Between 1982 and 1997, twenty-six children between the age of 2 and 15 (mean age 10. 6 years) underwent proximal femoral replacement. Twenty have survived and all but three have reached skeletal maturity.

Sequential radiographs have been reviewed with particular reference to acetabular development and fixation of the prostheses. Initially a cemented acetabular component was inserted, but recently uncemented implants and unipolar femoral heads that exactly fit the acetabulum have been used.

In older children the acetabulum develops normally and the components remain well fixed. One of nine children over thirteen years with a cemented acetabulum needed revision for loosening and one suffered recurrent dislocations.

In younger children the acetabulum continues to develop at the triradiate cartilage, so a cemented acetabulum grows away from the ischiopubic bar. As the component is fixed proximally, it becomes increasingly vertical and will almost inevitably loosen. In our study six of eight children under 13 years of age with a cemented acetabulum needed revision for loosening.

Unipolar replacements in younger children tend to erode the superior acetabular margin. Femoral head cover is difficult to maintain, and of four unipolar implants in children under thirteen, two required acetabular augmentation.

Cemented cups may be unsuitable for children under thirteen years but our results are not statistically significant. In this age group, unipolar implants may be more appropriate but they have serious potential complications. In children over thirteen, cemented implants survive longer. The number of uncemented implants in our study is too small to comment on long-term survival.

34 two-stage revision procedures were carried out between 1989 and 1998 for controlling deep infection following resection of bone tumours and reconstruction with endoprostheses. In 4 cases the procedure failed with early recurrent infection. In six others infection reappeared after further operative procedures. Six of these ten patients required amputation. The success of the procedure in controlling infection was 75% at 5 years. Two stage revision procedures have proved effective in controlling infection in massive endoprostheses but the risk of re-infection appears to be much greater in patients requiring further surgery for any cause.

Although pathological fractures in the aged are usually due to metastasis, solitary lesions with undetected primary should be treated with caution. Assumption of such lesions as metastatic and their subsequent internal fixation could lead to completely inappropriate treatment if the lesion turns out to be a primary sarcoma of bone.

Referrals to our bone tumour service over a four year period were analysed. There were 62 pathological fractures of which 11(17. 8%) were primary sarcomas that were treated as a metastasis. The limb salvage was compromised and survival rates poor in these group.

Although it is believed that primary sarcomas are rare in the aged, our database confirms that 14% of primary sarcomas affect this age group. The survival figures of primary sarcomas in the aged (> 60 years) treated at our centre was a mean of 43 months with a 5-year survival of 22%. The presence of a pathological fracture did not significantly alter the long-term survival of these patients. On the other hand, metastasis had a poor survival with a mean of 19 months and a 5-year survival of 4% showing a significant difference. In addition, these patients underwent major inappropriate surgeries, which rendered limb-salvage difficult, worsened the morbidity and caused mental distress to patients.

Any pathological fracture in the aged presenting as a solitary osseous lesion with an undetected primary or even remote primary should be treated with caution. Their diagnosis needs to be established by biopsy whatever the age of the patient before any form of internal fixation is undertaken. The temptation to carry out biopsy and internal fixation at the same sitting or even a prophylactic fixation should be avoided when the diagnosis is not clear. Standard principles of musculoskeletal oncology need to be followed.

Local recurrence (LR) following treatment of a sarcoma is generally accepted to be a poor prognostic sign and an indicator both of inadequate local control as well as of the failure of adjuvant treatment.

Of 2589 patients with non metastatic Ewings, osteo-sarcoma, chondrosarcoma or a soft tissue sarcoma, 316 have developed LR at some stage following initial treatment of their tumour. 120 were already known to have metastases elsewhere when they developed LR or were found to have them at time of restaging but 196 developed LR as the first sign of relapse.

The mean time to development of LR was 24 months and 72% had arisen within the first two years. Overall survival following LR was 25% at 5 years and 20% at 10 yrs. In patients with metastases at the time of LR or who were found to have them at the time of restaging the median survival was 6 months with only 12% being alive at 2 years. In those with LR as first sign of relapse median survival was 3 years with 30% long term survivors. Patients with low grade tumours had a better outcome than those with high grade – 50% being cured by further surgery. Of the high grade tumours without metastases at time of diagnosis relapsed Ewing’s had the worst prognosis with median survival of 8 months compared with 22 months for osteosarcoma, 36 months for STS and 36 months for chondrosarcoma, despite which overall survival was 16% for both Ewing’s and osteo-sarcoma patients but was 30% for chondrosarcoma and STS.

LR following sarcoma surgery is due to a combination of aggressive disease with inadequate surgery and ineffective adjuvant treatment. In isolated LR aggressive further treatment is justified with an outcome similar to that of metastatic disease.

