Published in the Massage & Myotherapy Journal, Volume 19, Issue 3, Spring 2021
Author, Rob Orr
Introduction
When a client presents with acute or chronic knee pain the first thing we need to consider is it the actual knee that’s driving the pain or is it coming from somewhere else. Also was it trauma or non-trauma related? If the knee pain coincided with a traumatic episode then more likely its coming from the knee, if its chronic is it altered biomechanics driving the pain? Is it a local knee obstruction that’s driving the pain (McKenzie & May 2003, Rosedale 2014)? Or is there nothing wrong with the knee and the pain is being created from a proximal region like the hip (Dr Bruce Mitchell), lumbar spine (Rosedale et al 2020) or SIJ (Dr Mark Laslett 2008). Is it a red flag masquerading as knee pain?
Why should you examine the lumbar spine, well there are two reasons why. First of all in 1991 Dr Kuslich and his colleague’s published a paper on the tissue origin of low back pain involving 193 patients. 17 different tissue types of the lower back was stimulated for a painful response through blunt force and electrical stimulation, the most common tissue type that caused pain was the disc (66-72%).
Secondly Richard Rosedale and his colleague’s published a paper in 2020 called EXPOSS (extremity pain of spinal source), this study comprised of 322 patients with isolated joint pain of the upper and lower body. Out of the 322 patients 181 of them there symptoms were spinal based and 81% had no spinal symptoms. So the moral of the story is clear the spine!
Summarising the above is it the knee? Lumbar spine? SIJ? Could it be a combination? Or is it a serious spinal pathology presenting as a mechanical source of pain (serious spinal pathology’s are out of the scope of this article as this article will focus on mechanical pain. But Ill quickly mention that serious spinal pathology presents >1.8% of the population (McKenzie & May 2004), even though this is a low statistic its always essential that you clear Red Flags by taking a thorough history. Is it a serious pathology involving a local tumour like a Osteosarcoma or a Ewing’s sarcoma in the distal femur or mid femur region? I think its important prior to continuing this article that we address the signs and symptoms and the most common age group that could present with an Osteosarcoma or a Ewing’s sarcoma presenting as knee pain. An Osteosarcoma is a bone cancer that most often presents in the long bones like the femur but can occur in any bone, it tends to occur in children and young adults and the symptoms are localised bone pain and inflammation. If this red flag is identified early and hasn’t spread the survival rate is high, so if your client in this age group presents with distal thigh pain with no history of trauma, no change or minimal change in range of motion, no position that eases the pain this needs to be ruled out via a plain film x-ray. Ewing’s sarcoma is an aggressive cancer that may spread to the lungs, other bones and bone marrow potentially causing life threatening complications, common age groups affected are children and young adults. So once again if the client presents with no history of trauma, no change or minimal change in range of motion, no position that eases the pain this needs to be ruled out via a plain film x-ray. The rest of this article will now focus on establishing whether the clients acute or chronic pain +/- loss of motion is mechanical in nature, and whether it’s being produced by local structures of the knee, or proximal regions as in the lumbar spine or the SIJ.
Subjective Examination
Prior to the physical examination on questioning you should get clues from the client if there are any positions if that makes them better or worse. For example, better standing and walking (extension), worse sitting and bending forward (flexion). Or is the client worse standing and walking, and better sitting. Even though this is only the start of the investigation these clues are important because your client is telling you what position makes them better or worse and its more likely mechanical pain! During the subjective examination I recommend that you change their posture while in a seated position by using a lumbar supporter or a towel rolled up into a sausage shape with a rubber band at each end to maintain the shape to promote a lordotic curve in their lumbar spine regardless of where the pain is presenting. This is a very important part of the examination as it will help you ascertain whether the spine is playing a role in the clients complaint regardless of where the symptoms are. I do this with every client and I’m still blown away with the results this achieves regarding establishing where the pain is coming from. Usually you will know if the spine is involved within 3 minutes or sooner as the clients symptoms will either improve or at times completely abolish, if the symptoms get worse this also informs you that the spine is involved.
