ANTERIOR CRUCIATE LIGAMENT TEAR

ACL tear is beginning of end of knee. ACL tear is common in contact sports, falls and dashboard injuries. There are grades of ACL tear. Extent of ACL tear and damage to other supporting structures are the factors determining instability.
Mechanics of ACL tear
1) External rotation and abduction strain on flexed knee (most common)
2) Complete dislocation of knee
3) Dashboard injury
4) Internal rotation on knee in extension (isolated tears)

Clinical features
Acute episode:
1) There is buckling or giving away of knee
2) Audible pop is heard
3) There is severe pain with difficulty in walking.
4) Swelling within 2 hours suggests haemarthrosis. Overnight swelling may be due to acute traumatic synovitis.

After the acute episode subsides. There may be flexion deformity due to hamstring spasm. Patient complains of
giving away. By definition, chronic injuries refer to instabilities that still exist 3 months after acute episode.

Signs:
There is wasting of quadriceps. Flexion attitude of knee is possible due to hamstring spasm.
ACL tear can be associated with collateral and meniscal injury.
ACL injury is associated with instability.

Anterior Drawers test
The manoeuvre tests adequacy of ACL. Knee is kept at 90 degrees and hip at 45 degrees. Patient’s foot is stabilised.
Upper end of tibia is grasped and glided anteriorly.
Abnormal displacement of 5 mm means test is positive. If there is associated medial or lateral subluxation, it
indicates rotary subluxation.
The same test can be repeated by internal rotation, which touts posterior cruciate. However if still there is anterior
Translation, PCL also is torn.

Lachman’s test
This test can be done in swollen and painful knee. It negates effect of medial meniscus. Knee is kept at 15 degrees of flexion with slight external rotation. Thigh is stabilised with one hand. Leg is held by other hand. Anterior translation with mushy feel makes test positive.

Lateral Pivot Shift of McIntosh
This manoeuvre tests functional integrity. With, knee extended, leg is internally rotated. Valgus stress is given at knee. This makes tibia to subluxate anterior. As the knee is flexed, the illiotibial band passes posterior and provides force that reduces lateral tibial plateau on femur.

Investigations
Radiographs are usually negative. Some times , radiographs give indirect evidence of ACL tear. Lateral views might show avulsion of intercondylar eminence.
Lateral capsular sign: small fragment along joint line suggests capsular avulsions.
Stress tests are done in children with suspected physeal injuries.
MRI shows clear and accurate images of ligaments and menisci. PCL is more straight can be seen better, ACL can be viewed with non orthogonal cuts.
Arthroscopy can be used for diagnosis as well as for treatment.

Treatment
ACL tear is described as beginning of end of knee. Hence, active young athletic man with ACL tear requires surgery.
Indications:
1) Athletic male
2) Associated injuries, instabilities
3) Avulsion fracture

Because of relative avascularity and unpredictable healing, reconstruction of ACL is preferred to repair.
Certain criteria’s are considered before ACL recon. Meniscal injuries needs to be settled. Integrity of other ligaments should be considered. ACL reconstruction gives good results when articular cartilage is healthy.
Post reconstruction ACL reconstruction protocol physiotherapy is of utmost importance.
Physiotherapy is given to improve strength of secondary stabilizers like quadriceps, hamstrings and hip muscles.
Click on this link to know details of ACL RECON PHYSIO.

Types of Reconstructions
1. Extra articular reconstruction is basically of two types. Creation of static check reins by tightening of medial/lateral structures. Creation of dynamic force that acts on tibia to prevent its displacement by powerful quadriceps. They suffice for mild instability.
Modalities
1) McIntosh : Lateral reconstruction using illiotibial band
2) Andrews : Double ligament reconstruction using illiotibial band


2. Intraarticular reconstructions replace ACL.
3. Combined

Concept of Notchplasty
ACL courses at angle of 40 degrees from anteroinferior attachment to its posterosuperior femoral attachment. A narrow intercondylar notch rubs against ACL. Narrowed notch with presence of osteophytes accentuate this.
Hence notchplasty (deepening and widening of notch by 2mm) is done to avoid impingement and reduce chances of rupture.

Modified Jones (Clancy) procedure
Modified Jones (Clancy) procedure is commonly used. Patellar bone tendon bone graft is used for reconstruction.
It is very popular because of rapid healing and strength. The procedure can be done either open or arthroscopic.

Other Procedures
Lipscomb procedure (Semitendinosus and gracillis detached from musculotendinous junction)
Puddu procedure (Semitendinosus and gracillis detached from tibial crest)
Zariczny’s procedure (loop or double thickness Semitendinosus)
Zarin and Rowe procedure
This procedure is done for severe instability. It combines both extaarticular and Intraarticular. Illiotibial band and semitendinosus tendon are used
Synthetics reconstruction ( Stryker Dacron or Gore Tex are used)


Click on this link to know details of ACL RECON PHYSIO.