Single-bone forearm reconstruction for malignant and aggressive tumors.

UNLABELLED: Limb-salvage surgery for malignant and aggressive forearm tumors presents a unique surgical challenge. We performed single-bone forearm reconstructions after extensive resections of the radius and ulna in four patients for such tumors. Radiocarpal arthrodesis was performed in three patients. We recorded the presence of metastases or local recurrences, Musculoskeletal Tumor Society upper extremity scores, and complications. One patient had local recurrence and one died of metastases. The average Musculoskeletal Tumor Society score at the last followup was 26 of 30 (88%; range, 24-28). Complications included wound infection/necrosis, delayed union, nonunion, and acute carpal tunnel syndrome. Single-bone forearm reconstructive surgery provided satisfactory functional outcomes in these four patients, and we believe it is a reasonable treatment option for individuals with malignant or aggressive tumors of the forearm requiring massive bone resection. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Treatment of advanced metastatic lesions of the acetabulum using the saddle prosthesis.

Current methods of treating advanced patients with metastatic periacetabular disease are complex and result in high complication rates. The purpose of this study was to show whether the implantation of the saddle prosthesis would serve as an additional tool to help treat metastatic disease in these patients. From 1991 to 2003, 20 patients with advanced metastatic periacetabular lesions (Harrington Class III) were treated using the saddle prosthesis. Goals of surgery were a decrease in pain, functional restoration, and ambulation. The mean age was 61 years. Average length of followup was 20 months. Postoperatively, ambulation was achieved in 16 of 20 patients. There were four postoperative complications (20%) in three patients. Surgical goals were met in 18 of 20 patients. The MSTS-ISOLS emotional score was 2.9 of 5. The average total MSTS-ISOLS score was 16.6 of 30 (55%). Using the Allan scoring system consisting of analgesia, independence and ambulation, and mobility, all scores had significant improvements postoperatively. Careful surgical indications and technique should result in a stable, functional reconstruction allowing patients the ability to ambulate outside the house with a cane. Patients can expect to be emotionally satisfied with the procedure while using nonnarcotic analgesia and can expect an improved quality of life despite bone metastasis.

Alveolar soft part sarcoma--reciprocal translocation between chromosome 17q25 and Xp11. Report of a case with metastases at presentation and review of the literature.

The molecular pathogenesis of alveolar soft part sarcoma, a rare tumor with uncertain histogenesis, was elucidated recently and was shown to be due to a translocation between chromosome 17q25 and Xp11 resulting in a fusion product between TFE3 (a transcription factor gene) at chromosome Xp11 and a novel gene designated as ASPL at chromosome 17q25. This results in the transcriptional dysregulation in the pathogenesis of this neoplasm. Of the 12 cases reported so far, the translocation was due to non-reciprocal translocation in 11 cases with only one case demonstrating a reciprocal translocation with respective fusion products. We report yet another case with reciprocal translocation between chromosomes 17q25 and Xp11 with TFE3/ASPL fusion product who presented with metastatic disease. A standard cytogenetic analysis of primary tumor cells with G-banding revealed an abnormal karyotype: 46, X, t(X;17)(p11;q25)[15]/46,XX[5]. PCR analysis of the frozen tumor tissue revealed a type 1 fusion product as described in the literature. We demonstrate a rare cytogenetic abnormality in ASPS, namely reciprocal translocation between chromosomes 17q25 and Xp11 with demonstration of molecular fusion product between TFE3 and ASPL in a patient who initially presented with pulmonary metastases.

Osteomyelitis originating in and around bone infarcts: giant sequestrum phenomena.

OBJECTIVE: We describe four cases of osteomyelitis that occurred in and around foci of preexisting osteonecrosis in the medullary cavity. Although sequestration is a well-known complication of osteomyelitis, there is little information known about infection occurring in proximity to large regions of already necrotic bone. CONCLUSION: Osteomyelitis and bone infarction can be seen in the same patient population. Medullary infarcts may function as sequestra, predisposing patients to osteomyelitis and soft-tissue infection.

Perioperative considerations in patients with metastatic bone disease.

Preoperative assessment of patients with metastatic bone disease includes a history and physical examination, laboratory evaluation, and standard radiographs. Perioperative diagnostics include technetium bone scan, CT scans, MR imaging, positron emission tomography, and biopsy. The role of preoperative tumor embolization and vena cava filter placement is discussed in this article. Guidelines for pain control are provided. Surgical planning and instrument considerations for long bone lesions, periarticular lesions, and pelvis and acetabular lesions are addressed. The importance of rehabilitation for patients with metastatic bone disease is emphasized.

Mechanical environment affects allograft incorporation.

