What is an ACL Tear?
The ACL is a ligament that connects the femur, or thighbone, to the tibia, or leg bone. Its function is to keep the tibia from sliding too far forward on the femur. An ACL tear is a rupture of this ligament. When the ligament is torn, the knee can become unstable.
What causes an ACL Tear?
An ACL tear usually results from a sports injury. The majority of ACL tears occur as ‘non-contact’ injuries. They can result from sudden changes in direction, a slip or catching a cleat on turf. A blow to the outside of the knee, as occurs during a football tackle, is another common mechanism. ACL tears can be associated with trauma to the knee, including skiing accidents.
What are the symptoms?
Patients who have just torn their ACL will complain of pain, swelling, and inability to bear weight on the leg. The swelling prevents straightening the knee, or bending it all the way back. Because the knee swelling and pain subside after a few weeks, many patients will assume their knee has healed. Because the ligament is detached from the bone, it cannot heal, and will lead to instability of the knee. Patients with ACL tears that have occurred in the past will complain of ‘buckling’ or ‘giving way’ of the knee. This generally occurs with movements that require sudden changes in direction, such as playing sports like basketball or soccer.
How is an ACL tear diagnosed?
Recent tears of the ACL can be difficult to detect on physical exam. The knee is swollen and painful, and patients often do not allow their surgeon to thoroughly examine the knee. On exam, your surgeon will press on the knee to determine if there is swelling inside the knee joint. The surgeon will then try to slide the tibia forward on the femur. If resistance to this movement is not felt, then the ACL is injured. For chronic tears, the surgeon will attempt to partially dislocate the knee by bending and twisting it at the same time. If the knee comes partially out of joint, the ACL is torn. X-rays may show swelling in the joint, and in rare cases, will show an avulsion fracture of the bone that is associated with ACL tears. They are usually normal, however. An MRI is obtained to evaluate the ACL and other structures inside the knee. The ACL is usually well visualized on MRI, and tears can be readily identified. The ACL is usually detached from the femur. Other injuries commonly associated with ACL tears are meniscal tears, medial collateral ligament tears and bone bruises. Bone bruises are areas of swelling seen inside the bone, where the femur smashed into the tibia at the time the ACL was injured. They are most often seen in traumatic tears of the ACL, and can only be identified on MRI. Arthritis may later develop in the cartilage adjacent to bone bruises, as a result of damage to the cartilage that occurred at the time of the original injury.
How is it treated?
Non-operative
For young, active patients, surgery to reconstruct the ACL is generally recommended. The natural history of ACL tears has been studied extensively, and if the injured ligament is not reconstructed, arthritis develops in the knee. For older patients, non-athletes, or those with arthritis, physical therapy and bracing is recommended. For recent injuries, your surgeon will prescribe anti-inflammatory medications, crutches and physical therapy. It is important for the inflammation in the knee to resolve prior to surgery. Inflamed knees that undergo ACL surgery are more likely to develop motion loss post-operatively. Therefore, your surgeon will usually wait for the swelling in the knee to subside and motion to return to near normal before proceeding with surgery. An exception is made for patients with other injuries, such as a displaced meniscal tear, that prevent the knee from bending normally.
Operative
An ACL reconstruction is recommended for active patients. The reconstruction is performed arthroscopically, or arthroscopically assisted. A graft is taken from the patient’s quadriceps, hamstrings, patellar tendon or from a cadaver. The type of graft chosen must be individualized to each patient, and should be discussed with your surgeon. Once the graft is harvested, the surgeon drills a tunnel in the leg bone into the knee joint. A second tunnel is drilled in the thighbone, and the graft is passed inside of both tunnels and secured in place.
Post-operatively, physical therapy is started to regain motion and strength. Most athletes may return to sports around six months after the operation.
Posterior Cruciate Ligament (PCL)
What is a Posterior Cruciate Ligament Tear?
