Anterior Cruciate Ligament Treatment Options

Anterior Cruciate Ligament Treatment Options

So you’ve just tore your ACL…

What needs to be mentioned is that there are many treatment avenues for an ACL (anterior cruciate ligament) tear. Moreover, there is no stringent guidelines on when you need to participate in these treatment methods; and the timing of these protocols/protocol progression remains loose.

But know what the ACL is first. The ACL is one of the main stabilising ligaments in the knee. It crosses over the posterior cruciate ligament (PCL) to stabilise the knee, especially during rotation, sidestepping, and pivoting movements. The feeling of the removal of an ACL (ruptured), feels like gross instability. In an acute presentation, a ruptured ACL will test positive on an anterior draw, lachman’s and functional hop test.

Treatment for ACL tears can be dichotomised into two groups: conservative management and surgical management. Conservative management involves the strengthening of adjacent knee stabilising muscles in lieu of a functionable ACL. If at core, ACL injuries are caused by ‘excessive loading of quadriceps forces, combined with mild flexion (20 – 30 degrees), valgus or varus strain with insufficient hamstrings muscle co-contraction forces, especially when the knee is at near-extension or hyperextension’, then reconditioning will target:

  • Range of motion exercises and acute inflammation management.
  • Reduction of fibrotic growth
  • Proprioception
    • Gradual static loading of other ligaments (MCL LCL and PCL) to accustom to the new lack of proprioception that was once in the ACL.
    • Gradual safe biokinematics to test and practice golgi tendon reflex.
  • Strengthening of adjacent muscles around the knee
    • Eccentric hamstrings to cope with activities of daily living/abrupt deceleration tasks (walking, jogging, running and eventually more dynamic complex sequences of tasks).
    • Strengthening of quads and calves that roll over the knee joint capsule facilitate by holding together the knee and maintaining optimal knee alignment during athletic performance.
  • Return to sport.

Pros and cons of conservative management.


  • Non delayed onset of osteoarthritis that is associated after opening the joint capsule
  • ability to return to sport as there is no objective functional difference 5 and 10 years follow up (compared to surgery)
  • less financial burden (compared to surgery)
  • nil post surgical complications (interference screws/hardware complications, fibrotic changes post op)
  • potentially quicker return to sport (as there is no associated surgical delays and no surgical rehab required)


  • Increase risk and incidence of meniscal tears due to slackening of knee arthrokinematics if conservative treatment is inadequate (also poses greater risk for the injuring of other adjacent ligaments). I.e the loss of meniscal integrity, increased frequency of buckling
  • More difficult to return to sport (as previously the ACL is used to house proprioceptive cells)

While it is unlikely that a recreational athlete will be able to return to sport through conservative management only, it is proven that even professional athletes can return to their professional field without an ACL. Moreover, conservative management is recommended to the elderly and those who are physiologically unable to tolerate surgery or surgical procedures. A conservative recommendation for conservative management views that this intervention is fit for those who can nearly guarantee that they will benefit from arthrokinematic laxity in their knee and will not participate in dynamic movement such as cutting/pivoting activities.

So what about surgical intervention?

‘Operative treatments are based around a procedure called an ACL reconstruction. This

surgery involves replacing the damaged ligament with a new ‘graft’. Usually the hamstring

tendons (from the same leg) are used to make a new graft and via a special technique the

graft is placed across the knee and secured in the femur and tibia by screws and buttons.

This stabilises the knee. Postoperatively there is a big commitment to rehabilitation and

further physiotherapy for up to 9-12 months to see the maximum benefit from the surgery.’ (NHS 2019)

The aforementioned points for conservative reconditioning post ACL tear applies for post ACL reconstruction. The only difference of surgical and conservative is that when you opt for surgery, you need to go through the second hurdle of regaining range of motion and starting from scratch as an acute injury. However, as reconstruction takes a semitendinosis (hamstring tendon) or a patellar graft to be reinserted back into the femoral tunnel In place of the ACL, you will wake up after surgery with ‘knee confidence’ and the cessation of that empty, unstable, void feeling associated with no ACL. All patients should also know that the composition of a substitute graft ACL have different compositions to your original ACL (85% Type I collagen and 15% Type III/all other collagen) meaning that the integrity of that graft is also weaker than that of a normal ligament. The reinjury rate suggests that 17.4% of patients (athletic and non-athletic) that undergo an ACL reconstruction risk having that 2nd graft fail/tear.

