New Concepts in Carpal Instability Including Modular Approach to Arthroscopic and Minimally Invasive Reconstruction

Mark Ross^1,2,3, Greg Couzens^1,2,4, Matthew Curran⁵, Nick Smith^6,7, Sanjeev Kakar⁸, Scott W Wolfe⁹

¹Brisbane Hand and Upper Limb Research Institute, Brisbane, Australia
²Orthopaedic Department, Princess Alexandra Hospital, Brisbane, Australia
³School of Medicine, University of Queensland, Brisbane, Australia
⁴Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
⁵Division of Plastic Surgery, University of Alberta, Edmonton, Canada
⁶Macquarie Hand Unit, Macquarie University Hospital, Macquarie Park, New South Wales, Australia
⁷Faculty of Medicine and Health Sciences, Macquarie University, Macquarie Park, New South Wales, Australia
⁸Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA
⁹Hand and Upper Extremity Service, The Hospital for Special Surgery, New York, NY, USA

HYPOTHESIS
The study proposes a modular approach for treating carpal instability, focusing on addressing ligamentous disruptions that contribute to dissociative and non-dissociative carpal instability. It is hypothesized that identifying and targeting specific ligament lesions using minimally invasive and arthroscopic treatment modules will yield predictable results and reduce the risk of complications associated with traditional methods.

METHODS
The modular approach involves identifying patterns of scaphoid flexion and increased scapholunate (SL) angle in dissociative SL instability. Ligamentous disruptions, including dorsal capsular compromise, deep portion of DICL (DSLT ligament) attenuation, and compromise of LRL and volar scaphotrapeziotrapezoid (STT) joint restraints, are identified. The study presents an algorithm for deploying various treatment modules, such as A/S RADiCL repair, modified midcarpal-based wide Mathoulin ADCLR, minimally invasive (MIS) volar STT reconstruction, and volar arthroscopic LRL capsuloplasty.

RESULTS
Early results of employing different combinations of modular treatments targeting specific kinematic problems are presented. The study demonstrates that the ligament-specific approach provides predictable outcomes, and the use of minimally invasive modules helps mitigate the risk of complications compared to traditional methods like "Holing" and tape application in small carpal bones.

SUMMARY

• The modular approach focuses on ligamentous disruptions causing carpal instability.
• Specific ligament lesions are identified, and minimally invasive and arthroscopic modules are used for targeted treatment.
• An algorithm is presented for deploying various treatment modules, including A/S RADiCL repair, wide Mathoulin ADCLR, MIS volar STT reconstruction, and volar arthroscopic SL capsuloplasty.
• Early results indicate predictability and reduced complications compared to traditional methods.
• The modular ligament-specific approach offers a promising strategy for addressing carpal instability, providing predictability in outcomes and minimizing the risk of complications associated with conventional techniques.