Inter- and intraobserver reliability assessment of the Cobb angle: manual versus digital measurement tools.

The objective of this study is to determine the intraobserver and interobserver reliability of end vertebra definition and Cobb angle measurement using printed and digital radiographs of 48 patients with scoliosis. The Cobb angle and the end vertebra were assessed by six observers in 48 patients with scoliosis using printed and digital radiographs. Definition of end vertebra and measurement of the Cobb angle was repeated three times with a 3 week interval. Intraclass correlation coefficients (ICC) were used to determine the interobserver and intraobserver reliabilities. 95% prediction limits for the errors in measurements are provided. For the Cobb angle a mean ICC of 0.97 was determined for intra- and interobserver reliability measurement of the printed radiographs. For the electronic radiographs a mean ICC value of 0.93 was determined for interobserver reliability and a mean ICC value of 0.96 for intraobserver reliability. Intraobserver ICC for definition of end vertebrae was 0.8 for both methods. Interobserver ICC was 0.83 for the manual and 0.74 in the digital method. One pitfall in angle measurement implies the Cobb method itself which measures in two dimensions. Until we develop a proper tri-dimensional measuring system an error is introduced. For the Cobb angle measurement the definition of end vertebrae introduces the main source of error. Digital radiography does not improve the measurement accuracy.

High recurrence after calf lengthening with the Ilizarov apparatus for treatment of spastic equinus foot deformity.

Both gastrocnemius recession and Achilles tendon lengthening lead to scarring in the calf and have high reported recurrence rates when performed under the age of 8 years. Triceps surae lengthening by external fixation seemed to be a valuable alternative. Twelve calf lengthenings have been performed with an Ilizarov device with a mean correction of 27 degrees. No calcaneal gait was observed, but there was a slow continuous loss of dorsiflexion over the observation period. The Ilizarov technique has a higher recurrence rate than most operative procedures for calf lengthening, but carries virtually no risk in producing calcaneus. The technique cannot be recommended for routine clinical use and may only be an alternative for selected cases.

Significance of talar distortion for ankle mobility in idiopathic clubfoot.

The abnormal bony feature found most consistently in clubfeet is talar distortion. The significance of the talar distortion for mobility of the tibiotalar joint was investigated. Twenty-seven congenital clubfeet in 19 patients were examined at a minimal followup of 20 years. In all patients Turco's posteromedial release was done because of idiopathic clubfoot. Radiographic assessment of the feet included measurement of the talocalcaneal angle and index, and the tibiocalcaneal angle. The degree of talar flattening was estimated by the ratio of the curvature of the talar dome to the length of the talar bone (radius to length ratio). Three-dimensional gait analysis was done to assess the dynamic range of ankle motion. The static range of motion was measured with a goniometer. The degree of talar flattening correlated significantly with the dynamic range of ankle motion but not with the static mobility. For assessment of idiopathic clubfoot, evaluation of talar flattening should be done because of its significance for dynamic ankle mobility.