You have been diagnosed with a patellar fracture?
This means that your kneecap is broken. Regardless of the treatment you receive, it will take a few weeks for your kneecap to fully heal.
Here are the answers to the questions you are probably asking yourself about the treatment, rehabilitation, recovery time, walking, and potential complications of a patellar fracture.
To answer these questions, I rely on:
- my 11 years of experience as a physical therapist in a traumatology surgery department, rehabilitation center, and private practice (in 🇫🇷);
- extensive research and reading of international medical literature on the management of patellar fractures.
Feel free to leave any additional questions in the comments, and I will be happy to answer them!
Last update: May 2023
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Written by Nelly Darbois, physical therapist and scientific writer
What are the different types of patellar fractures?
Did you know that only 1% of all human fractures involve the patella, commonly known as the kneecap? It’s the most common knee fracture.
They often occur due to a fall or car accident with a bent knee, especially in people between 20 and 50 years old, and more frequently in women than men.
Treatment for a kneecap fracture in elderly patients (over 65 years old) is similar to that of younger patients.
A kneecap fracture is usually easily noticeable with symptoms such as:
- Severe pain in the knee area
- Swelling and bruising around the kneecap
- Difficulty walking, bending or straightening the knee
While an X-ray can confirm the diagnosis, it can also determine the type of fracture. A kneecap fracture can have various characteristics:
- Non-displaced (bone fragments are in close proximity or touching) or displaced (bone fragments are separated by more than 2 mm)
- Vertical (=longitudinal) or transverse: bone is broken in two in both cases; transverse fractures are more common
- Comminuted, shattered kneecap: bone is broken into more than two fragments
- Less frequently, star-shaped, osteochondral, avulsion fracture (=patella sleeve fracture) or apical
- Open or closed
- Hairline knee cap fracture
- Cracked kneecap / chipped patella
- Inferior pole patella fracture
- Fracture + dislocation or subluxation of the kneecap
Regardless of the type of kneecap fracture, the general approach to treatment is the same. The medical and paramedical team will personalize the treatment according to the type of fracture, your health status, and your medical history.
What is the treatment for a non-displaced patellar fracture (non-surgical)?
Usually, a non-displaced patella fracture will not require surgery and can be treated conservatively. With proper medical and paramedical supervision, the knee will heal without the need for surgery.
Fractured knee cap treatment without surgery consist of:
- immobilization of the knee,
- rehabilitation exercises / physical therapy,
- and a gradual return to normal activities.
Brace for fractured kneecap?
Can you bend and straighten the knee immediately after a non-surgical patella fracture? This is a relevant question, and your doctor should provide you with recommendations.
However, there is no real consensus, and there are no comparative studies that allow us to say with great certainty whether the knee should be immobilized or bent.
So, what should you do?
Generally, a brace will be prescribed to keep the knee straight or slightly bent (10°). Some teams will tell you to wear the brace 24/7 for 10 days, while others will say to wear it for 4 to 6 weeks. Others will tell you to remove the brace during physical therapy and at night. Some will even say that you don’t need a brace at all!
It’s challenging to give a general recommendation on this matter. It really depends on your lifestyle habits, the season (these warm and enclosing braces are much more bearable in winter than in summer at 40°), your pain, and your apprehension about not healing or becoming stiff.
Talk to your doctor or physical therapist about it. Weigh the pros and cons of wearing the brace more or less in your situation. Generally, there are more cons than pros.
As a general rule, the people I take care of wear the brace for the first few days during movements but remove it at night and when sitting or lying down. Then they abandon it completely and gradually after a few days, at most 3 or 4 weeks.
Sometimes people may not be prescribed a brace. If there is no pain or discomfort (while resting, standing, or walking), everything is fine, and no brace is necessary in this case.
Bending and extending the knee after kneecap fracture
Once you remove the brace from time to time or permanently, an important question arises: what should you do with your leg? Is it better to leave it bent or straight?
The patella heales better when the leg is straight, as the muscle (the quadriceps) that attaches to it pulls slightly on the patella when the knee is bent. Therefore, it is generally recommended to:
- Keep the leg straight frequently, but not all the time to prevent stiffness.
- Not exceed 90° of knee flexion (leg vertical to the thigh) for 4 to 6 weeks.
Finding the right balance for you is one of the main challenges of physical therapy.
The knee should be kept straight often and can be bent without forcing it up to 90° for 4 to 6 weeks after patellar fracture.
