Receive monthly Table of Contents alerts from Orthopaedic Proceedings
Comprehensive article alerts can be set up and managed through your account settings
View my account settings
Bone marrow contains cells, known as mesenchymal stem cells (MSCs), which have the ability to differentiate into osteoblasts. To create a 3-dimensional structure necessary for the reconstruction of tissue, cells need to be grown on a scaffold, for which hydroxyapatite (HA) was used, as it is osteoconductive. In living bone, increased extravascular perfusion increases new bone formation. Thus, these physiological conditions were reproduced in our novel bioreactor by perfusing MSCs seeded on porous HA scaffolds at a rate of 6ml/hr.
Therefore, this culture method could potentially be used to convert MSCs, isolated from patients’ bone marrow, into tissue-engineered bone.
The hypothesis was tested on three groups of graft, with eight samples in each group. Firstly, freeze-dried ethylene oxide treated bone graft was tested (group 2). For a negative control, allograft was heated to 70°C to denature the osteogenic proteins (group 1). The final group tested the effect of additional osteogenic supplements (100nM dexamethasone, 0.05mM ascorbic acid and 10mM (-glycerol phosphate) on MSCs on allograft (group 3).
Osteoblastic differentiation of MSCs was observed under scanning (SEM) and transmission (TEM) electron microscopy, and by measuring protein levels: alkaline phosphatase (ALP), osteopontin and type I pro-collagen over 14 days.
This study confirms that MSCs, derived from autologous bone marrow, could be used to increase the osteogenic potential of allograft, thereby increasing bony healing in patients.
This study examines the effect of injecting an inert synthetic lubricant, perfluoroalkylether (PFAE16350), as a mechanical joint lubricant to prevent the development of osteoarthritis in a surgically induced model of osteoarthritis in the adult guinea pig.
After wound closure, the animals were randomly assigned to 1 of 2 groups: (1) Single intra-articular injection of 1ml synthetic, sterile lubricant (PFAE16350) or (2) Control group with single intra-articular injection of 1ml 0.9% sterile saline.
At 9 weeks after surgery, after sacrifice, knee arthrotomy was performed, the presence of synthetic lubricant noted and the articular cartilages examined for macroscopic evidence of osteoarthritis. These cartilages were then fixed, embedded, sectioned, stained and graded histologically for osteoarthritis according to a modified Mankin scoring system.
Immunohistochemical studies were performed to assess for any inflammatory or cytotoxic effect by the lubricant.
Subjective macroscopic assessment of the medial tibial plateau osteophyte was noted to be larger and the articular surface more roughened in the control cases compared to the lubricated cases. Synthetic lubricant was noted at arthrotomy in all cases where it was injected.
Guinea-pig joints treated with the synthetic lubricant showed a mean modified Mankin score of 3.0 points compared with the guinea-pig joints treated with saline where the median modified Mankin score was 8.5 points (p< 0.001). There was no evidence of an inflammatory or cytotoxic response by immunohistochemical studies.
We hypothesised that in response to fracture, some integral osteoblasts are recruited via the circulation from remote bone marrow sites.
All animals had bone marrow harvested from their right tibia by saline flush. The mononuclear cells were isolated and culture-expanded in osteogenic medium for 3 weeks. Fluorescent reporter molecules were incorporated into the cell membranes, 24 hours prior to re-implantation of the cells into the fracture model. A 3 mm ulnar defect was preformed in all the animals. In groups I–III this was established 48 hours prior to cell re-implantation.
The animals were sacrificed at least 3 weeks after fracture surgery. Representative samples of the fracture callous, lung, liver, spleen and kidney were harvested from all animals and cryo-sectioned. Using confocal microscopy, the labelled cells were expressed as the average in 5 high power fields for each solid tissue. In addition, cyto-spins were made from blood and marrow and the cell number expressed as a percentage of the total cells.
In all sections, these labelled cells appeared on trabecular surfaces in an osteoblastic fashion, but occasionally they were surrounded by osteoid, corresponding to osteocytes.
A small number of labelled cells were found in the blood, bone marrow, lung, liver and spleen of all animals in groups I–III. No labelled cells were identified in the kidney tissue.
The thrombin-related peptide, TP508, is a synthetic 23 amino acid peptide, which represents the receptor binding domain of thrombin. TP508 mimics thrombin by interacting with receptors on cells involved in tissue repair. TP508 has been shown to enhance revascularization of injured tissue, and promote soft tissue wound healing, cartilage repair, and fracture repair. The aim of this study is to (1) test the effect of TP508 on bone regeneration during distraction osteogenesis; (2) study the chemotactic effect of TP508 on human osteoblasts.
