Car Accident Elbow Injuries

Elbow Anatomy

Three bones come together at the elbow. The humerus is the bone in the upper arm, and two forearm bones, the radius and the ulna, form the lower part of the elbow.

Bending occurs through a hinge joint that allows the elbow to bend and straighten, called flexion and extension. Rotation occurs through a ball-and-socket joint that allows the hand to be rotated palm up and palm down, called supination and pronation. Injuries and dislocations to the elbow can affect either of these motions, so an arm can bend normally and still turn poorly.

Strong collateral ligaments on the inner and outer sides of the elbow hold the joint together and work to prevent dislocation: the lateral collateral ligament on the outside and the medial collateral ligament on the inside. The muscles that cross the elbow joint also contribute to its stability.

Nerves share the same small space. Three major nerves cross the elbow joint, which is why the doctor checks the nerve supply to the hand after a dislocation, since if nerves have been injured, some or all of the hand may be numb and not able to move.

Dislocation and Subluxation

When the joint surfaces of the elbow’s three bones are separated, the elbow is dislocated. Elbow dislocations can be complete or partial, and a partial dislocation is also called a subluxation.

Elbow dislocations usually occur after a trauma, such as a fall or a car accident. They typically follow a fall onto an outstretched hand, but elbow dislocations can also happen in a car accident when a passenger reaches forward to brace for impact. The braced arm is what carries the force into the joint: any time force is sent through the arm, the elbow can dislocate.

A simple dislocation does not have any major bone injury but has ligament injuries, while a complex dislocation has bone injuries in addition to the ligament injuries of a simple dislocation.

At the severe end, the blood vessels and nerves that travel across the elbow may be injured, and if this happens, there is a risk of losing the arm. For that reason an elbow dislocation should be considered an emergency injury.

Bones That Break at the Elbow

Three structures account for most elbow fractures, and each behaves differently.

The olecranon is the bony tip of the elbow and part of the ulna. It is positioned directly under the skin of the elbow, without much protection from muscles or other soft tissues, so it can break from a direct blow to the elbow from something hard, like a dashboard or car door in a car accident. In most olecranon fractures, the pieces of bone move out of place when the injury occurs, and for many patients with these fractures, surgery is recommended.

The radial head is the knobby end of the radius where it meets the elbow. Radial head fractures are common injuries, occurring in about 20 percent of all acute elbow injuries, and many elbow dislocations also involve fractures of the radial head. The most common symptoms include pain on the outside of the elbow, swelling, and difficulty bending or straightening the elbow or turning the forearm.

The distal humerus is the lower end of the upper arm bone, the spool around which the forearm bends and straightens. Many of these fractures are caused by a high-energy event, such as receiving a direct blow to the elbow in a car accident, and distal humerus fractures are uncommon, accounting for just about 2 percent of all adult fractures. In older adults, a distal humerus fracture is a serious injury with an uncertain prognosis.

One category sits outside the rest. In an open fracture, bone fragments stick out through the skin or a wound penetrates down to the bone, and because the skin is broken, infection in both the wound and the bone is more likely. Immediate treatment is required to prevent infection.

Ligament Instability and the Terrible Triad

A dislocated elbow that goes back into place is not necessarily a healed elbow. Elbow instability is a sense of looseness in the elbow joint that may cause the joint to catch, pop, or slide out of place during certain arm movements, and it most often occurs as the result of an injury, typically an elbow dislocation.

There are three common patterns. Posterolateral rotatory instability, from injury to the lateral collateral ligament complex, is the most common type of recurrent elbow instability. Valgus instability is due to an injury of the medial collateral ligament, and varus posteromedial rotatory instability involves the lateral collateral ligament complex together with a fracture of the coronoid portion of the ulna.

Ligaments do not show on a plain film: X-rays cannot show soft tissues like ligaments, but they can be useful in identifying fractures, dislocations, or subtle changes in elbow alignment. Many cases of elbow instability can be diagnosed based solely on a medical history and physical examination results, which makes the description of symptoms part of the evidence. In many cases, patients feel instability when pushing up from a seated position.

Nerve and Tendon Damage

Nerves and tendons add problems of their own. In some cases the ulnar nerve may be injured at the same time the fracture occurs, which can result in weakness and numbness in the ring and small fingers.

Compression of the ulnar nerve at the elbow is called cubital tunnel syndrome, the second most common upper extremity compressive neuropathy. Nonsurgical treatment aiming to decrease both compression and traction on the ulnar nerve is successful in most patients with mild nerve dysfunction.

