Endoprosthetic replacement of the pelvis is one of the most challenging types of limb-salvage surgery, with a high rate of complications. In an attempt to reduce this and build greater versatility into the reconstruction process, a new type of pelvic endoprosthesis was developed in 2003, based on the old McKee-Farrar prosthesis. This study reviews the outcomes in 27 patients who had an ice-cream cone pelvic prosthesis inserted at two different specialist bone tumour centres in the United Kingdom over the past six years. The indications for treatment included primary bone tumours in 19 patients and metastatic disease in two, and six implants were inserted following failure of a previous pelvic reconstruction. Most of the patients had a P2+P3 resection as classified by Enneking, and most had resection of the ilium above the sciatic notch. The mean age of the patients at operation was 49 years (13 to 81). Complications occurred in ten patients (37.0%), of which dislocation was the most common, affecting four patients (14.8%). A total of three patients (11.1%) developed a deep infection around the prosthesis but all were successfully controlled by early intervention and two patients (7.4%) developed a local recurrence, at the same time as widespread metastases appeared. In one patient the prosthesis was removed for severe pain.

This method of treatment is still associated with high morbidity, but early results are promising. Complications are diminishing with increasing experience.

The aim of this study was to identify whether there was any difference in patient, tumour, treatment or outcome characteristics between patients with skeletal or extra-skeletal Ewing’s sarcoma. We identified 300 patients with new primary Ewing’s sarcoma diagnosed between 1980 and 2005 from the centres’ local database. There were 253 (84%) with skeletal and 47 (16%) with extra-skeletal Ewing’s sarcomas. Although patients with skeletal Ewing’s were younger (mean age 16.8 years) than those with extra-skeletal Ewing’s sarcoma (mean age 27.5 years), there was little difference between the groups in terms of tumour stage or treatment. Nearly all the patients were treated with chemotherapy and most had surgery. There was no difference in the overall survival of patients with skeletal (64%) and extra-skeletal Ewing’s sarcoma (61%) (p = 0.85), and this was also the case when both groups were split by whether they had metastases or not.

This large series has shown that the oncological outcomes of Ewing’s sarcoma are related to tumour characteristics and patient age, and not determined by whether they arise in bone or soft tissue.

Of 3000 patients diagnosed with primary malignant bone tumours and treated at our unit over the past 25 years, 234 (7.8%) were considered to be spindle cell sarcomas of bone (ie not osteosarcoma, chondrosarcoma, Ewing’s, chordoma or adamantinoma). We have analyzed their management and outcomes.

The diagnosis of these cases varied with fluctuations in the popularity of conditions such as MFH, fibrosarcoma and leiomyosarcoma with the passage of time. Treatment was with chemotherapy and surgery whenever possible. 36 patients had metastases at diagnosis and 17 had palliative treatment only because of age or infirmity. The most common site was the femur followed by the tibia, pelvis and humerus. The mean age was 45 and the mean tumour size 10.2cm at diagnosis. 25% of patients presented with a pathological fracture. Chemotherapy was used in 70% of patients the most common regime being cisplatin and doxorubicin. 35% of patients having neoadjuvant chemotherapy had a good (> 90% necrosis) response. The amputation rate was 22% and was higher in patients presenting with a fracture and in older patients not having chemotherapy.

With a mean follow up of 8 years the overall survival was 64% at 5 yrs and 58% at 10 yrs. Adverse prognostic factors included the need for amputation, older age and poor response to chemotherapy as well as a pathological fracture at presentation. The few patients with angiosarcoma fared badly but there was no difference in outcomes between patients with other diagnoses.

We conclude that patients with spindle cell sarcomas should be treated similarly to patients with osteosarcoma and can expect comparable outcomes. The histological diagnosis does not appear to predict behaviour.

Introduction: Giant cell tumor (GCT) is a benign but locally aggressive tumor that primarily affects the epiphyses of long bones of young adults. Pulmonary metastases in giant cell tumor are rare. We report our experience of treating pulmonary metastatic GCT of bone over the last 24 years between 1984–2007.

