Acupuncture treatment

The acupoints for the acupuncture intervention will include Dubi (ST 35), Neixiyan (EX-LE4), Ququan (LR8), Xiyangguan (GB33), Xuehai (SP10), Sanyinjiao (SP6), Taixi (KI3) and an ashi point (the point where the patient feels most pain). An adhesive pad will be placed on the skin above the acupoints according to WHO Standard Acupuncture Locations, and then a single-use sterile needle (0.25 × 40 mm or 0.25 × 25 mm, Hwato, Suzhou, China) will be used to penetrate into the skin 5–20 mm through the adhesive pad (Fig. 2). Acupuncturists will manually stimulate the needles to achieve de qi (mainly including the sensations of numbness, distention, soreness and heaviness), and then the needles will be left in place for 30 min. Table 1 and Fig. 2 show the location of acupoints for acupuncture.

The picture of acupuncture and sham acupuncture. a Location of acupoints and non-acupoints. Red circles: Acupoints used in acupuncture group. Blue circles: Non-acupoints used in sham acupuncture group. b The diagrammatize of acupuncture and sham acupuncture. Abbreviation: ST35 Dubi, EX-LE4 Neixiyan, LR8 Ququan, GB33 Xiyangguan, SP10 Xuehai, SP6 Sanyinjiao, KI3 Taixi. NA, non-acupoint

Locations of acupoints for acupuncture

On the anterior aspect of the knee, in the depression lateral to the patellar

Ligament

On the anterior aspect of the knee, in the depression medial to the patellar

Ligament

^a1 cun (≈ 20 mm) is defined as the width of the interphalangeal joint of patient’s thumb