Popliteal neurovascular bundle is safe during inside-out repair of medial meniscus without a safety incision

Risk of Iatrogenic Peroneal Nerve Injury in Inside-Out Lateral Meniscal Repairs Using Differently Curved Repair Devices and Surgical Portals

Background: Inside-out meniscal repair is a widely adopted treatment for lateral meniscal injuries. A significant complication associated with this procedure is iatrogenic peroneal nerve (PN) injury, reported in approximately 9% of cases. The risk varies depending on the choice of surgical portals, curvature of repair devices, and anatomical landmarks. This study aimed to assess the risk of PN injury and define safe zones for inside-out lateral meniscal repair using different device curvatures and portal combinations. Methods: Axial MRI scans of knees positioned in the figure-of-four posture, with joint fluid distension and varus force applied, were analyzed in 29 adult patients. Transparent overlays representing the operative routes of the anterior-, middle-, and posterior-curved needles were superimposed on the MRI scans. Simulations of repair procedures were performed using the anteromedial, accessory anteromedial, anterolateral, and accessory anterolateral portals, targeting the medial and lateral borders of the popliteus tendon (PT). Instances where the needle path intersected or contacted the PN were recorded to delineate risk zones. Results: Repairs targeting the medial PT border with anterior-curved devices via the anteromedial or accessory anteromedial portals were identified as safe. At the lateral PT border, all device curvatures and portals were considered safe, except for middle- and posterior-curved devices used through the accessory anteromedial portal, which posed a risk of PN injury. Conclusions: The risk of iatrogenic PN injury in inside-out lateral meniscal repair depends on the curvature of the repair device and portal used. Adhering to the identified safe zones can substantially reduce this risk.

Identifying Risk Zones for Neurovascular Injury in Pediatric All-Inside Arthroscopic Lateral Meniscal Repair

Background

All-inside techniques for meniscal repairs offer comparable outcomes and healing rates with reduced operative time and fewer incisions; however, iatrogenic neurovascular injuries during arthroscopic meniscal repairs are a significant concern.

Purpose

To identify the zones of risk and incidence of injury concerning the common peroneal nerve (CPN) and popliteal artery in relation to the popliteal tendon (PT) from the anterolateral (AL) and anteromedial (AM) portals during a simulated all-inside technique in the pediatric population.

Study Design

Descriptive laboratory study.

Methods

Using axial knee magnetic resonance imaging scans of 124 patients, the all-inside technique was simulated by drawing direct lines from the AM and AL portals to the medial and lateral borders of the PT. If the line came into contact with the CPN, a risk of projected iatrogenic CPN injury was found. Measurements were then recorded to assess and define "risk zones." A similar simulation was performed in relation to the popliteal artery to assess distance to projected iatrogenic injury.

Results

The risk of CPN injury was significantly higher when using the AL portal (45%) compared with the AM portal (19%) when simulating repair at the lateral edge of the PT (P < .001). Similarly, there was a significantly higher risk of peroneal nerve injury when using the AM portal (29%) compared with the AL portal (8.9%) when simulating repair from the medial edge of the PT (P < .001). The risk of injury when repairing the body of the lateral meniscus through the AM portal extended 2.20 ± 0.98 mm laterally from the lateral edge of the PT and 3.14 ± 1.92 mm medially from the medial edge of the PT. The risk of injury when repairing the body of the lateral meniscus through the AL portal extended 2.58 ± 1.31 mm lateral to the lateral edge of the PT and 2.02 ± 1.61 mm medial to the medial edge of the PT.

Conclusion

The authors found that the AM portal was safer for repairing the body of the lateral meniscus while simulating repair at the lateral edge of the PT, while the AL portal was safer for repairing the lateral meniscus while simulating repair from the medial edge of the PT.

Clinical Relevance

By understanding these risk profiles, surgeons can adopt safer approaches for meniscal repairs in pediatric patients, thereby minimizing the likelihood of injuring sensitive neurovascular structures.

