The Lateral Femoral Notch Sign Is Correlated With Increased Rotatory Laxity After Anterior Cruciate Ligament Injury: Pivot Shift Quantification With A Surgical Navigation System

The presence of a deep lateral femoral notch sign in ACL-injured patients is associated with a 2.7° steeper posterior tibial slope and a 19% higher frequency of lateral meniscal injuries

PURPOSE

The purpose of this study was to study the relationship between the presence of a deep lateral femoral notch sign (DLFNS) in anterior cruciate ligament (ACL)-injured patients and a higher posterior lateral tibial slope (LPTS), a reduced meniscal bone angle (MBA), a higher LPTS/MBA ratio and a higher incidence of concomitant injuries in primary ACL tears.

METHODS

A retrospective case-control study was performed in patients submitted to primary ACL reconstruction with an available preoperative magnetic resonance imaging (MRI) scan. Patients with ACL tears and a femoral impactation with a depth ≥2 mm were assorted to the DLFNS group and patients with ACL tear and without a DLFNS to the control group. LPTS and MBA were measured in MRI. The presence of concomitant injuries (meniscal, posterior cruciate ligament, medial collateral ligament, lateral collateral ligament and bone injuries) was assessed in MRI. Quantitative data are presented in the median ± interquartile range (IQR).

RESULTS

There were 206 patients included in the study, with 46 patients assorted to the DLFNS group and 160 patients to the control group. In the DLFNS group, the median LPTS was 6.7° (IQR: 4.0-8.2) versus 4.0° in the control group (IQR: 2.2-6.5) (p = 0.003). The LPTS/MBA ratio was significantly higher in the DLFNS group, with a median of 0.32 (IQR: 0.19-0.44), in comparison to the control group, with a median of 0.19 (IQR: 0.11-0.31) (p < 0.001). The multivariable logistic regression analysis showed that the LPTS is an independent risk factor to having a DLFNS (odds ratio [OR] = 1.161; 95% confidence interval [CI]: 1.042-1.293, p = 0.007). There was a higher incidence of concomitant lateral meniscal injuries in the DLFNS group (67% vs. 48%, p = 0.017).

CONCLUSIONS

In patients with ACL tears, the presence of a DLFNS is associated with a steeper lateral posterior tibial slope, as well as a higher incidence of concomitant lateral meniscal injuries.

LEVEL OF EVIDENCE

Level III.

Reduction of a Depressed Femoral Lateral Notch at the Time of Lateral Extra-articular Tenodesis

We present a surgical technique to address severe lateral femoral notch depressions using a small extension in the lateral approach for Lemaire extra-articular tenodesis in anterior cruciate ligament reconstruction. Through this approach, the surgeon is able to obtain good exposure of the lateral femoral condyle, with straightforward access for subchondral reduction, without adding any significant morbidity.

Could medial femoral notching be a marker in posterolateral corner injuries?

INTRODUCTION

Posterolateral corner (PLC) injuries constitute 16 % of all knee ligament injuries and are often seen with other ligamentous injuries. PLC injuries can be overlooked. If left untreated, other ligamentous reconstructions are at risk, residual laxity may occur, and early osteoarthritis may result.

MATERIALS AND METHODS

Patients diagnosed with PLC injury and who underwent surgical treatment between November 2018 and November 2022 were retrospectively analyzed. Two groups were formed 44 PLC patients with a concomitant ligament injury and 50 patients with an isolated ACL injury (control group). Preoperative MRI findings and arthroscopic surgery findings of the patients were evaluated. Medial femoral condyle notching sign (MFNS) and lateral femoral condyle notching sign (LFNS) data were obtained from preoperative MRI sections. If the lesion depth was less than 1.5 mm, it was not considered a notching sign.

RESULTS

In group 1, there were 44 patients with PLC injuries accompanied by other ligamentous injuries. In group 2, there were 50 patients with isolated ACL injuries not accompanied by other ligamentous injuries. Medial femoral notching sign (MFNS) was higher in Group 1 (p < 0.00001). The lateral femoral notching sign (LFNS) was higher in Group 2 (p:0.023).

CONCLUSION

PLC injuries are difficult to diagnose. MFNS is a finding that may facilitate diagnosis in PLC injuries.

