Lateral Meniscal Oblique Radial Tears Are Common With ACL Injury: A Classification System Based on Arthroscopic Tear Patterns in 600 Consecutive Patients

Lateral femoral tunnel preparation and graft fixation for anterior cruciate ligament reconstruction–A discussion

This article provides a discussion and commentary around the recent advances in arthroscopic anterior cruciate ligament reconstruction (ACLR), with a focus on the aspects of lateral femoral tunnel preparation and graft fixation techniques. The paper explores and comments on a recently published review by Dai et al, titled "Research progress on preparation of lateral femoral tunnel and graft fixation in ACLR", while providing insight into its relevance within the field of ACLR, and recommendations for future research.

Meniscus Tears in Elite Athletes: Treatment Considerations, Clinical Outcomes, and Return to Play

PURPOSE OF REVIEW

Management of meniscal injuries in the elite athlete is a difficult problem secondary to the high demands of athletic competition, the need for a timely return to sport, and the desire to maximize performance over time. The purpose of this review is to provide an up-to-date summary on the current literature and trends regarding the management of meniscus injuries with a special consideration for elite athletes.

RECENT FINDINGS

Historically, partial meniscectomy has been the primary treatment option for meniscus injuries. However, in recent years there has been an increased emphasis on meniscus preservation due to the increased risk of cartilage degeneration over time. Moreover, while partial meniscectomy still provides a quicker return to sport (RTS), recent literature has demonstrated similar rates of RTS and return to pre-injury levels between partial meniscectomy and meniscus repair. In the setting of symptomatic meniscal deficiency, meniscus allograft transplantation has become an increasingly utilized salvage procedure with promising yet variable outcomes on the ability to withstand elite competition. Currently, there is no uniform approach to treating meniscal injuries in elite athletes. Therefore, an individualized approach is required with consideration of the meniscus tear type, location, concomitant injuries, athlete expectations, rehabilitation timeline, and desire to prevent or delay knee osteoarthritis. In athletes with anatomically repairable tears, meniscus repair should be performed given the ability to restore native anatomy, provide high rates of RTS, and mitigate long-term chondral damage. However, partial meniscectomy can be indicated for unrepairable tears.

Management of Meniscus Pathology with Concomitant Anterior Cruciate Ligament Injury

PURPOSE OF REVIEW

The purpose of this review is to summarize current clinical knowledge on the prevalence and types of meniscus pathology seen with concomitant anterior cruciate ligament (ACL) injury, as well as surgical techniques, clinical outcomes, and rehabilitation following operative management of these pathologies.

RECENT FINDINGS

Meniscus pathology with concomitant ACL injury is relatively common, with reports of meniscus pathology identified in 21-64% of operative ACL injuries. These concomitant injuries have been associated with increased age and body mass index. Lateral meniscus pathology is more common in acute ACL injury, while medial meniscus pathology is more typical in chronic ACL deficiency. Meniscus tear patterns associated with concomitant ACL injury include meniscus root tears, lateral meniscus oblique radial tears of the posterior horn (14%), and ramp lesions of the medial meniscus (8-24%). These meniscal pathologies with concomitant ACL injury are associated with increased rotational laxity and meniscal extrusion. There is a paucity of comparative studies to determine the optimal meniscus repair technique, as well as rehabilitation protocol, depending on specific tear pattern, location, and ACL reconstruction technique. There has been a substantial increase in recent publications demonstrating the importance of meniscus repair at the time of ACL repair or reconstruction to restore knee biomechanics and reduce the risk of progressive osteoarthritic degeneration. Through these studies, there has been a growing understanding of the meniscus tear patterns commonly identified or nearly missed during ACL reconstruction. Surgical management of meniscal pathology with concomitant ACL injury implements the same principles as utilized in the setting of isolated meniscus repair alone: anatomic reduction, biologic preparation and augmentation, and circumferential compression. Advances in repair techniques have demonstrated promising clinical outcomes, and the ability to restore and preserve the meniscus in pathologies previously deemed irreparable. Further research to determine the optimal surgical technique for specific tear patterns, as well as rehabilitation protocols for meniscus pathology with concomitant ACL injury, is warranted.

Three Morphological Risk Factors for Predicting Isolated Meniscal Bucket-handle Tear

Purpose

The study aimed to investigate whether morphometric variables of the knee can predict isolated meniscal bucket-handle tears and identify the risk factors.

Methods

The study included 146 participants with a mean age of 36.547 ± 12.279 years. They included two groups of 73 patients each: one group with isolated meniscal bucket-handle tears and another with no knee injury (control group). Magnetic resonance imaging findings of the participants were retrospectively assessed. A few morphometric variables associated with distal femur, proximal tibia, and cruciate ligaments were measured.

Results

Cruciate ligament tensity (CLT), medial femoral condylar height (MFCH), and lateral meniscal bone angle (LMBA) were found to be 12.7 ± 0.3, 30.1 ± 2.5 mm, and 21.2° ± 3.4°, respectively, in patients with meniscal bucket-handle tear, compared with 11.9 ± 0.2, 28.3 ± 2.7 mm, and 26.5° ± 3.7° in the control group, respectively. Based on multivariate Firth's logistic regression analysis, CLT (Odds ratio [OR]: 456.533; 95% confidence interval [CI]: 27.582 to > 999.999), MFCH (OR: 1.603; 95% CI: 1.023-2.513), and LMBA (OR: 0.780; 95% CI: 0.624-0.975) could distinguish between meniscal bucket-handle tears and knees without meniscus tears (p < 0.05). Based on the multicategorical multinominal regression model, CLT (OR: > 999.999; 95% CI: 49.937 to > 999.999) and MFCH (OR: 1.903; 95% CI: 1.005-3.606) were the determinant variables in differentiating medial meniscal bucket-handle tears from knees without meniscus tears (p < 0.05).

