proceduresACL Reconstruction

Anterior Cruciate Ligament (ACL) Reconstruction

As an experienced Orthopaedic Sports Surgeon I have treated all types of athletes - young and old, world class and amateur, with ACL injuries. This article will help you make the most-informed decision possible regarding the management of an ACL injury.

What is an ACL tear?
Most patients I meet have heard of the ACL, and know athletes that have suffered an ACL tear, but are not exactly sure what or where it is. ACL stands for Anterior Cruciate Ligament. It is one of the main ligaments (rope like structure) in the knee.

The ACL sits in the middle of the knee and attaches the thigh bone (femur) to the shin bone (tibia). It stops the shin bone from sliding forward and rotating excessively. If your ACL is torn then your knee may buckle and give way during movements that require a sudden change in direction, like sidestepping or pivoting, e.g. during football, basketball, netball, rugby or martial arts.

Most patients that I see that I see with an ACL tear have had a non-contact injury that occurred when they were turning on their knee suddenly during training or a match. In footballers this can occur when they place excessive pressure on their standing leg when performing a crossfield pass.

Unfortunately for female athletes reading this, you are at greater risk for an ACL tear, due to differences in alignment, size and shape of your knees.

Athletes who tear their ACL often feel a ‘pop’ and their knee may swell suddenly (as the torn ligament bleeds). A key feature is that they are immediately unable to walk or continue playing due to pain. When the knee swelling eventually subsides their knee may feel unstable or even give way, and they are unable to play their favourite sports.

I always ask a lot of questions about how exactly the injury occurred and carefully examine the knee to make the diagnosis of an ACL tear. An MRI (magnetic resonance imaging) scan can swiftly be arranged to identify an ACL tear and rule out other injuries such as a meniscal tear.

Famous athletes who have suffered an ACL tear include Zlatan Ibrahimovich, Ruud Van Nistelrooy, Francesco Totti, Paul Gascoigne, Alan Shearer, Tom Brady, Tiger Woods, Jamal Crawford, and Derrick Rose to name but a few. So if you have an ACL tear then you are in excellent company, and the good news is that all these athletes were able to resume their playing careers successfully after an ACL reconstruction. With the right treatment so can you!

Can the torn ACL heal on its own?
The ACL usually does not heal well on its own because it does not have a good blood supply. I liken it to a rope, and if completely torn in the middle, it is difficult for the rope ends to come together to heal, particularly as the knee is moving all the time. However some athletes are able to return to sports if they only have a partial ACL tear, minimal instability or play sports that do not involve sudden turning movements (e.g. baseball).

Is ACL reconstruction surgery my only treatment option?
ACL reconstruction is when the torn ACL is completely replaced by a tissue “graft” (usually made of hamstring tendons which sit behind the inner thigh) to provide stability to the knee. It is the recommended treatment option for athletes who have knee instability following an ACL tear, and are unable to play sports.

It is worth seeing a good physiotherapist on the recommendation of your surgeon, and undergo rehab before considering surgery. This allows your knee to regain full range of movement and strength, as well as allow bone bruising to settle. Some doctors have also argued that ACL reconstruction is associated with a lower risk of early arthritis (degenerative change) on Xray.1

ACL repair is a newer treatment suitable for certain types of tears where the ends of the torn ACL are reattached to the thigh bone using a device called an internal brace. Most ACL tears are not suitable for direct repair and there can be a high rate of revision surgery with repair (1 in 8 patients in some papers). There are many studies on the use of stem cell and platelet rich plasma in ACL healing, but these technologies are still in an experimental stage and the “gold standard” treatment is still ACL reconstruction surgery.2

Who can benefit most from an ACL reconstruction surgery?
I recommend ACL reconstruction for patients with knee instability and:
  • Active adult patients involved in sports requiring pivoting or turning.
  • Active adult patients with jobs, particularly heavy labour, requiring pivoting or turning
  • Older patients (e.g. above 50) who compete at an elite level and do not have degenerative change in their knees
  • Children or adolescents with ACL tears - a modified technique can be used to reduce risk of injury to the growth plate.
  • Athletes with other injuries to their knees as well as ACL tear –ligaments such as the PCL (posterior cruciate ligament) LCL (lateral collateral ligament), menisci and cartilage. Particularly for some meniscus tears, a better result can be had if the repair is done at the same time as an ACL reconstruction

What are the different types of ACL reconstruction surgeries in Singapore?
All reconstruction surgeries use a ‘graft’ or transplanted tissue, to replace the torn ACL. These grafts include:

  1. Hamstrings tendons – these are easily harvested from the inside of the knee during surgery using a small incision (autograft). Alternatively donated tendon can be used to replace your torn ACL (allograft). Athletes who have very flexible joints (hyperlaxity), a very loose MCL (medial collateral ligament) or very small hamstring tendons may be more suitable for allograft or patellar tendon graft (below).
  2. Patellar tendon - The middle third of the patellar tendon of the patient, along with a bone plug from the shin and the kneecap is used in the patellar tendon autograft. It is effective as the hamstring tendon graft but has a higher risk of kneecap pain, particularly when kneeling, and fracture of the kneecap itself. There may also be a larger scar on the front of the knee.
  3. Medial portal vs Transtibial - When ACL reconstruction first began, surgeons drilled their bone tunnels in a straight line from the shinbone into the thighbone (transtibial). This means that the bone tunnel in the thighbone is not where the original ACL used to sit. In contrast using the medial portal technique, surgeons try and place the bone tunnels and graft as close to the original position of the ACL as possible (anatomical position). Some surgeons believe that using a transtibial technique can result in greater rotational instability of the knee and a higher revision rate.3
  4. All-inside / Graftlink Technique - The all-inside technique uses reverse drilling to reduce the amount of bone removed from the knee. It also needs only one hamstring to recreate the ACL graft. The rationale is that this technique may be more minimally invasive and less painful than conventional methods.
  5. Single bundle versus double bundle - Some surgeons try and recreate the two main bundles of the ACL by drilling 4 holes in the bones of your knee instead of 2. There is no major difference in results between single or double bundle ACL reconstruction – you can achieve an excellent result with either technique.5
  6. Growth plate preserving - Young children or adolescents with ACL injury may still have open growth plates. These fuse around age 14 in girls, and age 16 in boys. Using a standard technique for ACL reconstruction (transphyseal) may injure the growth plates and stop the bones from growing (growth arrest). Your surgeon should screen for growth plates and either wait until your child has stopped growing, or use a special technique to avoid the growth plate (Epiphyseal or extraphyseal)

