Introduction

The number of total hip arthroplasties in young patients is continuosly increasing. Nowdays, the study of the materials wear, with the goal of improving the survivorship of implants, represents a fundamental subject in this kind of surgery. The role of ceramic materials in the valutation of types of wear is particularly known.

Objective: To examine the effectiveness of a specific physiotherapy program before hip arthroplasty in patients with hip osteoarthritis.

Design: Multidimentional prospective randomised controlled study

Subjects: 25 patients meet the inclusion criteria and were randomised in a study and a control group

Intervention: All the patient underwent THA performed by the same surgeon and implanted with the same prosthesis. Study group performed educational and physiotherapy program one month before surgery. Study and control group performed inpatient rehabilitation program only post surgery.

Main outcome measures: patients were evaluated, 1 month before surgery(T0), the day before surgery (T1), 15 days (T2), at 4 weeks (T3) and at 3 months (T4) post surgery using measure of hip muscle strength, hip range of motion, Barthel Index, Short Form-36, WOMAC, Harris Hip Score (HHS), Visual Analogue Scale (VAS).

Results: The study group present significant improvement of hip extrarotation at each evaluation, significant high values of gluteus medius strength (p level 0,004) at T1, significant hip abduction (p level 0,02) at T3, significant lower score in VAS at T1 (p level −2,10), T3 (p level −2,10) and at T4 (p level 0,02), significant improvement in Womac scores (p level −2,32) at T4. In study group, SF 36 Physical composite score was significant high at T1(p level 0,048), Mental composite score at T2 (p level 0,006) and T3 (p level 0,02).

Conclusion: our pre surgery programme improves values of clinical status and social function, besides pain reduced before surgery until three months after surgery.

Aims. Gene therapy research in the field of orthopaedics and traumatology have evolved during the last decade, leading to possible applications for the treatment of pathological conditions, such as bone fractures and cartilage defects. In particular, several gene transfer techniques have been employed so far for inducing bone formation in animal models of bone defects. Cell-based approaches, using in vitro and ex vivo genetically modified cells to be implanted in the animal, produced promising results as they enable the production of physiologic doses of an osteoinductive gene product into selected anatomical sites. In this study we used autologous skin fibroblasts, which are very simple to harvest and propagate in culture, transduced ex vivo with the new osteo-genic factor Lim Mineralization Factor-3 (Ad-LMP-3). These engineered cells produced successful bone healing when implanted by the use of a scaffold in rats, validating the in vivo osteoinductive properties of hLMP-3.

Methods. Primary dermal fibroblasts cultures were established using a 1cm² biopsy of shaved skin obtained from the abdomen of each rat after anesthesia. Semi-confluent primary fibroblasts were infected with either AdBMP-2 or AdhLMP-3 or both, using a overall multiplicity of infection (MOI) of 100 viral particles per cell. Cells transduced with Ad-eGFP at the same MOI were used as a viral infection control, while untreated cells served as a negative control. The transduced cells were harvested 24 hours after viral infection, resuspended in sterile PBS, let adsorbed on a Hydroxyapatite/Collagen scaffold and then implanted in a bone defect surgically performed in the mandible of immunocompetent rats. The animals were divided in 4 groups: 9 rats were treated with cells infected with AdLMP-3, 9 rats with cells infected with AdBMP-2 (positive controls), 9 rats with cells transduced with Ad-eGFP and 9 rats with untreated cells (controls). 3 Rats from each group were sacrified at 1, 2 and 3 months after the treatment and studied by x-rays, Micro-CT and histology (Von kossa and Alizarin staining).

Results. All the animals treated with LMP-3 showed healing of the bone defect after 3 months, as confirmed his-tologically and radiographically. On the contrary none of the controls showed bone formation at latest time point.

Conclusions. Recently, Lim Mineralization Proteins (LMP), coded by three different splice variants (LMP-1, LMP-2, LMP-3) of the same gene, have been identified as regulators of the osteoblast differentiation program. We have previously demonstrated that human LMP-3 (hLMP-3) contributes actively to bone formation, acting at least in part, through the BMP-2 signaling pathway, being capable of inducing differentiation of cells of mes-enchymal derivation towards the osteoblastic lineage, through the up-regulation of bone-specific genes, along with ectopic bone formation in vivo and mineralization in vitro. In this study we have analyzed the efficacy of an ex-vivo approach using autologous dermal fibroblasts infected with AdLMP-3. Engineered cells produced bone healing when implanted by the use of a scaffold in a rodent model, validating the in vivo osteoinductive properties of hLMP-3.

Pain is the main symptom of acetabular osteolysis and is frequently associated with pathologic fractures. Surgical procedures requiring an aggressive approach, and as a consequence high morbidity, are rarely indicated. The minimally invasive approach may be effective in treating tumours and is capable of reducing the mechanical pain. PMMA has been widely used in neoplastic and spinal surgery as a bone filler because of its mechanical and biologic behaviours. Recently percutaneous injection of PMMA was proposed for the treatment of neoplastic acetabular osteolysis.

The technique was tested in four patients affected by secondary ostheolytic lesions. The patients were evaluated clinically (HHS, Womac, SF-12) and radiographically (X-ray and CT) at 18 months.

