We reviewed nine patients at a mean period of 11 years (6 to 16) after curettage and cementing of a giant-cell tumour around the knee to determine if there were any long-term adverse effects on the cartilage. Plain radiography, MRI, delayed gadolinium-enhanced MRI of the cartilage and measurement of the serum level of cartilage oligomeric matrix protein were carried out. The functional outcome was evaluated using the Lysholm knee score.

Each patient was physically active and had returned to their previous occupation. Most participated in recreational sports or exercise.

The mean Lysholm knee score was 92 (83 to 100). Only one patient was found to have cartilage damage adjacent to the cement. This patient had a history of intra-articular fracture and local recurrence, leading to degenerative changes.

Interpretation of the data obtained from delayed gadolinium-enhanced MRI of the cartilage was difficult, with variation in the T1 values which did not correlate with the clinical or radiological findings. We did not find it helpful in the early diagnosis of degeneration of cartilage. We also found no obvious correlation between the serum cartilage oligomeric matrix protein level and the radiological and MR findings, function, time after surgery and the age of the patient.

In summary, we found no evidence that the long-term presence of cement close to the knee joint was associated with the development of degenerative osteoarthritis.

Between 1996 and 2003, 16 patients (nine female, seven male) were treated for a primary bone sarcoma of the femur by wide local excision of the tumour, extracorporeal irradiation and re-implantation. An additional vascularised fibular graft was used in 13 patients (81%). All patients were free from disease when reviewed at a minimum of two years postoperatively (mean 49.7 months (24 to 96).

There were no cases of infection. Primary union was achieved after a median of nine months (interquartile range 7 to 11). Five host-donor junctions (16%) united only after a second procedure. Primary union recurred faster at metaphyseal junctions (94% (15) at a median of 7.5 months (interquartile range 4 to 12)) than at diaphyseal junctions (75% (12) at a median of 11.1 months (interquartile range 5 to 18)).

Post-operatively, the median Musculoskeletal Tumour Society score was 85% (interquartile range 75 to 96) and the median Toronto Extremity Salvage score 94% (interquartile range 82 to 99). The Mankin score gave a good or excellent result in 14 patients (88%).

The range of movement of the knee was significantly worse when the extracorporeally irradiated autografts were fixed by plates rather than by nails (p = 0.035).

A total of 16 (62%) of the junctions of the vascularised fibular grafts underwent hypertrophy, indicating union and loading.

Extracorporeal irradiation autografting with supplementary vascularised fibular grafting is a promising biological alternative for intercalary reconstruction after wide resection of malignant bone tumours of the femur.

We evaluated 31 patients who were treated with a non-vascularised fibular graft after resection of primary musculoskeletal tumours, with a median follow-up of 5.6 years (3 to 26.7 years). Primary union was achieved in 89% (41 of 46) of the grafts in a median period of 24 weeks. All 25 grafts in 18 patients without additional chemotheraphy and/or radiotherapy achieved primary union, compared with 16 of the 21 grafts (76%; 13 patients) with additional therapy (p = 0.017). Radiographs showed an increase in diameter in 70% (59) of the grafts. There were seven fatigue fractures in six patients, but only two needed treatment.

Non-vascularised fibular transfer is a simpler, less expensive and a shorter procedure than the use of vascularised grafts and allows remodelling of the fibula at the donor site. It is a biological reconstruction with good long-term results, and a relatively low donor site complication rate of 16%.

Open surgery is rarely justified for the initial treatment of a unicameral bone cyst, but there is some debate concerning the relative effectiveness of closed methods. This study compared the results of steroid injection with those of autologous bone marrow grafting for the treatment of unicameral bone cysts. Between 1990 and 2001, 30 patients were treated by steroid injection and 28 by grafting with autologous bone marrow. The overall success rates were 86.7% and 92.0%, respectively (p > 0.05). The success rate after the initial procedure was 23.3% in the steroid group and 52.0% in those receiving autologous bone marrow (p < 0.05), and the respective cumulative success rates after second injections were 63.3% and 80.0% (p > 0.05). The mean number of procedures required was 2.19 (1 to 5) and 1.57 (1 to 3) (p < 0.05), the mean interval to healing was 12.5 months (4 to 32) and 14.3 months (7 to 36) (p > 0.05), and the rate of recurrence after the initial procedure was 41.7% and 13.3% in the steroid and in the autologous bone marrow groups, respectively (p < 0.05).

Although the overall rates of success of both methods were similar, the steroid group had higher recurrence after a single procedure and required more injections to achieve healing.

Between December 1995 and March 2003, 38 adult patients with intermediate or high-grade liposarcoma in a limb were treated by limb-sparing surgery and post-operative radiotherapy. The ten-year local recurrence-free survival was 83%, the ten-year metastasis-free survival 61%, the ten-year disease-free survival 51% and the ten-year overall survival 67%. Analysis of failure and success showed no association with the age of the patients, gender, the location of the primary tumour, the type of liposarcoma and the quality of resection.

Our results indicate that liposarcoma may recur even ten years after the end of definitive therapy and may spread to unexpected sites as for soft-tissue sarcoma.

We report the results of limb salvage for non-metastatic osteosarcoma of the distal tibia using resection arthrodesis, autogenous fibular graft and fixation by an Ilizarov external fixator.

In six patients with primary osteosarcoma of the distal tibia who refused amputation, treatment with wide en bloc resection and tibiotalar arthrodesis was undertaken. The defect was reconstructed using non-vascularised free autogenous fibular strut graft in three patients and a vascularised pedicular fibular graft in three, all supplemented with iliac cancellous graft at the graft-host junction. An Ilizarov external fixator was used for stabilisation of the reconstruction.

In five patients sound fusion occurred at a mean of 13.2 months (8 to 20) with no evidence of local recurrence or deep infection at final follow-up. The mean post-operative functional score was 70% (63% to 73%) according to the Musculoskeletal Tumour Society scoring system. All five patients showed graft hypertrophy.

Union of the graft was faster in cases reconstructed by vascularised fibular grafts. One patient who had a poor response to pre-operative chemotherapy developed local tumour recurrence at one year post-operatively and required subsequent amputation.

We have investigated the significance of the method of treatment on the oncological and functional outcomes and on the complications in 184 patients with soft-tissue sarcomas of the adductor compartment managed at three international centres. The overall survival at five years was 65% and was related to the grade at diagnosis and the size of the tumour. There was no difference in overall survival between the three centres. There was, however, a significant difference in local control with a rate of 28% in Centre 1 compared with 10% in Centre 2 and 5% in Centre 3.

The overall mean functional score using the Toronto Extremity Salvage Score in 70 patients was 77% but was significantly worse in patients with wound complications or high-grade tumours. The scores were not affected by the timing of radiotherapy or the use of muscle flaps.

This large series of soft-tissue sarcomas of the adductor compartment has shown that factors influencing survival do not vary across the international boundaries studied, but that methods of treatment affect complications, local recurrence and function.

Custom-made intercalary endoprostheses may be used for the reconstruction of diaphyseal defects following the resection of bone tumours. The aim of this study was to determine the survival of intercalary endoprostheses with a lap joint design, and to evaluate the clinical results, complications and functional outcome. We retrospectively reviewed six consecutive patients, three of whom underwent limb salvage with intercalary endoprostheses of the tibia, two of the femur, and one of the humerus. Their mean age was 42 years (28 to 64). The mean follow-up was 21.6 months (9 to 58). The humeral prosthesis required revision at 14 months owing to aseptic loosening. There were no implant-related failures. Musculoskeletal Tumour Society functional outcome scores indicated that patients achieved 90% of premorbid function.

Custom intercalary endoprostheses result in reconstructions comparable with, if not better than, those of allografts. Using this design of implant reduces the incidence of early complications and difficulties experienced with previous versions.

We used a knee-sparing distal femoral endoprosthesis in young patients with malignant bone tumours of the distal femur in whom it was possible to resect the tumour and to preserve the distal femoral condyles. The proximal shaft of the endoprosthesis had a coated hydroxyapatite collar, while the distal end had hydroxyapatite-coated extracortical plates to secure it to the small residual femoral condylar fragment. We reviewed the preliminary results of this endoprosthesis in eight patients with primary bone tumours of the distal femur. Their mean age at surgery was 17.years (14 to 21). The mean follow-up was 24 months (20 to 31). At final follow-up the mean flexion at the knee was 102° (20° to 120°) and the mean Musculoskeletal Tumour Society score was 80% (57% to 96.7%).

There was excellent osteointegration at the prosthesis-proximal bone interface with formation of new bone around the hydroxyapatite collar. The prosthesis allowed preservation of the knee and achieved a good functional result. Formation of new bone and remodelling at the interface make the implant more secure. Further follow-up is required to determine the long-term structural integrity of the prosthesis.