The indications for ACL surgery include:

  • Having full range of knee movement prior to surgery
  • lack of pre-operative motion risk factor for post-operative arthrofibrosis
  • younger demographic <35
  • more athletic demographic (recommended that >40 is inclined for repair if sporty)
  • partial/single bundle tears with clinical and functional instability
  • prior ACL reconstruction failure

The pros and cons for surgical intervention are as follows:


  • decrease in gross instability
  • more guided approach towards return to sport + participant confidence – however return to sport previously held consensus is no sooner than 9 months following surgery.
    • Arundale et al suggests one year after ACL reconstruction 95% had returned to sport, 78% at their preinjury level. Two years after ACL reconstruction all athletes had returned to sport, 95% at their preinjury level and only one athlete had a second ACL injury.


  • surgical complications
    • Graft complications and mismatch
    • Interference screw inflammation
    • Septic arthritis and infection
    • Reduced range of motion and arthrofibrosis
    • Patella rupture
    • Patellar fracture
    • Late osteoarthritis
    • Nerve irritation and Neuropraxia (seldom reported common peroneal nerve involvement – itchiness and or numbness)
    • Growth of cysts and plicae injuries
  • Increased and elongated muscle atrophy
  • Functional deficits and nil return of normal biokinematics
  • Lower psorts participation and fear avoidance
  • Increase risk of knee reinjury
  • Financial burden
  • Near guaranteed decrease in knee hyperextension and potentiall flexion

The list of cons and potential complications also arises out of the following issues. The most important points being the first two regarding the timing of the surgery.

Complication Clinical effect Prevention Detection Remedy
Performing surgery too soon after injury [2026] Postoperative stiffness Postpone surgery until full extension and 90° flexion are attained Poor motion postoperative Aggressive physical therapy; manipulation under anesthesia +/− arthroscopy
Performing surgery too late [628] Damage to the meniscus and articular cartilage may result from persistent instability Patient education regarding limited activities; informed consent for nonoperative treatment; bracing MRI may detect disorder if recurrent instability has occurred Treat lesions as they arise
Incorrect diagnosis: MRI or preoperative examination is falsely positive [24] Removing an intact ACL and replacing it is clearly harmful to the patient Careful history and examination; consider differential diagnosis (ie, quadriceps insufficiency); high resolution MRI with musculoskeletal radiologist Thorough examination under anesthesia (ie, pivot shift, Lachman test); intraoperative observation and assessment of integrity Abort reconstruction and treat the underlying diagnosis
Missed additional diagnosis: MCL/medial capsule injury [30] Persistent pain and valgus instability may result with ultimate failure of the ACL reconstruction Careful history and examination with valgus stress at 0° and 30° flexion and anterior drawer with external rotation;scrutinize MRI Persistent valgus laxity at 0° and 30° flexion; presence of anteromedial rotatory instability; ACL reconstruction failure Bracing MCL injuries early to promote healing; surgical repair versus reconstruction, capsular plication
Missed additional diagnosis: posterolateral corner injury [23] Persistent varus instability and development of a varus thrust with ultimate failure of the ACL reconstruction Careful history and examination with varus stress at 0° and 30° flexion; scrutinize MRI Varus laxity at 0° and 30° flexion; presence of posterolateral rotatory instability with dial test Surgical repair versus reconstruction of the damaged structures
Missed additional diagnosis: meniscal tear [12] Persistent posterior joint line pain after ACL reconstruction Careful history and examination; MRI to assess coronal and sagittal sequences; posteromedial portal for complete observation and Gillquist view (Fig. 1) Postoperatively noted by persistent joint line pain and mechanical symptoms Meniscal repair for red-red and red-white tears versus meniscectomy for complex/ irreparable tears