Unilateral tibial osteoectomies were performed and stabilized with MX100 Orthofix lengthener in 5 male adult NZW rabbits. After 7 days, distraction was initiated at rates of 1.4 mm / day for 6 days. TP508 (100 μg/ml, n=2; 10 μg/ml, n=1) or saline (300 μl, n=2) was injected into the osteotomy / lengthening gap at days 1, 7 and 14 post surgery. Animals were sacrificed at 2 weeks after leg lengthening. Bone formation in the regenerate was assessed by radiography, quantitative computed tomography (pQCT) and histology. For chemotaxis studies, MG63 cells were cultured on glass cover slips for three days, and then inverted onto a Dunn chamber slide and sealed with dental wax. Gradients of TP508 (1, 10, 100 μg/ml) were added to the outer well and plain medium to the inner well. A sequence of images of the cells between the wells was taken via a CCD camera for 9 hours at interval of 10 minutes. Movements of individual cells were tracked and statistically analysed by a specially written Macro program. The Rayleigh test for unimodal clustering was used to determine the directional chemotactic movements.
The radiographic evaluation indicated a significant increase in new bone in the distraction regenerate in the TP508 treated groups at 1 and 2 weeks. pQCT images at 2 weeks demonstrated more advanced bone formation in the TP508 treated animals compared to the control. The mean total bone mineral density (BMD) of the regenerate, obtained from 3 slices was significantly greater (p = 0.019, t-test) in the TP508 treated group (BMD = 479.20 +/− 35.57 mg/ccm) than that in the saline control group (BMD = 355 +/− 2.83 mg/ccm). The histological evaluation supported the radiographic and the pQCT results. For chemotaxis study, no directional movements of the cells were found in the controls, whereas the MG63 cells were strongly chemotactic to TP508 at 1, 10 and 100 μg/ml concentrations.
This preliminary study shows that administration of TP508 enhances bone formation during distraction osteogenesis in the rabbit. The findings also show that TP508 has a chemotactic effect on osteoblasts, consistent with the effect of TP508 on fracture repair. A large animal study is in the process to confirm these findings and explore the underlying mechanisms.
Acute Achilles tendon pain is a common clinical entity, particularly in sportsmen and women. Fortunately, the majority of such pain is self limiting. However, there are a significant number of people for whom the pain becomes chronic and debilitating. A recent Cochrane review found that there was no randomised controlled evidence of an effective treatment for chronic Achilles pain. The aim of this study was to test the efficacy of shockwave therapy in a double-blind randomised controlled trial. The study has the approval of Local Research Ethics Committees.
Forty nine patients with Achilles tendon pain for a minimum of 4 months were included in the study. Patients were randomised to either shockwave therapy (n=27) or sham dose control therapy (n=22). Ultrasound was used to focus the shocks onto the affected area of tendon. The treatment group were given 2000 shocks at upto 1500mJ per shock, titrated to the patients pain tolerance. The control (sham) treatment was applied using the same parametres but with bubble-wrap interposition between the shockwave generator and the Achilles, to disperse the shockwaves. Each patient was treated once a month over 3 months. Primary outcome measure was pain on walking indicated on a 100mm visual analogue score (VAS) at 3 months. Secondary outcome measures included clinical and patient centred questionnaire scores. . An intention-to-treat approach was used for the analysis. Where patients had missing pain scores at 3 month follow-up, the last available pain score was carried forward.
The walking pain scores were very similar at baseline between the two groups. In the treatment group the mean (standard deviation) was 55.5mm (30.6) and in the control group 55.6mm (26.5). By 3 months, the pain scores had reduced in both groups to a mean (standard deviation) of 34.5 mm (34.2) and 50.3 mm (36.3). Although lower in the treatment group this difference was not statistically significant at the 5% level (t-test, p = 0.127, 95% C.I. : −4.7 to 36.2). No statistically significant differences were found with respect to any of the other clinical variables.
Two elderly patients in the treatment group sustained spontaneous rupture of the tendon after falls, during the course of the trial.
The results of this trial provided no evidence for the use of shockwave therapy in the treatment of patients with chronic Achilles tendinopathy. However, a treatment effect cannot be ruled out since the 95% confidence interval was wide and included a potential clinically relevant difference. The 2 cases of rupture suggest extreme caution in treating the elderly.
This study presents the 2 year migration results of the BHR femoral component using Roentgen Stereophoto-grammteric Analysis (RSA).
Metal-on-metal joint replacements have been reintroduced despite some concerns regarding the potential risks posed by soluble metallic by-products. We have investigated whether there are metal selective differences between the levels of genetic damage caused to a human cell line when cultured with synovial fluids retrieved from orthopaedic joint replacement prostheses at the time of revision arthroplasty.
