2025 ISAKOS Biennial Congress ePoster
Medial Instability Of Ac Joint; Clinical And Radiological Testing
Gregory A. Hoy, FRACS, FAOrthA, FACSP, FASMF, Melbourne, VIC AUSTRALIA
Melbourne Orthopaedic Group, Melbourne, Victoria, AUSTRALIA
FDA Status Cleared
Summary
Newer methods of testing and imaging AC instability can assist in decisions regarding reconstruction
ePosters will be available shortly before Congress
Abstract
Introduction
The classical Rockwood classification of AC injuries (Gorbaty) is not a good clinical indicator of who needs surgical correction. There have been numerous attempts at widening the classification to include assessments of horizontal plane instability (Beitzel, Aliberti), but with variable levels of penetration in published material. There is no current algorithm that associates clinical and radiological findings with surgical indications.
Methods
We present a simple clinical test that can demonstrate clinical medial instability and demonstrate which athletes require early reconstruction.
We assessed elite level contact sportsmen playing professional Australian Rules Football (Australian Football League (AFL) listed players) undergoing a twin-tailed dog bone reconstruction (Hoy et al) with an additional internal brace using our own technique allowing very early return to sport (Borbas et al) that have undergone 4D CT scans before and after reconstruction to demonstrate the correction of medial instability .
Results
CLINICAL TEST: Resisted ER / Manual medial instability / collapsing shoulder
The mechanism of AC instability has been considered landing on the point of the shoulder. We have clear demonstration that side to side impact is a classic mechanism in contact sports
We postulate the mechanism is semi-independent of the vertical separation of the conoid ligament. We demonstrate a reproducible and easy mechanism of testing medial instability in the AC Joint.
We also demonstrate radiological parameters of this instability including 4D CT scans confirming the instability.
SURGICAL FIXATION:
We then demonstrate the technique of how use of a circumferential internal brace adds significantly to the stiffness of the twin-tailed dog bone construct previously published.
Discussion
AC Joint instability in the setting of contact sports requires reconstruction using both coraco-clavicular and acromio-clavicular fixation. When used this way, we have managed to return AFL players to full competition sport at an average of 7 weeks, but with several players returning at 5 weeks with no discernible problem or complication.