Perioperative management of open fractures in the lower limb

An open fracture is a fracture which communicates with the external environment through a wound in the skin. Severe open fractures are managed by both orthopaedic and plastic surgeons to address injuries in both the bone and soft tissue. This review outlines the management of open fractures in the lower limb from the initial patient presentation to operative management (including debridement, skeletal fixation, definitive soft tissue coverage) according to the standards jointly published by the British Orthopaedic Association (BOA) and the British Association of Plastic, Reconstructive and Aesthetic Surgeons (BAPRAS). Additionally, the decision-making between limb salvage or amputation will be explored. Finally, this review will discuss the patient’s postoperative care including wound care and management of potential complications that may arise such as infection, flap failure and fracture non-union.


Introduction
An open fracture is a fracture which communicates with the external environment through a wound in the skin (Mosheiff 2018). Open fractures are usually high energy traumatic injuries which may arise from sports, road traffic accidents or blast injuries in conflict zones (Jordan et al 2014). Open fractures are at a greater risk of infections, delayed union, non-union and delayed return to function compared to closed fractures particularly when they are not managed appropriately (Mosheiff 2018, Papakostidis et al 2011). The management of open fractures involves the removal of contaminants and non-viable tissue, followed by closure such that they are converted to closed fractures when the fracture is stabilised (Nanchahal et al 2009).
In the pre-hospital setting, members of the ambulance service team will identify the severity of the open fracture based on the pattern of fracture and soft tissue injury (NICE 2016a). Features of severe open fractures include significant fragmentation of the bone (comminution or segmentation), bone loss and skin loss such that tension-free closure is not possible following wound excision or injury to one of the major arteries of the leg. The complete criteria may be found in the guidelines jointly published by the British Orthopaedic Association (BOA) and the British Association of Plastic, Reconstructive and Aesthetic Surgeons (BAPRAS) (Nanchahal et al 2009). Severe open fractures would prompt direct transfer to a specialist centre with Orthoplastic care so that the injury can be managed by both orthopaedic and plastic surgeons (Nanchahal et al 2009). Where geographical barriers exist and the patient is in a critical condition, transfer to the specialist centre may be indirect via the nearest local emergency department so that intermediate care may be provided (NICE 2016b).

Primary survey (Advanced Trauma Life Support) and examination of the injured limb
The initial approach to the injured patient with an open fracture should follow Advanced Trauma Life Support (ATLS) principles where life-threatening problems are identified and managed in a logical, hierarchical sequence such that the most imminent threat to life is addressed first (Nanchahal et al 2009). This can be undertaken by anyone who is trained in ATLS (ATLS 2018). Firstly, the patient's cervical spine should be stabilised, followed by the assessment of their airway, breathing, circulation, disability (ie: assessment of their neurological state) and finally exposure of the patient which may be necessary to carry out a full examinationthis follows the mnemonic of ABCDE (airway, breathing, circulation, disability and exposure) (ATLS 2018).
The injured limb should be examined systematically and its neurovascular status documented before and after any manipulation (Nanchahal et al 2009). Should compartment syndrome or arterial injuries be suspected, management should be by the respective BOA Standards for Trauma and Orthopaedics (BOAST) guidelines (BOAST 2020) (see Table 1). The open fracture wound should also be photographed (Nanchahal et al 2009).
In 2016, NICE recommended intravenous morphine as the first-line analgesic for major trauma (including open fractures) and to adjust the dose as needed to achieve adequate pain relief. Outside of the sterile theatre environment, gross contaminants may be removed but exploration and irrigation of the wound are not recommended as they increase the risk of infection (Nanchahal et al 2009). A sterile saline dressing may be applied to the wound and sealed with an adhesive film for physical protection and from environmental contamination (Nanchahal et al 2009). The injured limb should then be re-aligned and splinted to ensure stability while the patient is in transit, otherwise, motion at the fracture site will add to the initial damage (Gueorguiev-Rüegg & Stoddart 2018).

Prophylactic antibiotics
Intravenous prophylactic antibiotics should be administered within 3h of injury or as soon as possible and the choice of antibiotics should consider the local trust guidelines and the patient's allergy status (Nanchahal et al 2009). BOA and BAPRAS guidelines propose intravenous co-amoxiclav (1.2g) or cefuroxime (1.5g) 8h, but if the patient is allergic to penicillin then clindamycin (600mg) should be given (Nanchahal et al 2009). The patient may also require tetanus prophylaxis depending on their vaccination history (Nanchahal et al 2009).

Imaging
When patients receive a trauma computed tomography (CT) scan to visualise the damage to the bones noninvasively, there should be protocols in place which may include a head-to-toe 'scanogram' which can then be used with clinical correlation to direct further specific limb sequences with or without CT angiography and avoid missing any findings and delays from re-scanning (NICE 2016b). Imaging is only useful if it may alter the approach to intervention; therefore it should only take place at a centre where an appropriate follow-up intervention is available; but if it were to be taken for use later, it should not delay transfer to the described centre (ATLS 2018).

