Osteoarthritis (Degenerative Joint Disease)
Osteoarthritis is also known as degenerative joint disease (DJD) and is what happens when the cartilage inside our knee joint begins to wear away, what is often known as ‘wear and tear’ of the joints. While degeneration is a normal part of aging, it can also eventually lead to knee pain, stiffness, and difficulty moving in a certain percentage of the population.
Those that are more susceptible to developing knee osteoarthritis are those who:
- Have injured their knees before (i.e. torn ligaments, previous fractures)
- Have a history of excessive loading to the knees (i.e. long-distance competitive sports like ultramarathoning)
- Have a congenital or developmental abnormalities (i.e. congenital subluxation, Legg-Calvé-Perthes disease, and slipped capital femoral epiphysis) which can contribute to OA development later in life
The main symptoms of knee osteoarthritis are:
- Morning stiffness (feeling like you need some time to ‘warm up’ your joints after getting out of bed!)
- Aching around the knee when getting up to stand after sitting for a long time
- Difficulty performing activities like squatting, balancing, or even walking without pain and stiffness
While knee degeneration is fairly common, one should try to focus on preventing this from becoming a condition that hinders you from achieving the optimal quality of life for your age! Obesity and diet have been two factors that we can change which are shown to have some impact on symptomatic or painful OA – results from the Framingham Study found that women who had lost about 5kg had a 50% reduction in developing a painful knee (1), and subjects who were lowest in Vitamin D had a 3-fold increased risk for progressive knee OA (2).
Patellofemoral Pain Syndrome
Patellofemoral pain syndrome (PFPS) is an umbrella term for ‘anterior knee pain’, or pain located in the front of the knee. It can happen across all ages and genders, although primarily seen in the age group of adolescents to those younger than 60 years old. A physician, physiotherapist, or chiropractor may suspect someone of having PFPS if someone comes in complaining of these symptoms:
- Pain predominantly in the front of the knee, surrounding the kneecap (not the sides or back of the knee)
- Pain intensifies when a person is doing activities which exerts extra load on the knee (e.g. bending or squatting, single leg squats, landing after jumping, running, hiking up and down hilly areas, descending stairs)
- Pain also worsens after a period of sitting down for a long time
Causes of PFPS are wide and varied, but they can often be attributed to overuse – thinking someone who is not accustomed to walking much and then going on a hike or 5km jog, or someone who has been squatting heavier weights than usual – which triggers inflammation around the kneecap and surrounding structures. There may be swelling around the patella (your kneecap), muscle weakness or tightness of the quadriceps, and a general feeling of discomfort on bending and moving the knee.
They can usually be confirmed using several assessment techniques, such as:
- Patella grind test, which confirms that there is a sensitivity to the structures surrounding the front of the knee
- Patella mobility testing, which helps to identify the degree of swelling, pain, or limitation of movement around the kneecap
- Movement analysis, especially single leg standing, squatting, and walking – this helps to identify muscle imbalances which can lead to excessive and unnecessary loads to the knee.
Patella tendinitis (Jumper’s knee)
Jumper’s knee is also known as ‘patella tendinitis’ or ‘patella tendinopathy’, and is known by that name due to its prevalence among jumpers! Repetitive jumping (basketball, long jump, high jump sports) is an activity that places accumulated stress on the patella tendon, which is the ending part of the quadriceps muscle which reaches from the base of your kneecap goes down towards the shin, and attaches itself to a tubercle on your shin bone (tibial tuberosity).
This cumulative stress can result in tiny tears along the tendon which triggers inflammation, pain, and difficulty with performing high-stress activities on the affected knee. While jumping can definitely cause this, it can also be seen in people who run long distances or across hilly terrain! One of the biggest risk factors of this injury occurring is insufficient rest or recovery time between sessions or training seasons of high intensity sport.
Main symptoms of Jumper’s knee include:
- Complaints of localised pain and tenderness over the lower part of the kneecap
- Pain with prolonged sitting, squatting, and stair climbing – again, usually over that specific area
- There is usually no pain at rest, but sudden pain during loading which stops almost immediately after the load is removed
- Examination of the knee might show swelling that is not around the entire kneecap, but also localised to the tendon region, which is painful to pressure. Resisted knee straightening can reproduce a similar pain.
These three conditions (osteoarthritis, patellofemoral pain syndrome, and patella tendinopathy) are among the most common complaints that people have regarding the knee. Identifying your diagnosis is only the first step which can be done through our thorough initial consultation process, but the next step is understanding what treatment options are possible!
Our next article will help you to understand the different treatment approaches that can help to reduce pain, increase strength, and gain back your quality of life – stay tuned!
- Felson D.T. et al (1992) Weight loss reduces the risk for symptomatic knee osteoarthritis in women. The Framingham Study. Ann Intern Med. 1992;116(7):535–9.
- McAlindon T.E. et al (1996) Relation of dietary intake and serum levels of vitamin D to progression of osteoarthritis of the knee among participants in the Framingham Study. Ann Intern Med. 1996;125(5):353–9.