Open Access Technical advance

MR-guided focused ultrasound for the novel and innovative management of osteoarthritic knee pain

Masashi Izumi1, Masahiko Ikeuchi1*, Motohiro Kawasaki1, Takahiro Ushida2, Kazuo Morio3, Hirofumi Namba1, Thomas Graven-Nielsen4, Yasuhiro Ogawa3 and Toshikazu Tani1

Author Affiliations

1 Department of Orthopaedic Surgery, Kochi Medical School, Kochi University, Oko-cho Kohasu, Nankoku 783-850, Japan

2 Multidisciplinary Pain Center, School of medicine, Aichi Medical University, Nagakute, Japan

3 Department of Radiology, Kochi Medical School, Kochi University, Nankoku, Japan

4 Laboratory for Musculoskeletal Pain and Motor Control, Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Aalborg, Denmark

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BMC Musculoskeletal Disorders 2013, 14:267  doi:10.1186/1471-2474-14-267

Published: 13 September 2013

Abstract

Background

Severe knee pain associated with osteoarthritis (OA) is one of the most common and troublesome symptoms in the elderly. Recently, local bone denervation by MR-guided focused ultrasound (MRgFUS) has been demonstrated as a promising tool for pain palliation of bone metastases. The purpose of this study was to develop a novel treatment for knee OA using MRgFUS, and to validate its safety and efficacy.

Methods

Eight patients with medial knee pain and eligible for total knee arthroplasty were included. MR-guided focused sonication treatments were applied to bone surface just below the rim osteophyte of medial tibia plateau with real-time monitoring of the temperature in the target sites. The pain intensity during walking was assessed on a 100 mm visual analog scale (VAS) before and after treatment. Pressure pain thresholds (PPTs) were also evaluated over several test sites adjacent to the sonication area and control sites one month after treatment.

Results

Six patients (75%) showed immediate pain alleviation after treatment, and four of them demonstrated long-lasting effect at 6-month follow up (mean VAS reduction; 72.6%). In responders, PPTs in medial knee were significantly increased after treatment (Median; pre- 358 kpa vs post- 534 kpa, p?<?0.0001). There were no adverse side effects or complications during and after treatment.

Conclusions

These initial results illustrate the safety and efficacy of the newly developing MRgFUS treatment. Significant increase of PPTs on treated area showed successful denervation effect on the nociceptive nerve terminals. MRgFUS is a promising and innovative procedure for noninvasive pain management of knee OA.

Trial registration

Trial Registration: UMIN000010193

Keywords:
MR-guided Focused Ultrasound (MRgFUS); Knee; Osteoarthritis; Pain