Classification and scoring of open fractures
Classification systems aid the description of the open fracture injury, which may influence management or predict prognosis (Jordan et al 2014).
One example is the Gustilo-Anderson system which is best applied after wound debridement. Type I-III injuries were first described by Gustilo & Anderson (1976) and the Type III injuries were further subdivided by Gustilo et al (1984) (see Table 2).
There are also scoring systems designed to aid a surgeon in contemplating whether to amputate or salvage a severely injured lower limb, such as the

Operative management
Where the patient has mental capacity, their consent for any intervention will have to be sought (GMC 2008). If patients were unable to consent (eg: they are unconscious) in an emergency setting, healthcare professionals can treat the patient without their consent if the treatment is immediately necessary to save their life or to prevent a serious deterioration of their condition (GMC 2008).
A National Confidential Enquiry into Patient Outcome and Death (NCEPOD) classification is assigned by the surgeon to define the priority for surgical intervention, whether it is immediate (decision to operate within minutes), urgent (decision to operate within hours), expedited (decision to operate within days) or elective (timing of operation to suit patient, hospital and staff) (Alleway 2004). Where surgical intervention is neither immediate nor urgent, the anaesthetist should take a history from the patient (eg: allergies, smoking status) which may alter the approach to their operative and postoperative care (Verma et al 2010).

Formal debridement
The removal of contaminants and non-viable tissue, which may eventually become a focus of infection, from a wound is known as debridement (  Associated with an arterial injury requiring repair, irrespective of the degree of soft tissue damage

Definitive soft tissue reconstruction
Where the wound is too large to be closed directly, soft tissue reconstruction is performed (Simman 2009). The choice of soft tissue reconstruction follows the reconstructive ladder which explores the simplest to the most complex option, starting with skin grafts, local flaps and finally free flaps (Simman 2009) (see Table 4).
Studies have shown that if definitive soft tissue reconstruction is achieved earlier, flap survivability improves, infection rates are lower (Qiu et al 2018) and occurrence of osteomyelitis is reduced (Breugem & Strackee 2006). Therefore, current guidelines suggest that it should be achieved as promptly as possible after debridement and certainly within 72h of injury (BOAST 2020). It should be noted that the use of temporary dressings such as vacuum foam dressing does not nullify the negative outcomes associated with delaying soft tissue reconstruction and hence should never be a definitive substitute (Hou et al 2011).

Skeletal fixation
Skeletal fixation is required to keep the fracture ends in close apposition and stable so that bone healing (osteogenesis) can take place (Sathyendra & Darowish 2013). This stability may be absolute or relative to promote primary and secondary bone healing, respectively (Sathyendra & Darowish 2013).
Another important element that affects fracture healing is the blood supply and this is provided by the soft tissue surrounding the bone (Marsh & Li 1999), such that soft tissue damage can delay fracture union (Rommens & Broos 1992 Definitive internal fixation should only be carried out when it can be followed immediately with definitive soft Table 4 The reconstructive ladder (Simman 2009)

Types of soft tissue reconstruction Description
Skin graft involves the transplantation of the tissue, with or without its blood supply, from the donor site to the recipient wound site may be full thickness if they contain the epidermis and the entire dermis or split-thickness if they contain the epidermis with a portion of the dermis Local flap involves the transplantation of the tissue, together with its blood supply, from the donor site to the recipient wound site a local flap is located next to the wound and the skin is left attached on one end to preserve the blood supply while the other end is moved to cover the wound Free flap like a local flap, involves the transplantation of the tissue, together with its blood supply, from the donor site to the recipient site unlike a local flap, the free flap is obtained distant from the wound and the blood vessels are anastomosed by microsurgery tissue coverage, otherwise, the risk of infection may be increased significantly (Nanchahal et al 2009).
The exact method of fixation is determined by many factors including the degree of soft tissue injury, fracture location, fracture pattern, patient-related factors, the mechanism of injury and the surgeon's expertise (Mosheiff 2018).

The decision between limb salvage or primary amputation
When managing a patient with severe limb trauma, the decision for primary amputation should be weighed against the impact of limb salvage and reconstruction (Nanchahal et al 2009 Anti-embolism stockings should not be worn over wound areas. In these cases, pharmacological prophylaxis such as low-molecular weight heparin or direct oral anticoagulants may be preferred (NICE 2018

Wound care
While the patient is in the ward, the wound should be kept clean by having the wound cleansed and the dressing changed by medical staff to reduce surgical site infection (NICE 2021).

Non-union
Non-union is the failure of a fracture to heal, which will remain as such without further intervention (Elliott et al 2016). While septic non-union is caused by infection, aseptic non-union is caused by poor blood supply or poor bone stability preventing fracture healing (Elliott et al 2016). Aseptic non-union is divided into hypertrophic and atrophic non-union (Elliott et al 2016). Hypertrophic non-union occurs when poor stability at the fracture site becomes the limiting factor for fracture healing, while in atrophic non-union, poor vascular supply or insufficient mobilisation results in an impaired biological healing response (Elliott et al 2016). Further surgery may be required to revise the skeletal fixation, remove nonviable fracture ends or insert a bone graft to make up for the bone loss (Nanchahal et al 2009).

Compartment syndrome
Acute compartment syndrome refers to ischaemia of the muscles and nerves within a fascial compartment due to raised intra-compartmental pressure (ICP) which reduces tissue perfusion (Nanchahal et al 2009). This is a surgical emergency and a high index of suspicion must be maintained so that this is promptly diagnosed and treated by fasciotomy, where the fascia is cut to relieve the raised ICP (Nanchahal et al 2009). The key feature of compartment syndrome in the conscious patient is severe pain, out of proportion to the injury and aggravated by passive muscle stretch (BOAST 2020). In an obtunded patient (eg: due to delirium, intoxication, sedation) or when there are distracting injuries, there may be a role for ICP monitoring or serial ICP measurements of the affected limb (BOAST 2020).