External fixation devices are used to help immobilise a particular part of the body following a fracture or with certain orthopaedic problems to allow bone healing. They can allow the fixation and manipulation of multiple bone segments which would otherwise be very difficult. They involve the use of pins, wires and braces and are used when other options of immobilisation (such as plaster casts) would be ineffective (Singh 2016; Walker 2012).
These devices can be used in limb length discrepancy surgeries, nerve and tendon repairs, and polytrauma patients with fractures, to name a few incidences. External fixation devices include circular fixators such as halo thoracic braces, Ilizarov fixators, and unilateral fixators (different from circular fixators as they are only positioned on one side of the limb) (Singh 2016).
Risks of External Fixation Devices
There are many risks associated with the use of external fixation devices which include those as a result of the device itself, as well as the initial injury that requires fixation.
Pin site complications rates range from 7% – 100%, with the majority of complications being infection. This broad range of numbers is problematic and due to the lack of a universal classification for pin site infections (Walker 2012).
The risks of external fixation devices include:
- Infection – both pin site and osteomyelitis
- Deep vein thrombosis (DVT) and pulmonary embolisms (PE)
- Aseptic loosening
- Fracture or non-union of existing fracture; and
- Loss of reduction.
(Roberts et al. 2015; Vaidya et al. 2012)
(DVTs and PEs are also potential complications following orthopaedic surgery and are therefore potential complications for those with external fixation devices. However, there is limited evidence that the clots can be caused by the use of the devices themselves, and rather are more likely a result of the surgery (Roberts et al, 2015)).
Pins within the external fixator can also loosen. This can then create an unstable fixator, which results in an unsuitable environment for bone healing, increased movement in the limb and pin site irritation, which is often a precursor for pin site infection. Pins can loosen for a variety of reasons, one of which being when the pin is uncoated it can lead to a fibrous tissue formation where the pin meets the bone (Ferreira & Marais 2012).
Pin Site Infection
One of the most common risks involved when external fixation devices are used is infection. A pin site cannot heal whilst the pin and external fixator is in situ, therefore it is essential that pin site care is attended regularly to decrease the risk of potential infection.
One way of looking at pin site wound care is to think of a stab wound: a stab wound can’t heal if the knife is still in the wound, which is basically a description of a pin site wound. The healing of the site is prevented by the presence of the pin, therefore wound care revolves around keeping those sites clean and free from infection (Davies et al. 2005). (
(Read Ausmed’s Wound Care and Wound Healing Guide for more information.)
There are many individual factors that can also increase the risk of the individual developing pin site infection. These include the patient’s age, any pre-existing medical conditions, the cause of the need for the external fixation device, and the duration the device is needed.
A study also found that weather can have an impact on pin site infections, with the rate of infections found to be higher during the warmer seasons (Kao et al. 2015).
The risk of developing a pin site infection increases with the length of time the fixation device is in place. Pin site infections will usually begin as cellulitis, and treatment of the infection will depend on the type of infection.
In most cases, a minor superficial infection can be treated with increased pin site care in conjunction with oral antibiotic therapy (Walker 2012). Most infections respond to oral antibiotics as generally they are from a Staphylococcus Aureus infection, but sometimes they do extend into deeper tissues and bone causing osteomyelitis, septic arthritis and in some cases septicaemia (Walker 2012).
When severe infection occurs, the stability of the fixation can become impaired. This can result in the removal of the pin or wire, but even after its removal the infection can still linger (Davies et al. 2005). Thankfully, superficial infections are more common in patients with external fixation devices than more severe types of infection. However, even a superficial infection causes the individual pain and can interfere with their recovery and rehabilitation (Davies et al. 2005).
The early recognition of potentially infected pin sites is essential in managing the complication efficiently. This involves documentation and monitoring of all pin sites through regular pin site care. Nurses and patients should take particular note of the presence and extent of erythema, tenderness, swelling and discharge (Walker 2012).
Pin Site Care
There is little evidence to support one type of pin care protocol over another, and this can be attributed to the fact that there is no validated grading system or definition for pin site infections (Lee et al. 2011).