The PCL is a ligament that connects the femur, or thighbone, to the tibia, or leg bone. Its function is to keep the tibia from sliding too far backward on the femur. A PCL tear is a rupture of this ligament. When the ligament is torn, the knee can become unstable.
What causes a Posterior Cruciate Ligament Tear?
A PCL tear usually results from trauma, such as a direct fall onto the knee. Motor vehicle accidents, in which the knee strikes the dashboard and the leg bone is driven backward, are another common cause.
What are the symptoms?
Patients who have just torn their PCL will complain of pain, swelling, and inability to bear weight on the leg. The swelling prevents straightening the knee, or bending it all the way back. Because the knee swelling and pain subside after a few weeks, many patients will assume their knee has healed. Because the ligament is detached from the bone, it cannot heal, and may lead to instability of the knee. Patients with PCL tears that have occurred in the past may complain of ‘buckling’ or ‘giving way’ of the knee. This generally occurs with athletic movements. Some patients may have pain in the front of the knee below the kneecap. This occurs because pressure in the patellofemoral joint is increased in patients with PCL ruptures. Many patients with PCL tears will have no symptoms.
How is a PCL Tear diagnosed?
Recent tears of the PCL can be difficult to detect on physical exam. The knee is swollen and painful, and patients often do not allow their surgeon to thoroughly examine the knee. On exam, your surgeon will press on the knee to determine if there is swelling inside the knee joint. The surgeon will look for a posterior sag to the knee, then try to slide the tibia backward on the femur with the knee bent to ninety degrees. If resistance to this movement is not felt, then the PCL is injured. For chronic tears, the surgeon will attempt to push the tibia backward and away from the femur. X-rays may show swelling in the joint, and in rare cases, will show an avulsion fracture of the bone that is associated with some PCL tears. If this fracture is present, immediate surgery to repair the fracture and the ligament should be considered. An MRI is obtained to evaluate the PCL and other structures inside the knee. The PCL is usually well visualized on MRI, and tears can be readily identified.
How is it treated?
Non-operative
For patients without an associated bony injury, physical therapy is begun to regain motion and strength. If symptoms in the knee persist, reconstruction of the PCL should be considered. A brace may be prescribed to support the knee during sports activities.
Operative
Patients with a PCL avulsion fracture should have this repaired. An incision is made in the back of the knee, and a screw and washer are used to hold the fragment in its original position. For symptomatic tears without bony involvement, a PCL reconstruction is performed. A graft, usually made from an Achilles tendon is prepared. The surgeon drills a tunnel in the leg bone into the knee joint. A second tunnel is drilled in the thighbone, and the graft is passed inside of both tunnels and secured in place. Post-operatively, physical therapy is started to regain motion and strength. Most athletes may return to sports around six months after the operation.
Medial Collateral Ligament (MCL)
What is a MCL Tear?
A medial collateral ligament tear is an injury to the band of tissue that holds the inside of the thighbone to the inside of the shinbone. There are three Grades of MCL tears. In Grade I tears, the ligament is stretched. In Grade II tears, some of the fibers are torn, and in Grade III tears, all of the fibers are torn.
What causes a MCL Tear?
Twisting injuries or a direct blow to the outside of the knee cause injuries to the MCL. A common example is a football tackle in which the tackler’s shoulder strikes the outside of ball carrier’s knee, causing it to bend inward.
What are the symptoms?
Patients complain of pain and swelling on the inside of the knee. Knee motion causes pain, and the patient is usually unable to bear weight on the knee. A ‘pop’ is sometimes heard or felt at the time of injury.
How is a MCL tear diagnosed?
On physical exam, your surgeon will press on the ligament, reproducing pain. Applying pressure to the outside of the knee causes pain on the inside, and in Grade II and III tears, the bones will separate slightly. X-rays are usually normal, but may show an avulsion fracture at the MCL attachment site. An MRI can be ordered to confirm the diagnosis and look for other injuries in the knee, such as ACL and meniscal tears.
