Adult human cadaver pelves were tested to determine micromotion at the prosthesis-bone interface in cementless hemispherical acetabular components during simulated single-limb stance. The micromotion of non-press-fit components with screw fixation in response to cyclic loads to a maximum of 1500N was compressive (interface closing) at the superior iliac rim and distractive (interface opening) at the inferior ischial rim; that of press-fit components was compressive all around the acetabular rim regardless of screw fixation. Adding screws to the component decreased the micromotion at the site of the screw, but sometimes increased it at the opposite side. Two dome screws with the press-fit component decreased the micromotion at the superior iliac rim but at the inferior ischial rim there was either no change or increased movement. A press-fit cup shows less micromotion than a non-press-fit cup with screw fixation. The addition of screws to a press-fit cup does not necessarily increase the initial stability.

The results of immediate plate fixation of 97 open fractures of the tibial shaft in 95 patients are reported. Significant joint stiffness occurred in 11.4% and angular malunion of greater than 5 degrees in any plane was seen in 3.1%. The infection rate was 10.3%. However, even in those cases which develop delayed union or other complications, plate fixation of open fractures can produce excellent recovery of limb function.

The results of the use of Harrington rods in the treatment of spinal fractures were reviewed. It was found that with burst fractures where the anterior pillar was deficient there was a significant incidence of loss of reduction. Anterior bone supplementation is recommended in these fractures when major loss of height or angulation occurs. Several technical faults were detected which, in most cases, also led to a loss of reduction. Almost all patients with an anatomical reduction were free of pain. There was no correlation between the loss of reduction and the lapse of time before operation, the levels of instrumentation, the length of the fusion, the severity of the initial deformity, the degree of initial correction or the presence or absence of a neurological deficit.