Knee Osteoarthritis
Knee osteoarthritis (OA), also known as degenerative joint disease, gonarthrosis or wear-and-tear arthritis of the knee, is a chronic condition characterized by gradual deterioration and loss of articular cartilage in the knee joint. The condition is most common in older adults and can be divided into two types: primary and secondary.
Primary Knee Osteoarthritis
Primary knee osteo
arthritis refers to osteoarthritis without an identifiable underlying cause. It is often considered part of the aging process, with gradual wear of the joint over time.
Secondary Knee Osteoarthritis
Secondary knee osteoarthritis develops as a result of an underlying condition that affects the structure or function of the joint. This may include abnormal joint loading, such as post-traumatic osteoarthritis after an injury, or systemic diseases such as rheumatoid arthritis (RA), which can affect joint cartilage.
Knee osteoarthritis is a painful chronic condition. Osteoarthritis can affect not only the knee joint but also other joints such as the hands, hips and spine. Symptom severity varies between individuals, and the disease usually progresses gradually over time.
Common clinical symptoms of knee osteoarthritis:
Intermittent or constant knee pain: Pain typically develops gradually and becomes worse with physical activity.
Morning stiffness: Stiffness in the knee joint that usually lasts less than 30 minutes.
Swelling: Swelling or inflammation around the knee.
Pain after prolonged sitting or rest: Discomfort after long periods of inactivity.
Crepitus: A grinding, cracking or popping sensation during movement, associated with degenerative changes in the joint surfaces.
Knee locking or giving way: A feeling of instability in the knee that may cause it to suddenly give way.
Difficulty walking or performing daily activities: Problems with activities such as climbing stairs, walking or completing household tasks.
Treatment:
Treatment of knee osteoarthritis generally begins with conservative management and may progress to surgical options when necessary.
Conservative treatment: Lifestyle modification, physiotherapy, pain-relieving medication such as nonsteroidal anti-inflammatory drugs (NSAIDs), and weight management to reduce joint loading.
Surgical treatment: This may be considered when conservative treatment does not provide sufficient benefit. Surgical options may include arthroscopy, osteotomy or total knee replacement, depending on the severity and characteristics of the condition.
Although medication can help manage symptoms and reduce progression of inflammatory diseases such as rheumatoid arthritis, there are currently no established disease-modifying treatments for knee osteoarthritis.
Epidemiology
Knee osteoarthritis (OA) is one of the most common joint diseases worldwide, and the knee is among the joints most frequently affected[4]. It primarily affects people over the age of 45.
OA can cause pain and loss of function, but not everyone with radiographic evidence of knee OA has symptoms. In one study, only 15% of patients with radiographic knee OA had symptoms[2][4].
OA affects nearly 6% of all adults. Women are more commonly affected than men[4]. Approximately 13% of women and 10% of men over 60 have symptomatic knee osteoarthritis[2]. Among people older than 70, prevalence may be as high as 40%[2]. Prevalence is expected to continue increasing as life expectancy and obesity rates rise[5].
Etiology
Knee osteoarthritis (OA) is classified as either primary or secondary depending on the cause[4].
Primary knee osteoarthritis is degeneration of the articular cartilage without a known underlying cause. It is generally regarded as degeneration associated with age, wear and cumulative loading.
Secondary knee osteoarthritis is degeneration of the articular cartilage caused by an identifiable condition. Possible causes of secondary knee osteoarthritis include:
Obesity
Joint hypermobility or instability
Joint malalignment, for example valgus or varus alignment
Previous joint injury, such as a fracture involving the articular surface (tibial plateau fracture)
Congenital abnormalities
Immobilization and loss of mobility
Family history
Metabolic causes, such as rickets
Infectious arthritis
Psoriatic arthritis
Hemophilia
Paget disease
Sickle cell anemia
Scoliosis
Hemochromatosis
Chondrocalcinosis
Ochronosis
Wilson disease
Gout
Pseudogout
Acromegaly
Avascular necrosis[6]
Risk Factors
Risk factors for knee osteoarthritis can be divided into modifiable and non-modifiable factors. Modifiable risk factors include BMI, trauma to the knee joint, muscle weakness or imbalance, metabolic conditions and occupations involving prolonged sitting or repeated knee flexion. Non-modifiable risk factors include sex, age, family history and ethnicity[6].
Relevant Anatomy
The knee (articulatio genus) is a synovial joint consisting of two articulations:
Tibiofemoral joint is formed between the convex femoral condyles and the relatively concave tibial condyles and is the primary articulation of the knee[7].
Patellofemoral joint is formed between the femur and the patella.
Osteoarthritis can occur in either or both of these articulations. The patellofemoral joint may be affected early in the disease process[8].
Pathological Process
The osteoarthritic process affects the articular cartilage, which consists predominantly of type II collagen, covering the articular surfaces of the bone[2].
Articular cartilage is normally maintained through a healthy biochemical balance between anabolic and catabolic processes. When osteoarthritis begins to develop, this balance becomes disrupted, leading to changes in the collagen structure of the cartilage[9][10]:
Disruption of this balance results in a disorganized collagen pattern and loss of elasticity in the articular cartilage.
This leads to fissures and tears in the cartilage and subsequent erosion of the articular surface[2].
Damaged cartilage has limited capacity to restore its original structure.
The cartilage may continue to deteriorate over time.
As cartilage is lost, the underlying bony surfaces become increasingly affected.
The bone may remodel and enlarge, and osteophytes can develop.
Ligament laxity and muscle atrophy may also develop as the disease progresses[11].
