Knee Pain

Overview

Epidemiology

• ↑ Prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency of knee pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways with increasing age 
• ↑ Prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency of knee pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways with increasing BMI BMI An indicator of body density as determined by the relationship of body weight to body height. Bmi=weight (kg)/height squared (m2). Bmi correlates with body fat (adipose tissue). Their relationship varies with age and gender. For adults, bmi falls into these categories: below 18. 5 (underweight); 18. 5-24. 9 (normal); 25. 0-29. 9 (overweight); 30. 0 and above (obese). Obesity
• The knee is the most common joint affected by osteoarthritis Osteoarthritis Osteoarthritis (OA) is the most common form of arthritis, and is due to cartilage destruction and changes of the subchondral bone. The risk of developing this disorder increases with age, obesity, and repetitive joint use or trauma. Patients develop gradual joint pain, stiffness lasting < 30 minutes, and decreased range of motion. Osteoarthritis ( OA OA Osteoarthritis (OA) is the most common form of arthritis, and is due to cartilage destruction and changes of the subchondral bone. The risk of developing this disorder increases with age, obesity, and repetitive joint use or trauma. Patients develop gradual joint pain, stiffness lasting < 30 minutes, and decreased range of motion. Osteoarthritis). 
• Osteoarthritis Osteoarthritis Osteoarthritis (OA) is the most common form of arthritis, and is due to cartilage destruction and changes of the subchondral bone. The risk of developing this disorder increases with age, obesity, and repetitive joint use or trauma. Patients develop gradual joint pain, stiffness lasting < 30 minutes, and decreased range of motion. Osteoarthritis is the most common cause of knee pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways in people 50 years of age or older.
• Women > men
• A common complaint of runners and athletes

Anatomy of the knee joint Knee joint The knee joint is made up of the articulations between the femur, tibia, and patella bones, and is one of the largest and most complex joints of the human body. The knee is classified as a synovial hinge joint, which primarily allows for flexion and extension with a more limited degree of translation and rotation. Knee Joint: Anatomy

• Largest and most complex joint of the human body
• Synovial hinge joint
• Supporting structures include:
  • Joint capsule Capsule An envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides. Bacteroides
  • Lateral and medial menisci Menisci Meniscus Tear
  • Multiple ligaments for mobility and stability of the knee

Categories of knee pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways

• Acute knee pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways:
  • Trauma
  • Acute exacerbation of chronic knee pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
  • Infection
  • Rheumatological problem
• Chronic knee pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways:
  • Overuse
  • OA OA Osteoarthritis (OA) is the most common form of arthritis, and is due to cartilage destruction and changes of the subchondral bone. The risk of developing this disorder increases with age, obesity, and repetitive joint use or trauma. Patients develop gradual joint pain, stiffness lasting < 30 minutes, and decreased range of motion. Osteoarthritis
  • Tendinopathies
  • Patellar instability
  • Patellofemoral pain syndrome Patellofemoral pain syndrome A syndrome characterized by retropatellar or peripatellar pain resulting from physical and biochemical changes in the patellofemoral joint. The pain is most prominent when ascending or descending stairs, squatting, or sitting with flexed knees. There is a lack of consensus on the etiology and treatment. The syndrome is often confused with (or accompanied by) chondromalacia patellae, the latter describing a pathological condition of the cartilage and not a syndrome. Examination of the Lower Limbs (PFPS)
• Knee pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways without trauma:
  • Infection
  • Rheumatological etiology
  • Malignancy Malignancy Hemothorax

Clinical Presentation and Diagnosis

History

Obtaining a clear history is essential to making the correct diagnosis and guiding the examination:

