Aim: There has been increasing use of lateral extra articular procedures (LEAPs) in primary anterior cruciate ligament (ACL) reconstruction in an attempt to reduce the risk of graft rupture. Nonetheless, ACL graft ruptures still occur. Whether the LEAP remains structurally intact following ACL graft rupture is unknown. The aim of this study was to evaluate the magnetic resonance imaging (MRI) appearances of the LEAP at the time of ACL graft rupture.
Methods: 498 patients who had a primary ACL reconstruction with concomitant LEAP were identified through a prospectively collected database. Of these, 29 (5.8%) patients had a MRI confirmed ACL graft rupture. The post injury MRI scans were independently reviewed in axial, coronal and sagittal planes by four reviewers (2 knee surgeons, a knee fellow and a musculoskeletal radiologist). Each rater independently assessed for LEAP and concomitant knee injuries. Inter-rater reliability was assessed using Gwet's AC1 agreement coefficients. In cases of conflicting interpretation, the scans were re-evaluated until consensus was achieved. Consensus rates of LEAP injury are presented.
Results: The mean age of the patients was 17 years 11 months (SD 2.81) and 31% were female. Sixteen (55%) had a hamstring tendon graft and 13 (45%) had quadriceps tendon grafts. All LEAPs were a modified Ellison tenodesis. The mean time from surgery to re-injury was 712 days (SD 444). Inter-rater agreement for LEAP assessment was excellent (Gwet’s AC1 = 0.926). Following consensus review, all LEAPs remained intact and in continuity on MRI. The LEAP was identifiable on coronal and axial sequences in all cases, while sagittal visualisation was limited in 14% due to field-of-view constraints.
Conclusion: Following ACL graft rupture where a modified Ellison procedure was performed at the primary surgery, the LEAP appeared radiologically intact on the post graft rupture MRI in all cases.