Clinical Features / Presentation
Signs and symptoms of knee osteoarthritis (OA) include:
Pain with movement
Stiffness, particularly morning stiffness
Loss of mobility
Pain after prolonged sitting or lying down
Tenderness on palpation of the joint line
Joint enlargement[12].
Diagnosis
Diagnosis may be made through clinical assessment and can be supported or confirmed with radiographic imaging.
Knee OA can be divided into five grades:
Grade 0: This represents a normal knee without radiographic evidence of osteoarthritis.
Grade 1: Very minor osteophyte formation, usually without pain or discomfort.
Grade 2: This is often the stage at which symptoms first become noticeable. A person may experience pain after a long day of walking and increased joint stiffness. This represents mild osteoarthritis, although radiographs may already show more definite osteophyte formation. Joint-space width and cartilage thickness may still be relatively preserved.
Grade 3: Moderate OA. Pain with movement becomes more frequent, and joint stiffness is more noticeable, particularly after prolonged sitting and in the morning. The cartilage between the bones shows clear damage, and the joint space becomes narrower.
Grade 4: This is the most severe stage of OA. The joint space between the bones is markedly reduced, the cartilage is almost completely lost, and synovial fluid may be reduced. This stage is usually associated with high levels of pain and discomfort during walking or joint movement[13].
Diagnostic Tests
Blood tests: Used to help determine the type of arthritis and exclude other causes.
Physical examination: See below for details.
X-ray: Standard radiographs are used to assess cartilage loss indirectly through joint-space narrowing, osteophyte formation and other bony changes, and to help exclude other causes of pain in the affected joint.
Arthrocentesis: A procedure that can be performed in a medical setting. A sterile needle is used to collect synovial fluid, which can then be analyzed for infection, crystals such as urate, and other abnormalities.
Arthroscopy: A surgical technique in which a camera is inserted into the affected joint to provide direct visualization of intra-articular structures and damage.
MRI (Magnetic Resonance Imaging): Provides detailed images of cartilage and other structures and may identify early abnormalities associated with osteoarthritis[14].
Radiographic Findings in Osteoarthritis (OA)
Joint-space narrowing: An early radiographic feature of osteoarthritis that appears as reduced space between the articulating bones.
Osteophyte formation: Bony spurs may form around the joint, particularly along the margins of the articulating bones.
Subchondral sclerosis: Increased bone density beneath the cartilage as a response to increased loading, often appearing as a more radiopaque area on X-ray.
Subchondral cysts: Cyst-like lesions can develop in the bone beneath the cartilage and may be visible on radiographs[2].
Early stages of OA may show minimal and uneven joint-space narrowing. In severe OA, the joint space can become almost completely lost (see image 2)[12].
Treatment
Treatment of knee osteoarthritis can be divided into conservative and surgical management.
Initial treatment generally begins with conservative measures, while surgery is considered when conservative management is no longer effective. A wide range of non-surgical approaches is available for knee osteoarthritis.
The main goals of osteoarthritis management are to promote self-management, reduce pain, optimize function and address the disease process and its consequences[15].
Conservative Treatment Options for Knee Osteoarthritis
The primary approach to knee osteoarthritis (OA) is conservative management, including physiotherapy focused on:
Patient education
Exercise therapy
Activity modification
Weight-management advice
Knee braces
Physiotherapy generally begins with patient education and exercise therapy as first-line treatment for all patients with symptomatic knee osteoarthritis. A combination of supervised exercise and a home-exercise program has been associated with the best outcomes. These benefits may diminish after approximately six months if exercise is discontinued[16].
Weight loss is important throughout the course of knee osteoarthritis and is particularly relevant for patients with a body mass index (BMI) above 25. A combination of dietary management and low-impact aerobic exercise is commonly recommended. Research suggests that even modest weight loss may provide meaningful benefits. Each 1% reduction in body weight has been associated with a 2% lower risk of knee-replacement surgery and a 3% lower risk of hip-replacement surgery[17].
Knee braces may be used in knee osteoarthritis to unload and redistribute forces across the affected knee joint. This can be particularly useful in selected patients with valgus or varus malalignment.
Pharmacological treatment may also be helpful for patients with symptomatic knee osteoarthritis. Common options include:
Acetaminophen (paracetamol)
Nonsteroidal anti-inflammatory drugs (NSAIDs)
COX-2 inhibitors
Glucosamine and chondroitin sulfate
Corticosteroid injections
Hyaluronic acid (HA)
Medication together with physiotherapy may be used in symptomatic knee osteoarthritis. Many NSAIDs are available, but caution is required because of potential adverse effects[18]. Glucosamine and chondroitin sulfate are dietary supplements and structural components of articular cartilage; however, strong evidence of clinically meaningful benefit in knee osteoarthritis is lacking.
Intra-articular injections such as corticosteroids may provide short-term symptom relief in selected patients with knee osteoarthritis. Hyaluronic acid (HA) injections are intended to improve joint lubrication and may provide pain relief and functional improvement in some patients, although treatment response varies.
Differential Diagnosis of Knee Osteoarthritis
Meniscal pathology
Patellofemoral pain syndrome
Gout and pseudogout
Rheumatoid arthritis
Septic arthritis[19]
Hip osteoarthritis (OA)
Referred pain from the lumbar spine
Ligament injuries such as ACL or PCL rupture
Assessment
Subjective Assessment
A thorough medical history is important, including information about when the pain began, whether onset was gradual or sudden, and whether there have been previous injuries to the same knee.
