Anterior Cruciate Ligament surgery (ACL)
A ligament is a short strip of fibrous connective tissue made out of long collagen molecules. It is an extremely strong structure that ties the bones together within the joints. Ligaments control joints’ movements. They protect the joint in case of forced movements during a sprain. There are four main ligaments involved in the knee area: two lateral ligaments (internal lateral ligament and external lateral ligament) on each side of the knee, and two central ligaments called “cruciate,” as they cross in the middle of the knee: the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL).
The ACL is usually damaged following torsion or hyperextension. Patients may feel a snap, followed by swelling and unsteadiness of the knee. ACL lesion diagnosis is made based on knee examination and laxity measurements. These measurements are conducted using a device (arthrometer or GeNouRoB) or dynamic X-rays. Devices like the arthrometer (manual measurements) or the GeNouRoB (computerized measurements) measure the anterior displacement according to strength, compared to a healthy knee.
When the anterior cruciate ligament is damaged, this displacement is increased, reflecting an ACL injury. MRI helps visualizing the ACL rupture, but “false negatives” and “false positives” do exist. The MRI is mainly useful to assess the meniscal lesions.
3/ Suitability for surgery
In order to avoid accidents due to unsteadiness while playing sports, the surgeon and his patient will take the decision to operate on ACL, depending on different factors such as age, the intensity of physical activity, and associated professional duties. Episodes of unsteadiness can lead to a secondary tear of the meniscus, which, combined with the cruciate ligament rupture, is conducive of osteoarthritis. Early ACL reconstruction helps avoiding these secondary meniscal lesions, which is crucial in young patients.
We can distinguish three groups of patients:
– Young and active patients, for whom immediate ACL reconstruction is the best option, given the high risk of unsteadiness and meniscal lesion;
– Older and moderately active patients, who should have physiotherapy first, and only undergo surgery in the event of later unsteadiness;
– An “intermediate” group of patients will have their treatment decided according to their activity needs as well as their professional and personal duties. Some will be administered physiotherapy and only undergo surgery in case of later unsteadiness, while others will undergo surgery right away.
A short period of rehabilitation (a few weeks) is usually helpful prior to surgery, in order to prepare the knee in case of severe pain, stiffness, and swelling. On the other hand, when severe injuries to the lateral ligaments accompany the cruciate ruptures, operating immediately facilitates improved healing.
4/ The surgery
The goal of this procedure is to replace the ruptured ligament, at its anatomical site, with a tendon from the same knee (autograft), without opening the joint (through arthroscopy). Taking a tendon specimen does affect the joint’s functioning. This graft is placed into the joint through small bone tunnels at the level of the tibia and the femur. This intra-articular procedure is performed under arthroscopic control, which reduces scarring and makes rehabilitation faster and less painful.
Tendon specimens are:
– Hamstrings, on the internal side of the knee. We use semitendinosus tendon (ST) and gracilis tendon(GT) They’re on the medial and posterior side of the thigh. Their very long tendons are attached to the internal side of the tibia. They can be taken through a small incision with a device called “stripper”. They are then folded double to obtain a graft with 4 strands, which is much more resistant to traction than a normal ACL.
Benefits of the STGT technique:
easier postoperative recoveries, no residual pain and higher “functional” results than the KJ.
Drawbacks: : former binding problems of these tendons have been solved using new binding modes.
- – Patellar tendon below the patella.
Also called Kenneth-Jones procedure(KJ).
The central third patellar tendon is taken out with its patellar and tibial bone attachements. It replaces the cruciate anterior ligament in the notch and the bone plugs enable a strong fixation.
Benefits of the KJ technique: as it is the oldest technique, the results are well known on the long term.
Drawbacks of the KJ technique: painful postoperative recoveries, possible persistent residual pain where the patellar tendon has been harvested, and difficulty to kneel down for 30% of patients.
For some patients (hyper laxity, repeated ACL rupture, high impact sports), an extraarticular ligamentoplasty (Lemaire’s type procedure) can be done during the same surgery, using a fascia lata band through a small incision on the antero lateral side of the knee.
In case of important rotational instability, an alternative treatment is the reconstruction of both ACL’s anatomical bundles (antero medial and postero lateral bundle) through separated femoral and tibial tunnels (double bundle reconstruction). This is a longer and more difficult technique that should only be used for specific cases.
Your questions about anterior cruciate ligament surgery
The patient can walk with crutches, which will only be needed for about 10 days depending on the recovery of the quadriceps muscle. Normal walking and driving are usually possible after 3 weeks. In case of collateral ligaments’ injury or meniscal suture, the splint should be kept at least 4 weeks. Regular physiotherapy is recommended.
The postoperative process can be summarized in four main steps:
– 1 month after surgery, normal walking and driving are possible;
– 2 months after surgery, patients can start running again;
– t3 months after surgery, patients can sprint and use lateral supports;
– 4 months after surgery, patients can resume training and high impact sports.
These periods vary depending on patients’ clinical course and several tests the surgeon perform. Training and high impact sports will only be allowed after an isokinetic evaluation shows at least 85% of muscle recovery compared to the healthy limb.
An intra-articular effusion might require draining of the knee. A hematoma on the thigh may occur, after removal of the tendon specimens. Phlebitis should be detected and treated. In some cases, there may be a strain close to where the tendon grafts were taken. Postoperative infection may occur a week after surgery; this requires cleansing of the area through arthroscopy, along with antibiotic treatment. An algodystrophy (vasomotorium disruption) can occur close to the operated area, causing pain and slowing down the rehabilitation process. It usually declines in the following months. Articular stiffness is possible, either spontaneously or resulting from the algodystrophy. Repeated rupture of the graft is possible in 2 to 3% of cases.