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Knee osteoarthritis

Evaluation and Treatment of Knee Pain: A Review

Author/s: 
Win Min Oo, Changhai Ding, Adam G. Culvenor, David J. Hunter

Importance: Approximately 5% of all primary care visits in adults are related to knee pain. Osteoarthritis (OA), patellofemoral pain, and meniscal tears are among the most common causes of knee pain.

Observations: Knee OA, affecting an estimated 654 million people worldwide, is the most likely diagnosis of knee pain in patients aged 45 years or older who present with activity-related knee joint pain with no or less than 30 minutes of morning stiffness (95% sensitivity; 69% specificity). Patellofemoral pain typically affects people younger than 40 years who are physically active and has a lifetime prevalence of approximately 25%. The presence of anterior knee pain during a squat is approximately 91% sensitive and 50% specific for patellofemoral pain. Meniscal tears affect an estimated 12% of the adult population and can occur following acute trauma (eg, twisting injury) in people younger than 40 years. Alternatively, a meniscal tear may be a degenerative condition present in patients with knee OA who are aged 40 years or older. The McMurray test, consisting of concurrent knee rotation (internal or external to test lateral or medial meniscus, respectively) and extension (61% sensitivity; 84% specificity), and joint line tenderness (83% sensitivity; 83% specificity) assist diagnosis of meniscal tears. Radiographic imaging of all patients with possible knee OA is not recommended. First-line management of OA comprises exercise therapy, weight loss (if overweight), education, and self-management programs to empower patients to better manage their condition. Surgical referral for knee joint replacement can be considered for patients with end-stage OA (ie, no or minimal joint space with inability to cope with pain) after using all appropriate conservative options. For patellofemoral pain, hip and knee strengthening exercises in combination with foot orthoses or patellar taping are recommended, with no indication for surgery. Conservative management (exercise therapy for 4-6 weeks) is also appropriate for most meniscal tears. For severe traumatic (eg, bucket-handle) tears, consisting of displaced meniscal tissue, surgery is likely required. For degenerative meniscal tears, exercise therapy is first-line treatment; surgery is not indicated even in the presence of mechanical symptoms (eg, locking, catching).

Conclusions and Relevance: Knee OA, patellofemoral pain, and meniscal tears are common causes of knee pain, can be diagnosed clinically, and can be associated with significant disability. First-line treatment for each condition consists of conservative management, with a focus on exercise, education, and self-management.

Keywords 
Arthralgia Knee Joint Knee pain Magnetic Resonance Imaging Knee osteoarthritis osteoarthritis Patellofemoral Pain Syndrome Tibial Meniscus Injuries meniscal tear

Effect of Physical Therapy vs Arthroscopic Partial Meniscectomy in People With Degenerative Meniscal Tears: Five-Year Follow-up of the ESCAPE Randomized Clinical Trial

Author/s: 
Noordyun, J. C. A., Van de Graaf, V. A., Willigenburg, N. W., Scholten-Peeters, G. G. M., Kret, E. J., Van Dijk, R. A., Buchbinder, R., Hawker, G. A., Coppieters, M. W., Poolman, R. W., ESCAPE Research Group

Importance: There is a paucity of high-quality evidence about the long-term effects (ie, 3-5 years and beyond) of arthroscopic partial meniscectomy vs exercise-based physical therapy for patients with degenerative meniscal tears.

Objectives: To compare the 5-year effectiveness of arthroscopic partial meniscectomy and exercise-based physical therapy on patient-reported knee function and progression of knee osteoarthritis in patients with a degenerative meniscal tear.

Design, setting, and participants: A noninferiority, multicenter randomized clinical trial was conducted in the orthopedic departments of 9 hospitals in the Netherlands. A total of 321 patients aged 45 to 70 years with a degenerative meniscal tear participated. Data collection took place between July 12, 2013, and December 4, 2020.

Interventions: Patients were randomly allocated to arthroscopic partial meniscectomy or 16 sessions of exercise-based physical therapy.

Main outcomes and measures: The primary outcome was patient-reported knee function (International Knee Documentation Committee Subjective Knee Form (range, 0 [worst] to 100 [best]) during 5 years of follow-up based on the intention-to-treat principle, with a noninferiority threshold of 11 points. The secondary outcome was progression in knee osteoarthritis shown on radiographic images in both treatment groups.

