User testing to examine patient understanding of pharmacy generated medication labels.

OBJECTIVE: To examine patients' and carers' understanding of pharmacy generated medication labels. METHODS: A user testing questionnaire was conducted individually for 80 participants at 2 hospitals through a face-to face semi-structured interview. Pharmacy generated medication labels from different locations were grouped based on components into 4 different variations. Participants were asked to read and demonstrate understanding of the dose and frequency from 1 of the 4 variations for 4 prescription medications. Twenty participants for each variation were recruited so that demographic characteristics matched between variations. RESULTS: Overall, only 45% of participants were able to correctly understand the dose and frequency presented on all the pharmacy labels presented on medications. Medication labels with standardised timing performed better than other variations with 91% of participants able to determine the correct frequency. The use of numeric figures was understood by 80-90% of participants compared to the use of capitalised text (65-70%). Pharmacy generated medication labels that proposed one step were better understood than instructions that incorporated several steps. CONCLUSION/PRACTICE IMPLICATIONS: The study supports the use of simple, clear and explicit written instructions along with the use of numeric figures in pharmacy generated medication labels to achieve higher understandability in patients.

Epithelioid sarcomas: How important is loco-regional control?

AIMS: To investigate the impact of the method of treatment on the oncological outcomes in patients with epithelioid sarcomas managed at two international speciality sarcoma centres. METHODS: The databases of two centres were used to identify patients treated for epithelioid sarcomas between 1985 and 2012. Patient, tumor, treatment and outcome data was collected. RESULTS: There were 36 males and 18 females with a mean age of 38.3 years (range 9-79). Of 49 patients who were treated surgically, limb salvage surgery was carried out in 38 patients (78%) and limb amputation in 11 (22%). Of 49 total patients who underwent surgery for ES, 48 (98%) with ES had negative margin resection and 24 (49%) received (neo) adjuvant radiotherapy. Regional lymph node metastases developed in 5 (13%) patients. The five-year risk of local recurrence was 14%. The overall survival rate at five and ten years was 70% and 66% respectively. In multivariate analysis of patients with localized disease and negative margins, survival and risk of metastases was worse in those treated by amputation. CONCLUSION: This series has shown that although the rate of local recurrence is not influenced by the type of surgery, the risk of metastases is higher following amputation. This finding is likely due to patients with larger, deeper and more locally advanced tumors requiring amputation. However, we could not prove that immediate amputation was likely to affect overall survival.

What is the morbidity of a non-invasive growing prosthesis?

AIMS: Extendible endoprostheses have been available for more than 30 years and have become more sophisticated with time. The latest generation is 'non-invasive' and can be lengthened with an external magnetic force. Early results have shown a worryingly high rate of complications such as infection. This study investigates the incidence of complications and the need for further surgery in a cohort of patients with a non-invasive growing endoprosthesis. PATIENTS AND METHODS: Between 2003 and June 2014, 50 children (51 prostheses) had a non-invasive growing prosthesis implanted for a primary bone sarcoma. The minimum follow-up was 24 months for those who survived. Their mean age was 10.4 years (6 to 14). The incidence of complications and further surgery was documented. RESULTS: The mean follow-up was 64 months (20 to 145). The overall survivorship of the patients was 84% at three years and 70% at five years. Revision-free survival was 81.7% at three years and 61.6% at five years with competing risk analysis. Deep infection occurred in 19.6% of implants at a mean of 12.5 months (0 to 55). Other complications were a failure of the lengthening mechanism in five prostheses (9.8%) and breakage of the implant in two (3.9%). Overall, there were 53 additional operations (0 to 5 per patient). A total of seven patients (14%) underwent amputation, three for local recurrence and four for infection. Their mean limb length discrepancy was 4.3 mm (0 to 25) and mean Musculoskeletal Tumor Society Score functional score was 26.5 (18 to 30) at the final follow-up. CONCLUSIONS: When compared with previously published early results, this mid-term series has shown continued good functional outcomes and compensation for leg-length discrepancy. Infection is still the most common complication: post-operative wound healing problems, central line infection and proximal tibial location are the main risk factors. Cite this article: Bone Joint J 2016;98-B:1697-1703.

Ewing's sarcoma: only patients with 100% of necrosis after chemotherapy should be classified as having a good response.

