Lower extremities Knee pathologies chapter 10
tibiofemoral joint dislocation
-result of hyperextension with tibial rotation, posterior displacement. Must be immediately evaluated by a physician. Prior to transporting, establish distal pulses, immobilize the limb in the position it was found, treat for shock
menisci purpose
1.deepen the articulation and fill the gaps that normally occur during the knees articulation, increasing load transmission over a greater percentage of the joint surfaces 2. improve lubrication 3. provide shock absorption 4. increase passive joint stability 5. limit the extremes of flexion and extension 6. serve as proprioceptive organs
factors that limit anterior draw test
1.need to overcome the effects of gravity while moving the tibia anteriorly 2. guarding by the hamstring group, masking anterior displacement of the tibia 3. effusion within the capsule, providing resistance to movement or inability to flex at 90 degrees
McMurray's test
A test for injury to meniscal structures of the knee in which the lower leg is rotated while the leg is extended; pain and a cracking in the knee indicates meniscal injury
ruptured patellar tendon
A unilaterally high riding patella, when accompanied by spasm of the quadriceps muscle group, indicate this
The ACL serves as a static stabilizer against?
Anterior translation of the tibia on the femur Internal rotation of the tibia on the femur External rotation of the tibia on the femur Hyperextension of the tibiofemoral joint
What are the two discrete segments of the ACL?
Anteromedial bundle and posterolateral bundle and are named for their attachment site on the tibia
hemarthrosis
Bleeding into a joint, usually due to severe trauma
Passive range of motion
Extension-is assessed with the tibia slightly elevated by placing a bolster under the distal tibia with the patient in the supine position. Flexion-patient supine and the hip flexed to remove the influence of excessive rectus femoris tightness
Inspection of the posterior structures
Hamstring muscle group-observe the length of the hamstring group for signs of contusion such as ecchymosis and edema. Popliteal fossa-inspect the popliteal fossa for sign of swelling or discoloration
Baker's cyst
Involve only the bursa of the semimembranosus and medial head of the gastrocnemius. The cyst itself is not the cause of the problem but more indicative of pathology within the knee
inspection of the lateral structures
Lateral aspect of the tibia, joint line. and femur for swelling. Fibular head-note the head of the fibula normally aligned at an equal height compared with the opposite side. Posterior sag of the tibia-patient lying supine and the knees flexed to 90 degrees and observe the relative positions of the tibia. Hyperextension-view standing patient from the side. Hyperextension indicated by the posterior bowing of the knee
Inspection of the anterior structures
Observe the patella. Shifting of the patella away from its central position on the trochlea may indicate patella malalignment or dislocation which occur laterally.
iliotibial band friction sydndrome
Pain localized over lateral femoral condyle typically caused by overuse. Most common in runners.
What two bones directly affect the knee's function and ability?
Patella and tibiofibular syndesmosis
prone Lachman's test
Patient is prone with leg hanging off the end of the table, knee passively flexed to 3
Medial collateral ligament sprains
The MCL is damaged as the result of tensile forces, most commonly a valgus stress casued by a blow to the lateral aspect of the knee
Anterolateral rotatory instabilty
The most common rotational instability of the knee. Three tests used. Pivot shift, Slocum ALRI test, and the crossover test.
Ober's test
The patient is positioned in sidelying with the lower leg flexed at the hip and the knee. The therapist moves the test leg into hip extension and abduction and then attempts to slowly lower the test leg. A positive test is indicated by an inability of the test leg to adduct and touch the table and may be indicative of a tensor fasciae latae contracture.
what separates the popliteal artery and vein
They are separated from the posterior capsule by a layer of adipose tissue
ballotable patella test
To determine the presence of excess fluid in the knee by tapping on the patella.
popliteofibular ligament
Y-shaped structure with origins from the tibia and fibula and inserting on the femur, is a key stabilizer against posterior translation, varus forces and external rotation
osteochondral lesions
a series of disorders including osteochondral defects and osteochondritis that involve a joint articular cartilage and underlying subchondral bone
menisci pink zone
a thin light vascular between the red and white zones
vascular testing
an examination of distal pulses (posterior tibial artery, dorsal pedal artery) is indicated if a dislocation of the tibiofemoral joint is suspected
femoral trochlea
anterior depression forms through which the patella glides as the knee flexes and extends
Stress testing two tests
anterior drawer test involve placing the knee in 90 degrees of flexion and attempting to translate the tibia anteriorly. Lachman's test-isolate the posterolateral bundle of the ACL because the knee is flexed to 20 degrees.