The influence of distribution, severity and volume of posttraumatic bone bruise on functional outcome after ACL reconstruction for isolated ACL injuries

INTRODUCTION

Posttraumatic MRI of ACL tears show a high prevalence of bone bruise (BB) without macroscopic proof of chondral damage. Controversial results are described concerning the association between BB and outcome after ACL tear. Aim of this study is to evaluate the influence of distribution, severity and volume of BB in isolated ACL injuries on function, quality of life and muscle strength following ACL reconstruction (ACLR).

MATERIALS AND METHODS

MRI of n = 122 patients treated by ACLR without concomitant pathologies were evaluated. BB was differentiated by four localizations: medial/lateral femoral condyle (MFC/LFC) and medial/lateral tibial plateau (MTP/LTP). Severity was graded according to Costa-Paz. BB volumes of n = 46 patients were quantified (software-assisted volumetry). Outcome was measured by Lysholm Score (LS), Tegner Activity Scale (TAS), IKDC, isokinetics and SF-36. Measurements were conducted preoperatively (t0), 6 weeks (t1), 26 weeks (t2) and 52 weeks (t3) after ACLR.

RESULTS

The prevalence of BB was 91.8%. LTP was present in 91.8%, LFC 64.8%, MTP 49.2% and MFC 28.7%. 18.9% were classified Costa-Paz I, 58.2% II and 14.8% III. Total BB volume was 21.84 ± 15.27 cm3, the highest value for LTP (14.31 ± 9.93 cm3). LS/TAS/IKDC/SF-36/isokinetics improved significantly between t0-t3 (p < 0.001). Distribution, severity and volume had no influence on LS/TAS/IKDC/SF-36/isokinetics (n.s.).

CONCLUSIONS

No impact of BB after ACLR on function, quality of life and objective muscle strength was shown, unaffected by concomitant pathologies. Previous data regarding prevalence and distribution is confirmed. These results help surgeons counselling patients regarding the interpretation of extensive BB findings. Long-time follow-up studies are mandatory to evaluate an impact of BB on knee function due to secondary arthritis.

Impaction Fractures of the Lateral Femoral Condyle Related to Anterior Cruciate Ligament Injury: A Scoping Review Concerning Diagnosis, Prevalence, Clinical Importance, and Management

Background

During pivot-shift anterior cruciate ligament (ACL) injury, bone bruises or impaction fractures of the lateral femoral condyle (LFC-IF) may occur due to impaction between the posterior part of the lateral tibial plateau and anterocentral part of the LFC. The purpose of the study was to systematically review the literature concerning the diagnosis, prevalence, clinical importance, and management of LFC-IF occurring during ACL injuries.

Methods

Included were studies concerning impaction fractures of the anterocentral part of the LFC occurring during ACL injuries. Studies concerning only bone bruises or cartilage lesions, without subchondral bone impaction, were not included. A search was performed in Medline and Scopus databases, with final search in May 2022. A secondary search was conducted within the bibliographies of included articles and using "Cited In" option. Two authors independently extracted data in three domains: study design, LFC-IF characteristics, and LFC-IF importance and management.

Results

A total of 35 studies were included for review with several studies reporting on multiple domains. Summarily, 31 studies were on the diagnosis and prevalence, 19 studies reported on the clinical importance, and 4 studies reported on the management of LFC-IF.

Conclusions

A LFC-IF occurs due to the pivot-shift mechanism of ACL injury. Its radiological feature is defined as an impaction of terminal sulcus deeper than 1 mm and is present in up to 52% of patients with a torn ACL. An LFC-IF causes injury to the cartilage, probably leads to its progressive degeneration, and is significantly associated with an increased risk of a lateral meniscus injury. A large LFC-IF might be associated with greater rotational knee instability. Although several techniques of LFC-IF treatment were proposed, none of them has been evaluated on a large cohort of patients to date.

Greater Knee Rotatory Instability After Posterior Meniscocapsular Injury Versus Anterolateral Ligament Injury: A Proposed Mechanism of High-Grade Pivot Shift

Background

For anterolateral rotatory instability as a result of secondary soft tissue injuries in anterior cruciate ligament (ACL)-deficient knees, there is increasing interest in secondary stabilizers to prevent internal rotation (IR) of the tibia.

