Knee Injury

You use your knees all the time, whether you realize it or not. Your knees help lower you when you sit or lie down. They help you lift your body from a sitting position. And every time you walk or change direction, you use your knees to push off.

When you injure your knees, you may experience pain every time you move. The pain and range of motion limits could disable you from both work and home activities. Even if you work a desk job, an injured knee could prevent you from sitting and working comfortably.

Your Knee Anatomy and Functions

Your Knee Anatomy and Functions

Your knee joint brings together four bones. The femur, or thigh bone, is the longest and strongest in your body. The tibia and fibula sit in your lower leg. The tibia bears your weight in your calf. The fibula does not bear weight. Instead, it stabilizes your leg by attaching to the tibia below your knee and the top of your ankle. The fourth bone, the patella, protects the knee.

Ligaments hold bones together at joints. Your knee has four internal ligaments plus a ligament to hold the patella in place. 

The ligaments inside your knee include:

  • Lateral collateral ligament (LCL)
  • Medial collateral ligament (MCL)
  • Anterior cruciate ligament (ACL)
  • Posterior cruciate ligament (PCL)

The ACL and PCL cross inside your knee, hence the name “cruciate.” At your knee, the femur has two knobs called condyles. The ACL attaches the outside condyle of the femur to the front of the tibia. The PCL attaches the inside condyle of the femur to the rear of the tibia. Together, these ligaments guide the pivoting of the knee. They also prevent knee rotation.

The MCL attaches the surface of the inside condyle to the surface of the tibia. The LCL attaches the surface of the outside condyle to the top of the fibula, making it the only knee ligament to connect to this bone. The patellar ligament, sometimes mistakenly called the patellar tendon, holds the kneecap to the tibia over the joint.

Cartilage lines your knee. This tough, smooth connective tissue protects the bones from grinding against each other. They also allow the bones to pivot smoothly. Finally, they cushion the bones when you walk, run, or jump.

Articular cartilage lines the surfaces of the femur and tibia. Meniscus cartilage sits like a cushion between the femur and tibia.

How Do Knee Injuries Happen?

Knee injuries can happen in four primary ways, including:


Hyperextension is one of the most common ways of injuring your knee. Hyperextension happens when your knee bends too far or in the wrong direction. Since the ligaments guide and limit knee movement, they must stretch or tear when you hyperextend your knee.

Hyperextension injuries often happen in slip and fall accidents. As you lose your footing, you begin to fall. When you try to catch yourself, the momentum of your body can cause your knee to bend the wrong way and hyperextend it.


As you use your knee, it develops small imperfections. Microscopic cracks and tears are common effects of normal use. When you rest, these cracks and tears heal. But when you expose your knees to repetitive stresses, the cracks and tears do not heal. Instead, they grow into injuries.

Overuse injuries do not happen in accidents. Instead, they require wear and tear over time. Often, they occur in workplaces where your knees get subjected to repetitive stresses caused by standing, walking, lifting, and climbing. When they happen on the job, you can seek workers’ compensation benefits.

You can also suffer overuse injuries while you recover from an accident. Suppose that you broke your leg in a motorcycle accident. While you have a cast on your broken leg, you will put additional stress on your healthy leg. This stress can cause an overuse injury in your healthy knee.

Blunt Force

Blunt force on your knee can injure it. A force can cause your knee to bend the wrong way. But even when a blunt force does not hyperextend your knee, it can still injure it. A blunt force can fracture the bones of the knee. It can also stress the cartilage and cause it to tear.

Blunt-force knee injuries can happen in falls. They can also happen in car accidents. You could hit your knee on the underside of the dashboard during a collision. A side-impact crash could also cause the door to collapse and crush your knee.

Penetrating Object

Penetrating injuries happen when an object pierces your knee. These injuries can occur when you fall on a construction site onto a sharp object like a nail. They can also happen when something gets driven into your knee. For example, the sharp edge of a license plate frame could cut into your knee in a pedestrian accident.

What Are Some Common Traumatic Knee Injuries?

Knee injuries can take many forms depending on the structures that get damaged. Some common knee injuries include:

Knee Sprain

Knee sprains happen when the ligaments hyperextend. The ligaments stretch and may even tear. You might hear or feel a popping in your knee as they do so. 

A knee sprain can cause symptoms such as:

  • Knee pain and inflammation
  • Limited range of knee motion
  • Bruises

A mild sprain will heal in four to six weeks. A severe sprain happens when your knee ligaments partially or fully tear. This injury might require surgery and up to a year of rehabilitation.

Torn Knee Cartilage

Blunt, penetrating, and hyperextension injuries can tear your knee cartilage. Without your knee cartilage, your bones grind against each other. 

This can produce symptoms such as:

  • Pain
  • Swelling
  • Stiffness
  • Clicking or hitching in the knee

Cartilage heals very slowly. As a result, you might need to rest your knee for several months before the symptoms begin to go away. You may also need surgery if your knee has any loose pieces of cartilage floating inside.

Fractured Patella

A blunt impact on your knee can fracture the patella. A fractured patella can produce pain and swelling.

Doctors can reconstruct your kneecap using screws and plates. If the kneecap shatters into three or more pieces, doctors may remove rather than repair it.

How Can I Get Compensation For a Knee Injury?

You can pursue compensation for knee injuries that resulted from someone else’s actions. To recover compensation for the injury, you must prove that the other person either intentionally or negligently injured you. Once you prove liability, you can seek compensation for your medical expenses, income losses, and pain and suffering.

A knee injury can disable you from working or even driving, shopping, or caring for your children. Call Zavodnick & Lasky Personal Injury Lawyers at (215) 875-7030 or contact us online to learn about your right to compensation under Pennsylvania law and how we can help.