Presentation on theme: "Calvary Health Care Sydney"— Presentation transcript:
1Calvary Health Care Sydney KNEE PAINUpdated May 2013
2Outline Knee pain and common causes Differential diagnosis Baker’s CystOsgood-Schlatter LesionACL & PCLExaminationInvestigations
3Knee PainKnee pain is a common presenting complaint with many possible causes.Teenage girls and young women: more likely to have patellar tracking problems such as patellar subluxation and patellofemoral pain syndrome.Teenage boys and young men: more likely to have knee extensor mechanism problems such as tibial apophysitis (Osgood-Schlatter lesion) and patellar tendonitis.Older adults: Osteoarthritis of the knee joint is common.Referred pain resulting from hip joint pathology, such as slipped capital femoral epiphysis, also may cause knee pain.Active patients: more likely to have acute ligamentous sprains and overuse injuries such as pes anserine bursitis and medial plica syndrome.Trauma: may result in acute ligamentous rupture or fracture, leading to acute knee joint swelling and hemarthrosis. Septic arthritis may develop in patients of any age, but crystal-induced inflammatory arthropathy is more likely in adults.
4Common Causes of Knee Pain by Age Group Children and AdolescentsAdultsOlder AdultsPatellar subluxationPatellofemoral pain syndrome (chondromalacia patellae)OsteoarthritisTibial apophysitis (Osgood-Schlatter lesion)Medial plica syndrome Crystal-induced inflammatory arthropathy: gout, pseudogoutJumper's knee (patellar tendonitis)Pes anserine bursitisPopliteal cyst (Baker's cyst)Referred pain: slipped capital femoral epiphysisTrauma: ligamentous sprains (anterior cruciate, medial collateral, lateral collateral), meniscal tearOsteochondritis dissecansInflammatory arthropathy: rheumatoid arthritis, Reiter's syndromeSeptic arthritis
5Causes of Acute Knee Pain CommonLess CommonNot to be missedMedial Meniscus TearPatellar tendon ruptureFracture of the Tibial PlateauMCL SprainAcute Patellofemoral Joint InjuryAvulsion fractureACL ruptureCoronary Ligament SprainOsteochondritis DissecansLateral Meniscus TearBursal hematoma / bursitisReflex Sympathetic Dystrophy (post injury)Articular Cartilage InjuryAcute fat pad impingementPCL SprainLow Quadriceps HaematomaPatellar DislocationAvulsion of Biceps Femoris TendonDislocated Superior Tibiofibular Joint
6Surrounding Musculature Muscles surrounding the knee joint further contribute to knee stabilization during lower extremity movementsPrimary muscles include the quadriceps anteriorly, hamstrings posteriorly, gluteus medius and tensor fascia lata/IT band laterally and the hip adductors mediallyThe repetitive, eccentric nature of muscular activity about the knee during sports may lead to fatigue related injuries
7Differential Diagnosis of Knee Pain by Anatomic Site Anterior Knee PainPosterior Knee PainPatellar subluxation or dislocationPopliteal cyst (Baker's cyst)Tibial apophysitis (Osgood-Schlatter lesion)Posterior cruciate ligament injuryJumper's knee (patellar tendonitis)Patellofemoral pain syndrome (chondromalacia patellae)
8Differential Diagnosis of Knee Pain by Anatomic Site Medial Knee PainLateral Knee PainMedial collateral ligament sprainLateral collateral ligament sprainMedial meniscal tearLateral meniscal tearPes anserine bursitisIliotibial band tendonitisMedial plica syndrome
9The Relationship of Swelling to Diagnosis ImmediateDelayedNo Swelling0-2 Hours (hemarthrosis)ACL rupturePatellar Dislocation6-24 hours (effusion)MeniscusMCL SprainThe degree and time of onset of welling is an important diagnostic clue
11Baker’s Cyst Definition: A Chronic Knee Joint effusion A Baker cyst, also called a popliteal cyst, is a synovial cyst located posterior to the medial femoral condyle between the tendons of the medial head of the gastrocnemius and semimembranosus muscles. It results from the abnormal collection of fluid inside the gastrocnemio-semimembranosus bursa.A Baker cyst is lined by a true synovium, as it is an extension of the knee joint.Popliteal cysts range from 1-40 cm3 (median 3 cm3).
12Symptoms of Baker’s Cyst FrequencyPopliteal Mass or Swelling29/3876%Aching12/3832%Knee EffusionThrombophlebitis5/3813%Clicking of the knee4/3811%Buckling of the kneeLocking of the knee1/383%There may be limitation in range of motion caused by pain or by the size of the cyst.