These results highlight the importance of fixation techniques that rely on cancellous bone anchoring such as tensioned fine wire fixation in tibial plateau fractures.
The use of roentgen stereophotogrammetric analysis (RSA) in the assessment of total hip arthroplasty is well recognised as an accurate technique in the measurement of small movements of implants. The technique requires the insertion of tantalum beads into a stable location in the bone at the time of surgery. Failure of bead insertion leads to unstable extra-osseous beads that require to be excluded from the analysis. Previous studies have reported an incidence of extra-osseous beads in the proximal femur of between 2% and 13%. In order to further improve the accuracy of the RSA technique, we have developed a test criterion for exclusion of unstable osseous beads in RSA of total joint replacements.
Using specifically developed software each bead’s movement was determined relative to the rest of the beads in the bone segment. The bead movement was determined for radiologically identified extra-osseous beads, which were assumed loose, and for the remaining intra-osseous beads which were suitable for analysis. Analyses with a condition number greater than 100 were rejected. The rate of motion was calculated from consecutive examinations. Unstable beads were identified as those having a median rate greater than a given threshold. The sensitivity and specificity for detecting extra-osseous beads was calculated for different thresholds of median bead motion.
In 149 RSA hip study patients, 43 extra-osseous beads that could be analysed were identified and a group of 36 osseous beads were selected as a control group. This resulted in an optimum threshold of 0.36mm that gave a sensitivity of 89% and a specificity of 86% for detecting unstable (extra-osseous) beads. The remaining 1428 beads, which were assumed to be osseous, were then tested with this threshold, which gave a sensitivity of 84% and a specificity of 79%.
The median extra-osseous bead rate of movement at 6, 12, 18 and 24 months were 2.24, 0.78, 1.03 and 1.31mm respectively and for osseous beads were 0.27, 0.19, 0.18 and 0.19mm. As both groups of beads appear to show a “bedding in” period, with a higher median bead movement in the first 6 months, the test was repeated with the first 6 month period excluded from the criteria. An optimal threshold of 0.37mm was found to have a sensitivity of 73% and a specificity of 87% for identifying an extra-osseous bead.
While most radiographically classified osseous beads identified as unstable may be false-positives, it is probable that some are extra-osseous but not visibly so on radiographs. The specificity of this technique is likely to be further improved with the increased precision from digital scanning techniques. Tantalum beads in general appear to be relatively unstable in the first 6 months, consistent with the expected osteo-intergration of the bead. This new criterion for bead instability allows automatic exclusion of unstable beads increasing the reliability of the RSA technique both in future studies and retrospectively to existing data.
The use of designer scaffolds to deliver biologically active osteogenic growth factors such as recombinant human bone morphogenetic protein-2 (rhBMP-2) to the sites of tissue regeneration in for example orthopaedics, has tremendous therapeutic implications. The aims of this study were to generate biomimetic biodegradable porous osteogenic scaffolds using a supercritical fluid process to encapsulate rhBMP-2, and to examine the ability of the scaffolds to promote human osteoprogenitor differentiation and bone formation in vitro and in vivo.
The rhBMP-2 encapsulated in Poly(-lactic acid) (PLA) scaffolds (100ng/mg PLA) were generated using an innovative supercritical fluid mixing method. The bioactivity of rhBMP-2 encapsulated PLA scaffolds were confirmed by induction of the C2C12 promyoblast cell line into the osteogenic lineage as detected by alkaline phosphatase expression. No induction of alkaline phosphatase-positive cells was observed using blank scaffolds. BMP-2 released from encapsulated constructs promoted adhesion, migration, expansion and differentiation of human osteoprogenitor cells on 3-D scaffolds. Enhanced matrix synthesis and cell differentiation on growth factor encapsulated scaffolds was observed following culture of human osteoprogenitors on explants of chick femoral bone wedge defects in an ex vivo model of bone formation developed using the chick chorioallantoic membrane model. In vivo studies using diffusion chamber implantation and subcutaneous implantation of human osteoprogenitors on rhBMP-2 encapsulated scaffolds showed morphologic evidence of new bone matrix and cartilage formation in athymic mice as assessed by x-ray analysis, immunocytochemistry and birefringence. These studies provide evidence of controlled release of BMP-2 from biodegradable polymer scaffolds initiating new bone formation in vivo.
The generation of 3-D biomimetic structures incorporating osteoinductive factors such as BMP-2 indicates their potential for de novo bone formation that exploits cell-matrix interactions and, significantly, realistic delivery protocols for growth factors in musculo-skeletal tissue engineering.
