Introduction

Computer Tomography (CT) imaging has been limited to beam hardening artefacts until now. Literature has failed to describe sensitivity and specifity for loosening of endoprothesis in CTs, as metal artefacts have always influenced the diagnostic value of CTs.

In recent years a new technology has been developed, the Dual Energy CT. Dual Energy CT scanners simultaneously scan with two tubes at different energy levels, most commonly 100kVp and 140kVp. Furthermore pictures gained from Dual Energy CTs are post-processed with monoenergetic reconstruction, which increases picture quality while further reducing metal artefacts.

This promising technology has increased the diagnostic value preventing more radiation for the patients, for example in detection of kidney stones or to map lung perfusion. In the musculoskeletal imaging it has not been established yet and further clinical investigations are necessary.

Thus the aim of this study is to describe sensitivity and sensibility for endoprothesis loosening of this novel technology.

Septic arthritis is a therapeutic emergency with a high mortality rate (about 11%)(1). Inadequate treatment can cause permanent joint damage. Management of the septic arthritis includes prompt antibiotic treatment as well as joint-decompression and removal of purulent material(2). It is still discussed controversially and there is little evidence which surgical concept is preferable: arthroscopy with lavage and debridement or open arthrotomy with synovectomy(3,4). The aim of the study was to compare efficacy of arthroscopy and arthrotomy in patients with septic gonarthritis.

We evaluated 70 consecutive patients who underwent arthroscopy or arthrotomy at our clinic, because of a bacterial monarthritis of the knee between 2002 and 2010. Our primary outcome was the early recurrence of infection (> 3 months after surgery), which made a second surgery necessary. We compared patients who suffered reinfection and those who did not, in regard to the surgery type as well as potential confounders like comorbidity (measured by Charlson comorbidity index), age, body mass index (BMI), Gächter's -, Kellgren and Lawrence - and Outerbridge classification, duration of symptoms and inflammatory parameters. Furthermore we evaluated differences of the confounders between the surgery groups.

From the 70 patients 41 were treated arthroscopic and 29 with arthrotomy. In total eight patients (11.4%) had to undergo a second surgery because of early reinfection. The rate was significantly higher in patients treated with arthrotomy (n=6; 20.7%) compared to those treated with arthroscopy (n=2; 4.9%) (p=0.041). Whereas we found no significant influence of potential confounders between the reinfection group and the group where primary eradication was achieved. Patients who underwent arthrotomy were significantly older, had more comorbidities (both p<0.001) and higher grades of osteoarthritis according to Kellgren and Lawrence classification (p=0.023). In order to adjust the study population towards confounders we performed a subgroup analysis on patients of the second and third age percentile. When we repeated our analysis we still found a significant higher reinfection rate in the arthrotomy group (p=0.036). At the same time there were no differences in prevalence of confounders, neither between the two surgery groups, nor between the reinfection and the primary eradication group.

Patients with bacterial monarthritis of the knee who were treated with arthroscopy had a significantly lower reinfection rate than those treated with arthrotomy. As arthroscopy is the less invasive and more sufficient method it should be considered the routine treatment according to our data.

Introduction

The current investigation includes a retrospective review of the experience of five Institutions with distal femur megaprostheses for tumor over a twenty year period, to analyze the incidence and etiology of failure, using a new classification system based upon the failure modes.

Background

Modular endoprostheses today represent a standard treatment option in the management of musculoskeletal tumors of the lower extremities. Long-term results of these reconstructions, however, are often limited by the course of the underlying disease. We therefore report our experiences in cancer patients with megaprostheses of the lower limb after a minimum of 15 years.

The rising incidence of atraumatic fractures in patients either with Ewing's sarcoma or osteosarcoma years after chemotherapy revealed a growing population of childhood cancer survivors with a decreased bone mineral density (BMD) possibly due to a long-term effect of the chemotherapy. Therefore we started to screen our patients below 50y of age who were treated for bone malignancies between 1994 and 2009.