The most appropriate protocol for the biopsy of musculoskeletal tumours is controversial, with some authors advocating CT-guided core biopsy. At our hospital the initial biopsies of most musculoskeletal tumours has been by operative core biopsy with evaluation by frozen section which determines whether diagnostic tissue has been obtained and, if possible, gives the definitive diagnosis. In order to determine the accuracy and cost-effectiveness of this protocol we have undertaken a retrospective audit of biopsies of musculoskeletal tumours performed over a period of two years.

A total of 104 patients had biopsies according to this regime. All gave the diagnosis apart from one minor error which did not alter the management of the patient. There was no requirement for re-biopsy. This protocol was more labour-intensive and 38% more costly than CT-guided core biopsy (AU$1804 vs AU$1308). However, the accuracy and avoidance of the anxiety associated with repeat biopsy outweighed these disadvantages.

Aneurysmal bone cyst is a rare tumour-like lesion which develops during growth. Our aim was to determine the efficacy of the administration of percutaneous intralesional 3% polidocanol (hydroxypolyaethoxydodecan) as sclerotherapy.

Between July 1997 and December 2004 we treated 72 patients (46 males, 26 females) with a histologically-proven diagnosis of aneurysmal bone cyst, at various skeletal sites using this method. The sclerotherapy was performed under fluoroscopic guidance and general anaesthesia or sedation and local anaesthesia. The mean follow-up period was 34 months (26.5 to 80). The patients were evaluated using the Enneking system for functional assessment and all the lesions were radiologically quantified into four grades.

The mean age of patients was 15.6 years (3 to 38) and the mean number of injections was three (1 to 5). Ten patients were cured by a single injection. The mean reduction in size of the lesion (radiological healing) was found to be 76.6% (61.9% to 93.2%) with a mean clinical response of 84.5% (73.4% to 100%). Recurrence was seen in two patients (2.8%) within two years of treatment and both were treated successfully by further sclerotherapy.

Percutaneous sclerotherapy with polidocanol is a safe alternative to conventional surgery for the treatment of an aneurysmal bone cyst. It can be used at surgically-inaccessible sites and treatment can be performed on an out-patient basis.

Between 1986 and 2002, 42 patients with synchronous multifocal osteosarcoma were treated with two different protocols of neoadjuvant chemotherapy. When feasible, the primary and secondary tumours were excised as a combined procedure.

After initial chemotherapy 26 patients were excluded from simultaneous excision of all their secondary bone lesions as their disease was too advanced. In 12 patients only isolated excision of the primary lesion was possible. For 16 patients simultaneous operations were conducted to excise the primary and secondary lesions. This involved two supplementary sites in 15 patients and four additional sites in one patient. Of these, 15 attained remission but 12 relapsed and died (11 within two years). Three patients remained disease-free at five, six and 17 years. The histological response to pre-operative chemotherapy of the primary and secondary lesions was concordant in 13 of the 16 patients who underwent simultaneous operations at more than one site.

The prognosis for synchronous multifocal osteosarcoma remains poor despite combined chemotherapy and surgery. The homogeneous histological responses in a large proportion of the primary and secondary lesions implies that synchronous multifocal osteosarcoma tumours are not multicentric in origin, but probably represent bone-to-bone metastases from a single tumour.

We reviewed retrospectively the results in 211 consecutive patients who had undergone limb salvage for bone neoplasia with endoprosthetic reconstruction of the proximal femur (96), distal femur (78), proximal tibia (30) and total femur (7). Their mean age was 50 years (11 to 86) and the mean follow-up period was 37.3 months (1 to 204). A total of 35 (16.6%) prostheses failed. Overall, implant survival was 78% (95% confidence interval (CI) 0.29 to 0.54) at five years, 60% (95% CI 0.93 to 2.35) at ten years and 60% (95% CI 1.27 to 3.88) at 15 years. Survivorship of the limb was 97.6% (95% CI 1.73 to 3.35) at ten years. The gender, age, diagnosis and location of the tumour were not prognostic variables for failure. Modular endoprosthetic replacement in the lower limb is a durable long-term reconstructive option, with the implants generally outlasting the patient.

We report our early experience with the use of a non-invasive distal femoral expandable endoprosthesis in seven skeletally immature patients with osteosarcoma of the distal femur. The patients had a mean age of 12.1 years (9 to 15) at the time of surgery. The prosthesis was lengthened at appropriate intervals in outpatient clinics, without anaesthesia, using the principle of electromagnetic induction. The patients were functionally evaluated using the Musculoskeletal Tumour Society scoring system. The mean follow-up was 20.2 months (14 to 30). The prostheses were lengthened by a mean of 25 mm (4.25 to 55) and maintained a mean knee flexion of 110° (100° to 120°). The mean Musculoskeletal Tumour Society score was 68% (11 to 29). Complications developed in two patients; one developed a flexion deformity of 25° at the knee joint, which was subsequently overcome and one died of disseminated disease. The early results from patients treated with this device have been encouraging. The implant avoids multiple surgical procedures, general anaesthesia and assists in maintaining leg-length equality.

We retrospectively studied local recurrence of giant cell tumour in long bones following treatment with curettage and cementing in 137 patients. The median follow-up time was 60 months (3 to 166). A total of 19 patients (14%) had at least one local recurrence, the first was diagnosed at a median of 17 months (3 to 29) after treatment of the primary tumour. There were 13 patients with a total of 15 local recurrences who were successfully treated by further curettage and cementing. Two patients with a second local recurrence were consequently treated twice. At the last follow-up, at a median of 53 months (3 to 128) after the most recent operation, all patients were free from disease and had good function.

We concluded that local recurrence of giant cell tumour after curettage and cementing in long bones can generally be successfully treated with further curettage and cementing, with only a minor risk of increased morbidity. This suggests that more extensive surgery for the primary tumour in an attempt to obtain wide margins is not the method of choice, since it leaves the patient with higher morbidity with no significant gain with respect to cure of the disease.

The outcome of tibial allograft reconstruction after resection of a tumour is inconsistent and has a high rate of failure. There are few reports on the use of tibial allografts in children with open growth plates. We performed 21 allograft reconstructions (16 osteoarticular, five intercalary) in 19 consecutive patients between seven and 17 years of age. Two had Ewing’s sarcoma, one an adamantinoma and 16 osteosarcoma, one with multifocal disease.

Five patients have died; the other 14 were free from disease at the time of follow-up. Six surviving patients (eight allograft reconstructions) continue to have good or excellent function at a mean of 59 months (14 to 132). One patient has poor function at 31 months. The other seven patients have a good or excellent function after additional procedures including exchange of the allograft and resurfacing or revision to an endoprosthesis at a mean of 101 months (43 to 198). The additional operations were performed at a mean of 47 months (20 to 84) after the first reconstruction.

With the use of allograft reconstruction in growing children, joints and growth plates may be preserved, at least partially. Although our results remain inconsistent, tibial allograft reconstruction in selected patients may restore complete and durable function of the limb.

A retrospective analysis was performed of eight patients with an open triradiate cartilage, who underwent resection for osteosarcoma and reconstruction of the proximal femur with a hemiarthroplasty, in order to identify changes of acetabular development. An analysis of the centre-edge angle, teardrop-to-medial prosthesis distance, superior joint space, teardrop-to-superior prosthesis distance, degree of lateral translation, and arthritic changes, was performed on serial radiographs. The median age at the time of the initial surgery was 11 years (5 to 14).

All patients developed progressive superior and lateral migration of the prosthetic femoral head. Following hemiarthroplasty in the immature acetabulum, the normal deepening and enlargement of the acetabulum is arrested. The degree of superior and lateral migration of the prosthetic head depends on the age at diagnosis and the length of follow-up.

We report positive and negative factors associated with the most commonly-used methods of reconstruction after pathological fracture of the proximal femur. The study was based on 142 patients treated surgically for 146 metastatic lesions between 1996 and 2003. The local rate of failure was 10.3% (15 of 146). Of 37 operations involving osteosynthetic devices, six failed (16.2%) compared with nine (8.3%) in 109 operations involving endoprostheses. Of nine cases of prosthetic failure, four were due to periprosthetic fractures and three to recurrent dislocation. In the osteosynthesis group, three (13.6%) of 22 reconstruction nails failed. The two-year risk of re-operation after any type of osteosynthesis was 0.35 compared with 0.18 after any type of endoprosthetic reconstruction (p = 0.07). Endoprosthetic reconstructions are preferable to the use of reconstruction nails and other osteosynthetic devices for the treatment of metastatic lesions in the proximal third of the femur.

We reviewed 124 patients with a conventional pelvic chondrosarcoma who had been treated over a period of 20 years. We recorded the type of tumour (central or peripheral), type of operation (limb salvage surgery or hemipelvectomy), the grade of tumour, local recurrence and/or metastases, in order to identify the factors which might influence survival.

More satisfactory surgical margins were achieved for central tumours or in those patients treated by hemipelvectomy. However, grade 1 tumours, whatever the course, did not develope metastases or cause death, while grade 3 tumours had the worst outcome and prognosis.

