What Is a True Knee Dislocation and Why Is It Serious?
A true knee dislocation occurs when the thigh bone and shin bone completely separate at the knee joint. This rare but severe injury is considered a limb-threatening emergency as it can damage the popliteal artery, disrupt blood flow to the lower leg, and cause permanent tissue loss.
At Total Orthopedics and Sports Medicine, Dr. Charles Ruotolo performs an emergency medical assessment and reviews imaging tests to assess vascular integrity after a true knee dislocation. If he identifies arterial injury, he coordinates immediate vascular surgery to restore blood flow. Once the limb is stabilized, he develops a surgical plan that may include ligament reconstruction or meniscus repair to restore knee stability. Contact us to book your appointment at our Massapequa clinic.
Why Is a True Knee Dislocation Considered So Dangerous?
A true knee dislocation can cut off blood flow to the lower leg and foot, which may cause serious complications, including permanent muscle damage and tissue death. It can also result in popliteal artery injury and nerve damage, leading to foot drop, chronic pain, and long-term loss of leg function. In severe cases, prolonged loss of blood flow can even cause limb loss, requiring amputation of the affected leg.
Despite timely treatment and proper rehabilitation, a true knee dislocation can still cause long-term functional limitations. For example, according to Physiopedia, post-traumatic chronic osteoarthritis may develop in 50% of knee dislocation cases. This risk increases as the injury damages the articular cartilage, meniscus, and other structures that normally distribute pressure across the knee joint. As a result, you may experience chronic pain, stiffness, swelling, and difficulty with walking and climbing stairs years after the initial injury.
Here are some other consequences of a true knee dislocation injury:
- Arthrofibrosis: After a true knee dislocation, 38% of patients may develop scar tissue within the joint. As a result, you may struggle to bend or straighten your knee even after surgery.
- Compartment syndrome: A knee dislocation can lead to severe bleeding in the lower leg. This increases pressure within the muscle compartments, requiring prompt treatment.
- Nerve damage: Knee dislocations can tear the tibial and common peroneal nerves around the knee. For example, a PubMed study reported nerve injuries in 10%-40% of dislocation cases.
How Can You Tell If Your Knee Is Dislocated?
A true knee dislocation usually causes a loud popping sensation, severe pain, significant swelling, and a visible deformity around the knee joint. You may also be unable to bear weight, straighten your leg, or walk normally. Other than that, it can cause numbness, tingling, weakness, a cold foot, or absent posterior tibial pulses (lower leg and ankle) due to nerve damage.
Here are some other symptoms of true knee dislocation:
- A feeling that the knee has shifted out of its normal position
- Visible misalignment between the thigh bone and shin bone
- Bruising around the knee and lower leg
- Muscle weakness associated with common peroneal nerve injury
- Tightness or increasing pressure in the calf
- Difficulty moving the foot or toes
- Loss of sensation in parts of the lower leg or foot
- Pale or bluish discoloration of the foot due to reduced blood flow
- Signs of shock, such as dizziness, sweating, or a rapid heartbeat, may occur in severe cases
- An inability to lift the foot, causing the toes to drag during walking
What Are the Different Types of Knee Dislocations?
There are five major types of knee dislocation: anterior, posterior, lateral, medial, and rotary dislocation. This classification is based on the direction in which the shin bone moves against the thigh bone during a traumatic dislocation. Here are the common injury patterns involved in each type of knee dislocation:
Anterior Dislocation
Anterior dislocation is the most common type of true knee dislocation. According to a PubMed study, it accounts for approximately 40% of all knee dislocation cases. It usually occurs when a powerful hyperextension injury forces the knee beyond its normal range of motion. As the shin bone moves forward in relation to the thigh bone, the injury commonly tears the anterior cruciate ligament, posterior cruciate ligament, and other supporting knee ligaments.
Posterior Dislocation
Posterior dislocation occurs when the shin bone moves backward in relation to the thigh bone. This injury is also known as a dashboard injury because it commonly develops when the front of the shin strikes the dashboard during a motor vehicle accident while the knee is bent. It can also occur after a direct fall onto the shin bone with a flexed knee.
Lateral Dislocation
When the shin bone displaces laterally (outside) against the thigh bone, you may experience a lateral dislocation. This injury usually involves high-velocity trauma that applies a powerful side-to-side force to the knee. As a result, it can damage the lateral collateral ligament and posterolateral corner structures. In addition, lateral dislocation carries the highest risk of peroneal nerve injury, which can cause foot drop.
