Efficacy of therapeutic ultrasound vs sham ultrasound on pain and physical function in people with knee osteoarthritis: A meta-analysis of randomized controlled trials

Table 3 Characteristics of the studies selected for full text review

	Falconer et al[18]	Ozgönenel et al[19]	Tascioglu et al[20]	Yang et al[21]	Loyola-Sánchez et al[22]	Ulus et al[23]
Trial registry number	Not available	Not available	Not available	Not available	NTC00931749	Not available
Trial duration	4-6 wk (12 sessions 2-3 x/wk)	2 wk (10 sessions 5 x/wk)	2 wk (10 sessions 5x/wk)	5 d (5 sessions); + 1 mo follow up	8 wk (24 sessions 3 x/wk)	3 wk (15 sessions 5 x/wk)
Sample size	Randomized: 74; analyzed: 69 (35 CG)	Randomized: 67; analyzed: 65 (31 CG)	Randomized: 90; analyzed: 82 (27 CG)	Randomized and analyzed: 87 (100 knees; 50 CG)	Randomized: 27; analyzed: 25 (13 CG)	Randomized: 42; analyzed: 40 (20 CG)
Sample characteristics (Mean SD/n reported)	Age approximately 67.5 (11) yr; 50 F; All restricted knee ROM ≥ 6 mo; 8 knee joint replacement; 51 bilateral OA	Age approximately 55 (7.5) yr; 54 F; Newly diagnosed; 31 mild OA, 36 moderate OA	Age approximately 60 (3) yr; 56 F; Disease duration 6.5 yr; 48 mild OA, 34 moderate OA	Age 58.3 yr; 72 F; Disease duration 2.8 yr	Age approximately 61.8 (10) yr; 21 F; 8 had mild OA, 19 had moderate OA; 24 bilateral OA	Age approximately 60.5 (9.5) yr; 34 F; disease duration 8.9(8.7) yr; 17 mild OA, 23 moderate OA; all bilateral OA
Ultrasound device	Chattanooga Intellect 200	Peterson .250	Sonopuls 434	NERCUM	Chattanooga Intellect Mobile	Sonopuls 434
Application protocol	12 min; 1 MHz; intensity: 1.7 W/cm2, continuous mode (n = 34)	5 min; 1 MHz; intensity 1 W/cm2; continuous mode (n = 34)	5 min; 1 MHz; intensity 1 W/cm2, continuous mode (n = 27); pulsed (duty cycle 20%, n = 28)	No details: 15min treatment model then 20min rehabilitation model (n = 50 knees)	9.5 min; 1MHz; intensity 1 W/cm2; pulsed mode (duty cycle 20%, n = 12)	10 min; 1 MHz; intensity 1 W/cm2; continuous mode (n = 20)
Sham Application	Start button not pushed	Applicator disconnected from back of device	No output delivered	No output delivered	Ceramic crystal removed from soundhead	No output delivered and applicator disconnected from back of device
Application site	Knee flexed or extended per most restricted motion; treated surface area 100 cm2	Patellofemoral and tibiofemoral borders; treated surface area 25 cm2	Antero-medial and lateral parts of extended knee; treated surface area 60 cm2	Knee extended; 4 soundheads fixed on joint line; treated surface area not reported	Knee flexed to 90°; Soundhead fixed at antero-medial joint line. treated surface area 5 cm2	Antero-medial and lateral parts of extended knee; treated surface area 60 cm2
Dosage	26 J/cm2	150.7 J/cm2	196.3 J/cm2 39.3 J/cm2	Unable to calculate	114 J/cm2	196.3 J/cm2
Concurrent treatment	Stretching, joint mobilizations, exercises (ROM, bridging, isometric quads, home program)	none	none	none	None reported; use of analgesics not reported	Hotpacks (20 min); IFC (10 min); exercises (isometric quads); analgesics except during physio
Outcomes included in meta-analysis	Pain – 10 cm VAS	Pain on movement in past wk – 10 cm VAS WOMAC LK 3.1 Physical Function subscale Walking speed [time (s) to walk 50 m]	Pain on movement in past wk – 10 cm VAS Walking speed [time (s) to walk 20 m]	none	Pain following walking test – 11 point NRS WOMAC LK 3.1 Physical Function subscale Distance (m) walked in 6 min	Pain on activity – 10 cm VAS WOMAC LK 3.1 Physical Function subscale Walking speed [time (s) to walk 50 m]
Funding source	Non-profit	Not reported	Not reported	NERCUM, institutional	Government	Unfunded
Comments	Trial author confirmed mode was continuous; pain data extracted from graphs; request for pain and walking data was unsuccessful		Treated surface area not reported; estimated to be 3x the sound head size (based on parts of knee treated)	Attempts to contact authors for pain and physical function data that could be pooled were unsuccessful	1 of the 2 reviewers co-authored the trial; outcomes pooled in this review were secondary outcomes in trial	Treated surface area not reported; estimated to be 3x the sound head size (based on parts of knee treated)

OA: Knee osteoarthritis; CG: Control group; F: Female; NERCUM: National Engineering Research Centre of Ultrasound Medicine; ROM: Range of motion; IFC: Interferential current electrotherapy; VAS: Horizontal visual analogue scale (10 = worst pain); NRS: Numeric rating scale (10 = worst pain); WOMAC LK 3.1: Western Ontario and McMaster Universities Osteoarthritis Index (Likert scale version) self-report questionnaire physical function subscale (68 = worst limitation).