• Location for common problems:
  • Anterior:
    • PFPS
    • Patellofemoral compartment osteoarthritis Osteoarthritis Osteoarthritis (OA) is the most common form of arthritis, and is due to cartilage destruction and changes of the subchondral bone. The risk of developing this disorder increases with age, obesity, and repetitive joint use or trauma. Patients develop gradual joint pain, stiffness lasting < 30 minutes, and decreased range of motion. Osteoarthritis
    • Patellar tendonitis Tendonitis Reactive Arthritis
    • Osgood-Schlatter disease Osgood-Schlatter Disease Osgood-Schlatter disease, or apophysitis of the tibial tubercle, is a common orthopedic condition seen in children between 10 and 15 years of age. The disease is caused by the repetitive application of mechanical forces on the knee, leading to microtrauma on the ossification center at the site of insertion of the distal patellar ligament. Osgood-Schlatter Disease
  • Medial:
    • Medial collateral ligament Medial collateral ligament Knee Joint: Anatomy ( MCL MCL Knee Joint: Anatomy) sprain
    • Medal compartment osteoarthritis Osteoarthritis Osteoarthritis (OA) is the most common form of arthritis, and is due to cartilage destruction and changes of the subchondral bone. The risk of developing this disorder increases with age, obesity, and repetitive joint use or trauma. Patients develop gradual joint pain, stiffness lasting < 30 minutes, and decreased range of motion. Osteoarthritis (most commonly affected compartment)
    • Medial meniscus Medial Meniscus Meniscus Tear tear
    • Pes PES Removal of plasma and replacement with various fluids, e.g., fresh frozen plasma, plasma protein fractions (ppf), albumin preparations, dextran solutions, saline. Used in treatment of autoimmune diseases, immune complex diseases, diseases of excess plasma factors, and other conditions. Thrombotic Thrombocytopenic Purpura anserine bursitis
  • Lateral:
    • Lateral meniscus tear Meniscus tear The menisci are fibrocartilaginous wedge-shaped structures between the distal femur and proximal tibia that stabilize and dissipate weight-bearing forces at the knee joint. A meniscus tear is an injury to the meniscus caused by rotational or shearing forces across the tibiofemoral joint. Meniscus Tear
    • Lateral compartment osteoarthritis Osteoarthritis Osteoarthritis (OA) is the most common form of arthritis, and is due to cartilage destruction and changes of the subchondral bone. The risk of developing this disorder increases with age, obesity, and repetitive joint use or trauma. Patients develop gradual joint pain, stiffness lasting < 30 minutes, and decreased range of motion. Osteoarthritis
    • Iliotibial band Iliotibial band Thigh: Anatomy syndrome (ITBS)
• Exacerbating and alleviating factors
• Presence of swelling Swelling Inflammation/effusion
• Mechanical symptoms (consider meniscus or cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage: Histology lesion):
  • Clicking/popping
  • Catching/locking
• Previous surgery/procedures
• Systemic signs/symptoms:
  • Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
  • Chills Chills The sudden sensation of being cold. It may be accompanied by shivering. Fever
  • Erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion
• Remember: Knee pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways may be referred from hip pathology (especially in children).

Physical examination

The exam is directed by the duration and type of injury (acute or chronic) and the age of the individual. Comparison of the healthy knee is important:

