The UK Military Trauma Registry was searched for all RN/RM personnel injured between March 2003 and April 2013. These records were then cross-referenced with the records of the Naval Service Medical Board of Survey which evaluates injured RN/RM personnel for medically discharge, continued service in a reduced capacity or return to full duty (RTD). Population at risk data was calculated from service records.

There were 277 casualties in the study period: 61 (22%) of these were fatalities; of the 216 survivors, 63 or 29% were medically discharged; 24 or 11% were placed in a reduced fitness category. A total of 129 individuals (46% of the total and 60% of survivors) returned to full duty. The greatest number of casualties was sustained in 2007; there was a 3% casualty risk per year of operational service between 2007–2013. The most common reason cited by the Naval Service medical board of survey for medical downgrading or discharge was injuries to the lower limb with upper limb trauma being the next most frequent injury.

This study characterises the injuries sustained by RN and RM personnel during recent conflicts and demonstrates significant challenge of predominantly orthopaedic injuries for reconstructive and rehabilitation services.

Aim To develop a militarily relevant complex extremity wounding model. Study Design Controlled laboratory study with New Zealand White Rabbits. Method Phase One: Injury Development. Under general anaesthesia, the flexor carpi ulnaris of the right forelimb was exposed and high energy, short duration impact delivered via drop test rig. Anaesthesia was maintained for three hours, the animal was recovered and saline soaked gauze and supportive bandaging applied. 48 hrs later, the animal was culled and muscle harvested for histological analysis. Analgesia was administered daily, animals checked by experienced staff at least twice daily and temperatures recorded by subcutaneous transponder. Phase Two: Contamination. Sequential groups of animals had inoculums of 1×102, 1×106 and 1×108/100μl of Staphylococcus aureus administered to the muscle immediately after injury. Animals were recovered as phase one. At 48 hours, animals were culled, muscle harvested and axillary lymph nodes sampled. Quantitative microbiological analysis was performed on the muscle. Results: Six animals given a loading of 0.5kg yielded consistent injury with 20% of the muscle becoming necrotic. Representative of injury from ballistic trauma, this was adopted as standard. Twenty-two subsequent animals were exposed to the injury and inoculated with the challenge doses. 1×106/100μl S.aureus provided the greatest consistency in recovered yield. There were no adverse effects on animal welfare and body temperatures were always within normal limits. Discussion. This model enables a consistent, contaminated soft tissue injury to be delivered in vivo. It will allow the investigation of complex wound management including wound coverage and fracture fixation.