By Marc Darrow, MD, JD
“My left knee hurts, especially when I use stairs. I had surgery years ago to repair a tear. The pain has returned and has been getting worse over the last six months.”
The first question I would ask is what was repaired. A meniscus tear, a ligament tear, and a cartilage injury are different problems. The second question is where the knee hurts now. The fact that a knee has been operated on does not establish that the old injury is responsible for every new symptom.
Pain returning years after surgery may reflect another tear, arthritis, pain around the kneecap, or a problem with the surrounding tendons and other tissues. Six months of worsening symptoms is a reason to arrange an examination rather than continue guessing from the original diagnosis.
Was the tear repaired, or was tissue removed?
Patients often use “repair” to describe any operation for a torn meniscus. However, a true meniscal repair attempts to preserve the tissue, usually by securing the tear. A partial meniscectomy removes a damaged portion. That distinction matters when discussing the knee’s condition years later.
The meniscus helps distribute load between the thighbone and shinbone. Preserving it and removing part of it are not mechanically identical procedures. A 2023 meta-analysis found that meniscal repair was associated with less progression to osteoarthritis than partial meniscectomy at approximately six years of follow-up. The comparison does not prove that surgery caused an individual patient’s arthritis or that every tear could have been repaired. (1)
The operative report can clarify which structure was treated, whether tissue was removed, and whether cartilage damage was already present. If the operation involved a ligament instead, questions about stability, reconstruction, and associated injuries become more relevant. I would not assume that this was meniscus surgery from the word “tear” alone.
Why do stairs make knee pain more noticeable?
Climbing stairs requires the knee to bend while supporting body weight. Descending also requires the thigh muscles to control the lowering movement. These tasks can expose symptoms that are less noticeable during level walking.
Pain in the front of the knee or behind the kneecap raises the possibility of a patellofemoral problem—the joint between the kneecap and thighbone. Both patellofemoral pain and patellofemoral arthritis can hurt during stair use. The American Academy of Orthopaedic Surgeons describes stair climbing as a common provoking activity in patellofemoral pain and difficulty climbing or descending stairs in patellofemoral arthritis. (2) (3)
That does not make stair pain a diagnostic test. Arthritis elsewhere in the knee, a symptomatic meniscus problem, or a painful tendon can also interfere with stairs. Whether the pain is in front, along the inner or outer joint line, or over a tender spot outside the joint helps guide the assessment.
Does returning pain mean the old repair failed?
It is one possibility, but it should not be the starting conclusion. A repaired structure can develop another injury. Degeneration can also progress in a different part of the knee. Changes in strength, activity, and joint motion can affect what the knee tolerates.
The timeline helps. A new twisting injury followed by swelling is different from gradually increasing discomfort without a specific event. A knee that gives way presents a different question from one that feels stiff or hurts only during loaded bending.
True locking also deserves a clear description. A knee that physically cannot straighten is different from one that momentarily clicks or is difficult to move because it hurts. A blocked knee may require prompt orthopedic assessment; an injection should not be presumed to solve a displaced tear or loose fragment.
The purpose of the evaluation is to identify the current problem, rather than simply label the operation a success or failure eight years later.
An MRI finding is not automatically the pain source
MRI can help assess the meniscus, ligaments, cartilage, and bone. However, a tear seen on imaging does not necessarily explain the symptoms. A population study found that meniscal abnormalities were common in middle-aged and older adults, including people without knee symptoms. (4)
That study was not specifically about previously operated knees. Its useful lesson is that imaging findings need clinical context. After surgery, the radiologist also needs to know what procedure was performed because the anatomy and appearance may have changed.
An examination can assess the location of tenderness, movement, swelling, stability, strength, and symptom-provoking activities. Weight-bearing X-rays may help evaluate arthritis; MRI may be useful when a specific soft-tissue or other problem remains in question. The appropriate test depends on what the clinician is trying to establish.
More imaging is most useful when its result could change the treatment decision. Repeating a scan without a clear clinical question may produce another description of degeneration without explaining the pain.
What can be done before considering another procedure?
Treatment depends on the diagnosis. A targeted rehabilitation program may address thigh and hip strength, movement control, mobility, and tolerance for stairs. An exercise program suitable for a painful kneecap joint may differ from rehabilitation for an unstable knee or an acute meniscus injury.