• Observation:
  • Previous surgical scars
  • Stance and gait Gait Manner or style of walking. Neurological Examination:
    • Limp
    • Inability to bear weight
  • Angular deformities:
    • Genu varum Genu varum Genu varum is a deformation of the knee joint(s) that creates angulation of the lower limb(s) away from the midline in the coronal plane. Children ages 1-5 years are commonly affected. Genu Varum (bowleg)
    • Genu valgum Genu valgum Genu valgum is a deformation of the knee joint(s) that creates angulation of the lower limb(s) toward the midline in the coronal plane. Children ages 1-5 years are commonly affected. Genu Valgum (knock-knee)
  • Swelling Swelling Inflammation, erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion, ecchymosis Ecchymosis Extravasation of blood into the skin, resulting in a nonelevated, rounded or irregular, blue or purplish patch, larger than a petechia. Orbital Fractures
  • Ability to perform a deep squat
  • Muscle atrophy Atrophy Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes. Cellular Adaptation
• Range of Motion Range of motion The distance and direction to which a bone joint can be extended. Range of motion is a function of the condition of the joints, muscles, and connective tissues involved. Joint flexibility can be improved through appropriate muscle strength exercises. Examination of the Upper Limbs (ROM):
  • Flexion Flexion Examination of the Upper Limbs: 0–135 degrees
  • Compare to the opposite side.
  • Evaluate the hip.
• Palpation Palpation Application of fingers with light pressure to the surface of the body to determine consistency of parts beneath in physical diagnosis; includes palpation for determining the outlines of organs. Dermatologic Examination:
  • Generally performed with the knee at 90 degrees of flexion Flexion Examination of the Upper Limbs while seated or supine with 20–30 degrees of flexion Flexion Examination of the Upper Limbs
  • Joint line palpation Palpation Application of fingers with light pressure to the surface of the body to determine consistency of parts beneath in physical diagnosis; includes palpation for determining the outlines of organs. Dermatologic Examination:
    • Meniscus injury
    • Collateral ligaments
    • OA OA Osteoarthritis (OA) is the most common form of arthritis, and is due to cartilage destruction and changes of the subchondral bone. The risk of developing this disorder increases with age, obesity, and repetitive joint use or trauma. Patients develop gradual joint pain, stiffness lasting < 30 minutes, and decreased range of motion. Osteoarthritis
    • Fat pad
  • Anterior:
    • Patella Patella The flat, triangular bone situated at the anterior part of the knee. Knee Joint: Anatomy
    • Patellar ligament Patellar ligament A band of fibrous tissue that attaches the apex of the patella to the lower part of the tubercle of the tibia. The ligament is actually the caudal continuation of the common tendon of the quadriceps femoris. The patella is embedded in that tendon. As such, the patellar ligament can be thought of as connecting the quadriceps femoris tendon to the tibia, and therefore it is sometimes called the patellar tendon. Osgood-Schlatter Disease
    • Patellar tendon
    • Quadriceps tendon Quadriceps tendon Knee Joint: Anatomy
    • Tibial tubercle Tibial Tubercle Osgood-Schlatter Disease
    • Prepatellar bursa Prepatellar bursa Knee Joint: Anatomy
    • Fat pad
  • Medially:
    • MCL MCL Knee Joint: Anatomy
    • Pes PES Removal of plasma and replacement with various fluids, e.g., fresh frozen plasma, plasma protein fractions (ppf), albumin preparations, dextran solutions, saline. Used in treatment of autoimmune diseases, immune complex diseases, diseases of excess plasma factors, and other conditions. Thrombotic Thrombocytopenic Purpura anserine tendons
    • Pes PES Removal of plasma and replacement with various fluids, e.g., fresh frozen plasma, plasma protein fractions (ppf), albumin preparations, dextran solutions, saline. Used in treatment of autoimmune diseases, immune complex diseases, diseases of excess plasma factors, and other conditions. Thrombotic Thrombocytopenic Purpura anserine bursitis 
  • Laterally:
    • Lateral collateral ligament Lateral collateral ligament Knee Joint: Anatomy (LCL)
    • Iliotibial band Iliotibial band Thigh: Anatomy (ITB)
    • Fibular head
  • Posterior:
    • Popliteal cyst Popliteal cyst A synovial cyst most commonly at the back of the knee. Osteoarthritis (Baker cyst)
    • Popliteal artery Popliteal Artery The continuation of the femoral artery coursing through the popliteal fossa; it divides into the anterior and posterior tibial arteries. Popliteal Fossa: Anatomy
  • Crepitus Crepitus Osteoarthritis
  • Excessive warmth
  • Effusion:
    • Ballottement of the patella Patella The flat, triangular bone situated at the anterior part of the knee. Knee Joint: Anatomy
    • “Fluid wave” for smaller effusions
  • Strength and neurovascular testing:
    • Lower extremity neurological exam
    • Assessment of distal pulses