How is the meniscus divided?
anterior, middle, and posterior third. The anterior and posterior portions are marked by horns-the area most frequently torn
What are the distinct components of the PCL?
anterolateral and posteromedial bundles
Anterior cruciate ligament (ACL)
arises from the anteromedial intercondylar eminence of the tibia, travels posteriorly, and passes lateral to the posterior cruciate ligament (PCL)
adductor tubercle
arises off the superior crest of the medial epicondyle and serve as attachment sites for tendons for functioning of the muscle
deep fibers of the IT band
attach to the lateral joint capsule and function as an anterolateral knee ligament playing a significant role in knee stability and patellofemoral pathology
slocum drawer test
attempts to isolate either the anteromedial or the anterolateral joint capsule. Internally rotating the tibia checks for the presence of ALRI. Externally rotating it checks for AMRI
lateral meniscus
circular in shape but the thickness, shape and mobility are different than those of the medial meniscus. Both medial and lateral are attached at their peripheries to the tibia via the coronary ligament
quadriceps muscle group
compare the mass and tone of the quadriceps muscle groups bilaterally and confirm andy apparent deficits through girth measurements
intercondylar notch
condyles share a common anterior surface, then diverge posteriorly and are separated by this
medial and lateral condyles
convex structures covered with articular hyaline cartilage that articulate with the tibia via the menisci
medial and lateral tibial plateus
correspond to the femoral condyles. The medial tibial plateau is concave in both the frontal and sagittal planes. The lateral is concave in the frontal plane and convex in the sagittal plane. Medial is 50% larger
lateral collateral ligament (LCL)
does not attach to the joint capsule or meniscus. This cordlike structure arises from the lateral femoral epicondyle sharing a common site of origin with the lateral joint capsule and inserts on the proximal aspect of the fibular head
pivot shift test
duplicates the anterior subluxation and reduction that occurs during functional activities in ACL deficient knees
on field palpation
extensor mechanism- palpate the length of the patellar tendon, patella, quadriceps tendon, and distal quad medial collateral ligament and medial joint line-note any point tenderness along the joint line lateral collateral ligament and lateral joint line- palpate the LCL and areas for tenderness fibular head-palpate the fibular head to rule out the presence of a fracture and determine the stability of the proximal tibiofibular syndesmosis
tiblofemoral joint
femur, menisci, and the tibia all function together
presence of the medial and lateral articular condyles classifies the tibiofemoral joint as a double condyloid articulation capable of these three degrees of freedom
flexion and extension internal and external rotation abduction and adduction
Active range of motion
flexion and extension-the normal arc of motion for knee flexion and extension is 135 to 145 degrees with the majority of the motion occurring as flexion. A fully extended knee is at 0 degrees but may be as great as 10 or more degrees beyond 0 (genu recurvatum) Internal and external rotation- to allow for full ROM during knee flexion and extension, the tibia must internally and externally rotate on the femur
Extravasate
fluid escaping from vessels into the surrounding tissue
menisci avascular (white) zone
formed by the inner portion of the meniscus
popliteus complex
formed by the popliteus muscle and its tendon, the popliteofibular ligament, popliteobial fascicle, and the popliteomensical fascicles.
meniscal cysts
frequently associated with longitudinal meniscal tears become symptomatic because of localized swelling. After a longitudinal tear along the periphery of the meniscus, breaches are formed in the joint capsule that fills with synovial fluid
popliteus tendinopathy
gap in the tendon of the popliteus. Popliteus is quite an uncommon pathology which often occurs in athletes and people with a history of other knee ligament injuries after trauma. It is a relatively unusual condition in non-athletes without a history of Knee traumas.