Purpose

To determine which secondary stabilizer is more important in anterolateral rotatory instability in ACL-deficient knees.

Study Design

Controlled laboratory study.

Methods

The lower extremities of 10 fresh-frozen cadavers (20 extremities) without anterior-posterior or rotational instability were included. Matched-pair randomization was performed, with each side per specimen assigned to 1 of 2 groups. In group 1, the ACL was sectioned, followed by the anterolateral ligament (ALL); in group 2, the ACL was sectioned, followed by sequential sectioning of the posterolateral meniscocapsular complex (PLMCC) and posteromedial meniscocapsular complex (PMMCC). The primary outcome was the change in relative tibial IR during a simulated pivot-shift test with 5 N·m of IR torque and 8.9 N of valgus force. The secondary outcomes were the International Knee Documentation Committee grade in the pivot-shift test and the incidence of the grade 3 pivot shift.

Results

In group 1, compared with baseline, the change in relative tibial IR at 0° of knee flexion was 1.4° (95% CI, -0.1° to 2.9°; P = .052) after ALL release. In group 2, it was 2.5° (95% CI, 0.4° to 4.8°; P = .007) after PLMCC release and 4.1° (95% CI, 0.5° to 7.8°; P = .017) after combined PLMCC and PMMCC release. Combined PLMCC and PMMCC release resulted in greater change of tibial IR with statistical significance at 0°, 15°, and 30° of knee flexion (P = .008, .057, and .004, respectively) compared with ALL release. The incidence of grade 3 pivot shifts was 10% in group 1 and 90% in group 2.

Conclusion

Posterior meniscocapsular laxity caused an increase in relative tibial IR as much as ALL injury in ACL-deficient knees in our simulated laboratory test, and greater anterolateral rotatory instability occurred with posterior meniscocapsular injury compared with ALL injury.

Clinical Relevance

Repair of the injured posterior meniscocapsular complex may be an important treatment option for reducing anterolateral rotatory instability in the ACL-deficient knee.

The posterior cruciate ligament index as a reliable indirect sign of anterior cruciate ligament rupture is associated with the course of knee joint injury

PURPOSE

The objective of this study was to clarify the clinical value of the posterior cruciate ligament index (PCLI) in anterior cruciate ligament (ACL) rupture, to explore the relationship between the PCLI and course of disease, and to identify the influencing factors of the PCLI.

METHODS

The PCLI was defined a quotient of the X (the tibial and femoral PCL attachments) and the Y (the maximum perpendicular distance from X to the PCL). A total of 858 patients were enrolled in this case-control study, including 433 patients with ACL ruptures who were assigned to the experimental group and 425 patients with meniscal tears (MTs) who were allocated to the control group. Some patients in the experimental group have collateral ligament rupture (CLR). Information, such as the patient's age, sex, and course of disease, was recorded. All patients underwent magnetic resonance imaging (MRI) preoperatively, and the diagnosis was confirmed with the aid of arthroscopy. The PCLI and the depth of the lateral femoral notch sign (LFNS) were calculated based on the MRI findings, and the characteristics of the PCLI were explored.

RESULTS

The PCLI in the experimental group (5.1 ± 1.6) was significantly smaller than that in the control group (5.8 ± 1.6) (P < 0.05). The PCLI gradually decreased with time and was only 4.8 ± 1.4 in patients in the chronic phase (P < 0.05). This change was not due to the decrease in X but rather the increase in Y. The results also showed that the PCLI was not related to the depth of the LFNS or injuries of other structures in the knee joint. Furthermore, when the optimal cut-off point of the PCLI was 5.2 (area under the curve = 71%), the specificity and the sensitivity were 84% and 67%, respectively, but the Youden index was just 0.3 (P < 0.05).

CONCLUSION

The PCLI decreases due to the increase in Y instead of the decrease in X with time, especially in the chronic phase. The change in X in this process may be offset during imaging. In addition, there are fewer influencing factors that lead to changes in the PCLI. Therefore, it can be used as a reliable indirect sign of ACL rupture. However, it is difficult to quantify the diagnostic criteria of the PCLI in clinical practice. Thus, the PCLI as a reliable indirect sign of ACL rupture is associated with the course of knee joint injury, and it can be used to describe the instability of the knee joint.

LEVELS OF EVIDENCE

III.

