Knee Fracture 101: Types, Symptoms, Treatment, and Surgery

Maybe you took a hard fall on icy pavement, landing directly on your kneecaps and outstretched hands, or perhaps you were playing tackle football when another player’s helmet collided with the front of your leg. Either way, now your knee is swollen, bruised, and it’s painful or impossible to bend it or put weight on it.

What you may be dealing with is a knee fracture, the most common of which is a kneecap or patella fracture, says Moin Salah, M.D., MBA, a board-certified sports medicine specialist and the medical director of clinical operations at Commons Clinic. And when it comes to knee injuries, this one is an emergency, he says, meaning you should see a doctor right away for diagnosis and treatment, which may or may not include surgery, depending on the type of fracture and how severe it is.

This type of injury takes time to heal, but a full recovery is often possible with the right treatment and rehabilitation plan. Consider this your guide to knee fractures, including their causes, symptoms, and prevention, and learn what surgery and recovery might look like.

Definition of a Knee Fracture

A knee fracture happens when one or more of the bones in or around the knee breaks. For clarity, a “fracture” and a break are the same thing. Most commonly, this break happens in the patella, or kneecap, which is the small bone that covers and protects the knee.

When a fracture occurs close to the knee joint—in the nearby femur (thigh bone), tibia (shin bone), or fibula (calf bone)—it’s considered a knee fracture as well. The same goes for a Segond fracture, which typically happens when the ACL tears and a small piece of knee bone chips off.

Segond fractures are much less common than kneecap fractures, so in this article, we’ll focus on the causes, treatment, and surgical options for patella fractures.

Anatomy and Function of the Knee Joint

The knee joint, the body’s largest joint, acts like a hinge to flex and extend the leg—movements crucial for walking, running, jumping, and kicking.

The knee connects the upper and lower legs. The femur (thigh bone) sits above the joint, while the tibia (shin bone) lies below, with their corresponding muscles. Four knee ligaments, including the ACL, connect these bones, while tendons join the leg muscles to the patella, or kneecap. The kneecap shields the joint, and beneath it lies articular cartilage, which cushions and smooths knee movement. “The cartilage resembles the white shiny material on a chicken wing bone,” Dr. Salah adds.

The fibula (calf bone) runs parallel to the tibia. Though not directly part of the knee joint, it helps provide stability.

Types of Knee Fractures

“Patella fractures range from nondisplaced, incomplete fractures requiring nonsurgical management with a brace, crutches and physical therapy, to displaced and comminuted fractures needing surgical fixation and extensive rehabilitation to regain knee function,” says Bonnie Gregory, M.D., sports medicine specialist and assistant professor of orthopedic surgery at McGovern Medical School at UTHealth Houston.

Here are the different types of knee fractures:

• Stable fracture: Also called a nondisplaced fracture, this simplest type occurs when broken bones stay aligned. Though surgery isn’t usually needed, it requires doctor monitoring and rehabilitation.
• Displaced fracture: In this break, patella pieces shift out of alignment. Surgery is typically needed for proper healing.
• Comminuted fracture: The knee bone shatters into three or more pieces, usually from severe trauma like a car crash. Treatment varies by case and can be stable or displaced.
• Transverse fracture: The kneecap breaks horizontally into two pieces, which may become displaced.
• Open fracture: Broken bones pierce the skin, creating an open wound. These fractures often damage other knee parts, take longer to heal, and risk infection. Emergency medical care is essential.

Regardless of the type, all knee fractures require proper medical evaluation and treatment. The severity of the break, along with factors like age and activity level, helps determine the best treatment approach. Quick medical attention improves the chances of optimal healing and return to normal activities.

Causes and Risk Factors

A patella fracture typically results from direct trauma to the kneecap. Most commonly, this trauma occurs during:

• Falls on hard surfaces
• High-impact sports like rugby, football or soccer
• Car accidents when knees slam into dashboards

Less often, patella fractures result from indirect trauma. A sudden quadriceps contraction (muscles on the front of the thigh) can jerk the tendon attached to the patella, breaking the bone.

A May 2022 study in the European Journal of Trauma and Emergency Surgery examined more than 3,000 patella fractures in adults. It found 70% were caused by falling from standing height.

The median patient age was 67, and nearly two-thirds were women. Another study of more than 150,000 patella fractures, published January 2023 in BMC Musculoskeletal Disorders, found women were about 1.5 times more likely than men to sustain the injury.