Central, high-grade tumours require aggressive surgical treatment in order to achieve adequate surgical margins, particularly in those lesions located close to the sacroiliac joint. By contrast, grade 1 peripheral chondrosarcomas may be treated with contaminated margins in order to reduce operative morbidity, but without reducing survival.

We undertook this retrospective study to determine the rate of recurrence and functional outcome after intralesional curettage for chondroblastoma of bone. The factors associated with aggressive behaviour of the tumour were also analysed. We reviewed 53 patients with histologically-proven chondroblastoma who were treated by intralesional curettage in our unit between 1974 and 2000. They were followed up for at least two years to a maximum of 27 years.

Seven (13.2%) had a histologically-proven local recurrence. Three underwent a second intralesional curettage and had no further recurrence. Two had endoprosthetic replacement of the proximal humerus and two underwent below-knee amputation after aggressive local recurrence. One patient had the rare malignant metastatic chondroblastoma and eventually died. The mean Musculoskeletal Tumour Society functional score of the survivors was 94.2%.

We conclude that meticulous intralesional curettage alone can achieve low rates of local recurrence and excellent long-term function.

We treated 50 patients with bony malignancy by en-bloc resection, extracorporeal irradiation with 50 Gy and re-implantation of the bone segment.

The mean survivor follow-up was 38 months (12 to 92) when 42 patients were alive and without disease. There were four recurrences. The functional results were good according to the Mankin score (17 excellent, 13 good, nine fair, three failures), the Musculoskeletal Tumour Society score (mean 77) and the Toronto Extremity Salvage score (mean 81). There was solid union, but bone resorption was seen in some cases. The dose of radiation was lethal to all cells and produced a dead autograft of perfect fit.

Extracorporeal irradiation is a useful technique for limb salvage when there is reasonable residual bone stock. It allows effective re-attachment of tendons and produces a lasting biological reconstruction. There should be no risk of local recurrence or of radiotherapy-induced malignancy in the replanted bone.

We reviewed 29 patients who had undergone intercalary resection for malignant tumours. Of these, 14 had received segmental allograft reconstruction and 15 extracorporeally-irradiated autograft.

At a mean follow-up of 71 months (24 to 132), 20 were free from disease, five had died and four were alive with pulmonary metastases. Two patients, one with an allograft and one with an irradiated autograft, had a local recurrence. Reconstruction with extracorporeally-irradiated autograft has a significantly lower rate of nonunion (7% vs 43%, p = 0.031) but an insignificantly higher rate of fracture (20% vs 14%, p = 0.535) than that with segmental allograft. Using the Enneking functional evaluation system, the mean postoperative score for the patients without local recurrence was 87% (80% to 96%) and was similar in both groups.

Extracorporeally-irradiated autograft could be an acceptable alternative for reconstruction after intercalary resection, especially in countries where it is difficult to obtain allografts.

Between 1992 and 1999, we treated 350 patients with skeletal metastases. A multivariable analysis of the patients was conducted using the Cox proportional hazards model. We identified five significant prognostic factors for survival, namely, the site of the primary lesion, the performance status (Eastern Cooperative Oncology Group status 3 or 4), the presence of visceral or cerebral metastases, any previous chemotherapy, and multiple skeletal metastases. The score for each significant factor was derived from the corresponding estimated regression coefficients (natural logarithm of the hazard ratio). The prognostic score was calculated by adding all the scores for individual factors.

The rate of survival was 31% at six months and 11% at one year for the patients with a prognostic score of 6 or more. By contrast, patients with a prognostic score of 2 or less had a rate of survival of 98% at six months and 89% at one year. This scoring system can be used to determine the optimal treatment for patients with pathological fractures or epidural compression.

Massive endoprostheses using a cemented intramedullary stem are widely used to allow early resumption of activity after surgery for tumours. The survival of the prosthesis varies with the anatomical site, the type of prosthesis and the mode of fixation. Revision surgery is required in many cases because of aseptic loosening. Insertion of a second cemented endoprosthesis may be difficult because of the poor quality of the remaining bone, and loosening recurs quickly.

We describe a series of 14 patients with triplate fixation in difficult revision or joint-sparing tumour surgery with a minimum follow-up of four years. The triplate design incorporated well within a remodelled cortex to achieve osseomechanical integration with all patients regaining their original level of function within five months.

Our preliminary results suggest that this technique may provide an easy, biomechanically friendly alternative to insertion of a further device with an intramedullary stem, which has a shorter lifespan in revision or joint-sparing tumour surgery. A short segment of bone remaining after resection of a tumour will not accept an intramedullary stem, but may be soundly fixed using this method.

We describe a method of reconstruction using tumour-bearing autograft treated by liquid nitrogen in 28 patients. The operative technique consisted of en bloc excision of the tumour, removal of soft tissue, curettage of the tumour, drilling and preparation for internal fixation or prosthetic replacement before incubation for 20 minutes in liquid nitrogen, thawing at room temperature for 15 minutes, thawing in distilled water for ten minutes, and internal fixation with an intramedullary nail, plate or composite use of prosthetic replacement. Bone graft or cement was used to augment bone strength when necessary.

The limb function was rated as excellent in 20 patients (71.4%), good in three (10.7%), fair in three (10.7%), and poor in two (7.1%). At the final follow-up six patients had died at a mean of 19.8 months after the operation, while 21 remained free from disease with a mean follow-up of 28.1 months (10 to 54). One patient is alive with disease. Bony union was seen at a mean of 6.7 months after the operation in 26 patients. Complications were encountered in seven patients, including three deep infections, two fractures, and two local recurrences. All were managed successfully. Our results suggest that this is a simple and effective method of biological reconstruction.

We performed a prospective genotype-phenotype study using molecular screening and clinical assessment to compare the severity of disease and the risk of sarcoma in 172 individuals (78 families) with hereditary multiple exostoses. We calculated the severity of disease including stature, number of exostoses, number of surgical procedures that were necessary, deformity and functional parameters and used molecular techniques to identify the genetic mutations in affected individuals. Each arm of the genotype-phenotype study was blind to the outcome of the other. Mutations EXT1 and EXT2 were almost equally common, and were identified in 83% of individuals. Non-parametric statistical tests were used.

There was a wide variation in the severity of disease. Children under ten years of age had fewer exostoses, consistent with the known age-related penetrance of this condition. The severity of the disease did not differ significantly with gender and was very variable within any given family. The sites of mutation affected the severity of disease with patients with EXT1 mutations having a significantly worse condition than those with EXT2 mutations in three of five parameters of severity (stature, deformity and functional parameters). A single sarcoma developed in an EXT2 mutation carrier, compared with seven in EXT1 mutation carriers. There was no evidence that sarcomas arose more commonly in families in whom the disease was more severe.

The sarcoma risk in EXT1 carriers is similar to the risk of breast cancer in an older population subjected to breast-screening, suggesting that a role for regular screening in patients with hereditary multiple exostoses is justifiable.

We report our experience with a new technique for cryosurgical ablation of bone tumours which allows accurate determination of the temperature and freezing time within a cavity of any geometrical shape.

Between 1997 and 2000, 58 patients diagnosed with 13 malignant and 45 aggressive benign bone tumours underwent argon-based cryoablation. This technique includes removal of the tumour by curettage and filling the cavity with a gel medium into which metal probes are inserted. Argon gas is delivered through the metal probes and both time and temperature are computer-controlled. After formal reconstruction, all patients were followed for more than two years. None had skin necrosis, infection, neurapraxia or thromboembolic complication. Fractures occurred in two patients (3.4%) and the tumour recurred in two patients (3.4%).

We reviewed the results of 51 patients with benign bone tumours treated by curettage and implantation of calcium hydroxyapatite ceramic (CHA). The mean follow-up was 11.4 years (10 to 15.5). Post-operative fractures occurred in two patients and three had local recurrences; three had slightly limited movement of the adjacent joint and one had mild osteoarthritis. There were no allergic or neoplastic complications. In all cases, radiographs showed that the CHA was well incorporated into the host bone.

Statistical analysis showed that absorption of the implanted CHA was greater in males (odds ratio, 6.2; 95% CI, 1.6 to 23.7) and younger patients (odds ratio, 0.6 for increase in age of 10 years; 95% CI, 0.91 to 0.99). However, the implanted CHA was not completely absorbed in any patient.

We conclude that CHA is a useful and safe bone substitute for the treatment of benign bone tumours.

A number of risk factors based upon mostly retrospective surgical data, have been formulated in order to identify impending pathological fractures of the femur from low-risk metastases. We have followed up patients taking part in a randomised trial of radiotherapy, prospectively, in order to determine if these factors were effective in predicting fractures. In 102 patients with 110 femoral lesions, 14 fractures occurred during follow-up. The risk factors studied were increasing pain, the size of the lesion, radiographic appearance, localisation, transverse/axial/circumferential involvement of the cortex and the scoring system of Mirels. Only axial cortical involvement > 30 mm (p = 0.01), and circumferential cortical involvement > 50% (p = 0.03) were predictive of fracture. Mirels’ scoring system was insufficiently specific to predict a fracture (p = 0.36). Our results indicate that most conventional risk factors overestimate the actual occurrence of pathological fractures of the femur. The risk factor of axial cortical involvement provides a simple, objective tool in order to decide which treatment is appropriate.

