4 GoalLearn a standardized, evidence-based history and physical examination of patients with knee injuriesWHICH WILL:Enable family medicine resident physicians to accurately diagnose common knee problems throughout the full age spectrum of patients seen in family medicineAn important reason for achieving these skills is to provide patients with a correct and timely diagnosis, therefore giving them a greater chance of restoring normal pain-free use of their knee.
5 Competency-Based Objectives Patient care – focused history and examProfessionalism – respect, compassionInterpersonal and communication skills – differential diagnosisMedical knowledge base – anatomy, injury mechanismsSystems based practice – accuracy, time-efficiencyPATIENT CARE: Perform a focused history and examination of a patient with a knee-related problem/complaintPROFESSIONALISM: Provide a respectful and compassionate evaluation of the patient with a knee complaintINTERPERSONAL & COMMUNICATION SKILLS: Present a provisional working diagnosis to the patient who presents with a knee problemMEDICAL KNOWLEDGE BASE:Understand anatomy and physiology of knee joint and the relationship to pathology of knee problemsUnderstand mechanism of different types of injuries and use it to ascertain the proper diagnosisSYSTEMS-BASED PRACTICE:Appropriate utilization of imaging studies to augment the history and examination of a patient with a knee complaintConduct an accurate evaluation in a time-efficient manner
6 Assessing a knee injury Components of the assessment includeFocused historyAttentive physical examinationThoughtfully ordered tests/studiesfor future discussionNotes on Ottawa Knee Rules if question arises from learners–1. Age 55 or older2. Point tenderness at patella (no bone tenderness of knee other than patella)3. Tenderness at head of fibula.4. Knee cannot be flexed to 90 degrees5. Patient unable to bear weight for four steps immediately and in the emergency department or office.Tips for Accurate Usage:Tenderness of patella only counts if it is the only area of the bone tenderness in the kneeInability to bear weight means patient is unable to transfer weight twice onto each leg regardless of limpingSensitivity - 100%Negative predictive value 100%Specificity 49%Compared with examination, MRI more sensitive for ligamentous and meniscal damage but less specific.POTENTIAL BENEFITSReduction in the proportion of patients referred for knee radiography. In a trial implementation study, there was a relative reduction of 26.4% in the proportion of patients referred for knee radiography in the intervention group (77.6% versus 57.1%; P < .001), but a relative reduction of only 1.3% in the control group (76.9% versus 75.9%; P=.60). These changes over time were significant when the intervention and control groups were compared (P<.001).Sensitivity and reliability of the rule for detecting knee fractures. In a prospective validation study, the rule was found to have a sensitivity of 1.0 (95% confidence interval for identifying 63 clinically important fractures). The same sensitivity results were found in a trial implementation study detecting 58 knee fractures. The k coefficient for interpretation of the rule in the prospective validation study was 0.77 (95% confident interval, 0.65 to 0.89) and in the trial implementation study was 0.91 (95% confidence interval, ).Reduction in waiting time for patients and health-care costs. In a trial implementation study, those discharged without radiography spent less time in the emergency department compared with nonfracture patients who underwent radiography during the after-intervention period, (85.7 minutes versus minutes) and incurred lower estimated total medical charges for physician visits and radiography (US $80 versus US $183).Sources:Implementation of the Ottawa knee rule for the use of radiography in acute knee injuries. JAMA 1997 Dec 17;278(23):Prospective validation of a decision rule for the use of radiography in acute knee injury. JAMA 1996 Feb 28;275(8):