The first series of measurements included 15 patients – eight Ewing's sarcoma, three female and five male, with a mean age of 18y (±13SD), and seven osteosarcoma, two female and five male, with a mean age of 19y(±9SD). We screened the patients for deficits in their bone status using DEXA (dual-energy-x-ray-absorptiometry) to gain the T-and Z-Scores of the proximal femur and the lumbal spine. Additionally we took blood samples for endocrinological analysis and utilised a questionnaire to scan the patient's liefestyle. The mean time between diagnosis and investigation was 95months (±79SD) in Ewing's sarcoma and 105months (±54 SD) in osteosarcoma.

The results of the age and gender matched lumbal measurement (Z-Score) of the Ewing's sarcoma patients showed a reduction of the BMD in six cases (6/8), including three times osteopenia (3/8) and two times osteoporosis (2/8). The osteosarcoma patients presented a BMD-decline in four cases (4/7) with two times osteopenia (2/7) and one osteoporosis (1/7).

In the proximal femur six Ewing's sarcoma (6/8) and six osteosarcoma patients (6/7) showed a BMD-decrease including three osteopenic (3/8) and one osteoporotic (1/8) Ewing's sarcoma and four osteopenic osteosarcoma (4/7). We found two cases of pathologic fractures (2/15), one Ewing's sarcoma 29 months after diagnosis with a fracture of the distal femur and the proximal Tibia (1/8) and one osteosarcoma with a fractured distal femur after 72 months (1/7).

As presented in our case series osteoporosis after chemotherapy is an underestimated long-term effect of the chemotherapeutic treatment. In our series BMD-reduction seems to be independent of tumour-type and chemotherapeutic agent like MTX.

Aim

Accurate and reliable patient information plays a crucial role in the multidisciplinary treatment of malignancies helping to ensure compliance of the patients and their relatives with often long-lasting and stressful treatment. The English version of the online encyclopaedia Wikipedia has been recently reported to be the prominent source of online health information. However, there is little information concerning the quality of information found in Wikipedia.

Introduction: Infections associated with prosthetic joints cause significant morbidity and account for substantial costs for health care systems. The management of prosthetic joint infections is less standardized, because of the variable clinical presentations and the lack of data from randomized, controlled trials.

We evaluated the results of surgical one stage versus two stage exchange of patients diagnosed positive for prosthetic infection following total hip replacement in correlation with a classification described by Mc Pherson.

Material and Methods: 94 patients were diagnosed positive for prosthetic joint infection following total hip replacement in the years 1995 to 2004: gender distribution was 45 male and 49 female patients. 37 patients were treated with a one stage exchange, 57 patients underwent a two step procedure. Patients were further divided into two groups following the mentioned classification described by Mc Pherson as infection type I+II and III. Further characterisation was performed following systemic host grade (A versus B+C) and local extremity grade 1 versus 2+3.

Results: Eradication of prosthetic infection was achieved in 94, 5% (n=52) within the group of two stage exchange and 56, 8% (n=21) of patients treated with a one stage procedure. Outcome of patients following a one stage or a two step exchange was overall significantly different with p< .001. Further deviations between the described two procedures were noted in the subgroups following the classification described by Mc Pherson. A benefit of patients who underwent a two step procedure was seen according the severity of the classification following Mc Pherson.

Conclusion: Eradication rate of prosthetic joint infections differs statistically significant overall and in the subgroups following Mc Pherson in dependence of the surgical procedure. For this reason the individual surgical procedure should be geared to an algorithm, following the classification described by Mc Pherson.

Introduction: Prosthetic joint infections occur in 1–2 % following total knee replacement. Different options of treatment are described in literature with a lack of data from randomized, controlled trials.

We classified septic revision surgeries following total knee according to a classification published by Mc Pherson. Eradication rate of one stage versus two stage exchange was compared.

Materials and Methods: We included 74 patients who underwent septic revision surgeries following total knee replacement in the years 1998 to 2005. Gender distribution was 42 female and 32 male patients. The mean age at revision surgery was 71 years, at primary implantation mean 68,8 years.

