RA with Knee involvement

I have a patient with a 5 year history of RA with predominently involvement of her both Knees. Subjectively patients complain a lot of pain in her lower limbs with difficulty in walking almost wheel chair bound, unable to climb stairs with functional activities restriction for 3 months. She is having a good rigimne of immunosupressive, corticosteriods and NSAIDs, with a referral to physiotherapy. On objective examination she has a good range of motion in her lower limb joints, with effusion and synovitis in her both knee, slight quadriceps atrophy, painful ROM of her both knees and legs, inability on stairs climbing, walking and functional activities. Her plan of Physiotherapy is as under:

Combination therapy: Swd application both Knees for 20 minutes + ultrasound therapy (Phonophoresis with Movelat Gel) for 10 minutes both knees.

Active ROM exercises both Knees for 10 repitition twice a day
Isometric Quadriceps exercises both Knees 20- 50 repitition twice a day

Gait Training

After getting treatment session for 2 weeks of Physiotherapy the patient started to walk with good gait without the need of wheel chair but she had difficulty in climbing the stairs. She did not reported marked relief of pain and climbing the stairs subjectively and did not have any remarkable reduction of her synovitis and effusion objectively. She felt that she need a further second consultation with her rheumatologist. What are the suggestions or ideas to improve her both subjectively and objecively and in her functional independence. Does application of TENS may bring about marked relief in her pain? Plz reply with some good views and evidence based reviews, studies or your experience.