Gunshot injuries to the shoulder are rare and
difficult to manage. We present a case series of seven patients
who sustained a severe shoulder injury to the non-dominant side
as a result of a self-inflicted gunshot wound. We describe the injury
as ‘suicide shoulder’ caused by upward and outward movement of the
gun barrel as the trigger is pulled. All patients were male, with
a mean age of 32 years (21 to 48). All were treated at the time
of injury with initial repeated debridement, and within four weeks
either by hemiarthroplasty (four patients) or arthrodesis (three patients).
The hemiarthroplasty failed in one patient after 20 years due to
infection and an arthrodesis was attempted, which also failed due
to infection. Overall follow-up was for a mean of 26 months (12
to 44). All four hemiarthroplasty implants were removed with no
feasible reconstruction ultimately possible, resulting in a poor functional
outcome and no return to work. In contrast, all three primary arthrodeses
eventually united, with two patients requiring revision plating
and grafting. These patients returned to work with a good functional
outcome. We recommend arthrodesis rather than replacement as the
treatment of choice for this challenging injury. Cite this article:
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
Crown copyright 2009. Published with the (permission of the Defence Science and Technology Laboratory on behalf of the Controller of HMSO. Introduction. The optimum strategy for the care of war wounds is yet to be established. A need exists to model complex extremity injury, allowing investigation of wound management options. Aim. To develop a model of militarily relevant extremity wounding. Study Design. Laboratory study with New Zealand White Rabbits. Methods. Phase 1. Development of injury. Following induction of general anaesthesia, a muscle belly on the flexor aspect of the forelimb of the rabbit was exposed. This was achieved by creating a fascial tunnel under the belly of flexor carpi ulnaris (FCU). Utilising a custom built drop test rig a high energy, short duration impact was delivered. To replicate casualty evacuation timelines, the animal was maintained under anaesthesia for three hours and recovered. The wound was dressed with saline soaked gauze and supportive bandaging. 48 hrs later, the animal was culled and the muscle harvested for histological analysis. Analgesia was administered once a day. Animals were checked by experienced staff at least twice a day and body temperature recorded by a subcutaneous transponder. Phase 2. Contamination of muscle injury. Sequential animals had inoculums of 1×102/100μl, 1×106/100μl and 1×108/100μl of Staphylococcus aureus administered to the muscle immediately after injury. Animals were recovered from anaesthetic and monitored as per phase 1. Delivery was evaluated by droplet spread and via injection by fine bore needle into the muscle belly. At the 48 hour point, the animals were culled, dressings removed, the muscle harvested and auxiliary lymph nodes sampled. Quantitative microbiological analysis was performed to determine colony forming unit counts (CFU) at 24 hours post-collection. Results. Phase 1. Six animals were exposed to a loading of 0.5kg. Histological analysis demonstrated a consistent injury pattern with 20% of the muscle belly becoming necrotic. Following discussion with subject matter experts this was found to be representative of the nature of injury from ballistic limb trauma and was adopted as standard. Phase 2. Twenty-two animals were exposed to the standardised injury and then inoculated at the prescribed challenge doses and delivery methods. A challenge dose of 1×106/100μl S. aureus delivered by droplet provided the greatest consistency. A group of six animals with an average challenge dose of 3.3×106/100μl yielded growth at 48hrs on average of 9.2×106 CFU. There were no adverse effects on animal welfare throughout, with body temperatures within normal limits at all times. Discussion. The use of rabbits in the investigation of musculoskeletal injury and infection is well established. No study to date however has addressed high energy complex soft tissue wounding, contamination and its optimum management. Considering the current burden of such wounds the need for this question to be answered in a research setting is transparent. This model enables a significant, reproducible, contaminated soft tissue injury to be delivered in vivo. It will allow the investigation of