Imaging

• Used as an adjunct to the history and physical examination
• Plain X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests clinical decision-making tools:
  • The Ottawa knee rules and the Pittsburgh knee rules are helpful in the acute care setting to decide if an individual should receive imaging of the knee.
  • Ottawa knee rules apply to individuals > 2 years of age with knee pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways/tenderness in the setting of trauma (images not needed if all negative):
    • > 55 years of age
    • Point tenderness Point Tenderness Chronic Apophyseal Injury at the head of the fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy
    • Point tenderness Point Tenderness Chronic Apophyseal Injury of the patella Patella The flat, triangular bone situated at the anterior part of the knee. Knee Joint: Anatomy
    • Flexion Flexion Examination of the Upper Limbs of the knee < 90 degrees
    • Inability to walk 4 weight-bearing steps
  • Pittsburgh knee rules apply to all individuals with an acute injury in the past week, without prior knee surgery or ED evaluation (images not needed if all negative):
    • < 12 years of age
    • > 50 years of age
    • Inability to walk 4 weight-bearing steps
• MRI:
  • Important in the assessment of soft tissue Soft Tissue Soft Tissue Abscess injuries of the knee
  • Not indicated for initial evaluation
• Ultrasound:
  • Assess soft tissues around the knee (e.g., tendons, collateral ligaments).
  • May be helpful for aspiration/injections

Differential Diagnosis of Knee Pain

The assessment of knee pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways is challenging. One approach to the differential diagnosis is to group the various conditions based on the acuteness of the presentation, the presence or absence of effusion, and the precipitating activities.

Traumatic knee injuries

Atraumatic knee injuries

Referred pain Referred Pain Spinal Disk Herniation

• Individual presents with:
  • Vaguely localized knee pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
  • No focal tenderness
  • No inflammatory signs
• Associated with disorders affecting the lumbar spine Spine The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy, sacroiliac joint Sacroiliac Joint The immovable joint formed by the lateral surfaces of the sacrum and ilium. Pelvis: Anatomy, or hip joint Hip joint The hip joint is a ball-and-socket joint formed by the head of the femur and the acetabulum of the pelvis. The hip joint is the most stable joint in the body and is supported by a very strong capsule and several ligaments, allowing the joint to sustain forces that can be multiple times the total body weight. Hip Joint: Anatomy:
  • Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways is referred from the hip (i.e., OA OA Osteoarthritis (OA) is the most common form of arthritis, and is due to cartilage destruction and changes of the subchondral bone. The risk of developing this disorder increases with age, obesity, and repetitive joint use or trauma. Patients develop gradual joint pain, stiffness lasting < 30 minutes, and decreased range of motion. Osteoarthritis in adults, slipped capital femoral epiphysis Epiphysis The head of a long bone that is separated from the shaft by the epiphyseal plate until bone growth stops. At that time, the plate disappears and the head and shaft are united. Bones: Structure and Types ( SCFE SCFE Slipped capital femoral epiphysis (SCFE) is an orthopedic disorder of early adolescence characterized by the pathologic “slipping” or displacement of the femoral head, or epiphysis, on the femoral neck. Slipped Capital Femoral Epiphysis) in adolescents).
  • Radicular pain Radicular Pain Spinal Disk Herniation: most commonly the L5, S1 S1 Heart Sounds nerve roots
• Uncommon causes of knee pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways:
  • Benign Benign Fibroadenoma and malignant bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types tumors
  • The knee is a common site.
  • Presentation:
    • Often nonspecific symptoms
    • Mimics common musculoskeletal disorders
    • Regional or localized pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
    • Fevers and swelling Swelling Inflammation of soft tissue Soft Tissue Soft Tissue Abscess
    • Night pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
    • Pathological fractures
  • The main determinants in the analysis of bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types tumors include:
    • Morphology of bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types lesion:
      • Well or ill-defined
      • Presence of sclerosis Sclerosis A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve. Wilms Tumor
    • Age of individual
  • Benign Benign Fibroadenoma bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types tumors:
    • The majority of bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types tumors are benign Benign Fibroadenoma and incidental findings.
    • May present with:
      • Swelling Swelling Inflammation
      • Deformity Deformity Examination of the Upper Limbs
      • Pathological fractures
    • More common in younger age groups
  • Malignant bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types tumors:
    • Uncommon
    • Causes significant morbidity Morbidity The proportion of patients with a particular disease during a given year per given unit of population. Measures of Health Status and mortality Mortality All deaths reported in a given population. Measures of Health Status
    • Osteosarcoma Osteosarcoma Osteosarcoma is a primary malignant tumor of the bone characterized by the production of osteoid or immature bone by the tumor cells. The disease is most common in children and young adults and most frequently affects growth plates of the long bones, although it can involve any bone. Osteosarcoma is the most common bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types cancer.
    • Bone-marrow cancers include multiple myeloma Multiple myeloma Multiple myeloma (MM) is a malignant condition of plasma cells (activated B lymphocytes) primarily seen in the elderly. Monoclonal proliferation of plasma cells results in cytokine-driven osteoclastic activity and excessive secretion of IgG antibodies. Multiple Myeloma, lymphoma Lymphoma A general term for various neoplastic diseases of the lymphoid tissue. Imaging of the Mediastinum, and leukemia.

