Background & Aims
Knee pain secondary to osteoarthritis (OA) is a common cause of chronic pain. Treatment modalities consist of conservative approaches, pharmacological interventions, and interventional procedures. In addition to debilitating pain, knee OA is associated with a decline in strength of quadriceps muscle secondary to disuse atrophy. Studies have demonstrated that these can be improved after specific interventions targeted at pain relief. Only three studies have assessed the effect of intra articular nonsurgical interventions on muscle strength. Two studies were conducted to assess the effect of intra articular hyaluronic acid injections, while one study assessed the effect of platelet rich plasma on muscle power. No study has been conducted to evaluate the effect of radiofrequency ablation (RFA) of genicular nerves on the knee muscle strength. Aim of the present randomized, double blind placebo-controlled trial was to evaluate the effect of RFA of genicular nerves on pain, functionality an
Methods
Fifty-four patients between 40 – 70 years, with chronic OA knee, visual numeric rating scale (VNRS) of > 50 and Kallgren Lewis grading (KL grade) of 2 or more, not responding to conventional treatment modalities were randomized into two groups of 27 patients each. Group 1 received continuous RFA to genicular nerves while Group 2 underwent a sham procedure under LA. Patients in both groups were asked to follow a standard physiotherapy regimen for three months. Primary outcome of the study was to assess the changes in knee muscle strength using a isokinetic peak torque measurement with IsoforceTM isokinetic dynamometer at 3 months. VNRS, Western Ontario and McMaster Universities Osteoarthritis index (WOMAC) scores, Global perceived effect (GPE) of the procedure and compliance to physiotherapy were the secondary outcomes assessed.
Baseline isokinetic knee strength for extension at 60/sec (Nm) has been reported to be 72.4 +/- 22.79 To target an improvement of 25% in extension at 60/sec
Results
Isokinetic peak torque values of flexion at 60 and 180 degrees/sec of Group 1 were found to be significantly higher than that of Group 2 at the end of 3 months (27.16 ± 14.24 Nm in Group 1 and 22.93 ± 6.83Nm in Group 2 at baseline vs 37.56 ± 14.20 Nm in Group 1 and 28.73 ± 7.14 Nm in Group 2 at 3 months, p value = 0.01). There was no significant difference in peak torque values of extension of knee joint. There was significant reduction in pain scores of patients in Group 1 (73.52 ± 14.20 at baseline vs 37.04 ±17.77 at 3 months, p = 0.00). Patients in Group 2 had significantly higher VNRS scores at 2 weeks, 1 month and 3 months respectively. (P value = 0.00, Student’s t test). On intergroup comparison, VNRS of both groups were significantly different with higher scores in Group 2 when measured at 2 weeks, 1 month and 3 months respectively. WOMAC scores of both groups were significantly different at 2 weeks, 1 month and 3 months with higher scores indicating reduced functionality in Gro
Conclusions
Application of RFA to genicular nerves in chronic OA knee patients resulted in better pain relief, improved functionality and increase in muscle strength at flexion. No significant improvement in extensor muscle strength was observed in those who received RFA as compared to those who did not
References
1.Garstang SV, Stitik TP. Osteoarthritis: epidemiology, risk factors, and pathophysiology. Am J Phys Med Rehabil 2006; 85: 2-11.
2.Choi WJ, Hwang SJ, Song JG, Leem JG, Kang YU, Park PH et al. Radiofrequency treatment relieves chronic knee osteoarthritis pain: a double – blind randomised controlled trial. Pain 2011; 152: 481-87
3.Sun SF, Hsu CW, Hwang CW, et al. Hyaluronate improves pain, physical function and balance in the geriatric osteoarthritic knee: a 6-month follow-up study using clinical tests. Osteoarthritis Cartilage 2006;14:696–701
4.Tang SFT, Chen CPC, Chen MJL, Hong WH, Yu TY, Tsai WC. Improvement of muscle strength in osteoarthritic knee patients after intraarticular knee injection of hyaluronan. Am J Phys Med Rehabil 2005;84:274–77.
5.Miltner O, Schneider U, Siebert CH, et al. Efficacy of intra articular hyaluronic acid in patients with osteoarthritis—a prospective clinical trial. Osteoarthritis Cartilage. 2002;10:680–86.
6.Wu YT, Hsu KC, Li TY, Chang CK, Chen LC. Effects of platelet-rich plasma on pain and muscle strength in patients with knee osteoarthritis. Am J Phys Med Rehabil 2018; 97:248–254
Presenting Author
Jeetinder Kaur
Poster Authors
Jeetinder Makkar
MD
Postgraduate Institute of Medical Education and Research Chandigarh
Lead Author
Babita Ghai
Post Graduate Institute of Medical Education & Research Chandigarh
Lead Author
Vijay Goni
Post Graduate Institute of Medical Education & Research Chandigarh
Lead Author
Monica Chhabra
Post Graduate Institute of Medical Education & Research Chandigarh
Lead Author
Pradip Kumar Sarkar
Post Graduate Institute of Medical Education & Research Chandigarh
Lead Author
Topics
- Joint Pain