Medial Dislocation
A medial dislocation occurs when the shin bone shifts inward across the knee joint after a major side-impact injury. This injury is common during a motor vehicle collision, a skiing fall, or a high-speed pivot, in which the leg collapses outward. Because this movement strains the inner knee structures, it can tear the medial collateral ligament, the cruciate ligaments, the joint capsule, and the nearby cartilage.
Rotary Dislocation
A rotary dislocation develops when the knee twists forcefully while the foot remains planted on the ground. Unlike other dislocation patterns, this injury combines rotational and translational forces, which can simultaneously damage multiple ligaments, joint capsule structures, and surrounding soft tissues.
Are Athletes More Prone to Knee Dislocation?
Yes, athletes are at a higher risk of developing a true knee dislocation, especially in high-velocity sports such as downhill skiing, football, rugby, and soccer. These activities can expose the knee to violent twisting, hyperextension, or direct high-speed contact, which can tear multiple ligaments. In fact, according to the Indian Journal of Orthopaedics, sports injuries cause 33% of knee dislocations. Among those sports-related cases, skiing was the most common cause of knee dislocation, accounting for 62% of injuries.
In addition, here are some other sports-related actions that may increase the risk of knee dislocation in athletes:
- Landing awkwardly after a jump
- Sudden changes in direction while running
- Pivoting on a planted foot
- Direct collisions with another player
- Forceful contact to the front or side of the knee
- Skiing or snowboarding falls with the foot fixed in place
Can Knee Dislocation Lead to Long-Term Instability?
Yes, a true knee dislocation can lead to long-term instability. Even after healing, the torn ligaments, including ACL, PCL, MCL, and LCL, may not regain their original strength, tension, or positioning. As a result, they may struggle to maintain alignment between the thigh and shin bones. In such cases, you may experience knee buckling, a loose feeling inside the joint, or instability while walking or climbing stairs. Additionally, an unstable knee joint may cause recurrent giving-way episodes, which can increase your risk of falls and additional injuries.
What is the Difference Between True Knee Dislocation and Patellar Dislocation?
A true knee dislocation involves complete separation of the shin bone from the thigh bone at the knee joint. In contrast, a patella dislocation occurs when the kneecap slips out of its normal groove on the front of the knee. Similarly, a true knee dislocation is usually caused by high-energy trauma, such as a car accident or severe fall. On the other hand, a dislocated kneecap may develop during lower-energy movements, such as pivoting or sudden direction changes.
Additionally, the dislocated patella may return to its normal position on its own. In some cases, it may require manual repositioning by a doctor, who gently guides the patella back into its normal alignment. However, a true knee dislocation is an orthopedic emergency that typically requires prompt reduction to restore knee alignment and protect nearby blood vessels and nerves.
Then, surgeons check for vascular injury and coordinate emergency vascular surgery if blood flow is affected. After vascular surgery, they temporarily immobilize the knee with a brace, splint, or external fixator. Once your knee stabilizes, surgeons may proceed with a multi-stage surgery to repair the torn ligament, followed by structured rehabilitation to restore knee function.
What Is Popliteal Artery Injury After Knee Dislocation?
A popliteal artery injury after a true knee dislocation is a limb-threatening vascular emergency that damages the main artery behind the knee. As a result, blood flow to the lower leg can stop, which may cause permanent muscle damage and tissue death. According to the Journal of Orthopaedics, nearly 30% of knee dislocations are associated with popliteal artery injury after a high-energy trauma.
In such cases, surgeons typically review CT angiography results to assess the severity of a popliteal artery injury. This imaging test shows whether the artery is torn, blocked, narrowed, compressed, or leaking blood after the knee dislocation. It also helps identify the exact location and extent of the vascular injury, which guides treatment planning. In addition, surgeons often measure the ankle-brachial index (ABI) to determine blood flow in the lower leg. This test compares ankle blood pressure with arm blood pressure. An abnormal ABI may suggest reduced circulation from a popliteal artery injury and indicate the need for further vascular testing.
How Soon Should a Dislocated Knee Be Treated?
A tibiofemoral dislocation should be treated immediately with spontaneous reduction to realign the knee joint. Then, surgeons must assess blood flow, nerve function, and ligament damage. If the knee injury affects blood circulation, it is important to restore blood flow within 6 to 8 hours. According to a study published in PubMed, delays beyond this period can increase the risk of amputation by 86%.
What Surgical Options Can Help Restore Knee Stability?
