Abstract
Background:
All-inside meniscal repair first became popularized in the early 2000s. Since that time, there has been a wide variety of all-inside implants on the market with rapid changes and developments in recent years.
Indications:
Small, peripheral, longitudinal tears are best suited for all-inside repair, but this technique may even be used for large bucket handle tears especially when hybridized with an inside-out repair.
Technique Description:
A percutaneous release of the medial collateral ligament (MCL) with an 18-g spinal needle is frequently performed when working in the medial compartment to improve visualization and decrease risk of iatrogenic chondral injury. Close familiarity with the characteristics of the chosen all-inside device including device angle, modifiability of device angle, modifiability of needle depth, deployment method, and tensioning technique is important for obtaining reproducible results. Typically, obtaining a vertical mattress stitch configuration is optimal as it captures more circumferential collagen fibers in the repair.
Results:
Factors to consider when selecting an all-inside meniscal repair device include the ergonomics of the device, implant cost, availability, rigid versus suture-based anchor, core needle diameter, device flexibility, and percent of misfires.
Discussion:
Complications from use of all-inside meniscus repair devices include device failure, soft tissue entrapment, cyst formation, and injury to the popliteal artery. Outcomes, however, with current devices are good and comparable to inside-out meniscus repair with about a 90% return to sports rate at 12 months postoperatively.
The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.
This is a visual representation of the abstract.
Video Transcript
This video will go over all-inside meniscal repair and offer a historical overview of the topic.
The authors have the following disclosures to report.
We will start off with a discussion of the anatomy of the meniscus, discuss conditions when repair should be considered, briefly review the types of repair options out there, and discuss the technique. We will show a case presentation and discuss complications, return-to-sport criteria, and briefly review a little of the literature surrounding all-inside devices.
The medial meniscus is semicircular with widely separated anterior and posterior horns. It is wider posteriorly and firmly attached to the capsule. Conversely, the lateral meniscus is more circular with closer anterior and posterior horns. The width is similar posteriorly and anteriorly, and it is only loosely attached to the capsule.
The vascular supply to the meniscus is peripheral in the red zone. The middle geniculate provides blood supply to the posterior horns while the inferior medial and lateral geniculates provide it to the remainder of the meniscus.
The goal of meniscal repair is to preserve the function of the meniscus. It is critical for load distribution, and when the knee is in >90° of flexion, the posterior horns are particularly important. Loss of meniscal integrity leads to abnormal contact stresses precipitating degenerative changes. The speed at which this occurs is related to the amount of meniscal tissue lost.
Meniscal repair should be performed whenever possible. While complex and degenerative tears may not be repairable, others may be. Even in settings requiring a partial meniscectomy, partial repair may also be possible. The best results for repair occur in acute, peripheral, longitudinal tears in young patients with a concurrent anterior cruciate ligament (ACL) reconstruction.
Options for repair include open, inside-out, outside-in, and all-inside. Inside-out is the gold standard for meniscal repair, while outside-in is better for more anterior tears.
Meniscal repair first became popularized around the beginning of the 21st century. These utilized rigid implants such as arrows, darts, screws, and others. However, complications plagued these methods as they were very prone to failure, implant migration, and chondral damage.
Currently, there are numerous all-inside devices on the market. This can be very confusing as each company often develops a new device every few years with a new name, and these companies can be fairly dynamic. And, while they will publicize their own white papers for their product, there is actually fairly limited independent review.
These are the current companies with all-inside repair devices and the names of their devices.
Arthrex developed the Meniscal Cinch in 2015 and iteration 2 in 2018. These had PEEK anchors. They currently have the FiberStitch with 4 different available angles. Their white paper notes it is stronger than the Fast-Fix and the JuggerStitch.
The Conmed Sequent came on the market in 2016 and is notable in that it allows multiple passes.
DePuy-Mitek’s most recent device on the market is the TrueSpan with PEEK and PLGA anchors, 3 different angles for the device, and a trigger to enhanced ergonomic use.
Smith and Nephew produced the original all-inside device. They have had multiple iterations and developments in their devices. Their most recent is the Fast-Fix Flex released in 2021 which allows the user to customize the angle of the implant by bending the needle and/or the shaft.
Stryker’s device is the Air+ which has a flexible needle allowing customization and an ergonomic plunger design.
Zimmer Biomet has had a number of offerings over the years. The JuggerStitch is an all-suture anchor while the Cross Fix 2 allows the creation of a mattress stitch with a single pass.
With so many offerings, there are a number of factors for surgeons to consider. These include the company and equipment reps, ergonomics of the device, implant cost, availability, rigid versus suture-based anchor, core needle diameter, device flexibility, and the percent of misfires.
Ideally, all-inside repairs are meant to mimic inside-out repairs by creating a vertical mattress-type suture configuration, as this grabs the greatest number of circumferential meniscal fibers. However, specific situations may require the use of a more oblique or even horizontal configuration.
