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Common Knee Conditions

Dr Samuel MacDessi's picture
Submitted by Dr Samuel MacDessi on February 18, 2012

Anterior Knee Pain

“Anterior knee pain” refers to pain coming from the front part of your knee. Other names for this condition include “patellofemoral pain syndrome”, “patellofemoral overload”, and “patellar chondromalacia”. It is one of the most common conditions affecting the knee joint.

We are lucky enough to have a highly regarded and respected Orthopaedic Surgeon, Dr Samuel MacDessi from Sydney Knee Specialists to enlighten us on the topic of anterior knee pain. If you wish to contact SKS their details can be found on our alfresco friends page.

Where does Anterior Knee Pain arise from?

Anterior knee pain arises when too much stress is applied to the patella (kneecap) where it contacts the groove of the femur (thigh bone). The pain also can be produced from the surrounding soft tissues including the knee joint capsule, tendons and ligaments.

Knee Anatomy

The patellofemoral joint is one of three compartments of the knee joint. As the knee straightens and bends, the patella moves in a groove on the femur called the trochlear groove. The patella is designed to glide into this groove as the cartilage covering the reciprocal surfaces of the femur and patella come into contact. The bones are formed so that the patella stays in the groove of the trochlea without moving out of place.

The quadriceps muscle at the front of the knee, especially the inner portion called the vastus medialis obliquis (VMO) help guide the patella into the trochlear groove as the knee bends. This muscle plays a critical role in helping the patella stay in its position and not slip out of place. The VMO also helps reduce shearing forces when the patella moves against the trochlea. There are also other supportive ligaments surrounding the patella which help it glide correctly within the trochlear groove.

Knee Anatomy


Risk Factors

Anterior knee pain is extremely common throughout all age groups. It is especially seen in active healthy young athletes and teenage girls. This may arise from a weakness in the quadriceps muscle at the front of the thigh and its inner part (the VMO) that helps support the patella. Additionally poor flexibility, problems with anatomical alignment of the bones and inappropriate sports training techniques may exacerbate this problem. Occasionally a direct injury to the front of the patella may injure the cartilage of the patellofemoral joint and cause pain.

What symptoms commonly occur from “anterior knee pain”?

Anterior knee pain symptoms commonly occur as the knee is bent whilst bearing weight. Common examples include walking up and down hills, ascending and descending stairs, and standing up after a period of prolonged sitting. The pain may come on insidiously, however, repeated bending activities such as jumping or squatting may have precipitated the pain. Sometimes there is a history of recurrent pain in this area.

Assessment

When you see one of the surgeons at Sydney Knee Specialists, you will have a history and examination performed in order to confirm the diagnosis of anterior knee pain and exclude other associated problems. During the examination the surgeon will assess the alignment of your leg including the way that the patella glides in the trochlear groove as the knee bends. Weakness of the quadriceps muscle (VMO) will be assessed as well as any abnormal movements of the patella. Tenderness underneath the patella will be elicited as well as stability of the ligaments surrounding the knee joint. Flexibility of the hamstring and calf muscles will be examined as well as alignment of the feet as occasionally flat feet can exacerbate this problem.

Treatment

The main method of treating anterior knee pain involves initially rest, physiotherapy and occasionally anti-inflammatory medications. Avoiding activities (such as squatting, jumping and stair climbing) where the knee is flexed into deep flexion can help settle your pain more quickly.

As your pain improves, you will need to rehabilitate your knee to regain its motion, improve the strength of the muscles at the front of the knee and also improve your flexibility. This will not only speed up your recovery but will reduce the chances of your pain returning in the future. The main focus of treatment is improving the muscle strength of the inner portion of the quadriceps muscle - the vastus medialis obliquis (VMO). This muscle is extremely important in helping maintain the patella in the trochlear groove of the femur bone. As your strength increases, this muscle helps alleviate some of the forces that the patella experiences as it moves into the trochlear groove.

It is important that this muscle is strengthened in a non-painful manner. Your therapist will focus on improving your hamstring flexibility (muscles at the back of your thigh) as tight hamstrings can place significant forces on the patella. There is a tendon on the outer aspect of the thigh called the iliotibial band (ITB) which may also be tight, producing pain. Improving flexibility of this tendon can also be addressed with therapist. Other issues that may be corrected may be weakness of the hip rotator muscles (core muscle strengthening), and assessing the alignment of the foot, which can place abnormal forces on the patella itself.

Anti-inflammatories (NSAIDs) like Nurofen are often used during painful periods to settle the early phases of the inflammation process. Starting on an anti-inflammatory can help make it easier for you to start your rehabilitation. These should only be taken for short courses as recommended by your doctor.

If you are prone to this condition, taping the patella is often used to help the patella glide with less pressure. Your physiotherapist may trial this to see if it helps in relieving your anterior knee pain. Occasionally patellar braces may be useful in supporting the knee. Orthotics are often useful for people with flat feet as arch supports may improve the overall biomechanics of the lower limb. Over the counter arch supports are often a reasonable and relatively inexpensive option to trial.

Surgery for anterior knee pain is considered a last resort after all other treatments have failed. If there is fraying (chondromalacia) or a loose flap of cartilage behind the patella or on the trochlear groove, a knee arthroscopy may help smooth out the affected area. Sometimes the ligaments on the outer aspect of the patella are tight, causing it to tilt producing excessive pressure on the outer aspect of the patellofemoral joint. Releasing the tissues (a lateral release) may help reduce the tilting of the patella and the pressure on this side, improving your pain. Very rarely a small part of the tibia bone (tibial tubercle) needs to be shifted so as to realign the way that the patella glides on the femur. This is called a tibial tubercle osteotomy. This is a larger operation and is used as a last resort in patients with severe pain not relieved by other modalities.

Dr Samuel MacDessi - Orthopaedic Surgeon


Sydney Knee Specialists

Sydney Knee Specialists (SKS) is an orthopaedic practice dedicated to providing patients and the medical community with an unrivaled standard of care in treating knee disorders. SKS provide care for all people with knee problems, from young patients who may require reconstructive knee surgery, to older patients who may be suitable for joint replacement procedures.

The surgeons at SKS focus their surgical practice exclusively on the management of disorders of the knee. This allows them to provide highly specialised, expert and up-to-date services to both patients and referring practitioners.

Orthopaedic Surgeons

The surgeons at SKS are Australian trained orthopaedic surgeons, Fellows of the Royal Australasian College of Surgeons and Associate Members of the Australian Orthopaedic Association. Each surgeon has international sub-specialty experience in the management of knee disorders from prestigious centres including the Mayo Clinic, Harvard Medical School, The Hospital for Special Surgery, Mt Sinai Hospital and leading Institutions in the United Kingdom and Europe.

SKS surgeons have involvement in clinical research into the latest advances in knee surgery. They have had numerous works published in peer review journals, and have delivered lectures and scientific presentations at both national and international clinical conferences. All surgeons are dedicated to maintaining their own ongoing education and skills training to ensure they have a command of the latest advances in knee surgery.

The founding surgeons of SKS are Drs Darren Chen, Samuel MacDessi and Bradley Seeto. Their areas of expertise include total knee replacement (minimally invasive and computer-assisted surgery), unicompartmental knee replacement, revision knee replacement, arthroscopic knee surgery (ACL reconstruction and meniscal surgery) and cartilage transplantation of the knee (biological arthroplasty).