ACL injury

ACL rehabilitation better than ACL surgery intially.

Only in persistent instability after adequate rehabilittation should surgery be advised.

Many footballers have suffered recently from cruciate knee injuries.

It results in a lengthy period on the sidelines, but why is it so serious?


There are four main ligaments in the knee - one on either side and two across the middle.

Medial collateral ligament (MCL)

Lateral collateral ligament (LCL)

Anterior cruciate ligament (ACL)

Posterior cruciate ligament (PCL)

The ACL is behind the kneecap (patella) and is in front of the PCL.

It's the second strongest ligament in the knee and stabilises the joint, connecting the thigh bone (femur) and the leg bone (tibia).

The ACL and PCL limit the over straightening, over bending and rotation of the knee.

The average length of the ACL is around 35mm, weighing around 20g.

The medial ligament is one the inside of the knee, with the lateral on the outside.


Surgery is not essential in most patients. 

Most patients recovery with good physiotherapy rehabilitation. 

Best exercises are Knee full range of exercises and normal outdoor cycling for half to one hour and or / speed walking for half hour+ stair climbing for 10 min daily.    


Rehabilitation physiotherapy is key to having stable and pain free knee. 

Only those with unstable painful knee after adequate weeks of physiotherapy would benefit from ACL reconstruction. 

ACL rehab exercises will be needed even after surgery lifelong as the new ligament will not have the same properties and strength as the natural ACL ligament.

Early ACL reconstruction may reduce the subsequent incidence of medial meniscal damage, which will influence the progression of OA, but for others, optimized rehabilitation and modification of activity will be enough.

An ACL injury markedly increases the risk of the development of OA of the knee, independent of whether surgical or nonoperative treatment is undertaken.

Therefore, patients with an ACL rupture need to be counselled appropriately, and we must redouble our

efforts to prevent these injuries. 

A middle aged or older person could recover without going under the surgeon's knife.

Surgeon's will usually graft tissue from either the patella or hamstring tendons to repair the ACL.

Basically the new tendon replaces the ACL and is usually attached to the bones above and below the knee by screws.

The success rate for such operations are good for unstable knee with the injured person can soon be up and walking, running and twisting are some months further down the line.

Snoeker BA, Roemer FW, Turkiewicz A, Lohmander S, Frobell RB, Englund M. Does early anterior cruciate ligament reconstruction prevent development of meniscal damage? Results from a secondary analysis of a randomised controlled trial. Br J Sports Med. 2020;54(10):612–617.

Webster KE, Hewett TE. Anterior cruciate ligament injury and knee osteoarthritis: an umbrella systematic review and meta- analysis. Clin J Sport Med. 2021;Epub ahead of print.

The Bone & Joint JournalVol. 104-B, No. 5 Editorial

Is the die cast? Anterior cruciate ligament injury and osteoarthritis

Vishal Rajput  Fares S. Haddad  Published Online:1 May 2022

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 persistent instability of knee after adequate rehabilitation physiotherapy exercises, cycling therapy esp in sports persons or heavy manual workers ordealing 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:

1. with partial tears and no instability symptoms39

2. With complete tears and no symptoms of knee instability during low-demand sports who are willing to give up high-demand sports

3. who do light manual work or live sedentary lifestyles

4. 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:

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.

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.4 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.


Medical expert Bevan Ellis says: "Many top athletes will go through an accelerated rehabilitation programme to get them back in action within six months.

"It requires intensive physiotherapy which needs to be monitored very closely at every stage.

Phase one (0-2 weeks after surgery)

"For a typical person, an ACL injury would normally take between 8-12 months to get back to full fitness."

The knee will be swollen after the operation, so the first job is to reduce the swelling.

After that, the physio will make the patient do a few light exercises like isometric contractions - keeping the leg still but moving the muscles around the knee.

Phase two (2-6 weeks after surgery)

The swelling should have disappeared, but the graft usually weakens around this time.

The physio may have to back off from the rehabilitation programme until the ligament is up to more exercises.

The patient should be walking normally by then.

Phase three (6-12 weeks after surgery)

By this stage, the knee should be getting stronger and able to take more strain.

The patient should be able to go swimming and use a road bike to get the knee back on track, as well as doing more strength exercises.

Phase three (3-6 months)

The patient will have their full range of movement and strength back, so they can start running properly once more.

They should be able to get back to specific drills and training.

Phase four (6-12 months)

The patient should be able to return to playing sport with their surgeon's approval.


 In this first high quality randomised controlled trial with minimal loss to follow-up, a strategy of rehabilitation plus early ACL reconstruction did not provide better results at five years than a strategy of initial rehabilitation with the option of having a later ACL reconstruction. 

Results did not differ between knees surgically reconstructed early or late and those treated with rehabilitation alone. These results should encourage clinicians and young active adult patients to consider rehabilitation as a primary treatment option after an acute ACL tear.