Babies do have kneecaps, but these are not bony yet and are made of a soft rubbery material called cartilage. According to a post by Dr. Edward Gotlied, a pediatric specialist in the Stone Mountain area, Georgia, newborns have kneecaps, also known as the patella. They usually form at about the fourth month of fetal life but do not show up in X-rays as they are not solid bones yet and are made of cartilaginous material (1) Cartilage is not radio opaque.
Why do babies have cartilaginous kneecaps? When do they become bony, and can any issues crop up during this process? Read this post as we answer these questions and give you a few tips to strengthen your baby’s kneecaps.
Why Don’t Babies Have Kneecaps?
A newborn has more bones than an adult due to the presence of more flexible cartilage in the body. As the baby grows, some of the cartilage hardens and turns to bone, and some bones fuse together (2).
Babies have cartilage in place of bones during birth to benefit both the mother and the baby. Bones are more rigid and harder than cartilage. Cartilage keeps the baby flexible, so it can easily pass through the birth canal. So, if a newborn has bone kneecaps, they might break during birth or injure the birth canal at the time of delivery.
Also, as cartilage is softer and more flexible than bones, it helps the baby be more flexible while exploring and finding their way in the world by crawling or walking.
At What Age Does The Kneecap Turn Into A Bone?
According to Dr. Eric W. Edmonds of the Rady Children’s Hospital, the cartilaginous patella starts to ossify (turn into bone) between the ages of two and six years. Various parts of cartilage gradually harden to form a bone, and multiple sections of the bone fuse to form the kneecap (3)
The ossification of cartilage is a slow process and might continue until puberty. The underside of the patella continues to have a layer of cartilage, which works as a cushion for the bones. So in case of any injury or pressure on the knee, it can bear the pressure. It also helps them withstand compression due to weight and prevent friction with the adjacent bones (4).
Sometimes, during the process of kneecap formation, some children might develop problems or experience injuries due to the complexity of the patella’s structure and the amount of load it bears.
Possible Complications During The Kneecap Development
It is important to observe your baby’s limbs during the kneecap development process. There is a chance for them to develop one or more of the problems mentioned below.
- Bipartite patella: It means patella with two parts. It is a condition wherein the bone centers within the cartilage do not fuse, leading to a two-part kneecap. It is usually asymptomatic and might get carried to adolescence. However, babies might occasionally experience pain when subjected to direct trauma, overuse, or strenuous activity.
The condition can be managed by restricting strenuous activities, administering nonsteroidal anti-inflammatory drugs, etc. If these fail to relieve the pain, surgery might be required (5).
- Congenital dislocation of the patella: It manifests immediately after birth and may cause permanent dislocation of the kneecap. The symptoms include a bend in the joints that cannot be straightened, knock knees, external tibial torsion, and foot deformity.
When detected early on, this condition can be treated with surgery(6).
The following complications are mostly found in children and teens, and are rarely encountered in babies.
- Osgood-Schlatter disease: This condition is more common in adolescents than in babies. It usually shows up during the growth spurts when the bones, muscles, and tendons change rapidly. Children who participate in athletics and sports are at a higher risk of developing this condition. It is a temporary condition and rarely requires surgery.
The area below the knee where the tendon from the kneecap attaches to the tibia becomes inflamed, causing knee pain and swelling. The doctor may recommend rest, over-the-counter medications to relieve pain, icing, and stretching exercises (7).
- Injuries: Sometimes, due to excess stress or overuse of the joint, children might experience pain in the knees. This could be due to the wear and tear of the tendons and ligaments associated with the kneecaps.
- Torn meniscus: The meniscus is a C-shaped piece of rubbery cartilage between the tibia and the thigh bone. When children are subjected to rigorous physical activities, or trauma it might result in a torn meniscus. The symptoms include a popping sensation in the knee, stiffness, swelling, pain while rotating the knee, and tenderness of the knee joint.
It can be managed by using crutches to restrict the joint’s movement, exercising to strengthen the muscle around the knee, and wearing special shoe inserts to distribute the weight uniformly while walking, so that there is no excessive pressure (8)
Kneecaps help your baby learn to crawl or walk. Read the next section to understand how to take care of your baby’s kneecaps.
How To Care For Your Baby’s Kneecaps?
Here are some easy ways to strengthen your baby’s kneecaps and protect them from injuries.
- Anecdotal evidence suggests that regular massage of the knees with olive oil or coconut oil might strengthen the kneecaps.
- You can also try a few stretching exercises, such as bending the knee in and out and moving the legs up and down. These also help in strengthening the knees.
- The cartilage inside the knees provides a cushiony effect while the baby tries to crawl on hard surfaces. It might look painful to us, but it is not the case for babies. However, if your baby tends to crawl on hard surfaces often, you can provide them with knee protectors to prevent bruising.
Babies are born with kneecaps, but they are made of cartilage, which hardens to form bony kneecaps with time. While your baby’s body does its magic, you can provide your baby with calcium and nutrient-rich food to help develop healthy and strong bones.
2. What Makes Children’s Bones Different From Adult Bones? Childen’s Healthcare Of Atlanta
3. Dr. Eric W. Edmonds; Bones Develop in Distinctive Ways Depending on Gender; Rady Children’s Hospital-San Diego
4. Arnold I. Caplan; Cartilage; Scientific American (1984).
5. Chandra M. Jennings and Lindsay Tjiattas-Saleski; Bipartite Patella; The Journal of the American Osteopathic Association (2016).
6. Akifusa Wada, et al.; Congenital dislocation of the patella; NCBI
7. Osgood-Schlatter Disease (Knee Pain); American Academy of Orthopedic Surgeons
8. Torn Meniscus; Boston Children’s Hospital