Patellar tendon shortening surgery restores the knee extensor mechanism in flexed knee gait in children with cerebral palsy.

Background: This study evaluated a patellar tendon shortening (PTS) surgical procedure that uses an overlapping repair combined with an additional Tycron non-absorbable suture to support the shortening in children with Cerebral Palsy (CP). This study aimed to outline this surgical technique and to evaluate its effectiveness in restoring the knee extensor mechanism.

Methods: The sagittal plane lower limb kinematics, peak knee extensor moment, gait deviation index (GDI), localised movement deviation profile (MDP), temporospatial parameters, passive knee extension ROM, quadriceps lag, and knee extensor strength were calculated pre- and postoperatively.

Comprehensive non-dimensional normalization of gait data.

Normalizing clinical gait analysis data is required to remove variability due to physical characteristics such as leg length and weight. This is particularly important for children where both are associated with age. In most clinical centres conventional normalization (by mass only) is used whereas there is a stronger biomechanical argument for non-dimensional normalization.

The comparison of normative reference data from different gait analysis services.

Comparison of normative data between gait analysis services offers the potential to harmonise data collection protocols. This paper presents a method for such a comparison based on an assumption that the root mean square difference from the inter-service mean is a reflection of systematic differences in protocols and that the average standard deviation includes a component attributable to within-centre measurement variability. Substantial normative datasets from two highly respected clinical services were compared.