Magnetic resonance imaging does not reliably detect Kaplan fiber injury in the setting of anterior cruciate ligament tear

Abstract

Purpose There has been a continued efort to better understand the role Kaplan iber injury plays in persistent instability following ACL tears. However, the prevalence of these injuries remains poorly understood. Therefore, the purpose of this study was to deine the prevalence of Kaplan iber injury in the setting of complete anterior cruciate ligament tear using a commonly used grading system for assessing ligament injuries. The inter-rater reliability of this commonly used grading system and the relationship between Kaplan iber injury and injury to other structures commonly found in conjunction with ACL tears was also evaluated. Methods All isolated, complete anterior cruciate ligament tears conirmed on magnetic resonance imaging within 90 days of injury between 2014 and 2020 at a single institution were included for analysis. Each scan was read by two, fellowshiptrained musculoskeletal radiologists. Kaplan iber injury was evaluated using a previously described grading scheme. Kappa, , of inter-rater agreement was determined for all magnetic resonance image scans. Kruskal Wallis test was performed to assess for associations between Kaplan iber injury and magnet strength (1.5 T vs. 3.0 T), patient gender, the presence of medial and/or lateral meniscal tears, and/or posterolateral tibial bone bruise. Results Between 2014 and 2020, 131 patients (94 males, 37 females) with a complete anterior cruciate ligament tear were included in the inal analysis. The mean age of the cohort was 27.8 ± 6.8 years. Kaplan iber injuries were identiied in 51 of 131 (38.9%, CI 31.0-47.5%) scans with complete anterior cruciate ligament injuries (Grade 1: 28, Grade 2: 18, and Grade 3: 5). Inter-rater agreement for Kaplan iber injury was fair ( = 0.3) with 43 (32.8%) scans requiring third reviewer adjudication. There were no signiicant associations between Kaplan iber injury and gender, magnet strength, meniscal tears, or posterolateral tibial bone bruise. ConclusionThe prevalence of Kaplan iber injuries was comparable to previously described rates; however, the classiication system used to report Kaplan iber injury was associated with low inter-rater reliability. The presence of Kaplan iber injury was not associated with other injuries commonly observed in conjunction with ACL tear. The previously proposed Kaplan iber injury classiication system is not reproducible nor is it likely to aid surgeons in distinguishing higher grades of rotatory knee instability. Level of evidence Level IV.

Will the Kaplan Fiber Complex Be the ‘‘New Anterolateral Ligament’’? Insights from Direct Surgical Exploration in the Context of ACL Injury and Reconstruction

“…Several very recent papers tried to identify the incidence of Kaplan fiber injury in the context of ACL rupture. To this end, Berthold et al [ 7 ], through a well-performed Magnetic Resonance study with three independent reviewers, retrospectively identified a relevant number of patients with concomitant injury to the Kaplan fibers, confirming the results of similar studies [ 8 , 9 ]. Other authors have tried to correlate Kaplan fiber injury with laxity or concomitant injuries, with contrasting and inconclusive results [ 8 , 10 ].…”

MRI Does Not Reliably Detect Kaplan Fiber Injury In Skeletally Immature Patients with an Acute ACL Tear

“…The prevalence of KF injury in acute ACL tear among adults has been reported to be between 23% and 71% using various KF injury criteria. 4 , 5 , 17 , 18 , 22 The published criteria of Batty et al 4 reported an acute KF injury rate of 23.7%. The present study found a KF injury rate of 11.1% (95% CI, 1.9%-20.2%), which suggests that KF injury may be less common in the skeletally immature patient population or that the Batty et al 4 KF diagnostic criteria are less reliable in the pediatric population.…”

“…The 37.7% incidence of KF injury found among the present cohort using the Van Dyck et al 22 grading scheme is similar to previous studies looking at an adult population, with reported rates of 33% to 39%. 17 , 22 The observed difference in prevalence between the 2 injury criteria can be explained by the fact that isolated periligamentous edema is not considered a KF injury in the Batty scheme. In addition, the Batty group showed that the incidence of KF injury detected on MRI scans outside of the first 90 days from the date of injury was roughly a quarter of the initial rate at 6.4%.…”

“…There have been multiple studies using novel diagnostic criteria to define the prevalence of KF injury on magnetic resonance imaging (MRI) scans in the setting of acute ACL tears among skeletally mature patients, and reported rates have ranged from 23% to as high as 71% depending on the criteria. 4 , 17 , 18 , 22 To date, there has been no investigation to our knowledge into the incidence of KF injuries in skeletally immature patients with ACL tears nor has there been a study comparing KF injury rates and interrater reliabilities among the different diagnostic criteria.…”

Editorial Comment: Selected Proceedings From the Society of Military Orthopaedic Surgeons 2021 Annual Meeting

“…T he Society of Military Orthopaedic Surgeons, founded in 1958 on Governor's Island, NY, USA, has long focused on the musculoskeletal care of the combat-wounded warrior [11]. The unique demands of combat medicine have driven the need for ingenious solutions to difficult problems, including prolonged field care, airborne evacuation, and volumetric muscle loss with subsequent rehabilitation challenges in limb salvage [9,[15][16]. Upon its recognition and incorporation into the The 2021 SOMOS Annual Meeting was no exception, featuring the impressive efforts of the SOMOS membership to include our international colleagues.…”