Incidence of Displaced Posterolateral Tibial Plateau and Lateral Femoral Condyle Impaction Fractures in the Setting of Primary Anterior Cruciate Ligament Tear

Incidence and Characteristics of Knee Ligament and Meniscal Injuries in Patients With Posterolateral Tibial Plateau Fractures

Background

Anterior cruciate ligament (ACL) tears are commonly seen with concomitant injuries to the posterolateral tibial plateau, while the occurrence of ACL injuries in posterolateral tibial plateau fractures (PTPFs) remains unclear.

Purpose

To (1) explore the incidence of knee ligament (anterior or posterior cruciate ligament, medial or lateral collateral ligament) and medial or lateral meniscus injuries in patients with PTPF and (2) find reliable PTPF-related parameters to predict the risk of knee ligament and meniscal injuries.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Patients diagnosed with PTPF who had computed tomography and magnetic resonance imaging (MRI) data were identified. Morphological parameters of the PTPF were measured on sagittal computed tomography images. Knee ligament and meniscal injuries were assessed using MRI. The association of ACL injuries with meniscal injuries was analyzed. Receiver operating characteristic (ROC) analysis was used to determine the value and cutoff point of the PTPF morphological parameters for diagnosing complete in-substance ACL tears.

Results

Overall, 113 patients with PTPF were included. ACL injuries were present in 94 (83.2%) patients, including 43 (38.1%) avulsion fractures and 28 (24.8%) complete in-substance tears. Patients with in-substance ACL tears had a higher incidence of lateral meniscus posterior horn tears compared with the other patients (PBonferroni < .001). ROC analysis revealed that both the fracture depression angle (cutoff point, 25.5°) and the posterior articular surface loss percentage (cutoff point, 37.5%) had a sensitivity >90% and a specificity >80% for the diagnosis of complete in-substance ACL tears.

Conclusion

ACL injuries were seen in 83.2% of the study patients. Complete in-substance ACL tears were associated with an increased incidence of lateral meniscus posterior horn tears. Among PTPF parameters, fracture depression angle and posterior articular surface loss percentage showed a high predictive value for the presence of complete in-substance ACL tears, thereby reducing delays in diagnosis and treatment.

Effectiveness of bone grafting versus cannulated screw fixation in the treatment of posterolateral tibial plateau compression fractures with concomitant ACL injury: a comparative study

BACKGROUND

Posterolateral tibial plateau compression fractures (PTPCF) are one of the significant factors leading to knee instability and anterior cruciate ligament (ACL) reconstruction failure. The effectiveness of fixation for such cases without the use of metal implants remains inconclusive. The aim of this study is to investigate whether the fixation with isolated bone grafting is stable enough for the treatment of PTPCF with concomitant ACL injuries.

METHODS

This retrospective study analyzed patients treated for concomitant ACL injuries and PTPCF in authors' institution. A total of 53 patients (21 males and 32 females) with an average age of 47.43 ± 14.71 years were included. Patient data were collected, including factors leading to injury, affected side, height, weight, and basic medical history. The posterior inclination angle and the lateral tibial plateau lateral inclination angle were measured to evaluate the fixation stability. Rasmussen functional score and HSS score were used to assess the knee functional recovery.

RESULTS

The bone grafting group achieved satisfactory levels of Rasmussen score (28.22 ± 0.85) and HSS knee joint function scores (95.57 ± 1.97). The cannulated screw fixation group had a Rasmussen knee joint function score of 28.70 ± 0.92 and a HSS knee joint function score of 96.07 ± 1.93. No statistically significant difference was found (P > 0.05). The cannulated screw fixation group had a mean posterior inclination angle reduction loss of 0.20° ± 1.11°, while the bone grafting group had a reduction loss of 0.18° ± 1.01°, with no statistically significant difference (P > 0.05). The cannulated screw fixation group had a lateral inclination angle reduction loss of 0.01° ± 0.37°, and the bone grafting group had a reduction loss of 0.03° ± 0.43°, with no statistically significant difference (P > 0.05).

CONCLUSION

The use of bone grafting for fixation of PTPCF with accompanying ACL injuries demonstrated no substantial disparities in knee joint function. In cases of simple PTPCF, filling and compacting the bone defect underneath the tibial plateau fracture fragment can yield satisfactory fixation, obviating the necessity for supplementary cannulate screw fixation.

Clinical Analysis of the Frosch Approach in the Treatment of Posterolateral Tibial Plateau Fractures Combined with Lateral Tibial Plateau Fractures

OBJECTIVE

The treatment of posterolateral tibial plateau fractures is difficult, and providing sufficient exposure and effective fixation is a challenge. There is great controversy regarding the surgical approach for posterolateral tibial plateau fractures. The purpose of the study was to investigate the clinical effects of open reduction and internal fixation using the Frosch approach for the treatment of posterolateral tibial plateau fractures combined with lateral tibial plateau fractures.

METHODS

Data from 19 patients with posterolateral tibial plateau fractures combined with lateral tibial plateau fractures treated from May 2018 to January 2022 were retrospectively analyzed. There were nine men and 10 women, ranging in age from 22 to 62 years, with an average age of 45.6 years. All patients were treated using the Frosch approach. Under direct vision, the posterolateral and lateral fractures were reduced, and full bone grafting was performed. We reshaped the oblique "T" shaped plate for the distal radius and placed it on the posterolateral tibial plateau to fix the posterolateral fractures. The lateral inverted "L" shaped locking plate was placed on the lateral tibial plateau to fix the lateral tibial plateau fractures. Within 2 weeks after the operation, the patients were instructed to perform knee joint function exercises within 90°. At the last follow-up, the Rasmussen radiological criteria were used to evaluate the effectiveness of fracture reduction and fixation. And the knee joint function was evaluated using Rasmussen functional score.