Combined Procedure of Arthroscopic Pullout Medial Meniscal Root Repair From Lateral Tibia and Open-Wedge Distal Tibial Tubercle Osteotomy

Pullout repair of medial meniscal posterior root tears (MMPRTs) is generally recommended for patients with well-aligned knees, whereas open-wedge high tibial osteotomy (OWHTO) is often recommended for patients with MMPRTs and varus osteoarthritis. Although the management of MMPRTs with OWHTO has been controversial, retaining meniscal function can be expected through pullout repair. Conventionally, bone tunnels in pullout repair are created from the proximal anteromedial tibia. However, this technique could cause a killer angle of the repaired meniscus and could have a risk of turning the guidewire toward the neurovascular band. Therefore, we create a bone tunnel from the proximal anterolateral tibia combined with open-wedge distal tibial tubercle osteotomy, which can prevent an increase in postoperative patellofemoral contact stress; moreover, the bone tunnel can be created easily from the lateral tibia compared with OWHTO. This Technical Note describes the combined surgical procedure for patients with MMPRTs and varus osteoarthritis, which has advantages including physiological pullout direction of the repaired meniscus, lower risk of neurovascular damage, and placement of a longer plate screw that could interfere with the bone tunnel. We highlight the meticulous consideration given to the interference of the bone tunnel between the osteotomy line and plate screw.

Single-incision bone bridge lateral meniscus allograft transplantation: preserving neurovascular safety with promising results for posterior horn distortion and graft maturation

PURPOSE

This study aimed to investigate the graft maturation and safety of single-incision bone bridge lateral meniscus allograft transplantation (LMAT).

METHODS

This study involved 35 patients who underwent LMAT between 2019 and 2020. All patients completed at least 2 years of follow-up (median 34 months; range 24-43) and underwent preoperative magnetic resonance imaging (MRI) to assess the trajectory safety of the leading suture passer and all-inside suture instrument (Fast-Fix). Graft status was evaluated according to the Stoller classification.

RESULTS

Based on preoperative MRI measurements, the expected trajectory of the leading suture passer did not transect the common peroneal nerve (CPN), with the closest distance between the expected trajectory and CPN being 1.4 mm and the average distance being 6.8 ± 3.2 mm. The average distance from the lateral meniscal posterior horn (LMPH) to the popliteal neurovascular bundle (PNVB) was 7.4 ± 2.6 mm and the nearest was 4.8 mm. The expected trajectory of the all-inside suturing instrument did not transect the PNVB when the distance was at least 12 mm, from the most lateral margin of the posterior cruciate ligament (PCL). Grade 3 signal intensity in the posterior third of the allograft on MRI was observed in 6 of 35 (17.1%) patients. Amongst the grade 3 signal intensities in the posterior one-third of the allografts, 3 of the 35 (8.5%) LMATs had a distorted contour.

CONCLUSION

The single-incision bone bridge LMAT technique introduced in this study is a convenient approach that preserves neurovascular safety and provides good results for the distortion of the posterior horn of the allograft and graft maturation. The safety zone for the penetrating devices during the procedure extended from 12 mm laterally to the most lateral margin of the PCL to the medial margin of the popliteal hiatus.

LEVEL OF EVIDENCE

IV.

LARAI portal provides a safe method for lateral meniscus repair: three-dimensional computed tomography and cadaveric assessment

BACKGROUND

Lateral, All-Round and All-Inside (LARAI) portal is a viewing or working portal for observing and repairing the lesions of the lateral meniscus. However, there are safety concerns about popliteal artery (PA) injuries during the procedure. This study aimed to assess the safe distance between the trajectory of the LARAI portal and PA.

MATERIALS AND METHODS

Both three-dimensional computed tomography (3D-CT) and cadavers were used to simulate the LARAI portal trajectory. In the 3D-CT study, between January 2020 and September 2020, 45 participants who underwent computed tomography angiography were included in the study. The shortest distance from the PA to the simulated trajectory needle (PS) was measured using 3D-CT. Mean -3SD -2 was calculated to assess the safety of the LARAI portal trajectory. If this value was more than zero, the trajectory was considered "safe." In the cadaveric study, lower limbs from seven fresh-frozen cadavers were used to establish the "safe" trajectories of the LARAI portal, and the PS was measured.

