To date, all surgical techniques used for reconstruction of the pelvic ring following supra-acetabular tumour resection produce high complication rates. We evaluated the clinical, oncological and functional outcomes of a cohort of 35 patients (15 men and 20 women), including 21 Ewing’s sarcomas, six chondrosarcomas, three sarcomas not otherwise specified, one osteosarcoma, two osseous malignant fibrous histiocytomas, one synovial cell sarcoma and one metastasis. The mean age of the patients was 31 years (8 to 79) and the latest follow-up was carried out at a mean of 46 months (1.9 to 139.5) post-operatively.

We undertook a functional reconstruction of the pelvic ring using polyaxial screws and titanium rods. In 31 patients (89%) the construct was encased in antibiotic-impregnated polymethylmethacrylate. Preservation of the extremities was possible for all patients. The survival rate at three years was 93.9% (95% confidence interval (CI) 77.9 to 98.4), at five years it was 82.4% (95% CI 57.6 to 93.4). For the 21 patients with Ewing’s sarcoma it was 95.2% (95% CI 70.7 to 99.3) and 81.5% (95% CI 52.0 to 93.8), respectively. Wound healing problems were observed in eight patients, deep infection in five and clinically asymptomatic breakage of the screws in six. The five-year implant survival was 93.3% (95% CI 57.8 to 95.7). Patients were mobilised at a mean of 3.5 weeks (1 to 7) post-operatively. A post-operative neurological defect occurred in 12 patients. The mean Musculoskeletal Tumor Society score at last available follow-up was 21.2 (10 to 27).

This reconstruction technique is characterised by simple and oncologically appropriate applicability, achieving high primary stability that allows early mobilisation, good functional results and relatively low complication rates.

Cite this article: Bone Joint J 2013;95-B:1410–16.

Aim

We present the greatest study of patients with proximal fibula resection. Moreover we describe a new classification system for tumour resection of the proximal fibula independent of the tumour dignity.

The aim of this study was to define the treatment criteria for patients with recurrent chondrosarcoma. We reviewed the data of 77 patients to examine the influence of factors such as the intention of treatment (curative/palliative), extent of surgery, resection margins, status of disease at the time of local recurrence and the grade of the tumour. A total of 70 patients underwent surgery for recurrent chondrosarcoma. In seven patients surgery was not a viable option. Metastatic disease occurred in 41 patients, appearing synchronously with the local recurrence in 56% of cases. For patients without metastasis at the time of local recurrence, the overall survival at a mean follow-up after recurrence of 67 months (0 to 289) was 74% (5 of 27) compared with 19% (13 of 50) for patients with metastasis at or before the development of the recurrence. Neither the type/extent of surgery, site of tumour, nor the resection margins for the recurrent tumour significantly influenced the overall survival.

With limited survival for patients with metastatic disease at the time of local recurrence (0% for patients with grade III and de-differentiated chondrosarcoma), palliative treatment, including local radiation therapy and debulking procedures, should be discussed with the patients to avoid long hospitalisation and functional deficits. For patients without metastasis at the time of local recurrence, the overall survival of 74% justifies an aggressive approach including wide resection margins and extensive reconstruction.

There has been a substantial increase in the number of hip and knee prostheses implanted in recent years, with a consequent increase in the number of revisions required. Total femur replacement (TFR) following destruction of the entire femur, usually after several previous revision operations, is a rare procedure but is the only way of avoiding amputation. Intramedullary femur replacement (IFR) with preservation of the femoral diaphysis is a modification of TFR. Between 1999 and 2010, 27 patients with non-oncological conditions underwent surgery in our department with either IFR (n = 15) or TFR (n = 12) and were included in this study retrospectively. The aim of the study was to assess the indications, complications and outcomes of IFR and TFR in revision cases. The mean follow-up period was 31.3 months (6 to 90). Complications developed in 37% of cases, 33% in the IFR group and 4% in the TFR group. Despite a trend towards a slightly better functional outcome compared with TFR, the indication for intramedullary femur replacement should be established on a very strict basis in view of the procedure’s much higher complication rate.

