A prospective assessment of the progression of flexed-knee gait over repeated gait analyses in the absence of surgical intervention in bilateral cerebral palsy.

Abstract Background Flexed-knee gait is a common pattern associated with cerebral palsy (CP). It leads to excessive forces on the knee and is thought to contribute to pain and deformity. While studies have shown improvements in mid-stance knee flexion following surgery there remains a lack of prospective data on the progression of flexed-knee gait in the absence of surgery. Research Question Does knee flexion progress over repeated assessments in the absence of surgery in a prospectively assessed cohort with CP? Methods Inclusion criteria were a diagnosis of bilateral CP, knee flexion at mid-stance >19° and no surgery within one year of the first gait analysis. Gait analysis was carried out at six-month intervals (minimum of three and maximum of six assessments). The progression of knee flexion over repeated analyses was assessed. The association between changes in knee flexion between assessments and gender, age, GMFCS level, change in ankle dorsiflexion, change in height and change in weight was examined. Results Forty-eight participants met the initial inclusion criteria and 32 (GMFCS I = 11, II = 17, III = 4) completed the minimum three assessments. Of the 32 included participants, 21 participants (66%) demonstrated decreased knee flexion at mid-stance (mean decrease 6.6°±3.4° ; range 2.0° – 13.0°) and 11 participants (34%) demonstrated increased knee flexion at mid-stance (mean increase 10.4°±7.1° ; range 2.0° – 20.0°) at one-year follow-up. Eighteen (56%) then demonstrated an overall decrease (mean 7.4° ± 5.1°) in knee flexion between the first and last assessment with last follow-up at 1-2 years (n = 3), 2-3 years (n = 3) and 3-4 years (n = 12). The majority of participants (78%) demonstrated episodes of both increasing and decreasing Knee flexion between individual assessments and further analysis found that age was associated with this inter-assessment variability in knee flexion. Significance Flexed-knee gait is not always progressive in bilateral CP and demonstrated variability associated with age.