Results: The eradication rate overall was 77 %, in one stage exchange 41.7% and in two stage procedures 86%. Multiple stage revision showed an eradication rate of 75%, necrectomy/debridement 50%, arthrodesis and amputation 100%.

Regarding Mc Pherson’s systemic grades classification the eradication rate for two stage exchanges was 85,7% in group A+B and 60%% in group C. One stage procedures achieved 0% eradication rate in group B and 60% in group C. Regarding Mc Pherson’s local extremity grade classification eradication rates within two stage revisions were 84% in group 2 and 75% in group 3. One stage revision achieved 40% and 0%.

Conclusion: Although two stage revision surgeries achieved better results regarding eradication rates then one stage revision surgery, results were statistically not significant. Reason could be a too small number of included patients for a significant statistical impact. The individual surgical procedure should orientate on the classification published by Mc Pherson.

In animal experiments antioxidants like Resveratrol, Quercetin-dihydrate and Selen-L-Methionine cause a growth rate decrease in synovial tissue and furthermore an inhibition of pro-infiammatory factors. We investigated the effect of these antioxidants on synovial fibroblasts of Osteoarthritis (OA) patients compared to Rheumatoid Arthritis (RA) patients.

Random biopsies of synovial membrane were obtained aseptically from joints of OA and RA patients. After in vitro expansion cells were cultivated until passage three, seeded in 96 well microtiterplates and treated with 0μM, 50μM, 100μM and 200μM of Resveratrol, Quercetin-dihydrate and Selen-L-Methionin. After 24 and 48 hours incubation cell proliferation assays and apoptosis FACS analysis were performed. Additionally woundhealing assays and photographic documentation of resettlement of synovial fibroblasts was accomplished.

The results of cell proliferation assays showed a highly significant reduction as well in OA and RA cells. In OA synovial fibroblasts 200μM of Resveratrol evoked a decrease of 72,3 ±1,7% (***), 200 μM of Quercetin-dihydrate induced a reduction of 16,11 ±3% (***). 200μM of Selen-L-Methionine evoked a decrease of 27,3 ±3,8% (***). In RA cultures 200 μM of Resveratrol evoked a decrease of 77,7 ±1,8% (***), 200μM of Quercetin-dehydrate induced a reduction of 20,38 ±15,3%(**), 200μM of Seleno-L-Methionine evoked a decrease of 23,3 ±4,8%(***)(n=20). The results of photographic documentation correlated with cell experiments. Analysis with untreated and treated OA and RA synovial fibroblasts for their content of apoptotic and necrotic cells by Annexin/7AAD staining displayed only few apoptotic cells. Caspase 3, a key mediator of apoptosis, was not activated in resveratrol-treated OA and RA synovial fibroblasts.

Resveratrol, Quercetin-dihydrate and Selen-L-Methionine showed a significant growth rate decrease in OA and RA synovial fibroblasts. In OA and RA the pharmacologic treatment with these antioxidants may be a therapeutic approach. Different apoptosis assays represented only few apoptotic cells. We therefore conclude that apoptosis is not the major pathway in resveratrol-treated synovial fibroblasts.

Objective: Metastases in the spinal column are a common manifestation of advanced cancer disease. Severe pain, pathologic fracture and neurologic deficit due to spinal metastases need adequate treatment. Considering oncologic aspects as well as quality of life, treatment decision should also include prediction of the survival period. In this study we analysed the scoring systems of Bauer, Bauer modified, Tokuhashi, Tokuhashi revised, Tomita, van der Linden and Sioutos, as well as the parameters they consist of, for their predictive value.

Methods: Two-hundred and fifty four patients with confirmed spinal metastases were investigated retrospectively (treatment 1998–2006; 62 received surgery, 189 only conservative therapy). The following factors were analysed: primary tumor, general condition (Kar-nofsky Performance Scale), neurological deficit, number of spinal and extraspinal bone metastases, visceral metastases, pathologic fracture. Survival period was calculated from date of diagnosis of the spinal metastases until date of death or last follow up (minimum follow-up: 12 months). For statistical analysis univariate and stepwise multivariate Cox regression analyses were performed.