Giant-cell tumour of bone (GCT) is a locally benign aggressive tumour. The use of adjuvant agents, such as phenol or liquid nitrogen has been recommended to destroy the remaining tumour cells after curettage, and filling of the defect with methylmethacrylate cement has been advocated. Between 1957 and 1992 we treated 92 patients with a GCT with 50% aqueous zinc chloride solution and bone grafting. Their mean age at the time of surgery was 31 years (15 to 59) and the mean follow-up was 11 years (5 to 31).

Twelve (13%) had a local recurrence and one had a wound infection. Two developed degenerative changes around the knee. Eighty-six (93%) achieved good or excellent function. Three had moderate function, and three needed amputation. Our findings indicate that treatment with an aqueous solution of zinc chloride and reconstructive bone grafting after curettage gives good results.

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.

The management of spinal metastases is palliative and aimed at improving quality of life at an acceptable risk. This population study uses administrative databases and measures survivorship and complication rates after surgery for spinal metastases. The effects of various potential predictor variables were evaluated. We identified 987 patients with a median survival for all types of cancer of 227 days. The one and three-month mortality was 9% and 29%, respectively. Increasing age, male gender and primary lung cancer were significant risk factors for death within 30 days of surgery. A preoperative neurological deficit contributed a 19% increase in mortality and a 71% increase in the risk of postoperative wound infection. We found an overall major complication rate of 27%. This information will provide patients, families and clinicians with objective data which will help in the choice of treatment and the understanding of the surgical risk and outcome.

An increased long-term survival of patients with malignant tumours also increases the possibility of the development of skeletal metastases and pathological fractures. The management of bone metastases includes the removal of gross disease and the administration of local adjuvants. We have investigated the possibility of adding antiblastic drugs to acrylic cement.

Cylinders of acrylic cement were manufactured containing three different antiblastic drugs, methotrexate, cisplatin and doxorubicin.

We performed in vitro analysis on MCF-7 human breast cancer cells in order to evaluate the biological effect of the mixtures and surface analysis of the acrylic cement-cisplatin cylinders using energy-dispersive x-ray analysis (EDAX). All drugs were released in an active form from the cement. Each drug had a different effect on cell viability. Doxorubicin had the greatest effect on breast cancer cells. Surface analysis showed that antiblastic drugs were present in the form of granules.

These results confirm the potential of antiblastic-loaded cement as a possible adjuvant in the local treatment of bone metastases.

Further studies should be undertaken to determine whether the release of antiblastic drugs from cement is elution or if they are only released from the surface.

In this retrospective study, we analysed the clinical features of neurilemoma when it is located in muscle. Twelve patients had an intramuscular neurilemoma as shown on magnetic resonance (MR) scans and confirmed at operation. In six it was located in the upper limb, in five in the lower limb, and in one in the back. The mean age of the patients was 41 years (12 to 58). Nine complained only of a palpable mass and the other three of a mass with slight tenderness. None had neurological symptoms or signs, such as radicular pain, a positive Tinel sign, or motor weakness. There were no postoperative complications or recurrence of the tumour after a mean follow-up of two years (1 to 10).

We studied 100 patients who had undergone endoprosthetic replacement of the proximal humerus between 1976 and 1998. The outcome was assessed with regard to the survivorship of the patients, the salvaged limbs and the prostheses. Function was determined in the 47 surviving patients, of whom 30 were assessed using the Musculo-Skeletal Tumour Society (MSTS) rating scale and 38 completed the Toronto Extremity Salvage Score (TESS) questionnaire.

The median age of the patients was 34 years (10 to 80). The mean follow-up period for surviving patients was nine years (2 to 20). The mean MSTS score at follow-up was 79% and the mean TESS score was 72%. The length of bone which was resected influenced the functional outcome. Abduction of the shoulder was to 45° in most patients. The overall survival was 42% at ten years and that of the limb without amputation 93%. The survival of the prostheses using mechanical failure as the endpoint was 86.5% at 20 years.

Endoprosthetic replacement of the proximal humerus is a predictable procedure providing reasonable function of the arm with a low rate of complications at long-term follow-up.

A prospective single-cohort study was designed to include 20 patients with enchondromas but was stopped because of poor early results. Four patients with an enchondroma, three in the proximal humerus and one in the distal femur, were treated by curettage and filling of the defect with Norian SRS cement. Clinical and radiological follow-up including CT and MRI was carried out for 18 months. All three patients with lesions in the proximal humerus had severe pain and limited movement of the shoulder. The radiological and CT appearances of the cement were unchanged at follow-up. There were characteristic appearances of synovitis and periosteitis on MRI in two patients. Since the cement induces a soft-tissue reaction the bony cavity should be sealed with the curetted and burred bone after curettage and introduction of Norian cement, especially in sites where a tourniquet cannot be applied.

We studied the bone mineral density (BMD) of 48 long-term survivors of highly malignant osteosarcoma who had been treated according to the chemotherapy protocols of the German- Swiss-Austrian Co-operative Osteosarcoma Study Group which include high-dose methotrexate. The mean age of the patients was 31 ± 4.2 years and the mean follow-up 16 ± 2.2 years. The BMD of the lumbar spine and of the proximal femur of the non-operated side was measured by dual- energy x-ray absorptiometry. A questionnaire was given to determine life-style factors, medical history and medication. Ten patients were osteoporotic, 21 osteopenic and 17 normal according to the WHO definition.

Eighteen patients suffered fractures after receiving chemotherapy and all had significantly lower levels of BMD for all the sites measured.

Ten patients underwent endoprosthetic replacement of the distal humerus for bone tumours over a period of 30 years. There were eight primary and two secondary tumours in four men and six women with a mean age of 47.5 years (15 to 76). The mean follow-up was eight years (9 months to 31 years). Four patients required further surgery, three having revision for aseptic loosening; two of these and one other later needing a rebushing. There were no cases of postoperative nerve palsy, infection, local recurrence or mechanical failure of the implant. Four patients died from their disease, all with the prosthesis functioning satisfactorily. At follow-up the mean flexion deformity of the elbow was 15° (0 to 35) and the mean range of flexion was 115° (110 to 135). The functional results showed a mean Toronto extremity salvage score of 73% of normal. Endoprosthetic replacement of the distal humerus and elbow is a satisfactory method of treating these rare tumours.

The role of radiotherapy and/or surgery in the local treatment of Ewing’s sarcoma has still to be determined. The outcome of Ewing’s sarcoma may differ according to its location and a selection bias towards surgery limits the ability to compare methods of local treatment. We have carried out a retrospective review of 91 consecutive patients treated for non-metastatic Ewing’s sarcoma of the femur. They received chemotherapy according to four different protocols. The primary lesion was treated by surgery alone (54 patients), surgery and radiotherapy (13) and radiotherapy alone (23). One was treated by chemotherapy alone.

At a median follow-up of ten years, 48 patients (53%) remain free from disease, 39 (43%) have relapsed, two (2%) have died from chemotherapeutic toxicity and two (2%) have developed a radio-induced second tumour.

The probability of survival without local recurrence was significantly (p = 0.01) higher in patients who were treated by surgery with or without radiotherapy (88%) than for patients who received radiotherapy alone (59%). The five- and ten-year overall survival rates were 64% and 57%, respectively. Patients who were treated by surgery, with or without radiotherapy, had a five- and ten-year overall survival of 64%. Patients who received only radiotherapy had a five- and ten-year survival of 57% and 44%, respectively.

Our results indicate that in patients with Ewing’s sarcoma of the femur, better local control is achieved by surgical treatment (with or without radiotherapy) compared with the use of radiotherapy alone. Further studies are needed to verify the impact of this strategy on overall survival.

In 11 patients juxta-articular osteosarcoma around the knee was treated by intraepiphyseal excision of the tumour and reconstruction of the bone defect by distraction osteogenesis. Preoperative and postoperative chemotherapy was given to eight patients with high-grade tumours. The articular cartilage of the epiphysis and a maximum of healthy soft tissues were preserved. Distraction osteogenesis was then carried out.

The mean gain in length was 9.7 cm. Full function of the limb was preserved in all except one patient, with a mean follow-up of 53.8 months. Treatment of juxta-articular osteosarcomas around the knee with joint preservation and biological reconstruction using distraction osteogenesis can give excellent functional results.

