Ulnar Wrist Fracture (Distal Radius Fracture) – A Complete Patient‑Friendly Guide

Overview

A distal radius fracture is a break in the radius bone near the wrist. When the fracture extends into the ulnar side of the wrist joint, it is often referred to as an ulnar wrist fracture or a “distal radius fracture with ulnar involvement.” This injury is one of the most common orthopedic problems in adults, especially among older adults who have weaker bones.

• Incidence: In the United States, roughly 640,000 distal radius fractures occur each year; about 20‑30% involve the ulnar styloid or the distal ulna ^[1].
• Age groups: Bimodal distribution – peaks in children (fall from a height) and in adults > 60 years (osteoporotic bone).
• Gender: Women are 2–3 times more likely to sustain the injury after menopause due to osteoporosis.

Symptoms

Symptoms can range from mild discomfort to severe pain and loss of function. Common presentations include:

• Pain: Immediate, sharp pain at the wrist that worsens with movement or pressure.
• Swelling & bruising: Rapid onset of swelling; the skin may turn blue or purple.
• Deformity: A visible “dinner‑fork” or “bayonet” shape of the forearm due to radial shortening or dorsal angulation.
• Limited range of motion: Difficulty turning the hand, wrist flexion, extension, pronation, or supination.
• Loss of grip strength: Inability to hold objects firmly.
• Numbness or tingling: Especially in the thumb, index finger, or the ulnar side of the hand if a nerve is compressed.
• Instability: A feeling that the wrist may “give way” when pressure is applied.
• Visible fracture fragment: In some cases, a piece of bone (often the ulnar styloid) may be palpable under the skin.

Causes and Risk Factors

What Causes an Ulnar Wrist Fracture?

Most fractures result from a fall onto an outstretched hand (FOOSH). The force travels up the wrist, fracturing the distal radius and, if the load is directed toward the ulnar side, the ulnar styloid or distal ulna may also break.

• High‑energy trauma: Motor vehicle collisions, sports collisions, or falls from height.
• Low‑energy falls: Trip or slip and land on a hand—common in older adults with osteoporotic bone.
• Direct blow: Less common but can occur in contact sports.

Risk Factors

• Age ≥ 60 years – decreased bone density.
• Post‑menopausal women – estrogen loss accelerates osteoporosis.
• Chronic steroid use – glucocorticoids weaken bone.
• Previous wrist fractures – indicates weaker bone architecture.
• Low bone mineral density (BMD) – diagnosed by DEXA scan.
• Alcohol misuse – impairs balance and bone health.
• Neuromuscular disorders – e.g., Parkinson’s disease, which increase fall risk.
• Occupational hazards – jobs requiring frequent gripping or falling from ladders.

Diagnosis

Timely and accurate diagnosis is essential to restore wrist function and avoid long‑term problems.

Clinical Evaluation

• History: Mechanism of injury, pain onset, prior wrist problems, medication use (especially anticoagulants).
• Physical exam: Inspection for swelling/deformity, palpation for tenderness over the distal radius and ulnar styloid, assessment of neurovascular status (radial & ulnar pulses, sensation in median, ulnar, and radial nerves).

Imaging Studies

1. Plain Radiographs (X‑ray): Two‑view (posteroanterior & lateral) is the standard. It identifies fracture lines, displacement, involvement of the ulnar styloid, and joint incongruity.
2. Computed Tomography (CT): Offers three‑dimensional detail, useful for complex intra‑articular fractures or when surgical planning is required.
3. MRI: Reserved for suspected soft‑tissue injury (e.g., ligament tears, scaphoid fracture) or when plain films are equivocal.

Classification Systems

Understanding fracture patterns guides treatment. Commonly used systems include:

• AO/OTA classification: Categorizes fractures by location (extra‑articular vs. intra‑articular) and complexity.
• Frykman classification: Specifically addresses distal radius fractures with or without ulnar involvement and the presence of associated injuries.

Treatment Options

Treatment ranges from non‑operative immobilization to surgical fixation, depending on fracture stability, displacement, patient age, activity level, and health status.

Non‑Surgical Management

• Closed reduction: Manual manipulation to realign bone fragments, performed under sedation or nerve block.
• Immobilization:
  • Short arm cast or splint for 4–6 weeks.
  • Removal of the cast followed by gradual motion exercises.
• Analgesia: Acetaminophen, NSAIDs (if no contraindication), or short‑course opioids for severe pain.
• Adjuncts: Vitamin D and calcium supplementation in osteoporotic patients.

Surgical Management

Surgery is indicated when the fracture is unstable, displaced > 2 mm, angulated > 10°, or involves the joint surface.

• Open Reduction & Internal Fixation (ORIF):
  • Plate and screw constructs restore anatomy.
  • Allows early wrist motion, reducing stiffness.
• External Fixation:
  • Pins inserted proximal and distal to the fracture; a frame maintains alignment.
  • Often combined with percutaneous K‑wire pinning of the ulnar styloid.
• Percutaneous Pinning (K‑wires):
  • Minimally invasive, useful for minimally displaced fractures.
• Volar locking plates: Particularly effective for dorsally displaced fractures.

Rehabilitation

Regardless of treatment type, hand therapy is crucial:

• Phase 1 (0–2 weeks): Gentle finger flexion/extension, edema control.
• Phase 2 (2–6 weeks): Passive/active assisted wrist motion, forearm rotation.
• Phase 3 (6–12 weeks):** Strengthening with grip exercises, gradual return to functional tasks.