Physical Examination
The first part of the physical examination will consist of a static postural check looking for signs of altered biomechanics then functional testing looking for altered movement patterns that could be contributing to the clients symptoms, this could be in the form of sit to stand, squats, lunges, single leg squat or other specific movements. From here it’s now time to isolate the knee and test active, passive and resisted (if applicable) range of motion in a supine position or whatever position you prefer. Is there pain during motion? End range pain only? Or is the motion obstructed and the client can’t get to end range +/- pain. The order of functional testing versus isolated testing doesn’t really matter unless the clients symptoms are highly irritable and if this is the case start with isolated testing and progress from there, orthopaedic testing would follow if applicable. Now you can’t examine everything in the first session as you need to treat as well but it is important that the knee, hip and lower back are all tested for a comprehensive examination. Also its important to note that If the pain is constant its more likely that the pain is chemically driven and If the pain is intermittent its more likely that the pain is being driven by mechanical sensitivity of that specific tissue/s, or coming from somewhere else like the lumbar spine.
Differential Diagnosis
The D/D’s will be based on all the information you have gathered so far from the medical history, subjective and objective examination. The most common D/D’s I come across are; (1) local knee obstruction (McKenzie & May 2003, Richard Rosedale 2014) (2) Discogenic +/- lower back pain (McKenzie & May 2003, Richard Rosedale et al 2020) (3) Patella Femoral Pain (Farina 2021) (4) Patella Tendinopathy (Rio 2017, 2019). In the past four to six months I have treated a lot of knee complaints with successful outcomes where the majority of the them were knee obstructions or lumbar spine related.
Discussion
The history of the client combined with the above physical examination should help you clinically assess: (1) Red and Yellow Flags. (2) Which structures are more likely involved. (3) Which structures are less likely involved. (4) Is there an injury leading to chemical sensitivity in the form of inflammation. (5) Is it more mechanical pain due to the tissue being structurally compromised. (6) Is there evidence of a joint obstruction. (7) Is it non mechanical in origin. If the clients history indicates that a sustained position or a repeated movement of the knee in a specific direction rapidly reduces their pain and significantly improves their range of motion this is more likely a local joint obstruction. If the client presents with knee pain in the clinic and you change their posture to more of a lordotic posture while seated and their knee pain subsides, abolishes or gets worse this is strong supportive evidence that the lumbar spine is involved, and the most common structure to cause this is the disc. If the client points directly to the tendon with a supporting history of the pain never changing locations and worse first thing in the morning this supports a patella tendon pathology.
Summary
If your client displays a rapid improvement in their knee with a sustained position or a repeated movement in a specific direction it is more likely that something is obstructing the knee joint leading to the pain. If the client displays a rapid improvement in their knee symptoms by performing repeated movements of the lumbar spine in a specific direction its more likely that the disc is involved. Always be aware that the hip and sinister pathologies can also cause knee pain.
Bibliography
1. McKenzie R, May S 2004, The Lumbar Spine Mechanical Diagnosis & Therapy volume one, Spinal publications Waikanae, New Zealand.
2. McKenzie R, May S 2004, The Lumbar Spine Mechanical Diagnosis & Therapy volume two, Spinal publications Waikanae, New Zealand.
3. Laslett M 2008, Evidence-Based Diagnosis and Treatment of the Painful Sacroiliac Joint, Journal Manual Man Therapy 16:3:142-152.
4. Kuslich et al 1991, The Tissue Origin of Low Back Pain and Sciatica: A report of Pain Response to Tissue Stimulation During Operations on the Lumbar Spine Using Local Anesthesia, Department of Orthopaedic Surgery, University of Minnesoda, America, Vol 22. No 2 April 1991.
5. Rosedale et al 2020, A Study Exploring the Prevalence of Extremity Pain of Spinal Source, J Man Manip Ther.
6. Farina et al 2021, Meniscal and Mechanical Symptoms Are Associated with Cartilage Damage, Not Meniscal Pathology, Journal of Bone Joint Surgery.