The distal biceps tendon attaches the biceps muscle to the radius. Tears of the distal biceps tendon are uncommon, occurring in only 3 to 5 people per 100,000 each year, and rarely in women. Injuries usually occur when the elbow is forced straight against resistance, and there is often a pop at the elbow when the tendon ruptures. Other symptoms include swelling in the front of the elbow, visible bruising in the elbow and forearm, and weakness in twisting the forearm from palm down to palm up.

Timing matters for this tendon. Surgery to repair the tendon is ideally performed during the first 2 to 3 weeks after injury, because after this time the tendon and biceps muscle begin to scar and shorten. Beyond 3 weeks, it becomes more common and necessary to reconstruct the tendon with a donor tendon.

Three injuries that occur together have their own name. The terrible triad of the elbow is an elbow dislocation, a radial head fracture, and a coronoid process fracture occurring together, and the stabilizing structures in the elbow typically fail from lateral to medial through a posterolateral rotatory force after a fall onto an outstretched upper extremity.

Treatment usually involves several structures rather than one. Surgery is often needed to repair the lateral ligamentous complex, replace or fix the radial head, possibly repair the anterior capsule or fix the coronoid, and consider medial repair or application of a fixator. In some challenging cases persistent instability, complications, and loss of function may occur, and rehabilitation focuses on achieving early range of motion to prevent stiffness, which can be common after these injuries.

The pattern is identified by putting three findings together, and any one of them read alone understates the injury.

Diagnosis and Imaging

The examination comes before the imaging, and it looks at more than the bone. The doctor examines the arm for tenderness, swelling, and deformity, evaluates the skin and circulation including the pulses at the wrist, and checks the nerve supply to the hand. If the artery is injured at the time of dislocation, the hand will be cool to the touch and may have a white or purple hue, a finding made by hand and not by X-ray.

An X-ray is necessary to determine if there is a bone injury, and if bone detail is difficult to identify on an X-ray, the doctor may order a CT scan. An MRI can show the ligaments, but it is rarely required at the time of the dislocation; ultrasound can show tears in ligaments, muscles, or tendons.

A first film can understate a fracture. For a minor radial head break, the fracture may not be visible on X-rays taken at the time of the injury, but it can usually be seen if the X-ray is taken a few weeks after the injury. That is why follow-up imaging belongs in the record, and why radiology records carry weight in an injury case.

How an MRI report is read covers the language radiologists use when ligaments and tendons are the question.

Treatment and Recovery

What was injured decides what treatment does, and motion is how recovery is measured. Simple elbow dislocations are treated by keeping the elbow immobile in a splint or sling for 1 to 3 weeks, followed by range of motion exercises. If the elbow is kept immobile for a long time, the ability to move the elbow fully may be affected, and some people will never be able to fully extend the arm, even after physical therapy, although the elbow can work very well without full range of motion.

Complex injuries are different. Often a complex elbow dislocation needs surgery to restore bone alignment, and over time there is an increased risk for arthritis in the elbow joint if the alignment of the bones is not good, the elbow does not move and rotate normally, or the elbow continues to dislocate.

For fractures, open reduction and internal fixation is the procedure most often used to treat olecranon fractures, and it is also the procedure most often used for distal humerus fractures, with the fragments held by plates and screws on the surface of the bone. Elbow stiffness is one of the most common problems after any fracture around the elbow, and in most cases the injured elbow will be permanently a bit stiffer than it was before the injury.

For an olecranon fracture, most patients return to normal activities within about 4 months, although full healing can take more than a year, and for a distal humerus fracture, within about 6 months, although full healing can take up to 2 years. Recovering strength and mobility often takes longer than might be expected, sometimes up to 12 months or more.

For instability that needs an operation, with a commitment to rehabilitation, patients may regain full range of motion by 6 to 10 weeks after surgery, and most return to full activities by 6 to 12 months after surgery.

Records for Car Accident Elbow Injuries

An elbow case is unusually good at showing function, because the records fit together. The first examination note is where circulation and nerve findings are captured or lost. The imaging shows the position of the bones, and the operative note names the structures that were repaired, which for a complex injury is a list rather than a single item.

Therapy records show range of motion over time, which is the closest thing an elbow case has to a measurement of recovery, and patient descriptions of catching, popping, or giving way document an instability that no single image shows. A long wait between the first visit and follow-up care leaves a gap in treatment that an insurer can point to.

An elbow injury can sit alongside a shoulder injury or a wrist injury on the same side, and each needs its own examination and imaging.