Activity adjustments can reduce repeated provocation while preserving comfortable movement. Using a handrail, temporarily reducing unnecessary stair trips, and modifying painful exercise may help while the cause is assessed. These adjustments do not replace an examination when symptoms are progressively worsening.
Medication, bracing, and weight management, when relevant, can also be discussed. The aim is to match care to the current problem rather than repeat treatments solely because they were used before surgery.
Can PRP or bone marrow concentrate help?
For selected knee conditions, these injections may be options to discuss after the pain source and alternatives are understood. Previous surgery neither guarantees benefit nor automatically rules treatment out.
PRP is prepared from a patient’s blood and contains concentrated platelets. Bone marrow aspirate concentrate contains a mixture of marrow cells and other components. It is not a purified population of stem cells grown in a laboratory.
A randomized trial involving 90 patients with mild-to-moderate knee osteoarthritis compared PRP with bone marrow concentrate. Both groups improved, without a significant difference between groups through two years. Loss of participants at later follow-up limits certainty. The findings do not demonstrate cartilage regrowth or establish that either preparation treats every cause of pain after surgery. (5)
Meniscus treatment is a separate evidence question. A 2024 systematic review of nonsurgical PRP treatment for degenerative meniscus tears included six studies and 184 patients. Clinical and imaging outcomes varied, and most studies lacked a comparison group. The review does not establish reliable healing of an old surgical repair or replacement of removed meniscus tissue. (6)
Less pain and easier stair use are meaningful outcomes. They should be distinguished from proof that cartilage or meniscus has regenerated. An injection also does not mechanically restore a torn ligament reconstruction, correct major malalignment, or remove a loose fragment.
What about Wharton’s jelly or other donor products?
Wharton’s jelly is connective tissue from a donor umbilical cord. A processed tissue product is different from PRP and from a patient’s own marrow concentrate. Its source does not establish its viable cell content, clinical effectiveness, or equivalence to another preparation.
There is not established evidence that a non-expanded Wharton’s jelly injection reliably repairs a recurrent knee tear eight years after surgery. Research using cultured cells cannot be substituted as proof for a different tissue product. FDA consumer guidance states that the regenerative medicine therapies it discusses have not been approved for orthopedic conditions. (7)
For more detail about the differences among preparations, see the site’s knee-injection comparison. Choosing an injection comes after establishing what needs treatment.
When does another surgical opinion make sense?
Another operation is not the automatic answer to returning pain. However, significant instability, a displaced tear causing true locking, a loose body, or severe joint damage may require an orthopedic discussion. The nature of the original procedure and the current examination matter.
References
- Migliorini F, Schäfer L, Bell A, Weber CD, Vecchio G, Maffulli N. Meniscectomy is associated with a higher rate of osteoarthritis compared to meniscal repair following acute tears: a meta-analysis. Knee Surg Sports Traumatol Arthrosc. 2023;31(12):5485–5495. doi:10.1007/s00167-023-07600-y.
- American Academy of Orthopaedic Surgeons. Patellofemoral Pain Syndrome. OrthoInfo. Accessed October 13, 2026.
- American Academy of Orthopaedic Surgeons. Patellofemoral Arthritis. OrthoInfo. Accessed October 13, 2026.
- Englund M, Guermazi A, Gale D, Hunter DJ, Aliabadi P, Clancy M, Felson DT. Incidental meniscal findings on knee MRI in middle-aged and elderly persons. N Engl J Med. 2008;359(11):1108–1115. doi:10.1056/NEJMoa0800777.
- Anz AW, Plummer HA, Cohen A, Everts PA, Andrews JR, Hackel JG. Bone Marrow Aspirate Concentrate Is Equivalent to Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis at 2 Years: A Prospective Randomized Trial. Am J Sports Med. 2022;50(3):618–629. doi:10.1177/03635465211072554.
- Gopinatth V, Batra AK, Chahla J, Smith MV, Matava MJ, Brophy RH, Knapik DM. Degenerative Meniscus Tears Treated Nonoperatively With Platelet-Rich Plasma Yield Variable Clinical and Imaging Outcomes: A Systematic Review. Arthrosc Sports Med Rehabil. 2024;6(2):100916. doi:10.1016/j.asmr.2024.100916.
- U.S. Food and Drug Administration. Important Patient and Consumer Information About Regenerative Medicine Therapies. FDA consumer guidance. Accessed October 13, 2026.