How should I manage a 58-year-old woman who developed medial wrist pain, swelling, and bruising after lifting a heavy object, with plain radiographs showing a subcentimeter lateral bone fragment and underlying osteoarthritis but no obvious fracture or dislocation?

Management of Acute Wrist Injury with Bone Fragment and Osteoarthritis

This patient requires advanced imaging with MRI to exclude an occult fracture or ligamentous injury, followed by conservative management with immobilization, analgesia, and close clinical follow-up.

Initial Diagnostic Approach

The plain radiographs showing a subcentimeter lateral bone fragment without obvious fracture or dislocation are concerning but insufficient to exclude significant injury. The clinical presentation—acute onset pain, swelling, and bruising after trauma—warrants further investigation despite "negative" radiographs for acute fracture 1.

Why MRI is Essential

• MRI without IV contrast is the appropriate next study when radiographs are nondiagnostic but clinical suspicion for occult fracture, ligamentous injury, or bone contusion remains high 1.
• Radiographically occult fractures are common in wrist trauma, and MRI has high sensitivity for detecting bone marrow edema, trabecular microfractures, and soft tissue injuries that plain films miss 1.
• The bone fragment seen on X-ray could represent an acute avulsion fracture, chronic degenerative change, or post-traumatic fragment—MRI will clarify its acuity and associated soft tissue damage 1.
• Ligamentous injuries (particularly scapholunate or lunotriquetral ligament tears) frequently accompany wrist trauma and can cause chronic instability if missed 1.

Alternative if MRI Unavailable

• CT without IV contrast is an acceptable alternative if MRI is contraindicated or unavailable, though it is less sensitive for soft tissue and bone marrow changes 1.
• CT provides excellent detail of cortical bone and can identify subtle fracture lines, particularly in the scaphoid, distal radius, and carpal bones 1.

Immediate Management Pending Imaging

Immobilization and Protection

• Immobilize the wrist in a volar splint or short-arm cast to prevent further injury while awaiting advanced imaging 1.
• Avoid manipulation of the wrist prior to definitive diagnosis to prevent displacement of occult fractures 1.

Pain Management

• Acetaminophen is first-line for mild to moderate pain in the setting of underlying osteoarthritis 2, 3.
• NSAIDs (ibuprofen, naproxen) are more effective for moderate-to-severe pain and acute inflammation, though gastrointestinal risk must be considered 2, 3.
• Ice application and elevation reduce swelling and provide symptomatic relief 3.

Interpretation of the Bone Fragment

The "subcentimeter fragmentation" described requires careful consideration:

• Acute avulsion fracture at ligamentous attachment sites (e.g., triquetrum, ulnar styloid) can appear as small bone fragments and indicate significant ligamentous injury 1.
• Chronic degenerative changes from underlying osteoarthritis can produce loose bodies or osteophyte fragments, but these would not explain acute swelling and bruising 2, 4.
• Post-traumatic fragment from previous injury may be incidental, but the acute clinical presentation suggests new pathology 1.

Common Pitfalls to Avoid

• Do not dismiss the injury based on "no acute fracture" on plain films—occult fractures are frequently missed initially and can progress to nonunion or chronic instability 1.
• Do not assume the fragment is chronic without advanced imaging, as acute avulsion fractures require different management than degenerative changes 1.
• Do not delay immobilization while awaiting MRI—early protection prevents displacement and further soft tissue injury 1.
• Do not overlook associated injuries such as distal radioulnar joint instability or triangular fibrocartilage complex tears, which commonly accompany wrist trauma 1.

Follow-Up Based on MRI Results

If Occult Fracture Identified

• Scaphoid fracture: Cast immobilization for 6-12 weeks with repeat imaging to assess healing 1.
• Distal radius fracture: Treatment depends on displacement and stability—may require orthopedic referral for fixation 1.
• Carpal bone fracture: Prolonged immobilization and close monitoring for avascular necrosis risk 1.

If Ligamentous Injury Identified

• Significant ligamentous tears (complete scapholunate or lunotriquetral dissociation) require orthopedic or hand surgery referral for potential surgical repair 1.
• Partial tears may be managed conservatively with prolonged immobilization (6-8 weeks) and rehabilitation 1.

If Only Bone Contusion/Soft Tissue Injury

• Continue immobilization for 2-4 weeks followed by gradual mobilization and physical therapy 1.
• NSAIDs for symptomatic relief during the healing phase 2, 3.

Management of Underlying Osteoarthritis

The presence of osteoarthritis complicates management and may affect healing:

• Osteoarthritis increases risk of poor functional outcomes and chronic pain after acute injury 2, 5, 6.
• Long-term management includes weight management (if applicable), exercise therapy, and consideration of disease-modifying supplements (glucosamine/chondroitin) for moderate-to-severe symptoms 2, 3.
• Corticosteroid injections may provide short-term relief for OA flare-ups but should not be used acutely in the setting of possible fracture 3.