AIMS: The purpose of this study was to review a large cohort of patients and further assess the correlation between the histological response to chemotherapy in patients with Ewing's sarcoma with the overall (OS) and event-free survival (EFS). PATIENTS AND METHODS: All patients treated for Ewing's sarcoma between 1980 and 2012 were reviewed. Of these, 293 patients without metastases at the time of diagnosis and treated with chemotherapy and surgery were included. Patients were grouped according to the percentage of necrosis after chemotherapy: Group I: 0% to 50%, Group II: 51% to 99% and Group III: 100%. RESULTS: The mean age at diagnosis was 16 years (1 to 62) and the mean follow-up was 9.1 years (six months to 32.6 years). The OS and EFS for the series were 75% and 65% at five years. There were significant differences in survival between the groups of necrosis: 0% to 50% (OS: 49% and EFS: 45% at five years, respectively) compared with 51% to 99% (OS: 72% and EFS: 59% at five years, respectively) and 100% (OS: 94% and EFS: 81% at five years, respectively) (p < 0.001). There were no significant differences in survival between patients treated between 1980 and 1989 compared with those treated between 1990 and 1999, and those treated between 2000 and 2012 (p = 0.55). CONCLUSION: Only patients with 100% necrosis after chemotherapy should be classified as having a good response to chemotherapy because they have significantly better rates of survival compared with those with any viable tumour in the surgical specimen. Cite this article: Bone Joint J 2016;98-B:1138-44.

Very long-term outcomes after endoprosthetic replacement for malignant tumours of bone.

AIMS: The aim of this study was to establish what happens to patients in the long term after endoprosthetic replacement for a primary malignant tumour of bone. PATIENTS AND METHODS: We conducted a retrospective analysis of a prospectively maintained database to identify all patients who had undergone an endoprosthetic replacement more than 25 years ago and who were still alive. Their outcomes were investigated with reference to their complications and need for further surgery. A total of 230 patients were identified. Their mean age at diagnosis was 20.7 years (five to 62). The most common diagnosis was osteosarcoma (132). The most common site was the distal femur (102). RESULTS: The mean follow-up was 29.4 years (25 to 43). A total of 610 further operations were undertaken, an average of 2.7 further operations per patient. A total of 42 patients (18%) still had the original prosthesis in place. The risk of amputation was 16% at 30 years (31 patients). Those without infection had a mean of 2.1 further operations (one to nine) while those with infection had a mean of 4.6 further operations (two to 11). The risk of infection persisted throughout the life of the prosthesis with a mean of 1% per year becoming infected. Of the 60 patients who developed an infection, 21 (35%) developed this following the primary procedure at a mean of 50 months, but another 19 developed this within a year of another surgical procedure. The risk of infection after any further surgery was 2.7%. The site with the highest risk of infection was the proximal tibia (43.3%). TAKE HOME MESSAGE: This study highlights the inevitable need for further surgery following first-generation endoprosthetic reconstruction, although in most cases, limb salvage is maintained. Late complications, especially infection, continue for the lifetime of the implant. Cite this article: Bone Joint J 2016;98-B:857-64.

Retrospective evaluation of the incidence of early periprosthetic infection with silver-treated endoprostheses in high-risk patients: case-control study.

We conducted a case-control study to examine the merit of silver-coated tumour prostheses. We reviewed 85 patients with Agluna-treated (silver-coated) tumour implants treated between 2006 and 2011 and matched them with 85 control patients treated between 2001 and 2011 with identical, but uncoated, tumour prostheses. In all, 106 men and 64 women with a mean age of 42.2 years (18.4 to 90.4) were included in the study. There were 50 primary reconstructions (29.4%); 79 one-stage revisions (46.5%) and 41 two-stage revisions for infection (24.1%). The overall post-operative infection rate of the silver-coated group was 11.8% compared with 22.4% for the control group (p = 0.033, chi-square test). A total of seven of the ten infected prostheses in the silver-coated group were treated successfully with debridement, antibiotics, and implant retention compared with only six of the 19 patients (31.6%) in the control group (p = 0.048, chi-square test). Three patients in the silver-coated group (3.5%) and 13 controls (15.3%) had chronic periprosthetic infection (p = 0.009, chi-square test). The overall success rates in controlling infection by two-stage revision in the silver-coated group was 85% (17/20) compared with 57.1% (12/21) in the control group (p = 0.05, chi-square test). The Agluna-treated endoprostheses were associated with a lower rate of early periprosthetic infection. These silver-treated implants were particularly useful in two-stage revisions for infection and in those patients with incidental positive cultures at the time of implantation of the prosthesis. Debridement with antibiotic treatment and retention of the implant appeared to be more successful with silver-coated implants.

