The effect of end-of-range grade A+ knee mobilisation following acute primary total knee arthroplasty: A randomised controlled trial

Background/Aims: Although the number of total knee arthroplasty procedures being performed is increasing worldwide, the rehabilitation protocols following surgery are poorly studied in the literature. Research suggests that exercise therapy and joint mobilisation are recommended in the later stages of osteoarthritis. However, best practice for rehabilitation in the immediate postoperative period is yet to be determined. This prospective randomised controlled trial examined whether adding grade A+ joint mobilisation to the standard in-hospital rehabilitative approach would increase pain (based on recordings of pain intensity on the visual analogue scale) and improve range of motion in the knee. Methods: Participants (n= 32; mean +/- SD age: 71.1 +/- 8.9 years) undergoing primary total knee arthroplasty at a university hospital were randomly assigned to two equal groups. Measurements were recorded before surgery and on the first, third and seventh days following total knee arthroplasty. All participants received standard care postoperatively, with participants in the experimental group receiving additional grade A+ joint mobilisation for knee flexion and extension twice a day for 20 minutes using the JAS Knee system (Joint Active Systems (R), Effingham, Illinois). Results: There were no statistically significant differences in visual analogue scale scores or range of motion in all measurements (p > 0.05). Increased range of motion at a faster pace was observed in the obese subgroup of patients (p = 0.016). Other factors such as age, body mass index, type of anaesthesia and implant model did not influence the final outcome. Conclusions: Early grade A+ joint mobilisation combined with the standard in-hospital rehabilitative approach is safe to be used during the post-acute phase of rehabilitation after total knee arthroplasty. Despite increasing trends in the obese subgroup of patients, adding grade A+ joint mobilisation to the standard protocol did not significantly improve overall range of motion. The results of this study and heterogeneities in the literature identify the need for further research and development in this area.