RESULTS

The operation time ranged from 100 to 180 min, with an average of 134.2 min; intraoperative blood loss ranged from 20 to 150 mL, with an average of 66.8 mL. The follow-up duration ranged from 14 to 58 months, with an average of 36.2 months. There were no complications, such as vascular or nerve injury or incision infection. Fracture healing was achieved in all patients, and the healing time ranged from 10 to 14 weeks, with an average of 11.2 weeks. During the follow-up period, there was no loosening or breakage of the internal fixation, varus or valgus deformity of the knee joint, re-collapse of the articular surface, or instability of the knee joint. At the last follow-up, the effectiveness of fracture reduction and fixation was excellent in 13 patients and good in six patients. And the knee joint function was excellent in 17 patients and good in two patients.

CONCLUSION

The Frosch approach for open reduction and internal fixation in the treatment of posterolateral tibial plateau fractures combined with lateral tibial plateau fractures has a definite clinical benefit and is worthy of promotion and application.

3D printing combined with anteroposterior cannulated screws for the treatment of posterolateral tibial plateau fracture

PURPOSE

This study aimed to compare the effects of conventional surgery and three-dimension (3D) printing technology-assisted surgery in the treatment of posterolateral tibial plateau fractures (PTPF).

METHODS

A cohort of 61 patients afflicted with PTPF, spanning from June 2015 to October 2021, was enrolled. They were divided randomly into two groups: 31 cases of 3D printing group, 30 cases of conventional group. The personalized 3D-printed models were used to simulate the surgical procedures in 3D printing group. The demographic characteristics and clinical data were recorded, encompassing operation duration, intraoperative blood loss, intraoperative fluoroscopy shoots and fracture union time. The radiographic outcomes were gauged, encompassing tibiofemoral angle (FTA), tibial plateau angle (TPA), posterolateral slope angle (PSA) and Rasmussen's anatomical score. The functional outcomes were assessed at the 12-month postoperative juncture, encompassing range of motion, Hospital for Special Surgery (HSS) score and Rasmussen's functional score. Furthermore, fracture complications were evaluated,, encompassing infections, traumatic osteoarthritis, and delayed union.

RESULTS

The 3D printing group exhibited the operation time of 95.8 ± 30.2 min, intraoperative blood loss of 101.1 ± 55.3 ml, and intraoperative fluoroscopy shoots of 6.3 ± 2.3 times, while the conventional group recorded respective values of 115.5 ± 34.0 min, 137.0 ± 49.2 ml and 9.13 ± 2.5 times. Noteworthy disparities were evident between the conventional and 3D printing groups (p < 0.05). Furthermore, in comparison to the conventional group, the 3D printing group exhibited commendable radiological and functional outcomes both immediately and 12 months post-surgery, although statistical significance was not attained. Moreover, the 3D printing group experienced a paucity of complications compared to the conventional group, although without achieving statistical significance.

CONCLUSION

This study demonstrated the clinical feasibility of 3D printing combined with anteroposterior cannulated screws for the treatment of posterolateral tibial plateau fracture.

The "Bankart knee": high-grade impression fractures of the posterolateral tibial plateau lead to increased translational and anterolateral rotational instability of the ACL-deficient knee

PURPOSE

The aim of this biomechanical cadaver study was to evaluate the effects of high-grade posterolateral tibia plateau fractures on the kinematics of anterior cruciate ligament (ACL)-deficient joints; it was hypothesized that, owing to the loss of the integrity of the osseous support of the posterior horn of the lateral meniscus (PHLM), these fractures would influence the biomechanical function of the lateral meniscus (LM) and consequently lead to an increase in anterior translational and anterolateral rotational (ALR) instability.

METHODS

Eight fresh-frozen cadaveric knees were tested using a six-degree-of-freedom robotic setup (KR 125, KUKA Robotics, Germany) with an attached optical tracking system (Optotrack Certus Motion Capture, Northern Digital, Canada). After the passive path from 0 to 90° was established, a simulated Lachman test and pivot-shift test as well as external rotation (ER) and internal rotation (IR) were applied at 0°, 30°, 60° and 90° of flexion under constant 200 N axial loading. All of the parameters were initially tested in the intact and ACL-deficient states, followed by two different types of posterolateral impression fractures. The dislocation height was 10 mm, and the width was 15 mm in both groups. The intraarticular depth of the fracture corresponded to half of the width of the posterior horn of the lateral meniscus in the first group (Bankart 1) and 100% of the meniscus width in the second group (Bankart 2).

RESULTS

There was a significant decrease in knee stability after both types of posterolateral tibial plateau fractures in the ACL-deficient specimens, with increased anterior translation in the simulated Lachman test at 0° and 30° of knee flexion (p = 0.012). The same effect was seen with regard to the simulated pivot-shift test and IR of the tibia (p = 0.0002). In the ER and posterior drawer tests, ACL deficiency and concomitant fractures did not influence knee kinematics (n.s.).

CONCLUSION

This study demonstrates that high-grade impression fractures of the posterolateral aspect of the tibial plateau increase the instability of ACL-deficient knees and result in an increase in translational and anterolateral rotational instability.

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.