When is the best time to go for an ACL reconstruction surgery after an injury?
Within a few weeks of injury is ideal.6 Delaying surgery for more than 6 months is associated with a higher risk of injury to other structures in the knee like cartilage and menisci.7,8 Ideally you will have undergone physiotherapy to reduce swelling, regain full range of movement and strengthen your quadriceps (front thigh muscles) before the operation.

What happens during an ACL reconstruction surgery?
  • You will have an anaesthetic and go to sleep during surgery.
  • I make 2 small keyhole incisions at the front of the knee, and another small one on the inside to harvest your hamstrings to replace your ACL. This procedure is minimally invasive.
  • I then inspect the knee thoroughly with a camera (arthroscope), and drill small tunnels in the thigh bone and shin bone where the ACL normally sits.
  • The placement of these tunnels is important to achieve a good result
  • I then pass the hamstring graft through the tunnels and secure it with a metal button and plastic screw.
  • The whole procedure takes around an hour.
  • You will be able to walk the same day after surgery with crutches.
  • In the UK and Australia where I trained, most patients can go home on the same day of surgery.
What is the recovery process like after an ACL reconstruction surgery?
  • After the surgery the knee is sore, but you’ll be given some strong painkillers.
  • You’ll be able to get up and walk straight after the surgery, with crutches
  • Some patients are well enough to go home the same day
  • It’s important to start physiotherapy soon after the operation
  • You may be on crutches for up to six weeks
  • You can return to office based work after 2 weeks.
  • If you have a physically demanding job it will take longer before you can return
  • Return to sports can be anything from 6-12 months, usually 9 months

Some people recover quickly, some take a little longer. For a professional athlete it can be at least a year before they return to sports at a similar level. If you return to sport too soon you have an increased risk of your ACL graft retearing.

How much improvement can you expect after an ACL reconstruction surgery?
According to a large study involving 7556 patients undergoing ACL recontructsion, the majority were able to return to sports (81%). Two thirds of all patients were able to return to their preinjury level of competition, and 55 percent were able to return to elite level competition.

Summary
If you have torn your ACL and have knee instability, ACL reconstruction may be an excellent solution to your problems. At International Orthopaedic Clinic (IOC) we are dedicated to helping you find your way back to playing and enjoying sports.

References:
  1. Jomha NM et al. Long-term osteoarthritic changes in anterior cruciate ligament reconstructed knees. Clin Orthop Relat Res. 1999 Jan;(358):188-93.
  2. Mahapatra P et al. Anterior cruciate ligament repair – past, present and future J Exp Orthop. 2018 Dec; 5: 20. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6002325/
  3. Duffee A et al. Transtibial ACL femoral tunnel preparation increases odds of repeat ipsilateral knee surgery. J Bone Joint Surg Am. 2013 Nov 20;95(22):2035-42
  4. Sprowls GR, Robin BN. The Quad Link Technique for an All-Soft-Tissue Quadriceps Graft in Minimally Invasive, All-Inside Anterior Cruciate Ligament Reconstruction. Arthrosc Tech. 2018 Jul 16;7(8):e845-e852.
  5. Mayr HO et al. Single-Bundle Versus Double-Bundle Anterior Cruciate Ligament Reconstruction-5-Year Results. Arthroscopy. 2018 Sep;34(9):2647-2653.
  6. Manandhar RR et al. Functional outcome of an early anterior cruciate ligament reconstruction in comparison to delayed: Are we waiting in vain? J Clin Orthop Trauma. 2018 Apr-Jun;9(2):163-166.
  7. Kay J et al. Earlier anterior cruciate ligament reconstruction is associated with a decreased risk of medial meniscal and articular cartilage damage in children and adolescents: a systematic review and meta-analysis. Knee Surg Sports Traumatol Arthrosc. 2018 Jun 6
  8. Taketomi S et al. Surgical timing of anterior cruciate ligament reconstruction to prevent associated meniscal and cartilage lesions. J Orthop Sci. 2018 May;23(3):546-551
  9. Ardern CL et al. Fifty-five per cent return to competitive sport following anterior cruciate ligament reconstruction surgery: an updated systematic review and meta-analysis including aspects of physical functioning and contextual factors. Br J Sports Med 2014; 48:1543.
Feeling Pain from Your Injuries?

Dr Alan Cheung is a Consultant Orthopaedic Surgeon specialising in Sports Injuries such as torn ligaments and tendons, and cartilage injury in the knee, hip and shoulder, Adult Joint Reconstruction including total and partial Knee Replacement and Total Hip Replacement for osteoarthritis, and Robotic Surgery (Makoplasty, Navio and Robodoc systems). He has also received extensive training in trauma (fixing broken bones) and musculoskeletal tumour (bone cancer) surgery.

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