Introduction: It is noted that infections make up the most feared complications of prostheses’ surgery in orthopaedic implants after resection of primary or secondary cancer of limb bones. The causes must be attributed to the entity of the skeletal resection and of surrounding soft tissues sacrifice, to the duration of surgery and to the pre-operative cycle of chemotherapy or radiotherapy. Infections of prostheses in oncology are caused mainly by bacteria present either in isolated strains or in poly-microbic associations, and most recently fungus infections have begun to be found, in immunodepressed patients. Candidemia makes up an important cause of systemic infections in immuno-compromised oncological patients, who received high doses of chemotherapy; moreover candidemia represents a high risk of hospital sepsis. It is noted that the behaviour of the Candida is interpreted through the production of a biofilm and then the inhibition of the production of the biofilm itself is translated into a potential antifungal effect. From the analysis of the literature a protective role carried out by the silver coating of the tumoural prostheses towards the bacterial infections is deduced. It is noted, in fact, the antimicrobiotic effect of medical devices coated in silver; in particular in studies conducted in animals favourable results were demonstrated on bacterial adherence of titanium devices coated with silver. The aim of the study was to evaluate in vitro the inhibition of the production of biofilm by different strains of Candida in the presence of titanium and titanium coated with silver.

Materials and Methods: Six strains of Candida were analyzed: 2 strains of C. albicans, 2 of C. tropicalis and 2 of C. parapsilosis. The fungal strains were stratified on discs of pure titanium, a material in which implants of tumoural prostheses are made, and furthermore on discs of titanium coated in silver, and the ability of the fungus to produce protective biofilm on different substratum was evaluated. All of the studies were conducted 3 times. The adherence to the biofilm was measured by semi-quantitative, colormetric and spettrophotometric methods according to standardized protocols.

Results: The spettrophotometric analysis demonstrated a statistically significant reduction of the production of biofilm by fungus strains that came in contact with titanium coated in silver compared to pure titanium in all of the strains that were examined, attested by the fact that the silver creates a micro-environment unfavourable for fungus growth.

Conclusion: The analysis of the results demonstrated that the Silver coating of the oncological prosthesis made an unfavourable micro-environment not only for bacteria, as has already been widely established, but also for fungus. For this reason we maintain that this coating constitutes a valid opportunity in oncological resections for those patients who, being treated with chemotherapy, radiotherapy and to long hospitalitations present an elevated risk of fungal infection in oncological resections. From the studies we conducted it appeared how fundamental the use of silver in tumoural prosthesis is in order to prevent contamination by fungal strains and how this use must be taken more and more into consideration to improve life expectancy of a particular and sensitive category of patients, especially oncological.

Early and late infections are the most uneventfull complications after tumor resection and implantation of a maegaendoprosthesis. Therefore, silver-coating was introduced by our department years ago with successful reduction in infection rates. After promising results in animal and Phase exclusion of side effects in our Phase I trial, we would like to share our knowledge about latest research, especially the actual results of the Phase II study. We included the results off all implanted silver-coated Megaendoprosthesis since introduction in our department. Implantation had to be more than 12 months ago to guarantee a acceptable minimum follow up for calculation of the infection rate. Actually our infection rate lies at 3,1% (N=131) in the prevention group (no previous infection in medical history) and at 19% (N=36) in our “Highest-Risk” and previous infection group. Still no side-effects could be noticed. In one case we examined retrieved samples of three silver-coated Megaendoprosthesis. Macroscopically a leopard shaped figures could be noticed on the silver-coated surface in shiny and dark areas after being implanted in an infected region. Electron microscopy pictures show still intact surface and remaining silver with dark staining. Biofilm formation coulod not be noticed, though some few dead single bacteria could be found without any signs of proliferation or matrix production after adhesion. Signs of biofilm couldn’t be seen anywhere. Despite the discoloration silver is still intact in these areas without any loss of antibacterial properties. Blisterings or even flaking off the silver coating cannot be noticed. The thickness of the silver was not thinned in a significant way leading to a breakdown after a few years.

Up to these days we have no experience in covering the whole prosthesis including the stem in human beings. Concerning osteointegration of silver-coated stems, our animal trial could not prove their effectiveness in comparison to titanium. Pull-out tests showed high significant discrepancies in osteointegration between titanium and silver coated stems in a dog model after a period of 12 months after implantation.

