Reconstruction of type II pelvic resection with a new peri-acetabular reconstruction endoprosthesis.

We report our early experience with a new peri-acetabular reconstruction endoprosthesis used for pelvic reconstruction after tumour resection. The outcome of 21 patients who underwent limb salvage following type II pelvic resection and reconstruction using the peri-acetabular reconstruction prosthesis between 2000 and 2006 was retrospectively reviewed. This prosthesis was designed to use the remaining part of the ilium to support a horizontally placed acetabular component secured with internal fixation and bone cement. Into this device a constrained acetabular liner is positioned which is articulates with a conventional femoral component to which a modular extension and modular head are attached. The mean follow-up was 20.5 months (1 to 77). The most common complications were deep infection, superficial wound infections, and dislocation. The mean musculoskeletal tumor society functional outcome score for the survivors was 20.1(11 to 27). We recommend the use of the peri-acetabular reconstruction prosthesis for reconstruction of large defects after type II pelvic resection, as this design has a greater inherent stability over other available prostheses.

Intercalary endoprosthetic reconstruction for diaphyseal bone tumours.

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.

Survivorship and clinical outcome of modular endoprosthetic reconstruction for neoplastic disease of the lower limb.

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.

Cryosurgical ablation of soft tissue sarcomas: a phase I trial of feasibility and safety.

BACKGROUND: Cryosurgery is a therapeutic method of treating neoplastic tissue by freezing in situ to achieve devitalization. Cell death results from exposure to severe cold (below -40 degrees C for at least 1 minute) as well as from the process of freezing and thawing, which disrupts cellular integrity. Modern cryosurgical technique involves insertion of hollow probes into the tumor, through which circulating liquid nitrogen and gaseous nitrogen can achieve tissue and tumor freezing and thawing for tumor control. Cryoablation is now a recognized approach to the treatment of various malignant tumors, and it is generally well tolerated. This method has been used only sporadically to date in the treatment of patients with soft tissue sarcomas. METHODS: The purpose of this study was to assess the feasibility and safety of cryosurgical ablation of soft tissue sarcomas utilizing a cryoprobe system. Twelve patients with soft tissue tumors of the extremity were included in this Institutional Review Board-approved protocol. Cryoablation was performed by inserting cryoprobes into the tumors, through which liquid nitrogen and gaseous nitrogen were pumped to achieve two freeze/thaw cycles. The entire process was monitored with intraoperative ultrasonography. All patients had subsequent resection of the residual tumor. Patients were monitored clinically and metabolically for toxicity. RESULTS: Cryoablation was successfully performed on all 12 patients. Complications included peripheral nerve palsy (in 3 patients) and serous wound drainage (in 3 patients). There were no cases of wound infection, deep venous thrombosis, pulmonary embolism, wound dehiscence, skin slough, or metabolic abnormalities. All 3 cases of peripheral nerve palsy showed signs of recovery, 2 within 1 week and 1 within 4 months. CONCLUSIONS: Cryosurgical ablation of soft tissue sarcomas is technically safe and feasible. This method can be used in conjunction with other modalities in the treatment of patients with these tumors. The complications associated with cryoablation of sarcomas are minor or transient, and the procedure is well tolerated by patients. The role of cryosurgery in the management of soft tissue sarcomas needs to be elucidated as more data regarding its safety and effectiveness become available.

Preoperative CT localization and marking of osteoid osteoma: description of a new technique.

We describe a new technique for the preoperative localization of an osteoid osteoma nidus. Four lesions (mean patient age 26 years) were localized with CT. A needle was advanced into the cortex, methylene blue was injected, and a self-retaining localization wire was then left in place. A final CT image confirmed localization. The site of marking was identified intraoperatively by following the guide wire to the cortical mark, permitting nidus excision with minimal resection of bone.

Methotrexate eluted from bone cement: effect on giant cell tumor of bone in vitro.

