Avoiding Injury to the Popliteal Neurovascular Bundle in All-Inside Suturing of the Posterior Horn of the Lateral Meniscus: A Magnetic Resonance Imaging Assessment of Portal Selection and Safety

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.

The Risk of Iatrogenic Posterior Neurovascular Injuries in Lateral Meniscal Repair Based on the Standard Arthroscopic Knee Position: A Magnetic Resonance Imaging Study

Background

Repair of the posterior horn of the lateral meniscus using an all-inside meniscal repair device involves the risk of iatrogenic posterior neurovascular injuries. Previous studies that have evaluated this risk were based on preoperative magnetic resonance imaging (MRI) with the knee in 30° of flexion and used landmarks that are impractical in the actual operative situation.

Purpose

To use an MRI model simulating actual knee arthroscopic conditions to (1) compare the potential risk of injuries related to the lateral border of the posterior lateral meniscus root (LMR) through the anterolateral versus anteromedial portal and (2) establish "safe" and "danger" zones to reduce the possibility of injuries to posterior neurovascular structures when performing lateral meniscal repair in relation to the lateral border of the posterior LMR.

Study Design

Descriptive laboratory study.

Methods

Using 29 axial MRI scans of knees in the figure-of-4 position with joint fluid dilatation at the level of the lateral meniscus, direct lines were drawn to simulate a straight all-inside meniscal repair device deployed from the anterolateral and anteromedial portals to the lateral border of the posterior LMR, extending 14 mm beyond the joint capsule. If the line passed through or touched a posterior neurovascular structure, a risk of iatrogenic injuries was noted, and measurements were made to determine the safe zone in relation to the lateral border of the posterior LMR.

Results

Repairing the lateral meniscus through the anterolateral portal in relation to the lateral border of the posterior LMR resulted in a significantly greater risk of posterior neurovascular injuries compared with repairing through the anteromedial portal, with injury incidences of 68.97% and 10.35%, respectively (P = .001). The safe zones of lateral meniscal repair through the anterolateral and anteromedial portals were 4.15 ± 1.87 and 6.57 ± 0.98 mm, respectively, beyond the lateral border of the posterior LMR.

Conclusion

The risk of posterior neurovascular injuries when repairing posterior lateral meniscal tissue was found to be significantly greater through the anterolateral portal compared with the anteromedial portal.

Clinical Relevance

Surgeons can use the safe zones as defined in this study to decrease the risk of iatrogenic posterior neurovascular injuries during arthroscopic lateral meniscal repair.

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.

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.

An Arthroscopic Pull-Out Suture Technique to Repair Incomplete Radial Tears of the Lateral Meniscus Posterior Horn Adjacent to the Root Attachment Combined With Anterior Cruciate Ligament Reconstruction

Radial tears of the lateral meniscus posterior horn are one of the most common lateral meniscal injuries accompanied by acute anterior cruciate ligament disruption. Meniscus-preserving therapy is recommended in the case of a radial lateral meniscal tear to preserve its dynamic behavior. We introduce an arthroscopic pull-out technique for repairing incomplete radial tears of the lateral meniscus posterior horn combined with anterior cruciate ligament reconstruction. In this technique, a ring hoop is made through which the tear ends of lateral meniscus on both sides are tightened by adjusting tension of stitches, providing annular and downward tension for lateral meniscus, both of which are critical to the stability of the lateral meniscus. The resident part of lateral meniscus adjacent to the posterior root is not subject to much tension in this technique because of the pull-out fixation of lateral meniscus posterior horn, thus providing support for healing and restoring the hoop action of the lateral meniscus.

The Risk of Iatrogenic Peroneal Nerve Injury in Lateral Meniscal Repair and Safe Zone to Minimize the Risk Based on Actual Arthroscopic Position: An MRI Study

BACKGROUND

Lateral meniscal repair using an all-inside meniscal repair device involves a risk of iatrogenic peroneal nerve injury. To our knowledge, there have been no previous studies evaluating the risk of injury with the knee in the standard operational figure-of-4 position with joint dilatation in arthroscopic lateral meniscal repair.

PURPOSE

To evaluate and compare the risk of peroneal nerve injury and establish the safe and danger zones in repairing the lateral meniscus through the anteromedial, anterolateral, or transpatellar portal in relation to the medial and lateral borders of the popliteal tendon (PT).

STUDY DESIGN

Descriptive laboratory study.