Hyperextension of knee
genu recurvatum posterior bowing of the knee
Pes anserine muscle group
gracilis, sartorius, andsemitendinosus muscles. This group internally rotates the tibia when the foot is not planted on the ground. When the foot is planted, it rotates the femur on the fixed tibia
Noble compression test
identifies if distal iliotibial (IT) band friction syndrome is present
on field ligamentous test
if ligamentous injury is suspected, valgus stress testing varus stress testing, Lachman's test, and posterior drawer test should be done
discoid meniscus
increased thickness and covers a larger area of the tibia, congenital thickening cartilage, girls, "clinical snapping syndrome," pain, effusion, Xray: wide lateral compartment, hypoplasia lateral femoral condyle, partial meniscectomy
Inspection of medial structures
inspect the medial aspect of the knee joint to note any swelling or discoloration along the tibia, knee joint line, femur, or pes anserine tendon. Inspect the vastus medialis and pay attention to the oblique fibers
rotational knee instabilities
involve abnormal internal or external rotation at the tibiofemoral joint. Named for the direction in which the tibia subluxates on the femur. Result when multiple structures are traumatized often the result of rotational forces placed on the knee
flexion-rotation drawer test (FRD)
involves the stabilization of the tibia, resulting in the relative subluxation of the femur
iliotibial band (IT band)
is an extension of the tensor fascia latae and gluteus maximus muscular fascia. It travels down the lateral aspect of the femur to the Gerdy's tubercle and attaches to the lateral patellar retinaculum
anterior horns of meniscus
joined by the transverse ligament and connected to the patellar tendon via patellomeniscal ligaments
synovial capsule
lines the articular portions of the fibrous joint capsule
menisci narrow vascular (red) zone
located along their outer rim and the anterior and posterior horns
on field history
location of the pain mechanism of injury history of injury associated sounds and sensations associated neurologic symptoms
history of present condition
location of the pain mechanism of injury weight-bearing status at the time of injury associated sounds or sensations(pop or snap) onset of injury
Tibial tuberosity problems
look for possible enlargement of this area. In adolescents could mean Osgood-Schlatter's disease
arthrometers
measure the amount of tibial translation in a more accurate, quantitative, reproducible manner and are less prone to the physical limitation faced by the clinician when performing the anterior drawer or lachman's test, reliability depends on the skill and experience of the clinician
jerk test
modification of the lateral pivot shift test. The patient's hip is flexed to 45 degrees and the knee flexed to 90. A valgus and internal rotation force is applied as the knee is extended
alignment of the femur on the tibia
observe angle at which the medial tibia and femur articulate. The angle ranges from 180-185 degrees
Past medical history evaluation
past history of injury injury to related body areas general medical condition
on field inspection
patellar position-properly seated within the femoral trochlea alignment of the tibiofemoral joint-make sure properly aligned
functional assessment
patient is observed while performing those tasks that are problematic to the start the process of identifying the impairments
palpation
performed to confirm findings during inspection and identify traumatized tissues. The knee should be palpated in 90 degrees of flexion when possible
uniplanar knee sprains
present with instability in only one of the body's cardinal planes. Damage to the MCL or LCL leads to valgus or varus instability in the frontal plane
medial collateral ligament (MCL)
primary medial stabilizer of the knee and consists of a deep layer and superficial layer
popliteal fossa
primary neurologic and vascular structures serving the knee and points distal pass through this. The knee is supplied primarily by the L3 L4 L5 S1 and S2 nerve roots
popliteus muscle
provides both dynamic and static stabilization to the knee, resisting posterior tibial translation, static external tibial rotation, dynamic internal tibial rotation, and buffers against varus forces
arcuate ligament
provides further support to the posterolateral joint capsule. It arises from the fibular head and passes over the popliteus muscle where it diverges into the intercondylar area of the tibia and the posterior aspect of the femur's lateral epicondyle
tibiofibular syndesmosis
proximal fibula
Valgus stress test
pt in supine with entire LE supported and knee flexed to 20-30 deg. PT places one hand on medial surface of ankle and other hand on lateral surface of knee. PT applies valgus force to the knee with distal hand. (+) excess valgus movement and/or pain. Indicates MCL sprain. Note: a (+) test with knee in full extension may be indicative of damage to MCL, PCL, posterior oblique ligament, posteromedial capsule
proximal tibiofibular syndesmosis
relatively immobile joint where the proximal tibia and fibula are bond together by ligaments
Renne's test
replicates the mechanics of the Noble compression test but is performed with the patient standing on the involved leg and flexing the knee. No pressure is applied to the lateral femoral epicondyle
medial meniscus
resembles a half crescent or C shape that is wider posteriorly than it is anteriorly
lateral collateral ligament sprains
results from a blow to the medial knee that places tensile forces on the lateral structures or by internal rotation of the tibia on the femur, LCL sprains result in varus laxity of the knee.