13Popliteal Mass The most common presenting complaint or symptom It is usually visible as a bulge behind the knee, which is particularly noticeable on standing and comparing to the opposite uninvolved knee. They are generally soft and minimally tenderBaker cysts can become complicated by protrusion of fluid down the leg between the muscles of the calf (dissection). The cyst can rupture, leaking fluid down the medial leg to sometimes give the medial ankle the appearance of a painless bruise. Baker cyst dissection and rupture are frequently associated with swelling of the leg and can mimic phlebitis of the leg
14Phlebitis in the LegInflammation of a vein, leading to the formation of a thrombus in the veinWill cause the leg to swell with oedema fluid and feel stiff and painfulSignificant number of patients (13%) have symptoms simulating deep venous thrombosis (DVT), a syndrome termed pseudothrombophlebitisTherefore, exclude DVT in patients with popliteal cyst and leg swellingA blood clot may be dangerous and requires immediate medical attention.
15Medical Conditions Associated with Popliteal Cysts Medical conditions associated with popliteal cysts, in descending order of frequency, are as follows:Arthritides: Osteoarthritis, RA, Juvenile RA, Gout, Reiter syndrome, psoriasis & systemic lupus erythematosus.Internal derangement: meniscal tears, ACL tears, osteochondral fracturesInfection: septic arthritis, tuberculosisChronic dialysisHemophiliaHypothyroidismPigmented villonodular synovitisSarcoidosis· In younger athletes a torn meniscus may be the underlying cause.· Herniation of the knee joint capsule out into the back of the knee, which is more common in adults. This type of Baker's cyst is commonly associated with a tear in the meniscal cartilage of the knee.· In older adults, osteoarthritis might be suspected as a possible cause.Any damage within the knee joint may cause swelling and therefore a Baker's Cyst.Patient Populations Prevalence, %RA 5-58, Osteoarthritis 42, Internal derangements 5-18
16Baker’s Cyst & Arthritis Arthritis is the most common condition associated with Baker cyst. Of the arthritides, osteoarthritis is probably the most common cause of popliteal cyst. Although prevalence of Baker cyst in patients with inflammatory arthritis is higher than in patients with osteoarthritis, osteoarthritis is much more common than inflammatory arthritis.Fam et al demonstrated that the occurrence of Baker cysts relates directly to the presence of knee effusion and severity of osteoarthritis.In 99 consecutive patients with RA, Andonopoulos et al demonstrated Baker cysts on US in 47 patients (48%). Twenty patients (20%) had bilateral cysts. Of 198 patients' knees, 67 (34%) had popliteal cysts, yet only 29 cysts (43%) were diagnosed clinically.
17Diagnosis of a Baker’s Cyst Arthrography (a type of x-ray examination that uses a contrast agent to image an anatomical joint): 5-46%Ultrasound: 40-42%Arthoscopy: 37%Cadaveric dissections 30%MRI 5-18%Any damage within the knee joint may cause swelling and therefore a Baker's Cyst.X-rays will not show the cyst or a meniscal tear but will show other abnormalities that may be present including arthritis.MRI can be helpful to visualize the cyst and to demonstrate any meniscal injury.
18Treatment of Baker’s Cyst Often no treatment is necessary and the practitioner can observe the cyst over time. If the cyst is painful, treatment is usually aimed at correcting the underlying problem, such as arthritis or a meniscus tear.Baker cysts often resolve with removal of excess knee fluid in conjunction with cortisone injection.Medications are sometimes given to relieve pain and inflammation.When cartilage tears or other internal knee problems are associated, surgery can be the best treatment option. During a surgical operation the surgeon can remove the synovium that leads to the cyst formation.Baker's cysts usually disappear spontaneously, but the time in which they do so is variable.Removal of the cyst is generally not done because it may damage nearby blood vessels and nerves. swollen tissue = synovium
19Patellofemoral Pain Syndrome (Chondromalacia patellae) Patellofemoral Syndrome is the term used to describe pain in and around the patellaFunctional AnatomyFull extension: Patella sits lateral to the trochleaDuring Flexion: Patella moves medial and comes to lie within the intercondylar notch until 130º, when it starts to move lateral again.Patella excursion is controlled by the quadriceps, particularly VMO & VLWith increasing knee flexion, a greater area of patellar articular surface comes into contact with the femur, therefore offsetting the increased load that comes with flexion
20Patellofemoral Pain Syndrome Cont. Loaded knee flexion activities subject the patellofemoral joint to loads many times the body weight.Anatomically, the lateral structures of the PFJ are much stronger than the medial structures, so any imbalance in the forces will cause the patella to drift laterally.ActivityForce through PFJLevel Walking0.5 x body weightGoing up stairs3-4 x body weightSquat7-8 x body weight
