COMPARISON OF THE EFFECT OF ULTRASOUND VERSUS LASER ON PAIN AND FUNCTION IN SUBJECTS WITH OSTEOARTHRITIS KNEE

Background:Osteoarthritis(OA) is a degenerative joint disease which leads to loss of hyaline articular cartilage associated with underlying bony changes. Knee osteoarthritis(KOA) is associated with pain and functional impairment which negatively affects the patients quality of life. Ultrasound and LASER have been found effective in KOA but studies comparing the two are less.

Method:An experimental study was conducted with 21 patients of unilateral KOA randomized into three groups. Each group had 7 patients. Group A- Ultrasound- 1MHz, Pulsed1:1, 0.8W/cm², 10 min on medial knee joint line. Group B- LASER- 7.6J for 1 min and 30 sec for each trigger point. Group C-Conventional physiotherapy. All subjects received conventional physical therapy with hot packs and quadriceps exercise of affected knee. Outcome measures used were Numerical pain rating scale(NPRS), Sit to stand(STS) and Timed up and go test(TUG).

Result:Using Wilcoxon test, mean difference in painin Group A(W=-2.414,p=0.016), GroupB(W=-2.460,p=0.014 ), GroupC(W=-2.392 ,p=0.017). Mean difference in STS in GroupA(W=-2.392,p=0.017 ), Group B(W=-2.392,p=0.017 ), Group C(W=-2.428,p=0.015). Mean difference in TUG, Group A(W=-2.366,p=0.018),GroupB(W=-2.371,p=0.018 ) Group C(W=-2.375 ,p=0.018 ). Applying Kruskal-Wallis test, mean difference between the groups, for pain(KW=6.612,p=0.037), STS(KW=3.020,p=0.221) and TUG(KW=7.822,p=0.020). Applying Bonferronis post hoc test mean difference in pain between groups Aand B was statistically significant(p=0.03), and mean difference in TUG between groups Band C was statistically significant(p=0.013).  

Conclusion:Ultrasound,LASER and conventional physiotherapy are effective in reducing pain, improving function and mobility in subjects with OA knee. LASER is more effective than ultrasound and conventional PT for pain and more effective than conventional PT for mobility.