Weight-bearing after kneecap fracture
Weight-bearing on the fractured leg is also subject to different recommendations. Usually, weight-bearing is allowed, and you can stand on the leg with the fractured patella and even walk.
However, you will typically need two crutches to avoid putting all your body weight on the fractured leg. Over time, you will rely less and less on the crutches until you no longer need them.
After kneecap fracture, walking with weight-bearing is possible by putting weight on the fractured leg, preferably with two crutches rather than without anything.
Rehabilitation & physical therapy for a non-surgical kneecap fracture
Physical therapy sessions are often prescribed for a non-displaced and non-operated kneecap fracture (while waiting for direct access to physiotherapy in France). These physiotherapy sessions typically take place at home or in a clinic, and sometimes even through telehealth.
The goals of these sessions are to:
- Answer any questions you may have and provide reassurance
- Help you find the right balance between rest and walking, repeated knee flexions, or continuous leg extension
- Help you eventually resume all your physical activities from before (walking without crutches, running, carrying loads, sports, driving a car, etc.)
Physiotherapy does not speed up the process of bone healing, which takes at least 4 to 6 weeks. The objective is simply to help you go through this period more calmly and be able to resume your activities as soon as possible without too much stiffness or muscle loss.
There is no minimum number of physiotherapy sessions required: some people may need only 3 to 5 sessions, while others may need 2 or 3 sessions per week for several weeks. There is no need for any special equipment such as electrotherapy, as its use will not help you recover faster.
The goal of rehabilitation after a kneecap fracture is to gradually resume your previous activities by regaining full knee flexion and extension, and sufficient strength in the quadriceps muscle (the thigh muscle).
What is the treatment for a displaced patellar fracture (surgical)?
Sometimes, the patellar fracture is too severe to heal without surgery. In this case, an operation is performed on the same day or within a few days after the accident.
Surgery: Different Techniques of Patella Fracture Fixation
There are different surgical techniques for patellar fracture. Currently, we do not have enough data to determine if certain surgical techniques are better than others (Cochrane 2021).
Each surgical team has its own habits. The team that operated on you is the best equipped to explain what they specifically did for you. You will also leave the hospital with an operative report that summarizes the operation (you will learn new vocabulary!).
Generally, the surgeon:
- reduces the fracture (puts the various pieces of bone back in the right place);
- holds the various bone fragments together;
- places metal implants to reinforce the entire structure, or use suture-based fixation.
Classically, the AO-technique for patella fixation utilizes axial K-wires in combination with anterior tension banding. Screw fixation, both with and without tension banding for reinforcement, is another option.Ka-Hon Shea et al. 2019
Transosseous sutures have been applied in conjunction with suture-based anterior figure-of-eight cerclage. Extraosseous suture fixation via circumferential cerclage in combination with anterior tension banding has also been described.
The surgery aims to realign and stabilize the various bone segments: open reduction and internal fixation.
You will probably be prescribed compression stockings or socks to reduce the risk of thrombosis (which occurs very rarely in any case).
Immobilization of the knee after surgical treatment of broken kneecap
Most often, you will be prescribed a brace to immobilize your knee with your leg straight. This is the best way for the patella to heal.
Depending on your situation, you may be instructed to:
- Wear the brace 24 hours a day for 3 to 6 weeks (remove it only to wash);
- Wear it during the day;
- Wear it only when changing position, walking, or standing;
- Wear it only if you experience pain.
There are no comparative studies that allow us to say whether wearing the brace all the time or very little is better. The more complex and unstable your fracture is, the more you will be advised to be careful, keep the brace on, and limit knee flexion.
In any case, you should limit knee flexion in the weeks following the operation. Generally, it is recommended not to exceed 90° for 3 to 6 weeks. Pain should also guide you.
Weight-bearing on the affected leg
Weight-bearing on the fractured leg is usually allowed on the same day after kneecap surgery. This means you can walk by putting your foot on the ground, depending on your pain.
You will need crutches to relieve some weight-bearing (your physiotherapist can prescribe them for you). Gradually, you will put more and more weight on your operated leg until you no longer need crutches (usually 2 to 6 weeks after the operation).
Check with someone who has access to your medical and surgical records to see if you have permission to bear weight, and if so, whether it is at 100% of your body weight or not.
Rehabilitation & physical therapy for a surgical kneecap fracture
Whether you have had surgery or not for your patellar fracture, rehabilitation is generally similar.
