How do combat injuries impact bone health in the ADVANCE cohort? The most recent ADVANCE publication found that changes in bone health in those with combat-related trauma injury appear to be local to injury rather than widespread throughout the body.
Many lower limb amputees have low bone mineral density, but not much is known about bone health in those with combat injury. Having low bone mineral density increases risk of fracture. But does combat-related traumatic injury result in lower bone mineral density in the ADVANCE cohort? Along with answering this question, we also wanted to test whether traumatic lower limb amputees have reduced localised bone mineral density on their amputated side, or whether this reduction was widespread across the skeleton.
We found that:
- Bone mineral density of the hip was lower in the injured compared to the uninjured group. However, this reduction in bone mineral density was significant only at the hip of the amputated limb of amputees, but not on the other (unamputated) side.
- The reduction in bone mineral density was greater for those with an above knee amputation compared to those with a below knee amputation.
- There were no differences in bone mineral density of the spine between those with an amputation and the uninjured.
- Those who suffered an amputation were no less active than those who were uninjured. This is important as lower activity levels are linked to reduced bone mineral density. This shows that the reduction in bone mineral density on the amputated side was not due to reduced activity levels.
Our findings indicate that changes in bone health in those with combat-related trauma injury appear to be local to injury rather than widespread and are only evident in those with lower limb amputations. This may be because of altered loading to the joint and muscle, creating a reduced mechanical signal to the hip on the amputated side, resulting in localised reductions in bone mineral density. But what can be done to mitigate reduced bone mineral density? Interventions to stimulate bone, such as certain exercise interventions, may be helpful. Some of the ADVANCE researchers have already begun a series of studies to investigate whether certain exercise programmes may be effective at reversing this reduction in localised bone mineral density. This work aims to reduce lifetime fracture risk in those who have experienced a lower limb amputation.