Understanding Arthritis and Osteoarthritis

Arthritis

• A chronic degenerative condition affecting the joints.
• The rate of degeneration varies depending on factors at the joint.
• Well-developed muscles can influence the rate of degeneration.
• Lack of pain does not indicate the absence of degeneration.
• Cartilage lacks nerve endings, so pain is not felt until the damage reaches the bone.

Osteoarthritis (OA)

• Caused by overuse of the joint.
• More common than rheumatoid arthritis.
• More related to physical activity.

Rheumatoid Arthritis (RA)

• An autoimmune disease causing inflammation around the joint.
• Less understood than OA, especially regarding exercise testing and prescriptions.

Osteoarthritis Types - Primary OA

• More common type.
• Cause is unknown.
• Factors include joint misalignment and cartilage inconsistency.
• Commonly related to aging and heredity.

Osteoarthritis Types - Secondary OA

• Can be linked to a specific disease or event.
• May occur in any joint as a result of injury, repetitive use, fracture, or metabolic issues.
• Can occur at any age.

Mechanical Stresses and OA

• Obesity leads to thick subchondral bone.
• Thicker bone cannot absorb force effectively, increasing wear on cartilage.
• Damaged cartilage leads to a slower rate of bone degeneration.
• Obese people experience more joint problems, especially in the knees and hips due to extra weight.
• Subchondral bone protects articular cartilage by absorbing transmitted stresses.
• Thick subchondral bone has poor absorbing capacity, leading to increased cartilage damage.
• Chondrocytes, which produce cartilage matrix, get damaged.

OA Pathophysiology - Joint Cartilage Changes

• Cartilage becomes softer and less able to withstand stress.
• Focal and progressive loss of hyaline cartilage occurs, causing it to thin.
• Cushioning function, which reduces mechanical forces, decreases.

Osteosclerosis

• Bone beneath cartilage grows thicker as a protective mechanism.
• Osteophytes develop as compensatory changes to compensate damage.
• Bone growth is not normal and loose bodies need to be removed.

OA Pathophysiology - Surrounding Tissue Changes

• Tissues surrounding the joint experience progressive inflammatory infiltrates.
• Thickening of the synovium occurs.
• Ligaments experience laxity.

Weakness of Bridging Muscles

• Weakness of bridging muscles contributes to pain and reduced movement.
• The brain reduces movement to protect the joint, decreasing neural drive to muscles.
• Initially, this protects but creates a long-term problem.
• Strengthening muscles around the joint is important for protection.
• Reduction in space between the joints results in increased friction.

Most Commonly Affected Sites in OA

• Spine
• Hands
• Knee
• Hip
• Foot
• Hip and knee are affected more frequently.

Incidence of OA

• Women have a higher incidence of OA in the knee and hip.
• Men have a higher incidence of OA in the hand.
• Wearing heels can shift weight and cause toe jamming.
• The most common reason for hip and knee replacement.
• Pain tends to increase sharply after age 50.

Signs and Symptoms of OA

• Localized tenderness
• Crepitation on motion (cracking of joint)
• Mild joint enlargement
• Synovitis (inflammation of synovial membrane)

OA - Deformities & Physical Activity

• Deformities occur in later stages.
• Radiologic changes, such as narrowing of joint spaces.
• Osteophytes and bone remodeling occur around the joints.
• Pain occurs on motion in early stages.
• Lack of exercise can accelerate joint deterioration.

OA - Pain & Stiffness

• Pain continues at rest in more advanced stages.
• Pain is aggravated by prolonged or intensive activity.
• Localized stiffness occurs, especially in the morning or after periods of inactivity (gelling).

Reduced Flexibility & Mechanical Lock

• In advanced cases, patients may have limited ROM, resulting in reduced flexibility.
• Mechanical lock can occur due to loose bodies.

Lack of Early Symptoms

• Lack of nerve endings in degenerating cartilage means symptoms may be absent in the early stages.