Management

• Effective management of knee pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways is dependent on the correct diagnosis. 
• Many disorders causing knee pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways can be treated nonoperatively.
• Some injuries require operative management.

Clinical Relevance

• The knee joint Knee joint The knee joint is made up of the articulations between the femur, tibia, and patella bones, and is one of the largest and most complex joints of the human body. The knee is classified as a synovial hinge joint, which primarily allows for flexion and extension with a more limited degree of translation and rotation. Knee Joint: Anatomy is made up of articulations between the femur, tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy, and patella Patella The flat, triangular bone situated at the anterior part of the knee. Knee Joint: Anatomy bones. The knee joint Knee joint The knee joint is made up of the articulations between the femur, tibia, and patella bones, and is one of the largest and most complex joints of the human body. The knee is classified as a synovial hinge joint, which primarily allows for flexion and extension with a more limited degree of translation and rotation. Knee Joint: Anatomy is one of the largest and most complex joints of the human body. The knee is classified as a synovial hinge joint, which primarily allows for flexion Flexion Examination of the Upper Limbs and extension Extension Examination of the Upper Limbs. The supporting structures include a joint capsule Capsule An envelope of loose gel surrounding a bacterial cell which is associated with the virulence of pathogenic bacteria. Some capsules have a well-defined border, whereas others form a slime layer that trails off into the medium. Most capsules consist of relatively simple polysaccharides but there are some bacteria whose capsules are made of polypeptides. Bacteroides, the lateral and medial menisci Menisci Meniscus Tear, and multiple ligaments, which help to ensure the mobility and stability of the knee.
• Osteoarthritis Osteoarthritis Osteoarthritis (OA) is the most common form of arthritis, and is due to cartilage destruction and changes of the subchondral bone. The risk of developing this disorder increases with age, obesity, and repetitive joint use or trauma. Patients develop gradual joint pain, stiffness lasting < 30 minutes, and decreased range of motion. Osteoarthritis is due to cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage: Histology destruction and changes of the subchondral bone Subchondral Bone Osteochondritis Dissecans. The risk of developing the disorder increases with age, obesity Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity, and repetitive joint use or trauma. Individuals have joint pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, stiffness, and decreased ROM. Physical exam may reveal crepitus Crepitus Osteoarthritis with joint motion and osteophyte Osteophyte Bony outgrowth usually found around joints and often seen in conditions such as arthritis. Osteoarthritis formation. The diagnosis is clinical and supported with radiographic joint findings. Management is conservative.
• Rheumatoid arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis is a symmetric, inflammatory polyarthritis Polyarthritis Rheumatoid Arthritis. Rheumatoid arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis is a chronic, progressive, autoimmune disorder Autoimmune Disorder Septic Arthritis most commonly presenting in middle-aged women with joint swelling Swelling Inflammation, pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, and morning stiffness. The diagnosis is by the presence of rheumatoid factor Rheumatoid factor Antibodies found in adult rheumatoid arthritis patients that are directed against gamma-chain immunoglobulins. Autoimmune Hepatitis, anti-cyclic citrullinated peptide antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions, and image findings. Management involves antirheumatic drugs, biologic agents Biologic Agents Immunosuppressants, and physical therapy Physical Therapy Becker Muscular Dystrophy. 
