Meniscal Repair: To Infinity and Beyond?
By: Steven DeFroda, M.D., M.E. and Clayton W. Nuelle, M.D., FAANA
The most common orthopaedic procedure performed is a partial meniscectomy, with most meniscal tears treated using a mere debridement or partial resection instead of a formal repair. Reasons such as severity of the tear(s), patient age or poor blood supply are justifications given for going straight to a meniscectomy; we trim and move on. Twenty minutes later it’s high fives all around and on to the next case, but is this always the answer?
When doing fracture work, we do not just dispose the comminuted fragments, so why do we do this in knee arthroscopy? We all understand the importance of the meniscus to the knee joint’s health, but that doesn’t make it technically easier to repair a significant tear. COVID-19 changed a lot, but with regards to orthopaedic education, the rise of Zoom and webinars became increasingly evident, both for trainees and attendings alike. One of the most common topics? Meniscal repair. These webinars broke down barriers and geographic constraints, allowing us to see experts in the field weigh in on how they tackle complex meniscal pathology, ultimately opening new horizons and treatment options. Bucket, root, horizontal, flap and the dreaded radial tear can be repairable! Ever since the seminal article in 1982 by Arnoczky and Warren taught us about the meniscus’s blood supply, there has been a certain dogma that the meniscus has a poor vascular supply, and thus may not heal. This study states that only 10-25% of the meniscus had blood supply. It’s important to remember that this, and most other studies looking at meniscal perfusion, involve adult meniscal tissue. A recent 2020 study that examined meniscal perfusion in neonatal meniscus found a six-fold greater meniscal perfusion in all zones of the meniscus, including centrally, compared to adult meniscus.
Additionally, our techniques and surgical technology continue to improve, now giving us better access to hard-to-reach areas of the meniscus. This allows us to address previously untreated tears, such as ramp lesions and root tears. The question continues to be, however, when do we repair and when do we debride?
At this point, most arthroscopists agree vertical peripheral tears in the red-red or red-white zones should be fixed. The same goes for root tears in patients who are appropriate surgical candidates, as biomechanical studies show the hoop fibers of the meniscus almost completely deficient with a complete root tear. The literature continues to support meniscal preservation whenever possible to maintain the knee joint’s long-term health. The challenge becomes treating more complex horizontal, and radial, tear patterns. Just because we can, does that mean we should? The early literature seems to support continually pushing the envelope. A 2022 Arthroscopy paper by Yeh et al. studied two-year outcomes of arthroscopically repairing radial lateral meniscal tears. They found that 23 of the 27 repairs healed, while only four had no healing or retear. Numerous techniques and other studies were published describing similar techniques to fix these radial tears, often using a combination of vertical and horizontal mattress stitches via all-inside or inside-out technique. A 2021 study by Kurzweil et al. showed a reoperation rate of 17.4% for horizontal meniscus repair with significant improvements in all patient-reported outcome measures. A 2022 systematic review, also published in Arthroscopy, included 19 studies and 289 knees that underwent horizontal cleavage repair. Patient-reported outcomes improved across the board with with an overall 11.7% retear rate, which is in line with other meniscal repair literature.
Patient age is often cited as a factor in whether to resect versus repair, but a 10-year outcomes study by Steadman et al. examined meniscus repair in patients younger than 40 versus patients 40 and older and showed no differences in failure rates or overall clinical outcomes. Patient-reported outcome measures were similar in both groups.
Poor blood supply is another reason often cited for reticence in performing a meniscal repair versus a meniscectomy. Multiple techniques, such as capsule trephination and rasping, intercondylar notch venting/microfracture and biologic augmentation procedures, were shown to improve the meniscus's healing capacity. In 2019, Kaminiski et al. published the results of their randomized controlled trial examining meniscal repair with intercondylar notch venting versus meniscal repair alone, with the former showing a statistically significant improvement in the rate of meniscal healing (100% versus 76%). The evidence is clear: When performing an isolated meniscus repair, we must do everything we can to maximize the biology within the joint.
Despite the fanfare and popularity at national meetings in addition to Zoom regarding the increasing interest in meniscal repair, the reality is that many meniscus tears continue to go unrepaired, either via benign neglect or partial meniscectomy. A recent database study examining trends in meniscectomy and meniscal repair from 2012-2017 found that 96.6% of all cases performed were meniscectomy; clearly, this remains an ongoing quest to change treatment patterns. There does appear to be hope, however. Wasserburger and colleagues reported on trends in meniscal repair and meniscectomy by utilizing the American Board of Orthopaedic Surgeons database from 2001-2017. Some interesting trends emerged, including a linear decrease in meniscal debridement over the study period. Meniscal repair slightly increased over the study period, with the steadiest increases occurring after 2010. Also of note is that sports medicine fellowship-trained providers were more likely to perform a repair as well as repair in patients under the age of 30 and from ages 30-50. These trends are important and signify our improvement not only in repairing the meniscus, but also in training a new generation of surgeons who are familiar and comfortable with these innovative techniques. This will hopefully continue to open the door to continued advancements in treating these complex and nuanced pathologies.
Like most areas of orthopaedics, the decision to repair or resect a meniscus should be individualized based on the specific pathology involved as well as a shared decision with the patient. It’s important to explain the differences, both in the surgical procedure and in postoperative recovery. Patients should be educated on the idea that a repair is a much larger undertaking than the “clean up” procedure their favorite athlete had that got them back to play in four-six weeks. It’s also crucial to explain that meniscal preservation, especially in younger patients, will lead to a better long-term outcome for the overall knee joint health. In our practices, we tell most patients (and especially patients under 50 years old) that even if the meniscus retears or doesn’t heal after a repair, then we are back to where we started (with minimal bridges burned), but at least we attempted to save the joint as much as possible. Certainly, this will not be the case for all patients, but for patients with acute traumatic tears and minimal-to-no evidence of osteoarthritis, a repair should be attempted whenever possible.
As the saying goes, if you shoot for the moon and miss, you still land among the stars. This may be the case with the previously classified “irreparable” meniscal tear, as the early literature on complex tear patterns shows. At least in the short term, our outcomes are strong. As we continue to improve our techniques, technology and application of biologic augmentation, we should all employ the mantra “save the meniscus,” and then soon we will truly reach to infinity and beyond.