Knee Injuries and Disorders
The knee is extremely important, as it allows you to walk, run, jump, go up and down stairs, and perform many activities of daily living! Its complexity also makes it vulnerable to injuries and degenerative conditions. For athletes, active people, and those experiencing age-related changes, knowing the most common problems that can occur and how to treat them are important.
Anatomy of the Knee
The knee is, in essence, a hinge joint that connects the thigh bone (femur) to the shin bone (tibia). It also includes the kneecap (patella) and a smaller bone, known as the fibula, which is attached to the outer side of the joint. Numerous essential components collaborate together, in order for the knee to provide stability and flexibility. Articular cartilage, a slick tissue that coats the ends of the femur and tibia, enables the bones to slide freely when you move. Between these bones are two c-shaped pieces of cartilage called the menisci, cushioning and distributing weight evenly over the joint. Tough bands of tissue called ligaments help hold the bones together. The anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL) control movement forward and backward whereas the medial collateral ligament (MCL) and lateral collateral ligament (LCL) prevent sideways instability. Tendons like the quadriceps and the patellar tendons attach muscles to bones, allowing us to extend our legs. Synovial fluid also bathes the joint, lubricating it to reduce friction and providing nutrients to its cartilaginous surface. Damage to any of these structures, from body injury or simply wear, can disrupt knee function. This can result in pain, swelling, or trouble moving.
Common Knee Injuries and Conditions
Knee injuries and conditions are commonly due to trauma, overuse, or degeneration associated with aging.
- Ligament Injuries
Ligament injuries like ACL tears are prevalent in sports like soccer or basketball, in which sudden stops or pivots put stress on the joint. This is especially common in women due to differences in the strength and alignment of muscles; which makes them particularly susceptible to these types of injuries. There are approximately 200,000 ACL tears per year in the U.S., and female athletes are 2–8 times more likely to incur such injuries compared with male athletes [1].
- Meniscus Tears
Meniscus tears happen when the knee twists during weight lifting and sports activities, although older adults can also have degenerative tears as cartilage wears down over the years. Each year, the U.S. sees more than 850,000 operations treating meniscal injuries [2].
- Tendon Injuries
Tendon injuries, like patellar tendinitis (also known as “jumper’s knee”), are caused by repetitive stress on the tendon below the kneecap, and are particularly common in athletes who perform a lot of jumping or running.
- Arthritis
Arthritis is a common cause of chronic knee pain. The most common form, osteoarthritis, occurs as cartilage deteriorates with aging, causing stiffness and pain. Rheumatoid arthritis is an autoimmune disease that causes inflammation in the membrane lining the joints, damaging cartilage and bone. Fractures or ligament injuries can lead to post-traumatic arthritis. More than 32.5 million adults in the United States have osteoarthritis, and the knee is one of the joints most commonly affected [3].
- Other Conditions
Patellofemoral pain syndrome (runner’s knee), which causes aching around the kneecap, is the result of overuse or muscle imbalances. Bursitis inflammation of the fluid-filled sacs that cushion the joint is commonly the result of prolonged kneeling. Iliotibial band syndrome (ITBS), a common overuse injury in runners, occurs when the IT band rubs over the outer part of your knee, causing sharp pain. Adolescents might develop Osgood-Schlatter Disease, when growth spurts irritate the tendon below the kneecap. Broken bones or dislocated joints, though less common, need to be treated urgently and often occur after high-impact trauma such as falls or car crashes.
Preventing Knee Injuries
Preventing knee injuries is all about strength training, flexibility, and establishing good habits.
- Strengthening Muscles
Building up the muscles around the knee most importantly, the quadriceps, hamstrings, and glutes brings stability and helps absorb shock when a person moves. Exercises such as squats, lunges, and leg presses are particularly effective, but even basic activities such as chair stands can build strength.
- Improving Flexibility
Stretching is just as vital. Tightness in muscles in the calves, hamstrings, or IT band can tug on the knee joint, elevating injury risk. Yoga or pilates helps with stretching, flexibility, and balance, leading to less strain during exercise.
- Warming Up and Cooling Down
When we warm up before exercising, we warm the knee up for the task at hand. Light jogging, cycling or dynamic stretches, such as leg swings, increase blood flow to the muscles and joints preventing stiffness.
- Wearing Proper Footwear
The key to picking supportive footwear is to find what works best for each activity. Cushioned running shoes, or orthotics for flat feet helps prevent misalignment and unnecessary stress.
- Avoiding Overuse
The key to avoiding overuse is to let exercise intensity build over time so that the body adapts without the knee being overwhelmed. For instance, novice runners should gradually build distance, alternating with walking.
- Maintaining a Healthy Weight
Another important component is weight maintenance. Extra weight multiplies pressure on the knees. Losing even just 10 pounds can reduce stress on the joints by 40 pounds when walking and doing other daily activities [4].
- Using Proper Technique
Proper form in sports and lifting is also important. Landing softly with bent knees after a jump, or lifting heavy things with the legs (not the back) helps protect the knees.
- Protective Gear
Protective equipment, whether knee braces or pads, provide additional support for high-risk activities.
Treatments for Orthopedic Knee Conditions
Non-Surgical Treatments
For mild to moderate problems, non-invasive methods usually work. Rest, ice, compression, and elevation (R.I.C.E) are recommended for swelling and pain in injuries like sprains. Physical therapy is key to recovery, as therapists provide individualized exercises to build back strength and mobility. For example, step-ups or resistance band workouts stabilize the joint, while water aerobics does so with low-impact conditioning. NSAIDs (e.g., ibuprofen) control pain and inflammation; corticosteroid injections provide temporary relief for arthritis flare-ups. Injections of hyaluronic acid, which mimic the knee’s natural lubricating fluid, can relieve stiffness for months at a time. Finally, platelet-rich plasma (PRP) therapy, in which concentrated growth factors are separated from the blood of the patient and injected into the site of an injury, also promotes healing in a damaged tendon or early-stage arthritis.
Surgical Treatments
Surgery becomes necessary when conservative treatments fail. Arthroscopy, a minimally invasive operation, repairs torn menisci, removes loose cartilage or repairs damaged ligaments by inserting instruments through small incisions. Most people recover within weeks. ACL reconstruction involves substituting torn ligaments with grafts taken from the patient’s own tendons or a donor. In cases of severe arthritis, partial or total knee replacement removes damaged bone and cartilage. It then replaces them with durable metal or plastic implants.
Emerging Therapies
New treatments like stem cell injections use the body’s own healing power. For instance, stem cells sourced from fat or bone marrow are injected into the knee to lower inflammation and promote cartilage and vascular repair. Though still experimental, early research has shown promise in slowing arthritis progression. Researchers are also investigating customized 3D-printed implants that fit a patient’s anatomy, and gene therapies aimed at lowering inflammation or stimulating cartilage growth.
Rehabilitation
Rehabilitating knee injuries or recovering from surgery takes time and dedication. Physical therapy starts with gentle movements to help prevent stiffness and progresses to real strength-building exercises, like leg presses and balance drills. Gentler activities, such as swimming and cycling, mitigate strain on the joint. A well-balanced diet full of anti-inflammatory foods and nutrients such as calcium and vitamin D can enhance the health of bones and tissue.
Keeping knees healthy is essential to leading an active, independent life. Our goal at the Orthopedic and Sports Medicine Institute (OSMI) is to provide our patients quality, cutting-edge orthopedic treatments, both surgical and non-surgical. If you have questions or concerns about knee pain please submit an online appointment request or contact our office at 817-529-1900.