BACKGROUND: Deep heating therapy (DHT) has shown to improve pain and function in
patients with knee osteoarthritis (OA) in the short term. Benefits of superficial
heating therapy (SHT) are controversial. Long-term effects of both heating
modalities have not yet been investigated.
AIM: To compare the effects of DHT and SHT in patients with symptomatic knee OA,
and to determine the long-term effects of heat therapy.
DESIGN: Double-blind randomized clinical trial.
SETTING: Outpatient clinic of Geriatrics and Physiatrics, University Hospital.
POPULATION: Fifty-four patients with radiologically established diagnosis of
moderate knee OA (Kellgren-Lawrence grade II or III) and pain lasting for at
least three weeks.
METHODS: DHT: local microwave diathermy (three 30-min sessions a week for four
weeks); SHT: application of hot packs (three 30-min sessions a week for four
weeks). Primary outcome measure: Western Ontario and McMaster Universities
(WOMAC) index for the assessment of joint pain, stiffness and physical function
limitations. Secondary outcome measures: British Medical Research Council (BMRC)
rating scale for the evaluation of muscle strength, and a visual analogue scale
(VAS) for pain assessment. Follow up: 24 weeks for all outcome measures; 12
months for the primary outcome.
RESULTS: Intention-to-treat analyses showed a treatment effect in favor of DHT
for all outcome measures. No clinically relevant changes were observed in the SHT
group. Benefits of DHT were maintained over 12 months of follow-up.
CONCLUSIONS: DHT via localized microwave diathermy improves pain, muscle strength
and physical function in patients affected by knee OA, with benefits maintained
over the long term. No clinically relevant improvements were observed in patients
who underwent SHT.
CLINICAL REHABILITATION IMPACT: DHT via microwave diathermy delivered three times
a week for four weeks significantly improves pain and function in patients
affected by moderate knee OA, with benefits retained for at least 12 months. No
clinically relevant changes are observed in knee OA patients treated with SHT.
- Randomized Controlled Trial