Musculoskeletal Trauma

Bone basics & blood loss

Bone is living, vascular tissue. It stores minerals, produces red blood cells (RBCs), and bleeds when it is broken, even when the fracture is closed. The periosteum, the membrane that covers the bone, contains its own vessels and nerves; if bone fragments are visible on exposed periosteum, never remove them.

The blood loss from a "simple" closed fracture is easy to underestimate. A tibia-fibula fracture bleeds about 1 pint (500 cc), a femur fracture about 2 pints (1,000 cc), and a pelvic fracture about 3–4 pints (1,500–2,000 cc) or more. The traction splint was invented specifically to reduce the blood loss from a fractured femur.

The four types of musculoskeletal injury

Musculoskeletal injuries fall into four types, distinguished by which structure is damaged. The table below defines each of them.

Table 32.1The four types of musculoskeletal injury

You do not need to diagnose which of the four you are looking at in the field. Any extremity with pain, swelling or deformity is treated as a fracture and splinted.

Compartment syndrome & the six Ps

Compartment syndrome begins with a fracture or crush injury that causes bleeding and swelling within a muscle compartment. As the compartment fills, the pressure inside it rises until it exceeds the perfusion pressure of the tissue, and cellular damage follows. If the pressure is not relieved, the limb may be lost. The signs are pain, swelling, a sensation of pressure, and an extremity that feels hard compared with the uninjured side.

The six Ps summarize the findings of a compromised extremity: Pain or tenderness, Pallor, Paresthesia, Pulses that are diminished or absent, Paralysis, and Pressure.

Splinting — core principles

A splint immobilizes the bone ends and the joints adjacent to the injury. Doing so reduces pain, prevents further damage to soft tissue, nerves and vessels, prevents a closed fracture from becoming an open one, and minimizes blood loss.

Realignment is generally reserved for angulated long-bone shafts. Joints are splinted in the position in which they are found, with one exception: if the extremity distal to the joint is cyanotic or pulseless, attempt gentle traction to bring it to a neutral position. The order of care is fixed. Life threats come first. Then expose the injury site, assess circulation, sensation and motor function (CSM) before and after splinting, and immobilize the injury site and the adjacent joints, letting the speed of the work match the patient's priority.

The single most serious splinting hazard is "splinting someone to death": delaying the transport of an unstable patient in order to perfect a splint.

Traction splints & pelvic injuries

Traction splints are femur-specific devices. Every field traction splint uses "counter-traction" anchored against the pelvis rather than true independent traction. The indication is a painful, swollen or deformed mid-thigh with no injury to a joint or to the lower leg. The splint is contraindicated when there is an injury to the pelvis, hip or knee, an avulsion or partial amputation, or an injury to the lower third of the leg.

A pelvic injury is handled with minimal movement: move the patient as a unit, and never lift with the pelvis unsupported. A pelvic wrap is made from a sheet about 10 in wide, placed at the level of the greater trochanters and tied firmly without overcompression. Apply it for pelvic deformity or instability, and also for a high-risk mechanism of injury (MOI) even when no deformity is obvious.

Knee, tibia/fibula & ankle/foot injuries

A true knee dislocation, in which the tibia is displaced relative to the femur, can compress the popliteal artery and cut off the blood supply to the lower leg. An absent distal pulse in this setting is a true emergency, and gentle repositioning may be needed to restore the pulse. A patellar dislocation, in which the kneecap is displaced laterally, is a different injury and is less urgent.

A tibia or fibula fracture is splinted with a vacuum or air-inflated splint, and manual traction is maintained while the splint is applied. Sprains and fractures of the ankle and foot are both common and hard to tell apart, so either is treated as a fracture. Use a soft or pillow splint, or a commercial splint that extends above the knee.