#1 Epiphyseal Plate — Growth Plate Functions
While all bones undergo bone widening only certain bones primarily those of the appendages undergo interstitial lengthening the process of bone lengthening takes place at the epiphyseal plate.
The epiphyseal plate consists of four distinct zones the zone of resting cartilage consists of hyaline cartilage and is anchored to the epiphysis.
The zone of proliferating cartilage organizes a supply of highly mitotic chondrocytes as these cells divide and increase in number the resting cartilage is pushed outward helping to lengthen the diaphysis in the zone of hypertrophic cartilage chondrocytes mature and enlarge this maturation.
It also helps to expand lacunae and lengthen the diathesis the thin zone of calcified cartilage is only a few cells thick and consists of older and dying chondrocytes the cartilage matrix near these cells is calcified osteoclasts.
It breaks down the calcified cartilage paving the way for osteoblasts from the diathesis to deposit new bony matrix proliferation of chondrocytes increases cell number the proliferation results in moving the epiphysis away from the diathesis.
This increases the length of a bone the larger amount of dying cartilage tissue is replaced with bone matrix solidifying the resulting elongation.
This process of bone elongation continues until the epiphysial plate closes when cartilage cells in the plate stop proliferating bone replaces the cartilage leaving an epiphyseal line when this happens adult stature is achieved.
Epiphyseal Plate Fracture
What is in a sealed epiphyseal plate fracture? Epiphyseal is just another word for growth plates.
So, growth plates are the areas of cartilage located near the ends of bones they are only found in long bones, not like sesamoid or flat bones each long bone has at least two growth plates.
One on each end and the growth plate itself is located between the metathesis and epiphysis growth occurs at each end of the bone around the growth plates and growth plates are the weakest area of a child’s growing skeleton.
And this is because growth plates are the last part of the bone to ossify so when a child is fully grown the rough plate hardens into solid bone.
However, because the growth plate is the last part of the bone to ossify growth plates are especially susceptible to fracture there are five different types of appendiceal plate fractures type 1 is a breakthrough the bone at the growth plate (epiphyseal plate) separating the bone end from the bone shaft.
And completely disrupting the growth plate type 2 is like an extension of type 1 it’s similar and that it is a breakthrough in the bone at the growth plate.
However, with type 2 the crack goes through the bone shaft as well and this is the most common type of growth plate fracture type 3 the fracture crosses through a portion of the growth plate(epiphyseal plate) and breaks off a piece of the bone end.
This is more common in older children type 4 is a breakthrough the bone shaft the growth plate and the end of the bone and type 5 is a crushing injury to the growth plate from a compression force in these type 5 are very rare who is most susceptible to this fracture.
Because the growth plate is the weakest point of a child’s growing skeleton injuries freaking to happen in children and adolescents an injury that would cause a sprain in an adult is more likely to cause a bone fracture in a child just because the child’s bone is much more fragile than an adult’s and as many as one-third of all childhood fractures are growth plate injuries.
And growth plate or epiphyseal plate injuries are twice as likely to occur in boys and girls and one of the reasons for this is because girls bodies mature earlier than boys bodies so their growth plates are replaced by stronger bone at an earlier age than boys bones would be how do you growth plate fractures occur growth plate fractures.
Most often occur as item four in long bones of the body as opposed to like sesamoid or flat bones the most common ones being femur tibia and fibula radius sometimes ankle or foot bones and phalanges and most growth plate injuries and children result from a fall usually a while running or playing competitive sports such as football, basketball, baseball, softball track in gymnastics.
And also in competitive sports, a lot of the repetitive movements in sports like gymnastics or baseball can cause growth leg injuries too just from the constant pounding on the bones may cause epiphyseal plate injuries and then also recreational activities such as biking sledding skiing skateboarding and rollerblading.
Okay now that you know how you get this fracture how do you recognize the epiphyseal plate first?
Color figure depicting a pediatric lower limb, AP view, from the pelvis to the toes, showing the growth plates in the femur, fibula, and tibia.
It’ll be persistent pain that will not diminish after a few days and it may get worse if this condition was undiagnosed may be an inability to move the joint due to pain and epiphyseal plate injuries often occurring in youth.
Here is that this injury is not always as obvious as a fracture so it’s important to keep the possibility of an official plate fracture in mind if a skeletally immature patient is presenting with these symptoms.
There may be the presence of an intelligent gait this is limping and it’s only if the injury is to the lower limb obviously it may be possible limb length differences and be a presence of a visible deformity long-term consequences there may be chronic pain over the fracture site after healing.
Osteoarthritis is not uncommon later in life because these fractures are occurring typically along joint lines and can impact the structural integrity of the cartilage uneven limbs can occur because of overstimulation of healing by the limb in the epiphyseal plate.
There will be increased osteoblastic recruitment activity to the fracture site causing it to essentially overheal the site when this happens the injured limb is consequently longer than the uninjured limb if the fracture is occurring at the knee it’s not uncommon for the patient to have follow-up visits until they are skeletally immature.
But if it occurs elsewhere it’s standard for the patient to have follow-up visits for up to a year after the injury as mentioned on the last slide uneven limbs can occur here you can see if a child’s knee is fractured.
The visible plate (epiphyseal plate) will heal as if it were a fracture on any other part of the bone a site that was the fracture and most formally a gap formed by the growth plate will now be filled with a bony bridge if this occurs on one side of the bone then you’ll end up with a closed growth plate on that side and limited growth.
While the other side continues to lengthen and mature this can cause abnormalities in bone length and overall limb structure which can result in some of the conditions of the epiphyseal plate.
Now, on to intervention strategies, there is the non-surgical side which if this fracture is treated properly in cotton time many can heal properly without surgery by simply applying a stabilizing cast and limiting participation in physical activity sometimes.
However, surgical interventions are required if this fracture is unstable the image on the right is of the reduction in internal fixation surgery which is the most commonly used surgery to fix these fractures as you can see the bone fragment has been reduced or like moved back into place and fixed there by screws.
Hence, the name however it’s not uncommon for the surgeon to splint this post-surgery well how does this fracture heal initially the inflammatory response for fruits and Zinka muscles that will differentiate into bone and cartilage producing cells.
A cartilaginous soft callus is then formed by counter blasts eventually the cartilaginous callus will be removed by osteocytes and then replaced by bone via osteoblastic activity that was previously mentioned.
Osteoblasts will form the heart callous and continue to lay a bony matrix around the fracture throughout the patient’s life eventually all the weaker spongy bone from the bony careless will be replaced by a healthy and new bone this can be demonstrated
Epiphyseal Plate and Epiphyseal Plate Injuries
Here we’re going to be looking at the epiphysial plate also known as the growth plate found on long bones and we’re also going to look at the different types of epiphysial injuries.
An example of an epiphyseal plate injury:-
There are four main types of bones you have long bones, these would be like
1. The femur or humerus bone — your femur or your humerus bones found in the arms or legs that they’re longer than they are wide.
2. Short Bones– then you have short bones short bones are defined as being approximately as wide as they are long these would be bones like your carpools or tarsals.
Originally published at https://bingeexpress.online/epiphyseal-plate-growth-plate-functions/