Most people have heard of an ACL injury, which amateur and elite athletes of all ages commonly suffer. But a posterior cruciate ligament (PCL) injury accounts for up to 20% of acute knee injuries. So, what is a PCL tear in the knee, and how do we treat it?
What is the posterior cruciate ligament?
The posterior cruciate ligament (PCL) is one of the four main ligaments that stabilise the knee. The ACL and PCL crisscross the knee, providing support and preventing the knee from moving forward or backwards. The PCL’s main role is to stop the tibia (shin bone) from sliding backwards against the femur (thigh bone).
How does a knee PCL tear occur?
The most common mechanism is a force striking the front of the shinbone, driving it backwards and tearing the PCL. A torn PCL is often called a “dashboard injury” after car collisions in which the knee strikes the dashboard. We also see PCL tears when athletes fall directly onto the front of the knee or when the knee suddenly hyperflexes.
A PCL tear is often associated with injuries to other structures, such as the posterolateral corner, the ACL, or the meniscus.
How is a PCL tear diagnosed?
A torn PCL is often — though not always — associated with sudden pain, swelling, and a feeling of instability. Some people hear a pop or feel the knee give way and report they can’t trust the knee with certain movements.
A PCL tear can be subtle, particularly a partial tear that causes minimal pain and swelling. Even then, the knee often feels wrong and is slow to recover.
Your doctor examines the knee to check whether the PCL is intact. The most reliable test is the posterior draw test; others include the posterior sag sign and the reverse pivot shift. We also test the other ligaments — the MCL, LCL, ACL, and posterolateral corner — to make sure there are no other injuries. The knee often has a limited range of motion and swelling.
X-ray and MRI confirm a torn PCL and rule out other ligament or cartilage damage. A PCL tear is graded by severity: grade 1 is a sprain, grade 2 a partial tear, and grade 3 a full tear.
Treatment of a PCL tear
The treatment of PCL injuries — especially grade 3 — is debated, with little agreement on the best approach.
Grade 1 and mild grade 2 injuries are treated with simple measures first: ice, ibuprofen, compression, and range-of-motion exercises. Higher-grade 2 and 3 injuries are often treated with a knee brace to help stabilise the knee.
Knee support for a PCL tear
While there’s some controversy about whether a brace helps after a PCL tear, most doctors recommend wearing one for 6 weeks after the injury. The brace pushes the shin bone forwards, allowing a torn PCL to heal. One example is the PCL jack brace, which limits movement from 0 to 90 degrees and is used only in the early stages of rehab, though the ideal duration of wear is unknown.
PCL exercises
Strengthening and balance exercises are essential to regain knee function. We start with range-of-motion work, then progress to non-weight-bearing and weight-bearing quadriceps and calf exercises. It’s best to avoid hyperextension and exercises that push the shin bone backwards, such as isolated prone hamstring curls. The aim is to restore strength, balance, and control before restarting running and sport-specific training.
Surgery for a PCL tear
Surgical reconstruction is uncommon for a torn PCL, except in a few situations:
- A grade 3 injury with symptoms of instability
- A grade 3 injury with other injuries, such as a posterolateral corner or LCL tear
PCL reconstruction is technically more complex than the more common ACL reconstruction and needs at least 12 months of rehabilitation.
Frequently asked questions about a PCL tear
How long does it take to recover from a PCL injury?
A PCL tear can take up to six months to recover with non-operative treatment, and sometimes longer, as the knee adapts to a deficient PCL. In some cases, the forces on the kneecap or the inside (medial) compartment increase, leading to early arthritis — but these usually settle with solid rehab, and occasionally cortisone, hyaluronic acid, or PRP injections.
ACL vs PCL injury: how can you tell?
Both can happen during sport, but an ACL injury usually follows a sudden stop, a change of direction, or an awkward landing, and shows looseness when moving the shin bone forwards (Lachman’s test). An ACL rupture often needs surgical reconstruction in young people, whereas most PCL tears are treated without surgery.
Does a PCL tear lead to early arthritis?
It can. A PCL injury increases forces on the kneecap and the medial compartment, and over a few years, this can damage cartilage and lead to early arthritis. Keeping the muscles strong with rehab helps protect the knee.
How do we treat a PCL avulsion?
In teenagers, the top attachment of the PCL can tear away with a small piece of bone — a PCL avulsion. If detected early, these can be reattached so the PCL functions normally, which is why it’s always important to X-ray a teenager with a swollen knee after trauma.
Does a grade 1 or 2 PCL injury need surgery?
Usually not. We suggest surgery only for grade 3 PCL injuries, especially when combined with other injuries such as a posterolateral corner or medial meniscal injury. Grade 2 injuries usually do well with rehabilitation.
Can you return to sport after a PCL tear?
Often, yes — even after a grade 3 tear — provided you don’t have instability or other major injuries. Most people return to running and sport with a sustained rehabilitation programme over six to nine months, guided by a good physiotherapist.
Do you need a brace for a PCL tear?
For higher-grade injuries (grade 2–3), a brace is commonly used for about six weeks to support healing. Lower-grade injuries often don’t need one. Your doctor will advise whether a brace such as the PCL jack brace suits your injury.
Final word from Sport Doctor London about a PCL tear
A PCL tear is less common than an ACL injury but accounts for a significant proportion of acute knee injuries. Most isolated PCL tears — even grade 3 — are treated successfully without surgery, using bracing where needed and a sustained rehabilitation programme. Surgery is reserved for instability or combined ligament injuries. An accurate diagnosis, including assessment of the other knee ligaments, is essential.