Women are more likely to develop osteoporosis, a risk factor for bone fractures including knee fractures, Dr. Gregory says. Osteoporosis weakens bones, making them more brittle. Women typically have smaller, less dense bones than men and lose more bone mass after menopause.

Women are also more likely to develop rheumatoid arthritis (RA), another risk factor for knee fractures, according to a September 2017 meta-analysis in Medicine. RA causes bone loss and joint damage, weakening bones around the knee joint.

Adolescents also risk knee fractures, Dr. Salah says, because their leg growth plates remain open. These cartilage areas allow bones to grow but are weaker than surrounding ligaments and tendons. Young athletes in high-impact sports face particular risk.

Symptoms and Diagnosis

A knee fracture usually causes immediate, obvious symptoms, Dr. Salah says. Signs include:

• Sharp knee pain
• Immediate swelling that worsens or persists
• Difficulty walking or bearing weight
• Bruising
• Inability to straighten the leg

“If you’ve had trauma to the knee or kneecap and you feel pain, have swelling, and have trouble weight-bearing, it makes sense to get evaluated formally right away,” Dr. Salah says.

To diagnose the injury, a doctor will ask about the cause, perform a physical exam, and take an X-ray. These steps help determine the fracture type and best treatment course, including whether surgery is needed.

For knee injury diagnosis and treatment, Commons Clinic offers expert physicians who provide knee fracture treatment and surgery.

Surgical Procedures

Some patella fractures heal without surgery when they’re simple breaks with aligned bone pieces. In these cases, a knee cast or brace and avoiding weight-bearing can heal the injury.

Unstable fractures with misaligned bones usually require surgery. Open fractures need immediate surgery due to infection risk. For closed fractures where skin remains intact, doctors may delay surgery until nearby scrapes heal.

The type of displaced fracture determines the surgical approach:

• Comminuted fracture: When the kneecap breaks into multiple displaced pieces, surgeons remove fragments too small to fix and reconnect remaining pieces with wires and screws. Severe cases may require complete patella removal.
• Transverse fracture: For horizontal breaks with displaced pieces, surgeons use screws, pins, plates, or combinations of these. Some cases require a “figure-of-eight” band to unite the pieces.

During surgery, doctors also repair any damage to knee joint ligaments or soft tissue. Most kneecap surgeries last one to two hours, with patients receiving general or spinal anesthesia. After surgery, doctors apply a cast, splint or brace to immobilize the knee while it heals.

Rehabilitation and Recovery

Recovery from a knee fracture takes three to six months, with or without surgery. The healing process requires patience, consistent rehabilitation work, and careful adherence to medical guidance. Though each patient’s timeline varies, most can return to normal daily activities within six months.

“The initial treatment and rehabilitation focuses on keeping the knee in a fixed position, not letting it bend at all,” Dr. Salah says. “Usually a person wears a knee immobilizer, a long, solid, stiff brace that locks it in place. You’ll need to avoid weight-bearing on the leg, using crutches, a scooter or a wheelchair.”

He says patients should take anti-inflammatory medicine like ibuprofen for pain and swelling, with additional pain relievers if needed, while elevating and icing the knee.

“As the knee heals, we move to an adjustable knee brace allowing some range of motion and start gentle weight-bearing, like putting a toe or heel down with a crutch,” Dr. Salah says. “As it feels better, we’ll wean from two crutches to one, then none.”

All patients work with a physical therapist during recovery. The therapist provides exercises to strengthen the leg as the knee heals, helping restore normal function.

“The quadriceps in the thigh notoriously weaken with knee injuries, so you’ll need to focus on strengthening them through physical therapy and at-home exercises,” Dr. Salah says.

Following the rehabilitation plan closely improves outcomes and helps prevent future knee problems. Most patients can resume low-impact activities after full recovery, though some may need to modify high-impact sports. Regular exercise and maintaining a healthy weight help protect the healed knee long-term.

Complications and Prevention

A kneecap fracture can lead to several complications that may affect long-term knee function and mobility. Early treatment and proper rehabilitation improve outcomes, though some patients experience lasting effects. The severity of these complications often depends on the initial injury and how well patients follow their treatment plan.

