Stem Cell Therapy for Knee Pain: A Patient's Complete Guide

Knee pain is one of the most common reasons patients come to us. It's also one of the most commonly misdiagnosed by the broader medical system, because "knee pain" can mean half a dozen different things, and the right treatment depends entirely on which one is actually causing the symptoms.

This guide walks through how we think about knee pain at Apex: how we sort the indications, when cellular therapy is the right tool, when PRP is enough, when surgery is the right answer, and what realistic expected outcomes look like for each category. It pairs with our evidence review (which goes deeper into the literature) and our decision guide on regenerative therapy and surgery.

If you're trying to figure out whether regenerative care is right for your knee, this is the long version of the conversation we'd have at consultation.

What's actually wrong with your knee?

The knee is a structurally complex joint. Pain in the knee can come from:

Articular cartilage damage. The smooth surface lining the ends of the bones wears down with time, injury, or repetitive load. This is osteoarthritis when diffuse, or a focal "chondral defect" when localized.

Meniscal injury. The two C-shaped cartilage pads (medial and lateral menisci) can tear, fray, or extrude. Some meniscal tears cause symptoms, many don't.

Subchondral bone changes. The bone underneath the cartilage develops cysts, sclerosis (hardening), and edema as the joint degenerates. These changes are often the actual pain generator, more than the cartilage itself.

Ligamentous injury. The ACL, PCL, MCL, and LCL can be sprained, partially torn, or completely torn. Complete tears of the ACL typically require surgical reconstruction.

Patellofemoral problems. Pain at the front of the knee around the kneecap, from cartilage wear under the patella, malalignment, or chronic overload.

Tendinopathy. Patellar tendon (jumper's knee), quadriceps tendon, distal hamstring tendons, pes anserinus tendon.

Bursitis. Inflammation of one of several bursae around the knee.

Referred pain. Hip pathology can present as knee pain; lumbar radiculopathy can present as knee pain.

A single patient often has multiple things going on at once. The 58-year-old with moderate OA also has a small meniscal tear, mild patellar tendinopathy from compensating, and some pes anserinus bursitis. The right protocol addresses what's actually driving the symptoms.

The workup

For knee pain at Apex, the workup typically includes:

History. When the problem started, what makes it better or worse, what you've tried, your activity level, your goals. The history sorts patients into rough categories before any imaging is reviewed.

Targeted exam. Range of motion, ligament stability testing (Lachman, anterior drawer, valgus and varus stress), meniscal provocation tests (McMurray, Apley), patellofemoral evaluation, gait analysis, palpation of specific structures (joint line, tendons, bursae). Hip and ankle screen because both contribute to knee pain commonly.

Imaging review. Weight-bearing X-rays show joint space, alignment, and bony changes. MRI shows cartilage detail, meniscal pathology, ligament integrity, bone marrow edema, and soft tissue inflammation.

Targeted labs when relevant. If the picture suggests inflammatory arthritis or systemic contributors, basic inflammatory markers, metabolic studies, and sometimes more specific serologies.

The workup usually produces a clear picture within 60 to 90 minutes. The protocol falls out of the picture, not the other way around.

Knee osteoarthritis by KL grade

The Kellgren-Lawrence (KL) grading system is the standard for knee OA. Treatment shifts substantially across the grades.

KL grade I (doubtful)

Doubtful narrowing of joint space, possible osteophytic lipping. Symptoms usually mild and intermittent. The pain may not even be from arthritis; consider other contributors.

Typical approach: Conservative care first. PT, weight management, activity modification, OTC anti-inflammatories. Injection-based therapy rarely warranted. If you've genuinely failed conservative care and want a regenerative option, PRP is the appropriate tool.

KL grade II (mild)

Definite osteophytes, possible joint space narrowing. Symptoms often more consistent. The cartilage damage is starting to matter clinically.

Typical approach: PRP is the typical right answer. Some patients with active lifestyles or specific functional demands benefit from cellular therapy at this stage, but for most KL II patients, PRP delivers good value. Series of 2 to 3 PRP injections, separated by 4 to 6 weeks, with re-evaluation at 12 weeks.