How is it treated?
Non-operative
Almost all tears of the MCL can be treated non-operatively. Your surgeon will prescribe physical therapy, anti-inflammatory medication and a brace to support the knee. The brace is worn for 6-8 weeks. Range of motion of the knee is limited for the first month.
Operative
Your surgeon will recommend an operation if an MCL tear is associated with other knee ligament injuries, or if it does not heal on its own. For tears that require surgery and have just occurred, the surgeon will repair the MCL. For chronic tears in which the knee remains unstable, the ligament can be tightened or reconstructed with a graft.
Lateral Collateral Ligament Tear(LCL)
What is a LCL Tear?
A Lateral Collateral Ligament tear is an injury to the band of tissue that holds the outside of the thighbone to the fibula (smaller of the two leg bones). There are three Grades of LCL tears. In Grade I tears, the ligament is stretched. In Grade II tears, some of the fibers are torn, and in Grade III tears, all of the fibers are torn. The posterolateral corner is the name for the group of ligaments, including the LCL, that support the outside back of the knee. Isolated injuries to the LCL are uncommon, and usually a posterolateral corner tear is identified.
What causes a LCL Tear?
Twisting injuries or a direct blow to the inside of the knee cause injuries to the LCL and posterolateral corner.
What are the symptoms?
Patients complain of pain and swelling on the outside of the knee. Knee motion causes pain, and the patient is usually unable to bear weight on the knee. A ‘pop’ is sometimes heard or felt at the time of injury.
How is a LCL tear diagnosed?
On physical exam, your surgeon will press on the ligament, reproducing pain. Applying pressure to the inside of the knee causes pain on the outside, and in Grade II and III tears, the bones will separate slightly. If the surgeon holds the leg in the air, the knee may appear to sag. Knees with injuries to the posterolateral corner will have increased external rotation compared to uninjured knees. X-rays are usually normal, but may show an avulsion fracture at the LCL attachment site. An MRI can be ordered to confirm the diagnosis and look for other injuries in the knee, such as ACL and meniscal tears.
How is it treated?
Non-operative
Partial tears of the LCL and posterolateral corner can be treated non-operatively. The knee is held straight in a brace or cast for 3 weeks and weight bearing is limited. Physical therapy is started after initial immobilization, and your surgeon will order a brace that pushes the knee inward. This takes stress off the soft tissue on the outside of the knee, allowing it to heal.
Operative
Your surgeon will recommend an operation if the LCL or posterolateral corner is completely torn or is associated with other knee ligament injuries. For tears that require surgery and have just occurred, the surgeon will repair the ligaments. For chronic tears in which the knee remains unstable, the ligament can be tightened or reconstructed with a graft.
Quadriceps Tendon
What is a Quadriceps Tendon Rupture?
A Quadriceps Tendon Rupture is a tear of the tendon that connects the muscles of the thigh to the kneecap. The tendon usually detaches from the top of the kneecap.
What causes a Quadriceps Tendon Rupture?
Trauma, such as a direct blow to the front of the knee, is a common cause.
What are the symptoms?
Patients will feel a ‘pop’ in the knee, followed by immediate pain, swelling, and the inability to straighten the knee. Patients will have trouble lifting the leg off the ground, and are unable to walk.
How is a Quadriceps Tendon Rupture diagnosed?
On physical exam, a defect will be felt at the site where the tendon attaches to the kneecap. Swelling is present in the joint, and the patient is unable to perform a straight leg raise. Pressing on the defect causes significant pain. On X-ray, the kneecap may be sitting lower than normal in the knee. In cases where there is severe swelling, a significant soft tissue envelope, or other suspected injuries, an MRI is ordered.
How is it treated?
Non-operative
Unless the patient’s other medical conditions prohibit surgery, operative treatment is recommended.