RESULTS

In the 3D-CT study, the longest PS (P < 0.001) was found 20 mm lateral to the edge of the patellar tendon trajectory at 0 mm from the posterior cruciate ligament (PCL). Safe trajectories were also found 10 mm, 15 mm, and 20 mm lateral to the edge of the patellar tendon at 0 mm from the PCL, as well as the 20 mm lateral to the edge of the patellar tendon at 3 mm from the PCL. The cadaveric study showed that the average PS of all safe trajectories closely adjoined to PCL was greater than 14 mm.

CONCLUSIONS

The LARAI portal trajectory in the "figure of four" is safe, and the optimal insertion point is 10-20 mm lateral to the edge of the patellar tendon and closely adjoined to the posterolateral margin of the PCL at knee joint line level.

LEVEL OF EVIDENCE

Level IV.

Using a Combined All-Inside, Inside-Out, and Outside-In Technique to Repair Bucket-Handle Medial Meniscal Tears Without a Safety Incision

We describe a combined all-inside, inside-out, and outside-in technique for the repair of unstable bucket-handle medial meniscal tears. Notably, a greater incidence of neurovascular complications has been associated with meniscal repair techniques that employ an accessory skin incision, especially when damage involves the body of the medial meniscus. However, with the operative knee in relative extension, passing inside-out needles anteromedial to the posterior horn and posterior to the semitendinosus tendon and saphenous nerve allows for the needles to exit the posteromedial knee through a "safe zone." Therefore, we reduce iatrogenic damage by avoiding the necessity of a large safety incision while still maintaining suture placement versatility and meniscal fragment stabilization. Thus, the objective of this Technical Note is to outline an efficient technique for treating bucket-handle medial meniscal tears that yields a strong, durable repair while avoiding damage to adjacent neurovascular structures and eliminating the need for a posteromedial safety incision.

The Popliteal Artery is Safe in Medial Meniscal Repair Using All Inside Devices in Adults: An MRI-Based Simulation Study

Introduction

This simulation study on MRI of the knee was performed to assess the risk of injury to the popliteal artery (PA) and common peroneal nerve (CPN) during all-inside meniscal repairs in adults.

Methods

We simulated repair of the posterior horn of both medial (PHMM) and lateral menisci (PHLM) through anteromedial (AM) and anterolateral (AL) portals, using straight and curved devices, on 200 magnetic resonance imaging (MRI) scans taken with the knee in extension. For simulation using straight devices, the shortest distance from the menisco-capsular junction (MCJ) and the free edge of the meniscus to PA and CPN in vectors of AM and AL portals was measured. In curved devices, the closest extracapsular distance from the device tip to PA was measured.

Results

With a straight device through AM portal, the mean distance from the MCJ of PHMM to the PA was 20.7 ± 3.15 mm (13.5-27.4). In PHMM repair through AM portal using a curved device, the mean extracapsular distance from the device tip to PA was 18.8 ± 4 mm (7.7-27.2) while pointing toward and 26 ± 4.5 mm (15.5-35.6) while pointing away from the midline. When using straight devices, the average distance from free edge of LM to PA was 18.5 ± 3.3 mm (9.6-31.2) and from MCJ to PA was 8.9 ± 2.4 mm (3.5-18.8). The average distance measured from the MCJ to CPN through AM and AL portals using straight devices was 19.4 ± 2.8 mm (10.2-32.5) and 22 ± 2.8 mm (10.4-36.7) respectively.

Conclusion

In adults, PA is safe in PHMM repairs using both straight and curved devices irrespective of depth and direction of insertion. In PHLM repairs, the PA is at risk with both straight and curved devices. We recommend adjusting the depth of insertion to as minimum as possible to just penetrate the capsule. The CPN is safe in LM repairs using all-inside devices.

Level of Evidence

Level IV.