Results: Of 321 patients (mean [SD] age, 58 [6.6] years; 161 women [50.2%]), 278 patients (87.1%) completed the 5-year follow-up with a mean follow-up time of 61.8 months (range, 58.8-69.5 months). From baseline to 5-year follow-up, the mean (SD) improvement was 29.6 (18.7) points in the surgery group and 25.1 (17.8) points in the physical therapy group. The crude between-group difference was 3.5 points (95% CI, 0.7-6.3 points; P < .001 for noninferiority). The 95% CI did not exceed the noninferiority threshold of 11 points. Comparable rates of progression of radiographic-demonstrated knee osteoarthritis were noted between both treatments.

Conclusions and relevance: In this noninferiority randomized clinical trial after 5 years, exercise-based physical therapy remained noninferior to arthroscopic partial meniscectomy for patient-reported knee function. Physical therapy should therefore be the preferred treatment over surgery for degenerative meniscal tears. These results can assist in the development and updating of current guideline recommendations about treatment for patients with a degenerative meniscal tear.

Keywords 
physical therapy Arthroscopic Partial Meniscectomy clinical trial Knee osteoarthritis Degenerative Meniscal Tear

Cost-effectiveness of Physical Therapy vs Intra-articular Glucocorticoid Injection for Knee Osteoarthritis: A Secondary Analysis From a Randomized Clinical Trial

Author/s: 
Rhon, D. I., Kim, M., Asche, C. V., Allison, S. C., Allen, C. S., Deyle, G. D.

Importance: Physical therapy and glucocorticoid injections are initial treatment options for knee osteoarthritis, but available data indicate that most patients receive one or the other, suggesting they may be competing interventions. The initial cost difference for treatment can be substantial, with physical therapy often being more expensive at the outset, and cost-effectiveness analysis can aid patients and clinicians in making decisions.

Objective: To investigate the incremental cost-effectiveness between physical therapy and intra-articular glucocorticoid injection as initial treatment strategies for knee osteoarthritis.

Design, setting, and participants: This economic evaluation is a secondary analysis of a randomized clinical trial performed from October 1, 2012, to May 4, 2017. Health economists were blinded to study outcomes and treatment allocation. A randomized sample of patients seen in primary care and physical therapy clinics with a radiographically confirmed diagnosis of knee osteoarthritis were evaluated from the clinical trial with 96.2% follow-up at 1 year.

Interventions: Physical therapy or glucocorticoid injection.

Main outcomes and measures: The main outcome was incremental cost-effectiveness between 2 alternative treatments. Acceptability curves of bootstrapped incremental cost-effectiveness ratios (ICERs) were used to identify the proportion of ICERs under the specific willingness-to-pay level ($50 000-$100 000). Health care system costs (total and knee related) and health-related quality-of-life based on quality-adjusted life-years (QALYs) were obtained.

Results: A total of 156 participants (mean [SD] age, 56.1 [8.7] years; 81 [51.9%] male) were randomized 1:1 and followed up for 1 year. Mean (SD) 1-year knee-related medical costs were $2113 ($4224) in the glucocorticoid injection group and $2131 ($1015) in the physical therapy group. The mean difference in QALY significantly favored physical therapy at 1 year (0.076; 95% CI, 0.02-0.126; P = .003). Physical therapy was the more cost-effective intervention, with an ICER of $8103 for knee-related medical costs, with a 99.2% probability that results fall below the willingness-to-pay threshold of $100 000.

Conclusions and relevance: A course of physical therapy was cost-effective compared with a course of glucocorticoid injections for patients with knee osteoarthritis. These results suggest that, although the initial cost of delivering physical therapy may be higher than an initial course of glucocorticoid injections, 1-year total knee-related costs are equivalent, and greater improvement in QALYs may justify the initial higher costs.

Keywords 
physical therapy Knee osteoarthritis Randomized Clinical Trial Glucocorticoid Injection

Total knee replacement after high tibial osteotomy: time-to-event analysis and predictors

Author/s: 
Primeau, Codie A., Birmingham, Trevor B., Leitch, Kristyn M., Willits, Kevin R., Litchfield, Robert B., Fowler, Peter J., Marsh, Jacquelyn D., Chesworth, Bert M., Dixon, Stephanie N., Bryant, Dianne M., Giffin, J. Robert

BACKGROUND: An important aim of high tibial osteotomy (HTO) is to prevent or delay the need for total knee replacement (TKR). We sought to estimate the frequency and timing of conversion from HTO to TKR and the factors associated with it.

METHODS: We prospectively evaluated patients with osteoarthritis (OA) of the knee who underwent medial opening wedge HTO from 2002 to 2014 and analyzed the cumulative incidence of TKR in July 2019. The presence or absence of TKR on the HTO limb was identified from the orthopedic surgery reports and knee radiographs contained in the electronic medical records for each patient at London Health Sciences Centre. We used cumulative incidence curves to evaluate the primary outcome of time to TKR. We used multivariable Cox proportional hazards analysis to assess potential preoperative predictors including radiographic disease severity, malalignment, correction size, pain, sex, age, body mass index (BMI) and year of surgery.

RESULTS: Among 556 patients who underwent 643 HTO procedures, the cumulative incidence of TKR was 5% (95% confidence interval [CI] 3%–7%) at 5 years and 21% (95% CI 17%–26%) at 10 years. With the Cox proportional hazards multivariable model, the following preoperative factors were significantly associated with an increased rate of conversion: radiographic OA severity (adjusted hazard ratio [HR] 1.96, 95% CI 1.12–3.45), pain (adjusted HR 0.85, 95% CI 0.75–0.96)], female sex (adjusted HR 1.67, 95% CI 1.08–2.58), age (adjusted HR 1.50 per 10 yr, 95% CI 1.17–1.93) and BMI (adjusted HR 1.31 per 5 kng/m2, 95% CI 1.12–1.53).

Keywords 
Knee Replacement Osteotomy Pain Knee osteoarthritis

Stepped Exercise Program for Patients With Knee Osteoarthritis: A Randomized Controlled Trial

Author/s: 
Allen, Kelli D., Bongiorni, Dennis, Caves, Kevin, Coffman, Cynthia J., Floegel, Theresa A., Greysen, Heather M., Hall, Katherine S., Heiderscheit, Bryan, Hoenig, Helen M., Huffman, Kim M., Morey, Miriam D., Ramasunder, Shalini, Severson, Herbert, Smith, Battista, Van Houtven, Courtney, Woolson, Sandra

Background: Physical therapy (PT) and other exercise-based interventions are core components of care for knee osteoarthritis (OA), but both are underutilized, and some patients have limited access to PT services. This clinical trial is examining a STepped Exercise Program for patients with Knee OsteoArthritis (STEP-KOA). This model of care can help to tailor exercise-based interventions to patient needs and also conserve higher resource services (such as PT) for patients who do not make clinically relevant improvements after receiving less costly interventions.

Methods / design: Step-KOA is a randomized trial of 345 patients with symptomatic knee OA from two Department of Veterans Affairs sites. Participants are randomized to STEP-KOA and Arthritis Education (AE) Control groups with a 2:1 ratio, respectively. STEP-KOA begins with 3 months of access to an internet-based exercise program (Step 1). Participants not meeting response criteria for clinically meaningful improvement in pain and function after Step 1 progress to Step 2, which involves bi-weekly physical activity coaching calls for 3 months. Participants not meeting response criteria after Step 2 progress to in-person PT visits (Step 3). Outcomes will be assessed at baseline, 3, 6 and 9 months (primary outcome time point). The primary outcome is the Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC), and secondary outcomes are objective measures of physical function. Linear mixed models will compare outcomes between the STEP-KOA and AE control groups at follow-up. We will also evaluate patient characteristics associated with treatment response and conduct a cost-effectiveness analysis of STEP-KOA.

Discussion: STEP-KOA is a novel, efficient and patient-centered approach to delivering exercise-based interventions to patients with knee OA, one of the most prevalent and disabling health conditions. This trial will provide information on the effectiveness of STEP-KOA as a novel potential model of care for treatment of OA.

Keywords 
osteoarthritis Knee osteoarthritis Knee Joint veterans exercise therapy
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