Pregabalin Phonophoresis and MET for Knee Osteoarthritis
Evaluating the Combined Efficacy of Pregabalin-Encapsulated Hydrogel Phonophoresis Along With Gastrocnemius Muscle Energy Technique on Neuropathic Pain and Mobility in Grade III Knee Osteoarthritis
University of Faisalabad
35 participants
Jan 1, 2026
INTERVENTIONAL
Conditions
Summary
Knee osteoarthritis (OA) is a common condition causing pain, stiffness, and difficulty walking. Many patients with advanced (Grade III) knee OA also experience neuropathic pain - burning, tingling, or electric shock sensations - which is harder to treat with standard physiotherapy. Oral pregabalin works for neuropathic pain but causes side effects like dizziness and drowsiness. This study tests whether delivering pregabalin through the skin using ultrasound (phonophoresis), combined with calf muscle stretching (Muscle Energy Technique), can reduce nerve pain and improve walking better than ultrasound alone.
Eligibility
Inclusion Criteria8
- Diagnosed Grade III knee osteoarthritis confirmed by Kellgren-Lawrence grading scale (radiograph within past 12 months or newly obtained).
- Neuropathic pain component confirmed by DN-4 questionnaire (score ≥4).
- Age between 40 and 70 years inclusive.
- Both male and female participants.
- Unilateral or bilateral knee involvement (if bilateral, the more symptomatic knee selected for assessment and treatment).
- Willing and able to provide written informed consent.
- Available to attend 4 sessions per week for 4 consecutive weeks (total 16 sessions).
- Able to understand and follow verbal instructions (for MET).
Exclusion Criteria14
- Diabetic neuropathy (diagnosed or DN-4 score attributable to diabetes rather than knee OA).
- Active skin lesions, wounds, infections, or dermatitis on the knee or calf.
- Metal implants (including knee replacement), pacemaker, or other electronic implant (contraindications for ultrasound).
- Received intra-articular knee injection (corticosteroid or hyaluronic acid) within the last 3 months.
- Grade I, II, or IV knee osteoarthritis (Kellgren-Lawrence).
- Aseptic arthritis of knee (rheumatoid, psoriatic, gouty).
- Any lower extremity deformity (genu varum >15°, genu valgum >15°, fixed flexion deformity >15°).
- Previous knee replacement surgery (partial or total).
- Known allergy or hypersensitivity to pregabalin, gabapentin, or any gel components.
- Pregnant or lactating women (ultrasound safety in pregnancy not established for non-obstetric use).
- Concurrent participation in another interventional study.
- Diagnosis of fibromyalgia, complex regional pain syndrome, or other centralized pain disorder that might confound neuropathic pain assessment.
- Active malignancy or history of knee malignancy.
- Deep vein thrombosis or thrombophlebitis in lower limb.
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Interventions
Pregabalin (5% w/w) incorporated into a water-soluble, ultrasound-conductive gel base. Delivered via therapeutic ultrasound (Sonopuls 490, Enraf-Nonius) with parameters: continuous mode, frequency 1 MHz, intensity 1 W/cm², treatment duration 5 minutes, sound head moved in slow circular motion (2-3 cm/sec) over medial, lateral, and posterior knee regions. Approximately 0.5 mL of gel per cm² per session. Administered 4 sessions/week for 4 weeks (total 16 sessions). Prepared under sterile conditions, stored at 4°C, used within 14 days.
Manual therapy technique performed with participant supine, legs extended. Therapist stabilizes distal femur and holds plantar foot. Participant performs plantarflexion isometric contraction against therapist resistance at \~25% maximum effort for 7-10 seconds (no joint movement). After relaxation, therapist passively dorsiflexes ankle to first point of tissue resistance (mild stretch, never pain) and holds for 10 seconds. Cycle repeated 4-5 times per session. Preceded by 10-minute hot pack application. Performed 4 sessions/week for 4 weeks (total 16 sessions).
Standard ultrasound conductive gel containing water, carbomer, propylene glycol, methylparaben, propylparaben (no active pharmaceutical ingredient). Delivered via therapeutic ultrasound (Sonopuls 490, Enraf-Nonius) with parameters: continuous mode, frequency 1 MHz, intensity 1 W/cm², treatment duration 5 minutes, sound head moved in slow circular motion (2-3 cm/sec) over medial, lateral, and posterior knee regions. Administered 4 sessions/week for 4 weeks (total 16 sessions).
Locations(1)
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NCT07598474