Bone metastases from squamous cell carcinoma of the head and neck.

BACKGROUND AND OBJECTIVES: Carcinoma of the head and neck is an uncommon primary source of bone metastases. The increasing duration of survival of these patients, however, increases the probability of late bone involvement. The objective was to identify the frequency, clinical presentation, and clinical course of metastatic disease to bone from head and neck primaries. METHODS: A retrospective review was accomplished of the radiographs and nuclear medicine studies for 363 cases of squamous cell carcinoma of the head and neck for whom radiologic studies had been performed. For those with identified bone involvement, a chart review was performed to identify clinical presentation, disease course, and outcome. RESULTS: Only approximately 1% of these patients had clinically demonstrable bone metastases. Eight sites of bone involvement were identified in five patients, including three pelvic, two femoral, and one each humeral, rib, and thoracic spine lesions. All lesions were purely lytic with moth-eaten or permeative borders. Time from primary tumor diagnosis to identification of metastatic disease ranged from being present at diagnosis to a maximum 3.5 years later. Time from identification of metastatic disease to patient death was no greater than 8 months. CONCLUSIONS: Despite the increasing overall survival of patients with these carcinomas, distant bone metastases are infrequent, but should be considered a possibility in any patient with a concurrent or past diagnosis of head and neck carcinoma. The very short time from discovery of bone dissemination to death in most of these patients should be taken into consideration when contemplating operative intervention.

Intramedullary screw fixation of Jones fractures: a biomechanical study.

The management of proximal fifth metatarsal ("Jones") fractures in athletes has become increasingly more aggressive, despite a lack of biomechanical data in the literature. A cadaver biomechanical study was conducted to evaluate the strength of intramedullary fixation of simulated Jones fractures loaded to failure via three-point bending on a Materials Testing System machine. In a series of eight intact fifth metatarsal control specimens, the force to failure (fracture) was measured for comparison with repaired specimens. Acute fractures were simulated in 10 pairs of feet via osteotomy at the typical fracture location and were fixed with either a 4.5-mm malleolar screw or a 4.5-mm partially threaded, cancellous, cannulated screw, both placed using conventional intramedullary techniques. Force at initial displacement averaged 73.9 N (SD, 64.7 N) for the malleolar screws and 72.5 N (SD, 42.3 N) for the cannulated screws. Force at complete displacement averaged 519.3 N (SD, 226.2 N) for the malleolar screws and 608.4 N (SD, 179.7 N) for the cannulated screws. The force to failure of the intact specimens was significantly greater than the initial and complete forces to failure for the fixed specimens (P < 0.05, independent measures analysis of variance). There was no statistical difference between the average forces at initial displacement or at complete displacement in the fixed metatarsal specimens for the two different types of screws, but the forces at complete displacement for each screw type were significantly greater than the forces at initial displacement (P < 0.05). On the basis of literature review and data generated from this study, it is apparent that the forces necessary to cause displacement of the stabilized Jones fracture are above what would be transmitted within the lateral midfoot during normal weightbearing. The choice of screw and intramedullary technique of fixation is a matter of surgeon preference, because the choice of screw makes no biomechanical difference.