The lateral femoral notch sign decreases in paediatric patients following anterior cruciate ligament reconstruction

INTRODUCTION

Anterior cruciate ligament (ACL) ruptures are common amongst paediatric patients, especially those participating in competitive sports. While magnetic resonance imaging (MRI) is typically used to confirm the diagnosis, certain radiologic findings can be indicative of an ACL tear, including a lateral femoral notch sign (LFNS) > 1.5 mm (mm). No study has focussed on understanding the resolution pattern of the LFNS in paediatric patients following ACL reconstruction (ACLR). The aim of this study is to determine whether the depth of the LFNS regresses following ACLR. The authors hypothesize that following ACLR, the LFNS will resolve.

METHODS

All patients who were treated for acute ACL rupture by one of two paediatric orthopaedic surgeons between 2015 and 2020 were collected; 321 patients with the age of 5-18 were collected. Patients were excluded if they underwent previous ipsilateral knee surgeries and if they did not have pre-operative knee radiographs; 274 patients met inclusion criteria. LFNS was measured on pre-operative (PreOp) and most recent post-operative (PostOp) radiographs. A comparison cohort of patients with an LFNS <1.5 mm matched by age within 1.5 years, sex, and laterality was also collected. The median difference was calculated by taking the difference between PreOp LFNS and PostOp LFNS of each participant and finding the median of those values.

RESULTS

A total of 274 pre-operative radiographs were analysed for an LFNS depth >1.5 mm. Seventeen radiographs met these criteria with a median age of 16.3 years and a median depth of 1.70 mm. Of the 17 radiographs, 8 (47.1%) of participants were skeletally immature. The median LFNS depth at most recent follow-up and median percent decrease were 1.50 mm and 28%, respectively. Only 11.8% of patients demonstrated no change in LFNS depth from PreOp to PostOp imaging. Wilcoxon signed-rank test indicated that the PreOp LFNS was significantly greater than the PostOp LFNS (p < 0.001). Mann-Whitney U tests with cases and the comparison cohort demonstrated no difference in the percent decrease (p = 0.106).

CONCLUSION

This study sought to understand the resolution of the LFNS depth following initial ACL rupture. At a median of 7.67 months following ACLR, the LFNS depth decreased significantly by 0.60 mm. These findings suggest that following ACL rupture, the paediatric LFNS has the potential to resolve. Future studies should aim to further assess the resolution pattern of the LFNS with advanced imaging, such as MRI.

Posterior tibial plateau impaction fractures are not associated with increased knee instability: a quantitative pivot shift analysis

PURPOSE

This study aimed to evaluate posterolateral tibial plateau impaction fractures and how they contribute to rotatory knee laxity using quantitative pivot shift analysis. It was hypothesised that neither the presence of nor the degree of involvement of the plateau would affect rotatory knee laxity in the ACL-deficient knee.

METHODS

A retrospective review of prospectively collected data on 284 patients with complete anterior cruciate ligament (ACL) injuries was conducted. Posterolateral tibial plateau impaction fractures were identified on preoperative MRI. The patients were divided into two cohorts: "fractures" or "no fractures". The cohort with fractures was further categorised based on fracture morphology: "extra-articular", "articular-impaction", or "displaced-articular fragment". All data were collected during examination under anaesthesia performed immediately prior to ACL reconstruction. This included a standard pivot shift test graded by the examiner and quantitative data including anterior tibial translation (mm) via Rolimeter, quantitative pivot shift (QPS) examination (mm) via PIVOT tablet technology, and acceleration (m/sec²) during the pivot shift test via accelerometer. Quantitative examinations were compared with the contralateral knee.

RESULTS

There were 112 patients with posterolateral tibial plateau impaction fractures (112/284, 39%). Of these, 71/112 (63%) were "extra-articular", 28/112 (25%) "articular-impaction", and 13/112 (12%) "displaced-articular". Regarding the two groups with or without fractures, there was no difference in subjective pivot shift (2 ± 0 vs 2 ± 0, respectively,  n.s.), QPS (2.4 ± 1.6 mm vs 2.7 ± 2.2 mm, respectively, n.s.), anterior tibial translation measurements (6 ± 3 mm vs 5 ± 3 mm, respectively, n.s.), or acceleration of the knee during the pivot (1.7 ± 2.3 m/s² vs 1.8 ± 3.1 m/s², respectively, n.s.). When the fractures were further subdivided, subgroup analysis revealed no significant differences noted in any of the measured examinations between the fracture subtypes.