Autogenous bone graft which has been either autoclaved or irradiated is commonly used in oriental countries as an alternative to allograft. We started to use the technique of extracorporeal irradiation of the resected specimen and reimplantation (ECIR) in 1991. There was, however, a high incidence of fracture of the irradiated bone and loss of articular cartilage. In an attempt to reduce these complications, we combined the irradiated autograft with a conventional arthroplasty. Between 1995 and 1998, 14 patients underwent limb salvage by this method. Seven had an osteosarcoma, two bony metastases, three a chondrosarcoma, one a malignant fibrous histiocytoma, and one a leiomyosarcoma. Ten tumours were located in the proximal femur, two in the proximal humerus, and two in the distal femur.

One patient who had a solitary metastasis in the proximal part of the left femur died from lung metastases 13 months after operation. The remaining 13 patients were alive and without evidence of local recurrence or distant metastases at a mean follow-up of 43 months (28 to 72). Postoperative palsy of the sciatic nerve occurred in one patient, but no complications such as wound infection, fracture, or nonunion were seen. All host-irradiated bone junctions healed uneventfully within eight months. Using the Enneking functional evaluation system, the mean postoperative score for all 14 patients was 80% (57 to 93).

The use of irradiated autograft prosthesis composites reduces the complications of ECIR and gives good functional results. It may be a good alternative in limb-salvage surgery, especially in countries where it is difficult to obtain allografts.

Giant-cell tumour of the tendon sheath (GCT-TS) is a benign solitary tumour which usually arises in the limbs. It occurs most often in the hand where local recurrence after excision has been reported in up to 45% of cases. It is less common in the foot where the biological behaviour and risk of local recurrence have not been defined. We have studied 17 cases of GCT-TS of the foot and ankle in which treatment was by excision. Fifteen presented as a solitary, painless, slow-growing soft-tissue swelling. One lesion was associated with sensory deficit of a digital nerve and one with pain on walking. Thirteen cases originated from the periarticular tendon-sheath complex of the small joints of the toes and four from the capsule or long tendons of the ankle. A correct preoperative diagnosis was made in only three cases. MRI proved to be the most useful preoperative investigation as GCT-TS has a characteristic appearance which allows planned local excision to be carried out. None of the patients with histologically confirmed GCT-TS required further surgery. There was no local recurrence in 15 patients who were available for follow-up at a mean of 85 months.

Low-grade surface tumours of bone may theoretically be treated by hemicortical resection, retaining part of the circumference of the cortex. An inlay allograft may be used to reconstruct the defect. Since 1988 we have performed 22 hemicortical procedures in selected patients with low-grade parosteal osteosarcoma (6), peripheral chondrosarcoma (6) and adamantinoma (10).

Restricted medullary involvement was not a contraindication for this procedure.

There was no evidence of local recurrence or distant metastasis at a mean follow-up of 64 months (27 to 135). Wide resection margins were obtained in 19 patients. All allografts incorporated completely and there were no fractures or infections. Fractures of the remaining hemicortex occurred in six patients and were managed successfully by casts or by osteosynthesis. The functional results were excellent or good in all except one patient.

Hemicortical procedures for selected cases of low-grade surface tumours give excellent oncological and functional outcomes. There was complete remodelling and fewer complications when compared with larger intercalary procedures. The surgery is technically demanding but gives good clinical results.

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.

Giant-cell tumours of the sacrum are difficult to treat. Surgery carries a high risk of morbidity, local recurrence and mortality. Radiation is effective in some patients, but has a risk of malignant change.

We evaluated the effectiveness of serial arterial embolisation as an alternative to surgery. Five patients with giant-cell tumours of the sacrum which had been primarily treated by serial embolisation were retrospectively reviewed for changes in the size of the tumour. In four the symptoms resolved with full return of function and arrest in the growth of the tumour. They remained free from growth, recurrence, or metastases at follow-up (4 to 17 years). One patient died from metastatic disease within 18 months of the initial diagnosis.

Localised Langerhans-cell histiocytosis of bone (eosinophilic granuloma) is a benign tumour-like condition with a variable clinical course. Different forms of treatment have been reported to give satisfactory results. However, previous series all contain patients with a wide age range. Our aim was to investigate the effect of skeletal maturity on the rate of recurrence of isolated eosinophilic granuloma of bone excluding those arising in the spine.

We followed up 32 patients with an isolated eosinophilic granuloma for a mean of five years; 17 were skeletally immature. No recurrences were noted in the skeletally immature group even after biopsy alone. By contrast, four of 13 skeletally mature patients had a recurrence and required further surgery. This suggests that eosinophilic granuloma has a low rate of recurrence in skeletally immature patients.

Failure of massive knee endoprostheses implanted for malignant tumours of the distal femur in children presents a difficult problem.

We present the results of rotationplasty undertaken under these circumstances in four boys. They had been treated initially at a mean age of 9.5 years for a stage-IIB malignant tumour of the distal femur by resection and implantation of a massive knee endoprosthesis. After a mean period of eight years and a mean of four operative procedures, there was failure of the endoprosthesis because of aseptic loosening in two and infection in two. Function was poor with a mean Musculoskeletal Tumor Society score of 7.5/30, and considerable associated psychological problems.

At a mean follow-up of 4.5 years after rotationplasty there was excellent function with a mean score of 27.5/30 and resolution of the psychological problems.

We studied 55 patients with stage-IIB osteosarcoma around the knee with respect to the expression of matrix metalloproteinase (MMP)-9 in the surviving tumour cells in surgical resection specimens. They were followed up for a minimum of 2.5 years.

Factors significantly associated with poor overall survival were a high serum level of alkaline phosphatase at diagnosis and tumour cells expressing MMP-9 in the resection specimens. The only factor strongly associated with disease-free survival was the immunohistochemical status of tumour cells for MMP-9 in the resection specimens. The percentage of necrosis after chemotherapy failed marginally to reach statistical significance. On Cox regression analysis only MMP-9 remained significant for overall and disease-free survival.

Primary malignant tumours should be resected with wide margins. This may be difficult to apply to lesions of the spine. We undertook total vertebrectomy on seven patients, four males and three females with a mean age at operation of 26.5 years (6.3 to 45.8). The mean follow-up was 52.3 months. Histological examination revealed a Ewing’s sarcoma in two patients and osteosarcoma, leiomyosarcoma, spindle-cell sarcoma, chondrosarcoma and malignant schwannoma in one each. In five patients, histological examination showed that a wide resection had been achieved. At follow-up there was no infection and a permanent neurological deficit was only seen in those patients in whom the surgical procedure had required resection of nerve roots. Despite the high demands placed on the surgeon and anaesthetist and the length of postoperative care we consider total vertebrectomy to be an appropriate procedure for the operative treatment of primary malignant lesions of the spine.

In 251 patients over a period of 15 years an uncemented Kotz modular femoral and tibial reconstruction mega prosthesis was implanted after resection of a malignant tumour of the lower limb. Twenty-one patients (8.4%) underwent revision for aseptic loosening, again using an uncemented prosthesis, and five of these required a further revision procedure. The median follow-up time from the first revision was 60 months (11 to 168) and after a second revision, 33 months (2 to 50). The probability of a patient avoiding aseptic loosening for ten years was 96% for a proximal femoral, 76% for a distal femoral and 85% for a proximal tibial implant.

At the time of follow-up all radiographs were assessed according to the International Symposium of Limb Salvage criteria. The first radiological signs of aseptic loosening were always seen at the most proximal or distal part of the anchorage stem at a mean of 12 months (4 to 23) after the first implantation. Using the Musculoskeletal Tumor Society score for evaluation, the clinical results showed a mean of 88% of normal function.

From the European Osteosarcoma Intergroup study 202 patients were assessed with respect to their surgical treatment. Although treated in three different centres the survival of the three groups was identical (57% at five years). Two of the centres had rates of limb salvage of 85% and 83%, respectively, while the third had a rate of 49%. The corresponding risks of local recurrence were 13.3%, 6.8% and 2.5%, with all local recurrences arising in limbs with attempted limb salvage. Local recurrence was closely related to the adequacy of the margins of excision and to the chemotherapeutic response. Patients who had undergone limb-salvage surgery and who developed local recurrence still survival at five years). Of patients who relapsed, 31% of those with local recurrence alone were cured by further treatment, as compared with only 10% of those with metastases. Limb-salvage surgery with effective chemotherapy remains the optimum treatment for osteosarcoma.

We describe a consecutive series of 26 patients with simple bone cysts who were treated by curettage, multiple drilling and continuous decompression by the insertion of either a cannulated screw or a pin. In the first 15 patients we used titanium cannulated screws (group 1) and in the next 11 a cannulated hydroxyapatite pin (group 2). Satisfactory healing was achieved in 12 patients in group 1 (80%) and in all in group 2. This technique seems to be a promising option for the treatment of simple bone cysts. The cannulated hydroxyapatite pin is recommended because of its higher success rate and the fact that it does not need to be removed.

We treated 106 patients with a peripheral osteoid osteoma by conventional surgical methods; 81 had curettage and 25 en-bloc resection.