Classification of Bone Bruises in Pediatric Patients With Anterior Cruciate Ligament Injuries

Background

Bone bruises are frequently found on magnetic resonance imaging (MRI) after an anterior cruciate ligament (ACL) tear in pediatric patients.

Purpose

To establish a classification system for different bone bruise patterns to estimate the severity of a knee injury in pediatric patients with ACL tears.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

A medical database was retrospectively reviewed to identify all cases of primary ACL tears in patients who were aged ≤17 years at the time of the injury and underwent MRI at our institution within 4 weeks of the injury between January 2011 and December 2020. A total of 188 patients were identified (67 male, 121 female; mean age, 15.1 ± 1.4 years). Bone bruises were classified according to their depth and location on MRI in the sagittal and coronal planes.

Results

The new classification system identified 3 grades of depth: grade I, the bone bruise was located within the epiphysis but did not reach the epiphyseal plate (n = 54 [35.3%]); grade II, the bone bruise was within the epiphysis that reached the epiphyseal plate (n = 55 [35.9%]); and grade III, the bone bruise was in both the epiphysis and metaphysis (n = 44 [28.8%]). The bone bruise location was classified into 4 types: type a, the deepest bone bruise area was in the lateral tibial plateau (n = 66 [43.1%]); type b, the deepest bone bruise area was in the lateral femoral condyle, commonly occurring in the lateral one-third to two-thirds of the lateral femoral condyle (n = 22 [14.4%]); type c, the bone bruise area had a similar depth in both the lateral femoral condyle and lateral tibial plateau (n = 54 [35.3%]); and type d, the bone bruise area was in the lateral tibial plateau and lateral femoral condyle and extended to the fibular head (n = 11 [7.2%]). The prevalence of collateral ligament injuries increased from grade I to III. All patients with grade III type c bone bruises had meniscal lesions.

Conclusion

This new classification system provides a basis for estimating associated lesions of the knee before surgery.

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 Association Between Bone Bruises and Concomitant Ligaments Injuries in Anterior Cruciate Ligament Injuries: A Systematic Review and Meta-analysis

Background

Bone bruises and concomitant ligament injuries after anterior cruciate ligament (ACL) injuries have attracted attention, but their correlation and potential clinical significance remain unclear.

Purpose

To assess the relationship between bone bruises and concomitant ligamentous injuries in ACL injuries.

Study design

Systematic review.

Methods

A comprehensive search of PubMed, Embase, Web of Science, and Cochrane Library was completed from inception to October 20, 2021. All articles that evaluated the relationship between bone bruises and related ligaments injuries were included. Methodological Index for Non-Randomized Studies (MINORS) was used for quality assessment as well as Review Manager 5.3 was used for data analysis.

Results

A total of 19 studies evaluating 3292 patients were included. After meta-analysis, anterolateral ligament (ALL) injuries were associated with bone bruising on the lateral tibial plateau (LTP) (RR = 2.33; 95% CI 1.44-3.77; p = 0.0006), lateral femoral condyle (LFC) (RR = 1.97; 95% CI 1.37-2.85; p = 0.0003) and medial tibial plateau (MTP) (RR = 1.62; 95% CI 1.24-2.11; p = 0.0004); Moreover, medial collateral ligament (MCL) injuries were associated with bone bruising on the femur (RR = 1.49; 95% CI 1.17-1.90; p = 0.001), and no statistical significance was found between bone bruising on the MTP and Kaplan fiber (KF) injuries (RR = 1.58; 95% CI 1.00-2.49; p = 0.05). Nonetheless, the current evidence did not conclude that bone bruises were associated with lateral collateral ligament (LCL) injuries.

Conclusion

For individuals with an ACL injury, bone bruises of the LTP, LFC, and MTP can assist in the diagnosis of ALL injuries. Furthermore, femoral bruising has potential diagnostic value for MCL injuries. Knowing these associations allows surgeons to be alert to ACL-related ligament injuries on MRI and during operations in future clinical practice.

The Incidence of Posterolateral Tibial Plateau and Central Lateral Femoral Condylar Impaction Fractures in a Pediatric and Young Adult Population

BACKGROUND

Posterolateral tibial plateau and central lateral femoral condylar impaction fractures are known to occur in the setting of anterior cruciate ligament (ACL) tears. There have been no prior investigations into the incidence and morphology of posterolateral tibial plateau impaction fractures in the setting of ACL injury in a pediatric population.

METHODS

Patients between 9 and 22 years of age with knee magnetic resonance imagings (MRIs) performed demonstrating complete or partial ACL tear were included in this study. MRI reports were reviewed to denote the presence of posterior cruciate ligament, medial collateral ligament, or lateral collateral ligament injury, meniscus tears, cartilage lesions. MRIs were reviewed by 2 fellowship-trained orthopaedic surgeons to denote the presence of posterolateral tibial plateau and central lateral femoral condylar impaction fractures and physeal status of femoral and tibial physes. Statistical analysis performed included χ 2 analysis and the Student t testing.

RESULTS

A total of 328 patients with a primary ACL tear were identified. The mean age of patients included was 16.5 years (range: 9.0-21.5). The incidence of posterolateral tibial plateau impaction fractures was 83/328 (25.3%) while the incidence of lateral femoral condylar impaction fractures was 119/328 (36.3%). Bipolar impaction fractures occurred in 37/328 (11.3%). Of the 83 tibial impaction fractures identified, 82 were low-grade morphologic subtypes. Patients with lateral tibial plateau impaction fractures were older than those with no fracture (17.2±2.2 vs. 16.3±2.1, P =0.001). Only 3/38 (7.9%) patients with an open tibial physis sustained a tibial plateau impaction fracture compared with 80/290 (27.6%) with a closed tibial physis (χ 2 value: 6.9, P =0.009). There was no difference in proportion of patients with lateral femoral condylar impaction fractures based on femoral physeal status ( P =0.484).