8 Focused History Questions Onset of PainDate of injury or when symptoms startedLocation of pain*AnteriorMedialLateralPosterior*Differential diagnosis by LOCATION:Anterior – Patellofemoral syndrome, bursitis, Osgood-Schlatter’s disease, patellar tendinitis, patellar fractureMedial – meniscus, MCL, DJD, pes anserine bursitisLateral – Meniscus, LCL, DJD, iliotibial band friction syndrome, fibular head dysfunctionPosterior – hamstring injury, tear of posterior horn of medial or lateral meniscus, Baker’s cyst, neurovascular injury (popliteal artery or nerve)
9 Focused History Questions2 Mechanism of Injury -helps predict injured structureContact or noncontact injury?*If contact, what part of the knee was contacted?Anterior blow?Valgus force?Varus force?Was foot of affected knee planted on the ground?**Valgus alignment = distal segment deviates lateral with respect to proximal segment.Patellas Touch*CONTACT INJURIES/DIRECT BLOWS:Commonly cause injury to: collateral ligaments, patellar dislocation, epiphyseal fractures in children with open growth platesValgus forces are more common than varus-directed forcesBlow to lateral aspect of knee resulting in stretch injury to soft tissues of medial knee (MCL more prone to injury than LCL)Pearl to help remember the difference between varus and valgus stress, Valgus has “L” as in lateral and patella.NONCONTACT INJURIES:Vulnerable structures:Cruciate ligaments (most common)MenisciJoint capsule**Think ACL INJURY any time you have a patient with a significant NON-CONTACT injury with foot planed on the ground (foot planted then knee twisted or body changed direction, felt a pop, immediate swelling, could not continue playing)
10 Focused History Questions3 Injury-Associated Events*Pop heard or felt?Swelling after injury (immediate vs delayed)Catching / LockingBuckling / Instability (“giving way”)POP FELT OR HEARD: Ligament or meniscus injurySWELLING AFTER INJURY=EFFUSION (intra-articular)Immediate vs delayed onset swelling/effusionImmediate refers to less than 6 hours after injury and correlates to:Cruciate ligament tearArticular fractureKnee dislocationDelayed swelling usually follows meniscal injuries50% of patients with an acute ligament rupture will experience localized edema at injury siteIn instances where swelling is less than expected:Complete ligamentous or capsular disruptionFluid exudes through tearLocalized swelling (rather than true joint swelling or effusion) can be caused by:Prepatellar bursitisMeniscal cystic changesOutgrowth of a Baker/popliteal cystDilation of an artery, such as a popliteal artery aneurysmNontraumatic Effusion - septic arthritis, tumor, gout, degenerative arthritis, synovitis, symptomatic arthriditiesCATCHING / LOCKINGKnee gets caught or stuck (“locked”) in a flexed position due to something blocking normal joint motion and person cannot voluntarily flex further.Often due to:Tear in meniscusDetached tissue lodging in knee jointInjury to cruciate ligament(s)Osteochondral fracturePseudolocking is due to pain and muscle spasm secondary to increasing edemaBUCKLING / INSTABILITY (“giving way”)Displacement of osseous components of the knee suggesting ligamentous laxity (tibia slides forward on femur when ACL deficient) or patellar instability (patella moves laterally when subluxed or dislocated) ORQuadriceps inhibition due to pain (such as during patellar subluxation or with meniscus tear) or weakness due to injuryNational Institute of Arthritis and Musculoskeletal and Skin Diseases National Institutes of Health, Article Created: , Article Updated:Cf. arthrolith and arthrophyte.
12 Focused History Questions4 Degree of Immediate Dysfunction|------------------------|Unable to Antalgic ContinuedAmbulate Gait* to Participate* Antalgic gait = A characteristic gait resulting from pain on weightbearing in which the stance phase of gait is shortened on the affected side.
