As per the study results published in 'Annals of the Rheumatic Diseases' the use of LDRT for knee osteoarthritis (OA) is not advisable.

In spite of the absence of controlled studies, LDRT for benign disorders, for example, knee OA is widely used in some parts worldwide. Elien A M Mahler et al. investigated the effects of LDRT on symptoms and inflammation in patients with knee OA.

The patients (total 55 patients divided into 27 (49%) to LDRT and 28 (51%) to sham) with knee OA (clinical ACR criteria), aged ≥50 years, pain score ≥5/10 and non-responding to analgesics and exercise therapy were considered for this randomised, double-blinded, sham-controlled clinical trial (RCT). The patients were randomised 1:1 to get LDRT (1 Gray per fraction) or sham intervention six times in 2 weeks, divided by pain (<8 versus ≥8/10). The proportion of OMERACT-OARSI responders, 3 months post intervention comprised the primary outcome. Pain, function and inflammatory signs examined by ultrasound, MRI and serum inflammatory markers were under the secondary outcomes. There were 12/27 patients (44%) in the LDRT vs 12/28 patients (43%) in the sham group who responded at 3 months post-intervention. A difference of 2% (95% CI 25% to 28%), OR adjusted for the stratifying variable was 1.1 (95% CI 0.4 to 3.2). No differences perceived for clinical and any of the inflammatory signs. There was no substantial advantageous effects on symptoms and  inflammatory signs of LDRT in patients knee OA than the sham treatment.