Stability of the Gross Motor Function Classification System after single‐event multilevel surgery in children with cerebral palsy

Abstract

There are conflicting reports about the stability of the Gross Motor Function Classification System (GMFCS) in children with cerebral palsy (CP) after orthopaedic surgery. We studied the stability of the GMFCS in children with bilateral spastic CP after single-event multilevel surgery, using the Gait Profile Score (GPS) as the primary outcome measure. This was a retrospective cohort study of 107 children (46 females, 61 males) with bilateral spastic CP, classified as GMFCS level II or III, who underwent surgery at a single tertiary institution between 1997 and 2008. The mean age at surgery was 10 years 7 months (SD 2 y 8 mo). The primary outcome measure was the GPS. Changes in GMFCS level were studied at multiple time points before and after intervention. Gait dysfunction was partially corrected, with a mean improvement of 28% in the GPS. The GMFCS remained stable and unchanged in 95% of children and improved by one level in 5% of children. The improvement in GPS was three times the minimal clinically important difference. The mean age at final postoperative GPS assessment was 11 years 10 months (SD 2 y 10 mo) and at final GMFCS assessment was 15 years 7 months (SD 3 y 9 mo). Stability of the GMFCS was confirmed in the majority of children with bilateral spastic CP after single-event multilevel surgery, despite statistically and clinically significant improvements in gait dysfunction and functional mobility. This information is important in realistic goal-setting and in counselling families.