By Don Williams
B.Sc., M.Chiro., ICSSD., PG Dip. NMS Rehabilitation,
Cert. DNS. Memb: CAA, FICS, CEA.
This month I thought I would write a brief article about the knee.
The Knee is such a fascinating joint and unfortunately, is a regularly injured joint, necessitating visits to our clinic for many people. We regularly receive referrals to assess knee injuries to identify what is actually wrong and how to manage the problem. This often necessitates us referring out for MRI scans and in some cases on referral to some of the excellent orthopaedic surgeons that we deal with.
Types of Knee Injuries:
Knee injuries and pain associated with those injuries generally fall into 3 categories.
Firstly, degenerative problems:
This can be osteoarthritic change or general wear and tear due to age or overuse of the knee.
Often age correlated or a result of lots of aggressive sport in the younger years.
Secondarily, biomechanical overload injuries:
These are often the result of; genetic mechanical issues such as pronation of the feet and ankles, “Knock knee”, “bow legged” posture of the knees, inappropriate footwear, poor technique in running, walking and other fitness activities, poor setup on bike position or sporting equipment or weaknesses and imbalances of the supporting musculature.
Thirdly, the pathological or traumatic injuries:
These are things like anterior cruciate ruptures (ACL), Meniscal tears (often referred to as the cartilage), fractures, and collateral ligament tears and issues. Bursitis and tendonitis issues are sometimes grouped into this category but are often more accurately grouped into the second category.
But what makes the knee so susceptible to injury:
Several factors really. The knee can be thought of as a force transducer. When we are walking, running, turning and jumping, our knee is subjected to high forces or loads in a multitude of directions.
The mechanics of the knee are complex and this article will be far from exhaustive in the description of the knee. But in basic terms the knee is a rolling/gliding hinge joint. Thinking simply, the knee is not a simple hinge (like a door), as the knee straightens, the femur glides across the tibia as it rolls towards the straightened position. This is why the end of the femur has a lengthened cam-like shape, in contrast to the relatively flat shape of the top of tibia. This means that the contact point and force vectors through the joint constantly change as the knee bends and straightens, combine this with the fact that the knee also pivots slightly right at the end of the straightening process make the knee a regularly injured joint.
Many health practitioners are taught at university that for the knee to have a pathological or major injury, there must be a large impact or nasty injury mechanism occurs to cause the damage. However, this is very clearly not the case with many of the patients we see at Institute of Sports and Spines.
In fact, the 2 worst knee injuries I have seen this year came from very low force activities; one from standing up after sitting on the ground and one from walking along the ground at work and turning to speak to someone. In fact, my own knee injury was not the result of a twist, fall or accident, but purely jogging along a flat footpath, the articular cartilage got caught and tore and it has been a problem ever since.
Scans and Imaging for the knee:
Depending on the injury or suspected injury, a range of scanning options are used.
Xrays and pretty good for looking at fractures of and around the knee, gross degenerative change and biomechanical position, they are not good at assessing soft tissue and ligament issues.
Ultrasounds are used to look at tendonitis and bursitis issues and muscle tears around the knee.
MRI scans are generally the image of choice for the knee and are the only means to effectively view meniscal tears, cruciate ligament injuries, collateral ligament injuries and articular cartilage defects.
I have included a couple of images below for interest.
Image 1 Image 2
Image 1 above, the green oval shows reasonable articular cartilage with some thinning. The red circle shows a tear or defect in the cartilage (the white area), the end of the bone has a light area which is bone swelling.
Image 2 The blue circle shows good articular cartilage and a healthy meniscus in the correct position (black triangle on the right side).
The red circle shows the lateral meniscus in the wrong place (this is bad ;)) and the green arrow shows us where it should be.
Image 3 to the left shows a vertical tear in the meniscus and a little bit of swelling to the left of the arrow.
Management of Knee Pain:
When you have knee pain, correct assessment and diagnosis of the problem is critical. We have unfortunately seen many patients who have had a lot of treatment for the wrong diagnosis, resulting in poor outcomes. A comprehensive physical and orthopaedic examination should give a working diagnosis which may then indicate treatment direction or relevant investigations to confirm the suspected diagnosis.
At IOSAS, we generally start our assessment with gait analysis, looking at joggers, work shoes etc, analysis of movement patterns and muscle strength to look for weakness and imbalances, followed by an orthopaedic joint assessment. This then directs how we will manage the presentation to move you towards the outcome you desire.
Most biomechanical issues of the knee and overload syndromes can be managed conservatively and don’t progress to surgery. Advanced degenerative change of the knee will often require joint replacements and ruptures of ligaments and meniscal tears which catch or lock will usually require surgery with a degree of urgency.
For many overload / degenerative and biomechanical issues, addressing mechanical issues and contributing factors can be a big part of the solution. Acupuncture, Massage and Chiropractic and other physical therapy interventions can be useful to address the current pain presentation. Progression towards rehabilitation and retraining may be indicated to prevent recurrence.
Due to the nature of the cases that we see, some patients require surgical intervention to help resolve their issues. It is vital in the post-operative phase to focus on rehabilitation and strengthening to make sure there is relatively good balance or symmetry in the strength and control of the knees to hopefully prevent future recurrences.
Generally, effective assessment and management of knees gives a greater probability of a good outcome.
If you have a new or ongoing issue with your knee, come in and see us, we might be able to help you get a better outcome.