We studied 153 patients with non-metastatic chondrosarcoma of bone to determine the risk factors for survival and local tumour control. The minimum follow-up was for five years; 52 patients had axial and 101 appendicular tumours. Surgical treatment was by amputation in 27 and limb-preserving surgery in 126.

The cumulative rate of survival of all patients, at 10 and 15 years, was 70% and 63%, respectively; 40 patients developed a local recurrence between 3 and 87 months after surgery and 49 developed metastases. Local recurrence was associated with poor survival in patients with concomitant metastases but not in those without.

On multivariate analysis independent risk factors for rates of survival include extracompartmental spread, development of local recurrence and high histological grade. Independent risk factors for local recurrence include inadequate surgical margins and tumour size greater than 10 cm. Location within the body, the type of surgery and the duration of symptoms are of no prognostic significance. Surgical excision with an oncologically wide margin provides the best prospect both for cure and local control in these patients.

Limb salvage is now customary in the treatment of primary bone tumours. The proximal tibia is a frequent site for these neoplasms but reconstruction, especially in children, is a formidable challenge. We reviewed 20 children with extendible replacements of the proximal tibia, all with a minimum follow-up of five years. Five died from their disease and, of the remaining 15, four had above-knee amputations for complications. Infection occurred in seven patients; in five it was related to the lengthening procedure. Aseptic loosening is inevitable in the younger children and only two have avoided a revision, amputation or other major complication; both were aged 12 years at the time of the initial surgery. Despite this, 11 children are alive with a functioning leg and a mean Musculoskeletal Tumour Society functional score of 83%. The lengthening mechanisms used in our series required extensive open operations. We are now using a simpler, minimally invasive, technique which we hope will decrease the incidence of complications. At present, the use of extendible prostheses of the proximal tibia remains an experimental procedure.

We carried out excision of a solitary bony metastasis from renal-cell carcinoma in 25 patients in the hope that this would produce a prolonged disease-free interval. Two patients had excisions only, five had amputations and 18 had excision and endoprosthetic replacement. The one-, three- and five-year cumulative survival rates were 88%, 54% and 13%, respectively.

There were three complications. One patient developed a local recurrence and three had problems related to the endoprosthesis.

We recommend radical excision of a solitary bony metastasis from renal-cell carcinoma to achieve local control of the tumour for the remainder of the patient’s life.

Dedifferentiated chondrosarcoma is a rare, highly malignant variant of chondrosarcoma in which a high-grade spindle-cell sarcoma coexists with a lower-grade chondroid tumour. We have reviewed our experience with this neoplasm in 22 patients, all of whom were treated using modern oncological principles of planned resection and chemotherapy. Despite this the median survival was under nine months and only 18% were alive at five years. Those patients who received chemotherapy, and in whom wide margins of excision were achieved at operation, did best. It is essential to have an accurate preoperative diagnosis in order to plan treatment which may offer a better prospect of cure.

Over a 25-year period we have treated 36 patients with osteosarcoma of the pelvis. Of the tumours, 24 (67%) were primary osteosarcomas and 12 (33%) arose either after irradiation or in association with Paget’s disease. Six patients had a hindquarter amputation and 12 were treated by a limb-salvage procedure with intrapelvic excision.

The five-year survival rate of all the patients with pelvic osteosarcoma was 18%, while for 17 treated by chemotherapy and surgery it was 41%. The prognosis for patients presenting with metastases or with secondary osteosarcoma was appalling and none survived after 29 months. No patient over the age of 50 years when seen initially survived for a year. Youth and a good response to chemotherapy along with complete surgical excision offer the best chance of cure.

We have performed endoprosthetic replacement after resection of tumours of the proximal tibia on 151 patients over a period of 20 years. During this period limb-salvage surgery was achieved in 88% of patients with tumours of the proximal tibia. Both the implant and the operative technique have been gradually modified in order to reduce complications. An initial rate of infection of 36% has been reduced to 12% by the use of a flap of the medial gastrocnemius, to which the divided patellar tendon is attached. Loosening and breakage of the implant have been further causes of failure. We found that the probability of further surgical procedures being required was 70% at ten years and the risk of amputation, 25%. The development of a new rotating hinge endoprosthesis may lower the incidence of mechanical problems.

Limb salvage for tumours of the proximal tibia is fraught with complications, but the good functional outcome in successful cases justifies its continued use.

We carried out extensible endoprosthetic replacement of the proximal or total humerus in 18 children aged between six and 12 years, after resection of primary bone tumours mainly for osteosarcoma and Ewing’s sarcoma. In 11 patients we performed 44 lengthening procedures, with an average of two per child annually and a mean total extension of 29.9 mm per patient. We were able to achieve lengthening of the operated limb with few complications and a mean functional rating of 79.3% according to the Enneking system. Progressive lengthening of these prostheses does not adversely affect the overall function of the arm, and superior subluxation of the head of the prosthesis has not been a problem.

