Understanding Two Common — and Often Confused — Causes of Knee Pain
Knee pain is one of the most common reasons patients seek orthopedic care. Two conditions that are frequently confused—yet very different in cause and management—are meniscus tear and patellofemoral pain syndrome (PFPS).
Although both can cause discomfort during walking, exercise, or daily activities, they involve different structures of the knee and require different treatment approaches.
This article explains the key differences between a meniscus tear and patellofemoral pain syndrome, including symptoms, causes, diagnosis, and long-term implications.
Quick Comparison Overview
| Feature | Meniscus Tear | Patellofemoral Pain Syndrome |
| Main structure involved | Meniscus (cartilage cushion) | Patella (kneecap) & femoral groove |
| Pain location | Deep inside the knee or joint line | Front of the knee |
| Common triggers | Twisting, squatting, pivoting | Stairs, running, prolonged sitting |
| Mechanical symptoms | Locking, catching, clicking | Grinding, Crepitus |
| Swelling | Often significant/localized | Rare or very mild |
| Primary issue | Structural damage | Biomechanical overload |
What Is a Meniscus Tear?
The meniscus is a C-shaped cartilage structure that acts as a shock absorber between the thigh bone (femur) and shin bone (tibia). Each knee has a medial and lateral meniscus.
Common causes
- Sudden twisting or pivoting movements
- Sports injuries
- Degenerative wear in aging knees
Typical symptoms
- Pain along the joint line (inside or outside of the knee)
- Swelling that develops over hours to days
- Clicking, catching, or locking sensation
- Feeling that the knee may “give way”
- Pain with deep squatting or rotation
Meniscus tears are structural injuries, meaning there is actual tissue damage.
What Is Patellofemoral Pain Syndrome (PFPS)?
Patellofemoral pain syndrome involves pain arising from the interaction between the kneecap (patella) and the femoral groove it slides within.
Unlike meniscus tears, PFPS is usually not caused by torn tissue, but by maltracking, overload, or imbalance.
Common causes
- Muscle imbalance (weak quadriceps or hip stabilizers)
- Poor knee alignment
- Overuse (running, stairs, squats)
- Prolonged sitting with bent knees (“movie-theater sign”)
Typical symptoms
- Dull or aching pain at the front of the knee
- Pain when climbing stairs or running downhill
- Discomfort after sitting for long periods
- Pain during squats or lunges
- Usually no locking or catching
PFPS is primarily a biomechanical problem, not a structural tear.
Key Differences in Pain Location
- Meniscus tear: Pain is deeper inside the knee and often localized to the inner or outer joint line.
- Patellofemoral pain syndrome: Pain is felt at the front of the knee, around or behind the kneecap.
Pain location is often the first clinical clue in distinguishing these conditions.
Where Does Stem Cell Therapy Fit In?
Stem cell therapy is not a primary treatment for either meniscus tears or patellofemoral pain syndrome.
However, in selected cases, it may be considered as part of a joint-preservation strategy, particularly when degenerative changes are present.
When stem cell therapy may be considered
- Degenerative (wear-related) meniscus changes, not acute traumatic tears
- Early knee osteoarthritis coexisting with meniscus pathology
- Chronic joint inflammation not responding to conservative care
- Patients aiming to delay or avoid surgical intervention
Stem cell therapy focuses on:
- Modulating joint inflammation
- Supporting the joint environment
- Promoting cartilage homeostasis
It does not:
- Repair a torn meniscus mechanically
- Correct patellar tracking or muscle imbalance
This is why proper diagnosis and patient selection are essential before considering regenerative options
Meniscus tears and patellofemoral pain syndrome are different problems with different solutions.
- Meniscus tears involve structural cartilage damage
- PFPS involves biomechanical overload at the kneecap
- Stem cell therapy may play a supportive role in selected degenerative cases
Accurate diagnosis is the foundation of effective knee care.
About EDNA Wellness
EDNA Wellness is a private Stem Cell Clinic and Regenerative Medicine Center in Bangkok, Thailand, specializing in Umbilical cord–derived Mesenchymal Stem Cells (UC-MSCs) for knee osteoarthritis and joint pain, stroke and other neuro-related conditions, and stem cell IV infusions for longevity and healthy aging. All treatments are doctor-designed and performed in a sterile clinical setting.
For more information or to book a consultation:
LINE: @ednawellness
WhatsApp: +66 (0) 64 505 5599
Website: www.ednawellness.com
References
- Beaufils P, et al. Management of meniscal tears and degenerative lesions. EFORT Open Rev.
- Crossley KM, et al. Patellofemoral pain syndrome. Nat Rev Dis Primers.
- AAOS. Meniscus Tears and Knee Pain.
- Powers CM. Patellofemoral pain: biomechanics and treatment strategies. J Orthop Sports Phys Ther.