Description
Objectives: Post-operative pain after Total Knee Arthroplasty (TKA) is still a concern and non-invasive therapy, such as Pulsed electromagnetic field (PEMF), may be helpful. The aim of this perspective study is to describe preliminary results of safety and efficacy of postoperative non-invasive therapy with the use of PEMF in patients with painful TKA.
Methods: Patients with painful TKA whose pain occurred from at least 30 days after surgery to a maximum of 180 days after surgery were included. All patients were instructed to use local non-invasive biophysical therapy with PEMF (1.5 mT, 75 Hz) for 4 hours a day for 60 days. Visual Analog Score (VAS), SF-12 Health Survey (SF-12), EuroQol (EQ-5D) where used for clinical evaluation and scheduled at 1 month, 2, 6, 12 and 24 months after PEMF treatment. The Knee Society Score (KSS) was scheduled at 3 months of follow-up. The use of nonsteroidal anti-inflammatory drugs (NSAIDs) was also recorded. Patients were divided into three different groups based on the time elapsed between surgery and the beginning of PEMF therapy: Group 1 (30-90 days), Group 2 (91- 150 days) and Group 3 (151-180 days).
Results: One hundred and seven consecutive patients matched the inclusion criteria and were available for analysis. There were 30.8% male, 89.8% primary TKA, 75.8% cemented TKA, 69.2% with non-resurfaced patella, 86% with medial parapatellar approach, 55% of posterior stabilized implants. The reduction in pain and NSAID use was statistically significant compared with baseline as early as one month after PEMF and was maintained at each follow-up (p<0.0001). The EQ-5D and SF-12 Health Survey questionnaires showed significant improvement from baseline to 24-month follow-up (p<0.0001). The KSS showed significantly higher scores, for both functional score (p=0.0001) and knee score (p=0.0006), at 3 months. The analysis for the three subgroups is shown in Figure 1, 2 and 3. PEMF therapy was well tolerated by all patients, with no side effects.
Conclusions: It has been shown that PEMF therapy acts as modulators of A 2A adenosine receptor and inhibits the release of major pro-inflammatory cytokines, such as interleukin-1β,-6,-8, exerting an strong anti-inflammatory effect at the joint. The preliminary results of this study demonstrated good efficacy and safety of Post-operative PEMF therapy in reducing pain and drug consumption after TKA.