CONCLUSION

This study showed that the posterolateral tibial plateau impaction fractures are commonly encountered in the setting of ACL tears; however, contrary to previous reports, they do not significantly increase rotatory knee laxity. This suggests that this type of concomitant injury may not need to be addressed at the time of ACL reconstruction.

LEVEL OF EVIDENCE

Level III.

The anterior cruciate ligament injury severity scale (ACLISS) is an effective tool to document and categorize the magnitude of associated tissue damage in knees after primary ACL injury and reconstruction

PURPOSE

To develop a tool allowing to classify the magnitude of structural tissue damage occurring in ACL injured knees. The proposed ACL Injury Severity Scale (ACLISS) would provide an easy description and categorization of the wide spectrum of injuries in patients undergoing primary ACL reconstruction, reaching from isolated ACL tears to ACL injuries with a complex association of combined structural damage.

METHODS

A stepwise approach was used to develop the ACLISS. The eligibility of each item was based on a literature search and a consensus between the authors after considering the diagnostic modalities and clinical importance of associated injuries to the menisci, subchondral bone, articular cartilage or collateral ligaments. Then, a retrospective analysis of associated injuries was performed in 100 patients who underwent a primary ACL reconstruction (ACLR) by a single surgeon. This was based on acute preoperative MRI (within 8 weeks after injury) as well as intraoperative arthroscopic findings. Depending on their prevalence, the number of selected items was reduced. Finally, an analysis of the overall scale distribution was performed to classify the patients according to different injury profiles.

RESULTS

A final scoring system of 12 points was developed (12 = highest severity). Six points were attributed to the medial and lateral tibiofemoral compartment respectively. The amount of associated injuries increased with ACLISS grading. The median scale value was 4.5 (lower quartile 3.0; higher quartile 7.0). Based on these quartiles, a score < 4 was considered to be an injury of mild severity (grade I), a score between ≥ 4 and ≤ 7 was defined as moderately severe (grade II) and a score > 7 displayed the most severe cases of ACL injuries (grade III). The knees were graded ACLISS I in 35%, ACLISS II in 49% and ACLISS III in 16% of patients. Overall, damage to the lateral tibiofemoral compartment was predominant (p < 0.01), but a proportional increase of tissue damage could be observed in the medial tibiofemoral compartment with the severity of ACLISS grading (p < 0.01).

CONCLUSIONS

The ACLISS allowed to easily and rapidly identify different injury severity profiles in patients who underwent primary ACLR. Injury severity was associated with an increased involvement of the medial tibiofemoral compartment. The ACLISS is convenient to use in daily clinical practice and represents a feasible grading and documentation tool for a reproducible comparison of clinical data in ACL injured patients.

LEVEL OF EVIDENCE

Level III.

The lateral femoral notch sign and coronal lateral collateral ligament sign in magnetic resonance imaging failed to predict dynamic anterior tibial laxity

Purpose

To investigate the relationship between the lateral femoral notch sign as well as the coronal lateral collateral ligament (LCL) sign and anterior tibial translation using the GNRB arthrometer in patients with anterior cruciate ligament (ACL) injuries.

Methods

Forty-six patients with ACL injuries were retrospectively included from May 2020 to February 2022; four patients were excluded due to incomplete data. Magnetic resonance imaging (MRI) were reviewed for the lateral femoral notch sign and the coronal LCL sign. The GNRB arthrometer was used to evaluate the dynamic anterior tibial translation of the knee, and the side-to-side differences (SSDs) in tibial translation between the injured knee and healthy knee were calculated at different force levels. Two types of slopes for displacement-force curves were acquired.

Results

Six patients (14.3%) had the positive lateral femoral notch sign (notch depth > 2.0 mm), and 14 patients (33.3%) had the positive coronal LCL sign. The SSD of the anterior tibial translations under different loads as well as the slopes of displacement-force curves were the same in the positive and negative notch sign groups (p all > 0.05) and between the positive and negative coronal LCL sign groups (p all > 0.05). Meanwhile, the measured notch depth and notch length were also not significantly correlated with the anterior tibial translation SSD in the GNRB.