Summarizing we recommend silver as a safe adjuvant therapy in patients undergoing endoprosthetic reconstruction after tumor resection. Intramedullary use of silver can be done only in experimental cases and needs further changes in the technical design of the coating.

Although the recurrence rate of giant cell tumors of bone (GCTB) is relatively high exact data on treatment options for the recurrent cases is lacking. The possible surgical procedures range from repeated intralesional curettage to wide resection.

214 patients with histologically certified GCTB have been treated at the authors department from 1980 to 2007. 67 patients with at least one local recurrence were included in this study. The mean follow-up was 77.3 months. The data was evaluated according the re-recurrence rate with regard to the surgical procedure for the recurrence.

The mean time until the first local recurrence was 22.0 months; the mean number of recurrences per patient was 1.4. The recurrence occurred in 69.7 % (46 out of 66 patients) within the first two years. If after intralesional procedures (curettage or intralesional resection) no adjunct was used the re-recurrence rate was 58.8 % (10 out of 17 patients) and decreased to 21.7 % (5 out of 23 patients) if a combination of all adjuncts (PMMA + burring) was used. The likelihood of re-recurrence was reduced by the factor 5.508 which was clearly significant (p = 0.016). In case of wide resection no re-recurrence occurred. Seven patients (10.5 %) developed pulmonary metastases. Fourteen patients (20.9 %) finally received an endoprosthesis; 12 due to tumor recurrence, 2 due to secondary arthritis.

Recurrent GCTB can be treated by further curettage with additional burring and cementing with an acceptable re-recurrence rate of 21.7 %. The rate of patients finally needing an endoprosthesis is 20.9 %. Due to the high rate of pulmonary metastases recurrent GCTB may be considered as a severe disease.

Megaendoprotheses are widely used in the reconstruction of large bone defects in orthopaedic tumour surgery. The major complications (up to 36%) are periprosthetic infections. Persisting periprosthetic infections lead to secondary amputation up to 37% of the cases. One underestimated reason for persisting infections are subpopulations of S. aureus called “small colony variants” (SCVs). Aim of this study was to evaluate that silver ions might prevent or cure a periprosthetic infection caused by SCVs.

For testing the antimicrobial activity of silver-coated titanium we used a technique introduced by Bechert et al. Therefore an adhesion and proliferation assay was performed with clinical isolates of S. aureus SCV (A22616/3). We tested the adhesion and proliferation properties of S aureus SCV on stainless steel (steel), Cobalt-Chrome-Molybdenum-alloy (CoCrMo), Titan-Aluminium-Vanadium-alloy (TiAlVa) and silver-coated Titan-Aluminium-Vanadium-alloy (scTiAlVa).

Adhesion of S. aureus SCV is significantly reduced on scTiAlVa vs. steel (p> 0001). We could also demonstrate that the proliferation rate of scTiAlVa vs. all tested materials is significant (p> 0001) lower.

We concluded that silver-coating has an effective antimicrobial activity against S. aureus SCVs. Thus silver-coated megaendoprostheses are a good prophylaxis against persisting infections caused by S. aureus SCVs.

Several studies report a diminished BMD as a consequence of childhood cancer treatment. The aim of this study was to investigate the effects of an exercise intervention on BMD during treatment, since limited mobility is characteristic for cancer therapy and is a major determinant for bone loss.

We analysed DXA scans (Lunar Prodigy, GE Healthcare) of 53 patients (range 8 to 21 years at time of diagnosis) perioperatively (n=49), six (n=38) and twelve months (n=18) after surgery. Scans were performed for the established sites of the lumbar spine and both femora, as well as experimentally for both calcanei. Areal BMD was corrected to obtain volumetric BMD using the model of Kröger.

For both groups, areal and calculated volumetric BMD values were similar at the lumbar spine at time of surgery, as were the differences between affected and not affected femur and calcaneus. The six and twelve months postoperative measurements revealed higher volumetric and areal BMD at the lumbar spine for the intervention group, although significant differences were only found for volumetric BMD values six months postoperatively.

Furthermore, a comparison of both groups showed that the loss in bone density of the affected lower extremity was less pronounced for the intervention group: differences between affected and not affected femur were 9% to 73% higher in the femur and 20% to 29% higher in the calcaneus for the control group.