Methods: A retrospective review of patients’ records and oncology database of patients with metastatic GCT

Results: We had 471 patients with GCT of bone out of which 7 patients developed pulmonary metastases (1.48%). Six patients following diagnosis and initial treatment and one with pulmonary metastases present at the diagnosis. There were 4 males and 3 females aged between 23 to 40 years (median, 27 years). All patients had GCT around the knee (distal femur/proximal tibia). All patients eventually required Endoprosthetic Replacement apart from one who was treated with curettage only. The time of pulmonary metastases from initial diagnosis was 16–92 months (median, 44.6 months). All patients who developed metastases in the postoperative period had thoracotomy for excision of the pulmonary metastases. Two patients received chemotherapy for control of the local recurrence. At an average follow up of 151 months (27–304 months), all patients were alive

Discussion: Pulmonary metastases have been reported as 1% to 9% in GCT. Because of its rarity, very little is known about the long-term outcome and the best treatment for the pulmonary lesions. The mortality rates recorded for patients with pulmonary metastatic GCT range from 0% to 37%. In our series the mortality rate was 0% and metastases 1.48%. It seems that surgical resection of pulmonary metastases gave excellent rate of survival.

Aim: To identify factors leading to the success or failure of extracorporeal irradiation and reimplantation of bone (ECIR).

Method: Review of experience of this technique since 1996 documenting successes and failures.

Results: 35 patients with a variety of malignant bone tumours underwent ECIR from 1996 up to 2007. The most common diagnosis was Ewings’ sarcoma (15) followed by osteosarcoma (9) and chondrosarcoma (5) with the most common sites being the pelvis (15) followed by the tibia (10) and humerus (3). The age range was from 7 to 66 and 8 were skeletally immature at the time of surgery. The bones were sterilised with a dose of 90Gy before reimplantation.

The overall patient survival was 69% at 5 years and 62% at 10 years. Local recurrence arose in 4 cases, 3 of whom already had metastatic disease. None of the LR arose in the irradiated bone. The rate of non union was 9% at the 58 osteotomies, the greatest risk being in the tibia. There were four graft fractures of which 3 needed fixation and all united. There is one case of convincing graft resorbtion after 12 years. Two patients developed infections but there have been none since the done was routinely immersed in antibiotics whilst being irradiated.

Conclusion: ECIR is a useful technique with very limited indications. In the majority of cases it works well. It appears particularly useful in pelvic resections and diaphyseal resections. Distal tibial reconstructions do worst. The irradiated bone needs reinforcing with either cement or a bone graft for best results.

The two week wait has been established as a potential means of diagnosing malignant tumors earlier and thus hopefully leading to improvements in outcome. There remains controversy as to whether these clinic achieve this end or whether they just speed up treatment of patients already diagnosed (eg by imaging)

Aim: The aim of this study is to evaluate the diagnoses of all patient referred with a suspicious soft tissue lump to a two week wait clinic, to assess the diagnostic ‘hit rate’ and how many of these had already had imaging leading to a possible diagnosis of malignancy.

Method: Review of the diagnoses and referral criteria for all patients referred to a soft tissue sarcoma early diagnosis clinic.

Results: ** patients were referred under the 2 week wait criteria with a possible soft tissue sarcoma. ** (**%) turned out to have a malignant diagnosis. Of these, *8 were STS, ** were other soft tissue malignancies and ** were bone malignancices (** being….) Of the patients with a malignant diagnosis, only ** were referred directly to this hospital as a two week wait without previous investigation. Of the remainder *8 had undergone imag-9ing prior to referral leading to a suspicion of malignancy and ** were referred after investigation at another hospital. The average size of STS diagnosed after 2 week wait referral was ** which compared with **cm in those not referred via this route over the same time period.

Conclusion: Patients referred to a soft tissue 2 week wait clinic had a **% risk of malignancy. Of these, ** were new diagnoses suspected purely on clinical as opposed to imaging grounds.

The purpose of our study was to examine the survival and functional outcome of endoprosthetic replacements for non-oncology limb salvage purposes. Although initially designed for bone tumours, such is the versatility of these implants they can be used to salvage failed joint replacements, peri-prosthetic fractures, failed internal fixation and non-union.