KL grade III (moderate)

Moderate multiple osteophytes, definite joint space narrowing, some sclerosis, possible deformity. This is the cellular-therapy sweet spot. The cartilage damage is real, but the joint structure is still meaningfully intact.

Typical approach: Cellular therapy with allogeneic MSCs and exosomes, image-guided. Published response rates in this population run 60 to 70 percent at 12 months. Effect typically peaks at 6 to 12 months and persists for 12 to 24 months in responders. Maintenance dosing at 12 to 18 months is a reasonable consideration for responders.

KL grade IV (severe)

Large osteophytes, marked joint space narrowing, severe sclerosis, definite deformity. Bone-on-bone in the affected compartment.

Typical approach: Surgical consultation. Total or partial knee replacement is typically the right answer. Cellular therapy in this grade does not produce the kind of result patients want, and we won't pretend otherwise.

There are gray-zone patients between late grade III and early grade IV where the decision is genuinely close. Those are the patients where a thorough discussion of trade-offs matters most. Sometimes cellular therapy is reasonable as a bridge to delay surgery; sometimes the right answer is to proceed.

Medial vs lateral compartment disease

The knee has three compartments: medial (inner), lateral (outer), and patellofemoral (under the kneecap). Disease pattern matters for treatment.

Medial compartment dominant OA. The most common pattern. The inner compartment narrows first, often with varus (bow-legged) alignment as a contributor. Cellular therapy works well in this pattern. Partial knee replacement is also an option if disease becomes severe.

Lateral compartment dominant OA. Less common. Often associated with valgus (knock-knee) alignment. Treatment principles similar to medial.

Patellofemoral OA isolated. Pain primarily under or around the kneecap, often worse with stairs or prolonged sitting. The treatment toolkit is somewhat different; targeted injections, PT focused on quad strength and patellofemoral mechanics, and sometimes specific surgical procedures.

Tricompartmental OA. All three compartments involved. Less responsive to compartment-specific approaches; typically the population where total knee replacement is eventually the right answer.

The imaging tells us which pattern. Treatment recommendations follow.

Meniscal injury and stem cell therapy

A surprising fact for many patients: meniscal findings on MRI are extraordinarily common in middle-aged and older adults, including those with no knee pain at all. The 2008 Englund study in the New England Journal of Medicine found that about 60 percent of asymptomatic middle-aged adults had meniscal tears on MRI.

This means an MRI finding of "meniscal tear" doesn't automatically mean the meniscus is causing your pain, and surgical repair isn't automatically the right answer.

A practical framework:

Mechanical symptoms (locking, catching, giving way) with imaging of a bucket-handle tear or displaced fragment. Surgical evaluation. Cells don't fix a displaced fragment.

Acute traumatic tear in a young patient (under 40) with a repairable pattern. Surgical evaluation for meniscal repair. Some surgeons use PRP or BMAC augmentation at the time of repair.

Degenerative meniscal tear in a middle-aged or older patient without mechanical symptoms. Often does not need surgery. Cellular therapy or PRP can address the surrounding inflammation and improve symptoms without addressing the tear directly. The published literature on arthroscopic surgery for degenerative meniscal tears has not been kind to the routine surgical approach.

Meniscal tear plus moderate OA. Treat the OA. The cellular therapy or PRP addresses the inflammatory environment, the meniscal tear is often incidental, and the symptomatic response is usually meaningful.

We see a lot of patients who were told they "need" meniscal surgery for a tear that doesn't actually need surgical attention. A thorough workup separates real surgical candidates from imaging incidentalomas.

Patellofemoral pain

Pain at the front of the knee, often worse with stairs, squatting, or prolonged sitting (the "movie-goer's sign"). Common in younger patients, often related to:

Patellofemoral malalignment. The kneecap doesn't track in its groove properly. Can be due to quadriceps imbalance, Q-angle issues, or anatomic variation.

Chondromalacia patellae. Softening or wear of the cartilage under the kneecap.

Patellofemoral osteoarthritis. More established cartilage wear in the patellofemoral compartment, usually in older patients.

Patellar tendinopathy. Pain at the inferior pole of the patella, classic in athletes (jumper's knee).