Ultra high molecular weight polyethylene (UHMWPE) wear debris induced osteolysis is a major cause of long term failure of total hip replacements. Particles in the 0.1–1.0_m size range are believed to have greater osteolytic potential than larger wear debris. Crosslinked polyethylenes have been shown to have improved wear resistance compared to non-crosslinked materials on smooth counterfaces, however wear debris from cross-linked UHMWPE has been shown to be smaller than that produced from non-crosslinked materials. The aim of this study was to compare the wear, wear debris and biological activity of non-crosslinked and crosslinked polyethylenes when worn against smooth and scratched counterfaces.
Using PCR, bacterial DNA was identified on 12 of 40 specimens (30%) from STOTs. Of these 12, three were taken at the start of surgery and nine at the end of the surgery, equivalent to a 45% wound contamination rate (9 of 20). Only two specimens (5%), both taken at the end of surgery, were positive on enriched culture.
In LFOTs, bacterial DNA was identified by PCR on eight of 40 specimens (20%). Of these eight, two were taken at the start of surgery and six at the end of surgery, equivalent to a 30% wound contamination rate (6 of 20). None of the specimens were positive on enriched culture.
Transmitted and polarised light microscopy has been used in all cases.
Low positive swing phase load (<
100N) Positive swing phase load (300N, as per standard ISO 14242–1) Negative swing phase load, leading to microseparation and joint laxity.
All tests were carried out in 25% (v/v) new-born bovine serum, with gravimetric wear measurements completed every million cycles.
Finally a study was performed on 25 cadaver forearms that were available for imaging using DXA and the modified RA technique. BMD results showed good correlation (R=0.93, P< 0.001) with an error of less than 10%. The error is partly explained because during this part of the study a high-resolution anti-scatter grid was unavailable and a standard grid had to be used. Also some cadavers had previous fractures and dissection marks. Without these problems, it is expected that the error percentage would be significantly reduced.
Areal BMD (aBMD) is relatively poor at discriminating those patients at risk of hip fracture. This study tested the hypothesis that a measure of bending resistance, cross section moment of inertia (CSMI) and section modulus, derived from 3D peripheral quantitative computed tomography (pQCT) images made ex-vivo, would discriminate cases of hip fracture from controls better than areal bone mineral density.
The biopsies were from (n = 20, F) subjects that had suffered an intracapsular hip fracture. The control material (n = 23, F) was from post-mortem subjects. Serial pQCT 1mm thick cross-sectional images using the Densiscan 1000 pQCT clinical forearm densitometer were obtained, and matched for location along the neck. The image voxels were converted to units of bone mass, which were then used to derive the mass weighted CSMI (MWCSMI), section modulus and areal bone mineral density, (see Table).
The aBMD results showed that the difference between the means of the fracture cases compared to the controls was 9.9% (−0.061g/cm2; +0.0055g/cm2, −0.127g/cm2; 95% confidence interval). However, the MWCSMI was 29.5% (−5966mm4; −8868mm4,−3066mm4; 95% confidence interval) lower in the fracture cases compared to the controls, while section modulus was 32.5% (−242mm3; −133mm3, −352mm3 95% confidence interval) lower. When presented as Z scores the fracture cases had considerably lower section modulus Z scores (mean −1.27 SD, p=0.0001) than aBMD – Z scores (mean −0.5 SD, p=0.07). To simulate the forces experienced during a sideways fall, the model’s neutral axis was rotated by 210°. The results were similar for section modulus to those at 0°.
This study suggests that biomechanical analysis of the distribution of bone within the femoral neck may offer a marked improvement in the ability to discriminate patients with an increased risk of intracapsular fracture. Progress towards implementing this form of analysis in clinical densitometry should improve its diagnostic value.
We found the center of pressure of the ankle joint to be situated in the antero-medial quadrant, close to the center of the ankle joint. Distraction of the ankle joint by 5 mm eliminated any contact pressures at the ankle joint when the tibia was loaded up to 700N (one time body weight). When the joint was distracted by 10 mm no contact pressures were found in the ankle when loaded up to 1400N (two times body weight)
The center of pressure of the ankle joint is situated in the antero-medial quadrant. Distraction of 5 mm will eliminate ankle contact pressure up to one times body weight whereas distraction of 10 mm will eliminate contact pressures up to two times body weight.
The aim of this study was to compare the strain pattern in intact and resurfaced femurs using validated third generation composite femurs and rosette strain gauges.
Further tests were carried out in which an abductor load was included in the model. Testing was done at 600N and repeated thrice for each femur. The principal strains were calculated and compared with the the principal strains without the abductor load.
