The knee joint is made up of three bones – femur, tibia and patella. It is a very complex joint that has the function of maintaining stability as well as mobility. There are various ligaments surrounding the knee joint whose function is to provide stability to the joint and one of them is the anterior cruciate ligament. The anterior cruciate ligament is completely stretched during extensions and hyperextension of the knee and thus aids in checking hyperextension of the knee. This type of injury is usually seen in athletes.
Mechanism of injury includes – cutting or changing the directions when the knee is flexed or hyperextension of the knee or valgus forces with external rotation of the tibia or internal rotation of the femur.
Clinical features usually include: pop or snap type of sound during injury
- Intense pain and the patient cannot flex his leg.
- Tenderness usually on the lateral side of the knee
- Increased anterior tibial translation
- Reduced muscle strength
Usually in grade 1 and grade 2 types of ACL injury a conservative approach is usually preferred where the main focus is to reduce pain and swelling and further increase the strength of the muscles mainly the quadriceps and the hamstrings.
For grade 3 types of tear usually ACL reconstruction is preferred which is an operative procedure. The rehabilitation of the patient after an operative procedure is divided into three phases:
- Acute ( from 0 to 4 weeks)
- Sub-acute (from 4 to 8 or 10 weeks)
- Return to activity phase (from 10 weeks )
Bracing is an important thing that is prescribed to the patients undergone surgical management as well as conservative management. Patients are instructed to wear a knee brace that keeps the leg in extension and helps keeping the leg immobilized.
For pain relief usually preferred modalities are – Transcutaneous electrical nerve stimulation (TENS) , LASER are preferred.
Open chain exercises are usually preferred in the acute phase then starting with close chain exercises to incorporate quadriceps into a dynamic movement.
The strength of the lower extremity musculature is to be increased in the second phase which is done by manual resistance or mechanical resistance which can be provided by weight cuffs, Therabands, sandbags etc.
Strength training should focus on both strength and muscle endurance so the weight should be increased progressively from 8 to 10 repetitions to 15 repetitions and 3 sets and further.
Balance is also affected due to ACL injury and to improve balance perturbation training is given which is usually started from a stable surface and then progressed to a dynamic surface like a wobble board.
Total rehabilitation time for an athlete till he can get back to his sport is usually 8 to 9 months where in the last phase of rehabilitation the main focus is on plyometric, agility etc.
Cycling, jogging, running etc is advised after 2 months of the surgery which is approx. 8 weeks from the date of operation.