Our patient is a healthy 21-year-old female who experienced a noncontact, pivoting injury to the left knee during a lacrosse game. She did not immediately seek care, and 3 weeks later she experienced another pivoting injury while walking down a hill resulting in an inability to achieve full knee extension. She did not have a history of prior injury to this knee.
Her range of motion (ROM) on examination was 10-125. Her effusion had resolved. However, she had medial joint line tenderness with a positive McMurray sign. She had a grade 2b Lachman. A pivot shift was unable to be performed secondary to guarding. She was otherwise ligamentously stable.
Her magnetic resonance imaging (MRI) showed a bucket handle meniscus tear with a double posterior cruciate ligament (PCL) sign.
She had a complete tear of her ACL. On coronal imaging, the flipped bucket handle meniscal fragment was seen in the notch. She was consented for a left knee ACL reconstruction with bone-patellar tendon-bone autograft with a medial meniscus repair.
After a diagnostic arthroscopy, the bucketed meniscus is reduced with an arthroscopic probe. Next, the medial collateral ligament (MCL) is percutaneously released with an 18-g spinal needle just proximal to the joint line. This allows better visualization during meniscal repair and minimizes the chance of iatrogenic chondral injury.
The first device used here is the Arthrex FiberStitch. It allows adjustment of needle depth via the button proximal to the shaft, and it is triggered using the wheel on the handle of the device. After the location of the stitch is selected, the needle is placed through the tissue and the device is deployed by rolling the wheel fully backward and then forward. A click should be heard. The second location for the mattress stitch is selected, and the same sequence is repeated.
The device is removed from the knee yielding a free end and a loop outside the knee. While holding the free end, the stitch is tensioned by pulling on the loop. The knot is finalized by pulling on the free end. An arthroscopic cutter is used to cut the suture.
The Mitek TrueSpan is similar in that it has a way to adjust the needle depth, but it has a trigger firing mechanism. When firing the TrueSpan, there is some rebound so it is important that the surgeon maintains forward pressure while pulling the trigger.
In good tissue, the knot may be tensioned by pulling on the free suture. In poorer tissue, an arthroscopic probe may provisionally tension the stitch by pulling on one of the loops and then finally tightened by pulling the free stitch.
This is the final repair using a combination of all-inside and inside-out stitches.
The success of the operation begins with proper portal placement. Localizing working portal placement with a spinal needle can be helpful to ensure a good trajectory for the repair device. Poor portal placement can compromise the repair or result in device bending and misfires. Gently preparing the surfaces of the torn meniscus either with a rasp or careful debridement with the shaver can remove granulation tissue and help with healing. Device misfires can be frustrating and expensive. Familiarity with the device is the best way to minimize this risk.
In addition, many devices have some rebound when the anchor is deployed. Maintaining forward pressure while firing helps to counteract this. Biologic adjuncts such as notch microfracture, fibrin clot, bone marrow aspirate concentrate, and platelet-rich plasma may be used. However, there still remains some debate in the literature on the absolute benefit these provide.
Complications of all-inside meniscal repair include device failure, including situations in which this goes unrecognized and results in the anchor in the joint functioning as a loose body. There can be soft tissue entrapment such as incarceration of the popliteus tendon or the superficial MCL. There is up to a 40% rate of cyst formation after all-inside repair. In addition, the popliteal artery courses directly posterior to the posterior horn of the lateral meniscus and can be susceptible to the needle on all-inside devices particularly when the anterolateral portal is used aiming for the posterior horn of the lateral meniscus.
The literature on all-inside repairs shows overall good results. The MRI follow-up at >4 years shows that while there are good clinical results, there is still some signal in up to 70% and complex tearing in 20% of cases. There is up to a 17% failure rate at an average 9-month follow-up. However, in a systematic review, no difference was noted between inside-out repairs and all-inside repairs, and 90% of patients are able to return to sports at 12-month follow-up.
Our typical progression for a patient is 50% weight bearing and ROM 0 to 90 for the first 6 weeks with therapy focusing on quad strengthening. The next 4 weeks we progress them in weight bearing and to full ROM with a focus on closed-chain strengthening. After 10 weeks, we begin running, plyometrics, and cutting activities. We then introduce and progress sports-specific activities with return to sports when they are able to complete these.
In conclusion, all-inside repair works well if used judiciously. It is very good for small tears especially with concomitant ACL reconstruction. It may be used in a hybrid technique with inside-out fixation for large bucket hand tears and meniscal allograft transplantation although it should not be used in isolation for these procedures. In addition, all-inside repairs should be avoided in the revision setting in favor of an inside-out repair. There is also promise for the more recent suture anchor implants as they avoid some of the compilations of older implants though there is need for further biomechanical study on these.
We thank you for watching this video.
Footnotes
Submitted May 26, 2022; accepted July 21, 2022.
The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
