OSTEOARTHRITIS OF THE HIP AND KNEE – PART 1
Updated: Nov 19, 2020
Hip and knee osteoarthritis (OA) are two of the most common musculoskeletal conditions we see in our clinical practice. Considering its high prevalence in our society, it is not surprising that OA is the leading cause of disability in our aging population. Up to 40% of the population suffer from OA between the ages of 45-55, and by the time we reach the age of 75, over 80% of the population has OA. (1) On a personal level, OA of the hip is something that I have a lot experience with, over 3 years ago I had my right hip replaced.Not a fun experience going through all that pain, but it did teach me a lot about what it takes to address this condition and get back to a fully functional life again.
Although OA is not a condition that reduces life span, it does have a significant effect on the quality of an individual’s life. Fortunately, manual therapy and exercise can make a significant difference on this condition by slowing its progression, reducing or eliminating pain, and improving overall function (3, 17, 21, 22). In some cases, such as myself, surgery is necessary to regain full function, but that is not always the case.
WHAT IS OSTEOARTHRITIS?
OA is a degenerative disorder resulting from the breakdown of cartilage (articular cartilage) in synovial joints. In addition to breaking down cartilage, OA also affects the underlying bone (subchondral bone) and the connective tissue that lines the inside of the joint capsule (synovium).
Basically, damage caused by OA occurs at a faster rate than the body is able to repair itself, resulting in ongoing degeneration. At a cellular level, several pathomechanical stresses occur (proteoglycan loss and death of chondrocytes.) (3)"Patho" means related to disease, and “mechanical” in this context refers to damage relating to a process that involves purely physical factors.
RISK FACTORS FOR OSTEOARTHRITIS
The causes of OA can be multi-factorial, covering everything from genetic causes to trauma induced injuries. The following are some of the common risk factors for osteoarthritis:
Age – With the normal aging process there is a decrease in overall cartilage volume in joints, decreased proteoglycans, and decreased vascularization (blood flow). All of which can lead to cartilage degeneration and OA.
Diabetes – There is increased evidence that diabetics have alterations in fat (lipid) metabolism, and that hyperglycemia (excessive levels of glucose in the bloodstream) could have a direct influence on cartilage health and subchondral bone. Damage to these structures could contribute to the development or progression of OA. (11, 24)
Genetics - Family history of arthritis.
Muscle Weakness - This is a very important factor since inactivity can accelerate the process of osteoarthritis. OA is a problem with joint degeneration, but the state of the surrounding soft tissue is just as important. For example, strength has been shown to directly impact the progression of OA of the knee. (10).
Obesity - The relationship between OA and obesity is very clear. Increased weight increases the mechanical stress on weight-bearing joints. Obesity also increases inflammatory risk for OA since the cytokines in adipose tissue promotes low grade inflammation. (8). Weight loss can have a substantial positive effect on decreasing stress and OA for both the hip and knee joints. (13)
Previous case of Inflammatory arthritis (IA)– IA is joint inflammation caused by an overactive immune system.
Previous surgical procedures, which can create compensations leading to increased stress, friction, and break down of cartilage.
Repetitive motion – causes increased mechanical stress on the joints, and further inflames the occurrence of OA (9)
Trauma - Previous trauma substantially increases the risk factor for OA, by as much as 20 times. (12, 24)
A FEW MYTHS ABOUT OSTEOARTHRITIS
There are some myths than need to be considered when discussing the topic of OA:
Worsening of OA is inevitable – This just NOT true. Having mild to moderate OA does not mean it will always progress into severe debilitating OA. (2)
There is nothing I can do for my OA – Again, this is NOT true. It is true that there is no cure for OA. That being said, manual therapy and exercise can decrease pain, increase function, and decrease the overall risk factors associated with the progression of OA. (3)
The best way to treat OA is to just leave it alone and rest – Actually NO this is not true, not managing or poorly managing OA can lead to chronic pain, disability, and a cascade of cellular events that could have been prevented. (4)
Avoid sports at all costs, it will definitely lead to OA – The good news is that participating in sports, exercising, and physical activity in general is not associated with the progression of OA. In fact, research is demonstrating it can be protective in nature. (5,6). Even continuing to run is not bad for you, unless you already have severe OA before you begin running.