Conclusion

Large CLT, high medial condyle, and small LMBA were revealed as the morphometric risk factors for meniscal bucket-handle tear.

Association of Increased Lateral Femoral Condylar Ratio With Lateral Meniscus Posterior Root Tear in Noncontact ACL Injury

Background

In the setting of anterior cruciate ligament (ACL) injury, lateral meniscus posterior root tears (LMPRTs) are less readily diagnosed on preoperative magnetic resonance imaging (MRI). Therefore, to predict LMPRTs in ACL injuries, it is necessary to understand the risk factors associated with them.

Purpose/Hypothesis

The purpose of this study was to investigate the association of lateral femoral condylar ratio (LFCR) with LMPRTs in ACL injuries. It was hypothesized that an increased LFCR would be associated with LMPRTs in noncontact ACL injuries.

Study Design

Cohort study; Level of evidence, 3.

Methods

Enrolled were consecutive patients who underwent primary acute (<6 weeks from injury) ACL reconstruction after noncontact injury and had LMPRT confirmed on preoperative MRI and arthroscopically (combined group; n = 62) as well as patients who underwent isolated acute ACL reconstruction (isolated group; n = 80) who were matched to the combined group by age, height, and body mass index (BMI). All patients underwent surgery between January 1999 and November 2021. LFCR and posterior tibial slope (PTS) were measured and compared between the isolated and combined groups. The area under the receiver operating characteristic curve (AUC) was calculated to determine the cutoff for detecting increased risk of LMPRTs.

Results

The demographic characteristics of the 2 groups did not differ significantly, nor did the PTS. The LFCR was a significant factor (odds ratio [OR], 1.23; P = .001) associated with LMPRT. Patient age, height, BMI, and PTS were not associated with LMPRT. The AUC (0.66; 95% CI, 0.57-0.75) for LFCR had a sensitivity of 39% and specificity of 90% to predict LMPRT. The calculated cutoff associated with an increased risk for LMPRT when compared with the isolated group was 67.0% (OR, 4.98; 95% CI, 2.10-11.79).

Conclusion

Increased LFCR was associated with the presence of LMPRTs in patients with acute ACL injuries. The LFCR may provide surgeons with additional information regarding the risk of having a concomitant LMPRT when planning ACL reconstructions.

Increased Posterior Tibial Slope Is Associated With Increased Risk of Meniscal Root Tears: A Systematic Review

BACKGROUND

While increased posterior tibial slope (PTS) is an established risk factor for anterior cruciate ligament tears, the association between tibial slope and meniscal posterior root tears is not well-defined.

PURPOSE

To summarize the available literature evaluating the association between PTS and meniscus root injuries compared with patients without root tears.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A literature search was performed using the Scopus, PubMed, and Embase databases. Human clinical studies evaluating the associations between the medial tibial slope (MTS), lateral tibial slope (LTS), lateral-to-medial (L-to-M) slope asymmetry, and the risk of meniscus root tears were included. Patients with medial meniscus posterior root tears (MMPRTs) and lateral meniscus posterior root tears (LMPRTs) were compared with a control group without root injury. Study quality was assessed using the methodological index for non-randomized studies criteria.

RESULTS

Ten studies with 1313 patients were included (884 patients with root tears; 429 controls). The LMPRT subgroup (n = 284) had a significantly greater LTS (mean ± SD, 7.3°± 1.5° vs 5.7°± 3.91°; P < .001), MTS (5.26°± 1.2° vs 4.8°± 1.25°; P < .001), and increased L-to-M asymmetry (2.3°± 1.3° vs 0.65°± 0.5°; P < .001) compared with controls. The MMPRT group (n = 600) had significantly increased MTS relative to controls (8.1°± 2.5° vs 4.3°± 0.7°; P < .001). Furthermore, there was a higher incidence of noncontact injuries (79.3%) and concomitant ramp lesions (56%) reported in patients with LMPRT.

CONCLUSION

Increased MTS, LTS, and L-to-M slope asymmetry are associated with an increased risk of LMPRTs, while increased MTS is associated with MMPRTs. Surgeons should consider how proximal tibial anatomy increases the risk of meniscus root injury.

Transtibial Lateral Meniscal Root Repair Technique to Appose Remnant Root With Torn Body: The Double Compression Knot

Anterior cruciate ligament reconstructions are often performed with associated procedures, most commonly for associated meniscal tears. The lateral meniscal root tear is a commonly associated injury, which increases rotational instability and results in altered tibiofemoral biomechanics. Lateral meniscectomy results in poorer functional and long-term outcomes, making repair vital. The position of the lateral root tear makes its repair technique complicated. Because of the proximity to vessels posteriorly, the all-inside technique is considered potentially unsafe, and current transtibial repair techniques fail to appose the body with the root remnant. In the lineage of Laprade, who proclaimed the use of a transtibial suture for radial tears elsewhere in the knee in order to reduce the shear force, we describe a transtibial technique that optimizes meniscal apposition, theoretically improving the repair biomechanics and is technically easier to perform in comparison to suture hook techniques with one tunnel and one suture.