Does amputation offer any survival benefit over limb salvage in osteosarcoma patients with poor chemonecrosis and close margins?

A poor response to chemotherapy (≤ 90% necrosis) for osteosarcomas leads to poorer survival and an increased risk of local recurrence, particularly if there is a close margin of excision. We evaluated whether amputation confers any survival benefit over limb salvage surgery (LSS) with narrow margins in patients who respond poorly to chemotherapy. We only analysed patients with an osteosarcoma of the limb, a poor response to chemotherapy and close margins on LSS (marginal/intralesional) or primary amputation: 360 patients (36 LSS (intralesional margins), 197 LSS (marginal margins) and 127 amputations) were included. Local recurrence developed in 13 (36%) following LSS with intralesional margins, and 39 (20%) following LSS with marginal margins. There was no local recurrence in patients who underwent amputation. The five-year survival for all patients was 41% (95% confidence interval (CI) 35 to 46), but for those treated by LSS with marginal margins was 46.2% (95% CI 38 to 53), 36.3% (95% CI 27 to 45) for those treated by amputation, and 28% (95 CI 14 to 44) for those treated by LSS with intralesional margins. Patients who had LSS and then developed local recurrence as a first event had the same survival as those who had primary amputation without local recurrence. Prophylactic adjuvant radiotherapy was used in 40 patients but had no discernible effect in preventing local recurrence. Although amputation offered better local control, it conferred no clear survival benefit over LSS with marginal margins in these patients with a poor overall prognosis.

Osteosarcomas in the upper distal extremities: are their oncological outcomes similar to other sites?

AIMS: To investigate whether the oncological outcomes of patients with osteosarcomas in the upper distal extremity are similar to other sites and assess if limb-salvage surgery is safe in this location. METHODS: The centre database was used to identify all patients with osteosarcomas in the lower humerus and distally between 1985 and 2012. Patient, tumor, treatment and outcome data was collected. RESULTS: Twenty-six patients were included in this study. There were 9 males and 17 females with a mean age of 33 years (9-90). Seventeen osteosarcomas were located in the forearm bones (65%), six in the distal humerus (23%), and three (12%) in the hand. The three most common sub-diagnoses were parosteal 7/21 (33%), fibroblastic 4/21 (19%) and osteoblastic osteosarcomas 3/21 (14%). 2 patients (8%) had Paget's disease and 19 patients (73%) had high-grade tumors. Local excision was carried out in 12 patients (48%), 4 patients underwent endoprosthetic replacement (16%) and 9 underwent amputation (36%). The overall risk of local recurrence was 4% in our series. The five-year overall survival rate was 67%, with low tumor grade and parosteal type of osteosarcoma being positive predictors of survival. CONCLUSION: This series has shown that patients with high-grade osteosarcomas of the upper distal extremities have a higher amputation risk than other limb sites but have favorable outcomes with limb-salvage surgery, comparable to other anatomical sites. Parosteal osteosarcomas in particular have a good prognosis.

The use of extracorporeally irradiated autografts in pelvic reconstruction following tumour resection.

The aim of this study was to evaluate the functional and oncological outcome of extracorporeally irradiated autografts used to reconstruct the pelvis after a P1/2 internal hemipelvectomy. The study included 18 patients with a primary malignant bone tumour of the pelvis. There were 13 males and five females with a mean age of 24.8 years (8 to 62). Of these, seven had an osteogenic sarcoma, six a Ewing's sarcoma, and five a chondrosarcoma. At a mean follow-up of 51.6 months (4 to 185), nine patients had died with metastatic disease while nine were free from disease. Local recurrence occurred in three patients all of whom eventually died of their disease. Deep infection occurred in three patients and required removal of their graft in two while the third underwent a hindquarter amputation for extensive flap necrosis. The mean Musculoskeletal Tumor Society functional score of the 16 patients who could be followed-up for at least 12 months was 77% (50 to 90). Those 15 patients who completed the Toronto Extremity Salvage Score questionnaire had a mean score of 71% (53 to 85). Extracorporeal irradiation and re-implantation of bone is a valid method of reconstruction after an internal hemipelvectomy. It has an acceptable morbidity and a functional outcome that compares favourably with other available reconstructive techniques.

Diaphyseal osteosarcomas have distinct clinical features from metaphyseal osteosarcomas.

