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Knee Surgery & Rehabilitation

There are 4 main ligaments in the knee that help keep the joint stable when we walk, run, go up and down stairs, kneel, and do any weight bearing activity. In addition, the muscles and other soft tissues in the knee joint help provide stability. While the anterior cruciate ligament (ACL) and medial collateral ligament (MCL) are commonly torn, the posterior cruciate ligament (PCL) and lateral collateral ligament/posterolateral structures (LCL/PLS) may also be injured and cause considerable problems if left untreated.

Pioneers in Knee Medicine making the best treatment

The primary LCL/PLS are the:

  • Lateral collateral ligament (also referred to as the fibular collateral ligament)
  • Popliteal muscle-tendon-ligament unit (including the popliteofibular ligament)
  • Posterolateral capsule

These soft tissues work together to prevent 4 problems from occurring: excessive widening of the outside of the knee joint, outward (external) rotation of the tibia, knee hyperextension (bending too far backwards), and varus recurvatum (knee hyperextension and bowing outward).

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Tears to the LCL/PLS frequently occur along with tears to either the ACL or PCL. These injuries are difficult to treat and often go undiagnosed. At the Noyes Knee Institute, we have unfortunately seen many patients in whom the initial injury to the LCL/PLS was not treated effectively. For instance, if a patient tears both the LCL/PLS and ACL, but only the ACL is reconstructed, the surgery may fail. Leaving a completely deficient knee ligament alone greatly increases the failure rates of reconstructions of other ligaments. Dr. Frank Noyes is internationally recognized for his work in the diagnosis and treatment of injuries to the LCL/PLS and has published many studies on the treatment and outcome of surgery for this injury.

Why Choose NKI for your ACL Reconstruction

The diagnosis and treatment of these injuries require the expertise of highly trained and experienced medical personnel such as those at the Noyes Knee Institute. We have treated patients with these injuries for over three decades.

Frequently Asked Questions

Ligament Injuries What you need to know:

How do I know if I've injured the LCL/PL knee structures?

The LCL/PL are frequently torn during a contact injury, such as a direct blow to the inside (medial) of the knee, or as a result of a twisting or hyperextension injury (knee bending too far backwards). The injury results in:

  • Pain
  • Knee swelling
  • Inability to flex and extend the knee fully
  • Instability

Over time, problems that may happen to patients who have chronic injuries to the LCL/PLS include:

  • Pain and instability with squatting, kneeling, stair climbing and descending, and rising from a chair.
  • Knee extends too far backwards (hyperextend) or bows outward, making it painful and unstable and change the way a patient normally walks. This gait problem may then cause problems to the hips and back.
  • Knee arthritis. Symptoms of knee arthritis include pain and swelling with sports and then, as the damage progresses, with daily activities

How does the doctor tell if the LCL/PL are injured?

The orthopaedic surgeon will conduct a comprehensive knee examination that includes:

  • Tests to determine the function of the ligaments
  • Tests to determine if meniscus tears are present
  • Tests to measure muscle strength and function
  • An assessment of how the patient walks
  • Determination of the overall alignment of the lower limb
  • X-rays
  • MRI

How are injuries to the LCL/PLS treated?

Once detected, the decision of how to treat LCL/PLS injuries requires an orthopaedic surgeon with experience performing various operations and directing physical therapy. The LCL/PLS may be partially or completely torn. The decision on how to treat the problem depends on the extent of the damage and how much time has elapsed between the injury and medical examination.

If a very small amount of damage to the LCL/PLS is detected, the patient may be treated without a brace or crutches and gradually return to activities based on their symptoms. Some patients may require a soft support brace for a few weeks and are progressed back to activities based on their symptoms.

In patients who have acute knee injuries with complete LCL/PLS tears, surgery must be delayed. The knee is immobilized in a cast to allow healing. Crutches are used, with only a small amount of weight allowed on the leg. The patient performs quadriceps isometrics exercises every hour they are awake. After 1 week, the cast is split into 2 pieces to form a bivalved cast. This allows the therapist to remove the cast and perform range of knee motion exercises. Other safe muscle strengthening exercises are performed. Symptoms of pain and swelling are treated as well. After at least 6-8 weeks, consideration for surgery is made based on several factors discussed next.

Who are candidates for surgery?

Patients considered for surgery:

  • > 5 mm of increased lateral joint opening
  • > 15 degrees increased external tibial rotation
  • Usually a tear to the ACL or PCL in addition to the tear to the LCL/PLC
  • Sometimes a prior failed ACL and/or PCL reconstruction in addition to the tear to the LCL/PLC
  • Varus recurvatum in the standing and supine positions may or may not be present
  • Hyperextension gait may or may not be detected
  • Varus malalignment (bowed leg)

The indications for reconstruction of the LCL/PLC are further verified at surgery after the patient has been placed under anesthesia. Using the arthroscope, a test is done by the surgeon that measures the amount of joint opening (space between the femur and tibia) under pressure. This provides the final indicator that severe deficiency of the posterolateral structures exists and must be surgically corrected.

Who are NOT candidates for surgery?

Patients are not considered for surgery who have:

  • < 5 mm increased lateral joint opening
  • < 10 degrees increased external tibial rotation
  • Varus malalignment (bowed leg), where a high tibial osteotomy will correct the increased lateral joint opening and external tibial rotation
  • Varus malalignment in a patient who refuses to undergo a high tibial osteotomy
  • Experienced a previous joint infection
  • Severe muscle atrophy and/or hyperextension gait abnormality: these problems must be corrected first before surgery can be considered
  • Morbid obesity: significant weight loss must be accomplished first before surgery can be considered
  • Severe arthritic damage in the knee
  • The inability or unwillingness to be compliant with postoperative rehabilitation

How is the surgery done?

Many different surgical techniques have been described to reconstruct the LCL/PLS. The more common operations that are done today replace the LCL and (if necessary) the popliteal-muscle-tendon-ligament unit and popliteal fibular ligament with tendon grafts taken either from the patient’s own tissues or a donor’s tissues. It is important to replace or repair all of the damaged structures. In addition, the posterior capsule may require repair to prevent excessive knee hyperextension.

In some knees, the LCL/PLS are intact but lax and have not been replaced by scar tissue. All tissues appear normal, except they are slightly elongated. In these cases, a simpler operation called a proximal advancement may be done that does not require a graft.

What happens after surgery?

The supervised program of physical therapy begins the day after surgery. The program lasts for several months, with the majority of exercises done at home or in a fitness facility. Our highly skilled physical therapy team guides the patient through the different phases of the program, which have been developed through years of research and experience. It is crucial that the patient follow the guidelines in order to have the best possible chance for a successful outcome.

Our research studies have documented very low complication rates following posterolateral reconstructive procedures, which are in part due to the initiation of immediate knee motion and muscle strengthening exercises. Our comprehensive postoperative rehabilitation program may be found by clicking here.

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