Risk Factors for OA

• Age
• Sex
• Reduced estrogen levels at menopause
• Bone density
• Obesity
• Repetitive jobs (kneeling and squatting)
• Joint injury
• Sports participation
• Muscle weakness
• Genetics

Sports and OA Development

• Normal articular cartilage may rupture if stress exceeds 25 MPa.
• Contact stress during running is 4 MPa, while jumping is 9 MPa.
• Joint pivots and jumps increase risk.
• Sports combining running, jumping, and torsional stresses increase the susceptibility of articular cartilage damage.

Progressive Overload for Connective Tissue

• Timeline for adaptation should be slower.

Cartilage & Running

• Running can increase cartilage density.

Patellofemoral Forces

• Best activities are those that strengthen the muscle or joint without irritation.

Management of OA

• Symptomatic only, emphasis on NO CURE.
• Reduce weight bearing and further injury whenever possible.
• Strengthen supporting structures to alleviate joint pain.
• Strengthening bridge muscles helps protect the joint.
• Nutritional products (glucosamine, chondroitin) may be used.
• Acetaminophen, NSAIDs, and COX inhibitors (celebrex, celecoxib) are used.
• Celecoxib is considered a gold standard.

OA - Injected Corticosteroids & Viscosupplementation

• Injected corticosteroids can be used up to 3 times per year.
• Too much injected corticosteroids can cause breakdown of protein.
• Viscosupplementation involves hyaluronate injections that reduces inflammation and pain.

NSAIDs Mechanism of Action

• COX-1 is involved in producing gastric mucosa; disrupting it can cause heartburn.
• COX-2 is an inflammatory pathway; celebrex only targets COX-2.
• Too much can cause side effects.

Glucosamine & Chondroitin

• Study results showed that glucosamine or chondroitin sulfate were not significantly better than placebo in reducing knee pain in a mild group.
• The combination of both may be slightly better than monotherapy but still not significantly different from placebo in a mild group.
• Combination therapy was effective for patients with moderate to severe pain at the start of the study.
• Celecoxib was effective for all groups.

OA Patient Profile

• Low aerobic capacity
• Avoidance of activity that hurts
• Low muscle strength
• Poor flexibility
• Poor balance
• All these factors can be improved with exercise.

Management of OA - Exercise

• No studies in humans show that exercise is detrimental.
• Evidence for benefits of exercise are stronger for knee than for hip.
• Strengthening quads slows progression of joint damage.
• Current knowledge about optimal exercises and dose-response relationship is lacking.

Exercise Testing

• Same protocols and guidelines as used for apparently healthy individuals
• Some form of dynamic warm-up
• Cardio helps tremendously, adds thermal warm-up, warming the joints
• Allow extra time for warm-up
• High-intensity exercise is contraindicated when acute inflammation
• Symptom limited
• Use visual numeric pain scale (0-10); 6/10 is a good place to stop
• Pain is subjective; stop if pain is too severe to continue

Exercise Management in OA

• Restore/maintain function of joint and prevent further degeneration.
• Protect joint from damage.
• Restore patients functional abilities.
• Walk downstairs, sit to stand.
• Reduce the risk of co-morbid conditions.

Modes of Cardiorespiratory Fitness

• Dependent on patient symptoms
• Treadmill
• Bike
• Perform daily, not just during program
• Activities are better suited as opposed to structured exercise routines
• Target several components of health-related fitness at once

Aerobic Exercise Recommendations

• The recommendations are mostly the same for most individuals, just modify as needed
• Incorporate flexibility to improve ROM and decrease stiffness
• Resistance training with a focus on switching up the program is recommended

ROM and Stretching Exercises for OA

• Perform daily.
• Stretch affected joint daily.
• Room temperature is very important.
• Apply local heat before performing.
• Cardio warm-up may help.
• Movements are repeated several times, ~10.
• Hold stretches for 10-30 seconds.

Strength Training for OA

• Improve shock attenuation and joint stability.
• If knee, train quads.
• If hip, train hip extensors (glut max, hamstrings).
• Isometric exercise good place to start with severe pain.
• If spine, focus core stabilization, minimize flexion/extension.
• Isotonic strength training, 8-12 reps, most studies use 10-15, 50-60% 1RM (up to 80% ok).
• Also 1-3 sets, 2-3x/week.
• Most importantly tailor to individual abilities.