The motion of the shoulder complex, the scapulo-humero-thoracic rhythm, is an equilibrium between transmission of loads and positioning of the upper limb. This rhythm, which can be described by 12 spatial variables, is either responsible for, or affected by the genesis of shoulder pathology and trauma. Thus, imaging the articulations of the shoulder through a global range of motion is essential in aiding diagnosis, management decisions and interpreting operative outcome. As such, the objective of this study was to dynamically image the scapulo-humero-thoracic rhythm.
The subjects were seated between the toroid of the scanner and maximally slewn table on a customised tripod which both protects the target rings and provides a degree of comfort. Each subject was asked to carryout 4 movements; adduction to abduction in the scapular plane, internal rotation to external rotation at 0° and 90° abduction and flexion to extension. Each movement was carried out over a period of 5 seconds, enabling the acquisition of 20 volumes per movement.
Electron Beam Computed Tomography (EBCT) enables the scanning of a number of contiguous slices, each taking 50 msec. Previously this has facilitated real-time imaging and rendering of both cardiopulmonary function and colonography. A GE Imatron EBCT C300 scanner was used with a multislice sequence imaging protocol to collect 8 transaxial slices per volume by sweeping an x-ray beam sequentially over 4 tungsten target rings and recording x-ray intensity via two fixed detector rings after the reflected beam passes through the body.
Each slice was post-processed by semi-automatic segmention using Amira software, and reconstructed to produce three-dimensional volumes of the humerus, scapula, clavicle and selected ribs. Anatomical landmarks were then identified and the normal rhythm of the shoulder was described.
In conclusion, EBCT provides a quick and efficient method for direct realtime dynamic imaging of the shoulder girdle under normal conditions, the first time this has been achieved to the best of our knowledge. Not only do these reconstructions provide further input matter for preexisting and future computational shoulder models, but estabilishes an initial baseline for further clinical experience. As such, we hypothesise the ability of this modalitiy to image pathological and traumatic disruption to shoulder rhythm. The potential clinical application of this tool would include imaging of traumatic instability and impingement, facilitated by some minor ergonomic alterations to the apparatus.
The results have also been analysed for each part of the Constant Score – Pain, Activities of Daily Living, Range of Movement and Strength and these will be presented.
The model developed in this study intended to look at linear distraction, i.e. lengthening.
To obtain a synthetic material with similar passive tensile properties to that measured in lengthened soft tissue
To measure the effect of tensioned synthetic soft tissue on osteotomy motion and multi-planar stiffness during cyclic loading.
Soft tissue tension was simulated with the use of neoprene rubber sheeting, attached to the nylon rod by Jubilee clips, with a gap anteriorly or medially. Extensive tensile testing was performed to determine the visco-elastic behaviour of the rubber, which showed it to be consistent and reliable. Tension of a similar magnitude to lengthened muscle (35–125N) was achieved, and could be accurately predicted for certain distraction lengths.
The stiffness of the frame was calculated from osteotomy motion with various distraction lengths both with the rubber attached and without.
Statistical analysis used the Mann-Whitney U test.
Significant differences were identified between the 3 methods of “Strength” measurement, highlighing the need for a uniform method of carrying out the CS.
Subjects: Nine patients (6F, 3M), mean age 15 years, were operated on between 1994–2000. This heterogeneous patient group consisted of five cases of spinal dysraphism, one prune belly syndrome, one arthrogryposis, one myotonic dystrophy and one congenital myopathic dystrophy (muscle-eye-brain-syndrome). All patients were
Subjects: From a total of 35 patients with symptomatic Chiari I who underwent primary cranio-vertebral decompression, 13 had clinically detected scoliosis. Of these 13, 10 (7 males) had no other structural spine abnormality, which could influence the natural history of scoliosis and were included in this study. Mean age at diagnosis was 11.5 years (range 8.8– 15.9 years).
S
group I (n=12):uncoated titanium plate,
group II (n=12): PLLA coated titanium plate,
group III (n=12): titanium plate coated with PLLA + 3% Rifampicin and 7% Fusidic acid, group IV (n= 12): titanium plate coated with PLLA + 2% Octenidin und 8% Irgasan.
The plate, the contaminated soft tissues and the underlying bone were removed under sterile conditions after 28 days and quantitatively evaluated for bacterial growth. A stepwise experimental design with an “up-and-down” dosage technique was used to adjust the bacterial challenge in the area of the ID50 (50% infection dose). Statistical evaluation of the differences between the infection rates of both groups was performed using the two-sided Fisher exact test (p< 0.05).
Infections in total joint arthroplasty, particularly with multiresistant bacteria, are a serious problem. A new nanoparticulate silver cement had previously shown good biocompatibility combined with good in vitro antimicrobial activity against multiresistant bacteria.