To restore knee stability, Dr. Charles Ruotolo may perform multiligament reconstruction, primary repair, or external fixation. He may also recommend collateral ligament augmentation, meniscus repair, meniscus removal, or osteotomy. However, before recommending these procedures, he first assesses vascular injury, as interrupted blood flow can cause permanent muscle damage and tissue death. In such cases, our orthopedic specialist coordinates with vascular surgeons, who may perform bypass grafting to restore circulation.
Once blood flow is restored, our surgeon may proceed with the suitable knee dislocation surgery. Here’s how different surgical procedures help restore knee stability:
External Fixation
Surgeons may perform external fixation if your knee is severely unstable, swollen, or unsafe for immediate ligament surgery. In such cases, they use an external device to stabilize the thigh bone and shin bone from outside the body. Once the soft tissues, blood vessels, and surgical wounds have fully recovered, they may perform ligament reconstruction to restore knee stability.
Multiligament Reconstruction
If a knee dislocation tears multiple stabilizing ligaments, Dr. Charles Ruotolo may recommend multiligament reconstruction. During this surgery, torn ligaments are replaced with strong tissue grafts from the patient or a donor. Then, the surgeon anchors each graft to the thigh and shin bones, which restores the original ligament’s path.
Primary Ligament Repair
Primary repair is recommended when a ligament tears away from the bone but still has enough healthy tissue for reattachment. In this procedure, surgeons secure the torn ligament back to its attachment site using sutures or anchors.
Collateral Ligament Augmentation
If the MCL or LCL does not provide enough side-to-side stability after primary repair, Dr. Charles Ruotolo may perform collateral ligament augmentation. During this surgery, surgeons strengthen weakened ligaments with graft tissue or additional fixation. This helps reduce abnormal shifting and supports better knee alignment during recovery.
Meniscus Repair or Removal
If a knee dislocation damages the meniscus, surgeons repair the torn tissue whenever possible. During the procedure, they reposition the torn meniscus and secure it with specialized sutures or fixation devices. This allows the tissue to heal in its normal position, which helps preserve knee cushioning. However, if the torn portion cannot heal, surgeons may remove the damaged segment to reduce the risk of cartilage damage.
Osteotomy
Our knee specialist may recommend osteotomy when abnormal bone alignment places excessive stress on the knee joint. During this procedure, surgeons make a controlled cut in the femur or tibia to reposition the bone into a suitable alignment. Then, they secure the corrected position with plates and screws to improve stability and reduce long-term joint wear.
How Can Bracing Support a Dislocated Knee?
Bracing prevents hyperextension and side-to-side shifting of the knee, which supports healing ligaments and the joint after reduction. If you underwent surgery, the brace also protects ligament repairs or grafts from early stress, loosening, or re-injury. Similarly, adjustable braces allow controlled movement within safe limits, which helps maintain mobility and reduce stiffness.
Here are some additional benefits of bracing in a true knee dislocation:
- Improves knee stability during walking and daily activities
- Helps maintain the proper alignment of the tibia and femur during healing
- Reduces the risk of recurrent dislocations and sudden buckling episodes
- Increases confidence during weight-bearing activities
- Provides support during the transition from crutches to independent walking
- Allows doctors to progressively increase the range of motion as healing progresses
- Helps distribute forces more evenly across the knee joint
In most cases of true knee dislocation, surgeons recommend a hinged knee brace, particularly during the early stages of active recovery after a multi-ligament injury. Unlike standard knee braces, hinged designs provide greater stability while still allowing controlled movement. Many models, such as T-scope braces, can be adjusted to gradually increase knee flexion and extension as the knee healing progresses. As you progress through rehabilitation, your surgeon may recommend a lighter functional hinged brace. This brace supports reconstructed ligaments during strengthening exercises, walking progression, agility training, and return-to-sport activities.
What is the Most Common Complication After Knee Dislocation Surgery?
After knee dislocation surgery, arthrofibrosis (stiffness caused by scar tissue) is one of the most common complications. In fact, an Orthopaedic Journal of Sports Medicine study found that 16.7% of multiligament knee surgeries resulted in arthrofibrosis. It was followed by wound infection at 6.5% and deep vein thrombosis at 1.8%. The same review reported revision ligament surgery in 5.6% of cases.
Can You Fully Recover from a Dislocated Knee?
