ACL injury: does it require surgery?

ACL Injury: Does It Require Surgery?

 The accompanying item furnishes in-profundity informative data about medication for front cruciate ligament damages. The general section, Foremost Cruciate Ligament Damages, gives an exceptional prologue to the theme and is prescribed perusing earlier to this piece.

The qualified information that takes after incorporates the portions of foremost cruciate ligament (ACL) life structures and the pathophysiology of an ACL tear, medicine choices for ACL wounds as well as a portrayal of ACL surgical strategies and recovery, potential complexities, and conclusions. The qualified information is planned to aid the patient in making the best equipped-educated choice feasible noticing the administration of ACL damage.


Normal knee anatomy.

The skeletal substance structure of the knee joint is framed by the femur, the tibia, and the patella. The ACL is one of the four fundamental ligaments within the knee that unite the femur to the tibia.

The knee is basically a pivoted joint that is kept as one unit by the average guarantee (MCL), parallel guarantee (LCL), foremost cruciate (ACL) and back cruciate (PCL) ligaments. The ACL runs cornerways amidst the knee, anticipating the tibia from sliding out in front of the femur, and in addition giving rotational stability to the knee.

free-quote pe

The weight-bearing surface of the knee is veiled by a layer of articular cartilage. On either side of the joint, among the cartilage surfaces of the femur and tibia, are the average meniscus and parallel meniscus. The menisci demonstration as stun absorbers and go with the cartilage to diminish the burdens in the middle of the tibia and the femur. 




The foremost cruciate ligament (ACL) is one of the most usually harmed ligaments of the knee. The occurrence of ACL wounds is right now gauged at give or take 200,000 every twelve-months, with 100,000 ACL reconstructions performed every year.1, 2 In general, the occurrence of ACL harm is higher in individuals who cooperate in heightened-hazard dons, for example court ball, football, skiing, and soccer.

Give or take 50 percent of ACL damages happen in combo with harm to the meniscus, articular cartilage, or different ligaments. Moreover, patients may have wounds of the skeletal substance beneath the cartilage surface. These may be perceived on an attractive reverberation imaging (MRI) sweep and may demonstrate damage to the overlying articular cartilage.

(Left) Arthroscopic picture of the normal ACL. (Right) Arthroscopic picture of torn ACL [yellow star].


It is gauged that 70 percent of ACL wounds happen through non-contact mechanisms while 30 percent outcome from straight contact with a different player or object.4

The mechanism of harm is frequently connected with deceleration coupled with cutting, rotating or avoiding, cumbersome landings or out of line" play.

Numerous thinks about have indicated that female contenders have a higher frequency of ACL damage than male contenders in certain sports.3,10 It has been suggested that this is because of contrasts in physical molding, brawny unyieldingness, and neuromuscular control. Different guessed explanations for this sex-identified distinction in ACL harm rates incorporate pelvis and more level limit (leg) arrangement, built ligamentous laxity, and the impacts of estrogen on ligament properties.

Instantly following the harm, patients regularly encounter torment and swelling and the knee feels temperamental. Within a few hours following a late ACL damage, patients regularly have an expansive product of knee swelling, a misfortune of full go of movement, torment or tenderness in the joint line and inconvenience while strolling.

Doctor Examination

MRI of complete ACL tear. The ACL fibers have been disrupted and the ACL appears wavy in appearance [yellow arrow].

When a patient with an ACL damage is at first viewed for assessment in the center, the specialist may request X-flashes to search for any feasible cracks. He or she might in addition request an attractive reverberation imaging (MRI) sweep to assess the ACL and to check for confirmation of harm to different knee ligaments, meniscus cartilage, or articular cartilage.

