Pulse-dose radiofrequency for knee osteoartrithis.
OBJECTIVE
Knee osteoarthritis (OA) is a leading cause of disability in the elderly. The purpose of this study was to investigate the effectiveness of pulse-dose radiofrequency (PDRF) in patients with chronic pain refractory to conservative therapies.


METHODS
Between January 2011 and November 2012, PDRF was performed on 40 patients. A 20-gauge cannula, 10 cm in length, was introduced in the antero-lateral region of the interested knee, and its tip was placed in the joint space under fluoroscopic guidance. After the spindle was removed, an RF needle with a 10-mm "active tip" was introduced. PDRF was performed with 1,200 pulses at high voltage (45 V) with 20-ms duration followed by a 480-ms silent phase.


RESULTS
Mean VAS scores before the procedures was 6.8 ± 0.8. A great decrease of pain intensity was achieved 1 week after PDRF (mean VAS scores 1.8 ± 0.4 [p < 0.05]) with stabilization of painful symptomatology in the following months and excellent results 1 year after treatment (mean VAS scores 2.3 ± 0.6 after 12 months [p < 0.05]). Western Ontario and McMaster Universities Index of Osteoarthritis scores showed improved quality of life in all patients at 6 months (p < 0.05) and at 1 year (p < 0.05) after PDRF. No patients developed complications.


CONCLUSIONS
This study successfully investigated the effectiveness of PDRF in patients with chronic pain unresponsive to conservative therapies. PDRF seems to be an effective and reliable technique for palliative management of chronic pain in patients with knee OA.
Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiation Therapy, University "Tor Vergata", Viale Oxford 81, 00133, Rome, Italy, salva.masala@tiscali.it.
Salvatore
S
Masala
Roberto
R
Fiori
Mario
M
Raguso
Marco
M
Morini
Eros
E
Calabria
Giovanni
G
Simonetti
D000368:Aged; D059350:Chronic Pain / Q000209:etiology / Q000628:therapy*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000150:complications / Q000175:diagnosis / Q000628:therapy*; D010147:Pain Measurement; D056888:Patient Positioning; D011446:Prospective Studies; D061208:Pulsed Radiofrequency Treatment / Q000379:methods*; D012720:Severity of Illness Index; D016896:Treatment Outcome