What is the evaluation protocol for knee pain in a healthy adult?

1.

Knee Pain (Nontraumatic), Elsevier ClinicalKey Clinical Overview

Diagnosis Clinical history and examination are integral to formulation of initial working diagnosis Key aspects include: Age of patient and history of comorbid conditions (eg, osteoarthritis) Chronicity of pain Location of pain Activities associated with pain or leading up to pain Presence of mechanical joint symptoms (eg, catching, true locking) Presence of joint effusion Pattern of tenderness on examination Caveats and cautions Relatively poor correlation exists between pain and findings on imaging; perform imaging when there is high likelihood that results may affect care Comprehensive history, examination, and appropriate provocative testing may yield correct diagnosis for intra-articular pathology in only about 56% of patients overall; shotgun use of provocative tests (use without appropriate supporting clinical context) further decreases diagnostic accuracy Exclude diagnoses requiring urgent evaluation (eg, concern for septic joint, fracture) Patients with severe pain, immediate swelling, and instability or inability to bear weight in association with acute trauma or concern for joint infection require emergent referral for urgent diagnostic and management considerations Radiographic imaging is the preferred initial imaging study, when indicated, after working diagnosis is established by clinical presentation Primary indication for patients with nontraumatic knee pain is chronic pain (lasting more than 6 weeks) Imaging for acute traumatic knee pain is indicated in patients meeting specific criteria; Pittsburgh knee rule, Ottawa knee rule, American College of Radiology Appropriateness Criteria Advanced imaging (eg, musculoskeletal ultrasonography, MRI) is indicated for persistent pain with effusion recalcitrant to adequate conservative treatment and as part of presurgical evaluation MRI is often obtained to investigate mechanical signs and symptoms and when ligamentous, meniscal, and/or cartilaginous pathology is suspected; also performed as part of presurgical planning Standard or point of care ultrasonography may be helpful when evaluating for effusion, suspicion for popliteal cyst, and superficial ligament and tendon injuries;

Synopsis Perception of pain in and around the knee may be caused by intrinsic conditions involving supporting structures of the knee (eg, joints, bones, muscles, ligaments, tendons, bursae) or referred from elsewhere (eg, hip, lumbar spine); most knee pain is caused by structures supporting the knee joint Knee pain represents the second most common musculoskeletal complaint (after back pain) presenting to a primary care setting; knee pain affects approximately 25% of adults Clinical history and examination are integral to formulation of initial working diagnosis Key aspects include patient's age and history of comorbid conditions (eg, osteoarthritis), chronicity and specific location of pain (eg, anterior, lateral, medial, diffuse), activities associated with pain or leading up to pain, presence of mechanical joint symptoms (eg, catching, true locking), presence of joint effusion, and pattern of tenderness on examination First step in diagnostic process is to exclude diagnoses requiring urgent evaluation (eg, concern for septic joint, fracture) Radiographic imaging is the preferred initial imaging study, when indicated, after working diagnosis is established by clinical presentation; primary indication for patients with nontraumatic knee pain is chronic pain (lasting more than 6 weeks) Advanced imaging (eg, musculoskeletal ultrasonography, MRI) is indicated for persistent pain recalcitrant to adequate conservative treatment and as part of presurgical evaluation Laboratory testing may play a confirmatory or diagnostic role in limited clinical scenarios such as when joint infection or inflammatory condition is suspected Arthrocentesis is indicated with concern for septic joint and may be required to confirm crystal-induced arthritis; arthroscopy may be indicated for diagnostic purposes when diagnosis remains in question after primary workup

Diagnosis Fully expose both lower limbs and compare both knees Perform tests first on unaffected leg to gain information about baseline anatomy and laxity Consider the following structures during examination: soft tissue (muscles, tendons, bursae), bone structures and alignment, collateral and cruciate ligaments, menisci, and knee articulations (medial, lateral, patellofemoral) Examine joints above (hip and lumbar spine) and below (ankle) to assess for pathology resulting in referred pain; assess for neurovascular abnormalities Presence of extra-articular findings (eg, cutaneous, pulmonary, cardiac abnormalities) may suggest a specific underlying condition in patients with suspected inflammatory arthritis Gait Antalgic gait with shortened stance phase is common in patients with painful knee condition Thrusts are not uncommon in patients with painful knee conditions Thrusts that occur during stance phase of gait are often secondary to progressive angular deformity from degenerative changes or chronic ligamentous instability Medial thrust (femur shifts medially) is commonly associated with medial collateral ligament and/or posteromedial capsular laxity Lateral thrust (femur shifts laterally) is commonly associated with lateral collateral ligament and/or posterior corner laxity Thrusts into recurvatum (back knee deformity) may occur as a result of posterior capsular laxity or quadriceps weakness Inspection Skin erythema suggests inflammation of skin or superficial bursae Swelling Diffuse and generalized swelling often indicates either joint effusion or inflammatory synovitis; asymmetrical and localized swelling often suggests bursitis or condition involving a tendon Unilateral swelling may indicate joint effusion or bursitis; bilateral joint involvement suggests systemic inflammatory condition or bilateral osteoarthritis Small effusion usually results in distal swelling noted on medial aspect of knee as obliteration of medial peripatellar dimple

Diagnosis Suspected inflammatory conditions Standard initial testing includes erythrocyte sedimentation rate, C-reactive protein, and CBC with differential Suspected autoimmune conditions Standard initial screening tests include rheumatoid factor and autoantibodies (eg, antineutrophil antibody) Examination of arthrocentesis fluid Includes microscopic examination for gouty crystals and evidence of bacterial infection (eg, cell counts, Gram stain) along with culture

2.