Notwithstanding performing exceptional tests for distinguishing meniscus tears and damage to different ligaments of the knee, the medical practitioner will regularly perform the Lachman's test to see if the ACL is sound. Lachman's Test movie (AAOS)

free-quote pe


Depending on if the ACL is torn, the analyst will feel built advance (upward or foremost) development of the tibia in connection to the femur (in particular when contrasted with the typical leg) and a non-abrasive, soft endpoint (resulting from the fact that the ACL is torn) when this development finishes. Lachman's Test motion picture (UMN)

An additional test for ACL harm is the turn movement test. Turn Movement Test film (AAOS) In this test, if the ACL is torn, the tibia will begin advance when the knee is thoroughly straight and afterward will movement again into the right position in connection to the femur when the knee is twisted past 30 degrees.22 Rotate Movement Test movie (UMN)


Natural History

Arthroscopic picture of torn medial meniscus in chronically ACL-deficient knee. In this case, the torn meniscus is pushed forward [yellow star] and locked in front of the knee [called a "bucket handle" meniscus tear], so the patient could not straighten out the leg.

The expected history of an ACL damage without surgical intercession differs from patient to patient and hinges on the patient's action level of damage and flimsiness symptoms.

The guess for a somewhat torn ACL is regularly great, with the recuperation and recovery period typically at slightest a few months. Be that as it may, some patients with fractional ACL tears may still have insecurity symptoms. Close clinical accompany-up and a complete course of non-intrusive treatment makes recognize the aforementioned patients with shaky knees because of fractional ACL tears.

Finish ACL breaks have a considerably less positive result. Following a complete ACL tear, some patients are unable to cooperate in cutting or rotating-sort dons, while others have flimsiness in the midst of even ordinary actions, for example strolling. There are some uncommon people who can partake in games without any symptoms of shakiness. This variability is identified with the severity of the first knee damage, and also the physical requests of the patient.

Arthroscopic picture of damaged articular cartilage in chronically ACL-deficient knee.

About part of ACL damages happen in fusion with harm to the meniscus, articular cartilage or different ligaments. Auxiliary harm may happen in patients who have rehashed scenes of flimsiness because of ACL harm. With constant shakiness, up to 90 percent of patients will have meniscus harm when reassessed 10 or more years following the beginning harm. Correspondingly, the pervasiveness of articular cartilage injuries expands up to 70 percent in patients who have a 10-year-old ACL deficiency.

free-quote pe



Nonsurgical Treatment

In nonsurgical treatment, progressive physical therapy and rehabilitation can restore the knee to a condition close to its pre-injury state and educate the patient on how to prevent instability.This may be supplemented with the use of a hinged knee brace. However, many people who choose not to have surgery may experience secondary injury to the knee due to repetitive instability episodes.

Surgical treatment is usually advised in dealing with combined injuries (ACL tears in combination with other injuries in the knee). However, deciding against surgery is reasonable for select patients. Nonsurgical management of isolated ACL tears is likely to be successful or may be indicated in patients:About part of ACL harms happen in combination with mischief to the meniscus, articular cartilage or special ligaments. Helper mischief may happen in patients who have repeated scenes of instability due to ACL damage. With unwavering instability, up to 90 percent of patients will have meniscus mischief when reassessed 10 or more years accompanying the starting damage. Correspondingly, the pervasiveness of articular cartilage wounds develops up to 70 percent in patients who have a 10-year-old ACL deficiency.

  • With partial tears and no instability symptoms
  • With complete tears and no symptoms of knee instability during low-demand sports who are willing to give up high-demand sports
  • Who do light manual work or live sedentary lifestyles
  • Whose growth plates are still open (children) 

Surgical Treatment

ACL tears are not usually repaired using suture to sew it back together, because repaired ACLs have generally been shown to fail over time.

 Therefore, the torn ACL is generally replaced by a substitute graft made of tendon. The grafts commonly used to replace the ACL include:

  • Patellar tendon autograft (autograft comes from the patient)
  • Hamstring tendon autograft
  • Quadriceps tendon autograft
  • Allograft (taken from a cadaver) patellar tendon, Achilles tendon, semitendinosus, gracilis, or posterior tibialis tendon

Patients treated with surgical reconstruction of the ACL have long-term success rates of 82 percent to 95 percent. Recurrent instability and graft failure are seen in approximately 8 percent of patients.