Efficacy of all-inside devices in reducing gap and step-off in knee extension for ramp lesion repair: A cadaveric study

PURPOSE

The aim of this study is to assess the dynamics of the tear site of meniscal ramp lesions, particularly considering knee flexion angles, and validate anchor fixation using an all-inside device.

METHODS

Eight Thiel-embalmed paired cadaveric knees with their whole bodies were used in this study. The ramp lesions were created arthroscopically, and ramp lesion dynamics were evaluated by gradually extending the knee from 90° of knee flexion. Changes in the gap and step-off (0: no step-off; 1: cross-sectional overlap exists; and 2: tibial articular surface exposed) were evaluated at 90°, 60°, 30°, and 10° of knee flexion. After dynamic evaluation, all-inside repairs of the ramp lesions using all-inside devices were conducted. Dissection was performed to confirm the position of anchor fixation.

RESULTS

As the knee was extended, the gap significantly decreased at all knee flexion angles. Similarly, the step-off grade decreased as the knee was extended, and the step-off completely disappeared in all cases when the knee was extended from 30° to 10°. The average knee flexion angle at which the gap and step-off completely disappeared was 22.5°. After suturing the ramp lesion, arthroscopic evaluation showed that the gap had disappeared and the step-off had been repaired in all cases. Anchor fixation locations were not found within the joint but were fixed to the semimembranosus tendon or its surrounding articular capsule. Overall, 31% (5/16) anchors were fixed to the attachment site of the semimembranosus tendon, whereas the remaining were fixed to the articular capsule, located peripherally to the semimembranosus tendon.

CONCLUSION

Suturing with an all-inside device for ramp lesions is a good option, and the repair in knee extension was found to be reasonable, considering the dynamics of ramp lesions in this study.

LEVEL OF EVIDENCE

Level IV.

Alteration in ACL loading after total and partial medial meniscectomy

Anterior cruciate ligament (ACL) injuries are often caused by high impact loadings during competitive sports but may also happen during regular daily activities due to tissue degeneration or altered mechanics after a previous knee injury or surgery such as meniscectomy. Most existing research on ACL injury has focused on impact loading scenarios or the consequence of ACL injury on meniscus. The objective of the present study was to investigate the effects of varying degrees of medial meniscectomy on the mechanics of intact ACL by performing a poromechanical finite element analysis under moderate creep loadings. Four clinical scenarios with 25%, 50%, 75% and total medial meniscectomy were compared with the intact knee finite element model. Our results suggested that different medial meniscal resections may increase, at different extents, the knee laxity and peak tensile stress in the ACL, potentially leading to collagen fiber fatigue tearing and altered mechanobiology under normal joint loadings. Interestingly, the ACL stress actually increased during early knee creep (~ 3 min) before it reached an equilibrium. In addition, meniscectomy accelerated ACL stress reduction during knee creep, transferred more loading to tibial cartilage, increased contact pressure, and shifted the contact center posteriorly. This study may contribute to a better understanding of the interaction of meniscectomy and ACL integrity during daily loadings.

A non-weight bearing protocol after ACL reconstruction improves static anterior tibial translation in patients with elevated slope and increased weight bearing tibial anterior translation

PURPOSE

Aim of this study is to evaluate the impact of a non-weight bearing (NWB) protocol within 21 post-operative days after anterior cruciate ligament (ACL) reconstruction on static and dynamic anterior tibial translations (SATT and DATT, respectively). The hypothesis is that delayed WB would improve ATT at 9 months follow-up.

METHODS

A series of patients treated with ACL reconstruction was retrospectively reviewed, comparing a group with immediate post-operative weight bearing (WB group) and a group without post-operative weight bearing (NWB group). The NWB protocol was applied to patients with posterior tibial slope (PTS) ≥ 12°, pre-operative SATT ≥ 5 mm, and/or meniscal lesions of root or radial type. SATT, and PTS were measured on 20° flexion monopodal lateral x-rays, while DATT on Telos™ x-rays at pre-operative and 9-months follow-up.

RESULTS

One hundred seventy-nine patients were included (50 NWB group, 129 WB group). The SATT worsened in the WB group with a mean increase of 0.7 mm (SD 3.1 mm), while in the NWB group, the SATT improved with a mean decrease of 1.4 mm (SD 3.1 mm) from the pre-operative to 9 months' follow-up (p < 0.001). The side-to-side Telos™ evaluation showed a significant improvement in DATT within both the groups (p < 0.001), but there was no difference between the two groups (p = 0.99).

CONCLUSION

The post-operative protocol of 21 days without WB led to an improvement in SATT at 9 months without an influence on DATT, and it is recommended for patients with a SATT ≥ 5 mm and/or a PTS ≥ 12° as part of an "à la carte" approach to ACL reconstruction.

LEVEL OF EVIDENCE

Level IV, Retrospective case series.

Outcomes of Lateral Meniscal Oblique Radial Tear Repair Compared With Intact Meniscus After ACL Reconstruction: A Cohort Study

Background

Recently, the posterior horn lateral meniscal oblique radial tear (LMORT) was identified in 12% of acute anterior cruciate ligament (ACL) injuries. However, patient-reported outcomes for repair of this relatively common tear have not been reported.

Purpose

To determine the minimum 2-year functional outcomes after LMORT repair at the time of ACL reconstruction (ACLR) compared to a matched cohort of patients who underwent isolated ACLR (iACLR).

Study Design

Cohort study; Level of evidence, 3.

Methods

Included were 100 patients (mean age at surgery, 21 years; range, 13-45 years) who underwent primary ACLR between 2010 and 2018. The mean follow-up period was 4.1 ± 2.0 years (range, 2.0-9.2 years). A total of 50 patients with surgically repaired LMORT type 3 or type 4 lesions, defined as partial or complete tears >10 mm from the root (LMORT group) were matched 1:1 based on age, date of surgery, and graft choice with 50 patients who underwent iACLR (iACLR group). The postoperative outcomes were compared between groups using the International Knee Documentation Committee subjective score (sIKDC) and the Tegner activity scale. An updated medical history was obtained via the electronic medical record to determine any subsequent complications and reoperations.

Results

There was 1 ACL graft failure in each group as well as 5 (10%) reoperations per group. None of the patients in the LMORT group necessitated a lateral meniscal revision repair or partial meniscectomy. The LMORT and iACLR groups reported comparable sIKDC scores (92.5 ± 6.8 vs 91.9 ± 8.2, respectively; P = .712) as well as Tegner scores (6.7 ± 1.8 vs 6.6 ± 1.8, respectively; P = .910) at final follow-up. No failures of the LMORT repairs were reported.

Conclusion

The study findings demonstrated that reoperations, graft failure rates, patient-reported outcomes, and patient activity levels at ≥2 years after type 3 and 4 LMORT repairs at the time of ACLR compared favorably with those of a matched cohort of patients who underwent iACLR with intact meniscus.

Evaluation of the All-Inside Technique for the Repair of Lateral Meniscus Root Tears at 1 Year After ACL Reconstruction

Background

The presence of a lateral meniscus root tear (LMRT) in patients with an anterior cruciate ligament (ACL) tear makes the knee more unstable and increases the risk of osteoarthritis and osteonecrosis. An all-inside suture repair technique without bone tunnels has been proposed to treat LMRT.

Purpose

To compare the 1-year postoperative findings between patients who underwent ACL reconstruction combined with LMRT repair (LMRT group) and patients who underwent isolated ACL reconstruction (control group).

Study Design

Cohort study; Level of evidence, 3.

Methods

The LMRT group consisted of 19 patients, and the control group consisted of 56 patients. In this study, the authors compared the postoperative magnetic resonance imaging (MRI) findings (meniscal extrusion, ghost sign, and hyperintensity in the tibial plateau beneath the LMRT), functional outcomes (International Knee Documentation Committee [IKDC], Lysholm, and Tegner scores), and reoperation rate between groups. The primary endpoint was analyzed by comparing, in the LMRT group, the 1-sided 97.5% confidence interval (CI) of the mean lateral meniscal extrusion at 1 year to the limit of noninferiority (fixed at 0.51). To take into account imbalanced baseline characteristics between groups, adjusted mean meniscal extrusion (with 1-sided 97.5% CI) was assessed using a linear regression model.

Results

The mean follow-up was 12.2 months (range, 7.7-14.7 months) in the control group and 11.5 months (range, 7.1-13.0 months) in the LMRT group (P = .06). For meniscal extrusion, the LMRT group was noninferior to the control group. The mean meniscal extrusion was 2.19 mm (97.5% CI, -infinity to 2.68 mm) in the LMRT group and 2.03 mm (97.5% CI,-infinity to 2.27 mm) in the control group, indicating that the upper boundary of the 1-sided 97.5% CI in the LMRT group was less than the noninferiority threshold of 2.78 (ie, 2.27 mm + 0.51 mm = 2.78 mm). There was a statistically significant difference in the IKDC score between the LMRT and control groups (77.2 ± 8.1 vs 80.3 ± 7.3, respectively; P = .04). There was no between-group difference in the other MRI parameters, the Lysholm and Tegner scores, or the reoperation rate.

Conclusion

There was no significant difference in extrusion on MRI or clinical outcomes at 1-year follow-up in patients who underwent ACL reconstruction with all-inside LMRT repair compared with patients who did not have an LMRT.

Coronal extrusion of the lateral meniscus does not increase after pullout repair of the posterior root of the lateral meniscus at short-term follow-up

PURPOSE

Posterior lateral meniscus root (PLMR) tears are injuries that commonly occur together with anterior cruciate ligament (ACL) tears. The aim of this study was to evaluate the clinical and radiological outcome of PLMR repair accompanying ACL reconstruction. Specifically, PLMR healing rates, meniscal extrusion behavior and their influence on patient-reported outcome measures (PROMs) were analyzed. It was hypothesized that PLMR repair shows satisfactory healing rates and coronal meniscal extrusion does not increase significantly following PLMR repair.