HALLMARKS OF KNEE & HIP OA
The hallmarks of hip and knee osteoarthritis are limited range-of-motion (ROM), crepitus during active motion, increased sensitivity during palpation, deformity, and swelling of the bone. The American College of Rheumatology (ACR) use the following criteria: (15,16)
Pain for longer than one month.
Stiffness in the morning for less than 30 minutes.
Joint tenderness on palpation.
Pain for longer than one month.
Hip flexion that is less than 115 degrees, and internal hip rotation that is less than 15 degrees.
Stiffness in the morning for less than 60 minutes.
Patient is usually 50 years and older.
PROGRESSION OF OSTEOARTHRITIS
The symptomatic progression of OA can be divided into three symptomatic stages.
Stage One – Early OA
Occasional episodes of sharp joint pain with certain activities.
Over all function is not limited, except on high impact activities.
Stage Two – Mild OA
Increased frequency and duration of joint pain.
Some patients complain about the joint giving away or locking.
Pain is now affecting activities of daily living. Pain is especially noticeable after getting out of bed and after sitting for long periods of time.
Stage Three - Severe or Advanced OA
The pain is often constant.
Pain can vary in intensity from an aching dull pain to severe pain.
This stage of severe or advanced OA is characterized by a high level of functional limitations.
It should be noted that there is a high degree of inconsistency in correlating radiographic evidence against pain intensity, symptoms and functional limitations. The results also vary greatly between individual cases. Some patients show significant radiographic evidence of OA but NO symptoms, others patient will have no radiographic evidence but significant symptoms. (14)
EXAMINATION AND DIAGNOSIS OF HIP & KNEE OSTEOARTHRITIS
A comprehensive orthopedic and neurological assessment (plus indicated imaging) should be performed on every patient with hip or knee OA to asses the degree of degeneration that has already occurred.
Note: This section is technical and is written for practitioners, feel free to skip this second and go directly to Part 2.
Standard x-rays (anterior, posterior, and lateral views) are very cost effective and provide valuable information in the diagnosis of OA.
Magnetic Resonance Imaging (MRI) do provide effective soft-tissue and osseous information that cannot be achieved through standard X-rays. However, MRIs are very expensive, and not available to everyone.
Ultrasound has the advantage of not involving radiation but is usually used for the assessment of muscles and tendon pathology. Ultrasound is not used for joint assessment.
Orthopedic & Neurological Testing
The first step in doing an assessment for OA is to rule out red flags (non-musculoskeletal causes of pain). This is often achieved by taking a comprehensive history, followed by an appropriate orthopedic and neurological examination. The following are some of the common tests we would perform an evaluation of both the hip and knee.
Hip Examinations should include:
Straight Leg Raise Test to rule out discogenic radiculopathy (sensitivity 91-92). (25)
Fulcrum test to check for fracture/stress fracture of hip (sensitivity 88-93). (26, 27)
Thigh Thrust Test to evaluate pelvic girdle related pain (sensitivity 88). (28)
FADDIR Test to evaluate flexion, adduction, and internal rotation (sensitivity 99). (29)
Knee Examinations should include:
Straight Leg Raise Test to rule out discogenic radiculopathy (sensitivity 91-92) (25)
Posterior Drawer (PCL, sensitivity 90%) (31)
Joint Line Tenderness which is a reliable clinical indicator of meniscal pathology. (34)
In addition to these orthopedic procedures, attention should be directed towards the assessment of the strength and length of certain muscles. These muscles should be assessed both bilaterally and unilaterally for imbalances. The primary structures that need to be assessed include:
Hip extensors, flexors, abductors, adductors – These muscles have a huge influence on both hip and knee function.