The goal of the ACL reconstruction surgery is to prevent instability and restore the function of the torn ligament, creating a stable knee. This allows the patient to return to sports. There are certain factors that the patient must consider when deciding for or against ACL surgery.

Patient Considerations

Active adult patients involved in sports or jobs that require pivoting, turning or hard-cutting as well as heavy manual work are encouraged to consider surgical treatment. This includes older patients who have previously been excluded from consideration for ACL surgery. Activity, not age, should determine if surgical intervention should be considered.

In young children or adolescents with ACL tears, early ACL reconstruction creates a possible risk of growth plate injury, leading to bone growth problems. The surgeon can delay ACL surgery until the child is closer to skeletal maturity or the surgeon may modify the ACL surgery technique to decrease the risk of growth plate injury.

A patient with a torn ACL and significant functional instability has a high risk of developing secondary knee damage and should therefore consider ACL reconstruction.

It is common to see ACL injuries combined with damage to the menisci (50 percent), articular cartilage (30 percent), collateral ligaments (30 percent), joint capsule, or a combination of the above. The "unhappy triad," frequently seen in football players and skiers, consists of injuries to the ACL, the MCL, and the medial meniscus.

In cases of combined injuries, surgical treatment may be warranted and generally produces better outcomes. As many as 50 percent of meniscus tears may be repairable and may heal better if the repair is done in combination with the ACL reconstruction.

Surgical Choices

Patellar tendon autograft prepared for ACL reconstruction.

Patellar tendon autograft. The center third of the patellar tendon of the patient, plus a bone attachment from the shin and the kneecap is utilized within the patellar tendon autograft. Periodically pointed to by some surgeons as the "gold standard" for ACL reconstruction, it is frequently prescribed for appeal jocks and patients whose occupations do not need a critical product of kneeling.

In inquiries investigating results of patellar tendon and hamstring autograft ACL reconstruction, the rate of joining inadequacy was easier in the patellar tendon aggregate (1.9 percent versus 4.9 percent).58 moreover, most ponders indicate meet or preferred results in terms of postoperative tests for knee laxity (Lachman's, foremost drawer and instrumented tests) when this joining is contrasted with others. On the other hand, patellar tendon autografts have a more fabulous occurrence of postoperative patellofemoral agony (ache outdated) protests and different problems.

The pitfalls of the patellar tendon autograft are:

  • Postoperative pain behind the kneecap
  • Pain with kneeling
  • Slightly increased risk of postoperative stiffness
  • Low risk of patella fracture
Hamstring tendon autograft prepared for ACL reconstruction.

Hamstring tendon autograft. The semitendinosus hamstring tendon on the inner side of the knee is used in creating the hamstring tendon autograft for ACL reconstruction. Some surgeons use an additional tendon, the gracilis, which is attached below the knee in the same area. This creates a two- or four-strand tendon graft. Hamstring graft proponents claim there are fewer problems associated with harvesting of the graft compared to the patellar tendon autograft including:

  • Fewer problems with anterior knee pain or kneecap pain after surgery
  • Less postoperative stiffness problems
  • Smaller incision
  • Faster recovery

The graft function may be limited by the strength and type of fixation in the bone tunnels, as the graft does not have bone plugs. There have been conflicting results in research studies as to whether hamstring grafts are slightly more susceptible to graft elongation (stretching), which may lead to increased laxity during objective testing.Recently, some studies have demonstrated decreased hamstring strength in patients after surgery.

There are some indications that patients who have intrinsic ligamentous laxity and knee hyperextension of 10 degrees or more may have increased risk of postoperative hamstring graft laxity on clinical exam. Therefore, some clinicians recommend the use of patellar tendon autografts in these hypermobile patients.

Additionally, since the medial hamstrings often provide dynamic support against valgus stress and instability, some surgeons feel that chronic or residual medial collateral ligament laxity (grade 2 or more) at the time of ACL reconstruction may be a contra-indication for use of the patient's own semitendinosus and gracilis tendons as an ACL graft.

Quadriceps tendon autograft prepared for ACL reconstruction.

