Open Fractures of the Lower Limb

An open fracture of the lower limb is a fracture in which the broken bone communicates with the outside environment through a breach in the skin and soft tissues, most commonly affecting the tibia. It is an orthopaedic emergency because the exposed bone and devitalised tissue carry a high risk of deep infection, non-union and limb loss. In the UK, management is defined by the joint British Orthopaedic Association / British Association of Plastic, Reconstructive and Aesthetic Surgeons standard on Open Fractures (BOAST, December 2017) and NICE guideline NG37: early intravenous antibiotics, urgent transfer to a specialist orthoplastic centre, debridement timed according to contamination and energy of injury, and combined skeletal fixation with definitive soft tissue cover — the "fix and flap" approach.

How do open fractures of the lower limb present, and how are they assessed?

Most open lower limb fractures follow high-energy trauma (road traffic collisions, falls from height, crush injuries), although low-energy spiral fractures in the elderly can also breach fragile skin. Assessment follows ATLS principles — an open fracture is rarely the most immediately life-threatening injury in a polytrauma patient.

Limb-specific assessment, as per the December 2017 BOAST, requires that the examination documents the vascular and neurological status of the limb, repeated systematically after any reduction or splinting. Practical steps at first contact:

• Assess and record distal pulses, capillary refill and sensorimotor function, with timings.
• Remove only gross contamination; handle the wound as little as possible.
• Photograph the wound, then cover it with a saline-soaked gauze dressing sealed with an occlusive film — repeated wound inspections outside theatre increase infection risk.
• Realign and splint the limb, then reassess and re-document neurovascular status.
• A pulseless, deformed limb demands urgent realignment, splinting and repeated arterial assessment; the June 2026 BOAST on arterial injuries recommends CT angiography performed concurrently with whole-body trauma CT when arterial injury is suspected.

So-called "mini-washouts" in the emergency department are explicitly not recommended, and NICE NG37 similarly advises against irrigating open fractures of the long bones, hindfoot or midfoot before formal debridement.

What is the immediate management of an open fracture?

Three interventions dominate the first hour:

1. Antibiotics. The BOAST states that intravenous prophylactic antibiotics should be administered "as soon as possible, ideally within 1 hour of injury". NICE NG37 makes the same recommendation, extending it to the pre-hospital setting provided transport is not delayed. Local policy dictates the agent; typical UK regimens use co-amoxiclav or a cephalosporin, broadened for heavy contamination. Tetanus prophylaxis should be addressed as good practice.
2. Splintage and dressing. As above — photograph, saline-soaked dressing, occlusive film, realign, splint, re-examine.
3. Triage to an orthoplastic centre. Patients with open fractures of the long bones, hindfoot or midfoot should be taken directly, or transferred urgently, to a specialist centre that can provide combined orthopaedic and plastic surgical (orthoplastic) care. Definitive surgery in a unit without both specialties on site is a recognised source of avoidable morbidity.

How is the Gustilo–Anderson classification used?

The Gustilo–Anderson classification (Gustilo and Anderson, 1976; type III subdivided by Gustilo, Mendoza and Williams, 1984) grades open fractures by wound size, contamination, soft tissue injury and vascular status. It correlates with infection risk and guides reconstruction, but it is only reliably assigned after surgical debridement in theatre — a point interviewers frequently probe.

Heavily contaminated wounds (agricultural, aquatic or sewage exposure) are managed as grade III irrespective of wound size.

When should debridement be performed?

Timing is stratified by contamination and energy of injury, not by a blanket "six-hour rule", which has no place in modern UK practice. The December 2017 BOAST sets the following windows:

Debridement is a consultant-level combined orthoplastic procedure: all devitalised bone and soft tissue is excised, the wound extended along fasciotomy-safe incisions, and the limb lavaged. Where the limb is devascularised, the June 2026 arterial injury BOAST treats revascularisation as an emergency to be commenced within one hour of arrival — there is "no safe ischaemic time" — with temporary vascular shunting recommended to restore flow rapidly while the skeleton is stabilised.

What is the definitive management ("fix and flap")?

The management plan for fixation and coverage must be made jointly by orthopaedic and plastic surgery consultants — the defining feature of orthoplastic care. Principles:

• Cover within 72 hours. If definitive soft tissue closure or coverage is not achieved at primary debridement, it should be completed within 72 hours of injury.
• Internal fixation only with immediate cover. Definitive internal stabilisation (nail or plate) is only appropriate when it can be immediately covered by healthy soft tissue — otherwise a spanning external fixator provides temporary stability.
• Single-stage reconstruction where possible. The "fix and flap" strategy — radical debridement, definitive skeletal fixation and vascularised soft tissue cover (local fasciocutaneous, muscle or free flap) at one or two closely spaced sittings — was popularised by Gopal et al. (J Bone Joint Surg Br, 2000) for severe open tibial fractures, and underpins the current standard.
• Negative pressure wound therapy is not a substitute for cover. The WOLLF randomised trial (JAMA, 2018; 460 patients across the UK Major Trauma Network) found no improvement in 12-month disability with NPWT versus standard dressings for severe open lower limb fractures, at higher cost. NPWT may bridge to definitive cover but must not delay it.
• Amputation. Where the limb is unsalvageable, the decision is multidisciplinary — senior orthopaedic and plastic surgeons, rehabilitation specialists, the patient and family — and, when indicated, primary amputation should be performed within 72 hours. Scoring systems (e.g. MESS) are unreliable in isolation and should not replace consultant MDT judgement; this is good practice rather than a numbered standard.

What are the complications and prognosis?

• Fracture-related infection (FRI). The leading cause of poor outcome. The September 2019 BOAST on FRI requires deep sampling (five microbiological and two histology samples with separate instruments) before antibiotics in the non-septic patient, consultant review within 48 hours, and referral of chronic FRI, infected non-union and segmental defects to a bone infection MDT including orthopaedic and plastic surgeons, infection specialists and musculoskeletal radiologists.
• Compartment syndrome. Can coexist with an open fracture — an open wound does not decompress the compartments. As per the July 2025 BOAST, pain out of proportion and pain on passive muscle stretch mandate immediate assessment; at-risk limbs need hourly documented review, opiate doses recorded, and immediate surgical decompression once the diagnosis is made. A diastolic-minus-compartment pressure difference of less than 30 mmHg indicates increased risk in equivocal cases.
• Vascular injury and ischaemia (grade IIIC injuries) — managed emergently as above.
• Non-union, malunion and bone loss — segmental defects may need staged reconstruction (Masquelet technique or distraction osteogenesis) in a specialist unit.
• Prognosis worsens with increasing Gustilo grade, contamination, delayed soft tissue cover and smoking. Even well-managed grade IIIB tibial fractures carry a meaningful risk of deep infection and prolonged disability, which is why adherence to the timed pathway matters.

Key points

• IV antibiotics as soon as possible, ideally within 1 hour of injury (BOAST Dec 2017; NICE NG37).
• Photograph, saline-soaked dressing with occlusive film, realign, splint, re-document neurovascular status — no washouts outside theatre.
• Transfer long bone, hindfoot and midfoot open fractures directly to a specialist orthoplastic centre.
• Debridement: immediate if highly contaminated or devascularised; within 12 hours for high-energy; within 24 hours for low-energy injuries.
• Fixation and coverage planned jointly by orthopaedic and plastics consultants; definitive soft tissue cover within 72 hours; internal fixation only with immediate healthy cover.
• NPWT does not improve outcomes (WOLLF, JAMA 2018) and must not delay definitive cover.
• Unsalvageable limbs: MDT decision, amputation within 72 hours when indicated.