Faculty Bibliography

Although functionally appealing in preserving the native knee, the condyle-sparing intercalary allograft of the distal femur may be associated with a higher risk of tumor recurrence and endoprosthetic replacement for malignant distal femoral bone tumors. We therefore compared the risk of local tumor recurrence between patients in these two types of reconstruction groups. We retrospectively reviewed 85 patients (mean age, 22 years; range, 4-82 years), 38 (45%) of whom had a condyle-sparing allograft and 47 (55%) of whom had endoprostheses. The minimum followup for both groups was 2 years (mean, 7 years; range, 2-19 years). Local recurrences occurred in 11% (five of 47) of the patients having implants versus 18% (seven of 38) of the patients having allografts. Using time to local recurrence as an end point, the Kaplan-Meier survivorship of the implant group was similar to that of the condyle-sparing allograft group at 2, 5, and 10 years (93% versus 87% at 2 years, 87% versus 81% at 5 years, and 87% versus 81% at 10 years, respectively). The condyle-sparing allograft procedure offers the potential advantage of retaining the native knee in a young patient population while incurring no greater risk of local recurrence as those offered the endoprosthetic procedure. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence

The introduction of the hospitalist co-management model represents an opportunity to improve care by changing the system as it applies to a small group of patients. Eighty-six consecutive patients with multiple comorbidities were selectively enrolled in an academic medical center hospitalist-orthopedic surgery co-management patient care program. Patients were stratified by all patient refined diagnosis-related groups, severity of illness, and risk of mortality. Hospital length of stay, cost of care, in-hospital mortality, complications, and intensive care unit admissions were compared with a retrospectively constructed control group of 54 patients undergoing similar surgery during the period immediately preceding initiation of the program. The University Health System Consortium observed-to-expected ratio for hospital length of stay was 0.693 compared to 0.862 for the control group. The severity of illness and risk of mortality scores represented a relatively higher risk stratification in the study group. While the overall observed-to-expected cost of care remained virtually unchanged, the positive impact of the study model revealed an increased positive effect on the more severely affected severity of illness and risk of mortality patients. The results of this study suggest that a proactive, cooperative, co-management model for the perioperative management of high-risk patients undergoing complex surgery can improve the quality and efficiency metrics associated with the delivery of service to patients

Enhance your diagnostic skills with this 'test yourself' monthly column, which features a radiograph and challenges you to make a diagnosis

Giant-cell tumor is a benign but locally aggressive primary bone tumor that requires surgical management. Most giant-cell tumors initially are demonstrated on radiographs as distal, subarticular, geographic osteolytic lesions. Abundant giant cells on histology are reactive secondary to a neoplastic fibroblast-like stromal cell. Giant cells are present in many neoplastic and non-neoplastic bone lesions; therefore the diagnosis of giant-cell tumors requires correlation of clinical, imaging, and pathologic data to exclude other lesions that demonstrate a similar histologic pattern. A small number of giant-cell tumors result in lung lesions, many of which have benign histology, can be treated by wedge resection, and do not affect long-term outcome. After adequate surgical curettage and the use of intraoperative surgical adjuvants, recurrence rates of approximately 10% are reported

The etiology of aneurysmal bone cysts is uncertain, but they may originate as a localized arteriovenous malformation. These benign lesions can be primary or occur secondary to an underlying lesion. The majority of patients who present with aneurysmal bone cysts are younger than age 20 years. One half of lesions occur within the long bones and one third involve the spine. Most flat bone lesions, approximately 10%, occur in the pelvis. Fluid-fluid levels are common on CT and MRI but are not pathognomonic. Although aneurysmal bone cyst is benign, there may be aggressive clinical and imaging features. Treatment for aneurysmal bone cyst is surgical curettage, intraoperative adjuvant therapy, and bone grafting of the lesion. The prognosis following treatment is very good, although 10% to 20% of cases are reported to recur

Human myxoid liposarcoma contains a characteristic t(12;16) chromosomal translocation that results in fusion of the N-terminal domain of the translocated in liposarcoma (TLS) protein to the C/EBP homologous protein (CHOP). TLS possesses structural motifs that suggest it may participate in RNA processing. We demonstrate that in human myxoid liposarcoma cells, wild-type TLS binds to RNA polymerase II (Pol II) via its N-terminal domain and to the transcription and translation factor Y-box binding protein-1 (YB-1) through its C-terminal domain. The liposarcoma fusion protein TLS/CHOP retains the ability to bind RNA Pol II but lacks the ability to recruit YB-1 due to replacement of the C-terminal domain of TLS by CHOP. In an in vivo splicing assay, YB-1 promotes splicing of adenovirus EIA pre-mRNA predominantly to the 13S isoform. The oncogenic TLS/CHOP fusion protein inhibits this splicing function of YB-1 in a dominant negative manner. When considered in conjunction with studies on other sarcoma fusion proteins, these data suggest that aberrant RNA splicing may be a common feature of human sarcomas

STUDY DESIGN: A retrospective review of elderly patients treated without surgery for chronic mobile nonunions of the odontoid process. Patients were observed on an annual basis with clinical examinations and flexion/extensions plain film radiographs. OBJECTIVES: To evaluate the clinical and radiographic results of elderly patients without myelopathy treated without surgery for dens fracture nonunion. SUMMARY OF BACKGROUND DATA: Because of the risk of progressive myelopathy or sudden neurologic injury, many surgeons recommend operative stabilization for patients with mobile dens nonunions who are able to withstand an operation. There is, however, a lack of information about the radiographic and neurologic progression of dens nonunions. Although a less aggressive surgical approach has been recommended by some authors for elderly or medically compromised patients with acute fractures, long-term follow-up evaluation of patients with resulting nonunions has not been reported. METHODS: A series of elderly patients with chronic, unstable, dens nonunions without myelopathy were treated with a nonoperative treatment protocol. Patients were informed of the nature of their lesion, including the risk of acute or chronic spinal cord injury and the options for operative treatment. Patients were evaluated yearly for clinical and radiographic progression. No intervention to slow progression of atlantoaxial instability was undertaken. RESULTS: None of the patients developed myelopathic symptoms during the follow-up period, and no patient experienced more than a 1 mm radiographic increase in atlantoaxial excursion. None of the reported patients had less than 14 mm available for the spinal cord in either flexion or extension at the start of clinical monitoring. CONCLUSIONS: Although further follow-up evaluation is needed, the authors believe on the basis of this review that this treatment protocol may be considered for patients who are poor candidates for surgical fusion