Yorkshire Knee Surgery - Mr A Siddiqui Consultant Knee Surgeon
Your Knees are in Good Hands...
Home/Contact DetailsCartilage problemsACL & LigamentsArthritis & Knee ReplacementKneecap problemsKnee/ACL Rehab & ExerciseVideo:Arthroscopic Meniscal SurgeryVideo: ACL reconstructionVideo: Knee Replacement
ACL & Ligaments

ACL & Ligament Injuries

The Anterior Cruciate Ligament (ACL), is one of 4 major ligaments that stabilise the knee joint. It is commonly injured in sports and skiing activities, and results in moderate swelling within a few hours of the injury.

The photo below shows the normal appearance of the ACL during a keyhole procedure on the knee. 
The photo below shows an ACL reconstruction using Hamstring graft at time of surgery and then after one year.
Secondary damage can occur to the cartilage at the time of the injury or later as the knee keeps giving way and puts extra strain on the knee joint. 

The injury usually occurs during activities such as football, rugby, skiing, squash or other twisting manoeuvres. Patients usually feel something “go” or “snap” in the knee. The knee swells within 2-4 hours usually but not always. It is important to see a physiotherapist or your doctor soon and seek referral to a specialist in ACL injuries. Early rehabilitation of the knee is targeted at reducing the swelling with Rest, Ice, Compression with a tubigrip bandage and Elevation of the leg when resting (RICE). Early efforts to regaining range of motion and quadriceps strength are also beneficial. This phase will usually improve over a few weeks. A bone bruise may be present and cause pain on weight bearing noticed with a limp, and may take a number of weeks to settle. If there is a block to extension that is not improving there may be a mechanical obstruction in the knee that could require early intervention. 

The knee may give way on a recurrent basis and if this is a problem after adequate physiotherapy, then early surgery is recommended before secondary injury to the cartilage takes place.

Reconstruction of the ACL is a highly successful procedure and is performed Arthroscopically (Keyhole) 
necessitating only 24 hours in hospital usually. 

Videos of ACL reconstruction surgery performed by Mr Siddiqui can be viewed on this website and also at:



Animation videos of ACL reconstruction can be viewed also and include Patella tendon ACL reconstruction (http://www.hipsknees.info/flash5/HTML/demo.html) and Hamstring tendon ACL reconstruction (http://www.hipsknees.info/flash4/ypo.swf).
These videos are 3rd party products and may contain facts and representations that are different from Mr Siddiqui's practice.

Typical scars after Arthroscopic ACL reconstruction. Patella tendon graft on left and Hamstring graft on right.

2 Different grafts are in common usage, the Patella Tendon (Kneecap graft), and the Hamstrings graft. Depending on patients’ pre-injury activities, occupation, and future needs, appropriate grafts are chosen for the individual. 

Patella Tendon graft shown in photo below. Note bone on each end and a soft tissue component with purple mark on in centre 


    Hamstring tendons harvested and prepared as ACL graft

    Precise surgical technique and accurate tunnel placement dictate the success of the procedure. Surgeons performing the procedure infrequently often have poor results compared to surgeons performing higher volumes of ACL reconstructions. Mr Siddiqui has surgical expertise in the procedure. He has many years of experience and has been collecting and comparatively analysing his data over this time. He adheres to the best practice guidelines produced by the British Association of Knee Surgery, UK. He is performing the largest number of arthroscopic ACL reconstructions in the hospitals in which he practices (average 80-100 per year), and revising failed surgery when appropriate. Regular auditing of results is undertaken, and in knees that have no additional cartilage injury, excellent outcomes were achieved in over 95% of cases with full return to sporting activities in the vast majority.

Xray showing tunnel placements and graft fixation with screws after ACL reconstruction

Rehabilitation after ACL reconstruction is under supervision of trained specialist physiotherapists, in close liason with the surgeon, and is progressive for 6-9months, with an aim to return to sports at about 1 year. (Click on [Knee/ACL Rehab & exercise] link at top for further information on rehabilitation and exercises) 

Complications of ACL Reconstruction
  • Infection: (0.5-1.0%) May require antibiotics if superficial, or if deep may involve further surgery and monitoring with blood tests with delay to rehabilitation and possible compromise of the graft resulting.
  • Stiffness: Post operative physiotherapy and strict adherance and participation in the exercises is important in preventing loss of movement. Contractures and loss of movement may result if there is poor compliance.
  • Pain: Donor sites for the graft may cause pain (Thigh in the case of hamstrings and knee cap and front of knee if patella tendon). A subtle loss of knee extension can result in aching at the front of the knee. Most surgical pain has settled after the first few days and in general patients report the procedure was "less painful than they originally thought". Restriction in the ability to kneel for prolonged periods is occasionally reported. Dependant on other injuries such as cartilage tears or damaged joint surface, there may be residual pain in the knee joint.
  • Deep Vein Thrombosis (DVT): This is very rare after this particular procedure but can occur. Maintaining mobility and hydration keeps the blood thin and flowing and greatly reduces the risk. Routine use of blood thinning agents are not felt to be necessary after this procedure.
  • Fracture: Very rare (0.2%).The kneecap and tendon are weakened by taking a core of bone out of it when harvesting the patella tendon graft. It generally regains its strength over the first 6 weeks. An uncontrolled fall or slip in the first few weeks can predispose it to fracture which may require further surgery and compromise the overall result. Crutches are provided and should be used for the first 2 weeks, and general care in avoiding falling should be taken to avoid this complication.
  • Graft failure: (<5%).Sometimes the graft is resorbed for unknown reasons. Failure of the graft to revascularise renders it permanantly weak and thin, and affects people who smoke or are diabetic or on steroids more commonly. You are advised to refrain from smoking post operatively to reduce the risk of graft failure. Further injury before the graft is strong enough can risk it re rupturing. Full return to contact sports should be deferred until appropriate assessments and clearance have been obtained from the physiotherapist or Mr Siddiqui. Just as an injury with significant force can result in rupture of the natural ACL, any injury of sufficient magnitude can rupture the graft in future sporting activities. Technical errors and tunnel malpositioning, usually by inexperienced and low volume surgeons is another cause for premature graft failure.
  • Swelling: The knee may tend to swell in reaction to activities and usually this is an indicator of doing more than the knee joint can handle and tends to improve with the passage of time. If there is substantial joint damage then there may be some degree of residual swelling which persists.

Other Ligament injuries include Medial Collateral (MCL), Posterior Cruciate (PCL) and the Posterolateral Corner (PLC). These latter 2 can be very high energy injuries and occasionally can be part of a dislocated knee which can be limb threatening.

Below is a post operative X-Ray of a PCL Reconstruction

Although less common, and not always requiring surgery, it is important to treat these injuries correctly from the time of injury to reduce the risk of long term malfunctioning of the knee. Reconstruction of these ligaments for chronic injuries requires a careful assessment of the abnormal movement pattern in the knee and can be carried out if proper indications exist. As a general guide for these ligaments, if acutely injured and not requiring early surgery, rehabilitation can usually be achieved over a 6 week period with:

1. Appropriate rest and icing for swelling control.
2. A tubigrip gives reasonable support and can also aid with limiting swelling.
3. Crutch assisted ambulation with weight bearing as pain allows.
4. Using a hinged knee brace with an aim to regaining full range of movement as soon as possible.