Thirty eight procedures were identified from September 1995 to June 2007 from a prospectively kept database, including 17 distal femoral replacements, 12 proximal femoral replacements, 4 proximal humeral replacements, 2 distal humeral replacements, 2 hemi-pelvic replacements and 1 total femoral replacement. The quality of patients’ mobility was used to assess functional outcome and the survival of the prosthesis was calculated using a Kaplan-Meier survival curve.

The Kaplan-Meier implant survival was 91.3% at 5 years, 68.5% at 10 years and 45.7% at 20 years. The limb salvage survival for all reconstructions was 75% at 10 years.

The best survival was as follows pelvic (n=0/2) and total femoral prostheses where there was no failure in either group (n=0/1). Distal femoral replacements survival was 91% at 5 years, a single humeral prosthesis failed at 11 years post surgery, and proximal femoral replacements had a survival at 87.5% at 5 years. Three implants failed, two as a result of infection and required staged revisions and 1 failed as a result of aseptic loosening. Two patients dislocated their proximal femoral replacements, both were treated successfully by closed reduction.

Endoprosthetic replacement appears to be effective and the medium term survival is encouraging. The aim of a pain free functional limb is achievable with this technique. The complication rates are acceptable considering the salvage nature of these patients. We recommend referral of complex cases to a tertiary centre with expertise in this type of surgery.

Endoprosthetic replacement of the pelvis is one of the most challenging types of limb salvage surgery with a high rate of complications. In order to try and decrease the high risk of complications and to allow greater versatility in the reconstruction options, a new concept of pelvic endoprosthesis was developed in 2003. Since then 20 of these ice cream cone pelvic prostheses have been inserted at our centre incorporating antibiotic laden cement around the prosthesis to minimize infection risk.

Aim: To review the outcomes of the ice cream cone prostheses and to learn lessons from this.

Method: retrospective review of records and Xrays of patients having an ice cream cone type prosthesis at our centre.

Results: 20 ice cream cone prostheses were inserted in the past 5 years. Six of the implants were inserted following failure of a previous pelvic reconstruction (one for hydatid disease, one following a excision arthroplasty for chondrosarcoma, three following failed pelvic EPRs). Of the primary tumours, there were 9 chondrosarcomas, 2 Ewings, one each of osteosarcoma, epithelioid sarcoma and GCT. All of the patients had at the least had a P2+P3 resection with most having resection of the ilium above the sciatic notch. The average age of patients at operation was 50.5yrs [range 13–81yrs]. Ten patients (50%) had one or more complication following surgery, of which dislocation was the most common, affecting 5 patients (25%), of whom two have permanent dislocations. Four patients (20%) developed a deep infection of the prosthesis but all had this controlled with early intervention. Two patients (15%) developed a local recurrence, both at the time of widespread metastases. Only one patient has had the prosthesis removed, for severe pain. There were six deaths, four due to metastatic disease and two from cardiovascular complications. The complication was significantly lower for Surgeon A (who did 15 of the 20 procedures).

Conclusion: This method of treatment is still associated with high morbidity but early results are promising. Complications are much lower with increasing experience.

Patients who undergo soft tissue sarcoma excision accumulate serosanguinous fluid, potentially resulting in a seroma. This can lead to wound complications and delay post-op radiotherapy.

The purpose of this preliminary report is to assess the impact of routine application of Tisseel sealant prior to closure.

We investigated whether the sealant Tisseel is effective as a sealing agent to reduce the duration and volume of serosanguinous fluid drainage. Results were compared with individually matched controls.

Patients were split into 2 groups: those receiving 10mls sealant and those not receiving the sealant. Efficacy was evaluated by the number of days required for wound drainage, the volume of fluid drainage and the length of stay compared with matched controls.

The preliminary findings suggest that application of the sealant reduced the duration and quantity of fluid drainage after excision of the STS, allowing earlier discharge from hospital.

We present this work to suggest that the members of the British Orthopaedic Oncology Society should consider using this in a randomised controlled trial setting to evaluate its efficacy nationally.