Results: Median overall survival for all patients was 10.6 months. The following factors showed significant influence on survival in multivariate analysis: primary tumor (p< 0.0001), status of visceral metastases (p< 0.0001), and systemic therapy (p< 0.0001). Cox regression proved all scores significant in metric analysis. Distinguishing between the prognostic subgroups, only Bauer and Bauer modified showed significant results for this classification into good, moderate and poor prognosis. The other systems failed to distinguish significantly between good and moderate prognosis.

Conclusion: In our collective, Bauer and Bauer modified score prove to be the most reliable systems for predicting survival. We therefore want to propose the Bauer modified score (consisting of only four positive prognostic factors, excluding pathologic fracture) as valid for predicting survival and practicable for clinical use.

Introduction: Giant cell tumor of bone is a semimaligne tumor which locally recurs very often but rarely metastasises. En bloc resection of the distal radius with reconstruction using a homologeous allograft, curettage with PMMA blomb, and allograft arthrodesis are established methods. The aim of the study was to evaluate the functional outcome of our patients with the DASH-Score and the Mayo Wrist Score

Materials and Methods: In the last 7 years six patients were treated at our clinic due to a giant cell tumor of the distal radius. Two patients were primary treated with an en bloc resection. The other four were primary treated with curettage and filled up with PMMA cement plomb (Phenol was used in every case). In two of these cases a secondary en bloc resection was performed for local recurrence. For evaluation of function in daily live we used the DASH Score and the MAYO wrist score.

Results: The mean bone resection length was 5,25cm (5–6 cm).

All four patients treated with en bloc resection (primary or secondary) had no recurrence but in two out of that cases a re-operation was necessary because of non union.

At a mean follow up from 27 months (4–95) there were no recurrences or metastases at all

The flexion/extension of the wrist in currettaged radius was 60° and 80° compared with 38° and 68° in reconstructed radius. The pronation/suppination was 90°/90° in the currettaged ones versus 77°/77° in the allograft replaced ones.

The functional outcome evaluated with Mayo Wrist Score and DASH score showed an exellent outcome for both groups (84/7,7 Allograft < -> 85/10 Currettage)

Discussion: Functional outcome of distal radius resection reconstruction using an allograft is highly satisfactory compared with the literature, however we experienced a high risk for pseudoarthrosis. For prevention of non union simultan bone grafting at the index operation could be advisable.

The functional outcome proof no disadvantages in daily life and daily work compared to curettage. Thus allograft reconstruction of the distal radius represents a valuable alternative to arthrodesis.

Introduction: Articular cartilage injuries are very common, and if untreated can become symptomatic and progressively lead to premature osteoarthritis. It is well known that damaged cartilage has very limited potential to heal itself, and repair and regeneration of hyaline cartilage remain a clinical and scientific challenge. There are no pharmacological methods that can regenerate cartilage, and currently clinical treatments of debridement, chondrocyte transplantation and marrow stimulation have not been shown to restore consistently a durable articular surface. Tissue engineering and gene therapy concepts may improve cartilage repair by introducing cells, scaffolds, growth factors and other potential modulators of cartilage healing process. When analyzing cartilage treatment outcomes, traditionally we use macro- and microscopic assessment, immunohistochemistry, biochemical characterization etc. Recently, it has been postulated that biomechanical properties of newly formed cartilage are just as important, and novel methods of measurements have been proposed.

