Colles Fracture

Colles fracture is an extra-articular fracture of the distal radius with dorsal angulation and displacement of the distal fragment, within about 2.5 cm of the wrist joint, causing the typical "dinner fork" deformity. It follows a fall on the outstretched hand with the wrist extended.

Distal radius fractures account for about 1 in 6 of all fractures seen in emergency departments. The peak is in postmenopausal women aged 50 to 70, in whom it is often the first fragility fracture. A fracture of the ulnar styloid accompanies about half or more.

Features that predict instability and redisplacement are age over 60, dorsal angulation of over 20 degrees, dorsal comminution, an associated ulnar fracture, intra-articular extension and osteoporosis.

Complications are malunion, acute median nerve compression, complex regional pain syndrome (reported over a wide range), delayed rupture of extensor pollicis longus (3 to 8 weeks later, often after an undisplaced fracture), stiffness, post-traumatic arthritis and distal radioulnar joint dysfunction.

Pathophysiology.

Axial load on the extended wrist exceeds the strength of the cancellous distal radius metaphysis. Dorsal comminution, in osteoporotic bone, collapses the dorsal cortex and allows the distal fragment to tilt dorsally and shorten.

Normal values: radial inclination 22 degrees (range 13 to 30), volar tilt 11 degrees (range 0 to 20), radial height about 11 mm. Loss of these predicts poor grip and wrist pain.

Wrist pain, swelling and deformity, with tenderness over the distal radius, and reduced movement. Test the median nerve (numbness over the thumb, index, middle and radial ring fingers, thenar weakness), the ulnar and radial sensory nerves, and capillary refill. Look for skin tenting or wounds.

Examine the snuffbox (scaphoid), the distal radioulnar joint, the elbow and the shoulder. Ask about the cause of the fall (syncope, dizziness), anticoagulant use, and risk factors for osteoporosis.

• Radiographs: posteroanterior and lateral wrist. Measure radial inclination, volar tilt, radial height (shortening) and ulnar variance. Any articular step or gap over 2 mm needs CT.
• After reduction, the accepted position is radial shortening under 3 mm, dorsal tilt no more than 10 degrees (up to 20 degrees in low demand older patients), radial inclination of 15 degrees or more, and an articular step under 2 mm.
• CT for intra-articular extension and surgical planning.
• Bone health: serum calcium, 25-hydroxyvitamin D, creatinine, eGFR and, when indicated, bone densitometry. A fall assessment follows.

Differential diagnosis.

• Smith fracture and Barton fracture.
• Chauffeur fracture and scaphoid fracture.
• Perilunate dislocation and distal radioulnar joint injury.
• Pathological fracture and wrist sprain.

Reduction.

• Haematoma block: lidocaine 1% (10 mg/mL) 5 to 10 mL injected into the fracture haematoma with aseptic technique as a single administration (maximum 4.5 mg/kg of plain lidocaine and not exceeding 300 mg). Monitor for toxicity (perioral numbness, tinnitus, drowsiness). Avoid with infection at the site or lidocaine allergy, and reduce the volume in hepatic impairment. Procedural sedation or a Bier block are alternatives.
• Technique: finger trap traction for 5 to 10 minutes, disimpact, then volar flexion and ulnar deviation with thumb pressure on the distal fragment. Avoid the extreme wrist flexion and ulnar deviation (Cotton-Loder position), which causes median neuropathy.
• Short arm cast or volar slab with the wrist near neutral, for 5 to 6 weeks. Check the position on radiographs after reduction and at 1 and 2 weeks, since redisplacement is common in unstable fractures.

Surgery. Indications are failed reduction, unacceptable alignment after reduction (the values given for acceptable position), instability (dorsal comminution, shortening), open fracture, non-resolving median nerve symptoms, associated distal radioulnar joint instability, and an articular step.

• Volar locking plate through the flexor carpi radialis approach (most often used).
• Percutaneous Kirschner wires (1.6 mm) or external fixation for selected fractures.
• Low demand older adults with displaced fractures may be treated in a cast with similar function at 1 year.

Analgesia.

• Paracetamol 1 g orally every 6 hours as needed for up to 5 to 7 days (maximum 4 g daily; 3 g daily when weight is under 50 kg, with chronic alcohol use or hepatic impairment).
• Ibuprofen 400 mg orally every 8 hours with food for up to 5 days (maximum 1200 mg daily); avoid with eGFR under 30 mL/min/1.73 m2, peptic ulcer, heart failure or anticoagulant use.
• Oral morphine 5 to 10 mg every 4 hours as needed for severe pain for up to 3 days (start 2.5 to 5 mg with age over 75 or eGFR under 30 mL/min/1.73 m2; avoid exceeding 60 mg in 24 hours without senior review); monitor sedation and respiration and prescribe a laxative.

Complex regional pain syndrome prevention. Vitamin C (ascorbic acid) 500 mg orally once daily for 50 days from the day of injury (maximum 500 mg daily; the evidence is moderate). Avoid with a history of oxalate kidney stones, and limit with eGFR under 30 mL/min/1.73 m2. No routine monitoring.

Secondary prevention after a fragility fracture.

• Alendronate 70 mg orally once weekly, taken fasting with a full glass of water and kept upright for 30 minutes, for 5 years and then reassess (maximum 70 mg weekly). Check calcium, 25-hydroxyvitamin D and creatinine before starting and yearly. Avoid with eGFR under 35 mL/min/1.73 m2, uncorrected hypocalcaemia, or oesophageal stricture. Dental review before starting.
• Zoledronic acid 5 mg intravenously over at least 15 minutes once yearly (for 3 years, then reassess) when oral therapy is not tolerated and eGFR is 35 mL/min/1.73 m2 or over; check creatinine and calcium before each dose and ensure hydration.
• Colecalciferol 800 to 2000 IU orally daily, and dietary calcium to a total of 1000 to 1200 mg daily (supplement 500 to 600 mg daily only to cover shortfalls; maximum total 2000 mg daily). Correct vitamin D deficiency first.

Monitoring. Radiographs at 1 week, 2 weeks and 5 to 6 weeks. Median nerve, finger movement and extensor pollicis longus function at each visit. Signs of complex regional pain syndrome (disproportionate pain, swelling, colour change) at 2 to 6 weeks. Wrist range and grip at 3 months.

Referral and escalation. Refer displaced fractures to the fracture clinic within 1 week. Same day referral for open fracture, skin compromise, and acute carpal tunnel syndrome (worsening median nerve signs after reduction, in which case release excess flexion and decompress urgently if signs persist), or neurovascular compromise.

Special groups.

• Children: buckle and greenstick fractures of the distal radius need a cast or splint for 3 to 4 weeks.
• Older adults: investigate falls and bone health.
• Anticoagulated patients: a haematoma block is still possible, with pressure afterwards.
• Kidney impairment: avoid ibuprofen; avoid bisphosphonates at eGFR under 35 mL/min/1.73 m2; reduce morphine doses.
• Pregnancy: avoid bisphosphonates; treat with a cast and paracetamol.