Simel, David L. (2024). In Goldman-Cecil Medicine (pp. 28). DOI: 10.1016/B978-0-323-93038-3.00006-X

The patient’s symptoms direct the musculoskeletal examination (Chapters 236and242). Most patients have back pain at some point during their life (Chapter 369). The patient’s history helps assess the likelihood of an underlying systemic disease (age, history of systemic malignancy, unexplained weight loss, duration of pain, responsiveness to previous therapy, intravenous drug use, urinary infection, or fever). The most important physical examination findings for lumbar disc herniation in patients with sciatica are ipsilateral straight leg raising causing pain, contralateral straight leg raising causing pain, and ankle or great toe dorsiflexion weakness. Evaluation of hip motion and pain during motion helps detect hip osteoarthritis. The generalist physician should evaluate an adult patient with knee discomfort for torn menisci or ligaments. A variety of maneuvers assess for pain, popping, or grinding along the joint line between the femur and tibia to evaluate for meniscal tears. A tear in the ligaments eliminates a discrete endpoint when the anterior, medial, or posterior ligaments are stressed. As with many musculoskeletal disorders, no single finding has the accuracy of the orthopedist’s examination, which factors in the history and a variety of clinical findings. The shoulder examinationis directed toward determining range of motion, maneuvers that cause discomfort, and assessment of functional disability. Hip osteoarthritis is detected by evidence of restriction of internal rotation and abduction of the affected hip. The degree of pain and disability experienced by the patient may prompt confirmation of the diagnosis and referral. The hands and feetmay show evidence of osteoarthritis (local or as part of a systemic process) (Chapter 241), rheumatoid arthritis (Chapter 243), gout (Chapter 252), or other connective tissue diseases.

3.

Knee Injury (Other Than Dislocation or Fracture), Elsevier ClinicalKey Clinical Overview

Synopsis The knee is a complex and frequently injured joint Most acute knee injuries (93.5%) involve soft tissue damage—including ligament, tendon, and meniscal tears—rather than osseous injuries A comprehensive focused history is imperative in the diagnostic process; enables narrowing of the differential diagnosis Systematic evaluation includes visual inspection, palpation, range of motion, neurovascular status, motor strength, and tests for specific pathologic abnormalities; using combination of findings is more reliable than specific testing alone Relevant patient history and physical examination tests often provide information to make a provisional diagnosis Provisional diagnosis informs need for further investigation and referral Radiographs are the initial imaging study of choice to identify fractures or dislocations requiring emergent care Clinical decision rules for fracture identification can help decrease number of unnecessary knee radiographs (eg, Ottawa and Pittsburgh knee rules) Consider additional imaging modalities (eg, MRI, CT, ultrasonography) as clinically indicated Initial treatment of undifferentiated soft tissue knee injury Generally consists of knee rest, ice, compression, elevation, pain management, and appropriate referral Ultimate management is injury- and patient-specific and may be conservative or surgical Physical therapy/rehabilitation is an important component of most treatments, regardless of initial approach Helps restore function and strengthen supporting musculature Complications include vascular and nerve injury, infection, and osteoarthritis Prognosis varies; depends on nature and severity of injury, treatment, individual patient parameters, expectations, and goals

4.

Bunt CW, Jonas CE, Chang JG. American Family Physician. 2018;98(9):576-585.

Publish date: November 4, 2018.

Knee pain affects approximately 25% of adults, and its prevalence has increased almost 65% over the past 20 years, accounting for nearly 4 million primary care visits annually. Initial evaluation should emphasize excluding urgent causes while considering the need for referral. Key aspects of the patient history include age; location, onset, duration, and quality of pain; associated mechanical or systemic symptoms; history of swelling; description of precipitating trauma; and pertinent medical or surgical history. Patients requiring urgent referral generally have severe pain, swelling, and instability or inability to bear weight in association with acute trauma or have signs of joint infection such as fever, swelling, erythema, and limited range of motion. A systematic approach to examination of the knee includes inspection, palpation, evaluation of range of motion and strength, neurovascular testing, and special (provocative) tests. Radiographic imaging should be reserved for chronic knee pain (more than six weeks) or acute traumatic pain in patients who meet specific evidence-based criteria. Musculoskeletal ultrasonography allows for detailed evaluation of effusions, cysts (e.g., Baker cyst), and superficial structures. Magnetic resonance imaging is rarely used for patients with emergent cases and should generally be an option only when surgery is considered or when a patient experiences persistent pain despite adequate conservative treatment. When the initial history and physical examination suggest but do not confirm a specific diagnosis, laboratory tests can be used as a confirmatory or diagnostic tool.