Bone cements produced by different manufacturers vary in their mechanical properties and antibiotic elution characteristics. Small changes in the formulation of a bone cement, which may not be apparent to surgeons, can also affect these properties. The supplier of Palacos bone cement with added gentamicin changed in 2005. We carried out a study to examine the mechanical characteristics and antibiotic elution of Schering-Plough Palacos, Heraeus Palacos and Depuy CMW Smartset bone cements.

Both Heraeus Palacos and Smartset bone cements performed significantly better than Schering-Plough Palacos in terms of mechanical characteristics, with and without additional vancomycin (p < 0.001). All cements show a deterioration in flexural strength with increasing addition of vancomycin, albeit staying above ISO minimum levels. Both Heraeus Palacos and Smartset elute significantly more gentamicin cumulatively than Schering-Plough Palacos. Smartset elutes significantly more vancomycin cumulatively than Heraeus Palacos.

The improved antibiotic elution characteristics of Smartset and Heraeus Palacos are not associated with a deterioration in mechanical properties. Although marketed as the ‘original’ Palacos, Heraeus Palacos has significantly altered mechanical and antibiotic elution characteristics compared with the most commonly-used previous version.

Sickle-cell disease (SCD) is probably the commonest cause of avascular necrosis worldwide, and its prevalence appears to be rising in developed countries. Avascular necrosis of the humeral head is a common complication but has not been previously studied in detail. We have reviewed 138 patients with SCD for clinical, radiological and functional abnormalities of the shoulder, using a radiological classification designed for avascular necrosis of the shoulder. Radiographic lesions, frequently bilateral, were found in 28% and only 53% of patients had normal shoulder function. The management of this relatively common complication is difficult. Joint replacement is likely to fail and early diagnosis is important.

We report five patients with tibia vara due to focal fibrocartilaginous dysplasia of the medial aspect of the proximal tibia. In three patients spontaneous correction occurred, while in one of the remaining two treated by operation, a valgus deformity and neurological complications resulted. Conservative management is therefore recommended.

Ten children who had clinically stable hips at birth were radiographed at one month because they had factors predisposing to hip dislocation. In all cases one or both hips gave rise to a suspicion of dysplasia, though clinical abnormalities were slow to appear. Four of these hips subsequently dislocated. We believe that infants with late presentation of acetabular dysplasia and clinical abnormality belong to a different aetiological group from those with neonatal instability due to ligamentous laxity. The significance of this differentiation is that some infants presenting late have only recently dislocated, and the diagnosis has not necessarily been "missed" at neonatal examination.