Terrible triad of the elbow

The "Terrible Triad of the Elbow" is a complex elbow joint injury caused by severe trauma, simultaneously involving elbow dislocation, radial head fracture, and coronoid process fracture.

• Elbow dislocation: The forearm bones are displaced from their normal position relative to the humerus.
• Radial head fracture: The upper part of the radius (outer side of the elbow) is cracked or broken.
• Coronoid process fracture: The tip of the ulna that forms the hinge of the elbow joint is fractured.
• Associated injuries: Tearing or rupture of important ligaments around the joint (such as the lateral ulnar collateral ligament, radial collateral ligament).

It is called "terrible" perhaps for two reasons: it is miserable for both the patient and the doctor.

Injuries like this are usually very severe and require the patient to receive proper treatment and persevere with postoperative rehabilitation to regain mobility. Naturally, for orthopedic trauma surgeons, operating on these cases is a difficult challenge.

In the past, and even currently, many surgeons tend to temporarily pin the elbow joint and hope that after 4 to 6 weeks, once the soft tissues have stabilized, they can remove the pins and start rehabilitation. However, things are not that simple due to the complex structure of the elbow joint. Even with the assistance of an intraoperative C-arm, pinning the elbow joint back to its exact anatomical position is not always achieved accurately. On the other hand, removing the pins after 4 to 6 weeks often leads to elbow stiffness. This approach isCOMPLETELY WRONG.

Referring to the literature along with experience from operating on numerous cases, I can tentatively outline the following steps when we proceed to repair this complex injury:

1. Restore the radial head to its anatomical position. In cases where the radial head fracture is not too complex, reduction and internal fixation are straightforward. Conversely, when the radial head is comminuted, a radial head replacement is indicated. The problem is that we currently still lack the equipment for radial head replacement, so the core of the issue remains attempting to preserve the radial head. Sometimes it may not be intact as long as its relative shape is maintained to balance the force along the lateral column.
2. Reattach the origin of the lateral ligament complex to the proximal humerus.
3. If the joint is still unstable after performing the first two steps, coronoid process fixation can be performed (rarely necessary).
4. In cases of severe soft tissue injury, a transarticular external fixator can be used (few facilities are adequately equipped).
5. Joint pinning is only a last resort if the above three steps fail, typically encountered in open fractures, severe soft tissue injuries, or a lack of surgical instruments.

Appropriate surgical approaches are selected. Usually, I use the lateral approach first to perform the first two steps.

Below is a specific example of a terrible triad case, the patient is the mother of a medical staff member whom I operated on 1 year ago. Currently, she has recovered well and has almost no restriction in elbow movement.

In this case, fortunately, the radial head fracture was not too complex, but there were still 2 free fragments that I fixed with screws. The dislocated elbow joint was reduced and the lateral ligament was reattached to its footprint. After intraoperative clinical and C-arm examination, the elbow joint was quite stable and had good mobility.

In some delayed cases presenting after several weeks or months, restoring the radial head and reducing the elbow joint encounter many difficulties. A wider surgical approach and triceps lengthening are necessary.

Dr. Do Vu Anh

References:

1. https://surgeryreference.aofoundation.org/orthopedic-trauma/adult-trauma/proximal-forearm/fracture-dislocation-radial-head-and-or-coronoid-terrible-triad/open-reduction-internal-fixation#introduction
2. Xavier Ohl, Renaud Siboni, Surgical treatment of terrible triad of the elbow, Orthopaedics & Traumatology: Surgery & Research, Volume 107, Issue 1, Supplement, 2021, 102784, ISSN 1877-0568.https://doi.org/10.1016/j.otsr.2020.102784