We undertook a randomised clinical trial to compare
treatment times and failure rates between above- and below-knee
Ponseti casting groups. Eligible children with idiopathic clubfoot,
treated using the Ponseti method, were randomised to either below-
or above-knee plaster of Paris casting. Outcome measures were total
treatment time and the occurrence of failure, defined as two slippages
or a treatment time above eight weeks. A total of 26 children (33 feet) were entered into the trial.
The above-knee group comprised 17 feet in 13 children (ten boys
and three girls, median age 13 days (1 to 40)) and the below-knee
group comprised 16 feet in 13 children (ten boys and three girls,
median age 13 days (5 to 20)). Because of six failures (37.5%) in
the below-knee group, the trial was stopped early for ethical reasons.
The rate of failure was significantly higher in the below-knee group
(p = 0.039). The median treatment times of six weeks in the below-knee
and four weeks in the above-knee group differed significantly (p
= 0.01). This study demonstrates that the use of a below-knee plaster
of Paris cast in conjunction with the Ponseti technique leads to
unacceptably high failure rates and significantly longer treatment
times. Therefore, this technique is not recommended. Cite this article:
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.