Conclusion

The presence of the lateral femoral notch sign and the coronal LCL sign did not indicate greater dynamic tibial laxity as measured using the GNRB.

Current trends in the anterior cruciate ligament part 1: biology and biomechanics

A trend within the orthopedic community is rejection of the belief that "one size fits all." Freddie Fu, among others, strived to individualize the treatment of anterior cruciate ligament (ACL) injuries based on the patient's anatomy. Further, during the last two decades, greater emphasis has been placed on improving the outcomes of ACL reconstruction (ACL-R). Accordingly, anatomic tunnel placement is paramount in preventing graft impingement and restoring knee kinematics. Additionally, identification and management of concomitant knee injuries help to re-establish knee kinematics and prevent lower outcomes and registry studies continue to determine which graft yields the best outcomes. The utilization of registry studies has provided several large-scale epidemiologic studies that have bolstered outcomes data, such as avoiding allografts in pediatric populations and incorporating extra-articular stabilizing procedures in younger athletes to prevent re-rupture. In describing the anatomic and biomechanical understanding of the ACL and the resulting improvements in terms of surgical reconstruction, the purpose of this article is to illustrate how basic science advancements have directly led to improvements in clinical outcomes for ACL-injured patients.Level of evidenceV.

Severe bicompartmental bone bruise is associated with rotatory instability in anterior cruciate ligament injury

PURPOSE

The presence and severity of bone bruise is more and more investigated in the non-contact anterior cruciate ligament (ACL) injury context. Recent studies have advocated a correlation between bone bruise and preoperative knee laxity. The aim of the present study was to investigate the correlation between bone bruise and preoperative rotatory knee laxity.

METHODS

Twenty-nine patients (29.1 ± 9.8 years) with MRI images at a maximum of 3 months after ACL injury (1.6 ± 0.8 months) were included. The bone bruise severity was evaluated according to the International Cartilage Repair Society (ICRS) scale for lateral femoral condyle, lateral tibial plateau, medial femoral condyle, and medial tibial plateau. The intraoperative rotational knee laxity was evaluated through a surgical navigation system in terms of internal-external rotation at 30° and 90° of knee flexion (IE30, IE90) and internal-external rotation and acceleration during pivot-shift test (PS IE, PS ACC). The KOOS score was also collected. The association between ICRS grade of bone bruise and rotational laxity or KOOS was investigated.

RESULTS

Significant correlation (p < 0.05) was found between the bone bruise severity on the medial tibial plateau and rotational laxity (IE90, PS IE, and PS ACC) and between the severity of bone bruise on femoral lateral condyle and KOOS-Symptoms sub-score. The presence of bone bruise on the medial tibial plateau was significantly associated with a lateral femoral notch sign > 2 mm (very strong odds ratio). No kinematical differences were found between none-to-deep and extensive-generalized lateral bone bruise, while higher IE30 and IE90 were found in extensive-generalized bicompartmental bone bruise than isolated extensive-generalized lateral bone bruise.

CONCLUSION

A severe bicompartmental bone bruise was related to higher rotatory instability in the intraoperative evaluation of ACL deficient knees. The severity of edema on the medial tibial plateau was directly correlated with higher intraoperative pivot shift, and the size of edema on the lateral femoral condyle was associated with lower preoperative clinical scores.

LEVEL OF EVIDENCE

Level II.

Lateral femoral notch sign and posterolateral tibial plateau fractures and their associated injuries in the setting of an anterior cruciate ligament rupture

INTRODUCTION

ACL injury is one of the most common injuries of the knee joint in sports. As accompanying osseous injuries of the ACL rupture a femoral impression the so-called lateral femoral notch sign and a posterolateral fracture of the tibial plateau are described. However, frequency, concomitant ligament injuries and when and how to treat these combined injuries are not clear. There is still a lack of understanding with which ligamentous concomitant injuries besides the anterior cruciate ligament injury these bony injuries are associated.