Chondrosarcoma is treated with respect by oncology surgeons, given that it is relatively resistant to chemotherapy and radiotherapy. The aim was to study the outcomes of surgery for chondrosarcoma and determine the role of initial surgical margins and local recurrence on outcome.

Electronic patient records were retrieved on all patients seen with chondrosarcoma of bone with a minimum of two years follow up. A total of 532 patients were seen with Chondrosarcoma between 1970 and 2006. Patients were excluded if they had initial treatment in another unit (20 patients), a subdiagnosis of dedifferentiated chondrosarcoma (due to very poor prognosis, 43 patients), metastases at presentation (30 patients), if they presented with disseminated metastases prior to local recurrence (12 patients) or were not offered surgery, leaving 402 patients in the study group.

The mean age was 48 years old (range 6–89 years) with the most commonly sites of presentation being in the pelvis in 132 patients (29%), proximal femur in 81 patients (18%), distal femur in 40 patients (9%) and proximal humerus in 40 patients (9%). Grade at presentation was grade 1 in 44%, grade 2 in 44% and grade 3 in 12%. Surgical margins were radical in 3%, wide in 44%, marginal in 29%, planned incisional in 13% and unplanned incisional in 11%. Local recurrence occurred in 87 patients (22%). Local recurrence rates were significantly different for surgical margins on Fisher exact testing (p=0.003), which held true even when stratified by presenting grade of tumour. Surgery for local control was successful in 62% of cases.

Complex relationships exist between surgical margins, local recurrence and survival. Long term survival is possible in 1/3 patients who have local recurrence in intermediate and high grade chondrosarcomas and therefore ever effort should be made to regain local control following local recurrence.

We have compared the cost:benefit ratio of the new type of non invasive extendable prostheses with the old type which required lengthening under general anaesthetic with an invasive procedure.

Over the past four years we have inserted 27 non invasive endoprostheses (cost £14,000). Two have failed to lengthen due to problems with the inbuilt motor. So far there have been no infections, no loosenings and no patient has required revision. The lengthenings are painless and take half an hour. In the past 25 years we inserted 175 extendable endoprostheses (cost £7,000). All lengthenings were performed under a general anaesthetic. The risk of infection was initially 20% at ten years but had decreased to 8%. Pain and stiffness arose in about 10% requiring physiotherapy or occasionally manipulation under anaesthetic.

Assuming the following costs (current NHS cost) are accurate and appropriate, then the non invasive extendable prosthesis becomes cost effective when Cost EPR < Cost old EPR + (Additional risk physio(P) x cost) + (additional cost x number of lengthenings (L)) + (additional cost of revision for infection x risk of infection (R)). 14000 < 7000 + (300 x P) + (1500 x L) + (20000 x R). Assuming a 10% need for physiotherapy, four lengthenings and a 10% risk of infection gives: 14000 < 7000 + (30) +(6000) + (2000) = 15030.

Given the high complication rate of the old type of extendable procedure and assuming there are few if any with the non invasive type, then the non-invasive endoprostheses becomes cost effective if more than three lengthenings are required. They are certainly more popular with parents and children alike!

Low grade central osteosarcoma is a rare intramedullary bone producing tumour. It accounts for only 1–2% of all osteosarcomas. Due to the indolent nature of low grade central osteosarcoma, achieving a correct and prompt diagnosis is the real challenge both from imaging and histology, particularly as it may resemble a benign condition, i.e. Fibrous Dysplasia.

We have reviewed 15 cases of low grade central osteosarcoma with long term follow-up (2 to 22 years) to identify problems in diagnosis and treatment and to assess outcome.

