PCL 11 - LCL Injury Fern & Myat

Mechanism of Injury

• Force directed on anteromedial aspect of tibia with foot planted and knee in various degrees of flexion
• An LCL injury should not be confused with other overuse lateral knee injuries (eg, iliotibial band syndrome, biceps femoris tendinitis)
• Other problems:
  Meniscal tear
  Osteochondral fracture
  Biceps femoris tendiniton

Examination

History

-Ask if there is any effusion within few hours of injury. One should not expect significant effusion unless there is cruciate ligament of meniscal tear.
-If the patient also felt or heard a pop it may suggest concomitant injury
Inquire about previous injuries, symptoms, surgeries to the knee

Physical

-Inspect – gross abnormalities, skin abrasions, swelling, redness, scars etc…
-Palpate – suprapatellar pouch for effusion, joint-line tenderness
-Move
With patient lying flat and leg extended, test for medial movement of the leg at the knee joint.
More than 5 to 10 degrees is abnormal
Varus stress occurs at 0 to 30 degrees of flexion

Investigations

-X – ray to rule out fractures, dislocations, acute traumatic injuries, degenerative joint disease
-MRI to confirm diagnosis
-Electromyogram (EMG) and nerve conduction velocity (NCV) tests may assess for peroneal nerve injury.
-Arteriogram – to check popliteal artery if multiple ligaments torn
-Grade the degree of the LCL injury according to the following:

Grade 1 – Interstitial injury without laxity is present, but there is pain with varus stress; only microscopic tearing has occurred.
Grade 2 – A 5-10 mm of joint-space opening with a distinct end point is noted; partial macroscopic tearing has occurred.
Grade 3 – Complete tearing (>10 mm joint-space opening) has occurred; complete macroscopic tearing is noted.




Treatment

Grade I and II:
-RICE
-Non-bearing restrictions with use of crutches
-NSAIDs

Grade III
-Surgical intervention
-Full weight-bearing gait should return in about 4 weeks
-Rehabilitation program
-Range of movement exercise e.g. cycling, quadriceps-strengthening exercises

Surgery
-Ligament Repair
Repair of a recently torn collateral ligament usually requires an incision through the skin over the area where the tear in the ligament has occurred. If the ligament has been pulled from its attachment on the bone, the ligament is reattached to the bone with either large sutures (strong stitches) or special staples called suture anchors. Tears of the middle areas of the ligament are usually repaired by sewing the ends together.

-Ligament Reconstruction
Chronic swelling or instability caused by a collateral ligament injury may require a surgical reconstruction. Reconstruction differs from repair of the ligaments, described earlier. A reconstruction operation usually works by either tightening up the loose ligament or replacing the loose ligament with a tendon graft.

-Ligament Tightening
In the tightening procedure, your surgeon will use the remaining ligament tissue and take up the slack (similar to taking in the waist on a pair of pants). This is usually done by detaching one end of the ligament from its place on the bone and moving it so that it becomes tighter. The ligament is then reattached to the bone in the new place and held with sutures or metal staples.

-Autograft Method
if a tendon graft is needed to replace the loose ligament, it is usually taken from somewhere else in the same knee. Taking tissue from your own body is called an autograft. A common autograft that is used is one of the hamstring tendons called the semitendinosus tendon. Studies have shown that this tendon can be removed without affecting the strength of the leg. This is because other bigger and stronger hamstring muscles can take over the function of the tendon that is removed. In this operation, your surgeon will use the tendon graft to replace the damaged collateral ligament. The ends of the tendon graft are attached to the bone using large sutures or metal staples.

-Allograft Method
Another way to replace a badly torn collateral ligament is with an allograft. For this procedure, the surgeon gets graft tissue from a tissue bank. This tissue is usually removed from an organ donor at the time of death and sent to a tissue bank. There the tissue is checked for infection, sterilized, and stored in a freezer. When needed, the tissue is ordered by the surgeon and used to replace the torn collateral ligament.

Complications

-Chronic pain
-Weakness
-Instability
-Peroneal nerve injury

Prognosis

Non-surgical rehabilitation
-Minor tears should get better in 4 to 6 weeks
-Moderate tears should rehabilitate in 2 months
-Severe tears 3 months, if longer à surgery
-LCL leave knee most unstable, patients without surgery don’t usually do well

After surgery rehabilitation
-Depends on type of surgery performed
-Continuous Passive Movement:
Machine that helps the joint to move and alleviate joint stiffness
-Patients are strongly advised to follow recommendations of how much weight and -pressure they place on leg while standing or walking (usually up to 12 weeks, no weight)
-Formal exercise therapy with physical therapist