Operative
Your surgeon will make an incision in the front of the knee. The quadriceps tendon is mobilized, the ends of the tendon freshened to healthy tissue, and sutures are placed in the tendon. The top of the kneecap is trimmed to a bleeding surface to promote healing, and tunnels are drilled vertically through the kneecap. The sutures are passed through these tunnels and tied, tightly holding the tendon against the bone. Early therapy for range of motion is started, and the patient is allowed to walk with the knee out straight. Once the tendon is healed to the bone, strengthening exercises are begun.
Patellar Tendon Rupture
What is a Patellar Tendon Rupture?
A patellar tendon rupture is a tear of the tendon that connects the kneecap to the leg bone. The tendon usually detaches from the bottom of the kneecap.
What causes a Patellar Tendon Rupture?
Trauma, such as a direct blow to the front of the knee, is a common cause.
What are the symptoms?
Patients will feel a ‘pop’ in the knee, followed by immediate pain, swelling, and the inability to straighten the knee. Patients will have trouble lifting the leg off the ground, and are unable to walk.
How is a Patellar Tendon Rupture diagnosed?
On physical exam, a defect will be felt at the site where the tendon attaches to the kneecap. Swelling is present in the joint, and the patient is unable to perform a straight leg raise. Pressing on the defect causes significant pain. On x-ray, the kneecap may be sitting higher than normal in the knee. In cases where there is severe swelling, a significant soft tissue envelope, or other suspected injuries, an MRI is ordered.
How is it treated?
Non-operative
Unless the patient’s other medical conditions prohibit surgery, operative treatment is recommended.
Operative
Your surgeon will make an incision in the front of the knee. The patellar tendon is mobilized, the ends of the tendon freshened to healthy tissue, and sutures are placed in the tendon. The end of the kneecap is trimmed to a bleeding surface to promote healing, and tunnels are drilled vertically through the kneecap. The sutures are passed through these tunnels and tied, tightly holding the tendon against the bone. Early therapy for range of motion is started, and the patient is allowed to walk with the knee out straight. Once the tendon is healed to the bone, strengthening exercises are begun.
Meniscal Tear
What is a Meniscal Tear?
The meniscus, or knee cartilage, is a rubbery, shock absorber that sits between the bones of the knee. It cushions the inside of the knee when a patient walks or runs. There are two menisci, the medial and the lateral. The medial cushions the inside of the knee, and the lateral protects the outside of the knee. A meniscal tear occurs when one, or both, of these are torn.
What causes a Meniscal Tear?
Sudden, twisting motions can trap the meniscus between the bones of the knee, causing it to tear. The meniscus is composed of a connective tissue that becomes more brittle with age. Therefore, age-related degeneration of the meniscus is another common cause of tearing. These tears can occur without any specific injury.
What are the symptoms?
Patients with meniscal tears will complain of pain, swelling, ‘clicking’, ‘locking’ or ‘giving way’ of the knee. Because bending the knee puts more pressure on the meniscus, these patients will complain of pain with squatting and using stairs.
How is a Meniscal tear diagnosed?
Your surgeon will take a careful history and physical exam. On exam, pain is reproduced with pressure on the meniscus, bending the knee, or bending and twisting the knee. X-rays are generally normal, but may show arthritis or calcification of the meniscus, two conditions which are associated with meniscal tears.An MRI is obtained to confirm the diagnosis.
How is it treated?
Non-operative
If the tear can be treated non-operatively, your surgeon will prescribe physical therapy, anti-inflammatory medication and avoiding painful activities. A cortisone injection may be given into the knee to help relieve pain.
Operative
Because the meniscus has very little blood supply (only the outer third contains blood vessels), it has very little capacity to heal on its own. For athletes, patients with persistent symptoms such as buckling, or those with large, displaced tears, surgery is recommended. The surgery is performed arthroscopically and the surgeon will remove, or if possible, repair, the torn cartilage. Post-operatively, physical therapy is begun to restore strength and range of motion.