There were 7 females and 8 males with a mean age of 37 yrs (range 11 to 72 years); 13 cases arose in the lower limb (8 femur, 4 tibia, 1 os calcis), 1 in the pelvis and 1 in the upper limb. The average duration of symptoms prior to presentation was over 2yrs. A primary diagnosis of low grade central osteosarcoma was achieved for only 6 cases (4 open and 2 needle biopsies), in the other 9 the primary diagnoses were GCT, cystic lesion or fibrous lesion (both benign and malignant) and all of them had undergone treatment (usually curettage with or without bone grafting for this). Definitive treatment was with surgery attempting to obtain wide margins. Marginal excision was associated with local recurrence in three cases but there were no local recurrences in patients who had a wide excision, even in those with prior treatment. Only one patient has died following the development of multiple metastases after 9 years. The survival rate is 90% at 15 years.

We present this study to show the difficulties in diagnosing this rare type of osteosarcoma and to highlight the importance of wide surgical margins to obtain local control.

Aim: To investigate the effectiveness of silver coated titanium prostheses in preventing periprosthetic infection in a group of very high risk patients.

Methods: Periprosthetic infection is one of the main problems in limb salvage surgery, especially for tibial and pelvic prostheses or following revision surgery, particularly if it has been done for a previous infection. We have used silver coated prostheses in 21 cases on a named patient basis and have now assessed the results.

Results: Between July 2006 and June 2008 21 patients had a silver coated prosthesis inserted. 11 patients were having a second stage revision after a previous infection, 6 were having a pelvic prosthesis inserted, 3 were having a primary tibial replacement and one a one stage proximal tibial revision. Three patients developed a postoperative infection, two of the pelvic replacements and one infected revision (a total femur replacement). Of these only one patient required removal of the prosthesis (for overwhelming coliform infection in a pelvic replacement) whilst the other two infections both settled with antibiotics and washout.

Discussion: The anticipated risk of infection in this high risk group would have been around 20%. The actual infection rate was 14% but two of the infections completely resolved with relatively modest treatment. This suggests that the silver coating may not only have a role in preventing infection but also enhancing control of infection should it arise. There were no other side effects and we believe that these preliminary results are encouraging and should lead to a further evaluation of silver for preventing infection around prostheses.

Aim: To review our experience of managing patients with aneurysmal bone cysts (ABC)

Method: We reviewed the medical records and radiographs of all patienst with aneurismal bone cyst treated at our unit over a 25 year period. During that time the policy of the unit was to treat ABCs with biopsy/curettage without use of adjuvants or bone grafting. Patients were followed up with regular Xrays until healing had taken place. Local recurrences were again treated with curettage, occasionally supplemented with embolisation or bone grafting.

Results: 237 patients (128 female, 109 male), with a median age of 14 yrs (range 1 to 76) received treatment. The cyst size varied from 1 to 20 cm and the median duration of symptoms was 16 weeks (range 0 to 8 yrs). The most common sites were the tibia (55) followed by the femur (41) then the pelvis (29) and humerus (27). 35 (15%) of the patients presented with a pathological fracture. Primary treatment was by curettage alone in 195, curettage and bone grafting in 7, aspiration and injection of steroids or bone marrow in 7, excision in 5 and observation alone in 17. The rate of local recurrence requiring further surgery was 12% with all local recurrences (bar one) arising within 18 months. Local recurrence was not related to site, age, sex or whether the patient had previous treatment or not. Local recurrences were managed with curettage alone in 19 of the 23 cases, with one having embolisation, one excision and 2 curettage and bone grafting. This was successful in all but 3 cases who were controlled with a third procedure.

Conclusion: The local control rate of ABCs with simple curettage is 88% which is as good as those published for any other technique. We recommend biopsy in all cases and limited curettage at the same time, many ABCs will heal with this simple procedure. Full curettage is needed for those showing no signs of healing within 4 weeks. Local recurrence is very unusual after 18 months.

Pelvic reconstruction after tumour resection is challenging. Pelvic replacements are usually custom made at considerable expense and then need very careful positioning at the time of surgery. They have a very high rate of complications with up to 30% risk of infection and 10% dislocation. In 2003 we developed a new type of pelvic replacement which would be simple to make, simple to use and which would hopefully avoid the major complications of previous pelvic replacements whist being versatile to use even when there was very little pelvis remaining. The concept is based on the old design of Ring stemmed hip replacement and has become known as the ice-cream cone prosthesis. It is inserted into the remnant of pelvis or sacrum and is surrounded by bone cement containing antibiotics. One of the main advantages is it’s flexibility, allowing insertion after resection at a variety of levels. It is also suitable for patients with metastatic disease.

