Learning objectives
Review normal MRI features of the different types of ACL repair and reconstruction.
Review the current literature on tunnel positioning.
Review the MRI features of ACL and related complications.
Review the MRI features that would indicate risk of graft failure,
contralateral injury and early onset osteoarthritis.
Background
Anterior Cruciate ligament injury is one of the commonest ligamentous injuries requiring surgery.
ACL reconstruction is the Gold Standard but new techniques are being developed and there is increasingrenewed interest in primary repair on selected patients as well as reconstruction in the skeletally immature.
Although X-ray and CT are useful postsurgical baseline imaging tools,
MRI represents a complete postoperative imaging tool because of its ability to non-invasively identify and differentiate normal postoperative features,
assess tunnel placement and graft maturation and incorporation,
recognise graft failure and...
Imaging findings OR Procedure Details
1.SURGICAL TECHNIQUES AND GRAFT TYPES
A.
Primary Repair
ACL reconstruction remains the gold standard but there is recent renewed interest in primary athroscopic repair in selected patientswhere the tear isproximal and >75% of the distal tendon is intact and of good quality.
Surgical techniques include:
athroscopic suturing
transosseous pullout
suture anchor +/- internal augmentation
In arthroscopic suturing the only finding may belinear and/or heterogenous signal withinthe graft (Fig. 1) which can persist for over a year.
In the transosseous pullout technique small drill holes are...
Conclusion
MRI is a complete tool for the imaging of ACL reconstruction and repair because of its ability to noninvasively assess the graft and surgical tunnels as well as differentiate normal graft maturation from complications of surgery.
Further value lies on its ability to identify missed injuries and other risk factors for future complications includingearly onset osteoarthritisand contralateral ACL rupture.
References
1.
Knee Imaging Following Anterior Cruciate Ligament Reconstruction: The Surgeons and Radiologists Perspectives.
Seminars in Musculoskeltal Radiology Vol 22.
No.
4/2018.
2.
Postoperative imaging of anterio cruciate ligament reconstruction techniques acorss the spectrum of skeletal maturity.
Skeletal Radiology (2016) 45:517-530.
3.
Arthroscopic primary repair of the anterior cruciate ligament: what the radiologist needs to know.
Skeletal Radiology (2018) 47:619-629.
4.
Magentic Resonacnce imaging after anterior cruciate ligament reconstruction: A practical guide.
Grassie et al.
World Journal of Orthopaedics 2016 October 18; 7(10): 638-639.
5.
Imaging...