METHODS

Using axial magnetic resonance imaging (MRI) studies of knees in the figure-of-4 position with joint fluid dilatation at the level of the lateral meniscus, we drew direct lines to simulate a straight all-inside meniscal repair device deployed from the anteromedial, anterolateral, and transpatellar portals to the medial and lateral borders of the PT. If the line passed through or touched the peroneal nerve, a risk of iatrogenic peroneal nerve injury was noted, and measurements were made to determine the safe and danger zones for peroneal nerve injury in relation to the medial or lateral border of the PT.

RESULTS

Axial MRI images of 29 adult patients were reviewed. Repairing the lateral meniscus through the anteromedial portal in relation to the lateral border of the PT and through the anterolateral portal in relation to the medial border of the PT had a 0% risk of peroneal nerve injury. The "safe zone" in relation to the medial border of the PT through the anterolateral portal was between the medial border of the PT and 9.62 ± 4.60 mm medially from the same border.

CONCLUSION

It is safe to repair the body of the lateral meniscus through the anteromedial portal in the area lateral to the lateral border of the PT or through the anterolateral portal in the area medial to the medial border of the PT.

CLINICAL RELEVANCE

There is a risk of iatrogenic peroneal nerve injury during lateral meniscal repair. Thus, we recommend repairing the lateral meniscal tissue through the anteromedial portal in the area lateral to the lateral border of the PT and using the anterolateral portal in the area medial to the medial border of the PT, as neither of these approaches resulted in peroneal nerve injury. Additionally, the surgeon can decrease this risk by repairing the meniscal tissue using the all-inside meniscal device in the safe zone area.

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.

Vascular Complications in Sports Surgery: Diagnosis and Management

Orthopedic sports surgery of the knee and shoulder is generally considered to be safe and effective. Vascular complications can occur during or after arthroscopy of either joint. A thorough understanding of anatomy, particularly when placing portals in non-routine locations, is extremely important. Prompt recognition of any vascular complication is of significant importance. This review will discuss the potential vascular complications for both knee and shoulder sports surgery, review the relevant anatomy, and discuss the treatment and expected outcome of each.

Assessment of popliteal neurovascular safety during all-inside suturing of the posterior horn of the lateral meniscus using Upright MRIs of the knee joint

BACKGROUND

To examine the risk of injury to the popliteal neurovascular bundle (pNVB) during all-inside repair of the posterior horn of the lateral meniscus (PHLM) using Upright-MRIs.

METHODS

Upright-MRIs of 61 knees in extension (ext) and 90°-flexion (flex) were included. Distance D from the PHLM to the pNVB was compared between extended and 90°-flexed position, subgroups with/without joint-effusion and evaluated according to demographics. Portal safety was assessed simulating suturing of the PHLM via four arthroscopy portals. Distance d (shortest space from the simulated suturing-device trajectory lines to the pNVB) was compared among portals in increasing distances from the posterior cruciate ligament (PCL).

RESULTS

D is longer in flex (17.3 ± 6.0 mm) than in ext (11.3 ± 4.2 mm, p < 0.0001). MRIs with joint-effusion displayed longer values of D than scans without joint-effusion (flex: 20.4 ± 7.1 mm vs. 16.1 ± 5.2 mm, p = 0.012). Shorter distances are associated with female gender, lower body weight and lower BMI. At 0 mm from the PCL, the 1 cm-lateral portal was the safest (p < 0.0001) whereas at 3 mm/6mm/9mm/12 mm the 1 cm-medial portal showed the longest d values (p < 0.0001 each).

CONCLUSION

All-inside suturing of the PHLM is safer in 90°-flexion, in presence of intraarticular fluid and in male patients with increasing weight/BMI. Sutures of the PHLM at 0 mm from the PCL are safer from a 1 cm-lateral portal whereas for tears located ≥ 3 mm from the PCL a 1 cm-medial portal involves a lower neurovascular risk. Upright-MRI proves excellent for preoperative planning to minimize neurovascular risks.

Editorial Commentary: Caveat Medicus-Beware of Meniscal Repair

Perform meniscal repair with care and beware! Because of the well-known adverse consequences of meniscectomy, especially in the lateral compartment, meniscal repair should be considered for every meniscal tear even if it requires pushing the envelope. Nevertheless, the surgeon must be keenly aware of neuromuscular risks associated with this technique. For the posterior horn of the lateral meniscus, extreme caution must be exercised, particularly in younger and presumably smaller female patients. When a surgeon is performing all-inside repair of the posterior horn of the lateral meniscus, a medial portal 1 cm medial to the patellar tendon is recommended for placement of sutures. In addition, he or she should limit the depth of penetration of all-inside needles and exercise extreme vigilance during and after surgery (checking for potential neurovascular injury in the recovery room).