CONCLUSION

The incidence of posterolateral tibial plateau impaction fractures in the setting of ACL tear in a pediatric and young adult patient population appears to be lower while lateral femoral condylar impaction fractures occur more frequently when comparing to previously reported incidences found in adult populations in the literature. Furthermore, posterolateral tibial plateau impaction fractures occur less frequently in those with an open proximal tibial physis and high-grade posterolateral tibial plateau bone loss is exceedingly rare in pediatric and young adult patients. Lateral femoral condylar impaction fractures are associated with lateral meniscal tears and medial meniscal ramp lesions.

LEVEL OF EVIDENCE

Level IV-cross-sectional study.

Tibial slope in the posterolateral quadrant with and without ACL injury

INTRODUCTION

An increased tibial slope is a risk factor for rupture of the anterior cruciate ligament. In addition, a tibial bone bruise or posterior lateral impression associated with slope changes also poses chronic ligamentous instability of the knee joint associated with an anterior cruciate ligament (ACL) injury. In the majority of cases, the slope is measured in one plane X-ray in the lateral view. However, this does not sufficient represent the complex anatomy of the tibial plateau and especially for the posterolateral quadrant. Normal values from a "healthy" population are necessary to understand if stability of the knee joint is negatively affected by an increasing slope in the posterolateral area. Until now there are no data about the physiological slope in the posterolateral quadrant of the tibial plateau.

MATERIALS AND METHODS

In 116 MRI scans of patients without ligamentous lesions and 116 MRI scans with an ACL rupture, tibial slope was retrospectively determined using the method described by Hudek et al. Measurements were made in the postero-latero-lateral (PLL) and postero-latero-central (PLC) segments using the 10-segment classification. In both segments, the osseous as well as the cartilaginous slope was measured. Measurements were performed by two independent surgeons.

RESULTS

In the group without ligamentous injury the mean bony PLL slope was 5.8° ± 4.8° and the cartilaginous PLL slope was 6.7° ± 4.8°. In the PLC segment the mean bony slope was 6.6° ± 5.0° and the cartilaginous slope was 9.4° ± 5.7°. In the cohort with ACL rupture, the bony and cartilaginous slope in both PLL and PCL were significantly higher (P < 0.001) than in the group without ACL injury (bony PLL 9.8° ± 4.8°, cartilage PLL 10.4° ± 4.7°, bony PLC 10.3° ± 4.8°, cartilage PLL 12.8° ± 4.3°). Measurements were performed independently by two experienced surgeons. There were good inter- (CI 87-98.7%) and good intraobserver (CI 85.8-99.6%) reliability.

CONCLUSION

The bony and the cartilaginous slope in the posterolateral quadrant of the tibial plateau are different but not independent. Patients with an anterior cruciate ligament injury have a significantly steeper slope in the posterolateral quadrant compared to a healthy group. Our data indicate that this anatomic feature might be a risk factor for a primary ACL injury which has not been described yet.

LEVEL OF EVIDENCE

III.

Age, male sex, higher posterior tibial slope, deep sulcus sign, bone bruises on the lateral femoral condyle, and concomitant medial meniscal tears are risk factors for lateral meniscal posterior root tears: a systematic review and meta-analysis

PURPOSE

Lateral meniscus posterior root tears (LMPRTs) are commonly found in patients with anterior cruciate ligament (ACL) injuries. However, risk factors for LMPRTs are not well known. This study was designed to systematically review the available evidence regarding risk factors associated with LMPRTs.

METHODS

The PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched for papers containing the key words "lateral meniscus posterior root tears", "LMPRTs" and "risk factor". Inclusion screening, data extraction, and quality assessment of the included articles were conducted independently by two authors. Statistical analysis was conducted to determine risk factors for LMPRTs.

RESULT

Seventeen studies with a total sample size of 6, 589 patients were identified. The pooled prevalence of LMPRTs was 9.6% (range, 5.1-33.8%) for ACL injury. Significant risk factors included a patient age of < 30 [OR = 1.4, 95% CI (1.07, 1.84), p = 0.01], male sex [OR = 1.50, 95% CI (1.24,1.81), p = 0.01], higher body mass index (BMI) [MD = 0.45, 95% CI (0.13, 0.76), p < 0.01], higher lateral posterior tibial slope (LPTS) [MD = 2.22, 95% CI (1.37, 3.07), p < 0.01], deep sulcus sign [OR = 5.76, 95% CI (1.35, 24.52), p < 0.01] and bone bruises on lateral femoral condyle [OR = 4.88, 95% CI (1.27, 18.77), p < 0.01], lateral meniscal extrusion > 1 mm [OR = 5.56, 95% CI (1.52, 20.29), p < 0.01] and > 3 mm [OR = 12.91 95% CI (1.28, 130.01), p < 0.01], medial meniscal tears [OR = 1.40, 95% CI (1.12, 1.75), p < 0.01], and medial ramp lesions [OR = 2.29, 95% CI (1.35, 3.89), p < 0.01].

CONCLUSION

Age below 30, male, higher BMI, higher LPTS, deep sulcus sign, bone bruises on lateral femoral condyle, lateral meniscal extrusion, medial meniscal tear, and medial ramp lesion are risk factors for LMPRTs.

LEVEL OF EVIDENCE

Level IV.

Medial meniscus tears are most prevalent in type I ACL tears, while type I ACL tears only account for 8% of all ACL tears

PURPOSE

This study aimed to assess the distribution of different anterior cruciate ligament (ACL) tear locations in different magnetic resonance imaging (MRI) planes, and to explore the relationships of ACL tear types with both meniscus injuries and bone bruising.

METHODS

A retrospective study was performed in patients under 60 years old who underwent MRI scans in the sagittal and coronal oblique planes of the knee for ACL tears between 2014 and 2020. Patients with reports of chronic tears, partial tears, or prior surgeries were excluded. Tear locations were classified into five types, and the meniscus tear measurement variables included the presence of ramp, root, bucket-handle, and other types of tears. All injuries were confirmed by arthroscopy. Meanwhile, the presence and location of bone bruising were analysed and scored with the Whole-Organ Magnetic Resonance Imaging Score (WORMS) bone bruising subscale.

RESULTS

A total of 291 patients were included. The prevalence rates of type I and type III injuries were 23/291 (7.9%) and 145/291 (49.8%) in the sagittal plane and 22/291 (7.6%) and 179/291 (61.5%) in the oblique coronal plane, respectively. The prevalence of medial meniscus tears with ACL tears was 126/291 (43.3%), while that of lateral meniscus tears with ACL tears was 77/291 (26.5%). The highest prevalence of medial meniscus injury with ACL tears was 15/22 (68.2%) for type I injuries. Bone bruises were located on the lateral femoral center in 125 patients (46%) and on the lateral tibia posterior in 132 patients (48%); the common areas of bone bruising were slightly correlated with type III ACL tears but not correlated with type I ACL tears.

CONCLUSION

The plane in which an MRI scan is performed affects the classification of ACL tears. The tear type is associated with the prevalence of medial meniscus injuries, and medial meniscus tears are most prevalent in type I ACL tears.

LEVEL OF EVIDENCE

IV.

Revisiting the management of tibial plateau fractures

Three-dimensional imaging has changed the understanding and management of tibial plateau fractures. In the 1970s, Schatzker proposed a classification for tibial plateau fractures, which highlighted the morphology of the six principal types. More recently, this original classification was complimented by an extended one underscoring the importance of understanding where the split wedge fragment(s) is/are located in three dimensions. The extended classification introduced the split wedge fragment and the continuity of the rim as the determinants of joint stability and the critical role that this plays in the management of tibial plateau fractures. The current manuscript re-emphasizes contemporary concepts of tibial plateau stability and depicts key issues which must be considered when planning the definitive surgical fixation of tibial plateau fractures.

Effect Comparison of Assisted Surgery Simulated by Preoperative 3D Reconstruction and Minimally Invasive Surgery with the Assist of Knee Arthroscopy in the Treatment of Tibial Plateau Fracture under the Background of Intelligent Medicine

Objective

To explore the effect comparison of the assisted surgery simulated by preoperative 3D reconstruction and the minimally invasive surgery with the assist of knee arthroscopy in the treatment of tibial plateau fracture (TPF) under the background of intelligent medicine.

Methods

100 patients with TPF admitted to our hospital from January 2021 to January 2022 were selected as the study subjects. According to the order of admission, the patients were divided into the simulation group with 3D reconstruction (n = 50) and the auxiliary group with knee arthroscopy (n = 50), and the clinical indicators were compared between the two groups.

Results

There was no significant difference in any other clinical treatment indexes between the two groups except the surgery time (P > 0.05), and there was no significant difference in knee flexion ability, walking ability, and Rasmussen scores between the two groups after treatment (P > 0.05). However, compared with the auxiliary group with knee arthroscopy, the mean posterior slope angle and varus angle of the patients were significantly higher (P < 0.001), and the total incidence of complications was significantly lower (P < 0.05).

Conclusion

Based on the analysis under the background of intelligent medicine, it is found that the assisted surgery simulated by preoperative 3D reconstruction has a better effect and a higher safety, but they have the similar effects on improving the knee joint function of patients.

Mechanism of non-contact ACL injury: OREF Clinical Research Award 2021

Anterior cruciate ligament (ACL) ruptures significantly impact athletes in terms of return to play and loss of long-term quality of life. Before the onset of this study, understanding the mechanism of ACL injury was limited. Thus, the primary focus of this manuscript is to describe our multi-faceted approach to uncovering the mechanism of noncontact ACL injury (NC-ACLI) with the goal of developing preventive strategies. The initial qualitative analysis of ACL injury events revealed most (70%) injuries involve minimal to no contact and occurr during landing or deceleration maneuvers in team sports with a minor perturbation before the injury that may disrupt the neuromuscular system leading to poor body dynamics. A series of quantitative videotape studies demonstrated differences in leg and trunk positions at the time of NC-ACLI in comparison to control subjects. Analysis of the faulty dynamics provoking NC-ACLI, especially the flat-footed landing component, supports the theory that an axial compressive force is the critical factor responsible for NC-ACLI. Our magnetic resonance imaging study demonstrated the NC-ACLI position was associated with a higher tibial slope, and joint contact occurring on the flat, anterior portion of the lateral femoral condyle versus the round, posterior aspect. Both anatomic conditions favor sliding (pivot shift) over rolling in the presence of an axial compressive force. Subsequent cadaveric studies supported axial compressive forces as the primary component of NC-ACLI. Both a strong eccentric quadriceps contraction and knee abduction moments may increase the compressive force at the joint thereby lowering the axial threshold to injury. This manuscript summarizes the NC-ACLI mechanism portion of the 2021 OREF Clinical Research Award.