crossover test
semifunctional test used to determine the rotational stability of the knee
superficial later
separated from the deep layer by bursa is this layer
Patella
sesamoid bone located in the patellar tendon that improves the mechanical function of the quadriceps during knee extension and dissipates the force received from the extensor mechanism and protects the anterior portion of the knee
popliteofibular ligament other names for
short external lateral ligament popliteofibular fascicles fibular origin of the popliteus plpliteofibular fibers
fibrous joint capsule
surrounds the circumference of the knee joint
patellar tendon
swelling over or around the patellar tendon, indicates tendinopathy or bursitis.
Wilson's test
test used to detect the presence of Osteochondritis dissecans of the knee.
sweep test
tests for joint effusion; positive test will reveal a formation of edema on medial side when lateral pressure is applied
screw home mechanism
the PCL and the ACL wind upon each other in flexion and unwind in extension. Damage to the PCL can result in an unstable knee
on field range of motion test
the athlete actively flex and extend the knee throughout the ROM. Inability means the patient should be transported in nonweight bearing manner from the field
linea aspera
the femur's posterior aspect is demarcated by this which is a bony ridge spanning the length of the shaft
meniscofemoral ligaments
the ligaments of Humphrey and Wrisberg are meniscofemoral ligaments which run from the posterior horn of the lateral meniscus to the lateral aspect of the medial femoral condyle;
femur
the longest and strongest bone in the body. Is one quarter of the body's total height
extensor mechanism
the mechanism formed by the quadricep and patellorfemoral joint responsible for casuing extension of the lower leg at the knee joint
What is the hamstring muscle group?
the semitendinosus, semimembranosus, and the biceps femoris. They act to flex the knee and extend the hip
tibial tuberosity
the site of the patellar tendon's distal attachment and is located on the proximal portion of the anterior tibia
deep layer
thickening of the joint capsule and is attached to the medial meniscus
autograft
tissues used to replace the ligament harvest from the patients body (bone-patellar tendon bone, hamstring
allograft
tissues used to replace the ligament obtained from a cadaver
Apley's compression and distraction test
to identify tears in the posterior horn of the meniscus. It is able to identify lesions to any part of the meniscus
varus stress test
used to determine the integrity of the LCL, lateral joint capsule, IT band, posterior lateral complex, crucial ligaments, and lateral musculature when performed in complete extension
Godfrey's test
uses gravity to increase the posterior sag as noted during inspection process
posterior drawer test
using same position as anterior drawer, it is attempted to displace the tibia posteriorly
what are the four muscle groups of the quadricep femoris?
vastus lateralls vastus intermedius vastus medialis rectus femoris
Thessaly test
weight bearing procedure has reported high values for identifying meniscal tears
fabella
when present, lies within the lateral head of the gastrocnemius muscle. A fabellofibular ligament attaches from the fabella to the fibular head, increasing the thickness of the tissues in the posterolateral corner of the knee
lateral epicondyle
wider and emanates from the femoral shaft at a lesser angle than the medial epicondyle.