The rate of local recurrence after curettage was 12% and after en-bloc resection 4.5%. Postoperative fractures were observed in 3% after curettage and in 4.5% after en-bloc resection.

We compared our findings with those reported in the literature after minimally invasive treatment and concluded that curettage can be regarded as the treatment of choice in patients in whom minimally invasive methods do not offer any advantage, for example, for subperiosteal tumours which are readily accessible, or when the diagnosis is unclear and further histological analysis is required.

We have studied 560 patients with osteosarcoma of a limb, who had been treated by neoadjuvant chemotherapy, in order to analyse the incidence of local and systemic recurrence according to the type of surgery undertaken. Of these, 465 patients had a limb-salvage procedure and 95 amputation or rotationplasty.

At a median follow-up of 10.5 years there had been 225 recurrences. The five-year disease-free survival and overall survival rates were 60.7% and 68.5%, respectively, with no significant difference between patients undergoing amputation and those undergoing resection. The incidence of local recurrence was the same for patients treated by either amputation or limb salvage and correlated significantly with the margins of surgical excision and the histological response to chemotherapy. The outcome for patients with a local recurrence was significantly worse than for those who had recurrent disease with metastases only.

We conclude that limb-salvage procedures are relatively safe in osteosarcoma treated by neoadjuvant chemotherapy. They should, however, only be performed in institutions where the margins of surgical excision and the histological response to chemotherapy can be accurately assessed. If the margins are inadequate and the histological response to chemotherapy is poor an immediate amputation should be considered.

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.

We describe 25 patients who were treated for a tumour of the proximal femur by resection and replacement with an uncemented, bipolar, modular prosthesis. When followed up after more than ten years four prostheses (16%) had required revision. Two joints showed wear and another necrosis of the acetabulum. One patient with loosening of the stem had been treated by radiotherapy to the femur. Articular cartilage seemed to be a reliable barrier to acetabular wear. Very few signs of the formation of particulate debris were observed. The most obvious feature in the bone-stem relationship was stress shielding, seen as osteoporosis of the proximal part of the femur around the stem in 68%. Functional activity was satisfactory in 68% of the patients. A better system of reattachment of the soft tissues is needed to avoid pain and a persistent limp.

We considered whether a positive margin occurring after resection of a soft-tissue sarcoma of a limb would affect the incidence of local recurrence. Patients with low-grade liposarcomas were expected to be a low-risk group as were those who had positive margins planned before surgery to preserve critical structures. Two groups, however, were expected to be at a higher risk, namely, patients who had undergone unplanned excision elsewhere with a positive margin on re-excision and those with unplanned positive margins occurring during primary resection.

Of 566 patients in a prospective database, 87 with positive margins after limb-sparing surgery and adjuvant radiotherapy were grouped according to the clinical scenario by an observer blinded to the outcome. The rate of local recurrence differed significantly between the two low- (4.2% and 3.6%) and the two high-risk groups (31.6% and 37.5%). This classification therefore provides useful information about the incidence of local recurrence after positive-margin resection.

A continuous ambulatory activity monitor allows objective measurement of the amount and intensity of physical activity. We examined the reliability and validity of this device in the assessment of seven aspects of function over a period of 24 hours in 20 patients who had undergone limb salvage or amputation for a tumour in the leg.

The test-retest reliability was determined by undertaking identical assessments on two separate days. The measurements were compared with other indicators of functional status and quality of life in order to determine the validity of the monitor.

Its reliability was satisfactory, with intraclass correlation coefficients ranging from 0.65 to 0.91. Significant correlations were seen between the ‘time spent walking’ and the Musculoskeletal Tumor Society rating scales and the Rand-36 physical functioning score. There was also a significant association between the ‘movement intensity during walking’ and the Musculoskeletal Tumor Society score. The satisfactory reliability and validity of the monitor shows considerable promise for its use as a device for measuring physical activity objectively in patients after surgery for limb-salvage or an amputation.

A mucoid pseudocyst of a peripheral nerve is a rare and benign tumour of controversial origin. We have reviewed ten patients with a mean follow-up of 3.2 years. The tumour affected the common peroneal nerve in eight and the ulnar nerve in two. The mean time between the onset of symptoms and diagnosis was 7.4 months (1.2 months to 2 years). On examination, there was pain in eight patients and swelling in seven. Motor deficit in the corresponding nerve territory was found in all. The diagnosis was usually confirmed by MRI. Treatment was always surgical.

All the patients recovered, with a mean time to neurological recovery of 10.75 months. Recurrence was seen in only one patient and was treated successfully by further surgery. Our results are similar to those reported by other authors. A successful surgical outcome depends on early diagnosis before neurological damage has occurred.

We present three cases of intramuscular haemangioma adjacent to bone in the lower limb. All patients had local pain during the third decade. Plain radiographs showed an irregular or hypertrophic periosteal reaction on the shaft of the fibula and an intramuscular mass adjacent to the bone with inhomogenous high signal intensity on MRI. These lesions mimic periosteal or parosteal tumours.

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.

We treated 75 patients with benign bone tumours by curettage and filling the defect with calcium hydroxyapatite (HA). There were 28 women and 47 men with a mean age of 27.7 years (3 to 80). The mean follow-up was for 41.3 months. Postoperative radiological assessment revealed that the implanted HA was well incorporated into the surrounding host bone in all patients. Two patients suffered fractures in the postoperative period. Two patients complained of pain associated with HA in the soft tissues, but this diminished within six months. No patient had local pain at the final follow-up. Recurrence of the tumour was seen in three cases. Histopathological study of the implanted area showed removal of the HA by histiocytes and multinucleated giant cells, and the formation of much appositional bone. We conclude that HA is an excellent bone-graft substitute in surgery for benign bone tumours.

We report the results of a prospective study of 23 patients in which interstitial laser photocoagulation (ILP) was used to treat an osteoid osteoma. ILP is a technique in which tumour tissue is destroyed by direct heating using low-power laser light energy delivered by thin (400 μm) optical fibres which are introduced percutaneously into the tumour under image guidance.

Pain was evaluated before operation and at the latest follow-up using a visual analogue scale with 0 denoting no pain and 10 the worst pain imaginable. The mean follow-up was for 15 months.

The results showed that the mean pain score decreased from 7.5 before operation to 0.95 at the latest follow-up. Fourteen patients had no pain and eight had minor discomfort, not requiring analgesia. One patient required a second procedure because placement of the fibre had not been accurate enough and one developed recurrent symptoms eight months after treatment. All patients were satisfied with the operation because of the rapid resolution of pain, the minimally invasive nature of the procedure, and the fact that there was no postoperative restriction of activity.

We treated four patients with periacetabular malignant tumours by pelvic reconstruction with a free vascularised fibular graft after resection of the tumour. The mean follow-up period was 32 months (9 to 39). The diagnosis was chondrosarcoma in three patients and osteosarcoma in one. In two patients total resection of the hemipelvis was required and in the other two less, but still massive, resection was undertaken. All were treated with an immediate free vascularised fibular graft which included arthrodesis of the hip and reconstruction of the pelvic ring.

One patient died. The other three have remained free from recurrence. Solid union of the graft was achieved between four and 14 months after surgery. Shortening of the involved limbs was less than 2 cm. The patients had no pain and were independent walkers without external support. Emotional acceptance was satisfactory.

Our results suggest that reconstruction with the use of a free vascularised graft is an alternative to other types of reconstructive procedure after resection of periacetabular tumours.

We assessed the results of 17 limb-salvage procedures using osteoarticular allografts after wide resection of high-grade malignant bone tumours. All patients received chemotherapy. At the five-year follow-up, three patients had died from metastases. The allografts survived for five years in only seven patients all of whom had good function, ranging from 73% to 90% of normal. The allografts were removed because of fracture in seven patients and infection in one, and in all of these a second limb-salvage procedure was undertaken.

With such a low rate of survival of osteoarticular allografts, we believe that their use in the management of high-grade malignant bone tumours should, at best, be considered a temporary solution.

We have previously shown that cytological diagnosis based on fine-needle aspiration biopsy (FNAB) is a safe and efficient method for the discrimination between benign, primary malignant and metastatic bony lesions. We have now studied metastatic lesions to assess the diagnostic accuracy and to ascertain whether FNAB allows identification of the primary lesion.

Between 1990 and 1997, 447 patients were referred for diagnosis of skeletal lesions of unknown type. Of these 119 proved to have metastatic disease, either myeloma or lymphoma. Nine were excluded leaving 110 consecutive patients with metastatic carcinoma (80), myeloma (16) or lymphoma (14).

FNAB gave a correct diagnosis in 102 of the 110 patients (93%). In eight it was inconclusive. It correctly diagnosed 15 of 16 patients with myeloma, 12 of 14 with lymphoma, and 75 of 80 with metastatic carcinoma. Furthermore, the site and type of malignancy were correctly suggested in two-thirds of patients with metastatic carcinoma. Overall, only seven open biopsies were carried out.