13 Focused History Questions5 Aggravating FactorsActivities, changing positions, stairs, kneelingRelieving Factors/treatments triedIce, medications, crutchesHistory of previous knee injury or surgery
14 Historical Clues to Knee Injury Diagnoses Noncontact injury with “pop”ACL tearContact injury with “pop”MCL or LCL tear, meniscus tear, fractureAcute swellingACL tear, PCL tear, fracture, knee dislocation, patellar dislocationLateral blow to the kneeMCL tearMedial blow to the kneeLCL tearKnee “gave out” or “buckled”ACL tear, patellar dislocationFall onto a flexed kneePCL tear
16 Physical Exam - General Develop a standard routine*Alleviate the patient's fearsGENERAL STEPSInspectionPalpationRange of motionStrength testingSpecial tests*Use of a standardized routine for the knee exam will help insure that a complete exam is done every time
17 Physical Exam - Exposure Adequate exposure - groin to toes bilaterallyExamine in supine positionCompare knees
18 Observe – Static Alignment Patient stands facing examiner with feet shoulder width apartAnkles, subtalar joints – pronation, supinationFeet – pes planus, pes cavusPes planusPes cavus(http://www.arc.org.uk/about_arth/booklets/6012/images/6012_1.gif)(http://www.steenwyk.com/pronsup.htm)
19 Observe – Static Alignment Patient then brings medial aspects of knees and ankles in contactKnees – genu valgum (I), genu varum (II)Genu valgumGenu varum(http://www.orthoseek.com/articles/img/bowl1.gif)
20 Observe – Dynamic Alignment Pronation/Supination may be enhanced with ambulationAntalgic gait indicates significant problem (anti = against, algic = pain)
21 Inspect Knee Warmth Evidence of local trauma Erythema Effusion* AbrasionsContusionsLacerationsPatella positionMuscle atrophy*“Pearl” - Persistent or recurrent effusion is NOT normal and most likely signals internal derangement such as:Cruciate Ligament TearMeniscal TearOCD - osteochondritis dessicans - localized osteocartilaginous separation at level of subchondral bone producing pain and swellingChondral DefectFracture
22 Inspect Knee-Related Muscles Quadriceps atrophyLong-standing problemVastus medialis atrophyAfter surgery
24 Surface Anatomy - Anterior, Extended* PatellaIndentedHollowAppears hollow on either side of patellaThere is a slight indentation above the patellaA small amount of fluid will make these hollow-appearing areas disappear. Larger effusions are most conspicuous as a fullness proximal to the patella.
27 Lateral and Medial Patellar Facets Palpation – Anterior*Patella:Lateral and Medial Patellar FacetsSuperiorAndInferiorPatellar Facets*Assess for tenderness, edema, warmth**Palpate the insertion of the patellar tendon on tibial tubercle in adolescents (location of pain in Osgood-Schlatter syndrome in adolescents)Medial FatPatLateral Fat PadPatellar Tendon**
29 Palpation - Medial Medial Collateral Ligament (MCL)* Pes anserine bursa**Medial jointline*Assess for tenderness along entire course of ligament from origin on medial femoral condyle to insertion on proximal tibia.**Pes anserine bursa is about 3 finger widths inferior to the medial joint line and contains the insertion site for the sartorius, gracilis, and semitendinosis muscles
31 Palpation – Lateral* Lateral Collateral Ligament (LCL)** Lateral joint line* The LCL and joint line are more easily palpated with the knee in 90 degrees of flexion.** LCL originates on lateral femoral epicondyle and inserts on fibular head
32 Palpation - Posterior Popliteal fossa* Abnormal bulges Popliteal artery aneurysmPopliteal thrombophlebitisBaker’s cyst*Popliteal artery is only palpable structure normally in this area
33 Range Of Motion Testing Extension Flexion0º ºDescribe loss of degrees of extensionExample: “lacks 5 degrees of extension”Locking* = patient unable to fully extend or flex knee due to a mechanical blockage in the knee (i.e., loose body, bucket-handle meniscus tear)*Locking vs EffusionEffusion can hinder extension and is often confused with locking
34 Strength TestingTest knee extensors (quadriceps) and knee flexors (hamstrings)Can test both with patient in seated position, knees bent over edge of tableAsk patient to extend/straighten knee against your resistanceThen ask patient to flex/bend knee against your resistanceCompare to unaffected knee