Rheumatoid Arthritis

• A progressive, autoimmune disease.
• Cause is unknown.
• Can affect any joint.
• Usually affects joints symmetrically.
• Writs, hands, elbows, shoulders, knees, and ankles are the most commonly affected areas.
• Women are affected 2.5x more frequently.
• Most common age of onset is 40-50 years.
• Inflammation of joint synovium that thickens and interferes with joint mobility.
• Joints become swollen and painful with motion and palpating.
• Stiffness lasting for several hours in the morning is common.

Rheumatoid Arthritis - Indicators & Development

• Rheumatic factor (RF) is used as a lab indicator of disease severity.
• Erythrocyte sedimentation rate (ESR) and C-reactive protein are elevated, both inflammatory markers.
• The following typically develop from RA: eye lesions, fever, loss of appetite, anemia, ESR, whiter parts in nails (loss of blood flow), and changes in toes and fingers.

Rheumatoid Arthritis - Drug Therapy

• Initial treatment involves ibuprofen and acetaminophen.
• Then, a plan is comprised of NSAIDs, selective COX-2 inhibitors, disease-modifying anti-rheumatic agents (DMARDs), and biological agents (very expensive).

Rheumatoid Arthritis - Exercise & Guidelines

• Rheumatoid Arthritis is characterized by flare-ups and periods of remission.
• Avoid loading affected joints during flare-ups.
• Follow general guidelines as per OA.

GLA:D Program

• Good life with osteoarthritis: Denmark
• Training Program
• Used as pre-hab program to improve recovery
• 8-week education and exercise program for painful knee and/or hip osteoarthritis
• 2-3 week education sessions
• 12 neuromuscular exercise sessions

Knee Replacements

• Less invasive replacement
• Metal replacement for femoral component
• Metal tray holds joint and plastic
• Plastic and covers back of knee
• Lose all ligaments in knee depending on the replacement

Knee Replacement Divisions

• Not all replacements are equal
• Unicompartmental (partial) vs Total Knee Replacement (TKR)
• TKR is further divided into invasive vs minimally invasive.

Invasive Knee Replacement

• Patellar tendon is cut.
• Patella may be resurfaced or replaced with an implant.
• Can be cemented or uncemented.

Minimally Invasive Knee Replacement

• Tenon is not cut (quads sparing).
• Incision through quads.
• Same implants.
• Patella is pulled to the side.

Rehabilitation Implications

• Invasive: Longer rehab, tendon ruptures, documented post-op, poor patellar tracking, loss of ACL/PCL, loss of screw home
• Minimally Invasive: Potential for implant misalignment, less scar tissue, faster recovery, loss of ACL/PCL, loss of screw home
• Unicompartmental: Minimal functional deficits, ACL/PCL intact, very fast recovery, longer implant life.

Knee & Hip - Stability & Replacements

• For TKR, stability has to be created by bridging muscles.
• Only want to do 1 TKR in a lifetime.
• There are 3 hip replacement methods; recovery changes because of cutting different muscles.
• Hip replacements are done after a certain age because of implant life.
• Implants are the same, just access to area is different,.

Hip Replacement Methods - Posterior

• Incision through glut max, piriformis, gemellus, obturators, quad femoris.
• Abductor sparing.
• Lots of posterior instability.
• Patient will likely have hip precautions until follow-up.
• Avoid exercises where hip extensors are lengthened, avoid pressure posteriorly.
• Avoid deadlifts, squats, lunges, single leg balance activities until late stage rehab (8-10 weeks).

Hip Replacement Methods - Lateral

• Incision through glut med and/or glut min, sometimes vastus lateralis (depends on persons anatomy).
• Major effect on hip abductor mechanism.
• Patient will likely have hip precautions until follow-up.
• There's a lot more trauma to the muscles that were cut, resulting in limitations with rehab exercises.

Hip Replacement Methods - Anterior

• Incision over anterior groin and thigh.
• Exposure of acetabulum between sartorius and TFL.
• Exposure of femoral head between rectus femoris and glut med.
• Abductor sparing approach.
• Not all hospitals have the required table for this approach, which holds your leg at a certain angle.

Hip Precautions

• No flexion past 90
• No adduction past midline
• No internal/external rotation
• Glute med is important because it stabilizes hips during gait.