All the patients demonstrated a durable and significant improvement in terms of pain and restoration of function. The radiographic examinations (X-ray and CT) confirm these results. Complications (temporary increase in pain and fever) were only observed in one patient.

The preliminary results demonstrate the reliability and effectiveness of this procedure. Clinical results showed a significant reduction in pain and the capability of restoring function. The indications can be extended also to the acetabular lesion at a distance from the weight-bearing zone, reducing pain and the risk of pathologic fractures.

The technique was demonstrated to be effective and showed only minor and self-resolving complications. It is useful in patients in whom major surgery is contraindicated and clinical improvement is necessary to improve the quality of life.

In order to improve hydroxyapatite (Ha) quality as a bone substitute, two types of Ha were developed based on a new and original technique: Ha with graduated porosity (G-Ha) and porous “carbonated” Ha (C-Ha). Ha cylinders were implanted into the femoral diaphysis of NZW rabbits. Before implantation the materials were characterised by XRD, porosimetry, SEM and thermic and mechanical analysis. Macroscopic, radiographic and histologic analysis were performed on the specimens at standard intervals after surgery (1-3-6- and 12 months).

G-Ha proved to be morphologically more similar to bone tissue because of the graduated porosity that mimes the two natural components of bone (cortical-scarce porosity and spongious-high porosity). The C-Ha was chemically more similar to bone because of the CO₃- substitution, which is a normal substitute in natural bone.

Both materials achieved good mechanical strength, in particular the pseudo-cortical portion of G-Ha. Interconnected porosity was also observed in both materials. Newly formed bone appeared earlier in C-Ha (1–3 months). At 1 year C-Ha demonstrated quiescent bone and significant degradation. The G-Ha was scarcely reabsorbed but showed active osteogenesis in the surrounding living bone. Graduated porosity improved the mechanical interaction with bone over time, while the carbonation improved the temporal interaction and Ha resorption.

Porous Ha was found to be a promising bone substitute and also a reliable drug-delivery carrier.

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.

To evaluate the osseointegration enhancement, a consecutive randomized series of 50 on a total of 483 cementless titanium prostheses were prospectically studied. The features of the stem were the following: tapered, straight, low-profile neck, metaphyseal and hystmic fit, proximal 1/3 hydroxyapatite coated (HA) and titanium porous coated (PC). The acetabular component was hemispherical, titanium porous coated. A zircornia or Co/Cr head (28mm) was used. Female were 53% and average age 65. The general diagnosis was ostheoarthritis, congenital hip dysplasia, fracture, aseptic loosening, osteonecrosis, previous femoral osteotomy, previous pelvic osteotomy. Clinical objective assessment was based on the HHS. A patient oriented evaluation (Womac and SF12) was obtained. Radiological assessment was based on the Engh’s method. The general and prospectical group results have been evaluated.

In all the groups the HHS, Womac and SF12 questionnaires showed a statistically significant improvement in quality of life. Consistent evidence of proximal bone ingrowth were present in 100 % (HA) and 96 % (PC), stable proximal fibrous ingrowth in 4 % (PC). Cortical hypertrophy (50 % zone 3–5), stress shielding (56 % zone 1) and pedestal ( one case) were assessed. Nor osteolysis neither subsidence were identified. No significant general complications such as infections or periprosthetic fractures were observed. The use of HA seems to improve the mechanism of osseointegration and earlier clinical outcomes, even if this difference is not significant. Patient oriented evaluation and radiographic assessments confirmed the reliability of this cementless prosthesis. Less osteolysis could be predicted in the future, according to the reported results of other authors in the HA coated stems.

Bone Loss is the main problem in failed total hip arthroplasties. Revision surgery must be conformed to the degree of the bone loss. Since 1986, 330 cases of failed THA underwent to revision surgery. Different solutions were adopted according to Paprosky femoral defects classification. In type I, a primary cementless stem was implanted (23%). In type II and IIIa, were proximal fixation is still possible to achieve, Mid PCA-Howmedica (5%) and modular S-ROM-J& J revision stems (18%) were implanted. In all the other degree of bone loss (IIIb–IV) cementless distal fixation stems, Long PCA-Howmedica (17 %), Wagner-Sulzer (18 %) and modular (MP-Link, Profemur-Wright) (19 %), were used. Patients were clinically and radiographically evaluated by HHS and according to Engh’s criteria. Best results were observed in Type I group (HHS=90). Long and mid PCA stems presented poor clinical (HHS=60) and radiographical results and required re-revision in 15% of cases. Intermediate results were observed in Wagner prostheses. Modular revision stems showed best results although earlier F-U. (HHS=80). Of these, re-revision surgery was performed in two cases, one of which because of infection and the other one due to severe thigh pain.

Cementless modular stems seem to be the most suitable technique. Distal fixation associated with proximal fill permit to manage the majority of femoral bone defects minimizing bone grafts. The modular stems, allow to conform the design of the components to the bone defects permitting to achieve primary stability (press-fit), restoring the centre of rotation and muscles tension, reducing pain and restoring hip function.