Magnetic resonance imaging (MRI) and Computed topography (CT) analysis of Schatzker type IV tibial plateau fracture revealed possible mechanisms of injury beyond varus deforming force

BACKGROUND

Schatzker type IV tibial plateau fractures (type IV TPFs) are known for complex fracture morphology and high frequency of knee subluxation. Varus deforming force has been believed to be the cause but which fails to explain the lateral tibial plateau comminution and the lateral femoral condyle bone edema observed on injury MRI. The purpose of this study is to further explore the mechanisms of injury of type IV TPFs by synthetically analysing the information obtained from MRI and CT of a cohort of patients.

METHODS

Between 2010 and 2019, 49 type IV TPFs were surgically treated in our hospital. The patients with complete preoperative CT and MRI were enrolled. They were classified according to OTA/AO and Luo's updated three-column classification (uTCC) after fracture morphology analysing and measuring. Then the injuries of cruciate/collateral ligaments and bone contusion were studied on MRI. The discrepancy between obvious fracture and occult bone contusion/soft tissue disruption among the groups of uTCC were compared and analysed.

RESULTS

Thirty patients were eligible for this study. Under uTCC system, all the cases were caused by varus force according to the tibial plateau angle and were classified into three groups of uTCC referring the posterior tibial slope angle: 4 were into hyperextension-varus, 21 into the extension-varus and 5 into the flexion-varus group. Fracture morphology analysis found in the extension-varus group, there were two distinct subgroups: OTA/AO 41B1.2 (medial+posteromedial columns disruption) and 41B3.3f (41B1.2 +posterolateral column disruption). Injury MRI revealed 28 of the 30 cases had more than 2 ligamentous injuries. The incidences of anterior and posterior cruciate injury were 96.7% and 43.3% respectively while 70% for medial collateral ligament (MCL). Eighteen out of 30 demonstrated apparent lateral femoral condyle bone contusion sign. Chi-square analysis found in the extension-varus group, the posterolateral column comminution was closely associated with lateral femoral condylar contusion (p<0.05) and MCL injuries (p<0.05). This finding and the absence of medial femoral condylar contusion was unlikely caused by uTCC proposed varus deforming force.

CONCLUSION

In contrast to varus impaction, some type IV TPFs was probably caused by valgus or rotation force.

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.

Risk Factors for Ramp Lesions of the Medial Meniscus: A Systematic Review and Meta-analysis

BACKGROUND

Failure to appropriately identify and repair medial meniscal ramp lesions at the time of anterior cruciate ligament (ACL) reconstruction (ACLR) may result in increased anterior tibial translation and internal rotation, increasing the risk for graft failure. Knowledge of the risk factors leading to the development of ramp lesions may enhance clinicians' vigilance in specific ACL-deficient populations and subsequently repair of these lesions at the time of ACLR.

PURPOSE

To perform a systematic review and meta-analysis of factors tested for associations with ramp lesions and to determine which were significantly associated with the presence of ramp lesions.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

PubMed, OVID/Medline, and Cochrane databases were queried in April 2020. Data pertaining to study characteristics and reported risk factors for ramp lesions were recorded. DerSimonian-Laird binary random-effects models were constructed to quantitatively evaluate the association between risk factors and ramp lesions by generating effect estimates in the form of odds ratios (ORs) with 95% CIs. Qualitative analysis was performed to describe risk factors that were variably reported.

RESULTS

The review included 12 studies with 8410 patients. The overall pooled prevalence of ramp lesions was 21.9% (range, 9.0%-41.7%). A total of 45 risk factors were identified, of which 8 were explored quantitatively. There was strong evidence to support that posteromedial tibial edema on magnetic resonance imaging (MRI) (OR, 2.12; 95% CI, 1.27-3.56; P = .004), age <30 years (OR, 2.02; 95% CI, 1.23-3.22; P = .002), and complete ACL tears (OR, 3.0; 95% CI, 1.41-6.20; P = .004) were risk factors for ramp lesions. There was moderate evidence to support that male sex (OR, 1.58; 95% CI, 1.36-1.83; P < .001) and concomitant lateral meniscal tears (OR, 1.54; 95% CI, 1.11-2.13; P = .009) were risk factors for ramp lesions. Chronic ACL injury (≥24 months) demonstrated minimal evidence as a risk factor (OR, 1.41; 95% CI, 1.14-1.74; P = .001). No significant associations were determined between contact injury or revision ACLR and the presence of ramp lesions.

CONCLUSION

Significant associations between male sex, age <30 years, posteromedial tibial edema on MRI, concomitant lateral meniscal tears, complete ACL tears, injury chronicity, and the presence of ramp lesions were found. Contact injury and revision ACLR were not significantly associated with the presence of ramp lesions.

A New Three-Dimensional Classification of Proximal Tibiofibular Fractures: A Multicenter Study

Objectives

To propose an updated definition of proximal tibia and fibula fracture (PTFF) and establish a three‐dimensional (3D) structure‐based classification of PTFF.

