The major aim of the study was (1) to compare the physiotherapy management in patients treated with autologous chondrocyte implantation (ACI) versus microfracture (MF) at the knee using a standardized rehabilitation protocol; and (2) to investigate the effect of activities in low-load conditions after surgery on the functional recovery was explored. 95 physiotherapists received a standardized rehabilitation protocol that was used in a randomized controlled trial. A secondary analysis on patients’ outcome was studied in a cohort design. An electronic report form including 18 physiotherapy variables was used to compare physiotherapy management. Patients’ functional outcome was assessed using the KOOS (Knee Injury Osteoarthritis Outcome Score) and the pooled symmetry index (SI) based on one strength and three hop tests. Both subjective and objective outcomes were evaluated pre-surgery, and at 1 and 2 years post-surgery. 65 physiotherapists adhered very consistently to the protocol during the first 3 months and showed a similar preference and timing for the physiotherapy modalities in both treatment groups. Patients with high amount of low-load activities (LLA+, n=21) post-surgery performed significantly better compared to patients with low amount of LLA (LLA−, n=17). At 24 months the mean pooled SI of LLA+ cohort was 92.4 compared to 78.2 for LLA− cohort (95% confidence interval [CI] 1.8 to 26.2).
Overall, the compliance post-surgery with the rehabilitation protocol was excellent and the applied rehabilitation was comparable in both treatment groups. A high amount of low-load activities post-surgery appears beneficial for the objective functional outcome.