We conclude that time-consuming and costly investigations can be reduced by choosing FNAB as the initial diagnostic method for skeletal lesions of unknown origin. The choice of radiological examinations, laboratory tests and surgical biopsies can be determined by using FNAB.

We describe a patient who developed avascular necrosis of both humeral trochleae after combination chemotherapy for acute lymphoblastic leukaemia. This presented as progressive stiffness of both elbows with little pain. Radiography and MRI confirmed the presence of avascular necrosis at both sites. This region corresponds to a watershed between the medial and lateral vascular arcades which supply the distal humerus and may explain the susceptibility of this bony region to avascular necrosis. Treatment involved capsulectomy of the elbow and removal of osteophytes giving a good functional outcome on both sides.

We analysed the gait characteristics of 15 patients with prosthetic reconstruction of the proximal femur after resection of a malignant bone tumour using stride analysis and measurement of oxygen consumption. Compared with normal volunteers their gait was slower, with less cadence and reduced stride length. The mean net energy cost of free walking was 141% of normal. The degree of asymmetry of the single-limb support time correlated with the free-walking velocity and the net energy cost. If they used a single cane the subjects walked with less cadence, longer stride length, and prolonged single-limb support times. The net energy cost of walking and asymmetry of the single-limb support time had a negative correlation with the strength of the hip abductor muscles. Their walking performance was better than that of six subjects who had hip disarticulation.

The systemic effects of diabetes mellitus are well recognised. The heart, kidney, central and peripheral nervous systems, and the distal parts of the limbs are often the site of end-organ damage resulting from ischaemia. Infarction of large muscle groups in the limb, not associated with gangrene, is uncommon. There have been few reported cases other than radiological descriptions of diabetic muscle infarcts. While previous reports have illustrated some of the clinical and radiological characteristics of this condition, the paucity of published cases makes it difficult to determine the most appropriate methods of diagnosis and treatment.

During a five-year period we treated 14 patients with diabetes mellitus, aged from 32 to 59 years, who were referred to a musculoskeletal oncology service for suspected soft-tissue sarcoma, but were subsequently found to have a diabetic muscle infarct. Closed needle biopsy was performed in 13 without complications. In 12 patients, the symptoms resolved without surgical treatment.

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 have studied 35 patients with infected reconstructions after segmental resection for bone tumours. Two different regimes of treatment were employed both of which entailed debridement and the use of cement impregnated with antibiotic. In 25 patients gentamicin-PMMA beads were used and in ten an antibiotic-impregnated cement spacer. Better results were achieved with the second procedure in terms of cases healed, the number of operations, time of healing, time of recovery and the functional score. The use of vancomycin in the cement spacer gave better local control.

We describe the functional results in 14 patients (7 men, 7 women) after subtotal scapulectomy for primary bone and soft-tissue tumours at a specialist musculoskeletal oncology unit. Eight had chondrosarcomas, two Ewing’s sarcomas, one aggressive fibromatosis and three soft-tissue sarcomas. The mean follow-up was 52 months (6 to 120). Analysis of residual symptoms and of range and strength of movement by physicians used the Musculoskeletal Tumour Society rating scale (MSTS). Physical disability was measured by the patients using the Toronto Extremity Salvage Score (TESS).

All 14 patients are still alive, two with systemic disease. Nine had more than 80% of their scapula resected but the glenohumeral joint was preserved in all cases. Eight had full movement and another two achieved 90° of flexion. The mean functional results were good to excellent in all except three patients (mean MSTS = 71.6 and TESS = 79.9). Two of these three patients had considerable pain as a result of brachial neuropathy.

Scapulectomy gives an excellent functional result if the glenohumeral joint is preserved. The rotator cuff could be removed without a severe functional deficit provided that the deltoid was reattached to the scapular remnant and the trapezius.

We reviewed 23 patients with a giant-cell tumour (GCT) of bone and histologically-proven lung metastases at a mean of 11.9 years (3 to 24.5) after the original diagnosis.

The mean age of the patients at diagnosis was 27.3 years (9 to 61); the male to female ratio was 0.9:1. The most common primary site was the distal radius. The mean interval between the onset of the tumour and the detection of lung metastases was 4.1 years (0 to 24). There had been local recurrence in 19 (83%) either before or at the time of diagnosis of lung metastasis.

Surgical resection alone was the preferred treatment for lung metastases in 70% and resulted in 18 patients (76%) being free from disease when last reviewed. One patient had the spontaneous regression of lung metastases and was free from recurrence 16 years later. Sixteen patients (69.7%) have survived and four (17.4%) have died from progression of the tumour. Three other deaths were not related to the tumour.

Local recurrence and a primary lesion at the distal radius seem to be associated with an increased risk of lung metastases. Repeated surgical resection of lung metastases gave a high rate of survival.

The use of extendible distal femoral replacements is a relatively new treatment alternative for malignant bone tumours in growing individuals. Although their appearance was widely appreciated, questions about functional practicality and longevity remain unclear. With longer follow-up, advantages of immediate functional restoration and beneficial psychological aspects seem to be overshadowed by an increase in complications such as aseptic loosening, infection or prosthetic failure.

We have reviewed 18 children with such tumours who were treated between 1983 and 1990 by custom-made Stanmore extendible distal femoral replacements. Four died from metastatic disease within 2.5 years of operation and two required amputation for local recurrence or chronic infection.

The remaining 12 patients were followed for a mean of 8.7 years (6 to 13.2). A mean total lengthening of 5.2 cm was achieved, requiring, on average, 4.3 operations. Using the Musculoskeletal Tumor Society rating score the functional result at review was, on average, 77% of the expected normal function, with seven patients achieving ≥ 80%. Revision of the prosthesis was required in ten patients, in six for aseptic loosening, at a mean of 6.2 years after the initial procedure.

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 277 patients with soft-tissue sarcoma (STS) treated between 1975 and 1995 to study the incidence, distribution, time of appearance, and radiological findings of skeletal metastases. Of these, 28 (10.1%) had metastases within a mean period of 18.6 months after admission.

The incidence of skeletal metastases differed among the histological subtypes of sarcoma; alveolar soft-part sarcoma, dedifferentiated liposarcoma, angiosarcoma, and rhabdomyosarcoma tended to show higher incidences. The regional bones close to the primary tumour were affected in 13 (46.4%) of the 28 patients, and the axial bones in 18 (64.3%). Radiologically, the metastatic bony lesions predominantly showed osteolytic changes, and there were pathological fractures in 21 of 44 lesions.

We have investigated the significance of local recurrence on survival in 173 patients with localised soft-tissue sarcomas of the limbs and of the trunk.

The overall survival rates at five and ten years were 75.2% and 68.0%, respectively. After definitive surgery at our hospitals, there was local recurrence in 25 patients (14.5%). After inadequate operations elsewhere, there was a higher incidence of late local recurrence (28.3%), in comparison with those with primary tumours treated by us (9.0%), or patients referred to us immediately after inadequate surgery elsewhere (10.2%). Because of small numbers these differences in the survival rates were not statistically significantly different.

Univariate survival analysis showed that local recurrence after definitive surgery (p = 0.006) together with the histological grade (p = 0.0002), the size of the tumour (p = 0.002), its depth in relation to deep fascia (p = 0.003), and the surgical margin (p = 0.0001) were the significant prognostic factors. Local recurrence at the initial presentation did not affect survival. Multivariate analysis showed that local recurrence after definitive surgery also lost its apparent prognostic significance.

We report the results of distraction osteogenesis (callotasis) for the reconstruction of extensive defects after the excision of skeletal tumours in the limbs. Bone transport was performed in ten patients (five osteosarcomas and five giant-cell tumours), shortening-distraction in three (two osteosarcomas and one Ewing’s sarcoma), and distraction osteogenesis combined with an intramedullary nail to reduce the time of external fixation in six (three osteosarcomas, two chondro-sarcomas, and one malignant fibrous histiocytoma).

The mean length of the defects after excision of the lesion was 8.4 cm. The mean external fixation index was 39.5 days/cm for the group treated by bone transport, 34.1 days/cm for the shortening-distraction group, and 24.0 days/cm for the group treated by distraction and an intramedullary nail. Functional evaluation gave excellent results in 12 patients, good in five and fair in two. There were ten complications in 19 patients, all of which were successfully treated.

We also classified reconstruction using distraction osteogenesis into five types based on the location of the defects after resection of the tumour: type 1, diaphyseal; type 2, metaphyseal; type 3, epiphyseal; type 4, subarticular reconstruction; and type 5, arthrodesis.

Our results suggest that reconstruction using distraction osteogenesis provides bone which will develop sufficient biomechanical strength and durability. It is beneficial in patients with an expectation of long-term survival and in growing children.

