During a total knee replacement, both menisci are removed entirely as part of the procedure, so in the strict sense you cannot tear a meniscus that is no longer in your knee. The surgery replaces the natural joint surfaces with metal and plastic components, and the meniscal cartilage is excised to make room for these implants. That said, there are real and documented exceptions involving remnant tissue, regrown tissue, and a separate category of partial knee replacements where a meniscal tear absolutely can happen. If you are experiencing clicking, locking, or new pain after knee replacement surgery, the explanation is almost certainly something other than a classic meniscal tear, but that “almost” matters.
Why the Menisci Are Removed During Total Knee Replacement
A total knee replacement, sometimes called total knee arthroplasty or TKA, involves resurfacing three compartments of the knee: the inner (medial) side, the outer (lateral) side, and the area behind the kneecap. The surgeon removes damaged cartilage and a thin layer of bone from the end of the thighbone and the top of the shinbone, then fits metal components over those surfaces. A plastic spacer sits between the metal parts, acting as the new gliding surface. Because this plastic insert occupies the space where the menisci used to sit and the bony surfaces they attached to have been reshaped, the menisci have no structural role left. Surgeons routinely excise them to ensure proper fit and alignment of the implant.
This is a key distinction from other knee surgeries. If you’ve had an ACL reconstruction or a cartilage repair, your menisci are still in place and can absolutely be injured later. After a total knee replacement, that particular worry is essentially off the table. But “essentially” is not “completely.”
When Leftover Meniscal Tissue Causes Trouble
Surgeons aim to remove the menisci completely, but small fragments can occasionally be left behind, particularly from the posterior horns (the back portions) that are harder to access during surgery. In one documented case, a trapped remnant of the posterior horn of the medial meniscus became wedged against the plastic insert after TKA, causing severe early wear of the polyethylene component. The impingement was significant enough that it led to premature failure of the insert and required reoperation.1PubMed Central. An impinging remnant meniscus causing early polyethylene failure in total knee arthroplasty: a case report
Even more unusually, meniscal tissue can actually regenerate after being removed. The body sometimes grows new fibrous tissue in the space where the meniscus used to be, and if that tissue gets caught between the implant components, it creates pain that feels a lot like a meniscal problem in a natural knee. One reported case involved a patient whose chronic pain on both the inner and outer sides of the knee turned out to be caused by regenerated meniscal tissue that had become entrapped. The problem was successfully treated with arthroscopic surgery to clean out the regrown tissue.2PubMed Central. Meniscal Regeneration: A Cause of Persisting Pain following Total Knee Arthroplasty
These cases are genuinely rare, but they’re worth knowing about because they represent situations where a meniscal-type problem really does occur after total knee replacement. If you’re told “it can’t be your meniscus,” these documented exceptions show that blanket reassurance isn’t always accurate.
Partial Knee Replacement Is a Different Story
This is where confusion often creeps in. A unicompartmental knee arthroplasty, commonly called a partial knee replacement, resurfaces only one compartment of the knee, usually the medial side. The rest of the knee, including the meniscus in the untouched compartment, remains intact. That surviving meniscus is just as vulnerable to tearing as it was before surgery.
In one case report, a patient developed a lateral meniscal tear after a successful medial unicompartmental knee replacement. The tear presented as unexplained joint-line pain on the unoperated side, and it was initially attributed to degenerative changes progressing in the lateral compartment. Once the meniscal tear was correctly diagnosed, an arthroscopic partial meniscectomy resolved her symptoms entirely.3PubMed. Lateral meniscal injury after a successful medial unicompartmental knee arthroplasty The case highlights a diagnostic pitfall: surgeons and patients alike may assume that new pain after a partial replacement means the arthritis is spreading, when the actual culprit is a straightforward meniscal tear in the preserved compartment.
If you’ve had a partial knee replacement and develop new pain on the side that wasn’t operated on, a meniscal tear should be on the differential list. This is an important practical takeaway, and one reason it matters to know exactly what type of knee replacement you received.
What Actually Causes Meniscus-Like Symptoms After Total Knee Replacement
Clicking, catching, locking, and sharp pain along the joint line are the classic signs of a meniscal tear in a natural knee. After TKA, those same symptoms can appear for entirely different reasons. The mechanical environment of an artificial knee creates its own set of problems that can feel deceptively similar.