AIMS: The aim of this study was to clarify the clinical features and outcomes of diaphyseal osteosarcoma. METHODS: Patients with newly-diagnosed high-grade osteosarcoma occurring in the long bone were eligible for this retrospective study. Clinicopathological information was collected from our database and compared with 36 diaphyseal, 405 proximal and 519 distal metaphyseal, and 14 whole bone osteosarcoma patients. Additionally, case-control study matching by age, gender, site, and metastatic status at diagnosis with 1:3 ratio of 36 diaphyseal to 108 metaphyseal osteosarcomas patients was also conducted. RESULTS: Five-year overall survival and metastasis-free survival of the three groups including diaphyseal, metaphyseal, and whole bone osteosarcoma patients showed significant difference (P = .029 and P = .013, respectively), although there is no difference for the survivals between proximal and distal metaphyseal osteosarcoma patients. Case-control study showed that patients with diaphyseal osteosarcomas had a significantly larger tumour (mean 13.5 cm vs 10 cm, P = .026), and demonstrated higher pathologic fracture rate (28% vs 12%, P = .033), superior 5-year metastasis-free survival (74% vs 40%, P = .0068), and slightly better 5-year overall survival (68% vs 46%, P = .074). Prognostic factor analysis showed that a pathologic fracture significantly decreased the survival of the patients with diaphyseal osteosarcoma. CONCLUSIONS: The current study showed that diaphyseal osteosarcoma has distinct clinical features from metaphyseal osteosarcoma having an increased risk of pathologic fractures but with favorable survival outcome.

Giant cell tumour of the proximal femur: Is joint-sparing management ever successful?

The purpose of this study was to assess whether the use of a joint-sparing technique such as curettage and grafting was successful in eradicating giant cell tumours of the proximal femur, or whether an alternative strategy was more appropriate. Between 1974 and 2012, 24 patients with a giant cell tumour of the proximal femur were treated primarily at our hospital. Treatment was either joint sparing or joint replacing. Joint-sparing treatment was undertaken in ten patients by curettage with or without adjunctive bone graft. Joint replacement was by total hip replacement in nine patients and endoprosthetic replacement in five. All 11 patients who presented with a pathological fracture were treated by replacement. Local recurrence occurred in five patients (21%): two were treated by hip replacement, three by curettage and none with an endoprosthesis. Of the ten patients treated initially by curettage, six had a successful outcome without local recurrence and required no further surgery. Three eventually needed a hip replacement for local recurrence and one an endoprosthetic replacement for mechanical failure. Thus 18 patients had the affected joint replaced and only six (25%) retained their native joint. Overall, 60% of patients without a pathological fracture who were treated with curettage had a successful outcome.

Massive endoprosthetic replacement for bone metastases resulting from renal cell carcinoma: factors influencing patient survival.

BACKGROUND: Surgery remains the main treatment of bone metastases due to renal cell carcinoma (RCC). We reviewed 135 patients treated with resection and endoprosthetic replacement (EPR) and examined clinico-pathological factors predicting survival. METHODS: Surgical and oncological outcomes were examined using a prospectively maintained database between 1976 and 2012. Survival rates were calculated by Kaplan-Meier method. Multivariate analyses were performed to investigate factors predictive of increased survival. RESULTS: At diagnosis, 81 patients had synchronous RCC and bone metastases and the remaining developed metachronous metastases after primary treatment for RCC. The majority were solitary tumours (75%) and 77% had ≥ one concurrent visceral metastases. The median age at surgery was 61 years old (IQR 53-69). The median follow-up was 20 months (IQR 10-43) and the overall survival was 72% at one-year. This declined to 45% and 28% at three and five-years, respectively. After adjustments for prognostic factors, there was an increased risk of death in patients with multiple skeletal metastases (HR = 2), ≥one visceral metastases (HR = 3) and local recurrence (HR = 3) (all p ≤ 0.01). Ten patients required revision (7%) and the risk of revision was 4% at one-year and remained low at 8% from two years postoperatively. CONCLUSION: Patients with solitary bone lesions and no visceral metastases should be considered for bone resection and EPR. As survival beyond one-year can be expected in a majority of patients and the risk of further surgery after EPR is low, patients with multiple skeletal metastases and visceral metastases should also be considered.

Outcome of soft-tissue sarcoma patients who were alive and event-free more than five years after initial treatment.