In a bilateral canine tibial model, the mechanical, radiologic, and histologic characteristics of intercalary allografts stabilized with locked intramedullary nails were compared with those of allografts fixed with compression plates. Both methods of fixation achieved healing to host bone. Tibiae that were plated had more callus with statistically greater mean torsional rigidity and strength than those treated with nails (paired t-test, p

Pathologic supracondylar fracture due to osteolytic pseudotumor of knee following cementless total knee replacement.

Wear debris of polyethylene, polymethylmethacrylate, and metal have been recognized to be associated with foreign body reactions, osteolysis, and aseptic prosthetic loosening after joint replacement arthroplasty. Further, foreign body reaction due to the presence of extensive wear debris can cause aggressive granulomatous lesions and pathologic fracture. To our knowledge, there has been no previous report of pathologic fracture of the femur due to an agressive pseudotumor. This report describes a case of pathologic supracondylar fracture of the femur 6 years and 5 months after cementless total knee replacement arthroplasty. The fracture occurred through an aggressive expanding soft tissue mass that was a tumorlike lesion secondary to polyethylene wear debris. The lesion was associated with massive osteolysis around the femoral component of the total knee prosthesis.

"En-bloc" vertebrectomy in the mobile lumbar spine.

BACKGROUND: Primary tumors of the vertebral bodies have previously been treated with total or subtotal excision in a piecemeal fashion (intralesional excision). Radiation therapy has been used to help control tumor growth. Recurrence rates with an intralesional, piecemeal removal of vertebral tumors have been unacceptably high. This study describes a method to excise a lumbar vertebra "en-bloc," and in the process, to perform a marginal (extralesional) resection of a primary tumor of the mobile lumbar spine that allows for a potential surgical cure. METHODS: A combined posterior-anterior procedure allows for an extralesional, marginal resection of the tumor and the involved vertebra. All posterior bony elements, including the pedicles and the adjacent intervertebral discs, are removed via a posterior approach. An anterior, retroperitoneal approach is then used to remove the vertebral body/tumor as a single specimen. The nerve roots at the involved levels are spared and the spine is instrumented and fused both posteriorly and anteriorly. RESULTS: Three patients successfully had combined posterior-anterior resections of lumbar vertebral chordomas. No permanent neurological complications occurred. Overall morbidity of the procedure was acceptable. At 31-month follow-up, no tumor recurrence has been detected. CONCLUSIONS: "En-bloc" resection of a primary vertebral tumor of the lumbar spine is technically demanding, but potentially curative. The alternative approaches-intralesional excision, radiation therapy, or a combination-are unable to cure these tumors. Long-term, 10-year follow-up will be necessary to confirm whether this en-bloc approach provides a surgical cure.

Synovial sarcoma: frequency of nonaggressive MR characteristics.

PURPOSE: Our objective was to examine the MR characteristics of synovial sarcoma and determine the frequency of a nonaggressive imaging appearance. METHOD: Fifteen patients with histologically confirmed cases of synovial sarcoma and prior MR examinations were seen. Retrospective analysis of imaging features included assessment of size, margins, homogeneity, internal architecture, T1- and T2-weighted signal intensities, and bone invasion. RESULTS: Five of 15 patients (33%) had well circumscribed, homogeneous lesions with a mean length of 4.8 cm. The T1-weighted signal intensity was either isointense to muscle or greater in signal intensity than muscle. The T2-weighted images demonstrated signal intensity equal to or greater than fat. The remaining 10 lesions were larger (mean length of 11.3 cm) with mild to complex levels of inhomogeneity and margins that varied from well circumscribed to infiltrating. CONCLUSION: There are two sets of MR features seen with synovial sarcoma. Small lesions of -5 cm can demonstrate a nonaggressive appearance with well circumscribed margins and homogeneous signal intensity. These tumors could be confused with benign lesions, resulting in inappropriate surgical intervention like excisional biopsies through transverse incisions. This would make future surgery more difficult. Larger lesions tend to be more heterogeneous in signal intensity.

Neuropathy secondary to pigmented villonodular synovitis of the hip.

Pigmented villonodular synovitis is a benign proliferative process of unknown origin that may cause extensive bone and joint destruction. Patients with this condition typically present with symptoms of mild discomfort and associated stiffness of the involved joint; however, the spectrum of presentations is broad. Although pigmented villonodular synovitis begins in, and usually is confined within, a synovium-lined joint, it may extend beyond the joint capsule and present as a soft tissue mass. Three cases of a previously unrecognized presentation of pigmented villonodular synovitis of the hip joint are presented. The authors believe these to be the first reported cases in the English language literature of pigmented villonodular synovitis of the hip seen with femoral or sciatic neuropathy.

Magnetic resonance imaging of intraosseous lipomas: a radiologic-pathologic correlation.