35 Special Tests – Anterior Knee Pain Patellar apprehension test*(http://www.sportsdoc.umn.edu/Clinical_Folder/Knee_Folder/Knee_Exam/lateral%20patellar%20apprehension.htm)Patellofemoral grind test**Starting positionPush patella laterally*Patellar apprehension test:Apply firm, laterally-directed force toward medial aspect of patellaPositive test is trepidation of the patient (pain or fear that patella will dislocate)Positive test implies a preceding episode of patellar instability (subluxation or dislocation)**Patellofemoral grind testPatient supine with knees extendedExaminer’s thumb on superior patellaPt. contracts quadriceps muscleExaminer applies downward and inferior pressurePositive - pain with movement or unable to complete testPositive test suggests patellofemoral dysfunction (patellofemoral stress syndrome)
36 Special Tests - Ligaments PosteriorCruciateAnterior CruciateAssess stability of 4 knee ligaments via applied stresses** The stabilizing roles of each ligament include:The medial collateral ligament (MCL) prevents the knee from buckling inwards (valgus injury)The lateral collateral ligament (LCL) prevents the knee from buckling outwards (varus injury)The anterior cruciate ligament (ACL) prevents the tibia from sliding forward under the femurThe posterior cruciate ligament (PCL) prevents the tibial from sliding backward under the femurMedial CollateralLateral Collateral
37 Stress Testing of Ligaments Use a standard exam routineDirect, gentle pressureNo sudden forcesAbnormal testExcessive motion = laxityWhat is NORMAL motion?*Soft/mushy end point***Normal StabilityMedial and Lateral collateral ligamentsNormal test is no motion with varus and/or valgus stress with knee in neutral and 30 degrees of flexionAnterior and Posterior Cruciate Ligements control anterior/posterior motionLachman’s test assesses Anterior Cruciate Ligament:Normal test is <5mm of forward movement of tibia on femur with knee at 30 degrees of flexionAnterior and posterior drawer testing assesses ACL and PCLWith knee in 90 degrees of flexion and foot stabilized, normal test will have <5mm of anterior motion (assessing ACL) or <5mm of posterior motion (assessing PCL)** Normal end point of ligament that examiner feels with applied stress is FIRM. A soft or mushy end point implies ligament damage (stretching or complete tear).
38 Collateral Ligament Assessment *Position patient supine on table with thigh resting on edge of exam table and foot supported by examinerKnee in 30 degrees of flexion – WHY? Increased laxity of medial side of knee in extension may indicate additional damage to posterior structures (posterior joint capsule & PCL)Patient and ExaminerPosition*
39 Valgus Stress Test for MCL* *VALGUS (MCL) stressProximal hand on lateral aspect of knee holds and stabilizes thighDistal hand directs ankle laterallyAttempt to open knee joint on medial sideEstimate the medial joint space and evaluate the stiffness of motion. Positive test = Significant gap in medial aspect of knee with valgus stress = MCL injury.Laxity is graded on a 1 to 4 scale: 1+, 5mm of medial joint space opening with a firm but abnormal endpoint; 2+, 10mm medial opening with a soft endpoint; 3+ (15mm) and 4+ (20mm) may be indicative of an associated cruciate ligament injury and must be carefully examined.Note Direction Of Forces
40 Video of Valgus Stress Test Click onimage for video
41 Varus Stress Test for LCL* *VARUS (LCL) StressSupine position, with knee at 20 to 30 degrees of flexion and thigh supported.Stabilize medial aspect of knee and push ankle medially, trying to open knee joint on lateral sideDisruption of LCL is indicated by difference in degree of lateral knee tautness with varus stress. Compare affected knee to uninjured sideNote direction of forces
42 Video of Varus Stress Test Click onimage for video
43 Lachman Test* Patient Position Physician hand placement *Lachman Maneuver more sensitive and specific for ligamentous tears than drawer sign.Patient is supineKnee flexed to degreesHand placement:Grasp and stabilize patient’s thigh just proximal to patellaWith opposite hand, try to move proximal tibia forward on femurPOSITIVE TEST = Excessive forward motion of tibia (>5mm) without firm endpoint indicates ACL damageModification for patient with large thighs:Thigh placed over knee of examinerPush downward on femur with hand while other hand grasps proximal tibia, attempting to move it anteriorly
