Risk Factors for Concomitant Collateral Ligament Injuries in Children and Adolescents With Anterior Cruciate Ligament Tears

Viability of shear wave elastography to predict mechanical/ultimate failure in the anterolateral and medial collateral ligaments of the knee

The purpose of this study was (1) to determine the utility of shear wave elastography as a predictor for the mechanical failure of superficial knee ligaments and (2) to determine the viability of shear wave elastography to assess injury risk potential. Our hypothesis was that shear wave elastography measurements of the anterolateral ligament and medial collateral ligament would directly correlate with the material properties and the mechanical failure of the ligament, serving as a prognostic measurement for injury risk. 8 cadaveric specimens were acquired, and tissue stiffness for the anterolateral ligament and medial collateral ligament were evaluated with shear wave elastography. The anterolateral ligament and medial collateral ligament were dissected and isolated for unilateral mechanical failure testing. Ultimate failure testing was performed at 100 % strain per second after 50 cycles of 3 % strain viscoelastic conditioning. Each specimen was assessed for load, displacement, and surface strain throughout failure testing. Rate of force, rate of strain development, and Young's modulus were calculated from these variables. Shear wave elastography stiffness for the anterolateral ligament correlated with mean longitudinal anterolateral ligament strain at failure (R2 = 0.853; P<0.05). Medial collateral ligament shear wave elastography calculated modulus was significantly greater than the anterolateral ligament shear wave elastography calculated modulus. Shear wave elastography currently offers limited reliability in the prediction of mechanical performance of superficial knee ligaments. The utility of shear wave elastography assessment for injury risk potential remains undetermined.

Comprehensive Clinical Examination of ACL Injuries

A comprehensive clinical examination of the potentially anterior cruciate ligament (ACL)-deficient knee should proceed as follows: inspection; palpation; range of motion; varus and valgus stress; neurovascular status; and finally provocative maneuvers. The Lachman, anterior drawer, Lever, and pivot shift tests are all greater than 90% specific for ACL pathology. Due to the relatively high coincidence of ACL injuries and those to the posterior cruciate ligament, posterolateral corner , posteromedial corner , and menisci, it is critical that the examiner perform provocative maneuvers to evaluate the integrity of these structures as well.

Prevalence and Predictors of Concomitant Meniscal and Ligamentous Injuries Associated With ACL Surgery: An Analysis of 20 Years of ACL Reconstruction at a Tertiary Care Children's Hospital

BACKGROUND

There is an increasing rate of procedures being performed for concomitant injuries during anterior cruciate ligament (ACL) surgery. Few studies have examined risk factors for these associated injuries in young patients.

HYPOTHESIS

There are patient-related factors predictive of concomitant knee pathology that differ between age-based cohorts.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Natural language processing was used to extract clinical variables from available notes of patients undergoing ACL surgery between 2000 and 2020 at a single institution (5174 ACL surgeries; mean age, 17 ± 4 years; 53.1% female; accuracy, >98%). Patients were stratified to pediatric (5-13 years), adolescent (14-19 years), and young adult (20-35 years) cohorts. Logistic regression was used to determine predictors of concomitant injury to the menisci, medial collateral ligament (MCL), posterolateral corner (PLC), and posterior cruciate ligament (PCL).

RESULTS

Between 2000 and 2020, 54% of pediatric, 71% of adolescent, and 70% of adult patients had ≥1 concomitant soft tissue injury. In children and adolescents, increased age was consistently predictive of sustaining a concomitant injury (P < .02). Female children had increased odds of concomitant medial meniscal injury, while female adults had decreased odds (P≤ .046). Adolescent and adult female patients had decreased odds of concomitant lateral meniscal injury (P≤ .027). Female children had increased odds of injury to the MCL (P = .015), whereas female children and adolescents had decreased odds of PCL injury (P≤ .044). Adolescents undergoing revision ACL surgery had increased odds of meniscal injury (P≤ .001) and decreased odds of concomitant MCL injury (P = .028). Increased body mass index (BMI) was associated with increased odds of concomitant medial meniscal injury in all cohorts (P≤ .041), lateral meniscal injury in adults (P = .045), and PLC injury in children (P = .016). Contact injuries were associated with increased odds of MCL injury in adolescents (P = .017) and PLC injury in adolescents and adults (P < .014).

CONCLUSION

These findings support the hypothesis, as there were multiple factors that significantly affected the risk of concomitant injuries that differed between cohorts. Increased age, BMI, and contact injury history were generally associated with increased odds of sustaining a concomitant injury, whereas female sex and revision ACL surgery had mixed effects. Further studies are essential to investigate the sex-based differences in risk for concomitant injuries and to develop tailored treatment plans that minimize the risk of secondary ACL injury.

Comparison of side-cutting maneuvers versus low impact baseball swing on knee ligament loading in adolescent populations

BACKGROUND

High impact sports are associated with an increased incidence rate for knee ligament injuries, specifically pertaining to the anterior cruciate ligament and medial collateral ligament. What is less clear is (i) the extent to which high impact activities preferentially load the anterior cruciate ligament versus the medial collateral ligament, and (ii) whether both ligaments experience similar stretch ratios during high loading scenarios. Therefore, the goal of this project was to assess how different loading conditions experienced through more at-risk sporting maneuvers influence the relative displacements of the anterior cruciate ligament and medial collateral ligament. The focus of the study was on adolescent patients - a group that has largely been overlooked when studying knee ligament biomechanics.

METHODS

Through kinetic knee data obtained through motion capture experimentation, two different loading conditions (high vs low impact) were applied to 22 specimen-specific adolescent finite element knee models to investigate the biomechanical impact various sporting maneuvers place on the knee ligaments.

FINDINGS

The high impact side cutting maneuver resulted in 102% and 47% increases in ligament displacement compared to the low impact baseball swing (p < 0.05) for both the anterior cruciate ligament and medial collateral ligament.

INTERPRETATION

Quantifying biomechanical risks that sporting activities place on adolescent subjects provides physicians with insight into knee ligament vulnerability. More specifically, knowing the risks that various sports place on ligaments helps guide the selection of sports for at-risk patients (especially those who have undergone knee ligament surgery).

Revision Anterior Cruciate Ligament, Lateral Collateral Ligament Reconstruction, and Osteochondral Allograft Transplantation for Complex Knee Instability

Anterior cruciate ligament (ACL) injuries rarely occur as an isolated event and often include associated meniscal, subchondral bone, and collateral ligament injuries. Concomitant pathology frequently complicates primary and revision ACL reconstruction and must be addressed to ensure comprehensive diagnosis and treatment. In this Technical Note, we describe our method for treatment of complex knee instability following multiple failed ACL reconstruction using a multiligament reconstruction technique with an osteochondral allograft transplantation to the lateral femoral condyle. This comprehensive repair technique restores the anatomic load bearing forces of the cruciate and collateral ligaments and promotes biological repair through incorporation of cartilage resurfacing to ultimately achieve optimal kinematics of the knee joint.

Reliability of MRI Detection of Kaplan Fiber Injury in Pediatric and Adolescent Patients with ACL Tears

Background:

While studies have described Kaplan fiber (KF) injury in up to 60% of adults with anterior cruciate ligament (ACL) tears, the incidence of KF injury in the pediatric and adolescent population remains unknown.

Purpose:

To (1) determine the reliability of using magnetic resonance imaging (MRI) to identify KF injury in the pediatric and adolescent population and (2) define the incidence of KF injury in these patients with acute ACL injuries.

Study Design:

Cohort study (diagnosis); Level of evidence, 3.

Methods:

The authors retrospectively identified patients ≤18 years of age who underwent ACL reconstruction for acute tears between 2013 and 2020. All preoperative MRI scans were reviewed independently and in a blinded fashion by 2 musculoskeletal radiologists, who noted the presence of the KF complex and any evidence of injury; interrater reliability was assessed. Patient characteristics, time from injury to MRI, laterality, and concomitant ligamentous or meniscal injuries were recorded, and associations between patient or injury characteristics and KF integrity on MRI were assessed.

Results:

In total, 51 patients (mean age, 14.9 years) met the inclusion criteria. Of these, 27 patients were female and 31 sustained an injury to the right knee. With respect to KF integrity, radiologist 1 visualized KF injury in 29% of patients, while radiologist 2 visualized KF injury in 35% of patients. In 12% of cases for radiologist 1 and 6% of cases for radiologist 2, KFs were unable to be visualized at all. The overall percentage agreement between the 2 radiologists was 76.5% with a kappa statistic of 0.57 (moderate agreement). There were no significant associations found between the presence of KF injury and patient age, sex, laterality, body mass index, concomitant ligamentous injury, or meniscal injury. However, visualization of KF injury on MRI was associated with a shorter time from index injury to MRI (15 days vs 23 days; P = .044).