Methods

In total, 1358 adult patients (837 males and 521 females; 43.61 ± 15.13 years， 1364 affected knees) who were diagnosed with PTFF at the departments of orthopaedic surgery of four hospitals from January 2010 to December 2019 were enrolled. The new classification of PTFF, termed Wu classification, included three parts: classification of columns in the horizontal plane, regions in the frontal plane, and segments in the sagittal plane. All PTFFs were classified according to Schatzker, Luo, and Wu classification systems. Additionally, the incidence and characteristics of PTFFs were analyzed.

Results

The major internal structural fractures of PTFF were tibial plateau fracture (TPF) only (725, 53.15%), TPF and proximal fibular fracture (274, 20.09%), and isolated avulsion fracture of the posterior cruciate ligament (PCL) (189, 13.86%). Approximately a quarter of PTFF cases could not be classified using Schatzker or Luo classifications, but all PTFF cases could be classified using Wu classification. The most frequent PTFFs included all four columns in region IV, segment 2 (235, 17.23%); the posterolateral and posteromedial columns in region II, segment 2 (191, 14.00%); and the lateral and posterolateral columns in region IV, segment 2 (136, 9.97%). Isolated avulsion fracture of the anterior cruciate ligament (ACL) was categorized as three injury types, most of which involved the lateral and medial columns in region II, segment 1 (40/63, 64%). More than 97% of cases of isolated fractures of the PCL involved the posterolateral and posteromedial columns in region II, segment 2. The most frequent combined avulsion fracture of the ACL and PCL included all four columns in region II, segment 2 (18/24, 75%). All of the isolated avulsion fractures of the ACL were located in segment 1, and all those of the PCL in segment 2. The most common type of isolated proximal fibular fracture involved the posterolateral column in region III, segment 2 (23/26, 88%). The most frequent combined TPF and proximal fibular fracture involved all four columns in region IV, segment 2 (107/274, 39.05%).

Conclusions

All cases of PTFF could be classified by the new 3D Wu classification which should be beneficial for clinical diagnosis, guidance of treatment, statistical analysis, academic communication, and prognosis, and the most frequent PTFF involved all four columns in region IV, segment 2.

Clinical Implications of Bone Bruise Patterns Accompanying Anterior Cruciate Ligament Tears

BACKGROUND

Anterior cruciate ligament (ACL) tears are common injuries; they are often associated with concomitant injuries to other structures in the knee, including bone bruises. While there is limited evidence that bone bruises are associated with slightly worse clinical outcomes, the implications of bone bruises for the articular cartilage and the risk of developing osteoarthritis (OA) in the knee are less clear. Recent studies suggest that the bone bruise pattern may be helpful in predicting the presence of meniscal ramp lesions.

EVIDENCE ACQUISITION

A literature review was performed in EMBASE using the keyword search phrase (acl OR (anterior AND cruciate AND ligament)) AND ((bone AND bruise) OR (bone AND contusion) OR (bone AND marrow AND edema) OR (bone AND marrow AND lesion) OR (subchondral AND edema)).

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

The literature search returned 93 articles of which 25 were ultimately included in this review. Most studies identified a high prevalence of bone bruises in the setting of acute ACL injury. Individual studies have found relationships between bone bruise volume and functional outcomes; however, these results were not supported by systematic review. Similarly, the literature has contradictory findings on the relationship between bone bruises and the progression of OA after ACL reconstruction. Investigations into concomitant injury found anterolateral ligament and meniscal ramp lesions to be associated with bone bruise presence on magnetic resonance imaging.

CONCLUSION

Despite the ample literature identifying the prevalence of bone bruises in association with ACL injury, there is little evidence to correlate bone bruises to functional outcomes or progression of OA. Bone bruises may best be used as a marker for concomitant injury such as medial meniscal ramp lesions that are not always well visualized on magnetic resonance imaging. Further research is required to establish the longitudinal effects of bone bruises on ACL tear recovery.

STRENGTH OF RECOMMENDATION TAXONOMY

2.

Clinical Anatomy of the Anterior Meniscofemoral Ligament of Humphrey: An Original MRI Study, Meta-analysis, and Systematic Review

Background:

The anterior meniscofemoral ligament (aMFL) of Humphrey is an anatomically variable fibrous band of connective tissue that attaches between the lateral aspect of the medial femoral condyle and posterior horn of the lateral meniscus, running posterior to the anterior cruciate ligament and anterior to the posterior cruciate ligament (PCL). The presence of an intact aMFL may contribute to stabilization of the lateral compartment of the knee joint.

Purpose:

The original magnetic resonance imaging (MRI) arm of this study aimed to assess the aMFL incidence among Polish patients. The goal of the systematic review and meta-analysis was to review the literature discussing the clinical anatomy of the aMFL and provide data on its prevalence. It was hypothesized that significant heterogeneity exists within the published literature.

Study Design:

Cross-sectional study and systematic review; Level of evidence, 3.

Methods:

A retrospective investigation was performed on the MRI scans of 100 knees (52 right, 48 left) of Polish patients. Scans were randomly selected from a database of MRI examinations performed in 2019. For the meta-analysis, major online databases were queried for data on the aMFL, and 2 authors independently assessed and extracted data from all included studies. A quality assessment of the included articles was performed using the Anatomical Quality Assessment tool.

Results:

In the MRI arm of this study, the aMFL was found in 62 of the 100 lower limbs. The meta-analysis included 41 studies with a total of 4220 limbs. The aMFL was present in 55.5% (95% CI, 45.5%-65.3%) of cases. Arthroscopic studies yielded the highest prevalence (82.3% [95% CI, 36.6%-100.0%]); of MRI studies, the highest prevalence was at 3.0-T strength (51.0% [95% CI, 13.3%-88.2%]).