Common subjective symptoms of knee osteoarthritis include:
Early-morning stiffness
Dull, aching pain
Pain after sitting
Pain after increased activity
Reduced mobility
Difficulty bearing weight on the affected leg
Reduced ability to perform daily activities
Sleep disturbance (appropriate red-flag screening should be performed)
Patients may also experience difficulty walking, climbing stairs and/or performing household tasks, particularly tasks involving prolonged standing, sitting or walking. Some patients may also report that the knee gives way or locks[1].
Objective Assessment
After a thorough subjective assessment, the likely diagnosis may already be apparent. However, an objective examination is still necessary to evaluate differential diagnoses and obtain objective outcome measures such as range of motion (ROM).
Observation of the knee:
The knee may appear enlarged, swollen or red if the osteoarthritis is highly reactive or irritated.
General observation:
Movement patterns at rest and during simulated daily activities, such as sitting down and standing up from a chair, can provide useful clinical information.
Gait assessment:
Walking aids may be required because of pain. Assess for stiffness during gait and whether weight-bearing through the affected knee is substantially reduced.
Palpation:
Swelling, temperature changes and joint-line tenderness may be present during an acute exacerbation of knee OA.
ROM (Range of Motion):
Flexion and extension may be limited because of stiffness, pain or osteophyte formation within the joint.
Strength:
Reduced strength is common in knee osteoarthritis because of pain, reduced activity and deconditioning.
Functional activities:
Activities such as stair climbing may be impaired.
Balance testing:
Balance may be affected by pain and reduced lower-limb function, and should be assessed when fall risk is a concern.
Outcome Measures
Several outcome measures for patients with knee osteoarthritis are described in the literature. One of the most commonly used is the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). WOMAC was developed by Bellamy and colleagues in 1982. A systematic review reported excellent reliability and good validity. WOMAC is divided into three subscales—pain, stiffness and physical function—and contains 24 items, each commonly rated on an ordinal scale[20].
Physiotherapy Management
Physiotherapy should be initiated for all patients diagnosed with osteoarthritis (OA)[21].
Pain is a common symptom and varies in intensity between individuals; it does not necessarily correlate with the radiographic severity or progression of OA[22].
Exercise has been shown to be effective for short-term pain relief and improvement in physical function[12][23]. Exercise should initially be supervised by a physiotherapist, and once the patient has been properly instructed, it can be continued at home. Research has suggested that group exercise combined with a home-exercise program may be particularly effective[24].
The Role of Physiotherapy
Education
Understanding what osteoarthritis (OA) is
Explaining pain associated with OA
Explaining long-term treatment and management of OA
Educating the patient about activity modification
Promoting weight reduction when appropriate
Encouraging an active and healthy lifestyle
Exercise
Helps reduce knee pain and may reduce symptoms associated with inflammation
Helps maintain or improve knee range of motion
Strengthens the lower kinetic chain
Reduces cardiovascular risk through increased physical activity
Improves proprioception, agility and balance
Promotes physical function
Land-based exercise is suitable for most patients and is strongly recommended[25]. Activities such as aquatic exercise, stationary cycling and walking are generally safe and effective low-impact activities that avoid unnecessary loading of the knee joint[15].
Exercise also provides benefits for comorbid conditions and general health. Walking, strength training, cycling, yoga and Tai Chi are examples. An individualized exercise program should initially be developed by a physiotherapist, taking the patient's goals and preferred activities into account to support long-term adherence.
Movement or physical activity is a central component of management for people with knee osteoarthritis. Physical activity can improve joint mobility and quality of life and may also help reduce symptoms of depression[15]. People with knee OA often focus on strengthening the muscles around the knee while overlooking the hip musculature. Patients with knee OA may show hip weakness and can be exposed to increased loading of the medial knee compartment. Research indicates that hip-strengthening exercises may provide benefits, including pain reduction and improved hip strength. Hip strengthening is relevant because it can improve lower-limb mechanics and potentially reduce stress on the knee[26].
Quadriceps-strengthening exercises have been shown to improve pain and function in patients with knee OA[27]. Hip strengthening should also be considered. A high-quality systematic review found that strengthening the hip abductors had a positive effect on pain and function in patients with knee OA[28]. One study comparing hip- and knee-strengthening exercises with combined PRP and hyaluronic-acid therapy found that exercise was superior to the combination therapy for improving gait, pain and function in patients with knee OA[29].
In addition to strengthening exercises, flexibility exercises are also commonly recommended for patients with knee OA. Hamstring flexibility may be reduced in this population. Adding hamstring stretching to strengthening has shown additional benefit for reducing pain and improving function[30]. A study comparing two home-exercise programs—one combining stretching and strengthening and the other using strengthening alone—reported significantly greater improvements in pain and function with the combined program[30]. Proprioceptive neuromuscular facilitation (PNF) stretching of the hamstrings has also been reported to reduce pain and improve hamstring flexibility and general health in patients with knee OA[31].
A recent systematic review published in Rheumatology Advances in Practice evaluated factors associated with fatigue in people with hip and/or knee OA. It found strong or moderate evidence that a high burden of comorbidity and modifiable factors such as greater depression, lower self-reported physical function, higher pain and lower physical activity are associated with greater fatigue. These may therefore represent potential treatment targets. The review found moderate evidence of no association between fatigue and several sociodemographic factors, BMI or radiographic OA severity, while evidence was conflicting for poorer performance-based physical function, anxiety, joint stiffness, poor sleep and low social support[32].
Other Interventions
Several therapeutic interventions may be useful for patients, with varying levels of evidence supporting their use:
Hydrotherapy - This may be particularly useful when pain is high or conventional land-based exercise is difficult to tolerate. Aquatic exercise can help improve strength and reduce stiffness while reducing weight-bearing load on the knee[34][35].