METHODS

Patients that underwent PLMR repair between 2014 and 2019 were evaluated at least 12 months postoperatively. At follow-up, magnetic resonance imaging (MRI) was performed in order to evaluate the PLMR healing behavior (complete vs. partial vs. no healing) as well as the coronal and sagittal meniscal extrusion in comparison with the preoperative MRI. Additionally, patient-reported outcome measures (PROMs; Lysholm score, International Knee Documentation Committee subjective knee form [IKDC]) were compiled. Pre- and postoperative meniscal extrusion were tested for statistical significance using the paired t test. The Kruskal-Wallis test was used to compare extrusion values and PROMs in relation to different healing states. A correlation analysis was conducted using the Pearson correlation coefficient between differences in meniscal extrusion and PROMs.

RESULTS

Out of 25 patients, 18 patients (72.0%; 11 male and seven female) were available for final assessment at a mean follow-up of 40.8 ± SD 17.5 months. One revision PLMR repair was performed five months after the initial repair. In 14 cases (77.8%), healing of the lateral meniscus was observed (6 × complete, 8 × partial). Coronal extrusion of the lateral meniscus did not increase significantly following PLMR repair (2.0 ± 1.5 mm vs. 2.1 ± 1.3 mm; p = 0.645). Sagittal extrusion increased significantly (25.7 ± 2.4 mm vs. 27.0 ± 1.4 mm; p < 0.001). The healing status of the PLMR showed no significant association with meniscal extrusion or PROMs (p > 0.05). But a higher increase in coronal meniscal extrusion negatively affected PROMs (Lysholm score: p = 0.046, r = - 0.475; IKDC: p = 0.003, r = - 0.651).

CONCLUSION

High healing rates of the PLMR and no significant increase in coronal extrusion may be expected following combined PLMR repair and ACL reconstruction. But a greater increase in postoperative coronal meniscal extrusion correlates with less favorable clinical results. A greater increase in sagittal extrusion was observed, but this did not influence the clinical outcome.

LEVEL OF EVIDENCE

Retrospective Case Series; IV.

Low reoperation rate following lateral meniscus root repair: clinical outcomes at 2 years follow-up

PURPOSE

The aim of this study was to review the outcomes of lateral meniscus posterior root tears repair at the time of ACL reconstruction at a minimum 2-year follow-up.

METHODS

Between March 2015 and August 2018, 2017 patients underwent primary ACL reconstruction and were considered for study eligibility. Lateral meniscus posterior root tears were identified arthroscopically, and repair was performed with a transtibial pull-out suture technique or a side-to-side suture technique. Clinical outcomes were recorded at the time of physical examination. At the end of the study period, patients were contacted to determine whether they had required reoperation.

RESULTS

Lateral meniscus posterior root tears were identified in 153 out of the 2,017 primary ACL reconstructions (7.6%). Ninety-nine patients were included for analysis: 23 transtibial pull-out sutures and 76 side-to-side repairs. At a mean follow-up of 42 ± 10 months, one patient (1%) had undergone reoperation for failure of the side-to-side repair. There were 11 reoperations in 10 patients (10.1%), including 6 cyclops syndrome, 1 graft rupture, 1 tibial bone cyst, 1 medial and 1 lateral meniscus repair failure, and 1 arthrolysis. Postoperatively, ninety (90.9%) patients were graded A for the IKDC objective score and 9 (9.1%) patients were graded B, with an IKDC subjective score of 86.9 ± 7.6, a Lysholm score of 90.7 ± 6.7 and a median Tegner Activity Scale of 6 (3-9). All of their objective and subjective evaluations improved after surgery (p < 0.001) except for the Tegner Activity Scale. Ten patients underwent second look arthroscopy (10.1%), lateral meniscus healing was observed in 9 out of 10 patients (90%).

CONCLUSION

This study demonstrated that lateral meniscus posterior root tear repair is a safe procedure with a very low reoperation rate at a minimum follow-up of 2 years.

LEVEL OF EVIDENCE

IV.

Posterior Horn Lateral Meniscal Oblique Radial Tear in Acute Anterior Cruciate Ligament Reconstruction Incidence and Outcomes After All-Inside Repair: Clinical and Second-Look Arthroscopic Evaluation

BACKGROUND

The term posterior horn lateral meniscal oblique radial tear (LMORT) has emerged to characterize the tear patterns of the lateral meniscus in many patients with acute anterior cruciate ligament (ACL) injury. There is a lack of data regarding the exact incidence according to the types of LMORT and clinical outcomes.

PURPOSES

(1) To investigate the incidence of LMORT according to type in patients with acute ACL reconstruction (ACLR) and (2) to identify healing status after repair of LMORT via second-look arthroscopy and clinical outcomes.

STUDY DESIGN

Case series; Level of evidence: 4.

METHODS

Patients who underwent primary ACLR within 6 months of injury were retrospectively reviewed. The LMORT was classified into 4 types based on the severity and distance from the root: type 1 (partial tear <10 mm from the root), type 2 (complete tear <10 mm from the root), type 3 (partial tear >10 mm from the root), type 4a (complete tear >10 mm from the root), and type 4b (type 4a with longitudinal tear at the meniscocapsular junction). Only patients with LMORT were isolated, and the clinical outcomes were compared according to the healing status of LMORT in second-look arthroscopy.