Materials and methods: 38 defects were created on weight-bearing part of the medial femoral condyle in sheep. The sheep were randomly assigned to one of four groups. In the bone marrow clot (BMC) group, the sheep were implanted with untreated autologous bone marrow clot that was aspirated from iliac crest of respected animal. In the bone marrow transduced with Ad. GFP (GFP) group, the sheep were implanted with autologous bone marrow clots genetically modified to over express green fluorescent protein (GFP). In the bone marrow transduced with Ad. TGF-β1 (TGF) group, the sheep were implanted with autologous bone marrow clots genetically modified to over express transforming growth factor-β1. Untreated sheep served as a control (defect without implant), and native cartilage served as positive control. Specimens were collected after 6 months and analyzed by single-impact micro-indentation (SIMI), atomic force microscope (AFM) and scanning electron microscope (SEM).

Results: SIMI and AFM measurements showed that repair tissue has greater Young’s elastic modulus then native cartilage. There was a statistically significant difference between TGF-β1, GFP and BMC groups. SEM analysis showed presence of structurally organized collagen molecules in TGF-β1, GFP and BMC groups.

Conclusion: The results of this study showed that it is possible to enhance cartilage repair process by means of genetically modified bone marrow. Furthermore, biomechanical data obtained with SIMI, AFM and SEM provided more detailed insight into articular cartilage function and structure, and in future may be of practical importance for a better understanding of both cartilage mechanics and cartilage disease progression.

Despite great progress in implant design, materials and new implantation techniques aseptic loosening is still the most frequent cause of implant failure in THA, which was found to be increased especially in patients with osteonecrosis of the femoral head (ON-FH). While a direct link between aseptic loosening and periprosthetic bone loss still remains elusive, there is plentiful evidence for a close association with early migration of implant components. Although the beneficial effect of bisphonates on periprosthetic bone mass is well established, little is known to date about their effects on implant migration. This is an important issue, because successful prevention of early implant migration would provide strong evidence of a beneficial effect on the survival rate of THA. Previously, Krismer et al. found that a total migration of the cup of ≥ 1mm and a subsidence of ≥ 1.5mm 2 years after surgery was highly predictive for aseptic implant failure of THA within 8 to 10 years.

Fifty patients with end-stage ON-FH were consecutively enrolled to receive either 4mg of ZOL or saline solution (CTR) in a double-blind fashion. Radiographs standardized for EBRA-digital analysis were performed at each follow-up exam at 7 weeks, 6 months, 1 year, and yearly thereafter. The minimum follow-up period was 2 years (median follow-up: 2.8 years). Migration of the acetabular and femoral components was analyzed with the EBRA-digital software (University of Inns-bruck, Austria) independently by 3 investigators fully blinded to randomization.

Within the placebo group, distal migration of the stem (subsidence) steadily increased up to −1.2mm ± 0.6 SD at 2 years after THA without reaching a plateau phase (P< 0.001, Friedman ANOVA). Less but a nearly curvilinear migration pattern was found for the acetabular components, with a transverse migration of 0.6mm ± 1.0 SD and a vertical migration of 0.6mm ± 0.8 SD at 2 years (P< 0.001, Friedman ANOVA). Treatment with ZOL effectively minimized the migration of cups in both the transverse and vertical direction (0.15 mm ± 0.6 SD and 0.06 mm ± 0.6 SD, respectively, P< 0.05, ANOVA), and a trend to a decreased subsidence was also found for stem migration (−0.91 mm ± 0.51 SD; P=0.11, ANOVA). In addition, total cup migration exceeding 1mm at 2 years was significantly reduced by ZOL in 8 patients (12 vs 4 in CTR vs ZOL, respectively) as was also found in 6 patients for subsidence (≥ 1.5mm in 9 vs 3 patients in CTR vs ZOL, respectively) (P< 0.05, Fisher’s exact).

This is the first clinical trial reporting that a single infusion of ZOL suffices to improve initial implant fixation in THA. Based on best evidence available to date, this new concept shows great promise of improving the long-term outcome in THA and should be given attention in long-term trial.