Taping - Taping may provide short-term support or unloading. A systematic review found that elastic taping did not produce a significant improvement in WOMAC pain scores in patients with primary knee osteoarthritis, suggesting that alternative conservative treatments should be considered if symptoms persist[36].
Manual therapy - Manual therapy may improve range of motion (ROM)[37]. A systematic review reported that techniques such as mobilization with movement, passive joint mobilization and patellar mobilization can reduce knee pain and improve function. Further research is needed to establish long-term effects in knee OA[38]. Patellar mobilization has been associated with improvements in WOMAC scores, pain, stiffness and function[39]. Manual therapy directed at the hip and knee in combination with exercise has also been associated with improvements in WOMAC and physical-performance outcomes[40].
Massage - Massage may help some patients with short-term symptom control, although the evidence for effectiveness is limited[41].
Bracing - Bracing may help support or unload the knee, particularly in selected patients with valgus or varus malalignment.
Electrotherapy - Modalities such as neuromuscular electrical stimulation for quadriceps activation and TENS for pain relief have some evidence of benefit[42]. A randomized controlled trial published in 2019 reported that TENS applied to the affected knee using a symmetrical biphasic current with a sweep from 1 to 250 Hz and a pulse width of 60 μs improved pain and 6-minute walk distance[43]. Another study from the same year reported that low-intensity TENS combined with pulsed ultrasound was more effective than TENS alone for pain and disability related to knee OA[44]. A 2020 study using similar TENS parameters reported improved stair-climbing ability in people with mild knee OA[45]. For interferential current, a recent systematic review and meta-analysis of randomized controlled trials reported improvements in short- and long-term pain and short-term function[46].
Dry needling - A systematic review and meta-analysis of randomized controlled trials found very low-quality evidence of short-term positive effects on pain and function[47].
Toe-out gait modification - Increasing toe-out during walking may have positive effects in knee OA. A 2023 study reported that toe-out gait reduced medial meniscal extrusion associated with the second peak of the knee-adduction moment[48]. Increased medial meniscal extrusion appears to increase loading of the medial knee compartment and may contribute to pain and progression of knee OA[49]. A 2014 pilot study reported that 10 weeks of toe-out gait retraining reduced pain and improved WOMAC scores in people with knee OA[50].
Therapeutic ultrasound - A systematic review suggests that therapeutic ultrasound used alongside other physiotherapy interventions may reduce pain and improve function in patients with knee OA, although the evidence is limited by the small number and methodological quality of included studies. For details of treatment parameters, see the studies included in that review[51].
Low-Level Laser Therapy (LLLT) - A systematic review reported that LLLT may reduce pain and improve function in patients with knee OA. Specific treatment parameters varied across the included studies[52].
Use of Electrophysical Agents in Knee Osteoarthritis Rehabilitation
Transcutaneous Electrical Nerve Stimulation (TENS): One study reported that a 40-minute TENS session produced post-stimulation analgesia and pain reduction, using continuous dual-channel stimulation at 100 Hz with a pulse width of approximately 200 μs[53].
Therapeutic ultrasound (US): Patients receiving ultrasound treatment at 1 MHz, 1 W/cm², continuous mode for 8 minutes showed improvements in morning stiffness, 6-minute walking distance and several pain and function measures. Yeğin et al. (2017) noted that larger and more rigorous studies are needed to clarify the role of ultrasound in knee OA management[54].
Pulsed Electromagnetic Fields (PEMF): According to a Cochrane review, electromagnetic-field therapies may provide mild pain relief in people with osteoarthritis. More research is needed to determine whether they produce clinically meaningful improvements in function or quality of life[55].
Neuromuscular Electrical Stimulation (NMES): A systematic review by Giggins et al. (2012), including 409 participants, found unclear evidence regarding the effects of NMES on quadriceps strength, function and pain in knee OA. A randomized controlled trial by Sabharwal et al. (2024) reported that combining exercise with NMES may improve function, fall risk, range of motion, balance and pain management[56][57].
Shortwave Therapy (SWT): A systematic review and meta-analysis by Lee et al. (2014) reported that pulsed shortwave therapy was effective for pain relief and functional improvement, whereas continuous shortwave therapy was not. Capacitive shortwave therapy was associated with improvements in muscle strength, function and pain[58].
Extracorporeal Shockwave Therapy (ESWT): Li et al. (2018) reported that ESWT using 3,000 pulses at 15 Hz and the study's specified energy settings, applied over the joint line and medial synovial region, may be safe and effective for patients with knee OA[59].
High-Intensity Laser Therapy (HILT): A systematic review by Justina et al. (2018) reported treatment fluences ranging from 0.51 to 120 J/cm² and total energy of approximately 1,250 to 3,000 J per treatment. HILT was reported as potentially useful for knee OA[60].
Low-Level Laser Therapy (LLLT): A 2024 systematic review and meta-analysis reported that wavelengths around 904–905 nm showed potential benefits for reducing knee OA pain, although the overall quality of evidence was low[61].
Interferential Current Therapy (IFC): A randomized controlled trial published in 2021 reported improved knee OA pain intensity with interferential current combined with photobiomodulation or photobiomodulation alone. The interferential-current parameters included a strong but non-painful amplitude, 4,000 Hz carrier frequency, 50–100 Hz amplitude-modulated frequency, and four electrodes in a quadripolar configuration for 30 minutes per day, three days per week[62].
Electroacupuncture: A 2024 randomized controlled trial identified potentially useful electroacupuncture points including ST35, EX-LE5, LR8, GB33 and an Ashi point corresponding to the patient's most painful area[63].