The effectiveness of methotrexate eluted from polymethylmethacrylate on cell lines established from giant cell tumor of bone was investigated in vitro to determine the possible efficacy of this treatment. Elation of methotrexate from polymethylmethacrylate beads and boluses was shown in vitro to be dose dependent and limited by the size of the bolus. Cytocidal activity of methotrexate elated from polymethylmethacrylate beads prepared without monomer and of boluses of polymethylmethacrylate with the same dose of methotrexate prepared with monomer against 2 human giant cell tumor cell lines was statistically significant at 24 hours in culture. Statistical significance occurred at 24 hours in culture. Activity was maintained in vitro after 17 days. These experiments showed that eluted methotrexate remained effective against tumor cells after exposure to thermal changes during polymerization of polymethylmethacrylate. While extensive curettage of giant cell tumor of bone followed by filling in the defect with polymethylmethacrylate has become a common treatment, a local adjuvant is necessary to reduce further risk of local recurrence. A potential alternative to cryosurgery or instillation of phenol is the use of methotrexate impregnated polymethylmethacrylate to treat residual microscopic disease after curettage. This method may provide locally effective chemotherapy without the risks of systemic toxicities.

Kasabach-Merritt syndrome complicating treatment of a closed femoral fracture.

The Kasabach-Merritt syndrome of consumptive coagulopathy associated with massive hemangiomas is a potentially life-threatening problem in patients who sustain long bone fractures of the involved extremities. In this syndrome, platelet consumption is caused by their sequestration in the sinusoids and epitheloid chambers of large hemangiomas. Secondary fibrinolysis then occurs with resulting thrombocytopenia, hypofibrinogenemia, and increased fibrin degradation products that can lead to disseminated intravascular coagulation. This can result in massive bleeding even after minor trauma. In such patients, operative management of long bone fractures, including the placement of cutaneous pins for skeletal traction, may be contraindicated; nonoperative management may be necessary. Kasabach-Merritt syndrome must be suspected in patients with large hemangiomas and associated long bone fractures, and appropriate coagulation studies should be obtained before operative management or placement of percutaneous skeletal pins. Decreased hematocrit and fibrinogen levels associated with thrombocytopenia and prolonged prothrombin time and partial thromboplastin time should alert the orthopaedist to the possibility of Kasabach-Merritt syndrome, and prompt hematologic consultation should be obtained. If surgical treatment is deemed too dangerous because of the possibility of uncontrollable disseminated intravascular coagulation, the only prudent option may be a closed reduction and cast application after appropriate medical management of coagulation parameters.

Case report 797: "Dedifferentiated" lipoma-like liposarcoma of soft tissue with focal transformation to high-grade "sclerosing" osteosarcoma.

We have presented the first case of a lipoma-like liposarcoma of the soft tissues with high-grade malignant transformation to a high-grade osteosarcoma, the latter component of which responded well to systemic chemotherapy. With 4 months of follow-up the patient is without evidence of disseminated disease. The various types of liposarcoma are listed and several described in some detail. Of particular importance is the potential for development of a highly malignant sarcoma from a relatively indolent low-grade liposarcoma, with even osteosarcoma developing.

Reconstructive considerations for limb salvage surgery.

Tumors in the musculoskeletal system are generally treated surgically, although radiation therapy and chemotherapy have greatly improved survival statistics of patients with high-grade sarcomas of the musculoskeletal system. The mainstay in treatment of nearly every primary tumor of the musculoskeletal system is surgical resection for cure. Radiation therapy and chemotherapy continue to be important adjuvants in the overall management of musculoskeletal tumors. Functional limb salvage following radical resection is now possible in most resectable cases by placement of an alloplastic prosthesis, homograft, or autogenous bone for skeletal reconstitution, followed by well-vascularized soft-tissue coverage.

Thallium-201 scanning for the evaluation of osteosarcoma and soft-tissue sarcoma. A study of the evaluation and predictability of the histological response to chemotherapy.

We evaluated sequential thallium scans, made before and after a period of preoperative chemotherapy, for sixteen patients who had a high-grade sarcoma of bone or soft tissue. The purpose was to determine whether this technique could be used to ascertain accurately the amount of viable tumor as well as to predict the response to chemotherapy. Nine of the ten patients who had a reduced thallium uptake after chemotherapy also had a marked histological response, with necrosis of the tumor of at least 95 per cent. Six patients were seen to have no improvement on the thallium scans, and this finding correlated with necrosis of the tumor of less than 95 per cent. Thallium chloride has been shown to have an affinity for a variety of osteosarcomas and soft-tissue sarcomas. The mechanism of intracellular uptake is one of active transport, which makes thallium chloride a more accurate barometer of the viability of the tumor cells and of metabolic activity than scanning agents that are flow-dependent. We believe that sequential thallium scintigraphy should be used in conjunction with other imaging modalities in the diagnosis, planning of treatment, and follow-up evaluation of patients who have a sarcoma of bone or soft tissue. This technique appears to be useful in the prediction of the histological response of high-grade osteosarcomas and soft-tissue sarcomas to preoperative chemotherapy.

