The Use of Proximal Femur Replacement for the Management of Oncologic Lesions in the Proximal Femur: A Review.

With improved chemotherapeutic treatment, patients with primary or metastatic bone tumor have improved prognoses and longer life expectancies; therefore, durable limb-salvage constructs are critical. For tumors of the proximal femur, endoprosthetic replacement is an option for treatment in primary and metastatic disease, with the goals being tumor and pain control, earlier mobilization, shorter recovery period, and, in primary tumors, cure. This study provides a summary of current concepts in the treatment of oncologic lesions in the proximal femur with endoprostheses. Discussion of the inherent complications of these constructs is presented as well as the risks and treatment of reconstruction failure.

Argon beam coagulation as adjuvant treatment after curettage of aneurysmal bone cysts: a preliminary study.

UNLABELLED: The optimal treatment of aneurysmal bone cysts remains an area of debate. Curettage, with or without adjuvant therapy, has been advocated for tumors in most locations. To evaluate argon beam coagulation as adjuvant therapy to curettage, we retrospectively analyzed the complication and recurrence rates in 40 consecutive patients with a diagnosis of aneurysmal bone cyst. For our analysis of recurrence, we excluded six of the 40 patients who were lost to followup or had less than 18 months followup; five patients treated with resection also were excluded. Of the remaining 29 patients, 17 were treated with curettage and argon beam coagulation and 12 were treated with curettage with or without phenol. None of the 17 patients treated with curettage and argon beam coagulation had a recurrence, whereas four patients treated without argon beam coagulation had recurrences. There were no differences between patients treated with or without argon beam coagulation regarding frequencies of intraoperative complications, neurovascular injury, or bone graft incorporation. Argon beam coagulation seems to offer favorable control rates when compared with curettage with or without phenol. No complications have been experienced thus far with its use. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Histologic evaluation of the depth of necrosis produced by argon beam coagulation: implications for use as adjuvant treatment of bone tumors.

Argon beam coagulation (ABC) has been advocated as adjuvant treatment after curettage of aggressive benign bone tumors. This study was done to evaluate the depth of necrosis in cancellous bone treated with ABC. A 6-month-old pig was sacrificed and 20 1.5-cm cortical windows were created in the metaphyseal areas of the humeri, femora, and tibiae, exposing the underlying cancellous bone. The defects were randomly assigned to four groups: A, control; B, ABC at 50 W; C, 100 W; and D, 150 W. Histologic evaluation determined the depth of necrosis at each setting: A, 0.1 +/- 0.1 mm; B, 1.0 +/- 0.5 mm; C, 2.9 +/- 1.0 mm; and D, 4.2 +/- 0.7 mm. There were statistically significant differences between each of the experimental groups and the control (p < .0001), between groups B and C (p < .0001), and groups C and D (p = .0002).

Progressive valgus deformity after curettage of benign lesions of the proximal tibia.

BACKGROUND: Progressive valgus deformity after proximal tibial metaphyseal fractures in pediatric patients has been well described, although the pathophysiology is not clear. We performed a retrospective study to evaluate the occurrence of progressive tibia valga after curettage of benign bone lesions of the tibia. METHODS: During a 6-year period, we performed curettage and bone grafting of benign bone lesions of the tibia in 20 patients aged 16 years and younger. Radiographs and clinical notes were reviewed. The diagnosis, age, sex, location of lesion, surgical approach, physeal arrest, limb-length discrepancy, deformity, and treatment were documented. RESULTS: Four patients subsequently developed progressive tibia valga (mean, 12 degrees; range, 7-21 degrees). Progressive valgus deformity occurred in 4 of 5 patients younger than 10 years old who had curettage of lesions of the proximal tibial metaphysis. Deformity did not occur in any of the 13 patients older than 10 years (range, 13-16 years) or in any of the 8 patients who had curettage of the distal tibia (age range, 6-14 years). In patients who developed tibia valga, the deformity progressed during the first 6 to 17 months postoperatively and then stabilized. One patient required corrective osteotomy at age 12 years for a symptomatic 21-degree deformity 3 years after curettage. The other 3 patients with tibia valga remained asymptomatic and demonstrated partial correction of their deformities, currently ranging from 3 to 7 degrees with a mean follow-up of 31 months (range, 19-47 months). CONCLUSIONS: Progressive tibia valga seem to be relatively common in patients younger than 10 years who have had curettage of the proximal tibial metaphysis. This potential sequela should be discussed thoroughly with the patient's parents before proceeding with surgery, and patients should be followed and evaluated for this postoperatively.

