A broken kneecap occurs when the small round bone (patella) that sits over the front of your knee joint breaks.
Sometimes when a broken kneecap occurs, the patellar or quadriceps tendon can also tear. The patella and quadriceps tendon connects the big muscle in the front of your thigh to your knee joint.
What to Expect
If you do not need surgery:
- You may have only to limit, not stop, your activity if you have a very minor fracture.
- More likely, your knee will be placed in a cast or removable brace for 4 to 6 weeks, and you will have to limit your activity.
Your health care provider will also treat any skin wounds you may have from your knee injury.
If you have a severe fracture, or if your tendon is torn, you may need surgery to repair or replace your kneecap.
Sit with your knee raised at least 4 times a day. This will help reduce swelling and muscle atrophy.
Ice your knee. Make an ice pack by putting ice cubes in a plastic bag and wrapping a cloth around it.
- For the first day of injury, apply the ice pack every hour for 10 to 15 minutes.
- After the first day, ice the area every 3 to 4 hours for 2 or 3 days or until the pain goes away.
Pain medicines such as acetaminophen, ibuprofen (Advil, Motrin, and others), or naproxen (Aleve, Naprosyn, and others) may help ease pain and swelling.
- Be sure to take these only as directed. Carefully read the warnings on the label before you take them.
- Talk with your provider before using these medicines if you have heart disease, high blood pressure, kidney disease, liver disease, or have had stomach ulcers or internal bleeding in the past.
If you have a removable splint, you will need to wear it at all times, except as instructed by your provider.
- Your provider may ask you not to place any weight on your injured leg for up to 1 week or longer. Please check with your provider to find out how long you need to keep weight off your injured leg.
- After that, you can begin placing weight on your leg, as long as it is not painful. You will need to use the splint on the knee. You may also need to use crutches or a cane for balance.
- When you are wearing your splint or brace, you can begin straight-leg raises and ankle range-of-motion exercises.
After your splint or brace is removed, you will begin:
- Knee range-of-motion exercises
- Exercises to strengthen the muscles around your knee
You may be able to return to work:
- A week after your injury if your job involves mostly sitting
- At least 12 weeks after your splint or cast is removed, if your job involves squatting or climbing
Return to sports activities after your provider says it is ok. This most often takes from 2 to 6 months.
- Begin with walking or freestyle swimming.
- Add sports that require jumping or making sharp cuts last.
- DO NOT do any sport or activity that increases pain.
If you have a bandage on your knee, keep it clean. Change it if it gets dirty. Use soap and water to keep your wound clean when your provider says you can.
If you have stitches (sutures), they will be removed at around 2 weeks. DO NOT take baths, swim, or soak your knee in any way until your provider says it is ok.
You will need to see your provider every 2 to 3 weeks during your recovery. Your provider will check to see how your fracture is healing.
When to Call the Doctor
Call your health care provider if you have:
- Increased swelling
- Severe or increased pain
- Changes in skin color around or below your knee
- Signs of wound infection, such as redness, swelling, drainage that smells bad, or a fever
Eiff MP, Hatch R. Patellar, tibial, and fibular fractures. In: Eiff MP, Hatch R, eds. Fracture Management for Primary Care, Updated Edition. 3rd ed. Philadelphia, PA: Elsevier Saunders; 2018:chap 12.
Safran MR, Zachazewski J, Stone DA. Patellar fracture. In: Safran MR, Zachazewski J, Stone DA eds. Instructions for Sports Medicine Patients. 2nd ed. Philadelphia, PA: Elsevier Saunders; 2012:755-760.
Review Date 11/5/2018
Updated by: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.