Phonophoresis: Patients with knee OA treated with dexamethasone gel delivered with therapeutic ultrasound using continuous mode, 1 MHz, 1 W/cm² for 10 minutes showed greater improvements in pain and function in the cited study[64].
Iontophoresis: Ajediran (2014) used 50 mL of a 5% ibuprofen solution to saturate the negative electrode and water to moisten the positive electrode. The cited protocol used continuous galvanic current with specified current density and waveform parameters for 30 minutes and reported favorable results for knee OA impairments[65].
Diadynamic current: Patrícia et al. (2024) reported that exercise programs combined with diadynamic current produced greater improvements in pain and disability than exercise alone. Stationary plate electrodes were positioned medially and laterally around the knee, with treatment parameters adjusted to the individual's response[66].
Medical Treatment
When conservative treatment is insufficient to control knee osteoarthritis symptoms, procedural or surgical interventions may be considered. Common options, from less to more invasive, include:
Therapeutic injections: These may include corticosteroid, hyaluronic acid or platelet-rich plasma (PRP) injections intended to reduce pain and improve symptoms.
Arthroscopy: Arthroscopy may be used for selected mechanical intra-articular pathology, although routine arthroscopy for uncomplicated degenerative knee OA is generally not the primary treatment approach. The original source describes removal of osteophytes and degenerative meniscal pathology in selected cases[67].
High tibial osteotomy: This may be an option for appropriately selected patients when correction of lower-limb alignment can redistribute load away from a worn knee compartment.
Patellofemoral arthroplasty: If disease is isolated to the patellofemoral joint and the tibiofemoral compartments are relatively preserved, patellofemoral arthroplasty may be considered.
Unicompartmental knee arthroplasty: If osteoarthritis is confined to a single tibiofemoral compartment, unicompartmental knee arthroplasty may be considered to preserve the unaffected parts of the joint.
Total Knee Arthroplasty (TKA): This is the most extensive reconstructive option and involves replacement of the knee joint when osteoarthritis is advanced and other treatment options are insufficient.
Conclusion
Knee OA should initially be managed conservatively. If symptoms remain unacceptable and there is appropriate clinical and radiographic evidence of OA, surgical options may be considered to reduce long-term pain and improve quality of life.
There is currently no cure that reverses established knee OA, so management focuses on symptoms, function and reducing modifiable risk factors. Treatment usually begins with conservative approaches and progresses to surgical treatment when appropriate.
A multidisciplinary approach can support a healthy lifestyle and pain management, with physiotherapists, dietitians, pharmacists and medical clinicians playing complementary roles. Referral to an orthopedic specialist may be appropriate when symptoms remain severe despite adequate conservative treatment.
Sources
Lespasio M. Knee Osteoarthritis: A Primer. The Permanente Journal [Internet]. 2017;21(4). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5638628/
Hsu H, Siwiec RM. Knee Osteoarthritis. 2019. Available from:https://www.ncbi.nlm.nih.gov/books/NBK507884/ (last accessed 28.2.2020)
Bioventus. Stages of knee OA. Available from: https://www.youtube.com/watch?v=BBqjltHNOrc&feature=youtu.be (last accessed 17.11.2019)
Michael JW, Schlüter-Brust KU, Eysel P. The epidemiology, etiology, diagnosis, and treatment of osteoarthritis of the knee. Deutsches Arzteblatt International. 2010 Mar;107(9):152.
Cui A, Li H, Wang D, Zhong J, Chen Y, Lu H. Global, regional prevalence, incidence and risk factors of knee osteoarthritis in population-based studies. EClinicalMedicine. 2020 Dec 1;29:100587.
Hsu H, Siwiec RM. Knee Osteoarthritis [Internet]. Nih.gov. StatPearls Publishing; 2023. Available from: https://www.ncbi.nlm.nih.gov/books/NBK507884/
Jennifer Reft. Knee Osteokinematics and Arthokinematics. Available from: http://www.youtube.com/watch?v=EyhiCvWER0Y [last accessed 07/12/2014]
Brukner P, Clarsen B, et al. Brukner & Khan's Clinical Sports Medicine. 5th ed. McGraw Hill Education; 2017; p. 777.
Buckwalter JA, Mankin HJ, Grodzinsky AJ. Articular cartilage and osteoarthritis. Instructional Course Lectures-American Academy of Orthopaedic Surgeons. 2005;54:465.
Pearle AD, Warren RF, Rodeo SA. Basic science of articular cartilage and osteoarthritis. Clinics in Sports Medicine. 2005 Jan 1;24(1):1-2.
E. Schulte, et al. General anatomy and musculoskeletal system, Atlas of Anatomy, 2006: 372-373.
RK Arya, Vijay Jain, Osteoarthritis of the knee joint: An overview, Journal Indian Academy of Clinical Medicine, 2013, 14(2):154-62.
Lespasio MJ, Piuzzi NS, Husni ME, Muschler GF, Guarino AJ, Mont MA. Knee osteoarthritis: a primer. The Permanente Journal. 2017;21.
Osteoarthritis Diagnosis Arthritis Foundation. Available from: https://www.arthritis.org/about-arthritis/types/osteoarthritis/diagnosing.php (last accessed 17.11.2019)
Schlenk EA, Xiaojun Shi BS. Evidence based practices for osteoarthritis management. American Nurse Today. 2019;14.
Collins NJ, Hart HF, Mills KA. Osteoarthritis year in review 2018: rehabilitation and outcomes. Osteoarthritis and Cartilage. 2019 Mar 1;27(3):378-91.
