Using Tibialis Anterior Shortening (TATS) in combination with Achilles Tendon Lengthening (TAL) to treat spastic equinus in children with cerebral palsy (CP) was described in 2011. Short-term results have indicated a good outcome, especially an improvement of the drop foot in swing phase and the correction of equinus in stance phase. The aim of this study was to analyse the results of the long-term follow-up and to determine the relapse rate of TATS and TAL. The kinematics of the sagittal, frontal and transversal planes were measured by using instrumented 3D gait analysis at three defined time points and then described using the Gait Profile Score (GPS) and Movement Analysis Profile (MAP). The data was exported into Gaitabase and then the preoperative (T0), short- term (T1) and long-term (T2) follow-up data was statistically compared. 23 patients (mean age at index-surgery=14.9years) were included, there was a mean follow-up time of 5.8 years. 3 children (13%) have shown a relapse. The data of 12 children with spastic hemiplegia (12 legs), as well as 8 children with spastic diplegia (10 legs) has been analysed. There has been a significant (p<0.05) improvement in GPS and MAP for ankle dorsiflexion (describes equinus and drop foot) of the operated legs versus not operated legs. TATS in combination with TAL shows a satisfactory long-term result after 5.8 years in the correction of fixed equinus and drop foot in children with CP. Postoperatively all subjects were able to walk without an AFO.