Reconstruction of noncontained distal femoral defects with polymethylmethacrylate and crossed-screw augmentation: a biomechanical study.

BACKGROUND: Curettage and cementation with polymethylmethacrylate are frequently used in the treatment of aggressive benign bone lesions such as giant-cell tumors, but strength and stiffness of the reconstructed bone have been concerns. This biomechanical study was undertaken to determine whether augmenting the cement with crossed screws would result in a stronger reconstruction. METHODS: Large noncontained defects were created in the medial femoral condyles of twenty matched pairs of human cadavera. Four groups were organized to compare three types of reconstruction: (1) polymethylmethacrylate alone, (2) polymethylmethacrylate and intramedullary Steinmann pins, and (3) polymethylmethacrylate with crossed screws engaging the opposite cortex. The specimens were subjected to 2000 compressive cycles and were subsequently monotonically loaded to failure under a controlled displacement rate. Failure load and stiffness were determined for each femur that survived the cycling process. RESULTS: Femora reconstructed with crossed screws and cement failed at higher loads and had greater stiffness than those reconstructed with cement alone (p = 0.025 and p = 0.0007) or cement augmented with intramedullary Steinmann pins (p = 0.019). Failure of femora reconstructed with cement and crossed screws occurred through an extra-articular transverse fracture, while failure in those with cement alone and cement with Steinmann pins occurred through an intra-articular (intercondylar) fracture. CONCLUSIONS: In this in vitro cadaver study, augmentation of polymethylmethacrylate cement with crossed screws resulted in a stronger reconstruction of distal femoral tumor defects than that obtained with cement alone or with cement and intramedullary Steinmann pins.

Pathological fracture in acute osteomyelitis of long bones secondary to community-acquired methicillin-resistant Staphylococcus aureus: two cases and review of the literature.

Pathologic fracture is a rare complication of acute bacterial osteomyelitis in adults. Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) has been increasingly reported in skin and soft tissue and systemic infections in children and adults, including many cases of osteomyelitis. We recently treated two adult patients with acute osteomyelitis of long bones secondary to CA-MRSA complicated by a pathologic fracture. In both patients, the primary source of dissemination to the bone was a skin and soft tissue infection. We speculate that virulence factors specific for CA-MRSA currently circulating in the United States may predispose to a complicated course of acute osteomyelitis.

Distal Femoral Replacement for Acute Distal Femoral Fractures in Elderly Patients.

OBJECTIVES: To evaluate outcomes and complications using cemented modular distal femoral replacement in elderly patients with distal femoral fractures. DESIGN: Retrospective chart review, case series. SETTING: A Level 1 and Level 2 trauma center, both tertiary referral hospitals. PATIENTS/PARTICIPANTS: Eighteen patients older than 60 years (average age 77 years) who had cemented distal femoral replacement for distal femoral fractures (comminuted, intraarticular, osteoporotic, arthritic) between 2005 and 2013. Patients with previous knee surgery were excluded. INTERVENTION: Cemented modular distal femoral replacement. MAIN OUTCOME MEASURES: Implant status, complications, Knee Society Score, Musculoskeletal Tumor Society score, and Western Ontario and McMaster Osteoarthritis Index. RESULTS: All patients were extremely or very satisfied with their outcomes. For patients with functional outcome data, Knee Society Score averaged 85.7 with a functional score of 35, Musculoskeletal Tumor Society score averaged 19.2, and Western Ontario and McMaster Osteoarthritis Index score averaged 23.1 at an average follow-up of 2.3 years. Range of motion was 1-99 degrees. Implant-related complications occurred in 2 patients (11%); one required revision to total femoral replacement because of periprosthetic fracture and the other had a deep infection that required exchange of the components. No patient had aseptic loosening or patellar maltracking. There were no perioperative deaths or late amputations. CONCLUSIONS: Cemented modular distal femoral replacement is a viable treatment option in elderly patients that permits immediate full weight-bearing, with most patients returning to preoperative functional status. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Blastomycosis: Case report of an isolated lesion in the distal fibula.