Chevron osteotomy for correction of symptomatic hallux valgus deformity is a widely accepted method. Full weight bearing in regular shoes is not recommended before six weeks after surgery. Low intensity pulsed ultrasound is known to stimulate bone formation leading to more stable callus and faster bony fusion. We performed a randomized, placebo-controlled, double-blinded study on 44 patients (52 feet) who underwent chevron osteotomy to evaluate the influence of daily transcutaneous low intensity pulsed ultrasound (LIPUS) treatment at the site of osteotomy. Follow up at six weeks and one year was done with plain dorsoplantar radiographs, halluxrmetatarsophalangeal-interphalangeal scale and a questionnaire on patient satisfaction. There was no statistical difference concerning all pre- and postoperative clinical features, patient satisfaction and all radiographic measurements (hallux valgus angle, intermetatarsal angle, sesamoid index, metatarsal index) except for the first distal metatarsal articular angle (DMAA). The DMAA showed statistical significant (p=0,046) relapse in the placebo group comparing intraoperative radiographs after correction and fixation (5,2 degrees) and at six weeks follow up (10,6 degrees). Despite potential impact of LIPUS on bone formation we found no clinical evidence for its influence on outcome six weeks and one year after chevron osteotomy for correction of hallux valgus deformity.

Introduction: Despite advances in radiotherapy and chemotherapy, metastatic disease of the spine remains a challenging situation for spinal surgeons. An individual therapy should be chosen to provide the maximum palliative effect (reduction of pain, restoration of stability and function) with a minimum of operative morbidity and mortality. Predicting prognosis is the key factor in selecting the proper treatment. Therefore, various assessment systems have been designed in order to provide a basis for deciding the course of treatment. Such systems have been proposed by Tokuhashi, Sioutos, Tomita, Van der Linden, and Bauer. The scores differ greatly in the kind of parameters assessed. The aim of this study was to evaluate the prognostic value of each score.

Patients and Methods: Eight parameters were assessed for 69 patients (37 male, 32 female): location, general condition, number of extraspinal bone metastases, number of spinal metastases, visceral metastases, primary tumour, severity of spinal cord palsy, and pathological fracture. Scores according to Tokuhashi (original and revised), Sioutos, Tomita, Van der Linden, and Bauer were assessed as well as a modified Bauer score without scoring for pathologic fracture.

Results: Nineteen patients were still alive as of September 2006 with a minimum follow-up of 12 months. All other patients died after a mean period of 17 months after operation. The mean overall survival period was only 3 months for lung cancer, followed by prostate (7 months), kidney (23 months), breast (35 months), and multiple myeloma (51 months). At univariate survival analysis, primary tumour and visceral metastases were significant parameters, while Karnofsky score was only significant in the group including myeloma patients. In multivariate analysis of all seven parameters assessed, primary tumour and visceral metastases were the only significant parameters. Of all seven scoring systems, the original Bauer score and a Bauer score without scoring for pathologic fracture had the best association with survival (P < 0.001).

Conclusion: The data of the present study emphasize that the original Bauer score and a modified Bauer score without scoring for pathologic fracture seem to be practicable and highly predictive preoperative scoring systems for patients with spinal metastases. However, decision for or against surgery should never be based alone on a prognostic score but should take symptoms like pain or neurological compromise into account.

Background: Aseptic loosening of implants is commonly associated with periprosthetic bone loss, and several authors aimed to preserve periprosthetic bone mass by treatment with bisphosphonates (BPs) in THA. While local application of BPs was argued to provide higher concentrations of bioactive drug at the component-bone interface, we hypothesized that a systemically administration of BPs will be sufficient for sustained effects on local bone metabolism due to local accumulation of the drug in freshly exposed bone mineral early after reaming during implantation. The high antiresorptive potential of zoldronic acid (ZOL) on osteoclasts will be sustained locally by re-attachment after release by osteoclast resorption during the remodelling cycle. While we were able to demonstrate beneficial effects of ZOL on early implant fixation, its local effects on bone metabolism is best reflected by monitoring the relative changes of biochemical markers during follow-up after THA. This is an important issue to be addressed, since there are no reliable data available but essential for a prove-of-concept.

