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OR2.1-6 | Upper Limb Fractures — PBL Case

CLINICAL SETTING

Dr Anand Rajan, the orthopaedic resident on call, is paged to the Emergency Department at 11 PM. A 52-year-old schoolteacher named Mrs Priya Subramaniam has arrived by ambulance following a road traffic accident. She was a front-seat passenger in a car that was rear-ended at high speed. She is alert and oriented, her GCS is 15, and her primary survey reveals no life-threatening injuries. She complains of severe pain in her left wrist and forearm. Her past history includes well-controlled hypertension (amlodipine 5 mg), hypothyroidism (levothyroxine 50 mcg), and one prior episode of peptic ulcer disease five years ago. She is a non-smoker and non-drinker. On examination of the left upper limb: there is gross deformity at the wrist, with dorsal displacement and dinner-fork appearance. The forearm appears normal on inspection. Radial pulse is palpable but diminished. Sensation is intact in all fingers. X-rays of the wrist reveal a fracture of the distal radius with dorsal tilt of 25° and 4 mm of radial shortening. No fracture of the ulna styloid is apparent, but the DRUJ appears widened on the PA view. X-rays of the forearm reveal no fracture of the ulnar shaft.

Trigger 1: Defining the Injury

The attending consultant reviews the X-rays. The PA wrist X-ray shows a fracture of the distal radius with 4 mm radial shortening and a 25° dorsal tilt. On the lateral view, the dorsal displacement is confirmed. Importantly, the PA X-ray reveals widening of the DRUJ space and the ulnar head appears slightly prominent on the lateral view, despite no fracture of the ulnar shaft or styloid. The consultant tells the resident: 'This is not a straightforward Colles — look at the DRUJ carefully. And look at the volar cortex of the radius on the lateral. What is this injury pattern?'

DISCUSSION POINTS

  • What fracture pattern is suggested by a distal radius fracture combined with DRUJ widening and no ulnar shaft fracture? How does this differ from a Monteggia fracture?
  • Define Colles fracture and describe its classic X-ray features. What mechanism of injury produces a Colles fracture versus a Smith fracture?
  • What is the significance of DRUJ disruption in a distal radius fracture? How does it change the management plan?
  • Classify this open or closed? Is any component of this fracture-dislocation a 'fracture of necessity' requiring operative fixation?
Click to reveal Trigger 2: Overnight Deterioration (discuss previous trigger first!)

Trigger 2: Overnight Deterioration

Mrs Subramaniam is taken to theatre at 2 AM for closed reduction and K-wire fixation under image intensifier. The radius is reduced to near-anatomical alignment (dorsal tilt corrected to 5°, shortening reduced to 1 mm). However, after radius fixation, intraoperative stress testing shows persistent DRUJ instability — the ulnar head subluxes with forearm supination. The surgeon stabilises the DRUJ with two K-wires in slight supination and applies an above-elbow backslab. She is admitted for post-operative monitoring. At 6 AM, the nursing staff note that she is complaining of increasing pain in the left forearm — 9/10 on NRS. The forearm feels firm. She has pins and needles in all fingers. The K-wires are intact and the plaster looks correctly applied. Radial pulse is present.

DISCUSSION POINTS

  • What is the most likely diagnosis for worsening forearm pain with a tense forearm, despite an intact radial pulse? Why does the presence of a pulse NOT exclude this diagnosis?
  • What is the delta pressure rule for compartment syndrome? State the threshold for fasciotomy.
  • Which compartments of the forearm are at risk? Describe the clinical signs of volar forearm compartment syndrome.
  • What is the surgical management of forearm compartment syndrome? Describe the incisions required.
Click to reveal Trigger 3: Post-Operative Analgesia and Follow-Up (discuss previous trigger first!)

Trigger 3: Post-Operative Analgesia and Follow-Up

Forearm compartment pressures are measured: volar compartment pressure = 42 mmHg; diastolic BP = 68 mmHg. Delta P = 26 mmHg (below the 30 mmHg threshold). Urgent fasciotomy is performed and the wound is left open; she is taken back for wound closure 48 hours later. At this stage she is alert and comfortable. The orthopaedic team must now prescribe post-operative analgesia. The intern suggests a course of diclofenac 50 mg TDS for 5 days. The consultant disagrees. At the 6-week follow-up clinic, X-rays show the radius fracture uniting in good alignment, but the patient asks: 'Doctor, I have pain in my other wrist too — my right wrist has been aching for months. My GP gave me some pain tablets, but they upset my stomach.' She also mentions she has been told she has early osteoporosis.

DISCUSSION POINTS

  • Why is diclofenac an inappropriate post-operative analgesic for Mrs Subramaniam? What safer alternatives would you prescribe, and in what sequence (analgesic ladder)?
  • The patient's right wrist pain with history of PUD raises the question of analgesic selection for a chronic pain scenario. What agents are safe, and what precautions apply for NSAIDs when PUD is a concern?
  • What is the relevance of osteoporosis to distal radius fractures? How would you advise this patient regarding bone health and fracture prevention?
  • Outline the rehabilitation plan for this patient following DRUJ stabilisation and fasciotomy. What are the expected functional milestones at 6 weeks, 3 months, and 6 months?

Learning Issues

Research these questions and bring your findings to the discussion.

  1. [OR2.6] What are the X-ray criteria for operative versus conservative management of distal radius fractures? What is the role of volar locking plates versus K-wire fixation in unstable distal radius fractures?
  2. [OR2.5] Describe the Galeazzi fracture-dislocation: mechanism, X-ray findings, operative approach, and intraoperative DRUJ assessment. How does it differ from the Monteggia injury?
  3. [OR2.4] What are the pathophysiology and diagnosis of forearm compartment syndrome? What is the delta pressure rule and what are the fasciotomy incisions for the forearm?
  4. [OR2.3] What are the contraindications to NSAIDs in post-operative orthopaedic patients? How do you construct a safe analgesic ladder for patients with PUD history and/or renal impairment?
  5. [OR2.1] What are the indications for surgical versus conservative management of clavicle fractures? What classification system is used and what are the common complications?
  6. [OR2.2] Apply the Neer classification to proximal humerus fractures. What are the indications for hemiarthroplasty versus ORIF in elderly patients with Neer four-part fractures?