Conclusion:

Approximately one-third of pediatric and adolescent patients who underwent ACL reconstruction were found to have KF injuries. Standard preoperative MRI scans can reliably be used to visualize KF injury in the majority of pediatric and adolescent patients with ACL tears, especially when the MRI is performed in the acute setting.

A case report of multi-ligaments injury of the ACL-MCL-PT combined with an occult fracture of the posterolateral tibial plateau

The anterior cruciate ligament and medial collateral ligament are important static stabilizers of the knee. The patellar tendon is part of the knee extensor mechanism. The injury simultaneously involving these three structures is very rare. This paper reports a case with simultaneous ipsilateral rupture of the anterior cruciate ligament, medial collateral ligament, patellar tendon, and an occult compression fracture of the posterolateral tibial plateau. This injury pattern has not been reported in literature yet. The injury mechanism was hypothesized as a sudden anterior translation and valgus of the proximal tibia when the knee was in high flexion, followed by an eccentric quadriceps' contracture. In the followed management, ruptured medial collateral ligament and patellar tendon were sutured with augment, while the torn anterior cruciate ligament and fracture were treated conservatively. The outcome of the treatment was satisfactory, and no complication was observed. To this combined injury, a comprehensive consideration, including physical examination, multiple imaging examinations, and analysis of injury mechanism, is essential for a full diagnosis and treatment decision. Especially, computed tomography may help to identify an occult or non-displaced fracture, which would be easily misdiagnosed when nothing unusual was found in routine X-rays. In the treatment, it is suggested to perform a selective or step-by-step repair to the damaged structures, rather than an immediate total repair after injury.

Incidence and Predictors of Subsequent Surgery After Anterior Cruciate Ligament Reconstruction: A 6-Year Follow-up Study

BACKGROUND

The cause of subsequent surgery after anterior cruciate ligament (ACL) reconstruction varies, but if risk factors for specific subsequent surgical procedures can be identified, we can better understand which patients are at greatest risk.

PURPOSE

To report the incidence and types of subsequent surgery that occurred in a cohort of patients 6 years after their index ACL reconstruction and to identify which variables were associated with the incidence of patients undergoing subsequent surgery after their index ACL reconstruction.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Patients completed a questionnaire before their index ACL surgery and were followed up at 2 and 6 years. Patients were contacted to determine whether any underwent additional surgery since baseline. Operative reports were obtained, and all surgical procedures were categorized and recorded. Logistic regression models were constructed to predict which patient demographic and surgical variables were associated with the incidence of undergoing subsequent surgery after their index ACL reconstruction.

RESULTS

The cohort consisted of 3276 patients (56.3% male) with a median age of 23 years. A 6-year follow-up was obtained on 91.5% (2999/3276) with regard to information on the incidence and frequency of subsequent surgery. Overall, 20.4% (612/2999) of the cohort was documented to have undergone at least 1 subsequent surgery on the ipsilateral knee 6 years after their index ACL reconstruction. The most common subsequent surgical procedures were related to the meniscus (11.9%), revision ACL reconstruction (7.5%), loss of motion (7.8%), and articular cartilage (6.7%). Significant risk factors for incurring subsequent meniscus-related surgery were having a medial meniscal repair at the time of index surgery, reconstruction with a hamstring autograft or allograft, higher baseline Marx activity level, younger age, and cessation of smoking. Significant predictors of undergoing subsequent surgery involving articular cartilage were higher body mass index, higher Marx activity level, reconstruction with a hamstring autograft or allograft, meniscal repair at the time of index surgery, or a grade 3/4 articular cartilage abnormality classified at the time of index ACL reconstruction. Risk factors for incurring subsequent surgery for loss of motion were younger age, female sex, low baseline Knee injury and Osteoarthritis Outcome Score symptom subscore, and reconstruction with a soft tissue allograft.

CONCLUSION

These findings can be used to identify patients who are at the greatest risk of incurring subsequent surgery after ACL reconstruction.