RESULTS

Of 635 patients with ACLR, LMORT was identified in 97 patients (15.3%), and type 4 LMORT accounted for the largest proportion (n = 62; 32.6%) of 190 lateral meniscal tears. In 79 patients with LMORT who satisfied the 2-year follow-up period, all patient-reported outcomes (PROs), including the Lysholm (preoperative, 64.1; postoperative, 88.2) and International Knee Documentation Committee subjective (preoperative, 50.5; postoperative, 82.9) scores, were significantly improved (P < .001) 31.8 months postoperatively. Of the 61 patients who underwent second-look arthroscopy, 49 (80.3%) were classified into the complete healing group. There was no significant difference in postoperative PROs between the complete and partial healing groups.

CONCLUSION

The incidence of LMORT was 15.3% in patients with acute ACL injury, and type 4 LMORT was the most common type. Complete healing of LMORT was achieved in 80.3% of patients who underwent second-look arthroscopy, and the PROs were significantly improved postoperatively. Good clinical results can be achieved if the LMORT is repaired as much as possible during ACLR.

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.

Nursing Education of Lateral Oblique Complications of Neurosurgery under Microscope

In order to solve the problem of nursing education of lateral oblique complications, a nursing education solution of lateral oblique complications of neurosurgery under the microscope was proposed. The method used subjective evaluation and objective evaluation to systematically evaluate the basic training module. In subjective evaluation, the authenticity score of surgical simulator was 3.65 ± 0.01, the realism score of surgical instruments was 3.81 ± 0.01, the realism score of tactile sense was 3.75 ± 0.01, the operating environment score was 3.60 ± 0.01, and the overall effect score was 3.63 ± 0.01. The difficulty score of the whole training was 3.15 ± 0.01. In the aspect of objective evaluation, the entropy method was used to process the data of training track, training angle, training time, trigger times, success times, failure times, and other indicators of 24 trainers collected, and the experiment verified the nursing education of lateral oblique complications of neurosurgery under the microscope.

Kinematic Analysis of Lateral Meniscal Oblique Radial Tears in Anterior Cruciate Ligament-Reconstructed Knees: Untreated Versus Repair Versus Partial Meniscectomy

BACKGROUND

Lateral meniscal oblique radial tears (LMORTs) affect joint and meniscal stability in anterior cruciate ligament (ACL)-deficient knees.

PURPOSE

To determine the clinically relevant kinematics associated with the most common posterior horn LMORT lesion types, types 3 (LMORT3) and 4 (LMORT4), untreated versus arthroscopic repair versus partial meniscectomy in combination with ACL reconstruction (ACLR).

STUDY

Controlled laboratory study.

METHODS

Sixteen cadaveric knees underwent robotic testing for anterior drawer and pivot-shift simulations at multiple knee flexion angles in ACL-intact and ACL-deficient states, followed by sequential testing of arthroscopic ACLR, LMORT3 lesion, LMORT3 repair, and partial meniscectomy (n = 8). The same testing sequence was performed for LMORT4 lesions (n = 8).

RESULTS

ACLR restored kinematics in ACL-deficient knees to intact levels for all metrics tested. For anterior drawer, ACLR + LMORT3 tear and partial meniscectomy resulted in significantly greater anterior translation compared with ACL-intact at all angles (P < .05) and compared with ACLR at 60° and 90° (P < .014). For pivot shift, compared with ACL-intact knees, ACLR + LMORT3 tear resulted in significantly more anterior translation at 15° (P = .041); and for ACLR + partial meniscectomy, at both 0° and 15° (P < .03). ACLR + LMORT4 tear and partial meniscectomy resulted in significantly greater anterior translation for anterior drawer (P < .04) and pivot-shift testing (P < .05) compared with intact and ACLR knees at all angles tested. ACLR + LMORT3 repair and ACLR + LMORT4 repair restored kinematics to ACLR and intact levels at all angles tested. ACLR + LMORT3 tear (P < .008) and both LMORT4 tear and partial meniscectomy (P < .05) resulted in increased meniscal extrusion compared with intact and ACLR statuses at all tested angles for anterior drawer and pivot shift, while repairs restored meniscal stability to ACLR and intact levels.

CONCLUSION

Untreated LMORT tears increased anterior translation, pivot shift, and meniscal extrusion after ACLR, while partial meniscectomy further exacerbated these detrimental effects in this cadaveric model. In contrast, arthroscopic side-to-side repair of LMORT lesions effectively restored measured knee kinematics.

CLINICAL RELEVANCE

LMORT lesions are common with ACL tears and adversely affect joint stability and meniscal extrusion. This study highlights the importance of repair of LMORT 3 and 4 lesions at the time of ACLR.

Arthroscopic Repair of Posterior Root Tears of the Lateral Meniscus with All-Suture Anchor

Meniscus root tears are increasingly being recognized and treated because of improved awareness and diagnostics. These injuries commonly occur in combination with knee ligament injuries. Untreated posterior meniscus root teats have been demonstrated to increase contact pressure and decrease contact area, ultimately leading to unfavorable joint loading and development of early osteoarthritis. Posterior lateral meniscus root tears (PLMRTs) also have been reported to increase anterior tibial translation and pivot shift in anterior cruciate ligament-deficient knees. Therefore, it is crucial to repair meniscal root tears when possible to restore knee joint loading and kinematics. Several techniques for repair of the PLMRT have been described. In this Technical Note, we describe our preferred technique for repair of PLMRT using an all-suture anchor. This technique is reproducible, does not need a tunnel, mitigates bungee effect of transtibial technique, and the anchor can easily be inserted on the footprint without a need for a guide.