We evaluated the risk of late relapse and further outcome in patients with soft-tissue sarcomas who were alive and event-free more than five years after initial treatment. From our database we identified 1912 patients with these pathologies treated between 1980 and 2006. Of these 1912 patients, 603 were alive and event-free more than five years after initial treatment and we retrospectively reviewed them. The mean age of this group was 48 years (4 to 94) and 340 were men. The mean follow-up was 106 months (60 to 336). Of the original cohort, 582 (97%) were alive at final follow-up. The disease-specific survival was 96.4% (95% confidence interval (CI) 94.4 to 98.3) at ten years and 92.9% (95% CI 89 to 96.8) at 15 years. The rate of late relapse was 6.3% (38 of 603). The ten- and 15-year event-free rates were 93.2% (95% CI 90.8 to 95.7) and 86.1% (95% CI 80.2 to 92.1), respectively. Multivariate analysis showed that tumour size and tumour grade remained independent predictors of events. In spite of further treatment, 19 of the 38 patients died of sarcoma. The three- and five-year survival rates after the late relapse were 56.2% (95% CI 39.5 to 73.3) and 43.2% (95% CI 24.7 to 61.7), respectively, with a median survival time of 46 months. Patients with soft-tissue sarcoma, especially if large, require long-term follow-up, especially as they have moderate potential to have their disease controlled.

Hindquarter amputation: is it still needed and what are the outcomes?

A total of 157 hindquarter amputations were carried out in our institution during the last 30 years. We have investigated the reasons why this procedure is still required and the outcome. This operation was used as treatment for 13% of all pelvic bone sarcomas. It was curative in 140 and palliative in 17, usually to relieve pain. There were 90 primary procedures (57%) with the remaining 67 following the failure of previous operations to control the disease locally. The indication for amputation in primary disease was for large tumours for which limb-salvage surgery was no longer feasible. The peri-operative mortality was 1.3% (n = 2) and major complications of wound healing or infection arose in 71 (45%) patients. The survival at five years after hindquarter amputation with the intent to cure was 45%, and at ten years 38%. Local recurrence occurred in 23 patients (15%). Phantom pain was a significant problem, and only 20% used their prosthesis regularly. Functional scores were a mean of 57%. With careful patient selection the oncological results and functional outcomes of hindquarter amputation justify its continued use.

Oncological outcome of patients with deeply located soft tissue sarcoma of the pelvis: a follow up study at minimum 5 years after diagnosis.

AIMS: The treatment of pelvic soft tissue sarcomas (STS) presents one of the most challenging problems in musculoskeletal oncology because of the complex anatomy of the pelvis, late diagnosis and large tumor size. Our study was designed to determine the outcome and prognostic factors for survival and local recurrence in patients with pelvic STS located deep to the fascia and deemed suitable for curative surgical treatment. PATIENTS AND METHODS: Ninety consecutive pelvic STS patients with at least 5-year possible follow-up from diagnosis were studied. Mean age at diagnosis was 54 years. Mean follow-up and tumor size were 69 months and 13 cm, respectively. Histological grades were grade 3 in 51, grade 2 in 22 and grade 1 in 17 patients. Tumor locations were extra-pelvic or outside pelvic brim (n=67), intra-pelvic or within pelvic brim (n=10), and combined or involving both outside and within pelvic brim (n=13). RESULT: Surgical treatment was excision in 84 patients and hindquarter amputation in 6 patients. In 84 patients who underwent excision, surgical margin was wide in 21 patients, marginal in 33, and intralesional in 30. Radiotherapy was used for all high grade tumors. Disease-specific survival was 53.3% at 5 years. Local recurrence occurred in 23%. Development of local recurrence was related to surgical margin (p=0.03). Local recurrence, tumor histological grade and metastasis at diagnosis independently influenced disease-specific survival (p=0.0008, p<0.0001, p=0.02, respectively). CONCLUSION: The patients with high grade tumors and positive surgical margins represent a particular group with high risk of local recurrence even with radiotherapy.

Low-grade central osteosarcoma: a difficult condition to diagnose.

Low-grade central osteosarcoma (LGCO) is a rare variant of osteosarcoma which is difficult to diagnose. If not treated appropriately, the tumour can recur with higher-grade disease. We reviewed our experience of this condition to try and identify factors that could improve both diagnosis and outcome. 18 patients out of 1540 osteosarcoma cases (over 25 years) had LGCO (1.2%). Only 11 patients (61%) were direct primary referrals. Almost 40% (7 of 18) cases were referred after treatment elsewhere when the diagnosis had not been made initially and all presented with local recurrence. Of the 11 who presented primarily, the first biopsy was diagnostic in only 6 (55%) cases. Of the remaining cases, up to three separate biopsies were required before a definitive diagnosis was made. Overall survivorship at 5 years was 90%. 17 patients were treated with limb salvage procedures, and one patient had an amputation. The diagnosis of LGCO remains challenging due to the relatively nonspecific radiological and histological findings. Since treatment of LGCO is so different to a benign lesion, accurate diagnosis is essential. Any difficult or nondiagnostic biopsies of solitary bone lesions should be referred to specialist tumour units for a second opinion.