If you have a knee injury and suspect a PCL tear, Dr Masci can assess you in London. Contact the team here or call +44 (0) 203 488 0350.
I have been detected with pcl avulsion, what is the best treatment
If you diagnose an avulsion early, fixation is possible.
Would a grade 1 – 2 tear of the PCL and PLC immediately require surgery or is there the possibility of natural healing?
Generally, I don’t recommend surgery for isolated grade 1-2 PCL injuries. Sustained rehab over 6-9 months should enable you to get back to full function.
LM
I have a grade 3 PCL tear. I use to enjoy sport like trail running which requires a lots of balance and stability. Will I be able to do this again if the PCL is not surgically repaired?
Yes, unless you develop instability or you have other major injuries – as outlined in my blog. You should see a good physical therapist to help you.
LM
I have a pcl tear. The ortho said grade 2 but it’s a complete tear. I didn’t need crutches and was walking pretty good in 3-4 days.
I am an off-road triathlete and want to return to trails esp running. Would I need surgery?
Hi Lucia,
In general, an isolated high-grade PCL injury only needs surgery if you have co-existing instability (giving way). I’d try rehab first.
LM
40 years ago I had a complete PCL tear. No surgery was available back then. I did manage to recover. Same knee 20 years ago had same knee ACL repair. Recovered fine. Again I had an injury that might have tore my PCL! Haven’t had it examined yet but all the classic symptoms of PCL involvement. Is it time for a replacement!? I’m an active 62 yo female
Hi it’s only tome for a replacement if you’re getting knee pain and swelling secondary to osteoarthritis. Generally, I recommend a knee replacement if your step count falls to less than 7000 steps/day.
Hi, I have a complete PCL tear after MRI scan. It’s been almost 2 months, aI met an accident I am able to walk now but still swelling is there, pain is reducing gradually. Doctor has suggested PCL reconstruction.My knee is not that stable and I have difficulty in coming down in stairs. I am not ready for the surgery for reconstruction. can you please suggest what can be done to get rid of this? Do you think that proper rehab and physiotherapy would be able to help me to get rid of the current situation without reconstruction? And will be the long term effect can become serious if I don’t go for reconstruction for complete PCL tear? Please suggest. (I am sure that I will not be doing any heavy sports activities)
Thanks a lot in advance.
Hi Amit, it depends on various factors as I outlined in the blog – other injuries, co-existing posterolateral corner injury. Overall, PCL reconstruction is a huge undertaking, so you want to ensure you absolutely need it. I’d suggest a second opinion. LM
hi, I hit a car accident 5 weeks ago and find PCL is torn. Dr advised me to take the surgery after checking the drawer test. I can feel my knee loosen a little bit. I read some papers about PCL surgery and they mention that the PCLR can help reduce further degradation. I am really worried about the surgery and also have great concerns about the future. Can you give me some advice?
as I mention in the blog, surgery is indicated if you have instability or other associated injuries.If you have just an isolated PCL injury, then treatment could be conservative – but you should speak to your doctor.
I have a “high grade” partial tear of the PCL and grade 1 MCL injury following a fall. Would this require surgery?
hi Ed,
I would say no. Partial tears of PCL usually don’t require surgery, but you should speak to your doctor about options.
Lorenzo
I had grade 3 full thickness tear in the centre of my PCL in December 2024 , i was on crutches for a few weeks before i got the results of the mri. Since confirming the PCL tear i have been advised by the consultants to speak to physiotherapy , however I’ve spoken with 3 physios now who have all told me i need to go back to the consultant for them to look at a treatment plan moving forward . consider surgery . I wasn’t given a brace however I am now able to do most things and I’m able to exercise other than the ability to kneel down. is this something i can recover from without surgery , i have a very active job that has heavy physical demands
Possibly if you have an isolated grade 3 PCL without instability – although a grade 3 injury will place you at greater risk of medial and patellofemroal compartment osteoarthritis. I’d only consider surgery if you have symptoms or signs of instability.
Hello
I was diagnosed with a grade 2 PCL tear..I’ve had no instability symptoms. I got back to doing my normal exercise mainly cycling, if I do to much hard racing I get bad swelling for a few weeks then the knee returns to normal with rest this has happened twice since my accident 5 months ago im having physio I just wanted know will the swelling eventually stop ? So I can return to racing again.
Thankyou
Assuming you don’t have other pathology in your knee, I suspect your knee symptoms will eventually settle with a progressive rehab programme. In PCL injuries, the dynamics of the joint changes so more load is placed on the patellofemoral and medial compartments – which can lead to pain and swelling. Sometimes, I use injections – hyaluronic acid or PRP – to help with the swelling especially if you have underlying degenerative changes in the knee. https://sportdoctorlondon.com/arthrex-acp-max/
https://sportdoctorlondon.com/durolane-injection/
Hello my 23 year old son was a soccer player and injured his calf and knee several years ago. Doc told him to do physical therapy and the therapist said he had a torn calf muscle. No imaging. Helped a little but never fully recovered. Fast forward he now has a decent sag sign, he has a lot of pain with bending, minimal swelling but also feel what seems to be a bakers cyst posterior to the knee. He is able to run and exercise without instability but he is in pain. Ligament laxity . Was going to get him and X-ray and mri . Should he consider surgery with the continued pain if pcl tear is confirmed? And what about the bakers cyst?
Hi, Your son needs further clinical assessment (by a sports doctor or orthopaedic surgeon) and imaging to exclude other injuries to the knee such as meniscal, articular cartilage damage or other ligament injuries. See my comments about surgery for PCL injuries – generally we suggest surgery for instability or combined ligament injuries (PCL and posterolateral ligament injuries).
LM