• Gout Gout Gout is a heterogeneous metabolic disease associated with elevated serum uric acid levels (> 6.8 mg/dL) and abnormal deposits of monosodium urate in tissues. The condition is often familial and is initially characterized by painful, recurring, and usually monoarticular acute arthritis, or “gout flare,” followed later by chronic deforming arthritis. Gout is a metabolic disease associated with elevated serum uric acid Uric acid An oxidation product, via xanthine oxidase, of oxypurines such as xanthine and hypoxanthine. It is the final oxidation product of purine catabolism in humans and primates, whereas in most other mammals urate oxidase further oxidizes it to allantoin. Nephrolithiasis levels and abnormal deposits of monosodium urate in tissues. Gout Gout Gout is a heterogeneous metabolic disease associated with elevated serum uric acid levels (> 6.8 mg/dL) and abnormal deposits of monosodium urate in tissues. The condition is often familial and is initially characterized by painful, recurring, and usually monoarticular acute arthritis, or “gout flare,” followed later by chronic deforming arthritis. Gout is often familial and initially characterized by painful, recurring, monoarticular swollen joints, followed by chronic deforming arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis. Management is with NSAIDs NSAIDS Primary vs Secondary Headaches, steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors, or urate-lowering therapy.
• Calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes pyrophosphate crystal deposition disease (CPPD) occurs secondary to the deposition of calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes pyrophosphate dihydrate crystals in the periarticular tissues of joints and soft tissues. The disease, also known as pseudogout, can produce joint inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation similar to gout Gout Gout is a heterogeneous metabolic disease associated with elevated serum uric acid levels (> 6.8 mg/dL) and abnormal deposits of monosodium urate in tissues. The condition is often familial and is initially characterized by painful, recurring, and usually monoarticular acute arthritis, or “gout flare,” followed later by chronic deforming arthritis. Gout. Management is with colchicine Colchicine A major alkaloid from colchicum autumnale l. And found also in other colchicum species. Its primary therapeutic use is in the treatment of gout. Gout Drugs, NSAIDS NSAIDS Primary vs Secondary Headaches, and methotrexate Methotrexate An antineoplastic antimetabolite with immunosuppressant properties. It is an inhibitor of tetrahydrofolate dehydrogenase and prevents the formation of tetrahydrofolate, necessary for synthesis of thymidylate, an essential component of DNA. Antimetabolite Chemotherapy.
• Slipped capital femoral epiphysis Epiphysis The head of a long bone that is separated from the shaft by the epiphyseal plate until bone growth stops. At that time, the plate disappears and the head and shaft are united. Bones: Structure and Types ( SCFE SCFE Slipped capital femoral epiphysis (SCFE) is an orthopedic disorder of early adolescence characterized by the pathologic “slipping” or displacement of the femoral head, or epiphysis, on the femoral neck. Slipped Capital Femoral Epiphysis) is an orthopedic disorder of early adolescence characterized by the pathological “slipping” or displacement Displacement The process by which an emotional or behavioral response that is appropriate for one situation appears in another situation for which it is inappropriate. Defense Mechanisms of the femoral head, or epiphysis Epiphysis The head of a long bone that is separated from the shaft by the epiphyseal plate until bone growth stops. At that time, the plate disappears and the head and shaft are united. Bones: Structure and Types, on the femoral neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess. The disorder is due to a combination of biomechanical and endocrine factors. Diagnosis is made with an X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests of the hip. Treatment ranges from conservative to surgical and prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas depends on the severity of the slip or displacement Displacement The process by which an emotional or behavioral response that is appropriate for one situation appears in another situation for which it is inappropriate. Defense Mechanisms.