Yes, you may fully recover from a dislocated knee. According to our experience, many patients successfully return to their normal daily activities after 9 to 12 months of structured orthopedic care. However, a significant percentage of individuals may find it difficult to resume physically demanding jobs or high-level sports. In many cases, they may still notice mild stiffness or weakness, which may reduce confidence during activities that involve twisting, pivoting, or sudden changes in direction.
To prevent long-term functional limitations, our surgeon, Dr. Charles Ruotolo, follows a structured recovery plan that includes the following steps:
Weeks 0 to 6: Protection and Early Healing
During the first 0 to 6 weeks, the primary goal is to protect the healing knee ligaments and surrounding soft tissues. Therefore, you may need a knee brace, crutches, or other assistive devices to limit weight bearing. To manage pain, our surgeon may also prescribe anti-inflammatory medications, short-term pain relievers, icing routines, leg elevation, and compression.
In addition, he also recommends the following gentle range-of-motion and muscle-activation exercises to reduce stiffness and maintain early knee function:
- Heel slides
- Quadriceps sets
- Straight leg raises
- Assisted knee flexion exercises
- Patellar mobility exercises
Months 2 to 6: Restoring Strength
Once the healing tissues can tolerate activity, our top knee surgeon recommends strengthening exercises. During this phase, you may perform stationary cycling, leg presses within a controlled range, step-ups, and balance training. Similarly, targeted quadriceps and hamstring exercises help restore knee function while reducing the risk of chronic instability.
Months 6 to 12: Return to Higher-Level Activity
Between 6 and 12 months, knee dislocation recovery plans focus on advanced strength, coordination, and movement control. For example, you may be advised to perform jogging drills, single-leg balance exercises, agility ladder drills, and lateral movement training. These activities help restore knee stability, improve movement mechanics, and prepare you for a safe return to higher-level physical activity.
However, before allowing you to resume unrestricted activity, Dr. Charles Ruotolo performs the following physical tests to confirm full healing:
- Ligament stability testing (Lachman test, posterior drawer test, etc.)
- Single-leg balance assessment
- Strength comparison between the two legs
- Squat and step-down movement analysis
- Pain response during functional movements
- Walking and jogging mechanics assessment
Struggling to Walk After Knee Dislocation? Book an Appointment with Dr. Charles Ruotolo in Massapequa!
A true knee dislocation can cause severe pain, loss of knee function, and serious injury to nearby blood vessels and nerves. Without prompt treatment, the injury can lead to permanent muscle damage, tissue death, and chronic instability. In severe cases, it may even require amputation, which can result in lifelong functional limitations.
At Total Orthopedics and Sports Medicine, Dr. Charles Ruotolo coordinates imaging, pain management, and surgical care under one roof to quickly treat true knee dislocations. As a member of the Arthroscopy Association of North America, he uses advanced minimally invasive techniques whenever appropriate to minimize surgical trauma. Contact us now or visit 5500 Merrick Road, Massapequa, NY, to consult Dr. Charles Ruotolo.
FAQs
How Long Does Recovery Take After A Knee Dislocation?
Recovery time after a true knee dislocation ranges from 9 to 15 months. However, the exact timeline may depend on factors such as your age, overall health, body weight, the severity of ligament damage, and associated injuries like fractures or meniscus tears.
Is A Knee Dislocation Worse Than An ACL Tear?
Yes, a true knee dislocation is much more serious than an ACL tear. An ACL tear is a single-ligament injury. In contrast, a true knee dislocation typically tears at least three of the four major stabilizing knee ligaments, including the anterior cruciate ligament and posterior cruciate ligament.
How Long Does Swelling Last After A Knee Dislocation?
After a knee dislocation, significant swelling usually lasts 4 to 6 weeks. After this period, mild swelling may persist for up to 3 to 6 months. However, the exact duration of swelling depends on the severity of the injury, the extent of ligament damage, and the type of surgical treatment.
How Is A True Knee Dislocation Diagnosed?
To diagnose a true knee dislocation, surgeons perform an emergency physical exam and review imaging studies such as MRI scans and CT angiography. During the examination, they check for severe swelling, obvious deformity, and joint instability to confirm knee dislocation. They also assess the ankle-brachial index (ABI) to identify nerve damage.
Can A Knee Dislocation Happen Without Trauma?
Yes, a true knee dislocation can occur without major trauma in rare cases. For example, people with severe joint disease, ligamentous laxity, or morbid obesity may experience a dislocation after a low-energy event such as a misstep. However, most knee dislocations occur after high-energy trauma, such as a car accident.
