Proximal adductor avulsions are rarely isolated but usually involve injury to the PLAC and pectineus: descriptive MRI findings in 145 athletes

Abstract

Purpose The purpose of the study is to review the MRI findings in a cohort of athletes who sustained acute traumatic avulsions of the adductor longus fibrocartilaginous entheses, and to investigate related injuries namely the pyramidalis–anterior pubic ligament–adductor longus complex (PLAC). Associated muscle and soft tissue injuries were also assessed. Methods The MRIs were reviewed for a partial or complete avulsion of the adductor longus fibrocartilage, as well as continuity or separation of the adductor longus from the pyramidalis. The presence of a concurrent partial pectineus tear was noted. Demographic data were analysed. Linear and logistic regression was used to examine associations between injuries. Results The mean age was 32.5 (SD 10.9). The pyramidalis was absent in 3 of 145 patients. 85 of 145 athletes were professional and 52 competed in the football Premier League. 132 had complete avulsions and 13 partial. The adductor longus was in continuity with pyramidalis in 55 athletes, partially separated in seven and completely in 81 athletes. 48 athletes with a PLAC injury had a partial pectineus avulsion. Six types of PLAC injuries patterns were identified. Associated rectus abdominis injuries were rare and only occurred in five patients (3.5%). Conclusion The proximal adductor longus forms part of the PLAC and is rarely an isolated injury. The term PLAC injury is more appropriate term. MRI imaging should assess all the anatomical components of the PLAC post-injury, allowing recognition of the different patterns of injury. Level of evidence Level III.

One-Year Clinical and Imaging Follow-up After Exercise-Based Treatment for Acute Complete Adductor Longus Tendon Avulsions in Athletes: A Prospective Case Series

“…Axial oblique fat-suppressed T2-weighted magnetic resonance imaging (MRI) scans of a 24-year-old male soccer player with a left adductor longus tendon avulsion injury. (A) MRI scan 1 day after injury shows a disruption between the left proximal adductor longus tendon (thick arrow) and the fibrocartilage of the pubic bone (star), also described as the “broken butterfly sign.” 14 (B) MRI scan 33 days after injury (at return-to-sport clearance) still shows clear disruption between the adductor longus and the pubic bone. The hypointense signal (arrowhead) between the pubic bone and adductor longus tendon suggests emerging fibrosis.…”

“…There has been a recent emphasis on the anatomic connection between the pyramidalis–anterior pubic ligament–adductor longus complex (PLAC) and its involvement in adductor longus avulsions. 13,14 Therefore, we scored the presence of a pyramidalis muscle injury, the appearance of discontinuity between the pyramidalis and the adductor longus, and anterior pubic ligament disruption. We also scored the “broken butterfly sign,” which is described as a disruption of a “wing” on axial oblique images, wherein the “wings of the butterfly” consist of the 2 proximal adductor longus tendons and FC and the 2 pubic bones, with the symphysis disc as the “body of the butterfly.” 14 The PLAC components are also used to classify avulsion injuries into 6 types 14 :…”

“…We also scored the ''broken butterfly sign,'' which is described as a disruption of a ''wing'' on axial oblique images, wherein the ''wings of the butterfly'' consist of the 2 proximal adductor longus tendons and FC and the 2 pubic bones, with the symphysis disc as the ''body of the butterfly.'' 14 The PLAC components are also used to classify avulsion injuries into 6 types 14 : Type 1: complete FC avulsion, pyramidalis separated from adductor longus, intact pectineus Type 2: complete FC avulsion, pyramidalis separated from adductor longus, partial pectineus tear Type 3: complete FC avulsion, pyramidalis connected to adductor longus, intact pectineus Type 4: complete FC avulsion, pyramidalis connected to adductor longus, partial pectineus tear Type 5: complete FC avulsion, pyramidalis partially separated from adductor longus, partial pectineus tear Type 6: partial FC avulsion, pyramidalis connected to adductor longus, intact pectineus…”

“…17 MRI is considered the gold standard for use in the diagnosis of avulsion injuries, and detailed MRI variations of avulsion injuries are reported to potentially influence treatment decisions. 14…”

“…17 MRI is considered the gold standard for use in the diagnosis of avulsion injuries, and detailed MRI variations of avulsion injuries are reported to potentially influence treatment decisions. 14 There is scant data to inform clinical decision making on management and whether to choose a surgical reattachment or a nonsurgical exercise-based treatment approach of these injuries. Both treatment options appear to have good return-to-sport (RTS) outcomes, 1,2,15,22,24,27 but there are no randomized controlled trials comparing these options.…”