MATERIALS AND METHODS

One hundred fifteen MRI scans with proven anterior cruciate ligament rupture performed at our center were retrospectively evaluated for the presence of a meniscus, collateral ligament injury, a femoral impression, or a posterolateral impression fracture. Femoral impressions were described according to their local appearance and posterolateral tibial plateau fractures were described using the classification of Menzdorf et al. RESULTS: In 29 cases a significant impression in the lateral femoral condyle was detected. There was a significantly increased number of lateral meniscal (41.4% vs. 18.6% p = 0.023) and medial ligament (41.4% vs. 22.1%; p = 0.040) injuries in the group with a lateral femoral notch sign. 104 patients showed a posterolateral bone bruise or fracture of the tibial plateau. Seven of these required an intervention according to Menzdorf et al. In the group of anterior cruciate ligament injuries with posterolateral tibial plateau fracture significantly more lateral meniscus injuries were seen (p = 0.039).

CONCLUSION

In the preoperative planning of ACL rupture accompanied with a positive femoral notch sign, attention should be paid to possible medial collateral ligament and lateral meniscus injuries. As these are more likely to occur together. A posterolateral impression fracture of the tibial plateau is associated with an increased likelihood of the presence of a lateral meniscal injury. This must be considered in surgical therapy and planning and may be the indication for necessary early surgical treatment.

Editorial Commentary: The Importance of Bony Morphology in the Anterior Cruciate Ligament-Injured Patient

The outcome of anterior cruciate ligament (ACL) surgery depends on many factors. Successful ACL surgery includes evaluating patients' characteristics and addressing all the underlying knee pathologies, including the meniscus tears and ramp lesions. In recent years, there has been a growing interest in ramp lesions as well as the role that bony morphology plays in predisposing patients to ACL injury and failed ACL surgery. Not only pathologic but also physiologic variations in bony morphology like tibial slope and lateral femoral condyle ratio have been correlated with clinical outcomes, failure rates, rotatory instability, and even lesions to the contralateral knee. Evaluating each patient's specific anatomy is recommended when customizing ACL surgery. With further research and increased awareness of relevant bony parameters, we will be able to improve our ability to prevent injury, increase the diagnostic accuracy of associated lesions, and tailor surgery to improve the outcomes and reduce failure rates.

[Research progress of lateral femoral notch sign in diagnosis of anterior cruciate ligament rupture]

Objective

To summarize the relationship between lateral femoral notch sign (LFNS) and anterior cruciate ligament (ACL) rupture.

Methods

The relevant literature of LFNS at home and abroad in recent years was retrospectively reviewed, and its mechanism, diagnostic criteria and influencing factors in diagnosis of ACL rupture were summarized and analyzed.

Results

The LFNS is associated with rotational stability of the knee. As an indirect sign of ACL rupture, the LFNS has high clinical diagnostic value, especially the diagnosis of ACL rupture with lateral meniscus injury.

Conclusion

The diagnostic criteria and influencing factors of LFNS in diagnosis of ACL rupture are still unclear and controversial, which needs further study.

Editorial Commentary: Outcomes After Anterior Cruciate Ligament Reconstruction Are Defined by Individual Anatomy, Including Both Soft Tissue and Bone Morphology: It's All Important

Well-designed studies add to our understanding of the anatomy, biology, biomechanics, and outcomes of the anterior cruciate ligament (ACL) following injury. Despite improvements in ACL treatment, we are still unable to exactly restore the individually unique function of the native ACL due to the complexity of knee physiology. The ACL is a dynamic structure with a rich neurovascular supply, distinct bundles, and 3-dimensional architecture that function in synergy with the bony morphology to facilitate healthy knee kinematics. Furthermore, the ACL exhibits a wide range of natural, anatomic variation. Since anatomic ACL reconstruction has been defined as functional restoration of the ACL to its native dimensions and collagen orientation, in addition to restoring the native footprint, it is important to restore the native size of the ACL, as the size of the tibial insertion site can vary by a factor of 3 from patient to patient. Moreover, variations in ACL soft tissue reflect differences in bony morphology. Bony morphology influences the static and dynamic biomechanics of the knee. Several bony morphologic factors influence the outcomes following ACL reconstruction, including posterior tibial slope, femoral condylar offset ratio, and notch shape. Morphologic differences that reflect pathologic states, such as the lateral notch sign and posterolateral plateau fracture, have been shown to be associated with greater grade instability. To respect the unique nature of each patient during surgical treatment, it is necessary to perform an individualized, anatomic, and value-based ACL reconstruction.