We studied the CT and MR scans, and the histology of 50 patients with primary Ewing’s sarcoma of bone to determine the association between the change in tumour volume and necrosis after chemotherapy, and to ascertain their influence on prognosis. The mean age of the patients was 17 years. The limbs were involved in 40 and the axial bones in ten. The volume of the tumour at diagnosis varied from 31 to 1790 ml.

There was a significant relationship between necrosis and the measured change in volume of the tumour after chemotherapy. Progression of the tumour despite chemotherapy was seen only in patients with necrosis of grades 4 to 6. Necrosis significantly influenced survival (p < 0.05), but the effect of change in volume was less significant.

Change in volume of the tumour is a good predictor of necrosis induced by chemotherapy. Necrosis is a strong prognostic factor in Ewing’s sarcoma.

We reviewed 20 patients after forequarter amputation performed for high-grade malignant tumours of the shoulder girdle (Enneking grades IIB to III). The operations were classified as palliative or curative according to the resection margins and the presence of disseminated disease at the time of the surgery.

There were five palliative and 15 curative procedures. Two patients died from unrelated causes, septicaemia and suicide. Eight died in the first two years, four of whom had had a palliative operation. Four died between two and five years after surgery, one after a palliative operation. Five patients are alive, at a mean of 89.4 months after surgery, four of whom are free from disease. The median survival after a palliative amputation was 20.6 months. Our overall five-year survival (palliative and curative cases) was 21.2%, for curative cases it was 30.2%. None of the patients use an artificial prosthesis.

Despite the disfigurement which results from this operation, it still has a useful role to play in the management of high-grade malignant tumours of the upper limb.

We report our results in 24 children with malignant primary bone tumours of the distal femur treated with a Stanmore extendible endoprosthesis (SEER). This consists of a femoral component that can be lengthened, a constrained knee and an uncemented sliding tibial component which crosses the proximal tibial physeal plate perpendicularly.

The average age of the patients at diagnosis was ten years and the mean follow-up was 4.7 years (2.5 to 7.9). The mean growth of the affected tibia was 76% (18 to 136) and of the fibula 83% (15 to 750) of the growth of the unaffected limb.

Measurement of growth arrest lines showed that the mean growth of the proximal tibial physis on the affected side was 69% (43 to 100) of that of the normal side. The great variability in the growth of the physis cannot yet be explained.

We treated 35 patients with primary malignant tumours of the periacetabular area by resection and prosthetic reconstruction of the defect. At a mean follow-up of 84 months, 15 patients (43%) were free from disease. The most common complications were deep infection (26%), local recurrence (24%) and recurrent dislocation of the hip (17%). The surviving patients achieved an average of 70% of their premorbid function.

This method of reconstruction has a high morbidity and should be performed only at specialist centres, but the functional and oncological outcomes are satisfactory.

The use of endoprostheses for limb salvage in primary bone tumours is highly specialised. Studies have shown no significant difference in survival, function or quality of life between patients with limb salvage and those with amputation.

We have derived a formula for calculating the ongoing costs of limb salvage with an endoprosthesis which is based on actual costs and uses historical data to show the likelihood of further surgery or revision. Comparative data for amputation are also shown. Using current prices, the cost-effectiveness of surgery with an endoprosthesis is clearly demonstrated.

We reviewed the surgical treatment and oncological results of 40 patients with pathological fractures from localised osteosarcoma of the long bones to determine the outcome of limb salvage in their management. All had had adjuvant chemotherapy. There were 26 males and 14 females with a median age at diagnosis of 18 years (2 to 46) and a median follow-up of 55 months (8 to 175).

We performed limb salvage in 27 patients and amputation in 13. The margins of resection were radical in five patients, wide in 26, marginal in six, wide but contaminated in two and intralesional in one. Local recurrence developed in 19% of those treated by limb salvage and in none of those who had an amputation. The cumulative five-year survival of all the patients was 57% and in those treated by limb salvage or amputation it was 64% and 47%, respectively (p > 0.05).

Limb-sparing surgery with adequate margins of excision can be achieved in many patients with pathological fractures from primary osteosarcoma without compromising survival, but the risk of local recurrence is significant.

Improvement in the life expectancy of patients with primary bone tumours has led to increased emphasis on limb salvage and preservation of function.

Between 1979 and 1994 we used custom-made endoprostheses in 18 patients to reconstruct diaphyseal defects after excision of primary bone tumours. The mean age at operation was 26 years (9 to 64) and the median follow-up 65 months (6 to 188).

Fifteen patients have survived and are free from local or metastatic disease. Local recurrence developed in one patient. Using the modified Enneking functional scoring system, 77% of the patients achieved 80% or more of their premorbid functional capability. Mechanical loosening, limb shortening and secondary osteoarthritis were the main complications. There were no infections.

We conclude that diaphyseal endoprostheses offer a good clinical and functional outcome in the lower limb.