We have inserted 12 of these implants in the past 4 years, resolving very difficult reconstruction problems. There was one case that became infected but was cured with washout and antibiotics. In one patient there was excessive leg lengthening resulting in a sciatic and femoral nerve palsy and the prosthesis had to be revised. All patients can walk with one stick or less.

These results are encouraging and suggest that this versatile implant may be the way forward for pelvic reconstruction because of it’s flexibility of use and low complication rate.

Introduction: Parosteal osteosarcoma is a rare, mostly low grade tumor arising from the surface of the bone. The aim of the study was to establish risk factors for local recurrence (LR) and death.

Method: Retrospective review of a prospectively collected database with complete up-to-date follow up.

Results: 63 patients were diagnosed and treated at our centre from 1978 to 2007. The most common site was the femur (37) followed by the tibia (10) and humerus (9). The median size was 7cm (2 – 16). At the time of diagnosis 27 (43%) were low grade, 13 (21%) were low grade but had invaded the medullary canal and 8 (13%) had a high grade component; the data was missing in 15 patients (24%). All patients were operated.

LR arose in 11 patients (17.5%) at a mean of 38 months and was related to surgical margins. There were no LR in the 26 wide resections, but the risk of LR was 20% in those with a marginal and 46% in those with an intralesional excision. LR appeared as a higher grade than the primary tumor in 3 patients (27%).

9 (14.3%) patients developed metastases at a median of 22 months (6 – 123). Five patients developed both LR and metastases. Seven patients died from the tumor, 2 patients are alive with metastatic disease.

None of the patients with a low grade tumor and wide or marginal margins died of tumor, but 2 patients (18%) operated intralesional died of tumor.

Discussion: There was a statistically significant relationship between surgical margins and LR (p< 0.001). All patients with low grade parosteal osteosarcoma operated with wide margins have been cured. LR appeared often in higher grade than the primary tumor. Patients with low grade tumor and intralesional margins had 18% risk to tumor-ralated death.

Aim: To review our experience of managing patients with aneurysmal bone cysts (ABCs).

Method: We reviewed the medical records and radiographs of all patients with ABCs treated at our unit over a 25 year period. During that time the policy of the unit was to treat ABCs with biopsy/curettage without use of adjuvants or bone grafting. Patients were followed up with regular Xrays until healing had taken place. Local recurrences were again treated with curettage, occasionally supplemented with embolisation or bone grafting.

Results: 237 patients (128 female, 109 male), with a median age of 14 yrs (range 1 to 76), received treatment. The cyst size varied from 1 to 20 cm and the median duration of symptoms was 16 weeks (range 0 to 8 yrs). The most common sites were the tibia (55), followed by the femur (41), then the pelvis (29) and the humerus (27). Thirty-five (15%) of the patients presented with a pathological fracture.

Primary treatment was by curettage alone in 195, curettage and bone grafting in 7, aspiration and injection of steroids or bone marrow in 7, excision in 5 and observation alone in 17. The rate of local recurrence requiring further surgery was 12% with all local recurrences (but one) arising within 18 months. Local recurrence was not related to site, age, sex or whether the patient had previous treatment or not. Local recurrences were managed with curettage alone in 19 of the 23 cases, with one having embolisation, one excision and 2 curettage and bone grafting. This was successful in all but 3 cases who were controlled with a third procedure.

Conclusion: The local control rate of ABCs with simple curettage is 88%, which is as good as the results published for any other technique. We recommend biopsy in all cases with limited curettage at the same time, and many ABCs will heal with this simple procedure. Full curettage is needed for those showing no signs of healing within 4 weeks. Local recurrence is very unusual after 18 months.

Of 3000 patients diagnosed with primary malignant bone tumours and treated at our unit over the past 25 years, 234 (7.8%) were considered to be spindle cell sarcomas of bone (ie not osteosarcoma, chondrosarcoma, Ewing’s, chordoma or adamantinoma). We have analyzed their management and outcomes.

