The conflict in Afghanistan was defined by the use of the Improvised Explosive Device (IED) by the insurgent forces. The use of the IED and increased survivorship of casualties with extensive wounds has created a large cohort of multiple amputees. This has resulted in the identification of conditions not previously seen in common medical practise such as Heterotopic Ossification (HO).
HO is the formation of bone at sites other than the skeletal system and causes difficulty to the patient during rehabilitation through pain, pressure sores and infections thereby necessitating surgery to excise the problematic lesion, further delaying recovery. This thesis will examine HO in the context of the British Military experience.
After the withdrawal of British troops from Afghanistan in 2015, it was possible to calculate the entire amputee cohort and the HO burden to the British Armed forces. This was in order to identify risk factors for the formation of HO and calculate the clinical consequence and workload in managing these patients developing HO. A systematic review identified that through the bio-imaging of HO, and analysis of the morphological appearance and the matrix components, the pathophysiology surrounding its formation can be assessed.
The formation of HO is likely to be systemically driven by the large injury burden as measured by a significantly higher injury severity. Local factors, such as zone of injury and subsequent amputation, direct us to the location in which HO will form. Furthermore HO is bone; it has a lamella structure with a central haversian canal; lacunae exist within the matrix which itself consists of a distinct mineral phase. Evidence of bone turnover exists; however, this does not result in the formation of an organised ultra-structure. HO has lost the ability to re-model or the mechanical environment during its formation does not allow such organisation.