Salis Z, Sainsbury A, Keen HI, Gallego B, Jin X. Weight loss is associated with reduced risk of knee and hip replacement: a survival analysis using Osteoarthritis Initiative data. International Journal of Obesity [Internet]. 2022 Jan 11;46(4):874–84.
Aweid O, Haider Z, Saed A, Kalairajah Y. Treatment modalities for hip and knee osteoarthritis: A systematic review of safety. Journal of Orthopaedic Surgery. 2018 Nov 8;26(3):2309499018808669.
E. Ringdahl, et al. Treatment of Osteoarthritis. American Family Physician. 2011;83(11):1287-1292.
Samuel AJ, Kanimozhi D. Outcome measures used in patients with knee osteoarthritis: With special importance on functional outcome measures. International Journal of Health Sciences [Internet]. 2019;13(1):52–60. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6392485/
National Institute for Health and Care Excellence (NICE). Management of osteoarthritis [Internet]. London: NICE; 2019 [updated 2020, cited May 2020]. NICE pathways. Available from: https://pathways.nice.org.uk/pathways/osteoarthritis#path=view%3A/pathways/osteoarthritis/management-of-osteoarthritis.xml&content=view-node%3Anodes-core-treatments-information-exercise-and-weight-loss
M. Elboim-Gabyzon, N. Rozen, and Y. Laufer. Gender Differences in Pain Perception and Functional Ability in Subjects with Knee Osteoarthritis. ISRN Orthopedics. Volume 2012, Article ID 413105, 4 pages.
McAlindon TE, Bannuru R, Sullivan MC, Arden NK, Berenbaum F, Bierma-Zeinstra SM, Hawker GA, Henrotin Y, Hunter DJ, Kawaguchi H, Kwoh K. OARSI guidelines for the non-surgical management of knee osteoarthritis. Osteoarthritis and Cartilage. 2014 Mar 1;22(3):363-88.
McCarthy CJ, Mills PM, Pullen R, Richardson G, Hawkins N, Roberts CR, Silman AJ, Oldham JA. Supplementation of a home-based exercise programme with a class-based programme for people with osteoarthritis of the knees: a randomised controlled trial and health economic analysis. Health Technology Assessment (Winchester, England). 2004;8:2015.
RACGP Guidelines for hip and knee arthritis Available from: https://www.racgp.org.au/download/Documents/Guidelines/Musculoskeletal/guideline-for-the-management-of-knee-and-hip-oa-2nd-edition.pdf (last accessed 18.11.2019)
Neelapala YR, Bhagat M, Shah P. Hip Muscle Strengthening for Knee Osteoarthritis: A Systematic Review of Literature. Journal of Geriatric Physical Therapy. 2020 Apr 1;43(2):89-98.[1]
DeVita P, Aaboe J, Bartholdy C, Leonardis JM, Bliddal H, Henriksen M. Quadriceps-strengthening exercise and quadriceps and knee biomechanics during walking in knee osteoarthritis: A two-centre randomized controlled trial. Clinical Biomechanics. 2018 Nov;59:199–206.
Thomas DT, R S, Prabhakar AJ, Dineshbhai PV, Eapen C. Hip abductor strengthening in patients diagnosed with knee osteoarthritis - a systematic review and meta-analysis. BMC Musculoskeletal Disorders [Internet]. 2022 Jun 29 [cited 2022 Aug 5];23(1):622. Available from: https://pubmed.ncbi.nlm.nih.gov/35768802/
Ma C, Li X, Pan Y, Tian H, Wang Z, Zhang X, et al. The efficacy of the leg swing and quadriceps strengthening exercises versus platelet-rich plasma and hyaluronic acid combination therapy for knee osteoarthritis: A retrospective comparative study. Medicine [Internet]. 2023 Sep 15 [cited 2023 Nov 14];102(37):e35238.
Suzuki Y, Iijima H, Tashiro Y, Kajiwara Y, Zeidan H, Shimoura K, et al. Home exercise therapy to improve muscle strength and joint flexibility effectively treats pre-radiographic knee OA in community-dwelling elderly: a randomized controlled trial. Clinical Rheumatology. 2018 Aug 30;38(1):133–41.
Anjum N, Sheikh RK, Omer A, Anwar K, Khan MMH, Aftab A, et al. Comparison of instrument-assisted soft tissue mobilization and proprioceptive neuromuscular stretching on hamstring flexibility in patients with knee osteoarthritis. PeerJ [Internet]. 2023;11:e16506. Available from: https://pubmed.ncbi.nlm.nih.gov/38054019/?fbclid=IwAR2NFlgQYPFvarwrfmDjP7fsiVt76Q_gZs3FNkx0LtBohTOges_d_EMSsz4
Fawole HO, Idowu OA, Abaraogu UO, Dell’Isola A, Riskowski JL, Oke KI, Adeniyi AF, Mbada CE, Steultjens MP, Chastin SF. Factors associated with fatigue in hip and/or knee osteoarthritis: a systematic review and best evidence synthesis. Rheumatology Advances in Practice. 2021;5(1):rkab013.
Good Exercise Guide. 10 Best Exercises for Knee Arthritis, Full Physio Sequence. Available from: https://www.youtube.com/watch?v=syBi8gw4dsA [last accessed 14/09/2014]
Silva LE, Valim V, Pessanha AP, Oliveira LM, Myamoto S, Jones A, Natour J. Hydrotherapy versus conventional land-based exercise for the management of patients with osteoarthritis of the knee: a randomized clinical trial. Physical Therapy. 2008 Jan 1;88(1):12-21.
