Bilateral lunotriquetral coalition: a dynamic four-dimensional computed tomography technical case report

Area of Science:

• Orthopedics
• Radiology
• Biomechanics

Background:

• Lunotriquetral coalitions are the most frequent carpal coalition type.
• They result from the failure of apoptosis in the cartilage between lunate and triquetrum ossification centers.
• These coalitions can impact wrist biomechanics and potentially cause pain.

Purpose of the Study:

• To examine the arthrokinematics of bilateral lunotriquetral coalitions.
• To compare wrist joint motion in asymptomatic and injured wrists with lunotriquetral coalitions.
• To assess the utility of 4D CT with photon-counting detector technology in evaluating wrist variant anatomy.

Main Methods:

• A technical case report analyzing bilateral lunotriquetral coalitions with dissimilar Minnaar types.
• Static and dynamic (4D) CT imaging during pronosupination using a photon-counting detector CT scanner.
• Calculation of interosseous proximity distributions to quantify arthrokinematics.

Main Results:

• Differences in interosseous proximity distributions were observed between asymptomatic and injured wrists during resisted pronosupination.
• Altered wrist kinematics associated with lunotriquetral coalitions were identified.
• The technical feasibility of 4D CT with photon-counting detector technology was demonstrated.

Conclusions:

• Altered wrist arthrokinematics due to lunotriquetral coalitions may be a source of ulnar-sided wrist pain.
• Radiographic examination of specific anatomy is recommended for patients with lunotriquetral coalitions.
• 4D CT with photon-counting detector technology is a viable tool for assessing wrist arthrokinematics in variant anatomy.