H. Salter-Harris VI Fracture (Rang Type VI): These injuries are less common and are caused by a direct blow to the growth plate and its soft tissue covering (periosteum, perichondral ring). The degree of trauma and area of injury can dictate whether a subsequent growth plate closure will or will not occur.
Patients will typically have swelling and tenderness at the site of injury and on the other side of the bone where the growth plate extends. Weightbearing may be difficult.
X-rays may be initially negative only to find a growth plate closure at a later time.
The most important component in evaluating these injuries is a thorough history and physical examination. Even if x-rays are negative, clinical suspicion of these injuries is a must and further evaluation and treatment should begin. MRIs may be necessary to fully evaluate these injuries when x-rays are negative. If there is a small tilt to the lower end of the bone, a very gentle closed reduction may be necessary followed by a period of nonweightbearing in a below-the-knee cast. Follow up x-rays and CT scans may be needed to identify the possibilities of a premature growth plate closure. If angular deformities start to develop after injuries, cast wedging can be performed to help the bone grow more correctly as it heals. If after healing there is a small degree of misalignment, small bone cuts with wedges (osteotomies) will be helpful to provide great long-term care for the joint. This will help to realign the joint.
I. Transitional Fractures (Triplane, Tillaux): Transitional fractures occur when the bone growth is slowing and going into a full maturation process. It is the period of time when the growth plate is going from a child to adult. Twisting injuries are most often the cause and soccer is the most common sport we see in children with these fractures.
Triplane Pre and Post
CT scans show stepoff and displacement better. Also the intra-malleolar nature of the fracture can be visualized.
Postop with percutaneous Screw Fixation
Preop and Postop Xrays of ORIF Triplane Distal Tibia Fracture with FIbula Fracture
Signs and symptoms include:
- Pain, swelling and difficulty weightbearing due to the nature of the injury.
- Possible deformity of the ankle (looks out of place).
- Pain weightbearing with swelling diffuse over the fractured area.
X-rays are necessary and usually show the degree of injury to the lower tibia and growth plate. CT scans are often necessary to evaluate the degree of displacement of the fracture that goes into the ankle joint. The fracture line usually goes into the joint (triplane, Tillaux) and in some cases up the back of the bone (triplane). Because these fractures occur during a transition period of child to adult, growth plates are usually closing and little growth is expected to the tibia in the future. Premature physeal closure is not as significant and if present it is usually minimal (less than ¼”).
- The more critical problem with these fractures is the need to address portion of the bone that goes into the ankle joint. That fracture may be nondisplaced or grossly displaced. If displacement is present, closed reduction and percutaneous pinning with or without an arthroscopy may be beneficial if the displacement is mild. If grossly out of line, an open reduction internal fixation may be needed to provide the exact anatomic reduction of the joint, thus minimizing the later risk of osteoarthritis.
- Postoperatively patients are placed in a cast either above or below the knee for 2-4 weeks followed by casting for 4-6 weeks below the knee. Most of this period of time is nonweightbearing.
- If anatomical reduction (normal position of bones and growth plates) is achieved, then an excellent long-term prognosis is expected. The fracture that goes up the back of the bone is typically not an issue. The issue is more of the fracture that goes into the joint. If this joint is aligned properly and the bone is reduced into its anatomical position, long-term consequences are rare.
Pre and postop triplane fracture.
Intramalleolar Triplane Fracture Preop and Postop Percutaneous Fixation (Below)
What is a Premature Physeal Closure (PPC)?
PPCs can occur with injuries to any growth plate. Higher energy traumas may make a growth plate more prone to a premature closure. The earlier the age of injury, the greater the risk. Some of the reasons for a premature physeal closure include:
- Severe trauma to the tibia at the moment of injury may be the inciting factor for a PPC.
- Repeated attempts at closed reduction to get anatomic alignment.
- Delay in treatment for the closed reduction.
- Hardware across the growth plate erroneously placed may cause permanent damage to the growth plate. Less common with pins and more common with screws.
- Open fractures.
- Displaced, unreduced fractures with a fracture gap that may be filled with soft tissue. The larger the gap both initially and after treatment, the greater the risk.
What do Premature Physeal Closures Cause?
- Bone growth ceases on part or all of the growth plate. If one side of the growth plate closes, the other side grows causing an angular growth to the bone and often the joint. This means that the joint is crooked and weightbearing is affected. Later arthritis is common.
- The bone could cease growing and a shortened bone can develop leading to a limb length discrepancy (one leg longer than the other).
How are Premature Physeal Closures Treated?
Treatment depends on the age of the patient (the younger the patient the worse the prognosis), bone involved and how much of the growth plate has been affected.
If small and on the periphery (the outside portion of the growth plate), the bone that caused the growth plate closure can be excised and replaced with fat or other agents. If large and affecting a large area of the growth plate, it should also be left alone until full bone maturity. Depending on many factors, the other extremity may need to be addressed by doing a procedure to stop its growth as well. In other cases after the bone affected fully matures, the bone can be lengthened to equal in length to the unaffected side.