Regenerative approach:

PT first and aggressively. Most patellofemoral pain responds to a structured PT program focused on hip stabilizer strength, quad mechanics, and gradual loading.

PRP for tendinopathy components, particularly patellar tendinopathy. Strong evidence base.

Cellular therapy for patellofemoral OA in the right patient, less commonly than for tibiofemoral OA.

Shockwave for chronic patellar tendinopathy. Often combined with eccentric loading programs.

Surgical consultation for refractory patellofemoral OA when conservative and regenerative options have failed.

Tendinopathies around the knee

Several tendons around the knee can become painful sources independent of intra-articular pathology:

Patellar tendinopathy (jumper's knee). Pain at the lower pole of the patella, often in athletes. PRP plus shockwave plus eccentric loading is the standard combined approach. Strong evidence base.

Quadriceps tendinopathy. Less common than patellar. Similar approach.

Distal hamstring tendinopathy. Pain at the pes anserinus or biceps femoris insertion. PRP, shockwave, and PT.

Pes anserinus bursitis. Inflammation of the bursa at the medial proximal tibia. Often responsive to corticosteroid in the short term; PRP for chronic cases.

Iliotibial band syndrome. Lateral knee pain in runners and cyclists. Primarily a PT and mechanics issue, occasionally responsive to PRP at the lateral femoral condyle.

The point: not all knee pain is joint pain. The exam often pinpoints a specific tendon as the dominant source, and the protocol changes accordingly.

The expected response: what you should plan for

Some realistic numbers for the most common cellular therapy candidate (KL grade II to III knee OA):

Procedure day. 60 to 90 minutes total: check-in, brief exam to confirm side and indication, image-guided injection (5 to 10 minutes of needle time), 30 minutes of post-procedure monitoring.

Days 1 to 3. Mild to moderate soreness in the treated joint. Some patients have a brief flare of joint pain or stiffness at 24 to 72 hours that resolves on its own. Acetaminophen and ice. No NSAIDs for 5 days.

Week 1. Most patients are walking normally and back to baseline daily activity within 3 to 5 days. We restrict high-impact activity (running, jumping, heavy lifting) for the first week.

Weeks 2 to 4. Most patients return to most normal activity. We continue to restrict high-impact loading; light cardio, swimming, cycling, and most weight-bearing activity is fine.

Weeks 4 to 6. Some patients start to notice symptomatic improvement. This is the "are we onto something" window.

Weeks 6 to 12. Improvement deepens. Most responders are clearly better by 12 weeks. We do a formal re-evaluation visit at 12 weeks with pain and function scores documented.

Months 4 to 6. Continued improvement. Many patients hit their best functional status in this window.

Months 6 to 12. Peak effect. Re-evaluation at 12 months to decide whether maintenance is appropriate.

Months 12 to 24. Effect persists in most responders. Some begin slow regression toward baseline; some continue to do well without further intervention.

If you're not responding by 12 weeks, we re-evaluate. Sometimes the right answer is a maintenance or boost dose; sometimes the right answer is to acknowledge that the protocol didn't work for you and consider alternatives, including surgical consultation.

What does not respond well

A few patient profiles where we typically counsel against cellular therapy or recommend against it:

End-stage osteoarthritis (KL IV). Bone-on-bone, severe deformity, near-zero joint space. Replacement.

Severe varus or valgus malalignment. The mechanics are working against the biology. Sometimes addressed surgically (osteotomy) before regenerative consideration is reasonable.

Significant unaddressed mechanical pathology. Bucket-handle meniscal tears, displaced fragments, frank ACL deficiency. Address the mechanical problem first.

Undiagnosed inflammatory arthritis. Treat the underlying systemic disease first; intra-articular cells don't address rheumatoid or psoriatic arthritis at the disease level.

Recent intra-articular infection. Wait until cleared.

Active cancer with metastatic risk. Careful evaluation; cellular therapy may or may not be appropriate depending on the specific cancer history and current status.

The surgical alternatives

For patients who are appropriate surgical candidates, several options exist depending on the disease:

Arthroscopy with meniscal repair or debridement. For specific meniscal pathology in younger patients.

Cartilage repair procedures. Microfracture, OATS, MACI. For focal chondral defects, usually in younger patients.