Methods: Fifty patients with ON-FH were consecutively enrolled to receive randomly either 4mg of ZOL or saline solution (CTR) in a double-blind fashion one day after THA. The biochemical bone turnover markers C-terminal teleopeptides of collagen type I (ICTP), CrossLaps (CL), osteocalcin (OC), osteoprotegerin (OPG), soluble RANKL, as well as 25-hydroxyvitamin D (25OHD3) were measured from fasting blood samples before surgery and at 7 weeks, 6 months, 1 year, and yearly thereafter. One patient was lost and after excluding three patients with deficiency in renal function 22 and 24 patients were analyzed in ZOL and CTR, respectively, during a median follow-up of 2.8 yrs.

Results: Within the placebo group, the bone resorption markers ICTP and CL peaked at 7 wks, but continuously decreased thereafter beyond baseline levels. The bone formation marker OC also increased, but peaked at 6 months and stayed increased during the follow-up. Although there was only a transient effect of ZOL found in ICTP, CL rapidly decreased within 7 wks and remained depressed during the whole follow-up period (~ − 65% at 2 yrs, P< 0.0001). Similarly, OC was also depressed in ZOL but never reached significance compared to baseline levels (~ − 19%, NS). No differences or changes were apparent in 25OHD3 levels.

Discussion and Conclusion: The findings strongly support a predominant local effect of systemically infused ZOL over a whole-body effect. Furthermore, the data demonstrate the sufficiency of a single infusion of a single infusion of ZOL for a pronounced and sustained antiresorptive effect after THA, which is essential to preserve periprosthetic bone mass in an effort to prevent aseptic loosening.

Based on paleopathological findings there is evidence that primary malignant bone und probably soft tissue tumours accompanied mankind from the very beginning. Impressive findings of osteosarcomas have been reported from ancient Peru and medieval Hungary. Astonishingly a report exists on a 3rd century AD amputation of a leg affected by “cancer” and, even more amazing, on the successful reconstruction using a homologous limb transplant.

This “miracle” has been attributed to Saints Cosmas and Damian. According to the legenda aurea of Jacobo da Varragine the miraculous treatment of took place in 3rd century Rome. The saints amputated the leg of the Deacon Justinian and successfully transplanted the leg of a black African, who had died some hours ago. According to the legend the deacon was able to walk again and glorify his doctors. This legend inspired artists throughout the centuries as can be seen in a famous 16th century oil painting in Stuttgart’s Landesmuseum Württemberg. The twin saints Cosmas and Damian have been praised before for the first homoplastic limb transplant. The cause for amputation, however, was reported to be a “gangrenous leg” or a “diseased leg”. Looking at the original text of the legenda aurea, a different picture emerges, the cause for surgery being “cancer” of the leg – “…cui cancer unum crus totum còsumpserat”.

Also astonishing, at their time and in ours, the saints treated patients without taking any payment. It is not surprising that they were the most renowned of all medically inclined saints and were soon regarded as patron saints of medicine. From today’s medical view, neither resection margins according to Enneking nor a follow-up period were provided by the legenda aurea. It therefore remains elusive whether a local or systemic recurrence occurred. Nevertheless, Saints Cosmas and Damian may well be regarded as Europe’s first orthopaedic oncologists.

Epimetaphyseal lesions may occur within congenital dysplasia or can be linked to metabolic, inflammatory and systemic diseases. They can also be caused by trauma or be due to malign or benign neoplasms.

Our case-report concerns a 4-year old boy who was x-rayed the day after falling from a chair and twisting his right ankle. X-ray showed an epimetaphyseal lesion of about 2 cm in diameter, located eccentrically in the lateral site of the distal tibia. A unilamellar periostal reaction could be detected in the lateral slices. On MRI, the lesion seemed to be of chondromatous origin and showed smooth borders with no evidence of surrounding oedema. The adjacent epiphyseal plate appeared as untypically fragmented. In CT-scans, the ventrolateral cortical bone was partially perforated and the lesion showed a tender sclerotic border. Due to the benign aspect, we agreed upon radiologic controls in order not to harm the epiphyseal plate by biopsy. MRI follow-ups revealed a slight but continuous growth. The lesion assumed an increasingly eccentric, tongue-shaped configuration with simultaneously increasing calcifications and mineralisations. After 5 years of radiological surveillance, the patient showed no evidence of growth-disturbance and did not report pain, but an increasing feeling of pressure when wearing boots.