The goal is to support you in gradually resuming all of your previous activities, such as walking, driving, and sports.
To achieve this, your physiotherapist will help you:
- Regain good mobility in knee flexion and extension;
- Avoid stiffness in other joints;
- Regain muscle strength;
- Walk gradually without crutches.
Generally, you start physiotherapy at the hospital the day after the operation. You then continue in private practice (at home or in a clinic).
Some people only need a few sessions and then take care of themselves, occasionally checking in with their physiotherapist. Others are interested in more regular treatment, usually one to three times a week for a few weeks to a few months (in France).
Transcutaneous Electrical Nerve Stimulation (TENS) can relieve your pain in the days following the operation, but it is not essential.
There are no studies comparing the recovery of people who have had little versus a lot of physiotherapy. Discuss with your physiotherapist what is best for you!
Climbing stairs after patella fracture surgery: is it possible?
Of course, you can climb up and down stairs after a patella fracture surgery!
You just need to adjust the way you climb them.
In the beginning, keep your leg straight and climb one step at a time, with one leg after the other.
- Start with the “good leg” to go up (the non-operated one)
- Start with the “bad leg” to go down (the operated one)
Over time, you will be able to bend your leg more while putting weight on it.
After a few weeks, you will be able to climb up and down the stairs normally! It’s also a great exercise for muscle strengthening!
Can you walk after breaking your knee cap?
Yes, in most cases, you can walk immediately whether you have had surgery or not. You will probably need crutches at first to relieve pressure on your leg.
Gradually, you will put less weight on the crutches until you can walk without them.
Pain should guide you!
Most of the time, you can walk immediately despite a patella fracture or fissure.
What is the recovery time for a patellar fracture?
It is completely normal to be concerned about how long it will take to recover after kneecap fracture! Know that it is impossible to predict with certainty.
Many factors come into play:
- the type of patella fracture;
- your general health;
- your knee history;
- whether you smoke or not;
- your weight; etc.
Here are the average times I observe in the people I take care of. There is no data from medical literature.
|Stage||Recovery tyme after fractured kneecap|
|You have much less pain||2-3 weeks|
|Your bones are well healed||6-8 weeks|
|Your knee swelling disappears||Several weeks to months|
|You start walking with crutches||Immediately|
|You start walking without crutches||6 weeks – 3 months|
|You can drive a car||6 weeks-12 weeks|
|You return to work||2-4 months|
|It’s time to get back to sports!||2-6 months|
|You have fully recovered functionally and muscularly||4 months – 1 year|
Know that no physiotherapy technique can accelerate the time of bone healing: this time is incompressible.
If you smoke, you can, however, accelerate the healing time by stopping (or reducing) tobacco consumption. This will also have a positive effect on the healing of your scar if you have surgery.
Driving after a patellar fracture: when is it safe?
You will find very different opinions on the subject of resuming driving a car after a patella fracture.
In France 🇫🇷, The Highway Code does not provide any specific guidance on this matter. It is up to the driver to ensure that their condition is compatible with reactive driving.
In United-States 🇺🇲, the law changes from state to state. Some have laws about resuming driving after an accident, others do not.
If you have a strict contraindication supporting it, the use of pedals is not recommended. Even though you will put much less weight on the pedals than when walking.
Of course, you cannot drive with a Zimmer brace that keeps your leg straight if you don’t have an automatic car. And even with an automatic car, the position may be impossible or uncomfortable.
The same goes for traveling as a passenger with a Zimmer brace.
Here is an overview of a publication that summarizes the opinions given by surgeons about when to resume driving after fractures, both surgical and non-surgical, including patella fractures.
There is no specific indication for patella fractures, but more general indications on resuming driving after a non-displaced lower limb fracture requiring the use of a brace.
In this case, 60% of orthopedic surgeons surveyed say that it is safe to drive. However, it is not known what type of brace is being referred to: it is more likely to be braces that do not include the knee joint.
In general, driving is resumed in the weeks following the patella fracture once the knee can easily bend at least 90°. There are always people who resume driving much earlier!
Up next: when to drive after a fracture or surgery?
Are there any long-term effects / complications after a patellar fracture?
Keep in mind that in the vast majority of cases, people fully recover after a patella fracture. You will be able to resume all your daily activities and sports. This can take 2 months in the best-case scenario, and up to 6 months to 1 year (more rarely).