• Knee arthritis: “Any type of trauma to the knee can cause arthritis, leading to pain and stiffness,” Dr. Salah says. “The back surface of the kneecap contains articular cartilage, which cushions the joint and allows smooth knee movement. Direct trauma to the kneecap can compress that cartilage, potentially causing arthritis.” A June 2020 study in the British Journal of Sports Medicine found knee injuries like fractures in young adults increased their future arthritis risk sixfold.
• Loss of mobility: Chronic stiffness may limit knee bending and extending, Dr. Gregory says.
• Muscle weakness: Some patients never fully regain quadriceps strength.
• Chronic knee pain: Pain may persist long after initial healing.

Early evaluation and treatment offer the best chance to prevent these complications, Dr. Salah says. Patients should follow their doctor’s treatment and recovery plan, including physical therapy.

Some patients need physical therapy for up to a year to restore normal or near-normal function, Dr. Gregory says. She adds that kneeling often remains uncomfortable, requiring modifications to activities like yoga or prayer to prevent reinjury.

Despite these potential complications, most patients who follow their treatment plan achieve good outcomes. Regular monitoring by medical professionals helps identify and address problems early. With proper care and patience, many people return to their normal activities, though some may need permanent modifications to protect their knee.

Managing Osteoporosis and Underlying Conditions

Osteoporosis and rheumatoid arthritis increase knee fracture risk, especially with age. Dr. Gregory says patients with either condition should discuss medication or supplement options with their doctor. Doctors often prescribe bisphosphonate medications to slow bone loss in osteoporosis patients and may recommend calcium and vitamin D supplements.

Reducing fall risk is crucial. “When we combine fall risk with weakening bone, it sends fracture risk through the roof,” Dr. Gregory says.

People 65 and older face higher fall risks. Prevention methods include:

• Safe walking spaces: Keep floors clear and carpets secure. Avoid area rugs that can bunch up. Outdoors, watch for slippery or uneven surfaces.
• Assistive devices: Hold handrails on stairs. Consider using a cane or walker for stability if needed.
• Regular exercise: Build strength through activities like yoga, Pilates and weightlifting to strengthen bones and muscles and slow osteoporosis-related bone loss.
• Vision and hearing checks: Update prescriptions regularly. Ensure glasses and hearing aids fit properly, as sensory changes increase fall risk.
• Proper footwear: Choose comfortable, low-heeled shoes with nonslip soles.
• Adequate sleep: Fatigue increases fall risk.
• Moderate alcohol use: Excessive drinking affects balance and raises fall risk.

Managing underlying conditions while taking preventive measures significantly reduces fracture risk. Patients should work with their medical team to develop a comprehensive prevention plan that fits their lifestyle and needs. Regular monitoring helps ensure the effectiveness of these strategies over time.

Frequently Asked Questions (FAQs)

What does a knee fracture feel like? “Anyone with a possible knee fracture will be in significant pain,” Dr. Salah says. “The pain feels sharp. Walking becomes difficult or impossible, swelling appears immediately and persists, and patients can’t bend the leg or put weight on it.”

Can a fractured knee heal without surgery? Yes, a simple, stable knee fracture where broken pieces remain aligned can heal without surgery, but requires proper treatment. Patients need a knee cast or brace to immobilize the joint and prevent bone separation. Weight-bearing increases gradually during healing.

What treatments exist for knee fractures? Treatment varies by fracture type. Simple, stable fractures need a knee cast or brace and crutches or a scooter to avoid weight-bearing. Complicated or displaced fractures often require surgery, followed by immobilization. All patients need physical therapy to regain strength and mobility.

How do you treat a fractured knee at home? A Commons orthopedic specialist should oversee treatment. At home, patients can follow their treatment plan by taking anti-inflammatory medicine like ibuprofen, elevating the knee, and applying ice packs.

Can you walk on a fractured knee? Doctors advise against walking on a fractured knee before medical evaluation. During healing, patients gradually bear weight using a knee immobilizer or cast, often with mobility aids like wheelchairs, scooters or crutches.

Conclusion

If you’ve fractured your knee, the best thing you can do is see a doctor as soon as possible to be evaluated and start treatment. Connect with an orthopedic specialist at Commons Clinic who can guide you through the treatment process, including surgery if necessary, and help create a recovery plan that will get you back on your feet.

Following your treatment and rehab regimen closely is your best bet for avoiding potential complications from a knee fracture. With patience and time, you can regain the strength and mobility to get back to your normal activities.

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