Traumatic causes as well as metabolic, inflammatory and systemic diseases can, considering the patient’s history and clinical status, be put aside. The benign aspect combined with the long-term follow-up rules out malignancies. A chondroid matrix with increasing areas of mineralisation imply the diagnosis of a chondromatous tumour, although radiomorphology does not support this assumption; especially not, if age, clinical presentation, eccentric epimetaphyseal location and the involvement of the epiphyseal plate are taken into account. Among the entities left for differential-diagnosis, a dysplastic process e.g. Dysplasia hemimelica, must be considered, although doubts remain. For confirmation of diagnosis, further radiological and clinical surveillance will be conducted.

Background: Desmoplastic fibroma (DF) of bone is a very infrequent non-metastasizing osseous tumour with local aggressive appearance. The tendency of local recurrence in published cases is high.

Case reports: We present the clinical and radiological data of a male (35 years) and a female (37years) patient suffering from desmoplastic fibroma. Although in literature spinal lesions are severity rare, in our database two lesions located in the spine (C6 and L4) were identified. The first disturbances have been variable: The lesion in C6 was an accidental finding due to a control examination of a thyroid-ca, whereas the relapse-tumour of the L4 induced lumbago and hypaesthesia of the left heel.

Due to the importance of the thyroid treatment it was decided to control the lesion in C6 in close intervals. The lumbar tumour was initially treated outside and the first relapse was marginal resected at our department 11 years after the first diagnosis. The bone alterations appeared radiographically lytic and cystic.

Discussion: The spine is an unusual location of desmoplastic fibroma which arises in 56% at the long tubular bones followed by the mandible. To our knowledge only a few cases are reported to be located in the spine. DF located spinal, is a very untypical tumour and initial symptoms can be very unequal. Due to this dissimilar symptoms and variable histological appearance the diagnosis can be tricky. At least marginal resection should be achieved because intraleasional resected lesions show a local recurrence of 43%.

Introduction: Rotating hinge knee prostheses are designed to provide a stable knee reconstruction when the intrinsic soft-tissue stability of the knee had been lost as a result of tumor resection, multiple knee replacements, trauma or surgical reconstruction. Instability is the main risk factor for implant’s dislocation. We performed a biomechanical analysis to establish the association between design of the central rotational stem (length and taper) and the implant’s stability, using a self constructed biomechanical apparatus on a test bench in the laboratory.

Materials and Methods: The lengths and tapers of the central rotational stem of three different rotating hinge knee implants (LPS/M.B.T. (DePuy)-cylindrical, length: 46mm, taper: 0°; S-ROM Noiles (DePuy) -conical, length: 46mm, taper: 5°; GMRS (Howmedica) -cylindrical, length: 47mm, taper: 0°) were measured using a self-constructed biomechanical testing device. The degree of tilting of the central rotational stem within the vertical post-in channel by extending the distraction was measured as well the maximum amount of distraction before the stem’s dislocation.

Results: The GMRS implant design was superior to the LPS/M.B.T. and the S-ROM Noiles implant design concerning stability and maximum amount of distraction before dislocation (38 vs. 27 vs. 26 mm). The GMRS system had a steep rising distraction-angular displacement curve until the dislocation at 38mm occurred while the laxity curve of S-ROM Noiles showed a poor increasement. Besides early high laxity it required only 26mm of distraction to dislocate.

Conclusions: Our conclusion is that rotating hinge prostheses with a short and markedly tapered central rotational stem have the highest instability/angular laxity at any given amount of distraction. Such knee prostheses should be used with caution in patients after excessive soft tissue resection. A long and cylindrical central rotational stem seems to prevent early instability and implant’s dislocation.