma is a malignant tumour that can recur and also if in a low percentage of cases can metastasize. Methods: The Authors reviewed 22 cases of chondrosarcoma of the limbs for clinical, radiographycal and histological features. Results: Pain was present in 80% of cases of low grade chondrosarcoma, while was absent in enchondroma. Radiographic analysis was not significative. Bone scan was often positive in low grade chondrosarcoma as in enchondroma. Histology demonstrated a permeative pattern in chondrosarcoma with infiltration of the bone trabeculae. Conclusions: Only the complete evaluation of the patient resulted in a correct diagnosis. Follow-up of patients confirmed our findings