There is also a loose consensus on the timing of ACL tears. As shown above there are clearly associated risks for missed timings. Conflicting evidence posits some of the following:

  • Surgery be performed at least 3 weeks after injury in order to avoid arthrofibrosis
  • After careful consideration of perioperative swelling, edema, hyperthermia, and range of motion should surgery be performed
    • Eitzen et al found that patients with quadriceps strength deficits greater than 20% prior to surgery had significantly greater deficits in strength two years following surgical intervention
    • Suggestion that surgery be performed only when involved quadriceps muscle strength is 80% of the uninvolved lower extremity.

However when following the last point, it would not be feasible to achieve and set up the equipment to measure 80% strength. As a timeframe, performing surgery within the next 1 – 2 years of injury will allow for a successful surgical recovery and return to sport (this means that if you are to go through a waiting list of 1 year through the private sector, your success in return to sport will not be compromised). This window also allows to see if the patient may cope with conservative treatment alone. Please also note that many victims will opt for private surgery within 3 – 9 months of their ACL tearing.

The pace of returning to sport is also contingent on how well you can participate in your rehab protocol. As range of motion post surgery is very limited, the initial aim is to get through the first 6 – 8 weeks with a graft that remains tight, but with near full extension of the knee, and minimal swelling. It should also be worth mentioning that the graft is dead and must undergo a process of revascularisation whereby a new blood supply grows into it. As the ends heal into the bone, new blood vessels start to progress down the graft. They initially appear on the surface, but eventually move into the depths of the graft as well. This process begins as early as the first week, and continues to occur out until about 18 months. However, the graft significantly weakens at 3 months where there is a drastic fall in vascularisation of the graft post reinsertion leading to increased risk of re-tearing the graft.


Therefore in the meantime, if you have torn your ACL, its is best to retrieve an MRI in confirmation of the physical findings your physician has addressed. Within the early acute stages of ACL tears, it is important to consider these treatment plans and potential prognosis (at least 1 – 2 years depending on dedication and athletic ability for each conservative and surgical, earliest 9 months).

In the meantime, treatment of your injury includes the following:

  • rest (+/- crutches)
  • elevation
  • regular ice packs ( 2 – 3 times a night for 15 mins)
  • anti-inflammatory medication and rubs
  • simple painkillers (NSAIDS)
  • compression (tubigrip for 8 – 10 hours)

Pre surgical and early conservative management should also be considered. Across a 3 – 4 week program, it would be idea to reach:

  • reduction of quad and hamstring atrophy
  • decrease in 50 – 70% (or higher) gross inflammation
  • increase in range of motion (passive range of motion to full flexion and extension)
  • Achieve a brisk walk
  • achieve graded functional but not abrupt deceleration and acceleration, and turning.

As for your knee injury, if you have not achieved full range of knee flexion and extension without pain, it is important to focus on these exercises (for 3 – 5 sets a day for 15 – 20 reps). Please use pain as a guidance, we do not want to be aggravating anything greater than 3/10 pain and of discomfort or a lack of confidence.

  • Static quad sets
  • Heel slides
  • Straight leg raise
  • Very inner range squats (with a high chair)
  • Heel raises/calf raise in standing
  • Hip abduction, extension and flexion in standing

When you are able to achieve more knee flexion (telling when you’re able to progress heel slides) you may progress to these exercises provided that your gross instability or pain is not compromised. It is vastly important to be mindful that gross instability potentiates further ligament and meniscus injuries.

  • Sit to stand on a chair
  • Static low grade forward lunges
  • Bridging with abduction band
  • Clam exercise
  • Knee flexion in standing. Nil weight hamstring curls.
  • Graded approach back to brisk walking
  • Nil resistance side walks
  • Knee extension
  • Terminal knee extension.

Written by Joshua Shum Physiotherapist 

Posted in Uncategorized.