21Predisposing Factors Factors Cause Abnormal Biomechanics Excessive PronationFemoral anteversion (internal femoral torsion)High small patella (patella alta)Increased Q angleSoft tissue tightnessMuscles: Gastroc, H’strings, Rec Fem & ITBLateral Structures: Lateral retinaculum, ITB & VLMuscle DysfunctionVMOHip abductors / External rotators (glut med)TrainingDistance runningHills, stairsQ angle = angle between line of pull of Quads and line of patellar tendonFemoral anteversion often referred to as ‘squinting patella’ and is associated with an increased lateral force on the patella due to an increase in the valgus force that occurs during knee extension. Internal femoral torsion, in association with internal tibial rotation, can be secondary to excessive subtalar pronation. Internal femoral rotation can also occur in conjunction with external tibial rotation.Hip internal rotation can be limited by soft tissue restriction, such as tight anterior joint capsule and/or short adductors, TFL, ilipsoas and rec fem. All of these restrict movement in the knee and hip therefore predisposing to patellofemoral pain.Tightness in ITB results in overactivity in the TFL and diminished activity in the posterior fibres of glut med. The muscle imbalance persists because acting from a shortened position (that usually cross 2 joints) are readily recruited and strong, whereas muscles acting form an elongated position (usually postural muscles) are difficult to recruit and weak. A subject with a short ITB demonstrates excessive medial rotation of the hip during the stance phase of gait which means that the pelvis on the opposite side drops (trendelenberg sign). This hip movement will increase the dynamic Q angle and hence increase the potential for patellofemoral pain.Soft tissue tightness is particularly prevalent during the adolescent growth spurt. The resultant inflexibility alters stress through the PFJ and also compromises muscle control as the muscles attempt to control a much longer lever.Lateral structures are particularly tight, with the superficial structures (VL & ITB) restricting medial glide and the deep structures (lateral retinaculum) restricting medial tilt.H’string an gastroc tightness cause a lateral tracking of the patella by increasing the dynamic Q angle.When an individual with tight hamstrings runs, knee flexion increases with foot strike. Because the knee cannot strighten easily, ankle dorsiflexion must increase for the body to pass over the planted foot. If the talocrural joint is already maximally dorsiflexed, the foot will pronate, particularly at the subtalar joint. This increases the valgus vector force at the knee & hence increases the dynamic Q angle.Therefore altered foot biomechanics, as a secondary as well as a primary problem, can alter tibial rotation and affect patellofemoral joint mechanics.
22Tibial Apophysitis (Osgood-Schlatter Lesion) The typical patient is a 13- or 14-year-old boy (or a 10- or 11-year-old girl) who has recently gone through a growth spurt.Aggravated by:SquattingWalking up / down stairsForceful contraction of the quadricepsExacerbated by jumping and hurdling, because repetitive hard landings place excessive stress on the insertion of the patellar tendon.A teenage boy who presents with anterior knee pain localized to the tibial tuberosity is likely to have tibial apophysitis, or Osgood-Schlatter lesion3,4 (Figure 1).5 The typical patient is a 13- or 14-year-old boy (or a 10- or 11-year-old girl) who has recently gone through a growth spurt.The patient with tibial apophysitis generally reports waxing and waning of knee pain for a period of months. The pain worsens with squatting, walking up or down stairs, or forceful contractions of the quadriceps muscle. This overuse apophysitis is exacerbated by jumping and hurdling, because repetitive hard landings place excessive stress on the insertion of the patellar tendon.On physical examination, the tibial tuberosity is tender and swollen, and may feel warm. The knee pain is reproduced with resisted active extension or passive hyperflexion of the knee. No effusion is present. Radiographs are usually negative; rarely, they show avulsion of the apophysis at the tibial tuberosity. However, the physician must not mistake the normal appearance of the tibial apophysis for an avulsion fracture.
23Anterior & Posterior Cruciate Ligaments Two important intra-articular ligaments that provide static support to the knee are the anterior (ACL) and posterior (PCL) cruciate ligaments. The PCL and ACL are intra-articular but extrasynovialThe ACL originates from the medial and anterior aspect of the tibial plateau and runs superiorly, laterally, and posteriorly toward its insertion on the lateral femoral condyleThe ACL is composed of the anteriomedial and posteriolateral bundles. Together, these bundles provide approximately 85% of total restraining force of anterior displacement of the tibia on the femurTo a lesser degree, the ACL checks extension and hyperextension. Together with the posterior cruciate ligament (PCL), It also prevents excessive tibial medial and lateral rotation, as well as varus and valgus stressesThe ligaments are tense in all positions, but increase their tension in the extremes of flexion and extensionThe PCL is the major stabilizer of the knee. It provides most of the restraint against posterior tibial displacement on the femur during flexion. The posterior fibers of the PCL prevent hyperextension. During flexion, the anterior fibers tighten and help prevent hyperflexion. The PCL resists internal tibial rotation during flexion by winding around the anterior cruciate ligament (ACL).In terminal knee extension, the PCL and ACL, with the guidance of the menisci, help externally rotate the tibia to its correct position in relation to the femur (screw home mechanism).The meniscofemoral ligaments (MFL) are associated intimately with the PCL. Their function is to pull the posterior horn of the lateral meniscus anterior and medial during flexion, balancing the action of the popliteus muscle, which, in addition to the MFL, attaches to the posterior horn of the lateral meniscus. The MFL also may function as a secondary restraint to posterior tibial translation after complete rupture of the PCLThe PCL is twice as strong as the ACL. It contains a larger cross-sectional area and possesses a higher tensile strength, explaining its lower rate of injury. The PCL fibers are oriented more vertically than the more oblique fibers of the ACL.
