What condition causes ulnar‑side wrist pain with limited supination of the hand?

Distal Radioulnar Joint (DRUJ) Instability with TFCC Injury

Ulnar-side wrist pain with inability to fully supinate the palm most likely indicates distal radioulnar joint (DRUJ) instability, often associated with triangular fibrocartilage complex (TFCC) injury. 1, 2

Clinical Reasoning

The combination of ulnar-sided pain and restricted supination is highly specific for DRUJ pathology because:

• The DRUJ is essential for forearm rotation (pronation-supination), and injury to its stabilizing structures directly limits this motion 2, 3
• TFCC tears, particularly peripheral detachments at the foveal attachment, destabilize the DRUJ and prevent normal supination mechanics 1
• Dynamic subluxation of the extensor carpi ulnaris (ECU) tendon during forced supination can also cause ulnar pain with supination limitation 4, 5

Diagnostic Approach

Initial Imaging

• Obtain three-view wrist radiographs first (posteroanterior, lateral, oblique in neutral position) to exclude fractures, assess ulnar variance, and identify static instability 1, 6
• The lateral view is critical for demonstrating malalignments and soft-tissue swelling 6, 7

Advanced Imaging for Persistent Symptoms

• 3.0T MRI without contrast is the appropriate next study, with sensitivity of 63-100% and specificity of 42-100% for TFCC tears 1
• MRI accurately depicts TFCC, intrinsic/extrinsic ligaments, DRUJ stability, and ECU tendon pathology 4
• For suspected ECU subluxation, dynamic sequences in pronation and supination are essential, as static MRI may miss dynamic instability 4

When to Use MR Arthrography

• Reserve MR arthrography for surgical planning or when standard MRI is equivocal, as it has higher sensitivity (63-100%) and specificity (89-97%) for TFCC tears 1
• For ulnar-sided TFCC detachment, add DRUJ injection to the standard radiocarpal injection 4, 1

CT for DRUJ Instability

• CT is the modality of choice for evaluating DRUJ stability, imaging both wrists simultaneously in maximal pronation, neutral, and maximal supination 4
• CT arthrography has nearly 100% sensitivity and specificity for TFCC lesions when MR arthrography is contraindicated 1

Common Pitfalls

• Do not rely on conventional arthrography alone, as it has only 76% sensitivity for full-thickness tears and misses partial tears entirely 1
• Dynamic ECU subluxation requires specific imaging protocols—standard static MRI will miss this diagnosis 4
• Ultrasound can show dynamic ECU subluxation during forced supination but requires experienced operators 4

Key Differential Diagnoses

The "storey concept" helps systematically evaluate ulnar-sided wrist pain 8:

• Lower storey (DRUJ level): DRUJ instability, TFCC tears, ulnar styloid fractures 8, 2
• Intermediate storey (radiocarpal level): TFCC central perforations, ulnar impaction syndrome 8, 9
• Upper storey (midcarpal level): Lunotriquetral ligament tears, pisotriquetral arthritis 8, 9

For your specific presentation (ulnar pain + limited supination), focus on the lower storey pathologies 8, 2

Management Principles

• Immobilization in neutral wrist and forearm position for 4 weeks is recommended for conservative management 1
• Arthroscopic foveal repair with suture anchor for peripheral TFCC tears (Palmer 1B) restores anatomic attachment critical for DRUJ stability 1
• Difficulty carrying loads in the hand is a major functional constraint that indicates significant DRUJ pathology requiring intervention 2