The diagnosis of these cases varied with fluctuations in the popularity of conditions such as MFH, fibrosarcoma and leiomyosarcoma with the passage of time. Treatment was with chemotherapy and surgery whenever possible. 36 patients had metastases at diagnosis and 17 had palliative treatment only because of age or infirmity. The most common site was the femur followed by the tibia, pelvis and humerus. The mean age was 45 and the mean tumour size 10.2cm at diagnosis. 25% of patients presented with a pathological fracture. Chemotherapy was used in 70% of patients the most common regime being cisplatin and doxorubicin. 35% of patients having neoadjuvant chemotherapy had a good (> 90% necrosis) response. The amputation rate was 22% and was higher in patients presenting with a fracture and in older patients not having chemotherapy.

With a mean follow up of 8 years the overall survival was 64% at 5 yrs and 58% at 10 yrs. Adverse prognostic factors included the need for amputation, older age and poor response to chemotherapy as well as a pathological fracture at presentation. The few patients with angiosarcoma fared badly but there was no difference in outcomes between patients with other diagnoses.

We conclude that patients with spindle cell sarcomas should be treated similarly to patients with osteosarcoma and can expect comparable outcomes. The histological diagnosis does not appear to predict behaviour.

Low grade central osteosarcoma is a rare intramedullary bone producing tumour. It accounts for only 1–2% of all osteosarcomas. Due to the indolent nature of low grade central osteosarcoma, achieving a correct and prompt diagnosis is the real challenge both from imaging and histology, particularly as it may resemble a benign condition, i.e. Fibrous Dysplasia.

We have reviewed 15 cases of low grade central osteosarcoma with long term follow-up (2 to 22 years) to identify problems in diagnosis and treatment and to assess outcome.

There were 7 females and 8 males with a mean age of 37 yrs (range 11 to 72 years); 13 cases arose in the lower limb (8 femur, 4 tibia, 1 os calcis), 1 in the pelvis and 1 in the upper limb. The average duration of symptoms prior to presentation was over 2yrs. A primary diagnosis of low grade central osteosarcoma was achieved for only 6 cases (4 open and 2 needle biopsies), in the other 9 the primary diagnoses were GCT, cystic lesion or fibrous lesion (both benign and malignant) and all of them had undergone treatment (usually curettage with or without bone grafting for this). Definitive treatment was with surgery attempting to obtain wide margins. Marginal excision was associated with local recurrence in three cases but there were no local recurrences in patients who had a wide excision, even in those with prior treatment. Only one patient has died following the development of multiple metastases after 9 years. The survival rate is 90% at 15 years.

We present this study to show the difficulties in diagnosing this rare type of osteosarcoma and to highlight the importance of wide surgical margins to obtain local control.

Aim: To investigate the effectiveness of silver coated titanium prostheses in preventing periprosthetic infection in a group of very high risk patients.

Methods: Periprosthetic infection is one of the main problems in limb salvage surgery, especially for tibial and pelvic prostheses or following revision surgery, particularly if it has been done for a previous infection. We have used silver coated prostheses in 21 cases on a named patient basis and have now assessed the results.

Results: Between July 2006 and June 2008 21 patients had a silver coated prosthesis inserted. 11 patients were having a second stage revision after a previous infection, 6 were having a pelvic prosthesis inserted, 3 were having a primary tibial replacement and one a one stage proximal tibial revision. Three patients developed a postoperative infection, two of the pelvic replacements and one infected revision (a total femur replacement). Of these only one patient required removal of the prosthesis (for overwhelming coliform infection in a pelvic replacement) whilst the other two infections both settled with antibiotics and washout.

Discussion: The anticipated risk of infection in this high risk group would have been around 20%. The actual infection rate was 14% but two of the infections completely resolved with relatively modest treatment. This suggests that the silver coating may not only have a role in preventing infection but also enhancing control of infection should it arise. There were no other side effects and we believe that these preliminary results are encouraging and should lead to a further evaluation of silver for preventing infection around prostheses.