Previous reports dealing with diminished BMD in pediatric cancer patients were confirmed in this study. However, differences found in BMD between both groups indicate that an exercise intervention during treatment, consisting primarily of strength and endurance training, may inhibit bone loss in pediatric sarcoma patients. Furthermore, the calcaneal site may be an alternative when the determination of femur BMD is not feasible.

A revision of a first generation KMFTR prosthesis due to stem breakage is a problem oncologic surgeons are regularly faced with. We designed an adapter which allows us to connect new MUTARS components to the original KMFTR devices. Thus it is possible to bypass an exchange of the whole prosthesis.

We used this adapter in 10 patients. Time of revision was in average 16.6 years after primary implantation of the KMFTR prostheses. Reasons for revision were femoral stem breakage (n = 5), breakage of the tibial component (n = 3) and periprosthetic fracture (n = 2, one femoral, one tibial).

The femoral stem (3 cases) and the tibial stem (2 cases) as well as the tibial plateau and body (2 cases) could be replaced by MUTARS parts and conjoined with the remaining KMFTR devices. Three cases were converted to MUTARS total femur.

Postoperative complications were one aseptic loosening and one cone-dislocation. Pre-incidence function was restored in all cases. The average Musculoskeletal-Tumour-Society-Score was 82.9% of normal function.

The results show that the new adapter facilitates to restore pre-incidental extremity function by performing a relatively modest revision.

Infections are the most uneventfull complications after tumor resection and implantation of a maegaendopros-thesis.Silver-coating of megaendoprosthesis has become a regular procedure in our department since last year in tumor cases. Especially in revision cases with high risk of infection they play a major role in preventing adhesion of bacteria. The successful reduction in infection rates show the effectiveness of the coating but still leave the question “how much coating do we need?” and “how much coating can be tolerated.

Latest research concentrated on the coating of the stems, since they can still be the source of the infection if everything else is coated by silver already.

Summarised so far, our experience in a rabbit model, a phase I Trial in humans and prelimnary results in Phase II Trials in humans showed no toxic side effects.

Driven so far it seems to be sensible to extent the silver coating. So far, the coating is limited to all areas without joint movement or bone contact. An Animal trial was performed anylising the osteointegrative properties of an silver-coated stem versus an regular Titanium stem in 17 dogs. After 12 months of regular X-Ray Analysis a Pull-out test and a concentration analysis has been done.

Results showed high significantly (p< 0.001) an osteointegration in 8 out of 8 titanium stems with an average pull-out force of 3764 Newton (Range 1755– 5967 Newton). Silver-coated stems showed no signs of Osteointegration in all 9 out of 9 femurs. The average pull-out force was 21 Newton (Range 0– 186 Newton). A cemented control could resist a pull out force of 350 Newton. Analysis of the silver concentration directly in the first millimeter of the bone-implant interface and the second millimeter showed highly elevated silver levels.

The silver concentration in the bone-implant interface at Titanium stems ranged from 0.3 to 3502 parts per Billion (ng/g) compared to silver-coated stems ranging from 303 to 2.418.800 ppb parts per Billion (ng/g).

Discussion: Sharing the histologic picture and reactions of the osteoblasts to the silver-coating there are several possible reasons for failed osteointegration. We want o discuss wether these has to be considered as a toxic response or just an adverse reaction.

In summary, surgeons have to decide in the future how much silver they need in each individual case concerning intramedullary infection prophylaxis. The balance between loosening or infection should be based on long term expectations, taking into account that even after successful resection of a tumor an ongoning infection can lead to loosening of a limb or even life. Apart from intramedullary use, we recommend silver as a safe adjuvant therapy in all suited patients undergoing endoprosthetic reconstruction after tumor resection.

Because of the lack of a suitable in vivo model for giant cell tumors of bone little is known about their biological behavior and mechanisms of metastasis. No existing cell line contains all tumor components, so that testing of anti tumor agents is hardly possible. We therefore modified the chick chorio-allantoic membrane (CAM) assay for giant cell tumor of bone (GCTB).

Out of tumor tissue obtained during surgery of 5 patients a solution was produced. The solute was grafted onto the CAM at day 10 of embryonic development. The growth process was monitored by daily observation and photo documentation using in vivo microscopy. After 5 to 6 days of tumor growth the samples were fixed in formalin and further analyzed using standard histology (hematoxylin and eosin stains).

