Navigating the journey of parenting a newborn can be quite the adventure, often filled with a variety of amusing questions that might seem odd to others. If you find yourself pondering whether your baby has kneecaps, rest assured, you’re in good company. Many parents turn to the internet with the query “Do babies have kneecaps?” as they share in their confusion.
Babies possess kneecaps composed of cartilage, which will ossify into bone from the ages of 2 to 6.
Indeed, the situation is both yes and no. Babies come into the world with cartilage segments that will, over time, form the bony kneecaps, or patellae, seen in adults.
Similar to bone, cartilage provides necessary structure in the body, found in areas like the nose, ears, and joints. However, cartilage is softer and more pliable than bone.
The inquiry is logical upon reflection. Babies’ knees, like the rest of their bodies, are flexible and not as solid as those of older children, leading many parents to ponder the nature of their infants’ delicate knees.
Thus, the questions arise: Do babies possess kneecaps? At what point do their knees solidify? Are the knees of infants more susceptible to injury? What additional information should parents have regarding the knees of their babies? Experts weigh in on these matters.
Do Babies Have Kneecaps at Birth?
Experts confirm that babies are indeed born with kneecaps; however, the confusion among parents is understandable. The kneecaps of newborns are made of cartilage, which is not as hard as the bony kneecaps seen in older children and adults.
“It’s a widespread belief that babies are ‘born without kneecaps,'” states Adoyen Aireys, MD, medical director at Optimale and former emergency department physician. “However, this is incorrect. Babies do have kneecaps, which are composed entirely of cartilage, hence the term ‘cartilage patellae,’ which means cartilage kneecaps.”
It’s not that babies lack kneecaps; rather, their kneecaps are composed of a material that differs from that of older children and adults, which is more suitable for their stage of development.
Dr. Aireys describes cartilage as a supple, cushioning material that safeguards joints against friction. Considering the range of activities infants engage in, it’s logical they would gain from having softer, more pliant kneecaps. “Softer bones facilitate a smoother passage through the birth canal, and pliable knees support the crawling and toddling that mark our earliest years,” notes Dr. Aireys.
Why aren’t babies born with bony kneecaps?
Babies born with bony kneecaps could complicate the birthing process and increase the risk of birth injuries due to the rigidity of bone. Unlike bone, cartilage is more flexible and less prone to breaking under pressure.
Cartilaginous kneecaps are better suited to withstand the developmental transitions of crawling and walking in children.
When does the kneecap turn into bone?
Babies possess significantly more cartilage in their skeletons compared to adults. Dr. Eric Edmonds from Rady Children’s Hospital states that the ossification process — the transformation of cartilage into bone — in most children’s kneecaps starts between the ages of 2 and 6. This gradual process spans several years.
It’s common for multiple cartilage pieces to ossify simultaneously, eventually merging into a single bone.
This ossification progresses throughout childhood. By the time children reach 10 to 12 years of age, their kneecaps are typically fully ossified. A small part of the original cartilage remains, along with a section of fatty tissue known as the fat pad.
When Do Babies’ Kneecaps Become Firmer?
Eventually, everyone develops firmer kneecaps, also known as patellae. The transformation of the patellae from cartilage to bone, known as ossification, typically concludes by the time a child starts elementary school.
“The kneecaps begin to ossify between the ages of two and six,” states Pierre Mini Poinset, MD, a board-certified pediatrician and medical advisor at AAP. “The process starts slowly from the middle of the kneecaps and moves outwards toward the edges.”
The knee joint is designed for flexibility, involving cartilage in its function. The connection between the femur (thigh bone) and the patella (kneecap) is cushioned by articular cartilage, which facilitates smooth movement between the knee and leg and safeguards against injuries.
Can anything go wrong?
Children are at a heightened risk for complications or injuries during the development of the kneecap due to the knee joint’s complexity and the significant stress it endures.
Some potential issues include:
- Bipartite patella, which occurs when the cartilage areas that are transforming into bone do not merge into a single bone. The two distinct bone pieces might be symptom-free or may cause pain in a child.
- Osgood-Schlatter disease, a tendon injury that can affect the bone and result in a painful bump below the kneecap, often found in young athletes.
- Tendon or ligament injuries, such as those to the ACL or MCL adjacent to the kneecap, can become strained or torn, placing extra stress on the kneecap.
- A torn meniscus, which is a piece of cartilage in the knee joint that, when torn, can lead to pain and issues with movement.
What about an adult’s kneecap?
The kneecap, a small, semi-circular bone, sits in the quadriceps tendon and covers the knee joint. It protects the tendons and ligaments of the knee joint and helps with its movement. The knee joint plays a crucial role in facilitating most physical activities.
The kneecap is surrounded by ligaments, tendons, and bits of cartilage that help cushion the joint’s movement.
The knee joint is a major weight-bearing joint in the body. According to Harvard Health, every extra pound of body weight puts four times the pressure on your knees.
Potential Issues With Kneecap Development
While it might appear that a baby’s kneecaps are more delicate and sensitive compared to those of an older child, there’s no need for worry. Dr. Poinsett confirms that babies’ kneecaps are actually less susceptible to injury or health issues than those of older children.
It’s important to note that a baby’s kneecaps are composed of soft, flexible cartilage by design. This explains why they can crawl about without injury and curl up into adorable little bundles as newborns.
During the transition from infant knees to adult knees, potential issues may arise, Dr. Aireys explains. One such issue is bipartite patella, a condition that may occur in your growing child. “The kneecap is made up of different pieces that usually come together and fuse over time. Bipartite patella happens when these pieces do not fully fuse, leading to a ‘split’ kneecap,” Dr. Aireys states.
This condition might resolve naturally or may require physiotherapy management. “It’s important to keep an eye on your child for knee pain and swelling. These symptoms could be a sign of a knee issue like arthritis or damage to the tendons or ligaments,” he notes.
Common Knee Injuries in Children
Children, particularly those active in sports, often sustain injuries. However, the injuries typically do not involve the kneecaps.
“Kids usually get knee pain from twisting or hurting the ligaments around the knee,” Dr. Poinsett says. “It’s not very common for them to hurt their kneecap.”
Knee injuries can still occur in children. The most frequent types of knee injuries are caused by overuse, abrupt twisting, or direct blows to the knee and its surrounding joints. Common knee injuries in children include:
- Injuries to the articular cartilage
- Tears of the anterior cruciate ligament
- Tears of the meniscal cartilage
- Patellofemoral stress syndrome
How can you keep your knees healthy?
To enhance your knee health and prevent injuries, consider the following methods:
- Muscle strengthening. Performing exercises that target your hamstrings, quadriceps, hips, and core can contribute to a stable and robust knee joint.
- Low-impact exercise. Engaging in activities like cycling, swimming, and using an elliptical machine, which do not exert weight on the knees or involve high impact, can help safeguard your knees from additional stress.
- Range-of-motion exercises. These exercises can assist in increasing the mobility of your knee joint.
When To Call the Doctor
Indicators that your child might have sustained a knee injury include:
- Stiffness or difficulty in moving the leg or bending the knee
- Swelling in or around the knee area
Should your child exhibit any of these signs, or if you suspect they have incurred a knee injury, it is crucial to seek medical advice immediately.
In Last
Babies are born with a cartilaginous structure in their knee joint, which develops during the embryonic stage. Indeed, babies have kneecaps composed of cartilage. Over time, these cartilaginous kneecaps ossify into the bony kneecaps adults possess.