Blastomycosis (Blastomyces dermatitidis) is a fungal infection that occurs primarily in the lungs, but 15% to 60% of patients with systemic blastomycosis have skeletal involvement. Because the symptoms and radiographic appearance of bony lesions are variable, diagnosis and treatment may be delayed if fungal infections are not included in the differential diagnosis for a patient with a lytic bone lesion. We present the case of a man in his late 30s with no local or systemic signs of infection in whom biopsy-curettage of a painful ankle lesion identified budding yeast consistent with North American blastomycosis. After treatment with itraconazole, the patient was symptom-free and had returned to his previous activities without pain or difficulty.

Reconstruction of noncontained proximal tibial defects with divergent screws and cement.

Postoperative fracture is a well described complication following curettage and cementation of aggressive benign bone tumors. We asked whether: (1) the addition of diverging screws that engage the opposite cortex increase the strength and rigidity of the construct in the proximal tibia compared with (a) cement alone and (b) would cement with intramedullary Steinmann pins; and (2) the modes of failure be different for those constructs. The average load to failure for tibias reconstructed with cement augmented with diverging screws (6321 +/- 681 N) was higher than for tibias reconstructed with cement alone (2343 +/- 222 N). The average load to failure for tibias reconstructed with cement augmented with diverging screws (6885 +/- 445 N) was higher than for tibias reconstructed with cement and intramedullary Steinmann pins (5218 +/- 941 N). Furthermore, constructs with cement augmented with diverging screws were less likely to fail by an intraarticular fracture than other types of constructs. Our data support the use of diverging screws that engage the opposite cortex to augment the strength of the construct when using acrylic cement to fill noncontained defects after curettage of the proximal tibia. This more stable, stronger construct might allow earlier mobilization and rehabilitation after curettage, with a decreased risk of fracture.

Imaging of bone sarcomas.

Identification, staging, and treatment of bone sarcomas rely on both clinical and imaging evaluations. Although conventional radiography remains the primary imaging modality for characterizing bone tumors, bone scintigraphy, computed tomography, magnetic resonance imaging, and positron emission tomography can each add information for staging and treatment planning.

Errors in the MRI evaluation of musculoskeletal tumors and tumorlike lesions.

Interpretation of an MRI of a suspected musculoskeletal neoplasm can be extremely difficult. Fifty-six MRIs originally evaluated by outside radiologists were independently evaluated by an expert panel consisting of three specialized musculoskeletal radiologists. The outside reports were then graded based upon accuracy and completeness of the differential diagnosis. We compared the expert opinions with those of the outside radiologists. According to the expert panel, only 30 of the 56 (54%) outside reports listed the most likely diagnosis as such and only 35 (63%) listed it at all. A complete appropriate differential diagnosis was listed in only 22 (39%) of the outside reports. Furthermore, 18 (32%) of the outside reports listed diagnoses judged to be extremely unlikely by the experts. In a subset of 15 patients with images that the expert panel had judged diagnostic of specific entities, only nine of the outside reports listed the correct diagnosis as such and only 10 listed it at all. Furthermore, 11 (73%) of the outside reports listed extremely unlikely possibilities for these diagnostic images. We found a substantial difference between the expert and the outside opinions.

Telangiectatic osteosarcoma: the St. Jude Children's Research Hospital's experience.