Ultrasound-Assisted Arthroscopic All-Inside Repair Technique for Posterior Lateral Meniscus Tear

Arthroscopic repair of the posterior horn of the lateral meniscus (LM) from an anterolateral portal has a risk of popliteal artery injury. Here, we present an ultrasound-assisted, arthroscopic, all-inside repair technique for a posterior LM tear to reduce the risk of neurovascular injury. An ultrasound probe covered with a sterile sleeve is placed horizontally at the popliteal fossa by an assistant surgeon, and the popliteal artery and posterior LM are confirmed. From the anterolateral portal, an arthroscopic probe is inserted to push the posterior capsule of the lateral compartment, while an ultrasound image detects the tip of the probe. After the probe is confirmed not to be directed toward the popliteal artery, an all-inside suture device is introduced from the anterolateral portal. While the meniscus is penetrated, the surgeon can confirm by ultrasound images that the needle is directed away from the popliteal artery. The guide suture is pulled anteriorly to secure the anchors tightly, and an ultrasound confirms that the anchors are positioned behind the posterior portion of the LM. All sutures are secured under the assistance of ultrasound images, followed by arthroscopic confirmation of a properly secured LM by the all-inside repair technique.

The Danger Zone for Iatrogenic Neurovascular Injury in All-Inside Lateral Meniscal Repair in Relation to the Popliteal Tendon: An MRI Study

Background:

Lateral meniscal repair can endanger the nearby neurovascular structure (peroneal nerve or popliteal artery). To our knowledge, there have been no studies to evaluate the danger zone of all-inside meniscal repair through the anteromedial (AM) and anterolateral (AL) portals in relation to the medial and lateral edges of the popliteal tendon (PT).

Purpose:

To establish the risk of neurovascular injury and the danger zone in repairing the lateral meniscus in relation to the medial and lateral edges of the PT.

Study Design:

Descriptive laboratory study.

Methods:

Using axial magnetic resonance imaging (MRI) studies at the level of the lateral meniscus, lines were drawn to simulate a straight, all-inside meniscal repair device, drawn from the AM and AL portals to both the medial and lateral edges of the PT. In cases in which the line passed through the neurovascular structure, a risk of iatrogenic neurovascular injury was deemed, and measurements were made to determine the danger zones of neurovascular injury in relation to the medial or lateral edges of the PT.

Results:

Axial MRI images of 240 adult patients were reviewed retrospectively. Repairing the body of the lateral meniscus through the AM portal had a greater risk of neurovascular injury than repairs made through the AL portal in relation to the medial edge of the PT (P = .006). The danger zone in repairing the lateral meniscus through the AM portal extended 1.82 ± 1.68 mm laterally from the lateral edge of the PT and 3.13 ± 2.45 mm medially from the medial edge of the PT. Through the AL portal, the danger zone extended 2.81 ± 1.94 mm laterally from the lateral edge of the PT and 1.39 ± 1.53 mm medially from the medial edge of the PT.

Conclusion:

Repairing the lateral meniscus through either the AM or the AL portals in relation to the PT can endanger the peroneal nerve or popliteal artery.

Clinical Relevance:

The surgeon can minimize the risk of iatrogenic neurovascular injury in lateral meniscal repair by avoiding using the all-inside meniscal device in the danger zone area as described in this study.

Proximity of the neurovascular structures during all-inside lateral meniscal repair in children: a cadaveric study

Purpose

Meniscal repair has become increasingly common in a pediatric and adolescent population. All-inside repair techniques are utilized more often given their ease of insertion and decreased operative time required. However, there are possible risks including damage to adjacent neurovascular structures. The purpose of this study to was examine the proximity of the neurovascular structures during lateral meniscus repairs in pediatric specimens simulating a worst-case scenario.

Methods

Ten pediatric cadaveric knees (age 4–11) were utilized and simulated lateral meniscal repair through the posterior horn of the lateral meniscus and both medial and lateral to the popliteal hiatus through the body of the lateral meniscus was performed with an all-inside meniscal repair device. The distance to the popliteal artery or peroneal nerve was measured.

Results

During posterior horn repair, the average distance from the all-inside device to the popliteal artery was 1.9 mm ± 1.1 mm. There was penetration of the artery in one specimen. During repair on the medial side of popliteal hiatus, the average distance from the all-inside device to the peroneal nerve was 3.2 mm ± 2.0 mm. During repair on the lateral side of popliteal hiatus, the average distance from the all-inside device to the peroneal nerve was 12.4 mm ± 3.7 mm.

Conclusions

This study demonstrates that the proximity of the neurovascular structures to the lateral meniscus in children is extremely close and at high risk during meniscal repair with all-inside devices. This study gives important data for the proximity of these structures during these repair techniques.

Level of evidence

Level 5 Cadaveric Study.