Patellar Clunk Syndrome
One of the better-known causes of mechanical symptoms after TKA is patellar clunk syndrome, which occurs most often with posterior-stabilized implant designs. A fibrous nodule forms where the upper edge of the kneecap meets the quadriceps tendon, and it catches in the implant’s intercondylar notch as the knee straightens. The result is a painful, audible clunk that patients sometimes describe as something “catching” inside the knee. Symptoms range from mild crepitus to a frank clunk that disrupts walking.
Scar Tissue and Arthrofibrosis
Excessive scar tissue formation inside the joint, known as arthrofibrosis, is one of the more common reasons for persistent stiffness and pain after TKA. Dense adhesions can restrict motion and create a sensation of tightness or locking that mimics internal derangement. When conservative treatment like physical therapy fails, arthroscopic removal of scar tissue can improve range of motion and reduce pain. In one series, patients who underwent arthroscopic adhesion release improved their functional scores meaningfully and gained additional range of motion.4PubMed Central. Arthroscopic arthrolysis for arthrofibrosis of the knee after total knee replacement
Loose Bodies and Soft-Tissue Impingement
Small fragments of bone cement, polyethylene debris, or hypertrophied synovial tissue can float freely in the joint or become wedged between components. These loose bodies cause intermittent locking and sharp pain that feels exactly like a torn meniscus would in a natural knee. Arthroscopic surgery can remove these fragments and debride any impinging tissue.5PubMed Central. Arthroscopic lysis of adhesions for the stiff total knee arthroplasty
Component Problems
Loosening of the metal components from the underlying bone, wear of the plastic insert, or instability of the joint can all produce symptoms that overlap with what a meniscal tear would feel like. In mobile-bearing TKA designs, where the plastic insert is designed to rotate on the tibial tray, there is a small risk of the insert spinning out of position or dislocating entirely. One large series found this happened in roughly 0.3% of cases, most often within the first six months and more commonly in patients whose knees had a valgus (knock-knee) alignment before surgery.6PubMed. Spinout/Dislocation in Mobile-Bearing Total Knee Arthroplasty: A Report of 26 Cases A dislocated bearing insert causes sudden pain, instability, and mechanical symptoms that are impossible to ignore.
Extra-Articular Sources of Pain
Not all post-TKA pain originates inside the joint. Bursitis around the knee, tendon irritation, and even polyethylene debris migrating into surrounding soft tissues can produce symptoms that seem joint-related but actually come from outside the prosthesis. In one unusual case, polyethylene particles caused chronic bursitis of the pes anserinus (a group of tendons on the inner side of the knee), creating draining skin lesions that initially mimicked an infected joint replacement.7PubMed. Polyethylene-induced pes anserinus bursitis mimicking an infected total knee arthroplasty: a case report and review of the literature
How Surgeons Figure Out What’s Wrong
Diagnosing the cause of pain after TKA is genuinely challenging. The metal components create artifacts on standard imaging that obscure the very structures surgeons need to see. X-rays can reveal gross loosening or malalignment but miss soft-tissue problems entirely. MRI, long the gold standard for evaluating meniscal tears in natural knees, has historically been limited around metal implants, though advances in metal artifact reduction sequences over the past decade have made MRI much more useful for assessing soft tissues, infection, component loosening, and polyethylene wear around knee replacements.8PubMed. Magnetic resonance imaging evaluation of the painful total knee arthroplasty
Hybrid nuclear medicine imaging, which combines a bone scan with CT, has shown particular promise. In one study of patients with painful TKAs, this type of imaging changed the suspected diagnosis and the proposed treatment plan in the vast majority of cases, identifying problems like patellofemoral arthritis progression and component loosening that had been missed or misattributed.9PubMed Central. Clinical value of SPECT/CT for evaluation of patients with painful knees after total knee arthroplasty–a new dimension of diagnostics? The takeaway for patients: if your surgeon can’t pinpoint the cause of your post-TKA pain with standard tests, more specialized imaging exists and is worth asking about.
The Role of Arthroscopy After Knee Replacement
When imaging and clinical examination point to a soft-tissue problem inside the replaced knee, arthroscopy can serve as both a diagnostic and therapeutic tool. A camera is inserted through small incisions to visualize the interior of the joint, allowing the surgeon to identify and treat problems like scar tissue, loose bodies, impinging soft tissue, and fibrous nodules in the same procedure.