BACKGROUND: Telangiectatic osteosarcoma (TOS) is a rare subtype of osteosarcoma (OS). The authors reviewed their experience with TOS to characterize its histologic, radiologic, and clinical features. METHODS: The authors reviewed records, pathology material, and imaging studies from all patients with TOS who were treated between 1978 and 2005 and compared their outcomes with the outcomes of patients with all other subtypes of high-grade osteosarcoma (OS). RESULTS: Among 323 patients with OS, 22 patients (6.8%) had TOS. Two additional patients who were treated in Chile on a recent OS trial were included. The median age at diagnosis of the 24 patients was 15.7 years. Four patients (17%) had metastatic disease, and 9 of 21 patients (43%) had pathologic fractures. Only 5 patients (who were treated after 1994) underwent limb-salvage surgery. Estimates of 5-year event-free survival (58.3% +/- 11.9%) and overall survival (66.8% +/- 11.6%) were similar to those for patients with other OS subtypes (P > or = .85). The absence of local disease progression and chemotherapy with > or =3 agents that were active against OS were correlated with improved outcome (P < or = .005). The presence of a pathologic fracture was not associated with surgery type or patient outcome. CONCLUSIONS: TOS was associated with a high rate of pathologic fracture. With multimodality therapy, the outcome of patients with TOS was similar to that of patients with other high-grade OS subtypes. The absence of local disease progression and chemotherapy with > or =3 active agents were associated with a favorable outcome.

Staging of primary malignancies of bone.

Staging of bone sarcomas is the process whereby patients are evaluated with regard to histology, as well as the local and distant extent, of disease. Bone sarcomas are staged based on grade, size, and the presence and location of metastases. The system is designed to help stratify patients according to known risk factors. Proper staging helps define the prognosis for patients and helps guide their treatment. Furthermore, staging allows meaningful comparisons to be done among groups of patients.

A comparison study of staging systems for bone sarcomas.

A retrospective study of 250 patients treated at one institution was done to evaluate the prognostic significance of the new American Joint Committee on Cancer staging system compared with the Musculoskeletal Tumor Society staging system for patients with sarcomas of bone. Regarding the Musculoskeletal Tumor Society system, there were significant differences in survival among patients with Stage I, Stage II, and Stage III disease. There were no significant differences between patients with Stages I-A and I-B disease, nor between patients with Stages II-A and II-B disease. Similarly, regarding the new American Joint Committee on Cancer staging system, there were significant differences among patients with Stage I, Stage II, and Stage IV disease. No significant differences were seen between patients with Stages I-A and I-B disease, between patients with Stages II-A and II-B disease, nor between patients with Stages IV-A and IV-B disease. A significant advantage in the ability to predict prognosis for one staging system over the other staging system was not shown with the relatively small number of patients in this study.

The incidence and prognosis of osteosarcoma skip metastases.

The poor prognosis for patients with osteosarcoma skip metastases has been established in the literature; however, most of the data in the literature concerning osteosarcoma skip metastases were collected before routine use of magnetic resonance imaging and before the use of modern multiagent chemotherapy regimens. This retrospective multiinstitutional study was done to evaluate the efficacy of magnetic resonance imaging to detect skip metastases and to evaluate the prognosis for these patients when treated with modern multiagent chemotherapy protocols. In a group of 155 patients who were younger than 26 years when diagnosed and treated for high-grade osteosarcoma of the long bones, 10 (6.5%) patients with skip metastases were identified. Eight of the 10 lesions were detected on pretreatment magnetic resonance imaging scans and two were detected only from the surgical pathology specimens. Five patients had concomitant pulmonary metastases at presentation and five patients had no other known site of diseases. All 10 patients died, with an average survival of 32.5 months (range 11-71 months). The five patients with only skip metastases at presentation survived an average of 27.2 months (range 15-44 months). Despite advances in the treatment of patients with osteosarcomas, those with skip metastases continue to have a poor prognosis, and they should be counseled regarding the limitations of current therapies.