A comparison of 2 continuous passive motion protocols after total knee arthroplasty: a controlled and randomized...

Area of Science:

• Orthopedics
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Total knee arthroplasty (TKA) is a common procedure to alleviate pain and restore function in patients with severe knee osteoarthritis.
• Postoperative rehabilitation, including continuous passive motion (CPM), plays a crucial role in optimizing outcomes after TKA.
• Optimal CPM protocols for maximizing range of motion and functional recovery following TKA remain under investigation.

Purpose of the Study:

• To evaluate the effect of different continuous passive motion (CPM) protocols on outcomes after total knee arthroplasty (TKA).
• To compare an early flexion CPM protocol against a standard CPM protocol and a no-CPM control group.
• To assess the impact of these protocols on range of flexion, pain, and functional scores at various postoperative time points.

Main Methods:

• A prospective randomized controlled study involving 147 patients undergoing TKA.
• Three groups were established: standard CPM (gradual increase from 0-40 degrees), early flexion CPM (90-50 degrees progressing over 3 days), and a no-CPM control group.
• CPM was administered twice daily for 3 hours over 5 days, alongside a standardized physiotherapy program. Assessments were conducted preoperatively and at day 5, 3 months, and 1 year postoperatively.

Main Results:

• The early flexion CPM group demonstrated significantly greater range of flexion at day 5 compared to both the standard CPM and no-CPM groups.
• No statistically significant differences were observed between the three groups for other tested variables (e.g., pain, functional scores) at any of the assessed time points.
• The findings suggest a short-term benefit of early aggressive flexion in CPM for initial range of motion gains.

Conclusions:

• An early flexion continuous passive motion (CPM) protocol may enhance immediate postoperative range of motion following total knee arthroplasty (TKA).
• The study did not find significant long-term differences in other key outcomes between the early flexion, standard CPM, and no-CPM groups.
• Further research may be warranted to explore the long-term clinical significance of early flexion gains and to refine optimal CPM parameters for TKA rehabilitation.