Evidence-based rationale for treatment of meniscal lesions in athletes

Meniscal injuries in elite athletes are a common cause of missed game time and even have the potential to be career shortening. In this patient group, care must be paid not only to the pathology, but also to a player's contract status, time in the season, specific demands of his/her sport and position on the field, and future consequences. Successful treatment requires the clinician to understand the player's goals and needs, communicate effectively between all stakeholders, and a have knowledge of the challenges posed by the different types of meniscal tear seen in this population. Paramount is the distinction between injuries to the medial and lateral meniscus. Deficiency of the lateral meniscus, as a result of a tear or a meniscectomy, leads to frequent early problems and inexorably to chondral degeneration thereby affecting an athlete's ability to perform. Therefore, it is strongly recommended to repair the majority of lateral meniscal tears. Medial meniscal tears pose a more challenging treatment dilemma, as the success of partial meniscectomy in achieving reproducible, early return to play must be balanced against the long-term degenerative consequences. Many meniscal tears are correctly treated non-operatively.Level of evidence V.

Kinematic Analysis of Lateral Meniscal Oblique Radial Tears in the Anterior Cruciate Ligament-Deficient Knee

BACKGROUND

Lateral meniscal oblique radial tears (LMORT) occur frequently in conjunction with anterior cruciate ligament (ACL) disruption and are anatomically distinct from meniscus root tears.

HYPOTHESIS/PURPOSE

The purpose of this study was to characterize the effects of LMORT types 3 (LMORT3) and 4 (LMORT4) lesions on joint stability and meniscal extrusion in ACL-deficient knees. Our hypothesis was that both lesions would promote significant increases in anterior translation and meniscal extrusion, with the LMORT4 lesion having a greater effect.

STUDY DESIGN

Controlled laboratory study.

METHODS

Two matched pairs of cadaveric knees (n = 4) were used to optimize the testing sequence. Additional cadaveric knees with LMORT3 (n = 8) and LMORT4 (n = 8) lesions created after ACL transection underwent robotic kinematic testing for anterior drawer and pivot-shift simulations with associated ultrasound-measured meniscal extrusion at clinically relevant knee flexion angles.

RESULTS

Optimization testing showed no differences on the effect of LMORT4 lesions for anterior translation and lateral meniscal extrusion with ACL-intact versus ACL-deficient knees. ACL deficiency and LMORT3 and LMORT4 lesions with ACL deficiency were associated with significantly greater anterior translation compared with ACL-intact state for both anterior drawer and pivot-shift testing at all flexion angles (P < .001). ACL deficiency with either LMORT3 or LMORT4 lesion was associated with significantly greater anterior translation than was ACL deficiency only (P < .005) for anterior drawer testing at 90° of flexion. Meniscal extrusion was greater with LMORT3 and LMORT4 lesions compared with ACL deficiency only (P < .05) for anterior drawer at 60° of flexion and for pivot shift at 15° of flexion. The LMORT4 lesion demonstrated increased anterior translation for anterior drawer (P = .003) at 60° of flexion (12%) as well as for pivot shift at 15° of flexion (7%) and 30° of flexion (13%) (P < .005) compared with ACL deficiency only.

CONCLUSION

In this cadaveric model, the addition of an LMORT3 or LMORT4 lesion increased anterior laxity for both the anterior drawer and the pivot shift when compared with an isolated ACL tear. Lateral meniscal extrusion was also exacerbated by these LMORT lesions.

CLINICAL RELEVANCE

LMORT lesions, distinct from meniscus root tears, occur frequently in conjunction with ACL tears. This study characterized the biomechanical consequences of LMORT3 and LMORT4 lesions on joint stability and meniscal function, highlighting the importance of diagnosing and treating LMORT lesions at the time of ACL reconstruction.

Good Surgical Outcomes After Concomitant Repair of Double Radial Tears of the Lateral Meniscus and Anterior Cruciate Ligament Reconstruction

Purpose

To describe double radial tears of the lateral meniscus (LM), report early clinical treatment outcomes, and determine reoperation and failure rates.

Methods

Twenty-one (N = 21) consecutive cases of arthroscopic-treated lateral meniscus double radial tears treated between 2012 and 2018 were reviewed, including 15 males (71.4%) and 6 females (28.6%). Meniscus repairs were all performed at the time of anterior cruciate ligament (ACL) reconstruction. Patients with associated fractures or prior surgeries were excluded. Concomitant injuries were reported, as were preinjury and postoperative Tegner scores, preoperative and postoperative visual analogue pain scale (VAS) scores, and postoperative International Knee Documentation Committee (IKDC) subjective scores. Reoperation and failure rates were documented.