Quadriceps tendon autograft. The quadriceps tendon autograft is often used for patients who have already failed ACL reconstruction. The middle third of the patient's quadriceps tendon and a bone plug from the upper end of the knee cap are used. This yields a larger graft for taller and heavier patients. Because there is a bone plug on one side only, the fixation is not as solid as for the patellar tendon graft. There is a high association with postoperative anterior knee pain and a low risk of patella fracture. Patients may find the incision is not cosmetically appealing.

Patellar tendon (top) and Achilles tendon (bottom) allografts prior to being prepared for ACL resonstruction.

Allografts.Allografts are grafts taken from cadavers and are becoming increasingly popular.These grafts are also used for patients who have failed ACL reconstruction before and in surgery to repair or reconstruct more than one knee ligament. Advantages of using allograft tissue include elimination of pain caused by obtaining the graft from the patient, decreased surgery time and smaller incisions. The patellar tendon allograft allows for strong bony fixation in the tibial and femoral bone tunnels with screws.

However, allografts are associated with a risk of infection, including viral transmission (HIV and Hepatitis C), despite careful screening and processing. Several deaths linked to bacterial infection from allograft tissue (due to improper procurement and sterilization techniques) have led to improvements in allograft tissue testing and processing techniques. There have also been conflicting results in research studies as to whether allografts are slightly more susceptible to graft elongation (stretching), which may lead to increased laxity during testing.

Recently published literature may point to a higher failure rate with the use of allografts for ACL reconstruction. Failure rates ranging from 23% to 34.4% have been reported in young, active patients returning to high-demand sporting activities after ACL reconstruction with allografts. This is compared to autograft failure rates ranging from 5% to 10%.

The reason for this higher failure rate is unclear. It could be due to graft material properties (sterilization processes used, graft donor age, storage of the graft). It could possibly be due to an ill-advised earlier return to sport by the athlete because of a faster perceived physiologic recovery, when the graft is not biologically ready to be loaded and stressed during sporting activities. Further research in this area is indicated and is ongoing.

Surgical Procedure

Passage of patellar tendon graft into tibial tunnel of knee.

Before any surgical treatment, the patient is usually sent to physical therapy. Patients who have a stiff, swollen knee lacking full range of motion at the time of ACL surgery may have significant problems regaining motion after surgery. It usually takes three or more weeks from the time of injury to achieve full range of motion. It is also recommended that some ligament injuries be braced and allowed to heal prior to ACL surgery.

Post-operative X-ray after ACL patellar tendon reconstruction (with picture of graft superimposed) shows graft position and bone plugs fixation with metal interference screws.

The patient, the surgeon, and the anesthesiologist select the anesthesia used for surgery. Patients may benefit from an anesthetic block of the nerves of the leg to decrease postoperative pain.

The surgery usually begins with an examination of the patient's knee while the patient is relaxed due the effects of anesthesia. This final examination is used to verify that the ACL is torn and also to check for looseness of other knee ligaments that may need to be repaired during surgery or addressed postoperatively.

If the physical exam strongly suggests the ACL is torn, the selected tendon is harvested (for an autograft) or thawed (for an allograft) and the graft is prepared to the correct size for the patient.

Arthroscopic view of ACL graft [yellow star] in position.

After the graft has been prepared, the surgeon places an arthroscope into the joint. Small (one-centimeter) incisions called portals are made in the front of the knee to insert the arthroscope and instruments and the surgeon examines the condition of the knee. Meniscus and cartilage injuries are trimmed or repaired and the torn ACL stump is then removed.

In the most common ACL reconstruction technique, bone tunnels are drilled into the tibia and the femur to place the ACL graft in almost the same position as the torn ACL. A long needle is then passed through the tunnel of the tibia, up through the femoral tunnel, and then out through the skin of the thigh. The sutures of the graft are placed through the eye of the needle and the graft is pulled into position up through the tibial tunnel and then up into the femoral tunnel. The graft is held under tension as it is fixed in place using interference screws, spiked washers, posts, or staples. The devices used to hold the graft in place are generally not removed.

