Prevalence of knee pain and its impact on mobility and quality of life
Knee pain is extremely common and affects people of all ages. In most of us, it is temporary and doesn’t really bother us very much. In others, knee pain may be more severe and affect many aspects of our daily lives. The cause of knee pain could be multifactorial. Knee pain could also happen with other symptoms such as swelling, clicking, stiffness or instability.
Younger patients may experience knee pain due to a sprain or sports-related injury. They are often involved in twisting movements which may cause a tear in their protective meniscus or stabilising ligaments. Other than pain, it is common for them to experience knee swelling and instability. They often seek help if their symptoms last more than 2 weeks despite appropriate rest and icing.
It is very common for older patients to experience slower walking speeds and walking upstairs one step at a time. They also describe severe knee pain and swelling at the end of the day and the inability to stand or walk for long periods of time. In more serious cases, the knee pain prevents them from leaving their homes and they may even feel socially isolated from friends.
Basic anatomy of around the knee
While we often speak about the anatomy of the knee in relation to its associated bones, ligaments, cartilage and menisci, we often forget that there is a large sleeve of muscles and tendons around the knee that work to move the knee during daily activities. Ligaments are structures which hold two or more bones together while tendons connect muscle to bone. The quadricep muscle is a large thigh muscle made up for 4 parts and is attached to the patella bone through the quadriceps tendon. The patella tendon sits below the patella, connecting it to the tibia bone.
At the back of the thigh and knee lies two sets of muscles that overlap each other. The set of hamstrings come from our buttock region and cross the back of the knee. The calf muscles or gastrocnemius muscles attach to our heel bone through the Achilles tendon. 
The anterior compartment of the knee consists of the patella, femoral trochlear, quads and patella tendons.
Common causes of knee pain
Patello-femoral pain describes pain arising from the anterior compartment of the knee knee. It often affects the patella or femoral trochlear cartilage, but it may also be the tendons attached to the patella which are inflamed. This is often referred to as runners’ knee or jumpers’ knee. You obviously do not need to be a runner or a jumper to experience this pain. Wearing out of patella cartilage may be the results of malalignments of the patella, trauma or degeneration.
Patients who experience severe twisting injuries of their knee during sports may have ruptured their anterior cruciate ligament (ACL). This may occur in isolation or with tears to their meniscus or other ligaments around the knee.
Older patients may experience long-term worsening knee pain related to generalised thinning of their cartilage. They may also have degenerative tears of their meniscus with malalignments of the knee. These are all phenomenon found in knee osteoarthritis.
Non-Surgical Treatments
- Initial remedies: most patients who experience knee pain would firstly rest their knee by reducing their physical activities. They may apply ice to their knee to reduce swelling or apply a compression around it to provide some stability to the knee.
- Medications: Simple analgesics such as anti-inflammatory medication (NSAIDs), paracetamol or an opioid (codeine, tramadol) may be used to reduce the initial knee pain. It is also important to take some of these medications so that you may continue to perform your daily tasks, including work and caring for your family.
- Knee injections are very effective in reducing pain and inflammation. Most of these injections are performed under local anaesthetic. They usually contain a steroid and local anaesthetic. Depending on the underlying cause of the knee pain, these injections may be effective for several months up to a year.
- Physical therapy, physiotherapy and rehabilitation are important aspects of recovery. It helps to improve swelling around the knee, improve the function and range of the knee as well as preparing athletes to return to the sport they love. Middle-aged patients require physical therapy to improve their muscle strength, stability while walking and reduce the risk of falls.
- Modification of activities usually takes place either consciously or subconsciously as patients make changes to their lives to accommodate their knee pain. They may reduce their walking speed and distance, change their footwear or even start using a walking aid to improve their balance. Many will change their sports so that they can continue to be active without worsening their knee pain.
As humans, we are all made quite different from person to person. Some of us have fairly straight legs, while others or either bow legged (varus knees) or have knocked knees (valgus knees). Patients with valgus knees experience more lateral or outward translation of their patella and this increases the risk of subluxation or dislocation. The greater their bowleggedness, the greater the force to sublux or dislocate the knee (shown in yellow arrows).
Indications for Knee Surgery
- Surgery is a last resort for most people. After seeking assistance from a medical professional, appropriate clinical examinations, imaging and assessments would have been done to determine the true cause of their knee pain.
- A trial of conservative treatment would have been taken to improve the knee pain without surgery. If patients continue to experience severe pain and disability despite conservative treatments, surgery should be considered.
- There should be extensive discussions between patients and their orthopaedic surgeon about what the surgery will achieve. All the pros and cons should be discussed and patients should be allowed to voice their concerns and expectations with regard to surgery and what happens after that. Rehabilitation is an important part of the treatment and all aspects of that should be discussed in detail. It is best to include family members or carers in these clinic discussions.
Types of Knee Surgery
- Arthroscopy or key hole surgery: these minimally invasive techniques are used to address injuries to the meniscus, cartilage and ligaments around the knee.
- Osteotomy or bone realignment procedures involves breaking a bone to correct its alignment, then fixing it in place with plates and screws. These is done as part of knee-preservation techniques in younger patients. An arthroscopic procedure may also be done with these osteotomies.
Arthroplasty describes knee replacement procedure where the cartilage and meniscus may be too far damaged to be salvaged. Total or partial knee replacements may be done through conventional, navigational or robotic techniques.
Patients with severe valgus knees may require a knee straightening procedure to correct their leg alignment. This may be done to prevent further patella dislocations from happening in future.
Recovery and Rehabilitation
- Post-operative care is extremely important to avoid complications and enable patients to recover well. They may receive antibiotics and analgesia for pain and to prevent infections. Icing around the joint is helpful to reduce swelling and inflammation.
- Physical therapy is usually started the day after surgery so that patients may start to ambulate safely with a walking frame or crutches. This is especially important for their confidence before they return home. Muscles also need to be worked before they start to weaken. Early ambulation and physiotherapy helps to address this.
- Long-term outcomes and prognosis depends on patients general physical health, the severity of their condition and what surgery they underwent. Most surgical wounds heal within two weeks but normal walking or return to active sports may take 2 to 3 months. Everyone is different and the physiotherapists are there to customise your rehabilitation plan.
Conclusion
- Please seek professional medical help if you are experiencing worrying knee pain. A thorough clinical examination and imaging are important to get to the bottom of things. Not all injuries require surgery as this is often the last resort.
- The medical consult is a change to discuss in detail with your surgeon what the options are dealing with knee pain. If surgery is need, the rehab and home plan must also be discussed for completeness.