Results

Twenty-one (N = 21) tears were located in the posterior horn of the meniscus near the root attachment; 15 (71.4%) underwent all-inside repair, 4 (19.0%) underwent transtibial pull-through repair, 1 (4.8%) was partially debrided, and 1 (4.8%) was left untreated. Twenty-one tears (N = 21) were in the body of the meniscus; 7 (33.3%) were repaired, 7 (33.3%) were partially debrided, and 7 (33.3%) were left untreated. Thirteen patients (62%) had associated medial collateral ligament (MCL) injuries. Mean follow-up was 2.6 years. VAS at rest and with activity improved by 2.1 points (P < .001) and 3.1 points (P = .017) after surgery. The mean postoperative Tegner activity score was 6.4, and the mean IKDC score was 83.2 at final follow-up. Reoperation was required in 5 patients (23.8%), and the surgical treatment failed in 1 patient (4.7%).

Conclusions

Double radial tears of the LM are uncommon injuries that occur in the setting of ACL tears, usually combined with MCL injury. The variety of surgical treatment techniques have a low failure rate at short-term follow-up. Patients tend to have good clinical outcomes with improvement in pain and overall function after surgically treating these injuries with simultaneous ACL reconstruction.

Level of Evidence

Level IV, therapeutic study, case series

All-Inside Repair for Radial Tear at the Posterior Horn of the Lateral Meniscus: A Figure-8 Suture Technique

Arthroscopic suture repair for a radial tear at the posterior horn of the lateral meniscus poses a technical procedure for surgeons. We describe an all-inside repair technique using all-inside meniscal repair devices without adding any accessory portals. This simple technique provides precise reduction and stabilization of the meniscus by pinching 2 all-inside vertical sutures consecutively across the tear site.

H-Plasty Repair Technique Improved Tibiofemoral Contact Mechanics After Repair for Adjacent Radial Tears of Posterior Lateral Meniscus Root: A Biomechanical Study

PURPOSE

To compare the time-zero tibiofemoral contact mechanics among the 4 different suturing repairs: transtibial pullout suture repair, suture anchor repair, side-to-side repair, and H-plasty repair.

METHODS

Twenty-four human cadaveric knees were included. Each lateral meniscus condition (intact, radial tear, and repair) was tested under a 1000-N axial compressive load at 0°, 30°, 60°, and 90° of flexion. Four different repair techniques, transtibial pullout, suture anchor, side-to-side, and H-plasty repair technique, were tested. Tibiofemoral mean and peak contact pressure and contact area in the lateral and medial compartments were measured by Tekscan sensors.

RESULTS

Radial tears adjacent to the posterior lateral meniscus root produced significantly decreased contact area and increased mean and peak contact pressures in the lateral compartment across all angles (P < .05). All repair groups could improve the contact mechanics relative to the torn condition (P < .05), but only H-plasty repair showed no significant difference in the mean and peak contact pressure and contact area compared with that of the intact state at all flexion angles (P > .05).

CONCLUSIONS

The results showed that the tibiofemoral contact mechanics after adjacent radial tears of the posterior lateral meniscal root were improved to the intact level by H-plasty repair at time-zero. The additional vertical mattress sutures act as "stabilizers" to provide a more stable environment in distributing vertical tibiofemoral pressure. The other 3 repair techniques also significantly improved lateral tibiofemoral contact mechanics relative to the corresponding tear conditions.

CLINICAL RELEVANCE

The results of this study suggest that H-plasty repair can restore the biomechanical properties to the intact state. Since it was a time-zero cadaveric study, the results should be carefully used in clinical practices.

Higher Incidence of Complete Lateral Meniscal Root Tears in Revision Compared With Primary Anterior Cruciate Ligament Reconstruction

Purpose

To evaluate the incidence of complete lateral meniscal posterior root tears (LMPRTs) repaired at revision as compared with primary anterior cruciate ligament (ACL) reconstruction (PACLR) and to determine whether other demographic or surgical characteristics were associated with LMPRTs needing repair.

Methods

A chart review was performed to identify the PACLR and revision ACL reconstruction (RACLR) cohorts. Demographic and surgical characteristics were recorded. Cases with concurrent lateral meniscal posterior root repair were identified. Cases were classified as acute (<5 months) or chronic (>5 months) based on the time from reported injury to surgery. Tunnel malposition in revision cases was recorded if either tunnel or both tunnels were malpositioned on radiographs and magnetic resonance imaging.

Results

Data from 167 cases, 140 PACLR and 27 RACLR cases, were included. The cohorts had similar demographic characteristics including age, sex, and lateral meniscal injury. The overall incidence of lateral meniscal root repair in ACL reconstruction patients was 12.6% (21 of 167 patients). The incidence of LMPRT repair was 7.1% (10 of 140 patients) in the PACLR cohort versus 40.7% (11 of 27 patients) in the RACLR cohort. The revision cohort was significantly more likely to have a chronic injury (66.7% [18 of 27 patients] vs 31.4% [44 of 140 patients]). The most significant predictor of concurrent lateral meniscal posterior root repair was RACLR versus PACLR for both univariate and multivariate logistic regression analyses (χ² = 20.603; P < .0001; odds ratio, 13.887; 95% confidence interval, 1.531-125.993). Analysis of tunnel positions for the revision group revealed that PACLR tunnel malposition was a significant predictor of LMPRTs (χ² = 4.91, P = .027).

Conclusions

Complete LMPRTs warranting repair are encountered with a significantly greater frequency at RACLR as compared with PACLR. The overall incidence of LMPRT repair at RACLR is high. In this cohort, LMPRT repair in RACLR cases was associated with tunnel malposition of the PACLR.

Level of Evidence

Level III, retrospective cohort study.