Variations on this surgical technique include the "two-incision," "over-the-top," and "double-bundle" types of ACL reconstructions, which may be used because of the preference of the surgeon or special circumstances (revision ACL reconstruction, open growth plates).

Before the surgery is complete, the surgeon will probe the graft to make sure it has good tension, verify that the knee has full range of motion and perform tests such as the Lachman's test to assess graft stability. The skin is closed and dressings (and perhaps a postoperative brace and cold therapy device, depending on surgeon preference) are applied. The patient will usually go home on the same day of the surgery.

Surgical Complications


Infection. The incidence of infection after arthroscopic ACL reconstruction has a reported range of 0.2 percent to 0.48 percent. There have also been several reported deaths linked to bacterial infection from allograft tissue due to improper procurement and sterilization techniques.

Viral transmission. Allografts specifically are associated with risk of viral transmission, including HIV and Hepatitis C, despite careful screening and processing. The chance of obtaining a bone allograft from an HIV-infected donor is calculated to be less than 1 in a million.

Bleeding, numbness. Rare risks include bleeding from acute injury to the popliteal artery (overall incidence is 0.01 percent)  and weakness or paralysis of the leg or foot. It is not uncommon to have numbness of the outer part of the upper leg next to the incision, which may be temporary or permanent.

Blood clot. A blood clot in the veins of the calf or thigh is a potentially life-threatening complication. A blood clot may break off in the bloodstream and travel to the lungs, causing pulmonary embolism or to the brain, causing stroke. This risk of deep vein thrombosis is reported to be approximately 0.12 percent.

Instability. Recurrent instability due to rupture or stretching of the reconstructed ligament or poor surgical technique (reported to be as low as 2.5 percent and as high as 34 percent) is possible.

Stiffness. Knee stiffness or loss of motion has been reported at between 5 percent and 25 percent.

Extensor mechanism failure. Rupture of the patellar tendon (patellar tendon autograft) or patella fracture (patellar tendon or quadriceps tendon autografts) may occur due to weakening at the site of graft harvest

Growth plate injury. In young children or adolescents with ACL tears, early ACL reconstruction creates a possible risk of growth plate injury, leading to bone growth problems. The ACL surgery can be delayed until the child is closer to reaching skeletal maturity. Alternatively, the surgeon may be able to modify the technique of ACL reconstruction to decrease the risk of growth plate injury.

Kneecap pain. Postoperative anterior knee pain is especially common after patellar tendon autograft ACL reconstruction. The incidence of pain behind the kneecap varies between 4 percent and 56 percent in studies, whereas the incidence of kneeling pain may be as high as 42 percent after patellar tendon autograft ACL reconstruction.


Physical therapy is a crucial part of successful ACL surgery, with exercises beginning immediately after the surgery. Much of the success of ACL reconstructive surgery depends on the patient's dedication to rigorous physical therapy. With new surgical techniques and stronger graft fixation, current physical therapy uses an accelerated course of rehabilitation.

Postoperative Course. In the first 10 to 14 days after surgery, the wound is kept clean and dry, and early emphasis is placed on regaining the ability to fully straighten the knee and restore quadriceps control.

The knee is iced regularly to reduce swelling and pain. The surgeon may dictate the use of a postoperative brace and the use of a machine to move the knee through its range of motion. Weight-bearing status (use of crutches to keep some or all of the patient's weight off of the surgical leg) is also determined by physician preference, as well as other injuries addressed at the time of surgery.

Rehabilitation. The goals for rehabilitation of ACL reconstruction include reducing knee swelling, maintaining mobility of the kneecap to prevent anterior knee pain problems, regaining full range of motion of the knee, as well as strengthening the quadriceps and hamstring muscles.

The patient may return to sports when there is no longer pain or swelling, when full knee range of motion has been achieved, and when muscle strength, endurance and functional use of the leg have been fully restored.

The patient's sense of balance and control of the leg must also be restored through exercises designed to improve neuromuscular control. This usually takes four to six months. The use of a functional brace when returning to sports is ideally not needed after a successful ACL reconstruction, but some patients may feel a greater sense of security by wearing one.