The purpose of the current study was to evaluate the antibacterial activity of nanoparticulate silver cement against biofilm-building methicillin-resistant S. aureus (MRSA) in a rabbit model and to compare it to that of gentamicin-loaded cement.
Gentamicin cement or nanoparticulate silver bone cement was injected into the proximal half of one femur in 10 animals, respectively. Before hardening of the cement 107 or 108 colony forming units of MRSA with high gentamicin resistance were inoculated at the cement bone interface in 5 rabbits of each group. The animals were euthanized after 14 days and both the cement adjacent bone and the cement itself were studied using microbiological and histological methods. Infection was defined as positive culture growth from the bone and/or cement samples.
Infections rates were 100% for the gentamicin group (10 of 10 animals had infection) and 30% for the NanoSilver group (3 of 10 animals). Thus, nanoparticulate silver bone cement significantly reduced infection rates by 70%.
Nanoparticulate silver cement exhibited good antimicrobial activity in the prophylaxis of cement-related infections with MRSA and is therefore a promising alternative in total joint arthroplasty.
The aim of this study was to demonstrate that short course antibiotic therapy combined with surgical drainage and followed by oral antibiotic therapy is quite adequate and suggested a scoring system as a comfortable and reliable tool to adjust the route of drug administration.
Criteria for discontinuation of parenteral antibiotic Scoring criteriapoints
Clinical evaluation
A: improved active motion of the joint: l
B: Painless active motion of the joint: 2
C: improvement in A & B:3
Radiological findings
A: progressive osteolysis ormultifocal involvement: 0
B: absence of the above findings*: 1
Laboratory evaluation
A: drop of 50.00/mm3 in WBC count or return to normal range (5.000–10.000 /mni3): 0.5
B: drop in ESR of 30 mm/hr or return to level of 30 mm/hr or less: 0.5
Total score: 5
*Pure periosteal elevation received a score of 1.
Patients with a score > or equal to 4 would be switched to oral antibiotic.
The mean functional scoring between the short-term group and long-term group were similar P> 0.05.
Overall, excellent or good results were achieved in both groups. No fair or poor results were observed. The average hospital cost for a patient in long-term group was twice that of a patient in short-term group.
A decision on prolonging the duration of parenteral antibiotics should be based on a combination of clear clinical, laboratory, and radiographic criteria, such us the scoring system presented in this article.
13 cases were transferred to Bone Tumors Centers: 10 of them were lost at F.U. Among those who underwent amputation: in two of them, local recurrence was observed, and one deceased after two years. Another Patient deceased for non-related heart problems.
Aetiology is still unknown: there is no evidence for an initiating factor. About favouring conditions ( inflammation, lower limb,) data are not clear enough.
In limb preserving surgery, our experience suggests one-stage procedures, avoiding to re-create chronic inflammation near the site of cancer.
The aim of this study is to determine whether it is possible to stimulate bacterial detachment from surgical stainless steel and decrease the viability of the remaining adhering bacteria using block currents. Method: Bacteria were allowed to adhere from a flowing suspension of high ionic strength in a parallel plate flow chamber, after which the suspension was replaced by a bacterium free solution with 10 mM potassium phosphate buffer. Block currents of 15, 60 and 100 ìA with different frequencies (0.1 to 2 Hz) and duty cycles (5 to 50%) were applied to induce bacterial detachment.
The killing capacity of these current series can be up to two log scales depending on the current.
Hip septic arthritis requires prompt surgical decompression. The aim of this study is to evaluate the advantages and effectiveness of hip arthroscopy in alternative to arthrotomy.
Since 1996, 6 children affected by hip septic arthritis were treated by arthroscopy. The mean follow up was 7.5 years (8–7 years), 2 patients were female and 4 male, the mean age was 6.5 years (from 4 to 8).
Time from onset of symptoms to operative treatment ranged from 24 h to 4 days. The surgical procedure was performed with the patient in the supine position and the leg in slight traction, by means of a sopratrocanteri c portal. A standard 4.5 mm arthroscope with a 70° optics was used. A sample or articular fluid was harvested for bacteriological and gram stain examination. The joint was then washed out with 8–10 litres of saline solution. No drain was left inside and all the patients were treated by a guided antibiotic therapy post-op.
In all cases a grossly purulent fluid was aspirated. In 3 cases the gram stain showed a S. Aureus as responsible of the infection. No complications were attributable to the arthroscopy in the intra and post-op period. ESR, PCR and WBC count normalized after 3 days post-op in all cases. The mean period of hospitalisation was 8 days (from 5 to 13), the mean time of full recovery was 17 days (from 15 to 20). At 7 years of follow-up no recurrence was reported and the clinical evaluation showed no pain and no functional restriction of the operated hip.