Some protocols involve the use of antiseptic solutions, others use pressure dressings to restrict the movement between the skin and the pin (Davies et al. 2005). The use of pressure dressings can be especially beneficial to those pins sites that are near joints, which tend to be more prone to infection due to increased amounts of movement (Davies et al. 2005).
Due to a lack of clear evidence there are many inconsistencies with pin site management and prevention of pin site infections, however the goal of management should be to prevent the colonisation of the pins and wires and therefore prevent infection (Walker 2012) with regular pin site care.
A popular method of pin site care involves using normal saline or an antimicrobial agent and gauze to clean the pin site areas. This can be done twice a day, daily or even weekly depending on protocols (Lee et al. 2011).
Pin site care protocols are dependent on a variety of factors and are often different depending on the preference of the surgeon, nurse, habit, consensus and basic principles of wound care (Davies et al. 2005). It must be remembered though that complete healing of the site is not the goal of pin site care, so some wound care techniques can be inappropriate (Davies et al. 2005).
Nurses must also ensure that patients are educated on the signs and symptoms of infection so this complication can be monitored, and also on any restrictions which may be enforced on them due to both their injury or surgery and the use of the external fixation device, which includes restrictions such as being non-weight bearing through the affected limb. It is also important to elevate the limb post-operatively and whenever the patient is not mobilising. This will help to reduce the oedema around the pins and therefore improve the environment around the pin sites (Ferreira & Marais 2012).
External fixation devices come with many risks and benefits to the patient. Due to a lack of clear consensus on definition, a pin site infection and, consequently, pin site care protocols, are lacking much reliable evidence. Therefore, many protocols and practices will vary dependent on a variety of factors, but it is important that any care given to the patient with an external fixator device is individualised to that person and their injuries.
- Davies R, Nayagam, S & Holt, N 2005, ‘The care of pin sites with external fixation’, The Journal of Bone and Joint Surgery, vol. 87, pp. 716-9, viewed 16 January 2017, https://www.researchgate.net/profile/…/links/5608e71408ae8e08c0946638.pdf
- Ferreira, N & Marais, LC 2012, ‘Prevention and management of external fixator pin track sepsis’, Strategies in Trauma and Limb Reconstruction, vol. 7, no. 2, pp. 67-72, viewed 16 January 2017, http://link.springer.com/article/10.1007/s11751-012-0139-2/fulltext.html
- Kao, HK, Chen, MC, Lee, WC, Yang, WE & Chang, CH 2015, ‘Seasonal temperature and pin site care regimen affect the incidence of pin site infection in pediatric supracondylar humeral fractures’, BioMed Research International, viewed 16 January 2017, https://www.hindawi.com/journals/bmri/2015/838913/
- Lee, CK, Chua, YP & Saw, A 2011, ‘Antimicrobial gauze as a dressing reduces pin site infection’, Clinical Orthopaedics and Related Research, viewed 16 January 2017, http://repository.um.edu.my/17697/1/10.1007_s11999-011-1990-z%5B1%5D.pdf
- Roberts, JS, Panagiotidou, A, Sewell, M, Calder, P & Goodier, D 2015, ‘The incidence of deep vein thrombosis and pulmonary embolism with the elective use of external fixators,’ Strategies in Trauma and Limb Reconstruction, vol. 10, no. 2, pp. 67-71, viewed 16 January 2017, http://link.springer.com/article/10.1007/s11751-015-0219-1/fulltext.html
- Singh, A 2016, ‘External Fixation Devices – Concept and Use’, Bone and Spine, viewed 16 January 2017, http://boneandspine.com/external-fixation-devices/
- Vaidya, R, Kubiak, EN, Bergin, PF, Dombroski, DG, Critchlow, RJ, Sethi, A & Starr, AJ 2012, ‘Complications of anterior subcutaneous internal fixation for unstable pelvis fractures: A multicenter study’, Clinical Orthopaedics and Related Research, vol. 470, no. 8, pp. 2124-31, viewed 16 January 2017, http://pubmedcentralcanada.ca/pmcc/articles/PMC3392373/
- Walker, J 2012, ‘The problem with pin site infection’, Journal of Nursing and Care, viewed 16 January 2017, https://www.omicsgroup.org/journals/the-problem-with-pin-site-…aid=6565