The tissue solute of all 5 patients formed solid tumors when grafted to the CAM. In vivo microscopy and standard histology revealed a rich vascularisation of the tumors. The tumors were composed of the typical components of GCTB including multinuclear giant cells.

A reliable protocol for grafting of human giant cell tumors onto the chick chorio-allantoic membrane was established. This model is the first in vivo model for giant cell tumors of bone. Further characterization of the growing tissue is necessary in further experiments.

Chondrosarcoma are rare malignant tumors. About the biological characteristics of chondrosarcoma is little-known [2]. Endothelin and its receptors are involved in regulating angiogenesis and metastatic dissemination [1]. The aim of this study is first to identify if chondrosarcoma are expressing endothelin-1 (ET-1) and the endothelin-receptors and thereupon to identify potential molecular markers for new target therapies. Another aim is to determine if endothelin is a prognostic factor in chondrosarcoma.

32 cases were investigated clinically and histopathologically. The expression of vascular endothelial growth factor (VEGF), Endothelin-1, Endothelin-Receptor-A (ETR-A) and Endothelin-Receptor-B (ETR-B) were determined. All data were analyzed by Fisher’s exact test (p< 0,05). All tumors show an expression of either ET-1, ETR-A or ETR-B. Chondrosarcomas with grade (G) I are mostly expressing less than 10-% ET-1 in cells, Chondrosarcomas G II are expressing in most cases between 10–50% and nearly all Chondrosarcoms G III more than 50%. In addition ET-1-expression is correlating with the histological grading. The patients also show a significant high metastatic dissemination probability at the time when tumor samples present more than 10%-storing ET-1-cells. The intensity of ET-1-expression is correlating with VEGF, which is the most important angiogenetic factor in tumors.

Chondrosarcomas are expressing ET-1, ETR-A and ETR-B. ET-1 seems to play a role in the angiogenesis of chondrosarcoma. Increased expression of ET-1 is accompanied with a high probability of metastatic dissemination. Endothelin receptor antagonists, which are used for example in prostate and breast cancer, can represent a potential therapy for chondrosarcoma [1]. Experiments on animals and clinical studies are required.

Pediatric patients with lower extremity sarcoma often experience long lasting restrictions concerning physical activity and walking due to the required off-loading of the limb and other consequences of surgeries. Activity promotion during treatment in addition to physiotherapy could improve patients’ activity levels and walking capabilities.

In the present study we investigated the ambulatory activity of 31 pediatric patients (13.7 ± 3.1 years, 1.63 ± 0.15 m, 51.9 ± 15 kg, 19.3 ± 3.7 kg/m2) with Osteosarcoma or Ewing sarcoma at the lower limb using the StepWatch™ Activity monitor (SAM; Orthocare Innovations, USA). Sixteen patients regularly underwent supervised exercise interventions during inpatient stays, 15 did not receive any additional intervention. Step activities were measured for seven consecutive days during home stays at five different points in time, to determine a possible transfer of activity to everyday life.

Patients without intervention assembled considerably less steps than those in the intervention group. Before surgery they reached 25.4% of the intervention group (total n=16), six weeks after surgery 40% (total n= 8), after three months 46% (total n=10), after six months 72% (total n=13) and after one year 90%. However differences only reached significance at the first measurement.

Data presented must be considered as preliminary. Not all patients could be measured at all appointments due to impaired walking ability. Nevertheless activity promoting interventions during inpatient stays seem to have a positive influence on patients’ daily walking activity. Though the differences between the groups are not significant they are considerable. Especially during treatment – as reflected by the first three measurements- patients could benefit from additional interventions exceeding typical therapy regimes. Interventions should be individualized to the patients’ capabilities. Conclusions concerning tumor location or surgical procedures are not yet possible. Future research should furthermore concentrate on the effects of activity promotion on other fields of well-being.

There is a high risk of venous thromboembolism when patients are immobilised following trauma. The combination of low-molecular-weight heparin (LMWH) with graduated compression stockings is frequently used in orthopaedic surgery to try and prevent this, but a relatively high incidence of thromboembolic events remains. Mechanical devices which perform continuous passive motion imitate contractions and increase the volume and velocity of venous flow.