Conclusion:

Significant variability in the prevalence of the aMFL was found in the literature. More emphasis should be placed on the clinical relevance of injuries to the aMFL because of its significant role in the function of the knee. It is important to be aware that, because of the anatomy of the aMFL, the ligament can also function to support a torn PCL.

Clinical Anatomy of the Posterior Meniscofemoral Ligament of Wrisberg: An Original MRI Study, Meta-analysis, and Systematic Review

Background

The posterior meniscofemoral ligament (pMFL) of Wrisberg attaches to the posterior horn of the lateral meniscus and the lateral intercondylar aspect of the medial femoral condyle and passes posteriorly to the posterior cruciate ligament (PCL). The pMFL plays a role in recovery after PCL injuries and offers stability to the lateral meniscus, promoting normal knee function.

Purpose/Hypothesis

The aim of the magnetic resonance imaging (MRI) arm of this study was to evaluate the prevalence of the pMFL in Polish patients. The purpose of the systematic review and meta-analysis was to evaluate the clinical relevance of the pMFL in knee surgery. It was hypothesized that extensive variability exists in reports on the prevalence, function, and clinical significance of the pMFL.

Study Design

Cross-sectional study and systematic review; Level of evidence, 3.

Methods

A retrospective MRI investigation was conducted on 100 randomly selected lower limbs of Polish patients (56 male, 44 female) performed in 2019 to determine the prevalence of the pMFL. Additionally, an extensive literature search of major online databases was performed to evaluate all reported data on the pMFL. Assessments of article eligibility and data extraction were completed independently by 2 reviewers, and all disagreements were resolved via a consensus. A quality assessment of the included articles was performed using the Anatomical Quality Assessment tool.

Results

In the MRI arm of this study, the pMFL was observed in 73 of the 100 limbs. In the meta-analysis, 47 studies were included, totaling 4940 lower limbs. The pooled prevalence of the pMFL was found to be 70.4% (95% CI, 63.4%-76.9%); the mean length was 27.7 mm (95% CI, 24.8-30.5 mm) and the mean widths were 4.5, 6.1, and 4.1 mm for the meniscal and femoral attachments and midportion, respectively. The mean pMFL thickness was 2.3 mm (95% CI, 1.8-2.7 mm).

Conclusion

Despite the variability in the literature, the pMFL was found to be a prevalent and large anatomic structure in the knee joint. The shared features of this ligament with the PCL necessitate the consideration of its value in planning and performing arthroscopic procedures of the knee.

High-Grade Posterolateral Tibial Plateau Impaction Fractures in the Setting of a Primary Anterior Cruciate Ligament Tear Are Correlated With an Increased Preoperative Pivot Shift and Inferior Postoperative Outcomes After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Impaction fractures of the posterolateral tibial plateau have been previously described to occur in association with anterior cruciate ligament (ACL) tears; however, the effect of these injuries on patient-reported outcomes (PROs) after ACL reconstruction (ACLR) is not well known.

PURPOSE

(1) To assess the effect of posterolateral tibial plateau impaction fractures on preoperative clinical knee stability assessed by the Lachman and pivot-shift examinations and (2) to assess the effect of impaction fractures on PROs after ACLR.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients undergoing ACLR for primary ACL tears with available magnetic resonance imaging (MRI) scans were included in this study. MRI scans were reviewed for the presence of posterolateral tibial plateau impaction fractures, which were classified according to the morphological variant. Associations with clinical laxity determined by an examination under anesthesia were assessed using binary logistic regression. Also, 2-year postoperative PROs (12-Item Short Form Health Survey [SF-12] Mental Component Scale and Physical Component Scale [PCS], Lysholm, Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], and Tegner scores) were modeled using multiple ordinal logistic regression to assess the effect of posterolateral tibial plateau impaction fracture classification while adjusting for other covariates. Pearson correlation coefficients (PCCs) were used to assess for correlations between postoperative PROs and the amount of tibial plateau bone loss present.

RESULTS

Displaced posterolateral tibial plateau impaction fractures were present in 407 (49.3%) of 825 total knees included in this study. Knees with type IIIB impaction fractures had an increased likelihood of having a high-grade pivot shift (odds ratio, 2.3; P = .047), with no other impaction fracture types showing a significant association. There were no significant associations between posterolateral tibial plateau impaction fracture type and a higher Lachman grade. Of the 599 eligible knees with 2-year follow-up, postoperative information was obtained for 419 (70.0%). Patients improved in all PROs at a mean of 3.0 years after ACLR (P < .001). Multiple ordinal logistic regression demonstrated a posterolateral tibial plateau impaction fracture as an independent predictor of the postoperative Lysholm score, with higher grade impaction fractures showing decreased Lysholm scores. Pearson correlation testing demonstrated weak but statistically significant correlations between sagittal bone loss of posterolateral tibial plateau impaction fractures and SF-12 PCS (PCC = -0.156; P = .023), WOMAC total (PCC = 0.159; P = .02), Lysholm (PCC = -0.203; P = .003), and Tegner scores (PCC = -0.151; P = .032).

CONCLUSION

When classified into distinct morphological subtypes, high-grade posterolateral tibial plateau impaction fractures were independently associated with decreased postoperative outcomes after ACLR when controlling for other demographic or clinical variables. Patients with large depression-type posterolateral tibial plateau impaction fractures (type IIIB) had an increased likelihood of having high-grade pivot-shift laxity on clinical examination under anesthesia.