Early surgical drainage is the main treatment for septic arthritis of the hip. Hip arthroscopy allows to completely remove the purulent fluid from the inside of the hip joint, by means of a large volume lavage and direct suction. Hip arthroscopy demonstrated to be an excellent alternative to arthrotomy for treatment of septic arthritis in children old enough to be safely arthroscoped, with a significantly less morbidity.
The aim of this investigation was to measure pharmacokinetics of a Gentacoll sponge in bone tissue by microdialysis.
Mercury intrusion porosimetry: In order to mimic bone cement and beads after prolonged stay in the human body (i.e. after initial release of the loaded gentamicin) samples were immersed for four and two weeks, in PBS. Immersed and not-immersed samples were compared.
Positron emission tomography (PET) with 2-deoxy-2-[18F]fluoro-D-glucose (FDG) has evolved from a research imaging modality to a clinical practice for the assessment of malignancies. FDG, a nonspecific tracer of increased intracellular glucose metabolism, has been found to accumulate not only in malignant cells but also in infection and inflammation foci.
Aim of the study was to evaluate the usefulness of FDG PET scan in patients with joint replacement.
Materials and
MOD-B with antibiotic powder and PMMA Cylinders (A-MB-C) have been placed in saline solution and plasma for 4 weeks, compared with cylinders made with PMMA and antibiotic. The mechanical resistance of A-MB-C to compressive test has been performed subsequently. About biocompatibility, A-MB-C were implanted in sheep’s Ilium. After 3 moths an histologic evaluation has been performed.
The MOD-B + antibiotic + PMMA have released the higher quantity of antibiotic for all the 4 weeks. The A-MB-C resistance has been of 13.6 MPa, the same resistance of cancellous bone in the man’s femur. The histological result with a fluoroscopic microscope has been an osteogenesis in the full section of the cylinders.
External fixation compression devices have been an excellent method for gaining fusion but, there is no documentation about its ability for obtaining adequate limb alignment with a stable fusion of the knee joint.
Postoperative radiographs have been evaluated to digitally measure loss of femoral and tibial bone stock using Engh radiological classification. Moreover, we have quantified tibiofemoral alignment and the section of bony fusion. Fusion of the knee joint was assessed with CT. Patients were interviewed and pain was graded using a Visual Analog Scale (VAS) and self-satisfaction as well as current health status using the 12-item social function survey form (SF12).
ENS was used for 28 cases (25.4%). Other surgical techniques, were the Ilizarov apparatus (41 cases, 34.4%), the Grosse-Kempf locked nail (18.4%), fibular osteotomy (11%) the retrograde nail (5%), others (6%). ENS is indicated in:
3 – non unions with focuses at least 5cm. From epiphysis.
2)- serious soft tissue and bone cortical damage.
3)- failure of previous treatment.
3 – hypertrophie non unions where infection is reduced /absent and ESR is negative.
ENS is not indicated in the following conditions:
focus near the epiphysis; severe bone loss; atrophic non-unions ;
3 – active stage of the infection.
In spite of point 4, the Authors used it in 5 cases with active osteomyelitis that could not be treated otherwise.
Aim of the study was to determine the accuracy of current imaging modalities, radiography, MRT, CT, leukocyte (LS), bone (BS), and Galium (Ga) scintigraphy, and FDG-PET, for diagnosing COM.
The success rate after 1 year was of 81.5% (22 of 27 patients): 90% success rate for methicillin-resistant Staphilococci (9/10) and 76.5% for methicillin-susceptible Staphilococci (13/17). The patients with infection due to S. aureus had a success rate of 83.3% (10/12). whereas for infections due to SCN was 80% (12/15). The success rate for hip prostheses infection was of 83.3% (15/18) and 77.8% (7/9) for knee prostheses infection. The overall success rate after two years of follow up today is 77% (17/22), two patients dead because of cancer.
We report good tolerance of high posology long term administration in documented osteoarticular indications if yeast colonization is properly monitored, and eradication rates are comparable to those reported in infections with susceptible bacteria.
Previous identification of the infective microorganism First-stage surgery including radical debridement and placement of «personalized» spacers. Specific antibiotic treatment during three months. Second-stage surgery including second debridement, withdrawal of the spacers, collection of samples for microbiologic and histologic study (including intraoperative PMN study). Implantation of prosthesis without use of cement.
Cement with antibiotics is not essential for prosthesis reimplantation when replacement is performed in two-stage. Outcome in patients treated according to this protocol is equal or superior to that of other technique options (eradication of the septic process for a mean of more than 5 years). Prosthesis survival results justify the exclusion of cement for reimplantation.
