Refracture of adolescent femoral shaft fractures: a complication of external fixation. A report of two cases.

Malunion is often a problem in adolescent femoral shaft fractures treated with traction and subsequent casting. We used external fixation as an alternative treatment method to control alignment and allow early mobilization. After fracture healing and fixator removal, two patients experienced refracture. This unusual complication is the basis of our report. Prolonged rigid or static fixation appears to be detrimental to sufficient callus formation and healing.

The effects of contact pressure elevations and aseptic necrosis on the long-term outcome of congenital hip dislocation.

The relationship between excessive articular contact pressure, aseptic necrosis, and the long-term outcome with unilateral congenital dislocation of the hip (CDH) was studied in a series of 84 patients treated by closed reduction and followed for an average of 29.2 years. Contact stress was estimated from archived radiographs taken at the time of maturity and at several follow-up visits. At a recent review, each patient was rated both clinically for pain and function and radiographically for deformity, degeneration, and aseptic necrosis. For each of 431 archived films, articular contact stress (force/area) was estimated mathematically, based upon a frontal plane equilibrium (force) analysis and a landmark-based inference of three-dimensional head surface (area). Good correlation with final deformity (Spearman rho = 0.78) was obtained when the hips were ranked in terms of a new cumulative overpressure index Pc, defined as a time-pressure product involving years of pressure exposure beyond a 2 MPa pressure damage level. An unsatisfactory outcome occurred in 90.4% of the hips experiencing Pc greater than 10 MPa-years (most of which had aseptic necrosis involvement), whereas the outcome was satisfactory in 80.9% of hips with Pc less than 10 MPa-years.

Demonstration of tissue-specific antigens shared by normal pancreas and pancreatic neoplasms.

Xenoantiserum raised against extracts of normal hamster pancreas, after absorption with normal tissues, reacted specifically with normal hamster and human pancreas by immunodiffusion. Absorbed antiserum also reacted with hamster and human pancreatic carcinoma but not with other neoplasms. Immunization of hamsters with normal pancreas extracts prevented growth of transplantable pancreatic carcinomas.