title: Percutaneous radiofrequency treatment for refractory anteromedial pain of osteoarthritic knees.
abstract: OBJECTIVE
  Although severe knee osteoarthritis with refractory pain is commonly treated surgically, this is often not an option for patients with poor health status or unwillingness to undergo major surgery. We examined the efficacy of radiofrequency application to sensory nerves as a novel alternative treatment for refractory knee pain.
  
  
  METHODS
  This study was an open-label, nonrandomized, and controlled study. Patients complaining of refractory anteromedial knee pain associated with radiological osteoarthritis (moderate or severe) were included. They were assigned to one of two groups: those receiving radiofrequency thermocoagulation (N = 18) or those receiving nerve block (N = 17), depending on the time period that they were referred to the clinic. Radiofrequency current or local anesthetics was applied to the medial retinacular nerve and the infrapatellar branch of the saphenous nerve. Western Ontario McMaster Universities osteoarthritis index score, pain visual analog scale (VAS), and patient's global assessment were assessed with a minimum follow-up of 6 months.
  
  
  RESULTS
  Radiofrequency treatment significantly decreased knee pain as measured by VAS for 12 weeks compared with the control group. In terms of responders, more patients in the RF group responded to the treatment than in the control group. The differences were statistically significant at 4 weeks, 8 weeks, and 12 weeks in pain VAS. Eight patients (44%) treated with radiofrequency rated excellent or good but only three (18%) in the control group rated good, although the difference was not statistically significant.
  
  
  CONCLUSIONS
  Some patients were able to benefit substantially from radiofrequency treatment. Even if its effective period is limited, radiofrequency application is a promising treatment to alleviate refractory anteromedial knee pain with osteoarthritis. Further experience and technical improvements are needed to establish its role in the management of knee osteoarthritis.
authors.affiliation: Department of Orthopedic Surgery, Kochi Medical School, Kochi University, Nankoku, Japan. ikeuchim@kochi-u.ac.jp
authors.forename: Masahiko
authors.initials: M
authors.lastname: Ikeuchi
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ushida
authors.forename: Masashi
authors.initials: M
authors.lastname: Izumi
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Tani
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000294:innervation / Q000473:pathology / Q000528:radiation effects; D020370:Osteoarthritis, Knee / Q000150:complications*; D010147:Pain Measurement; D010148:Intractable Pain / Q000209:etiology* / Q000532:radiotherapy*; D000078702:Radiofrequency Therapy; D016896:Treatment Outcome