Quadriceps and hamstrings – The quadriceps are involved in stability and control of the knee.
Ankle dorsi and plantar flexors – These muscles are extremely important in shock absorption, stability, and control of the knee.
It is extremely important to perform a thorough neurological examination. This examination should include:
Dermatomal Patterns – Dermatome maps are clinically useful in determining a change in sensation. That being said, dermatomal charts may NOT show you an exact level of nerve root lesion. We must take into consideration that there is great deal of individual variability and overlap between dermatomes. Even the dermatome charts do not have consensus.
Deep Tendon Reflexes - Typically, decreased tendon reflexes indicate that there is a problem with the peripheral nervous system, while increased reflexes indicate a problem with the central nervous system.
Medial hamstring (L5-S1).
Lateral hamstring (S1-S2).
Posterior tibial (L4-L5).
Reflex Grading (18):
0 - Absent
1 - Reduced
2 - Normal
3 - Exaggerated
4 - Clonus
Myotomes - A group of muscles innervated by the motor fibres of a single nerve root is known as a myotome.
Plain radio-graphs are usually necessary for patients 50 years and older. Also patients who are experiencing pain at rest, have a history of serious trauma, or other conditions such as: cancer, fractures, metabolic bone disease, infections, or inflammatory arthropathies.
Knee extension (L3).
Ankle dorsiflexion (L4).
Great toe extension (L5).
Ankle plantar flexion, ankle eversion, hip extension (S1).
Knee flexion (S2).
Motor Grading (18):
0 - No visible or palpable contraction. (None)
1 - Visible or palpable contraction, no movement. (Trace)
2 - Full range of motion with gravity eliminated. (Poor)
3 - Full range of motion against gravity. (Fair)
4 - Full range of motion against gravity and moderate resistance. (Good)
5 - Full range of motion against gravity, full resistance. (Normal)
DIFFERENTIAL DIAGNOSIS - CONSIDER THE POSSIBILITIES
It is important to remember that a diagnosis of Osteoarthritis is always a “working diagnosis”. No diagnosis is completely definitive, it’s always the practitioner’s best guess based on history, examination findings, imaging, and other diagnostic criterion. With osteoarthritis, keep in mind some other possible differentials, such as:
Lumbar Radiculopathy – Referred pain from the lumbar spine.
Avascular Necrosis – This refers to death of bone tissue due to a lack of blood supply. Possible causes include excessive alcohol use, blood clotting disorders and chronic steroid usage. A standard X-ray would be useful to help to rule out these other conditions.
Gout – with cases of gout, the joint and surrounding areas are usually hot to touch and extremely painful on palpation.
Rheumatoid arthritis (inflammatory arthritis) – In these cases, the joint is also usually hot. A lab test can be used to rule out the Rheumatoid arthritis factor. High levels of rheumatoid factor in the blood are most often associated with autoimmune diseases.
In cases of knee pain, it is important to consider referred pain caused by hip osteoarthritis, bursitis, ITBS, ligamentous injury, and osteochondritis in younger patients.
In part two of “Osteoarthritis of the Hip and Knee” we will discuss using manual therapy techniques with video demonstrations showing both joint mobilization and soft tissue techniques that we use. Then we present video demonstrations showing common exercises that we prescribe to our patients with hip and knee OA.
Note: References are at the end of Part 2
DR. BRIAN ABELSON DC.
Dr. Abelson believes in running an Evidence Based Practice (EBP). EBP's strive to adhere to the best research evidence available, while combining their clinical expertise with the specific values of each patient.
Dr. Abelson is the developer of Motion Specific Release (MSR) Treatment Systems. His clinical practice in is located in Calgary, Alberta (Kinetic Health). He has recently authored his 10th publication which will be available later this year.
Make an appointment with our incredible team at Kinetic Health in NW Calgary. Just scan the QR code with your phones camera and click the link, or call Kinetic Health at 403-241-3772 to make an appointment today!