One potential source of infection is the biopsy procedure, particularly when is carried out of a referring centre. In fact up to 30 per cent of patients with soft tissues problems following a biopsy is reported. As an infected biopsy may make subsequent limb preservation surgery impractical, the greatest care should be taken in carrying out the biopsy.
The implantation of foreign materials (prostheses, grafts, acrilic cement, metallic devices, etc) as the duration of the surgical procedure, intraoperative bleeding, possible deep haematomas, presence of drains, increase the risk of infection. Also the importance of haematogenous spread from other sites of infection to joint pros-thesis is well estabilished.
It has to be also emphasized that if at any stage the patient has had local radiotherapy, the tissues may be fibrosed and avascular and unable to combat local infection effectively.
The Authors retain that the infection after major orthopaedic oncologie surgery could represent a serious threat to the implant and to the limb. The importance of meticolous asepsis practised at every stage has to be emphasized, together with prolonged use of prophylactic antibiotic, specially in immunosuppressed patients or chemotherapy.
A similar result was confirmed by Field et Al. in 1992.
In 1993, de Lalla et Al. compared the systemic administration of 800 mg teicoplanin with the regional administration of 400 mg teicoplanin, and found higher levels of drug in the tissues of the operative field after regional administration.
In 2000, the same authors enrolled 205 prostheses in a clinical trial to assess the efficacy of the regional prophylaxis with 400 mg teicoplanin, and did not record any prosthetic infection.
In 2001, Lazzarini et Al. reviewed 217 patients who received regional prophylaxis with 400 mg teicoplanin for TKA, and found 8 (2.9%) surgical site infections, mostly occurring in patients with previous TKA.
In 2003, Lazzarini et Al. compared the tissue levels of teicoplanin after systemic administration of 800 mg and after the regional administration of 200 mg. The tissue levels after regional administration were still higher than those after systemic administration.
We have treated a total of 82 patients, 78 of them where men and 4 women, between 18 and 58 years old. Most of the patients were included in, first in the 40–50 (21 patients) and second in the 30-40 (26 patients) years-old range. Out of the 82 patients, 64 had ostheomyelitis, 10 arthritis and 8 soft tissue infection. The first localization for the ostheomyelitis has been in tibia (30 cases) and in femur (8 cases). The etiology is distributed in: 32 infections after osteosynthesis and 27 after an open fracture. The germs mostly isolated were Gram positives: Staphylococcus coagula negatives (21), staphylococcus methicillin-sensitive(14) y enterococcus (5); Gram negatives: Pseudomona aeruginosa (14), Serratia (3), Enterobacter (2).
Polymicrobial infections (with constant presence of S. aureus and/or S. epidermidis) accounted for 8% of hip and 7% of knee prosthesis infections. Treatment was represented by prolonged antibiotic administration (at least 8 weeks) associated with surgical debridment inacute infections, and two-stage exchange in chronic infections. In 23 hip infections in patients in poor clinical conditions or in suspected persistence of latent infection a new prosthesis was not replaced and Girdlestone’s hip arthroplasty was performed.
From Mars 1997 till July 2003 we subsequent included 32 patients, 26 with a minimal follow-up of 2 years are presented in this study. We evaluated the results of the treatment prospectively. The inflammatory parameters; C-reactive protein, erythrocyte sedimentation rate and white blood cell count (before and after debridement) The Harris Hip Score and radiograms were monitored multiple times.
In 23 patients the infection did not re-appear. The C-reactive protein normalised from a mean of 103 (2–320) to lower than 5 at 2 years, the erythrocyte sedimentation rate from 72 (14–120) to lower than 10. The white blood cell count was not elevated.
In none of the cases radiological signs of loosening was found and the mean HHS was 88 (75–96) points.
However in 3 patients the infection did re-occur: once after 2.5 months with the same bacterium as the first infection, a Streptococcus, again treated with a surgical debridement. At present she is clinical free of infection at a follow up of 2 years. The 2 other re-infections occurred respectively after 9 and 10 months, once after a surgical treatment of a jaw abscess and once after an episode of diverticulitis. The cultures derived other bacteria, a streptococcus and an E. coli, than the first infection, both a Staphylococcus aureus. In both cases a two-stage revision was the choice of treatment.
The test group: Five hundreds and eighty consecutive patients undergoing orthopaedic surgery during the period May 1st 1998 to December 31st 1999 were studied. They underwent either of the following procedures: total primary hip replacement; total primary knee replacement; operations for trochanter-major fracture (using Hip Compression Screw); ankle fractures.