Sever's injury: a stress fracture of the immature calcaneal metaphysis.

Magnetic resonance imaging (MRI) in children with a presumptive diagnosis of Sever's apophysitis and with continuing pain after conservative treatment demonstrated bone bruising within the trabecular bone of the metaphyseal region adjacent to the calcaneal apophysis. Limited portions of the apophyseal secondary ossification center showed similar increased signal changes. MRI studies following treatment with immobilization showed subsidence or disappearance of the metaphyseal but not any apophyseal signal changes commensurate with improvement in symptoms. Accordingly, the disorder commonly referred to as Sever's ''apophysitis'' may be a metaphyseal trabecular stress fracture, similar to the toddler's calcaneal stress fracture that has minimal or no involvement of the apophyseal ossification center, and thus should not be referred to as an apophysitis. Rather, it appears to be an overuse injury causing microinjury within the developing metaphyseal "equivalent" trabecular bone that has not completely adapted to the changing biologic (biomechanical) requirements of the growing, athletically active child.

A review of rheumatoid arthritis affecting the foot and ankle.

Rheumatoid arthritis is a systemic disease that often affects the foot and ankle. Approximately 20% of patients with rheumatoid arthritis present initially with foot and ankle symptoms, and most patients will eventually develop foot and ankle symptoms. Although early intervention includes conservative measures, operative treatment often is needed to adequately treat rheumatoid patients. Treatment of foot and ankle problems in patients with rheumatoid arthritis is directed to maintaining ambulatory capacity. This article reviews the clinical presentation, evaluation, and treatment of rheumatoid arthritis affecting the foot and ankle.

Supracondylar femur fracture fixation: mechanical comparison of the 95 degrees condylar side plate and screw versus 95 degrees angled blade plate.

The best way to stabilize supracondylar femur fractures remains debatable. Previous studies have compared internal fixation to intramedullary fixation, but none have compared the stiffness characteristics and strength of the 95 degrees angled blade plate (ABP) with the 95 degrees condylar side plate and screw (DCS). 14 synthetic femora were cut in half and the proximal pole of the distal fragment was made secure. A 1 cm gap was made parallel to the femoral condylar weight-bearing surface to create an extraarticular supracondylar femur fracture (OTA 33-A3). 7 femora were stabilized with an ABP and 7 with a DCS. Using an MTS compression/torsion servohydraulic testing machine, each femur was tested in 7 modes of loading: (1) axial compression; (2) anterior compression; (3) posterior compression; (4) medial compression; (5) lateral compression; (6) torsion in external rotation; and (7) torsion in internal rotation. The stiffness of the construct in each mode, the "maximum load in axial compression", and the fatigue characteristics in axial compression were measured. The DCS showed a statistically significant greater stiffness in axial compression and average maximal load than the ABP. The fatigue tests revealed no evidence of permanent deformation or loosening of either construct.