OrthoBethesda
10215 Fernwood Road, Suite 506Bethesda, MD 20817(301) 530-1010
Knee Specialist
Knee pain specialist — arthritis & tendon injuries
The short answer
Dr. Gruner is a knee specialist offering a comprehensive, non-surgical approach to knee arthritis, patellar and quadriceps tendinopathy, and more. From physical therapy and innovative injections (PRP, microfragmented fat, viscosupplementation) to procedures like Tenex and tendon scraping, he builds a personalized plan to reduce pain and restore mobility.
Medically reviewed by Marc Gruner, DO, MBA, RMSK
Sports medicine physician, Mayo Clinic fellowship. Last reviewed June 2026
If you're experiencing knee pain or arthritis, Dr. Gruner offers comprehensive diagnosis and treatment. Knee arthritis develops as the cartilage between the thigh bone and shin bone wears down, while tendon problems around the kneecap come from overuse.
From non-invasive options like physical therapy and innovative injections (PRP, microfragmented fat, gel/viscosupplementation) to minimally invasive procedures such as Tenex and tendon scraping, Dr. Gruner creates a personalized plan to help you regain mobility and reduce pain — delaying or avoiding knee replacement.
What is knee pain?
The knee absorbs enormous forces with every step, so it's one of the most common sources of orthopedic pain. Pain can come from the joint surface (arthritis), the tendons around the kneecap (patellar and quadriceps tendinopathy), the meniscus cartilage, or the ligaments. The location often hints at the cause — pain on the inside or outside of the joint suggests arthritis or meniscus, while pain right at or below the kneecap suggests a tendon problem.
Knee pain may be accompanied by swelling, stiffness, grinding, or a sense of instability, and it frequently worsens with stairs, squatting, and prolonged activity.
What causes knee pain?
Knee osteoarthritis results from cartilage wear related to prior trauma, the shape of the knee, meniscus injury, and aging. Patellar tendinopathy (jumper's knee) and quadriceps tendinopathy come from overuse. Runners commonly develop patellofemoral pain, IT band syndrome, and meniscus irritation.
How is knee pain treated without surgery?
For arthritis, Dr. Gruner combines activity and weight strategies, physical therapy, and injections — from cortisone and gel (viscosupplementation) to orthobiologics like PRP and microfragmented fat — to reduce pain and delay or avoid knee replacement. For tendon problems, progressive loading is the foundation, with ultrasound-guided PRP, Tenex, or tendon scraping for stubborn cases.
Knee conditions we treat
Knee ArthritisCartilage wear in the knee causing pain and swelling — often managed without surgery.Patellar Tendinopathy (Jumper's Knee)Pain below the kneecap from overuse of the patellar tendon.Quadriceps TendinopathyPain above the kneecap from overuse of the quadriceps tendon.IT Band Syndrome (Runner's Knee)Outer-knee pain from iliotibial band irritation, common in runners and cyclists.Meniscus TearsTears of the knee's cartilage cushion — many degenerative tears improve without surgery.Baker's CystA fluid-filled swelling behind the knee, usually a sign of an underlying joint problem.
Treatments and procedures for the knee
PRPConcentrated platelets from your own blood, injected under ultrasound guidance to support healing in joints and tendons.Microfragmented AdiposeA minimally processed sample of your own fat — microfragmented adipose tissue (MFat) — injected to cushion and support arthritic or injured joints.BMACCells and growth factors concentrated from your own bone marrow for select joint and tendon conditions.MSK UltrasoundIn-office, real-time imaging of tendons, ligaments, nerves, and joints — no radiation — to pinpoint the source of pain.TenexUltrasound-guided removal of damaged tendon tissue through a tiny opening — no open surgery.Tendon ScrapingA 2mm procedure that removes pain-causing tissue from the tendon's surface while preserving the tendon.
Rehabilitation protocols
What to expect week by week after your procedure. Your plan is individualized; follow these alongside your physical therapist.
Knee (Quad / Patellar Tendon) — Ultrasound-Guided PRP / Tenotomy Protocol
Download full protocol (PDF)
Week 0–1
Protect, reduce pain and swelling
- Non-weight-bearing with crutches ~4 days; knee immobilizer 1 week
- Begin gentle active knee ROM
- Gait training with crutches
Weeks 1–2
Restore ROM, progress weight bearing
- Continue knee ROM
- Begin core and lower-limb strengthening
- Upper-body aerobic/strength work; optional BFR
Weeks 2–4
Improve strength and tendon tolerance
- Begin isometric knee strengthening
- Joint mobilizations as needed
- Non-impact aerobic (bike); pool once incision healed
Weeks 4–6
Normalize gait, add balance
- Progress knee strengthening
- Initiate balance/proprioception
Weeks 6–8 (return to play)
Gradual return to sport
- No painful activities; no soreness > 24 hrs; no pain with running
- Gradual return to sport activities
Do not use NSAIDs (ibuprofen, Aleve, aspirin) for 4 weeks, and avoid ice for the first week — both blunt the healing response. Acetaminophen (Tylenol) is fine for discomfort. Care is tailored to you; use these guidelines with your physical therapist.
Knee & Hip Joint — Ultrasound-Guided PRP / Adipose / BMAC Injection Protocol
Download full protocol (PDF)
Day 1–2
Protect the joint
- Weight-bear as tolerated; crutches as needed
- Keep bandage dry; no submerging for 72 hours
- Gentle ROM as tolerated; monitor wound
Day 3–7
Begin gentle loading
- Avoid excessive joint loading
- Start low-grade closed-chain program
- Light squats/lunges (bodyweight); optional BFR
Day 8–14
Add resistance
- Avoid impact and heavy lifting to the joint
- Light open-chain exercises; add resistance as tolerated
- May begin swimming and low-resistance biking
Day 14–28
Functional progression
- Avoid impact activities
- Progress functional program; light agility and proprioception
- Resume light aerobic activity (walking)
Beyond 28 days
Long-term prevention
- Establish a long-term home exercise program
- Correct biomechanical issues that contributed to the injury
Do not use NSAIDs (ibuprofen, Aleve, aspirin) for 4 weeks, and avoid ice for the first week — both blunt the healing response. Acetaminophen (Tylenol) is fine for discomfort. Care is tailored to you; use these guidelines with your physical therapist.
Frequently asked questions
- What are the alternatives to knee replacement?
- Physical therapy, weight and activity management, and injections — cortisone, gel (viscosupplementation), PRP, or microfragmented fat — can reduce pain and improve function, often delaying or avoiding knee replacement for years.
- Does PRP work for knee arthritis?
- For many patients with mild-to-moderate knee osteoarthritis, ultrasound-guided PRP reduces pain and improves function, with benefits that studies suggest can last a year or longer.
Request an appointment
Schedule a comprehensive evaluation to discuss your non-surgical treatment options.
Bethesda, MD 20817(301) 530-1010