Biological reconstruction after excision, irradiation and reimplantation of diaphyseal tibial tumours using an ipsilateral vascularised fibular graft.

The purpose of this study was to assess the outcome of 15 patients (mean age 13.6 years (7 to 25)) with a primary sarcoma of the tibial diaphysis who had undergone excision of the affected segment that was then irradiated (90 Gy) and reimplanted with an ipsilateral vascularised fibular graft within it. The mean follow-up was 57 months (22 to 99). The mean time to full weight-bearing was 23 weeks (9 to 57) and to complete radiological union 42.1 weeks (33 to 55). Of the 15 patients, seven required a further operation, four to obtain skin cover. The mean Musculoskeletal Society Tumor Society functional score at final follow-up was 27 out of 30 once union was complete. The functional results were comparable with those of allograft reconstruction and had a similar rate of complication. We believe this to be a satisfactory method of biological reconstruction of the tibial diaphysis in selected patients.

Primary leiomyosarcoma of bone: analysis of prognosis.

Leiomyosarcoma of bone is just one of the variants of spindle cell sarcoma of bone characterised by the expression of desmin and other markers indicating a significant element of smooth muscle in the tumour, without osteoid production we have investigated the management and outcome of this rare type of primary malignant bone tumour. Method. Retrospective review of data stored on a prospective database. Results. In a database of 3364 patients with primary malignant bone sarcomas, 31 patients were identified with a primary leiomyosarcoma of bone. There were 12 males and 19 females with a mean age of 46 and tumour size of 8 cm. The most common site was the distal femur followed by the proximal tibia. Treatment was with chemotherapy and surgical resection. Seven of the patients had metastases at diagnosis. Surgery was carried out in 28 patients, 8 having amputation and 20 limb salvage. Three patients developed local recurrence, but half developed metastases. All patient disease-specific survival was 57% at five years and 44% at 10 yrs but for those without metastases was 82% and 60%, respectively. The only prognostic factors were metastases at diagnosis. Conclusion. Leiomyosarcoma of bone is a very rare primary malignant bone tumour affecting a predominantly older population. Despite the high incidence of metastases, survival is better than for other bone sarcomas for those without metastases at diagnosis.

Pathological fracture of the proximal femur in osteosarcoma: need for early radical surgery?

Seventeen patients underwent treatment for a pathological fracture of the proximal femur due to osteosarcoma. Their age range was from 9 to 84 (mean age 42) with nine patients under the age of 40 and eight above the age of 40. Twelve patients had a fracture at diagnosis and five developed a fracture after the diagnosis. Seven patients had metastatic disease at diagnosis. Five patients were referred after internal fixation of the fracture prior to diagnosis. Chemotherapy was used when appropriate and eight patients then underwent limb salvage surgery, six had an amputation, and three had palliative treatment. The estimated five-year survival was 14%. These results are significantly worse than expected, and it proved impossible to identify any group who fared well. The high incidence of metastases both at diagnosis and subsequently suggests this group of patients are at very high risk. Review of multicentre data may suggest an optimum treatment for this patient group.

Early results of a non-invasive extendible prosthesis for limb-salvage surgery in children with bone tumours.

We reviewed our initial seven-year experience with a non-invasive extendible prosthesis in 34 children with primary bone tumours. The distal femur was replaced in 25 cases, total femur in five, proximal femur in one and proximal tibia in three. The mean follow-up was 44 months (15 to 86) and 27 patients (79%) remain alive. The prostheses were lengthened by an electromagnetic induction mechanism in an outpatient setting and a mean extension of 32 mm (4 to 80) was achieved without anaesthesia. There were lengthening complications in two children: failed lengthening in one and the formation of scar tissue in the other. Deep infection developed in six patients (18%) and local recurrence in three. A total of 11 patients required further surgery to the leg. Amputation was necessary in five patients (20%) and a two-stage revision in another. There were no cases of loosening, but two patients had implant breakage and required revision. The mean Musculoskeletal Tumor Society functional score was 85% (60% to 100%) at last known follow-up. These early results demonstrate that the non-invasive extendible prosthesis allows successful lengthening without surgical intervention, but the high incidence of infection is a cause for concern.