High tibial osteotomy. For younger patients with isolated medial compartment disease and varus alignment. Realigns the load away from the diseased compartment.

Partial (unicompartmental) knee replacement. For isolated single-compartment disease in patients otherwise too young for total replacement.

Total knee replacement. The definitive answer for tricompartmental, severe osteoarthritis.

Patellofemoral replacement. For isolated patellofemoral OA in the right patient.

Each has its own indications, risks, and recovery timeline. We coordinate with orthopedic surgeons we trust when surgical consultation is the right next step. (More on this in our regenerative therapy and surgery guide.)

Combination protocols

For some patients, we sequence multiple modalities:

Shockwave priming before cellular injection. For chronic refractory cases with significant peri-articular soft tissue contribution. Shockwave course 2 to 4 weeks before the cellular procedure.

PRP for soft tissue plus MSC for the joint. Patients with both tendinopathy and OA. Sequenced injections targeting different structures.

Cellular injection plus IV systemic protocol. For patients with systemic inflammatory contributors to local disease.

PT integration throughout. Regardless of the regenerative approach, we recommend a structured PT program for most knee patients. The biological effect of the procedure is amplified when paired with appropriate loading and strengthening.

What to expect at the consultation

A typical knee consultation at Apex runs 60 to 90 minutes:

History (20 to 25 minutes). Exam (10 to 15 minutes). Imaging review with you in the room (15 to 20 minutes). Discussion and written plan (15 to 20 minutes).

You leave with a written treatment plan documenting the diagnosis, the recommended protocol, the expected outcome, the cost, and the criteria for success and failure. You take the plan home and decide. Treatment, if you choose to proceed, is scheduled separately, usually 2 to 4 weeks later.

(More in our first consultation guide.)

Specific patient profiles

The 52-year-old recreational runner with moderate medial-compartment OA. Typical cellular therapy candidate. Goal: maintain running and golf for the next decade. Realistic expectation: 12 to 24 months of meaningful improvement, with maintenance dosing considered.

The 68-year-old with bilateral knee pain, varus alignment, severe imaging. Surgical conversation first. Cellular therapy not the right tool for this picture.

The 38-year-old with patellofemoral pain and recreational sports goals. PT-focused approach, possibly PRP for patellar tendinopathy if present, cellular therapy rarely the right first answer.

The 60-year-old with one meniscal tear on MRI and moderate OA. Treat the OA with cellular therapy if grade III, PRP if grade II. The meniscal tear is usually incidental and doesn't drive the protocol.

The 45-year-old high-intensity athlete with persistent post-injury knee pain after a year of conservative care. Workup carefully; protocol depends on what's actually found. Often a mixed picture (cartilage defect plus soft tissue) requiring a sequenced approach.

The 72-year-old with multi-joint involvement and morning stiffness. Screen for inflammatory arthritis before any regenerative recommendation. The picture may be rheumatologic rather than purely degenerative.

What you can do before your consultation

Get imaging together if you have it. MRI is most informative; weight-bearing X-rays add useful information about joint space and alignment. If you don't have recent imaging, we'll order it.

Write your goal in one sentence. "I want to get through the back nine without my knee killing me" is more useful than "I want my knee to feel better."

List what you've tried. PT, injections, medications, braces. Including the things that didn't help.

Bring a second pair of ears if you can. Knee decisions often involve thinking about surgery; two listeners is better than one.

How to book

To request a consultation about your knee, request a consultation or call (972) 768-2328. We're at 2111 Kirkwood Blvd, Suite 110b, Southlake, TX 76092. We see knee patients from across the DFW metroplex and from out of state.

If you've already been quoted a protocol at another clinic and want a second opinion, bring the records. The consultation fee covers a fair second look and a written next-step recommendation.

A short note from Dr. Abdullah

Knee pain patients are the most common visit on our schedule, and the most rewarding when the protocol matches the indication. The patients who come in expecting a one-shot fix to bone-on-bone disease usually leave a little disappointed; the patients who come in with moderate OA and reasonable expectations leave with a protocol that can give them 18 to 24 good months of additional running, walking, or just normal life. The work is figuring out which group each patient belongs in. That's what the consultation is for.