Hinman RS, Heywood SE, Day AR. Aquatic physical therapy for hip and knee osteoarthritis: results of a single-blind randomized controlled trial. Physical Therapy. 2007 Jan 1;87(1):32-43.
Heddon S, Saulnier N, Mercado J, Shalmiyev M, Berteau JP. Systematic review shows no strong evidence regarding the use of elastic taping for pain improvement in patients with primary knee osteoarthritis. Medicine. 2021 Apr 2;100(13).
Deyle GD, Allison SC, Matekel RL, Ryder MG, Stang JM, Gohdes DD, Hutton JP, Henderson NE, Garber MB. Physical therapy treatment effectiveness for osteoarthritis of the knee: a randomized comparison of supervised clinical exercise and manual therapy procedures versus a home exercise program. Physical Therapy. 2005 Dec 1;85(12):1301-17.
Tsokanos A, Livieratou E, Billis E, Tsekoura M, Tatsios P, Tsepis E, Fousekis K. The Efficacy of Manual Therapy in Patients with Knee Osteoarthritis: A Systematic Review. Medicina. 2021 Jul;57(7):696.
Sit RWS, Chan KKW, Zou D, Chan DCC, Yip BHK, Zhang DD, et al. Clinic-Based Patellar Mobilization Therapy for Knee Osteoarthritis: A Randomized Clinical Trial. The Annals of Family Medicine [Internet]. 2018 Nov [cited 2019 Aug 13];16(6):521–9. Available from: http://www.annfammed.org/content/16/6/521.full
Abbott JH, Robertson MC, Chapple C, Pinto D, Wright AA, Leon de la Barra S, et al. Manual therapy, exercise therapy, or both, in addition to usual care, for osteoarthritis of the hip or knee: a randomized controlled trial. 1: clinical effectiveness. Osteoarthritis and Cartilage. 2013 Apr;21(4):525–34.
Perlman AI, Sabina A, Williams AL, Njike VY, Katz DL. Massage therapy for osteoarthritis of the knee: a randomized controlled trial. Archives of Internal Medicine. 2006 Dec 11;166(22):2533-8.
Mascarin NC, Vancini RL, dos Santos Andrade M, de Paiva Magalhães E, de Lira CA, Coimbra IB. Effects of kinesiotherapy, ultrasound and electrotherapy in management of bilateral knee osteoarthritis: prospective clinical trial. BMC Musculoskeletal Disorders. 2012 Dec 1;13(1):182.
Shimoura K, Iijima H, Suzuki Y, Aoyama T. Immediate Effects of Transcutaneous Electrical Nerve Stimulation on Pain and Physical Performance in Individuals With Preradiographic Knee Osteoarthritis: A Randomized Controlled Trial. Archives of Physical Medicine and Rehabilitation [Internet]. 2019 Feb [cited 2019 Sep 5];100(2):300-306.e1. Available from: https://www.sciencedirect.com/science/article/pii/S0003999318313728
Iijima H, Eguchi R, Shimoura K, Yamada K, Aoyama T, Takahashi M. Transcutaneous Electrical Nerve Stimulation Improves Stair Climbing Capacity in People with Knee Osteoarthritis. Scientific Reports. 2020 Apr 29;10(1).
Iijima H, Eguchi R, Shimoura K, Yamada K, Aoyama T, Takahashi M. Transcutaneous Electrical Nerve Stimulation Improves Stair Climbing Capacity in People with Knee Osteoarthritis. Scientific Reports. 2020 Apr 29;10(1).
Chen HL, Yang FA, Lee TH, Liou TH, Escorpizo R, Chen HC. Effectiveness of interferential current therapy in patients with knee osteoarthritis: a systematic review and meta-analysis of randomized controlled trials. Scientific Reports. 2022 Jun 11;12(1).
Jiménez-del-Barrio S, Medrano-de-la-Fuente R, Hernando-Garijo I, Mingo-Gómez MT, Estébanez-de-Miguel E, Ceballos-Laita L. The Effectiveness of Dry Needling in Patients with Hip or Knee Osteoarthritis: A Systematic Review and Meta-Analysis. Life. 2022 Oct 11;12(10):1575.
Hashizume T, Ishii Y, Ishikawa M, Nakashima Y, Kamei G, Iwamoto Y, et al. Toe-out gait inhibits medial meniscus extrusion associated with the second peak of knee adduction moment during gait in patients with knee osteoarthritis. Asia-Pacific Journal of Sports Medicine, Arthroscopy, Rehabilitation and Technology. 2023 Jul 1;33:13–9.
Hashizume T, Ishii Y, Ishikawa M, Nakashima Y, Kamei G, Iwamoto Y, et al. Toe-out gait inhibits medial meniscus extrusion associated with the second peak of knee adduction moment during gait in patients with knee osteoarthritis. Asia-Pacific Journal of Sports Medicine, Arthroscopy, Rehabilitation and Technology. 2023 Jul 1;33:13–9.
Hunt MA, Takacs J. Effects of a 10-week toe-out gait modification intervention in people with medial knee osteoarthritis: a pilot, feasibility study. Osteoarthritis and Cartilage. 2014 Jul;22(7):904–11.
Dantas LO, Osani MC, Bannuru RR. Therapeutic ultrasound for knee osteoarthritis: A systematic review and meta-analysis with GRADE quality assessment. Brazilian Journal of Physical Therapy [Internet]. 2021 Sep 9;25(6).