Four patients with intraosseous lipomas were studied with magnetic resonance imaging. The imaging features and histology of each tumor were compared. Magnetic resonance imaging was very helpful in establishing a pathologic diagnosis. If a severe degree of involution was present, then the magnetic resonance findings could be ambiguous, making diagnosis more difficult.

Case report 871. Synovial sarcoma, monophasic type.

A patient with a synovial sarcoma of the foot and several unusual radiographic findings has been reported. Radiographs demonstrated lamellated periosteal reaction in a metatarsal, a rare finding in cases of synovial sarcoma. Magnetic resonance scanning documented marrow invasion of multiple bones in the foot, when bony involvement has been reported as only erosive changes.

Endothelin mobilizes calcium and enhances glucose uptake in cultured human skeletal myoblasts and L6 myotubes.

In this study we used endothelin as a paradigm to explore the concept that some vasoactive agents, acting through mobilization of Ca2+ and stimulation of protein kinase C, can interact with human skeletal muscle and modify its glucose transport. Cultured human skeletal myoblasts from the vastus lateralis demonstrated two subclasses of high-affinity endothelin receptors and a robust increase in cytosolic free Ca2+ upon exposure to endothelin. The endothelin-evoked rise in cytosolic free Ca2+ primarily resulted from Ca2+ mobilization from intracellular organelles. Both endothelin and insulin enhanced [3H]deoxy-D-glucose uptake in human myoblasts, but their effects were not additive. These findings also were observed in differentiated myotubes of L6 skeletal muscle cells. Moreover, [3H]deoxy-D-glucose uptake in human myoblasts was enhanced by treatment with phorbol 12-myristate 13-acetate. The endothelin- and insulin-mediated increases in [3H]deoxy-D-glucose were totally ablated by treatment with calphostin C. Such observations suggest that endothelin can enhance glucose uptake in human skeletal muscle. This is mediated through mechanisms that are at least partially protein kinase C dependent. Thus, increased levels of endothelin in vascular beds may contribute to altered glucose metabolism in essential hypertension.

A case report of intracortical hemangioma. A forgotten intracortical lesion.

The differential diagnosis for lytic intracortical lesions consists primarily of osteoid osteoma and Brodie's abscess. A third, less-well-known lesion is the intracortical hemangioma. It has an identical appearance to the two aforementioned lesions on bone scan and radiographs. This case report will describe the magnetic resonance imaging appearance of intracortical hemangioma and how it might be differentiated from osteoid osteoma and Brodie's abscess.

Resection arthrodesis of the knee for tumor: large intercalary allograft and long intramedullary nail technique.

Twenty-five patients had a procedure consisting of resection of the distal femur or proximal tibia for aggressive or malignant neoplasms. The resulting bony gap was bridged by allografts averaging 18 cm in length. Fixation was achieved using a long fluted intramedullary nail. The average follow-up time and time to union were 3 years (range, 0.25 to 9 years) and 13 months (range, 6 to 28 months), respectively. Eleven patients had nononcologic complications related to the index surgical procedure, including two patients with allograft nonunion. There were no infections. Three patients had amputations for local recurrence of their tumor. Twenty patients (80%) had no evidence of tumor at the time of follow-up. According to the Evaluation System of the Musculoskeletal Tumor Society, 80% of patients had a satisfactory result. No patient had a nononcologic complication resulting in total failure or amputation. The procedure of resection-arthrodesis of the knee using a large allograft with a long intramedullary nail provides patients with a stable, durable biological reconstruction that allows early weight-bearing, and the procedure carries a low incidence of infection.

Primary epiphyseal transplants and bone overgrowth in childhood amputations.

Seventeen children aged newborn to 14 years underwent major through-bone amputations or revision at our two institutions. Ten patients (group 1) had primary autogenous epiphyseal transplants taken from the amputated limb and used to cap the open medullary canal of the residual limb. Seven patients (group 2) did not have epiphyseal transplants. Nine of 10 patients in group 1 (90%) had no problems related to bone overgrowth or delay in prosthetic fitting. In group 2, six of seven patients (86%) had clinically symptomatic bony overgrowth of 20 months after the index amputation on the average. Four patients had surgical revisions. Therefore, provided healthy autogenous donor epiphyses are available, we recommend primary epiphyseal transplants to avoid the complications of bone overgrowth in childhood through-bone amputations.

Imaging rounds. Multifocal adamantinoma of the tibia and fibula.

The following is a description of the clinical and roentgenographic findings in a case exhibiting a condition of interest to the orthopaedic surgeon. Initial history, physical findings, and roentgenographic examinations are found on this page. The diagnosis and discussion of this case are presented on the following pages.