We have reviewed 13 operations on 11 patients using curettage and polymethylmethacrylate cement for giant-cell tumour of bone (GCT) to assess the value of radiology in the early detection of recurrence. There were four recurrences, the most specific radiological sign on plain radiography was lysis of 5 mm or more at the cement-bone interface. This preceded clinical signs by a mean of four months and was identified at a mean of 3.75 months after operation. There was not always a complete sclerotic margin around the cement, but when it was present, there was never evidence of recurrence. MRI was helpful in assessing cases with evidence of recurrence.

Frequent surveillance with plain radiography should continue for one year after operation irrespective of clinical signs of recurrence. When the appearance of the plain radiographs suggests recurrence, MRI should be performed and followed by image-guided needle biopsy.

We have reviewed 30 patients at a mean of 36 months after free vascularised fibular transfer to reconstruct massive skeletal defects after resection of primary bone tumours. There were 23 malignant and 7 benign neoplasms, half in the lower limb and half in the upper. Arthrodesis was performed in 15 and intercalary bone replacement in 15. The mean fibular graft length was 189 mm.

Union was achieved in 27 (90%) at an average of 7.6 months, and the 3-year survival was 89%. There was a high complication rate (50%), but most resolved without greatly influencing the final outcome. There was local recurrence in two (6.7%), but 16 of the 24 assessed patients (67%) had satisfactory functional results. This is a reasonably effective means of reconstruction for limb salvage after resection of tumours.

We treated 26 patients with 27 aneurysmal bone cysts by curettage and cryotherapy and evaluated local tumour control, complications and functional outcome. The mean follow-up time was 47 months (19 to154). There was local recurrence in one patient. Two patients developed deep wound infections and one had a postoperative fracture.

We compared our results with previous reports in which several different methods of treatment had been used and concluded that curettage with adjuvant cryotherapy had similar results to those of marginal resection, and that no major bony reconstruction was required.

We recommend the use of cryotherapy as an adjuvant to the surgical treatment of aneurysmal bone cysts. It provides local tumour control. Combination with bone grafting achieved consolidation of the lesion in all our patients.

We have reviewed the results of one-stage revision surgery in 18 patients for infection of megaprostheses implanted after the resection of malignant bone and soft-tissue tumours.

At a mean follow-up of 52.0 ± 35.0 months (18 to 135) infection was eliminated in 14 of the 18 patients. The infection-free patients showed no abnormal tests for inflammation and had a mean Enneking score of 20.6 ± 5.0 points (maximum 30 points).

We suggest that one-stage revision without exchange of the anchorage parts is justified in patients with megaprostheses infected by antibiotic-sensitive micro-organisms.

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.

We describe a case of osteosarcoma of the scaphoid bone, which to our knowledge is only the second reported case of osteosarcoma in the carpus. A 38-year-old man complained of intense pain in the right wrist and had curettage and a bone graft for a lesion in the scaphoid. Histological examination showed this to be an osteosarcoma. Below-elbow amputation was performed and adjuvant chemotherapy given. There has been no evidence of recurrence or metastases at 33 months after amputation.

We report a unique case of juxtacortical osteoblastoma of the humeral shaft, which simulated the appearance of an extraosseous extension of Gaucher-cell deposits. The tumour was treated successfully by curettage and bone grafting. We can find no previous report of this association between osteoblastoma and Gaucher’s disease.

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.

We reviewed retrospectively 236 consecutive patients seen in our soft-tissue sarcoma clinic. Of these, 95 had had a primary soft-tissue sarcoma excised elsewhere, but with histologically inadequate resection margins. All these patients had a secondary and wider re-excision.

The tissues removed at the secondary re-excision were examined histologically for the presence of residual tumour. Definite tumour tissue was found in 29 of 55 lower-limb specimens, 16 of 25 upper-limb, 7 of 10 trunk and 4 of 5 head and neck specimens. In 31 cases some residual tumour was visible macroscopically, and in 56 of the 95 patients (59%) the primary tumour had been incompletely excised.

Our results indicate that surgical assessment of the adequacy of excision is very inaccurate and that most local recurrences are the consequence of inadequate primary surgery. The large number of patients who had inadequate initial treatment emphasises the need for a co-ordinated multidisciplinary approach to the management of patients with soft-tissue sarcoma.

We evaluated the diagnostic accuracy of fine-needle aspiration biopsy in a prospective study of 300 patients with previously undiagnosed bone lesions. Patients with suspected local recurrence of a primary bone tumour or a metastatic lesion of a previously diagnosed malignancy were excluded. Fine-needle aspiration biopsy was performed under radiological control as an outpatient procedure.

The series was grouped into three major categories: 1) benign bone lesions including infections; 2) primary malignant bone tumours; and 3) metastases including lymphomas and myelomas. We compared the cytological diagnosis with the final diagnosis as assessed by histological examination and/or the clinical and radiological features.

Material considered conclusive for cytological diagnosis was obtained from 251 of the 300 patients. Of the 49 failures, there were 24 aspirates with insufficient cellular yield and 25 in which a diagnosis could not be made although the cytological material was adequate in quantity. Most of the inconclusive aspirates (36/49) were obtained from benign bone lesions.

The diagnosis was correct in 239 (95%) of the 251 cases providing adequate cytological material. There were eight (3%) falsely benign diagnoses, one (0.3%) falsely malignant, and three cases in which we were unable to differentiate between sarcoma and a metastasis. Chondrosarcoma (2/12) gave the greatest diagnostic difficulty and Ewing’s sarcoma the least (0/9). There were no decisive errors of treatment. All falsely benign or malignant diagnoses were questioned, and led to open biopsy since they did not correlate with the clinical and radiological features.

Our study suggests that fine-needle aspiration biopsy is a valid option for the diagnosis of bone tumours. It is a simple outpatient procedure which gives sufficient cytological material for the correct diagnosis in 80% of cases. As with histological analysis of material from open biopsy, the cytological assessment must agree with the clinical and radiological findings.

We have used the Ilizarov technique for the management of subarticular defects after the excision of giant-cell tumours in the proximal tibia in five patients. The defect was reconstructed with a segment of 5 to 6 cm obtained from the diaphysis of the affected tibia and by autogenous bone graft from the iliac crest. The newly developed defect in the diaphysis was reconstructed by distraction using the Ilizarov apparatus. Bone grafting at the docking site was performed soon after positioning the bone segments.

The mean length of the bone defect was 5.7 cm and the mean duration of external fixation was 233 days. The relative blood flow in the leg measured by ^99mTc angiography increased by 1.7 to 2.3 times that of the control level during distraction and consolidation. When seen at a mean of 43 months all patients showed a normal range of motion in the knee and ankle with no collapse of the articular surfaces.

We have made a retrospective study of 1001 custom-made prostheses used as replacements after surgery for bone tumours. There were 493 distal femoral, 263 proximal femoral and 245 proximal tibial prostheses. Aseptic loosening was shown to be the principal mode of failure of the implants, and 71 patients had revision for aseptic loosening of a cemented intramedullary stem.

The probability of a patient surviving aseptic loosening for 120 months was 93.8% for a proximal femoral replacement, 67.4% for a distal femoral prosthesis and 58% for a proximal tibial implant. In patients with distal femoral replacements the age of the patient at the time of operation and the percentage of bone resected were related to the risk of aseptic loosening. Young patients with distal femoral prostheses in whom a high percentage of the femur had been replaced had the poorest prognosis for survival without aseptic loosening. The percentage of bone removed had a significant effect in the proximal tibial replacement group, but the age of the patient did not. By contrast, neither the age nor the percentage of bone removed was a factor after proximal femoral replacement.

The significance of these findings is discussed in relation to mechanical factors.

Previous studies have shown that the activity of the cytostatic drug methotrexate (MTX) embedded in acrylic cement is not affected by thermal changes in the cement. MTX is slowly released from the cement for several months and remains biologically active throughout this period. Our aim was to determine whether MTX embedded in cement would control the local growth of a tumour.

In 15 rabbits we injected 0.1 ml of VX₂ tumour suspension into the proximal tibia. At 3, 5, 7, 10 and 14 days three animals were killed and the tibiae removed and examined histologically. With increasing growth of the VX₂ carcinoma there was increased bone destruction and a rise in the numbers of osteoclasts, but after 14 days the numbers of osteoclasts had decreased.

We then injected VX₂ into the tibiae of another 45 rabbits. After 5 days most of the tumour was curetted out and the defect filled with cement containing either 0 g, 0.1 g, 0.5 g, 1.0 g or 2.0 g MTX/40 g cement. The rabbits were divided into three groups and killed at 3, 7 or 10 days after implantation of cement. The number of osteoclasts and the amount of bone destruction were measured in each tibia. In all three groups bone destruction and osteoclast proliferation were markedly decreased with higher doses of MTX, but bone destruction was not eliminated.

Our findings show that in the higher doses used, which were not toxic to the animal, MTX-embedded cement may be of value in minimising the amount of tumour-induced osteolysis and may be a useful adjunct in the surgical management of pathological fractures.