Stausholm MB, Naterstad IF, Joensen J, Lopes-Martins RÁB, Sæbø H, Lund H, et al. Efficacy of low-level laser therapy on pain and disability in knee osteoarthritis: systematic review and meta-analysis of randomised placebo-controlled trials. BMJ Open [Internet]. 2019 Oct [cited 2019 Nov 11];9(10):e031142. Available from: https://bmjopen.bmj.com/content/9/10/e031142
Cheing, G. L. Y., Tsui, A. Y. Y., Lo, S. K., & Hui-Chan, C. W. Y. (2003). OPTIMAL STIMULATION DURATION OF TENS IN THE MANAGEMENT OF OSTEOARTHRITIC KNEE PAIN. Journal of Rehabilitation Medicine, 35(2), 62–68. https://doi.org/10.1080/16501970306116
Yeğin, T., Altan, L., & Aksoy, M. K. (2016). The Effect of Therapeutic Ultrasound on Pain and Physical Function in Patients with Knee Osteoarthritis. Ultrasound in Medicine & Biology, 43(1), 187–194. https://doi.org/10.1016/j.ultrasmedbio.2016.08.035
Li, S., Yu, B., Zhou, D., He, C., Zhuo, Q., & Hulme, J. M. (2013). Electromagnetic fields for treating osteoarthritis. Cochrane Library. https://doi.org/10.1002/14651858.cd003523.pub2
Giggins, O., Fullen, B., & Coughlan, G. (2012). Neuromuscular electrical stimulation in the treatment of knee osteoarthritis: a systematic review and meta-analysis. Clinical Rehabilitation, 26(10), 867–881. https://doi.org/10.1177/0269215511431902
Sabharwal, J., & Joshi, S. (2024). Effectiveness of neuromuscular exercises and neuromuscular electrical stimulation on pain, function and balance in patients with knee osteoarthritis – a randomised controlled trial. Comparative Exercise Physiology, 20(3), 263–271. https://doi.org/10.1163/17552559-20230047
Lee, J. H. I. (2014). Effectiveness of shortwave therapy in management of knee osteoarthritis: A systematic review and meta-analysis of randomized controlled trials. https://koreascience.kr/article/JAKO201435051110558.page
Li, W., Pan, Y., Yang, Q., Guo, Z., Yue, Q., & Meng, Q. (2018). Extracorporeal shockwave therapy for the treatment of knee osteoarthritis. Medicine, 97(27), e11418. https://doi.org/10.1097/md.0000000000011418
Wyszyńska, J., & Bal-Bocheńska, M. (2018). Efficacy of High-Intensity Laser Therapy in Treating Knee Osteoarthritis: A First Systematic Review. Photomedicine and Laser Surgery, 36(7), 343–353. https://doi.org/10.1089/pho.2017.4425
Fan, T., Li, Y., Wong, A. Y. L., Liang, X., Yuan, Y., Xia, P., Yao, Z., Wang, D., Pang, M. Y. C., Ding, C., Zhu, Z., Li, Y., & Fu, S. N. (2024). A systematic review and network meta-analysis on the optimal wavelength of low-level light therapy (LLLT) in treating knee osteoarthritis symptoms. Aging Clinical and Experimental Research, 36(1). https://doi.org/10.1007/s40520-024-02853-0
Alqualo-Costa, R., Rampazo, É. P., Thome, G. R., Perracini, M. R., & Liebano, R. E. (2021). Interferential current and photobiomodulation in knee osteoarthritis: A randomized, placebo-controlled, double-blind clinical trial. Clinical Rehabilitation, 35(10), 1413–1427. https://doi.org/10.1177/02692155211012004
Wang, X., Wang, R., Liu, Q., Shi, G., Mi, B., Liu, C., Tu, J., & Lin, J. (2024). Electroacupuncture versus exercise in patients with knee osteoarthritis: Study protocol for a randomized controlled trial. PLoS ONE, 19(6), e0305105. https://doi.org/10.1371/journal.pone.0305105
Ahmed, M. a. S., Saweeres, E. S. B., Abdelkader, N. A., Abdelmajeed, S. F., & Fares, A. R. (2019). Improved Pain and Function in Knee Osteoarthritis with Dexamethasone Phonophoresis: A Randomized Controlled Trial. Indian Journal of Orthopaedics, 53(6), 700–707. https://doi.org/10.4103/ortho.ijortho_639_18
Bello, A. I., & Kuwornu, S. (2014). 5% Ibuprofen Iontophoresis Compared with Transcutaneous Electrical Nerve Stimulation in the Management of Knee Osteoarthritis: A Feasibility Study. Open Journal of Therapy and Rehabilitation, 02(04), 166–172. https://doi.org/10.4236/ojtr.2014.24022
Alfredo, P. P., Johnson, M. I., Bjordal, J. M., Santos, A. T. S., Peres, G. B., Steagall, W., Junior, & Casarotto, R. A. (2024). Efficacy of diadynamic currents as an adjunct to exercise to manage symptoms of knee osteoarthritis in adults: A randomized controlled clinical trial. Clinical Rehabilitation, 38(7), 920–931. https://doi.org/10.1177/02692155241236611
National Institute for Health and Care Excellence (NICE). Osteoarthritis: care and management [Internet]. London: NICE; 2008. Updated Feb 2014, cited May 2020. Clinical guideline [CG177]. Available from: https://www.nice.org.uk/guidance/cg177/chapter/1-Recommendations#referral-for-consideration-of-joint-surgery-2
Mayo Clinic. Mayo Clinic's Approach to Knee Arthritis - Both Surgical and Non-Surgical. Available from: https://www.youtube.com/watch?v=4Mk9GZ7-Dz8 (last accessed 17.11.2019)