Bone remodelling in the presence of chondrosarcoma: histomorphometry.

Accurate knowledge of tissue changes near bone tumors can contribute to a better understanding of tumor behavior. We have used tumor ultrastructure and quantitative bone histomorphometry to evaluate local bone/tumor features associated with a low grade chondrosarcoma in a 39-year-old male. Three noninvolved sites and two sites near the tumor in the proximal femur were studied with bone morphometry. Bone near the tumor showed increased percent osteoid surface, percent osteoid volume and fraction of osteoid surface lined by osteoblasts compared to distant noninvolved sites. Both the number of osteoblasts and mean individual osteoblast size were significantly increased compared to noninvolved sites. Osteoclast number and percent osteoclast surface were also increased near the tumor. Ultrastructural studies of tumor tissue revealed two types of tissue: synthetic mesenchymal cells and cartilage tissue. Results indicate increased bone formation and resorption near the tumor. These local bone changes may possibly reflect responses to local tumor factors and depend on the extent of the tumor.

Synovial sarcoma. A clinicopathologic study.

Twenty-five cases of synovial sarcoma were reviewed clinically, roentgenographically, and pathologically. The histopathology of each tumor was classified as either monophasic (19 cases) or biphasic (six cases). A soft-tissue mass was seen on roentgenography in 70% of patients; calcification was present in 15% of cases. Treatment included surgery, with or without radiation and/or chemotherapy. Fifteen patients remained disease free at an average of 7.5 years, one patient had pulmonary metastasis, and nine patients have died. The critical prognostic factor was adequate surgical margins; there were no local recurrences with adequate tumor-free margins, but there was an 83% recurrence rate with inadequate treatment.

Malignant tumors of the upper extremity in children.

Of the 422 primary malignant tumors of bone and soft tissue treated at one institution between 1968 and 1988, the 29 found in the upper extremity in children are reviewed. In the latter group, there were 13 patients with osteosarcoma; one was lost to follow-up shortly after diagnosis, one was alive and disease free four years after surgery, two are currently being followed, and nine are dead. All of the four patients with Ewing's sarcoma died. Three patients had chondrosarcoma; one was lost to follow-up after surgery, and the other two were disease free at four and 14 years' follow-up. Two of the nine patients with soft-tissue sarcomas died as a result of their tumors.

Fat embolism syndrome complicating intraarterial chemotherapy with cis-platinum.

A 19-year-old man with telangiectatic osteosarcoma of the left proximal femur was started on a course of neoadjuvant chemotherapy consisting of intraarterial administration of cis-platinum. Within 72 hours of receiving the first intraarterial dose, the patient developed signs and symptoms of fat embolism syndrome (FES). A physical examination revealed cyanosis, tachycardia, and seizure activity. Laboratory studies demonstrated a pO2 of less than 65 mmHg, lipuria, and a drop in hematocrit of three percentage points. There was no clinical or roentgenographic evidence of pathologic fracture. Tumor necrosis secondary to intraarterial cis-platinum therapy in this patient with osteosarcoma may have caused a sudden release of free fatty acids and embolization of fat macroglobules that precipitated this episode of FES. FES in association with the intraarterial administration of cis-platinum seems not to have been previously reported.

Neurofibroma in a patient with von Recklinghausen's disease seen as a malignant schwannoma. A case report.

A rapidly growing, malignant schwannoma occurred in a 46-year-old woman with neurofibromatosis. Computed tomography, isotope bone scan, chest roentgenogram, and angiogram are helpful in determining the local extent and distant spread of such musculoskeletal tumors and are useful in planning appropriate surgical management. A well-planned biopsy, however, is essential to accurately determine the histologic diagnosis of the tumor. Clinical and roentgenographic presentation of some benign lesions may mimic malignant tumors. To confirm the diagnosis of a malignant or benign tumor, it is advisable to examine the musculoskeletal tumor histologically before proceeding with the definitive treatment, even if the clinical presentation strongly suggests malignancy.

Diaphyseal intraosseous ganglion.

Ganglion cysts of bone are noted to occur most often in the metaphysis of epiphysis of a long bone. A unique ganglion cyst, developing in a diaphyseal location, was excised from the leg of a 14-year-old boy. The follow-up examination showed no recurrence one year following surgery.