In this study 227 trauma patients were randomised to receive either treatment with the Arthroflow device and LMWH or only with the latter. The Arthroflow device passively extends and plantarflexes the feet. Patients were assessed initially by venous-occlusion plethysmography, compression ultrasonography and continuous wave Doppler, which were repeated weekly without knowledge of the category of randomisation. Those who showed evidence of deep-vein thrombosis underwent venography for confirmation. The incidence of deep-vein thrombosis was 25% in the LMWH group compared with 3.6% in those who had additional treatment with the Arthroflow device (p < 0.001). There were no substantial complications or problems of non-compliance with the Arthroflow device. Logistic regression analysis of the risk factors of deep-vein thrombosis showed high odds ratios for operation (4.1), immobilisation (4.3), older than 40 years of age (2.8) and obesity (2.2).

Type BI rotationplasty is currently indicated for children with tumours of the proximal femur whereas type BIIIa rotationplasty is reserved for those in which the entire femur has to be removed. Our aim was to compare these two types of rotationplasty and determine whether the knee should be preserved in children with tumours of the proximal femur. We compared the post-operative complications, oncological outcome, range of movement, Enneking score and radiographs of six children, who had undergone type BI rotationplasty with those of 12 who had undergone type BIIIa rotationplasty.

Patients with type BI rotationplasty had a mean Enneking score of 21.6 compared with 24.4 in those with type BIIIa rotationplasty, and worse mean results in all of the parameters investigated. We conclude that type BI rotationplasty has a worse functional outcome and more complications than type BIIIa rotationplasty in children under the age of ten years.

Our aim was to investigate the outcome of excision of osteochondromas. Between 1994 and 1998, 92 symptomatic osteochondromas in 86 patients were excised. There were 40 women and 46 men with a mean age of 20 years (3 to 62). Of these, 56 had a solitary osteochondroma and 30 had multiple hereditary tumours. The presenting symptoms were pain (79.1%), swelling (23.3%), reduced range of movement (19.8%), cosmetic abnormalities (17.4%), and bursitis (12.8%). The most common site (37.6%) was around the knee.

Four patients had major complications (4.7%) including one intra-operative fracture of the femoral neck and three nerve palsies which resolved after decompression. Six patients had minor complications. Overall, 93.4% of the preoperative symptoms resolved after excision of the tumours. Excision is a successful form of treatment for symptomatic osteochondromas with a low morbidity.

In 45 patients we assessed the functional results and complications for three different reconstructive procedures after resection of primary tumors of the proximal humerus. An osteoarticular allograft was used in 11, a clavicula pro humero operation in 15 and a tumour prosthesis in 19. The glenoid was resected with the proximal humerus in 25 patients. The axillary nerve was resected in 42 patients.

The complication rate was lowest after reconstruction with a tumour prosthesis. The clavicula pro humero operation resulted in the most revisions. Cumulative survival rates for all the reconstructive procedures were similar.

At follow-up at two years the functional results for the three reconstructive procedures were the same with a mean functional rating of 79% (Musculoskeletal Tumor Society). Excision of the glenoid had no influence on the functional result.

Our findings indicate that the use of a tumour prosthesis is the most reliable limb-salvage procedure for the proximal humerus. The clavicula pro humero is an appropriate procedure if a prosthesis cannot be used.

We treated 58 patients with osteoid osteoma by CT-guided radiofrequency ablation (RF). In 16 it followed one or two unsuccessful open procedures. It was performed under general anaesthesia in 48, and spinal anaesthesia in ten. The nidus was first located by thin-cut CT (2 to 3 mm) sections. In hard bony areas a 2 mm coaxial drill system was applied. In softer areas an 11-gauge Jamshidi needle was inserted to allow the passage of a 1 mm RF probe into the centre of the nidus. RF ablation was administered at 90°C for a period of four to five minutes.

Three patients had recurrence of pain three, five and seven months after treatment, respectively, and a second percutaneous procedure was successful. Thus, the primary rate of success for all patients was 95% and the secondary rate was 100%. One minor complication was encountered.

CT-guided RF ablation is a safe, simple and effective method of treatment for osteoid osteoma.