A retrospective study examining arthroscopy for common soft-tissue complications after TKA found that patients generally improved in range of motion and functional scores. Range of motion increased from about 82 degrees to 97 degrees on average, and both pain and function scores improved significantly. However, the study also reported a symptom recurrence rate of about 23% and a prosthesis revision rate of roughly 15%, meaning arthroscopy doesn’t always provide a lasting fix and some patients ultimately need more extensive revision surgery.10PubMed Central. The role of knee arthroscopy in managing common soft tissue complications after total knee arthroplasty: a retrospective case series study
For the specific scenario of remnant or regenerated meniscal tissue causing impingement, arthroscopic debridement has been reported to resolve symptoms effectively. But arthroscopy around a prosthetic knee is not without risk. The same study noted postoperative complications including periprosthetic joint infections, a serious concern in any surgery involving an artificial joint. The decision to scope a replaced knee is not taken lightly.
When a Tibial Insert Needs Replacing
If the plastic insert between the metal components has been damaged by impinging tissue, wear, or a mechanical problem, an isolated tibial insert exchange may be an option. This involves opening the knee to swap out the worn plastic spacer without removing the metal components from the bone. A large single-institution review of 270 such exchanges performed over three decades found that the procedure was reliable and durable when the underlying cause was polyethylene wear. When the cause was instability, insert fracture, or stiffness, the results were less consistent.11PubMed. Isolated tibial insert exchange in revision total knee arthroplasty The most common reason for these exchanges was instability, followed by wear. This matters because the cause of the problem shapes the expected outcome: a straightforward worn-out insert tends to do well with a swap, while instability often signals a deeper alignment or ligament issue that a new insert alone won’t fix.
Pain After Knee Replacement and What Patients Expect
Chronic pain after total knee replacement is more common than many patients anticipate. Studies consistently find that a meaningful minority of TKA patients report persistent pain that they did not expect, even when imaging shows a well-positioned, well-functioning implant. In a review of malpractice claims after primary TKA, chronic pain or dissatisfaction was the single most frequent factor leading to lawsuits, ahead of nerve injuries, postoperative falls, and blood clots.12Journal of the American Academy of Orthopaedic Surgeons. Lawsuits After Primary and Revision Total Knee Arthroplasty: A Malpractice Claims Analysis
This doesn’t mean the surgery failed or that something was done wrong. It reflects the reality that an artificial knee is not a biological knee, and some patients experience discomfort that has no clear structural explanation. When patients search for a specific cause like a meniscal tear, they’re often trying to make sense of pain that feels like it should have a fixable source. Sometimes it does, and the sources described above, from remnant tissue to scar adhesions to bearing problems, are all real and treatable. Other times, the pain is more diffuse and resistant to a single diagnosis.
Meniscal Scaffolds and the Future of Preservation
While not directly relevant to someone who already has a total knee replacement, the broader landscape of meniscal treatment is worth knowing about, especially if you’re earlier in the process and considering your options. For patients who have lost meniscal tissue but haven’t yet progressed to needing a full joint replacement, synthetic meniscal scaffolds offer a middle-ground approach. These implants provide a structural framework that encourages native tissue to grow into the scaffold over time. Two partial meniscal scaffolds are currently in clinical use, and a total meniscal replacement device also exists, with several others in preclinical testing.13PubMed Central. Synthetic meniscus replacement: a review
Meniscal allograft transplantation, where a donor meniscus is surgically implanted, is another option for select patients, though long-term failure rates are not trivial, with some studies showing rates approaching 55% at ten years. For many patients, the goal of these procedures is to delay or avoid the need for knee replacement rather than to eliminate it entirely. The technology is evolving, and newer scaffold designs aim to better replicate the complex biomechanics of the natural meniscus.14Journal of Cartilage & Joint Preservation. Current state of off the shelf scaffolds and implants for meniscal replacement
None of these options are applicable once a total knee replacement has been performed, because the joint architecture has been fundamentally altered. But they underscore why meniscal preservation earlier in the disease process matters: once the menisci are gone and the joint has deteriorated enough to require TKA, the biological clock can’t be wound back.