However, many people still wonder about possible complications and consequences after a patella fracture. Here are some words on the subject, even though they are the exception rather than the rule.
The following complications may occur:
- stiffness in the knee (without necessarily being bothersome for daily life ; see knee CRPS after surgery)
- infection (only in case of surgery; 0 to 5% of cases)
- knee pain
- problems with surgical material for operated fractures (0 to 22% depending on the studies)
- delayed healing, non-union of the scar (1 to 7%)
- knee osteoarthritis. 8 years after the fracture, 50% of people have osteoarthritis. However, this figure could be equally high if we did X-rays on similar people who did not have a fracture. Moreover, osteoarthritis seen on X-rays is not necessarily a sign of knee pain or problems.
Having diabetes or having had a stroke in the past increases the risk of infection or non-union. But even in this case, it remains very rare, and there are much more chances that you will not have any complications.
Sequels and complications are rare after a patella fracture.
Here’s what I wanted to tell you about this! I wish you a very good recovery! Do you have any comments or questions? Your comments are welcome 🙂 !
If you feel the need to learn more about the recovery period after a kneecap fracture, I wrote this guide in eBook format:
You may also like:
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- Hot to Treat Swollen Hot Knee?
- Recovery Time of Knee Fractures
- Knee joint pops out of place (Dislocated Kneecap)
To answer patients and internet users’ questions, I identified the most reliable and relevant scientific publications on patellar fracture by using the Medline database. The keywords used were “patellar fracture” or “patella fracture” in the title.
Out of the 175 publications identified in the last 20 years, I selected the following ones after reading their title and abstract. To access the studies, I used the excellent website and project Sci-hub.
Steinmetz S, Brügger A, Chauveau J, Chevalley F, Borens O, Thein E. Practical guidelines for the treatment of patellar fractures in adults. Swiss Med Wkly. 2020 Jan 15;150:w20165. doi: 10.4414/smw.2020.20165. PMID: 31940427.
Sayum Filho J, Lenza M, Tamaoki MJS, Matsunaga FT, Belloti JC. Interventions for treating fractures of the patella in adults. Cochrane Database of Systematic Reviews 2021, Issue 2. Art. No.: CD009651. DOI: 10.1002/14651858.CD009651.pub3.
Greenberg A, Kadar A, Drexler M, Sharfman ZT, Chechik O, Steinberg EL, Snir N. Functional outcomes after removal of hardware in patellar fracture: are we helping our patients? Arch Orthop Trauma Surg. 2018 Mar;138(3):325-330. doi: 10.1007/s00402-017-2852-2. Epub 2017 Nov 28. PMID: 29185046.
Kadar A, Sherman H, Glazer Y, Katz E, Steinberg EL. Predictors for nonunion, reoperation and infection after surgical fixation of patellar fracture. J Orthop Sci. 2015 Jan;20(1):168-73. doi: 10.1007/s00776-014-0658-4. Epub 2014 Oct 13. PMID: 25308213.
Petrie J, Sassoon A, Langford J. Complications of patellar fracture repair: treatment and results. J Knee Surg. 2013 Oct;26(5):309-12. doi: 10.1055/s-0033-1353990. Epub 2013 Aug 16. PMID: 23955187.
Shea GK, Hoi-Ting So K, Tam KW, Yee DK, Fang C, Leung F. Comparing 3 Different Techniques of Patella Fracture Fixation and Their Complications. Geriatr Orthop Surg Rehabil. 2019 Mar 5;10:2151459319827143. doi: 10.1177/2151459319827143. PMID: 30858993; PMCID: PMC6402069.
Driving. Danilkowicz, R., Tainter, D., & Gage, M. (2020). Return to driving after fracture an overview of current recommendations. Current Orthopaedic Practice, 31(4), 408–411. doi:10.1097/bco.0000000000000877
Image : Larangeira, João & Bellenzier, Liliane & Rigo, Vanessa & Neto, Elias & Krum, Francisco & Ribeiro, Tiango. (2015). Vertical Open Patella Fracture, Treatment, Rehabilitation and the Moment to Fixation. Journal of Clinical Medicine Research. 7. 129-133. 10.14740/jocmr2005w.
Written by Nelly Darbois
I love writing articles based on my experience as a physiotherapist (since 2012), scientific writer, and extensive researcher in international scientific literature.
I live in the French Alps 🌞❄️, where I work as a scientific editor for my own website, which is where you are right now.