24Anterior Cruciate Ligament The anterior cruciate ligament (ACL) is one of the most commonly injured ligaments of the knee. Each year, approximately 100,000 people sustain ACL injuries with basketball, soccer, skiing, and gymnastics being the sports with the highest incidenceACL injury rates are estimated to be two to eight times higher in females than males participating in the same sportsNumerous studies exploring why females are at a higher risk cite both intrinsic and extrinsic differences between genders
25Anatomy and Biomechanics Smaller notch width index. A smaller notch width index has been found to predispose females to ACL injuries. The smaller notch likely causes a shearing effect on the ACL by the femur. Although this smaller, A-shaped notch has been shown to be related to ACL injuries, there is no evidence that the relationship is causalIncreased ligamentous laxity. Females in general have ligaments that are more lax than males, which increases the risk of ACL rupture. In addition, it has been suggested that within the first year after surgery when “ligamentization” of the tendon occurs, females undergo a different remodeling response than malesIncreased Q angle. The female pelvis is wider than the male pelvis, which increases the Q angle of the knee. This leads to increase stresses at the knee, and causes other compensatory deviations in the surrounding joints. Other changes that occur include femoral anteversion, tibial external torsion, and subtalar pronationThe cause of increased female susceptibility to ACL injury is unclear, but is likely due to a multitude of complex variables. Research has suggested three main views: anatomical and biomechanical considerations, neuromuscular imbalances, and hormonal influences.
26Neuromuscular Imbalances Research has shown disparity among females and males in knee proprioception and neuromuscular controlQuadriceps dominance pattern. Females demonstrate strength imbalance between quadriceps and hamstrings. Female athletes tend to rely on their quadriceps and gastrocnemius and less on their hamstrings when compared to males. In addition, females exhibited a delayed firing pattern of the hamstringsLanding strategies. Females use different strategies when running, landing, or jumping than males and tend to land with an increased valgus moment. This may cause significant differences between their dominant and non-dominant knee. However, both knees may potentially be at an increased risk for ACL rupture. The dominant knee works to limit gravitational forces, while the non-dominant knee may be too weak to withstand such forces
27Hormonal InfluencesFemale hormones have been suggested as a possible risk factor for ACL rupture. It has been hypothesized that these hormones increase ligament laxity and decrease ligament strength during the weeks prior to and immediately following the menstrual cycle.However, further research is needed to confirm or deny the role of female sex hormones in ACL injury.Most research on this topic has several limiting factors, including the reliance on subject self-report of menstrual cycle phase or the confounding factor of oral contraceptives [ 10 ].
28Mechanism of InjuryThe ACL is usually torn as a result of a quick deceleration, hyperextension or rotational injury that usually does not involve contact with another individual. This injury often occurs following a sudden change of directionWhen hit from the side, injuries to the ACL are often associated with medial meniscus and medial collateral ligament (MCL) tears, collectively known as the “unhappy triad.”In adolescents, the ACL may avulse from the tibial spine instead of rupturing
29Signs and SymptomsAn acute ACL rupture is characterized by pain, hemarthrosis, and instability. At the moment of injury, many people report hearing or feeling a popping sensationCommon impairments typically include immediate swelling (0-2 hours), decreased strength and range of motion, inability to weight-bear and poor balance and coordinationConsiderable pain in the knee that does not go away within the first few hours after the injuryPatients are functionally limited in their ability to ambulate, negotiate stairs, and perform basic and instrumental ADLs. If not properly addressed, these impairments could become chronic conditionsA feeling of unsteadiness and a tendency for the knee to "give-way," or an inability to bear weight on the injured legAn audible "pop" or the perception of something snapping or breaking at the moment of injuryA feeling of "fullness or tightness" in the knee
31Investigations: X-ray The specific indications for x-ray following acute knee injury are:High speed injuries (suspect a tibial plateau fractureChildren or adolescents (who may avulse a bony fragment instead of tearing of a cruciate ligament)If there is clinical suspicion of loose bodiesIf hemarthrosis is presentIf surgery is indicated