44 Lachman Test2 View from lateral aspect* Note direction of forces *View from lateral aspect shows:Concave silhouette of knee, from tibial tubercle to superior aspect of patella, which obliterates with ACL damage/positive Lachman’s maneuverNote direction of forces
47 Anterior Drawer Test for ACL Physician Position & Movements*Patient Position*Patient PositionSupineFlex hip of affected knee to 45 degreesBend knee to 90 degreesPatient's foot planted firmly on examination tablePhysician position:Sitting on dorsum of foot, place both hands behind kneeOnce hamstrings relaxed, try to displace proximal leg anteriorlyAnterior drawer test is LESS SENSITIVE for ACL damage than Lachman’s ManeuverNote direction of forces
48 Posterior Drawer Testing- PCL* *Patient PositionSupineAffected knee at 90 degrees of flexionDetermine ‘neutral’ position by comparing resting position with unaffected kneePhysician Position & MovementsPatient's foot placed between examiner's legs while the palms of the hands are used to push the tibia posteriorly.Tester directs pressure backward upon proximal tibia, similar to Anterior Drawer TestingInterpretation of test:Posterior instability - PCL injury indicated by increased posterior tibial translationConfusion - trying to distinguish abnormal translation of tibia on femur - from excessive ACL or PCL laxityNote direction of forces
49 Assess Meniscus – Knee Flexion Most sensitive test is full flexion*Examiner passively flexes the knee or has patient perform a full two-legged squat to test for meniscal injuryJoint line tenderness**Flexion of the knee enhances palpation of the anterior half of each meniscus*Full flexion: Sensitivity 55-85%, Specificity 29-67%**Joint line tendernessThis has a mean sensitivity of 76%, but mean specificity is 29%. (Jackson, Ann Int Med, 2003).
50 Tests that we do not recommend routinely Pivot-Shift* - for ACL tearMcMurray Test**- for meniscus tears* Pivot Shirt Test is seldom used, has questionable accuracySubstantiate capsular tears and injury to ACLSensitivity = 35% awake, 85% under anesthesia; Specificity has not been reported in very many studies (Solomon, et al. JAMA 2001)**McMurray test is specific (97%) but has poor sensitivity (52%) for meniscal injury; it is difficult to perform accurately, and we advocate NOT performing this test routinely.Procedure: Positioning for medial meniscusPatient supine and knee in maximum flexionExaminer palpates posteromedial margin of affected knee joint with one hand and supports foot with opposite handExaminer externally rotates lower leg as far as possible while cautiously extending the kneeIf medial meniscus tear, an audible, palpable, and painful clunk occurs as femur passes over damaged portion of meniscusPositioning for lateral meniscusExaminer places hand over posterolateral aspect of knee joint and internally rotates lower leg while fully extending the kneeClicks without pain or joint-line tenderness may represent a normal variant, especially during lateral meniscus testing
51 Review of Evidence – ACL* (Jackson JL, et al.)*The reported specificities are from very small #s of studies, as most studies evaluated test results among patients known to have the injury.Lachman Test Sens 87% Spec 93%Anterior Drawer Sens 48% Spec 87%Pivot Shift Test Sens 61% Spec 97%
52 Review of Evidence - Meniscus (Jackson JL, et al.)Joint Line Tenderness Sens 76% Spec 29%McMurray Test Sens 52% Spec 97%
53 ReferencesCalmbach WL, Hutchens M. Evaluation of Patients Presenting with Knee Pain: Part I. History, Physical Examination, Radiographs, and Laboratory Tests. Am Fam Physician 2003;68:Ebell MH. A Tool for Evaluating Patients with Knee Injury. Family Practice Management. March 2005:67-70.Jackson JL, O’Malley PG, Kroenke K. Evaluation of Acute Knee Pain in Primary Care. Ann Intern Med. 2003;139:Malanga GA, Andrus S, Nadler SF, McLean J. Physical Examination of the Knee: A Review of the Original Test Description and Scientific Validity of Common Orthopedic Tests. Arch Phys Med Rehabil 2003;84:Solomon DH, Simel DL, Bates DW, Katz JN. Does this patient have a torn meniscus or ligament of the knee? Value of the Physical Examination. JAMA 2001;286: